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<?xml version="1.0" encoding="utf-8"?>
<search>
<entry>
<title>request control</title>
<link href="2021/06/21/request-control/"/>
<url>2021/06/21/request-control/</url>
<content type="html"><![CDATA[<h2 id="过滤器-Filter-介绍"><a href="#过滤器-Filter-介绍" class="headerlink" title="过滤器(Filter)介绍"></a><strong>过滤器(Filter)介绍</strong></h2><p>Filter可以认为是Servlet的一种“加强版”，它主要用于对用户请求进行预处理，也可以对HttpServletResponse进行后处理，是个典型的处理链。Filter也可以对用户请求生成响应，这一点与Servlet相同，但实际上很少会使用Filter向用户请求生成响应。使用Filter完整的流程是：Filter对用户请求进行预处理，接着将请求交给Servlet进行预处理并生成响应，最后Filter再对服务器响应进行后处理。</p><p>定义过滤条件</p><pre class=" language-java"><code class="language-java"><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">UserFilter</span> <span class="token keyword">implements</span> <span class="token class-name">Filter</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">doFilter</span><span class="token punctuation">(</span>ServletRequest servletRequest<span class="token punctuation">,</span> ServletResponse servletResponse<span class="token punctuation">,</span> FilterChain filterChain<span class="token punctuation">)</span> <span class="token keyword">throws</span> IOException<span class="token punctuation">,</span> ServletException <span class="token punctuation">{</span> HttpServletRequest request <span class="token operator">=</span> <span class="token punctuation">(</span>HttpServletRequest<span class="token punctuation">)</span> servletRequest<span class="token punctuation">;</span> HttpServletResponse response <span class="token operator">=</span> <span class="token punctuation">(</span>HttpServletResponse<span class="token punctuation">)</span> servletResponse<span class="token punctuation">;</span> HttpSession session <span class="token operator">=</span> request<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">if</span><span class="token punctuation">(</span>session<span class="token punctuation">.</span><span class="token function">getAttribute</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">)</span> <span class="token operator">==</span> null<span class="token punctuation">)</span><span class="token punctuation">{</span> response<span class="token punctuation">.</span><span class="token function">sendRedirect</span><span class="token punctuation">(</span><span class="token string">"/login"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">else</span><span class="token punctuation">{</span> filterChain<span class="token punctuation">.</span><span class="token function">doFilter</span><span class="token punctuation">(</span>servletRequest<span class="token punctuation">,</span>servletResponse<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>需要过滤的请求</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Configuration</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">FilterConfig</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Bean</span> <span class="token keyword">public</span> FilterRegistrationBean <span class="token function">filterRegistrationBean</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> FilterRegistrationBean filterRegistrationBean <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">FilterRegistrationBean</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> filterRegistrationBean<span class="token punctuation">.</span><span class="token function">setFilter</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">UserFilter</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> filterRegistrationBean<span class="token punctuation">.</span><span class="token function">addUrlPatterns</span><span class="token punctuation">(</span><span class="token string">"/cart/*"</span><span class="token punctuation">,</span><span class="token string">"/orders/*"</span><span class="token punctuation">,</span><span class="token string">"/user/userInfo"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> filterRegistrationBean<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>创建Filter必须实现javax.servlet.Filter接口，在该接口中定义了如下三个方法。</p><ul><li>void init(FilterConfig config):用于完成Filter的初始化。</li><li>void destory():用于Filter销毁前，完成某些资源的回收。</li><li>void doFilter(ServletRequest request,ServletResponse response,FilterChain chain):实现过滤功能，该方法就是对每个请求及响应增加的额外处理。该方法可以实现对用户请求进行预处理(ServletRequest request)，也可实现对服务器响应进行后处理(ServletResponse response)—它们的分界线为是否调用了chain.doFilter(),执行该方法之前，即对用户请求进行预处理；执行该方法之后，即对服务器响应进行后处理。</li></ul><h2 id="拦截器-Interceptor-介绍"><a href="#拦截器-Interceptor-介绍" class="headerlink" title="拦截器(Interceptor)介绍"></a><strong>拦截器(Interceptor)介绍</strong></h2><p>拦截器，在AOP(Aspect-Oriented Programming)中用于在某个方法或字段被访问之前，进行拦截，然后在之前或之后加入某些操作。拦截是AOP的一种实现策略。</p><p>拦截规则</p><pre class=" language-java"><code class="language-java"><span class="token comment" spellcheck="true">/* * 拦截器类,重写HandlerInterceptor的三个方法 * */</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">UserInterceptor</span> <span class="token keyword">implements</span> <span class="token class-name">HandlerInterceptor</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">boolean</span> <span class="token function">preHandle</span><span class="token punctuation">(</span>HttpServletRequest request<span class="token punctuation">,</span> HttpServletResponse response<span class="token punctuation">,</span> Object handler<span class="token punctuation">)</span> <span class="token keyword">throws</span> Exception <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//拦截规则，从session中获取用户信息</span> User user <span class="token operator">=</span> <span class="token punctuation">(</span>User<span class="token punctuation">)</span> request<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getAttribute</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//判断用户是否为空</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>null <span class="token operator">==</span> user<span class="token punctuation">)</span> <span class="token punctuation">{</span> response<span class="token punctuation">.</span><span class="token function">sendRedirect</span><span class="token punctuation">(</span>request<span class="token punctuation">.</span><span class="token function">getContextPath</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token string">"/index"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token boolean">false</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">return</span> <span class="token boolean">true</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">postHandle</span><span class="token punctuation">(</span>HttpServletRequest request<span class="token punctuation">,</span> HttpServletResponse response<span class="token punctuation">,</span> Object handler<span class="token punctuation">,</span> ModelAndView modelAndView<span class="token punctuation">)</span> <span class="token keyword">throws</span> Exception <span class="token punctuation">{</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">afterCompletion</span><span class="token punctuation">(</span>HttpServletRequest request<span class="token punctuation">,</span> HttpServletResponse response<span class="token punctuation">,</span> Object handler<span class="token punctuation">,</span> Exception ex<span class="token punctuation">)</span> <span class="token keyword">throws</span> Exception <span class="token punctuation">{</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>要拦截的请求</p><pre class=" language-java"><code class="language-java"><span class="token comment" spellcheck="true">/* * 类上有@Configuration，表示这个类为配置类，表示是一个xml配置文件 * */</span><span class="token annotation punctuation">@Configuration</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">SystemConfig</span> <span class="token keyword">implements</span> <span class="token class-name">WebMvcConfigurer</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">addInterceptors</span><span class="token punctuation">(</span>InterceptorRegistry registry<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//定义要拦截的路径</span> String<span class="token punctuation">[</span><span class="token punctuation">]</span> path <span class="token operator">=</span> <span class="token punctuation">{</span> <span class="token string">"/emp/**"</span> <span class="token punctuation">}</span><span class="token punctuation">;</span> registry<span class="token punctuation">.</span><span class="token function">addInterceptor</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">UserInterceptor</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token punctuation">.</span><span class="token function">addPathPatterns</span><span class="token punctuation">(</span>path<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>创建Interceptor必须实现com.opensymphony.xwork2.interceptor.Interceptor接口，该接口定义了如下三个方法。</p><ul><li>void init():在该拦截器被实例化之后，在该拦截器执行拦截之前，系统将回调该方法。对于每个拦截器而言，其init()方法只执行一次。因此，该方法的方法体主要用于初始化资源。</li><li>void destory():该方法与init()方法对应。在拦截器实例被销毁之前，系统将回调该拦截器的destory方法，该方法用于销毁在init方法里打开的资源。</li><li>String intercept(ActionInvocation invocation):该方法是用户需要实现的拦截动作。就像Action的execute方法一样。intercept方法会返回一个字符串作为逻辑视图。如果该方法直接返回了一个字符串，系统会将跳转到该逻辑视图对应的实际视图资源，不会调用被拦截的Action。该方法的ActionInvocation参数包含了被拦截的Action的引用，可以通过调用该参数的invoke方法，将控制权转给下一个拦截器，或者转给Action的execute方法(如果该拦截器后没有其他拦截器，则直接执行Action的execute方法)。</li></ul><h2 id="Filter和Interceptor的区别"><a href="#Filter和Interceptor的区别" class="headerlink" title="Filter和Interceptor的区别"></a><strong>Filter和Interceptor的区别</strong></h2><ul><li>Filter是基于函数回调的，而Interceptor则是基于Java反射的。</li><li>Filter依赖于Servlet容器，而Interceptor不依赖于Servlet容器。</li><li>Filter对几乎所有的请求起作用，而Interceptor只能对action请求起作用。</li><li>Interceptor可以访问Action的上下文，值栈里的对象，而Filter不能。</li><li>在action的生命周期里，Interceptor可以被多次调用，而Filter只能在容器初始化时调用一次。</li><li><strong>拦截器可以获取IOC容器中的各个bean，而过滤器就不行，这点很重要，在拦截器里注入一个service，可以调用业务逻辑。</strong></li></ul>]]></content>
<tags>
<tag> Filter </tag>
<tag> Interceptor </tag>
</tags>
</entry>
<entry>
<title>java 异常</title>
<link href="2021/06/20/java-yi-chang/"/>
<url>2021/06/20/java-yi-chang/</url>
<content type="html"><![CDATA[<h2 id="Java异常简介"><a href="#Java异常简介" class="headerlink" title="Java异常简介"></a>Java异常简介</h2><p>1.所有的异常都是从Throwable继承而来的，是所有异常的共同祖先。</p><p>2.Throwable有两个子类，Error和Exception。其中Error是错误，对于所有的编译时期的错误以及系统错误都是通过Error抛出的。这些错误表示故障发生于虚拟机自身、或者发生在虚拟机试图执行应用时，如Java虚拟机运行错误（Virtual MachineError）、类定义错误（NoClassDefFoundError）等。这些错误是不可查的，因为它们在应用程序的控制和处理能力之 外，而且绝大多数是程序运行时不允许出现的状况。对于设计合理的应用程序来说，即使确实发生了错误，本质上也不应该试图去处理它所引起的异常状况。在 Java中，错误通过Error的子类描述。</p><p>3.Exception，是另外一个非常重要的异常子类。它规定的异常是程序本身可以处理的异常。异常和错误的区别是，异常是可以被处理的，而错误是没法处理的。 </p><p>4.Checked Exception</p><p>可检查的异常，这是编码时非常常用的，所有checked exception都是需要在代码中处理的。它们的发生是可以预测的，正常的一种情况，可以合理的处理。比如IOException，或者一些自定义的异常。除了RuntimeException及其子类以外，都是checked exception。</p><p>5.Unchecked Exception</p><p>RuntimeException及其子类都是unchecked exception。比如NPE空指针异常，除数为0的算数异常ArithmeticException等等，这种异常是运行时发生，无法预先捕捉处理的。Error也是unchecked exception，也是无法预先处理的。</p><p><img src="https://img-blog.csdn.net/20180920165502957?watermark/2/text/aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pY2hhZWxnbw==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70" alt=" Java异常架构"></p><h2 id="异常关键字"><a href="#异常关键字" class="headerlink" title="异常关键字"></a>异常关键字</h2><p>1 try – 用于监听。将要被监听的代码(可能抛出异常的代码)放在try语句块之内，当try语句块内发生<br>异常时，异常就被抛出。<br>2 catch – 用于捕获异常。catch用来捕获try语句块中发生的异常。<br>3 finally – finally语句块总是会被执行。它主要用于回收在try块里打开的物力资源(如数据库连接、<br>网络连接和磁盘文件)。只有finally块，执行完成之后，才会回来执行try或者catch块中的return或<br>者throw语句，如果finally中使用了return或者throw等终止方法的语句，则就不会跳回执行，直<br>接停止。<br>4 throw – 用于抛出异常。<br>5 throws – 用在方法签名中，用于声明该方法可能抛出的异常。</p><h2 id="异常的处理"><a href="#异常的处理" class="headerlink" title="异常的处理"></a>异常的处理</h2><p>代码中的异常处理其实是对可检查异常的处理。</p><ol><li>通过try…catch语句块来处理：</li></ol><pre class=" language-java"><code class="language-java"><span class="token keyword">try</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 程序代码</span><span class="token punctuation">}</span><span class="token keyword">catch</span><span class="token punctuation">(</span>ExceptionName e1<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//Catch 块</span><span class="token punctuation">}</span></code></pre><p>Catch 语句包含要捕获异常类型的声明。当保护代码块中发生一个异常时，try 后面的 catch 块就会被检查。</p><p>如果发生的异常包含在 catch 块中，异常会被传递到该 catch 块，这和传递一个参数到方法是一样。</p><ol start="2"><li>另外，也可以在具体位置不处理，直接抛出，通过throws/throw到上层再进行处理，具体的，如果一个方法没有捕获到一个检查性异常，那么该方法必须使用 throws 关键字来声明。throws 关键字放在方法签名的尾部。也可以使用 throw 关键字抛出一个异常，无论它是新实例化的还是刚捕获到的。</li></ol><p>下面方法的声明抛出一个 RemoteException 异常：</p><pre class=" language-java"><code class="language-java"><span class="token keyword">import</span> java<span class="token punctuation">.</span>io<span class="token punctuation">.</span>*<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">className</span><span class="token punctuation">{</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">deposit</span><span class="token punctuation">(</span><span class="token keyword">double</span> amount<span class="token punctuation">)</span> <span class="token keyword">throws</span> RemoteException <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// Method implementation</span> <span class="token keyword">throw</span> <span class="token keyword">new</span> <span class="token class-name">RemoteException</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token comment" spellcheck="true">//Remainder of class definition</span><span class="token punctuation">}</span></code></pre><ol start="3"><li>finally关键字</li></ol><p>finally 关键字用来创建在 try 代码块后面执行的代码块。</p><p>无论是否发生异常，finally 代码块中的代码总会被执行。</p><p>在 finally 代码块中，可以运行清理类型等收尾善后性质的语句。</p><p>finally 代码块出现在 catch 代码块最后，语法如下：</p><pre class=" language-java"><code class="language-java"><span class="token keyword">try</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 程序代码</span><span class="token punctuation">}</span><span class="token keyword">catch</span><span class="token punctuation">(</span>异常类型<span class="token number">1</span> 异常的变量名<span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 程序代码</span><span class="token punctuation">}</span><span class="token keyword">catch</span><span class="token punctuation">(</span>异常类型<span class="token number">2</span> 异常的变量名<span class="token number">2</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 程序代码</span><span class="token punctuation">}</span><span class="token keyword">finally</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 程序代码</span><span class="token punctuation">}</span></code></pre><h2 id="常见的-RuntimeException"><a href="#常见的-RuntimeException" class="headerlink" title="常见的 RuntimeException"></a>常见的 RuntimeException</h2><p>ClassCastException(类转换异常)<br>IndexOutOfBoundsException(数组越界)<br>NullPointerException(空指针)<br>ArrayStoreException(数据存储异常，操作数组时类型不一致)<br>还有IO操作的BufferOverflowException异常</p><h2 id="Error-和-Exception-区别"><a href="#Error-和-Exception-区别" class="headerlink" title="Error 和 Exception 区别"></a>Error 和 Exception 区别</h2><p>Error 类型的错误通常为虚拟机相关错误，如系统崩溃，内存不足，堆栈溢出等，编译器不会对这<br>类错误进行检测，JAVA 应用程序也不应对这类错误进行捕获，一旦这类错误发生，通常应用程序<br>会被终止，仅靠应用程序本身无法恢复；<br>Exception 类的错误是可以在应用程序中进行捕获并处理的，通常遇到这种错误，应对其进行处<br>理，使应用程序可以继续正常运行。</p><h2 id="throw-和-throws"><a href="#throw-和-throws" class="headerlink" title="throw 和 throws"></a>throw 和 throws</h2><p>Java 中的异常处理除了包括捕获异常和处理异常之外，还包括声明异常和拋出异常，可以通过<br>throws 关键字在方法上声明该方法要拋出的异常，或者在方法内部通过 throw 拋出异常对象。<br><strong>throws 关键字和 throw 关键字在使用上的几点区别如下：</strong></p><p>throw 关键字用在方法内部，只能用于抛出一种异常，用来抛出方法或代码块中的异常，受查异常<br>和非受查异常都可以被抛出。<br>throws 关键字用在方法声明上，可以抛出多个异常，用来标识该方法可能抛出的异常列表。一个<br>方法用 throws 标识了可能抛出的异常列表，调用该方法的方法中必须包含可处理异常的代码，否<br>则也要在方法签名中用 throws 关键字声明相应的异常。</p><h2 id="final、finally、finalize-区别？"><a href="#final、finally、finalize-区别？" class="headerlink" title="final、finally、finalize 区别？"></a>final、finally、finalize 区别？</h2><ol><li>final可以修饰类、变量、方法，修饰类表示该类不能被继承、修饰方法表示该方法不能被重写、<br>修饰变量表示该变量是一个常量不能被重新赋值。</li><li>finally一般作用在try-catch代码块中，在处理异常的时候，通常我们将一定要执行的代码方法<br>finally代码块中，表示不管是否出现异常，该代码块都会执行，一般用来存放一些关闭资源的代<br>码。</li><li>finalize是一个方法，属于Object类的一个方法，而Object类是所有类的父类，Java 中允许使用<br>finalize()方法在垃圾收集器将对象从内存中清除出去之前做必要的清理工作。</li></ol>]]></content>
<tags>
<tag> java </tag>
</tags>
</entry>
<entry>
<title>java web</title>
<link href="2021/06/18/java-web/"/>
<url>2021/06/18/java-web/</url>
<content type="html"><![CDATA[<h1 id="java-Web"><a href="#java-Web" class="headerlink" title="java Web"></a>java Web</h1><p><strong>1 JSP 和 servlet 有什么区别？</strong></p><p>JSP 是 servlet 技术的扩展，本质上就是 servlet 的简易方式。servlet 和 JSP 最主要的不同点在<br>于，servlet 的应用逻辑是在 Java 文件中，并且完全从表示层中的 html 里分离开来，而 JSP 的情况<br>是 Java 和 html 可以组合成一个扩展名为 JSP 的文件。JSP 侧重于视图，servlet 主要用于控制逻<br>辑。</p><p><strong>2 JSP 有哪些内置对象？作用分别是什么？</strong></p><p>JSP 有 9 大内置对象：<br>request：封装客户端的请求，其中包含来自 get 或 post 请求的参数；<br>response：封装服务器对客户端的响应；<br>pageContext：通过该对象可以获取其他对象；<br>session：封装用户会话的对象；<br>application：封装服务器运行环境的对象；<br>out：输出服务器响应的输出流对象；<br>config：Web 应用的配置对象；<br>page：JSP 页面本身（相当于 Java 程序中的 this）；<br>exception：封装页面抛出异常的对象。</p><p><strong>3 JSP 的 4 种作用域？</strong></p><p>page：代表与一个页面相关的对象和属性。</p><p>request：代表与客户端发出的一个请求相关的对象和属性。一个请求可能跨越多个页面，涉及多个 Web 组件；需要在页面显示的临时数据可以置于此作用域。</p><p>session：代表与某个用户与服务器建立的一次会话相关的对象和属性。跟某个用户相关的数据应该放在<br>用户自己的 session 中。</p><p>application：代表与整个 Web 应用程序相关的对象和属性，它实质上是跨越整个 Web 应用程序，包括<br>多个页面、请求和会话的一个全局作用域。</p><p> <strong>4 session 和 cookie 有什么区别？</strong></p><p>存储位置不同：session 存储在服务器端；cookie 存储在浏览器端。<br>安全性不同：cookie 安全性一般，在浏览器存储，可以被伪造和修改。<br>容量和个数限制：cookie 有容量限制，每个站点下的 cookie 也有个数限制。<br>存储的多样性：session 可以存储在 Redis 中、数据库中、应用程序中；而 cookie 只能存储在浏览器<br>中。</p><p> <strong>5 session 的工作原理？</strong></p><p>session 的工作原理是客户端登录完成之后，服务器会创建对应的 session，session 创建完之后，会把<br>session 的 id 发送给客户端，客户端再存储到浏览器中。这样客户端每次访问服务器时，都会带着<br>sessionid，服务器拿到 sessionid 之后，在内存找到与之对应的 session 这样就可以正常工作了。</p><p><strong>6 如果客户端禁止 cookie 能实现 session 还能用吗？</strong></p><p>可以用，session 只是依赖 cookie 存储 sessionid，如果 cookie 被禁用了，可以使用 url 中添加<br>sessionid 的方式保证 session 能正常使用。</p>]]></content>
<tags>
<tag> java </tag>
</tags>
</entry>
<entry>
<title>ssm</title>
<link href="2021/06/16/ssm/"/>
<url>2021/06/16/ssm/</url>
<content type="html"><![CDATA[<h3 id="SSM框架整合"><a href="#SSM框架整合" class="headerlink" title="SSM框架整合"></a>SSM框架整合</h3><p>Spring + Spring MVC + MyBatis</p><p>Spring MVC 负责实现 MVC 设计模式，MyBatis 负责数据持久层，Spring 负责管理 Spring MVC 和 MyBatis 相关对象的创建和依赖注入。</p><h3 id="创建-Maven-工程"><a href="#创建-Maven-工程" class="headerlink" title="创建 Maven 工程"></a>创建 Maven 工程</h3><p>pom.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token comment" spellcheck="true"><!--spring--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.springframework<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>spring-webmvc<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>5.2.15.RELEASE<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--spring jdbc--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.springframework<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>spring-jdbc<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>4.3.30.RELEASE<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--aop--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.springframework<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>spring-aop<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>5.2.15.RELEASE<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.springframework<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>spring-aspects<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>5.2.15.RELEASE<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--mybatis--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.mybatis<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>mybatis<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>3.5.2<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--spring整合mybatis--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.mybatis<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>mybatis-spring<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>2.0.6<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--mysql驱动--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>mysql<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>mysql-connector-java<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>8.0.25<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--数据库连接ci--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>com.mchange<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>c3p0<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>0.9.5.2<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--JSTL标准标签库--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>jstl<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>jstl<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>1.2<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--servlet--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>javax.servlet<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>javax.servlet-api<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>3.1.0<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.projectlombok<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>lombok<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>1.18.6<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>scope</span><span class="token punctuation">></span></span>provided<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>scope</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>junit<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>junit<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>4.11<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>scope</span><span class="token punctuation">></span></span>test<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>scope</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span></code></pre><p>web.xml 中配置 SpringMVC、Spring、字符编码过滤器、加载静态资源。</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>web-app</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>display-name</span><span class="token punctuation">></span></span>Archetype Created Web Application<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>display-name</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--启动spring--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>context-param</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>param-name</span><span class="token punctuation">></span></span>contextConfigLocation<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>param-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>param-value</span><span class="token punctuation">></span></span>classpath:spring.xml<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>param-value</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>context-param</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>listener</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>listener-class</span><span class="token punctuation">></span></span>org.springframework.web.context.ContextLoaderListener<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>listener-class</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>listener</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--Spring Mvc--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-name</span><span class="token punctuation">></span></span>dispatcherServlet<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-class</span><span class="token punctuation">></span></span>org.springframework.web.servlet.DispatcherServlet<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-class</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>init-param</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>param-name</span><span class="token punctuation">></span></span>contextConfigLocation<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>param-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>param-value</span><span class="token punctuation">></span></span>classpath:springmvc.xml<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>param-value</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>init-param</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-name</span><span class="token punctuation">></span></span>dispatcherServlet<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>url-pattern</span><span class="token punctuation">></span></span>/<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>url-pattern</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--字符编码过滤器--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter-name</span><span class="token punctuation">></span></span>CharacterEncodingFilter<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter-class</span><span class="token punctuation">></span></span>org.springframework.web.filter.CharacterEncodingFilter<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter-class</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>init-param</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>param-name</span><span class="token punctuation">></span></span>encoding<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>param-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>param-value</span><span class="token punctuation">></span></span>UTF-8<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>param-value</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>init-param</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter-name</span><span class="token punctuation">></span></span>CharacterEncodingFilter<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>url-pattern</span><span class="token punctuation">></span></span>/*<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>url-pattern</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter-mapping</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--加载静态资源--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-name</span><span class="token punctuation">></span></span>default<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>url-pattern</span><span class="token punctuation">></span></span>*.js<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>url-pattern</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-name</span><span class="token punctuation">></span></span>default<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>url-pattern</span><span class="token punctuation">></span></span>*.css<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>url-pattern</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-name</span><span class="token punctuation">></span></span>default<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>url-pattern</span><span class="token punctuation">></span></span>*.jpg<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>url-pattern</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-mapping</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>web-app</span><span class="token punctuation">></span></span></code></pre><p>在 spring.xml 中配置 MyBatis 和 Spring 的整合。</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>beans</span> <span class="token attr-name">xmlns</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>xsi</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.w3.org/2001/XMLSchema-instance<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>context</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/context<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>p</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/p<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xsi:</span>schemaLocation</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--整合mybatis--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>dataSource<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.mchange.v2.c3p0.ComboPooledDataSource<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>user<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>root<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>password<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>123456<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>jdbcUrl<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>jdbc:mysql://localhost:3306/ssm?useUnicode<span class="token punctuation">=</span>true&amp;characterEncoding<span class="token punctuation">=</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>driverClass<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.mysql.cj.jdbc.Driver<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>initialPoolSize<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>5<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>maxPoolSize<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>10<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!--配置SqlSessionFactory--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>SqlSessionFactory<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>org.mybatis.spring.SqlSessionFactoryBean<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 注入数据库连接池 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>dataSource<span class="token punctuation">"</span></span> <span class="token attr-name">ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>dataSource<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token comment" spellcheck="true"><!-- 扫描sql配置文件:mapper需要的xml文件 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>mapperLocations<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>classpath:com/aynu/mapper/*.xml<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>configLocation<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>classpath:config.xml<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 配置扫描Dao接口包，动态实现Dao接口，注入到spring容器中 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>org.mybatis.spring.mapper.MapperScannerConfigurer<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 给出需要扫描Dao接口包 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>basePackage<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.aynu.mapper<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>beans</span><span class="token punctuation">></span></span></code></pre><p>config.xml 配置一些 MyBatis 辅助信息，比如打印 SQL 等。</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token doctype"><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>configuration</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>settings</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 打印SQL--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>setting</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>logImpl<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>STDOUT_LOGGING<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>settings</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>typeAliases</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 指定一个包名，MyBatis会在包名下搜索需要的JavaBean--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>package</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.aynu.entity<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>typeAliases</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>configuration</span><span class="token punctuation">></span></span></code></pre><p>配置 springmvc.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>beans</span> <span class="token attr-name">xmlns</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>xsi</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.w3.org/2001/XMLSchema-instance<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>context</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/context<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>mvc</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/mvc<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xsi:</span>schemaLocation</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 启动注解驱动 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">mvc:</span>annotation-driven</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">mvc:</span>annotation-driven</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 扫描业务代码 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">context:</span>component-scan</span> <span class="token attr-name">base-package</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.aynu<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">context:</span>component-scan</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 配置视图解析器 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>org.springframework.web.servlet.view.InternalResourceViewResolver<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>prefix<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>/<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>suffix<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>.jsp<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>beans</span><span class="token punctuation">></span></span></code></pre><p>实体类User</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Data</span><span class="token annotation punctuation">@AllArgsConstructor</span><span class="token annotation punctuation">@NoArgsConstructor</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">User</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">long</span> id<span class="token punctuation">;</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span> <span class="token keyword">private</span> String password<span class="token punctuation">;</span> <span class="token keyword">private</span> <span class="token keyword">double</span> score<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>UserRepository</p><pre class=" language-java"><code class="language-java"><span class="token keyword">public</span> <span class="token keyword">interface</span> <span class="token class-name">UserRepository</span> <span class="token punctuation">{</span> List<span class="token operator"><</span>User<span class="token operator">></span> <span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>UserRepository.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8" ?></span><span class="token doctype"><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>mapper</span> <span class="token attr-name">namespace</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.aynu.mapper.UserRepository<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>findAll<span class="token punctuation">"</span></span> <span class="token attr-name">resultType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>User<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> select * from user <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>select</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>mapper</span><span class="token punctuation">></span></span></code></pre><p>UserService</p><pre class=" language-java"><code class="language-java"><span class="token keyword">public</span> <span class="token keyword">interface</span> <span class="token class-name">UserService</span> <span class="token punctuation">{</span> List<span class="token operator"><</span>User<span class="token operator">></span> <span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>UserServiceImpl</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Service</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">UserServiceImpl</span> <span class="token keyword">implements</span> <span class="token class-name">UserService</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Autowired</span> <span class="token keyword">private</span> UserRepository userRepository<span class="token punctuation">;</span> <span class="token annotation punctuation">@Override</span> <span class="token annotation punctuation">@Transactional</span><span class="token punctuation">(</span>rollbackFor <span class="token operator">=</span> Exception<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">)</span> <span class="token keyword">public</span> List<span class="token operator"><</span>User<span class="token operator">></span> <span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">return</span> userRepository<span class="token punctuation">.</span><span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>UserHandler</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Controller</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/user"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">UserHandler</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Autowired</span> <span class="token keyword">private</span> UserService userService<span class="token punctuation">;</span> <span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/findAll"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> ModelAndView <span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> modelAndView<span class="token punctuation">.</span><span class="token function">setViewName</span><span class="token punctuation">(</span><span class="token string">"index"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> modelAndView<span class="token punctuation">.</span><span class="token function">addObject</span><span class="token punctuation">(</span><span class="token string">"list"</span><span class="token punctuation">,</span>userService<span class="token punctuation">.</span><span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre>]]></content>
<tags>
<tag> ssm </tag>
</tags>
</entry>
<entry>
<title>java反射原理</title>
<link href="2021/06/15/java-fan-she-yuan-li/"/>
<url>2021/06/15/java-fan-she-yuan-li/</url>
<content type="html"><![CDATA[<h2 id="Java反射"><a href="#Java反射" class="headerlink" title="Java反射"></a>Java反射</h2><p>在程序运行期间动态创建对象，编写代码/编译的过程，不需要知道创建的是哪个对象，只有在运行期间才知道要创建的对象是谁，动态获取类的信息，从而创建对象。</p><p><strong>暴力反射</strong> setAccessible(true),反射可以对private强行赋值</p><p>tips:在Javabean中，加上@Component 注入到IOC中</p><h2 id="注解"><a href="#注解" class="headerlink" title="注解"></a>注解</h2><p>注解是结合反射来运行的，注解相当于是一个标识，不作具体的操作，具体操作是由反射来完成的。</p><h2 id="synchronized锁啥"><a href="#synchronized锁啥" class="headerlink" title="synchronized锁啥"></a>synchronized锁啥</h2><ol><li>修饰静态方法时 锁类本身</li><li>修饰非静态方法时 谁使用锁谁</li><li>修饰代码块时 传谁锁谁</li></ol><p>java代码执行顺序</p><p>父类静态字段->父类静态代码块->子类静态字段->子类静态代码块->父类成员变量和非静态块(顺序加载)->父类构造函数->子类成员变量和非静态块(顺序加载)->子类构造函数</p><h2 id="事务"><a href="#事务" class="headerlink" title="事务"></a>事务</h2><p>百度百科中解释：指作为单个逻辑工作单元执行的一系列操作，要么完全地执行，要么完全地不执行。<br>简单的说，事务就是并发控制的单位，是用户定义的一个操作序列。<br>而一个逻辑工作单元要成为事务，就必须满足ACID属性。<br>A：原子性（Atomicity）<br> 事务中的操作要么都不做，要么就全做。<br>C：一致性（Consistency）<br> 事务执行的结果必须是从数据库从一个一致性状态转换到另一个一致性状态。<br>I：隔离性（Isolation）<br> 一个事务的执行不能被其他事务干扰<br>D：持久性（Durability）<br> 一个事务一旦提交，它对数据库中数据的改变就应该是永久性的</p><h2 id="数据库索引"><a href="#数据库索引" class="headerlink" title="数据库索引"></a>数据库索引</h2><p>索引是为了提高查询速度，相当于给数据进行编号，在查找数据的时候通过编号快速找到对应数据</p><p>B+Tree</p><p>主键自带索引，乱序插入数据，会自动按照id进行升序排列，数据存储内部结构类似于链表的形式，通过指针来关联不同的数据。数据量很大，查询还是很慢。</p><p>Mysql中有一个page的概念，相当于给数据进行分页，把一部分数据存入一个page中，每个page可以存储16kb的数据，相当于给数据建立了上城目录，先找大目录，在找具体的数据，MySql给page提供了快速查找的page目录。一个page目录中也可以存储16kb的数据。</p><p>B+树索引是B+树在数据库中的一种实现，是最常见也是数据库中使用最为频繁的一种索引。B+树中的B代表平衡（balance），而不是二叉（binary），因为B+树是从最早的平衡二叉树演化而来的。先了解二叉查找树、平衡二叉树（AVLTree）和平衡多路查找树（B-Tree），B+树即由这些树逐步优化而来。</p><p>为什么要用B+树做索引</p><pre class=" language-yml"><code class="language-yml">1) B+树是一种排序好的数据结构。2)与普通的二叉树相比，B+树只在叶子节点做存储，在同样的内存下，B+树叶子能够存储更多的节点数量,遍历起来更快速方便。3) B+树是一一种平衡的多叉树，能够做更少的磁盘I/O, 另外叶子节点也可以连接起来，加快遍历。</code></pre><h2 id="MySQL索引相关优化"><a href="#MySQL索引相关优化" class="headerlink" title="MySQL索引相关优化"></a>MySQL索引相关优化</h2><p>1 尽量使用主键查询: 聚簇索引上存储了全部数据, 相比普通索引查询, 减少了回表的消耗.<br>2 MySQL5.6之后引入了索引下推优化, 通过适当的使用联合索引, 减少回表判断的消耗.<br>3 若频繁查询某一列数据, 可以考虑利用覆盖索引避免回表.<br>4 联合索引将高频字段放在最左边.</p><h2 id="MySQL事务的隔离级别"><a href="#MySQL事务的隔离级别" class="headerlink" title="MySQL事务的隔离级别"></a>MySQL事务的隔离级别</h2><ol><li><p>读未提交(RU): 一个事务还没提交时, 它做的变更就能被别的事务看到.</p></li><li><p>读提交(RC): 一个事务提交之后, 它做的变更才会被其他事务看到.</p></li><li><p>可重复读(RR): 一个事务执行过程中看到的数据, 总是跟这个事务在启动时看到的数据是一致的. 当<br>然在可重复读隔离级别下, 未提交变更对其他事务也是不可见的.</p></li><li><p>串行化(S): 对于同一行记录, 读写都会加锁. 当出现读写锁冲突的时候, 后访问的事务必须等前一个<br>事务执行完成才能继续执行.</p></li></ol><h2 id="完整性约束包括哪些？"><a href="#完整性约束包括哪些？" class="headerlink" title="完整性约束包括哪些？"></a>完整性约束包括哪些？</h2><p>数据完整性(Data Integrity)是指数据的精确(Accuracy)和可靠性(Reliability)。<br>分为以下四类：<br>1、实体完整性： 规定表的每一行在表中是惟一的实体。<br>2、域完整性：是指表中的列必须满足某种特定的数据类型约束，其中约束又包括 取值范围、精度等<br>规定。3、参照完整性： 是指两个表的主关键字和外关键字的数据应一致，保证了表之间的数据的一致性，<br>防止了数据丢失或无意义的数据在数据库中扩散。<br>4、用户定义的完整性：不同的关系数据库系统根据其应用环境的不同，往往还需 要一些特殊的约束<br>条件。用户定义的完整性即是针对某个特定关系数据库的约束条件， 它反映某一具体应用必须满足的语<br>义要求。<br>与表有关的约束：包括列约束(NOT NULL（ 非空约束）)和表约束(PRIMARY KEY、foreign key、<br>check、UNIQUE) </p>]]></content>
<tags>
<tag> java </tag>
</tags>
</entry>
<entry>
<title>linux操作手册</title>
<link href="2021/06/10/linux-cao-zuo-shou-ce/"/>
<url>2021/06/10/linux-cao-zuo-shou-ce/</url>
<content type="html"><![CDATA[<h1 id="关机-重启-注销"><a href="#关机-重启-注销" class="headerlink" title="关机/重启/注销"></a>关机/重启/注销</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>shutdown -h now</td><td>即刻关机</td></tr><tr><td>shutdown -h 10</td><td>10分钟后关机</td></tr><tr><td>shutdown -h 11:00</td><td>11：00关机</td></tr><tr><td>shutdown -h +10</td><td>预定时间关机（10分钟后）</td></tr><tr><td>shutdown -c</td><td>取消指定时间关机</td></tr><tr><td>shutdown -r now</td><td>重启</td></tr><tr><td>shutdown -r 10</td><td>10分钟之后重启</td></tr><tr><td>shutdown -r 11:00</td><td>定时重启</td></tr><tr><td>reboot</td><td>重启</td></tr><tr><td>init 6</td><td>重启</td></tr><tr><td>init 0</td><td>⽴刻关机</td></tr><tr><td>telinit 0</td><td>关机</td></tr><tr><td>poweroff</td><td>⽴刻关机</td></tr><tr><td>halt</td><td>关机</td></tr><tr><td>sync</td><td>buff数据同步到磁盘</td></tr><tr><td>logout</td><td>退出登录Shell</td></tr></tbody></table><h1 id="系统信息和性能查看"><a href="#系统信息和性能查看" class="headerlink" title="系统信息和性能查看"></a>系统信息和性能查看</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>uname -a</td><td>查看内核/OS/CPU信息</td></tr><tr><td>uname -r</td><td>查看内核版本</td></tr><tr><td>uname -m</td><td>查看处理器架构</td></tr><tr><td>arch</td><td>查看处理器架构</td></tr><tr><td>hostname</td><td>查看计算机名</td></tr><tr><td>who</td><td>显示当前登录系统的⽤户</td></tr><tr><td>who am i</td><td>显示登录时的⽤户名</td></tr><tr><td>whoami</td><td>显示当前⽤户名</td></tr><tr><td>cat /proc/version</td><td>查看linux版本信息</td></tr><tr><td>cat /proc/cpuinfo</td><td>查看CPU信息</td></tr><tr><td>cat /proc/interrupts</td><td>查看中断</td></tr><tr><td>cat /proc/loadavg</td><td>查看系统负载</td></tr><tr><td>uptime</td><td>查看系统运⾏时间、⽤户数、负载</td></tr><tr><td>env</td><td>查看系统的环境变量</td></tr><tr><td>lsusb -tv</td><td>查看系统USB设备信息</td></tr><tr><td>lspci -tv</td><td>查看系统PCI设备信息</td></tr><tr><td>lsmod</td><td>查看已加载的系统模块</td></tr><tr><td>grep MemTotal /proc/meminfo</td><td>查看内存总量</td></tr><tr><td>grep MemFree /proc/meminfo</td><td>查看空闲内存量</td></tr><tr><td>free -m</td><td>查看内存⽤量和交换区⽤量</td></tr><tr><td>date</td><td>显示系统⽇期时间</td></tr><tr><td>cal 2021</td><td>显示2021⽇历表</td></tr><tr><td>top</td><td>动态显示cpu/内存/进程等情况</td></tr><tr><td>vmstat 1 20</td><td>每1秒采⼀次系统状态，采20次</td></tr><tr><td>iostat</td><td>查看io读写/cpu使⽤情况</td></tr><tr><td>查看io读写/cpu使⽤情况</td><td>查询cpu使⽤情况（1秒⼀次，共10次）</td></tr><tr><td>sar -d 1 10</td><td>查询磁盘性能</td></tr></tbody></table><h1 id="磁盘和分区"><a href="#磁盘和分区" class="headerlink" title="磁盘和分区"></a>磁盘和分区</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>fdisk -l</td><td>查看所有磁盘分区</td></tr><tr><td>swapon -s</td><td>查看所有交换分区</td></tr><tr><td>df -h</td><td>查看磁盘使⽤情况及挂载点</td></tr><tr><td>df -hl</td><td>同上</td></tr><tr><td>du -sh /dir</td><td>查看指定某个⽬录的⼤⼩</td></tr><tr><td>du -sk * | sort -rn</td><td>从⾼到低依次显示⽂件和⽬录⼤⼩</td></tr><tr><td>mount /dev/hda2 /mnt/hda2</td><td>挂载hda2盘</td></tr><tr><td>mount -t ntfs /dev/sdc1 /mnt/usbhd1</td><td>指定⽂件系统类型挂载（如ntfs）</td></tr><tr><td>mount -o loop xxx.iso /mnt/cdrom</td><td>挂 载 iso ⽂ 件</td></tr><tr><td>umount -v /dev/sda1</td><td>通过设备名卸载</td></tr><tr><td>umount -v /mnt/mymnt</td><td>通过挂载点卸载</td></tr><tr><td>fuser -km /mnt/hda1</td><td>强制卸载(慎⽤)</td></tr></tbody></table><h1 id="⽤户和⽤户组"><a href="#⽤户和⽤户组" class="headerlink" title="⽤户和⽤户组"></a>⽤户和⽤户组</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>useradd codesheep</td><td>创建⽤户</td></tr><tr><td>userdel -r codesheep</td><td>删除⽤户</td></tr><tr><td>usermod -g group_name user_name</td><td>修改⽤户的组</td></tr><tr><td>usermod -aG group_name user_name</td><td>将⽤户添加到组</td></tr><tr><td>usermod -s /bin/ksh -d /home/codepig –g dev codesheep</td><td>修改⽤户codesheep的登录Shell、主⽬录以及⽤户组</td></tr><tr><td>groups test</td><td>查看test⽤户所在的组</td></tr><tr><td>groupadd group_name</td><td>创建⽤户组</td></tr><tr><td>groupdel group_name</td><td>删除⽤户组</td></tr><tr><td>groupmod -n new_name old_name</td><td>重命名⽤户组</td></tr><tr><td>su - user_name</td><td>su - user_name</td></tr><tr><td>passwd</td><td>修改⼝令</td></tr><tr><td>passwd codesheep</td><td>修改某⽤户的⼝令</td></tr><tr><td>w</td><td>查看活动⽤户</td></tr><tr><td>id codesheep</td><td>查看指定⽤户codesheep信息</td></tr><tr><td>last</td><td>查看⽤户登录⽇志</td></tr><tr><td>crontab -l</td><td>查看当前⽤户的计划任务</td></tr><tr><td>cut -d: -f1 /etc/passwd</td><td>查看系统所有⽤户</td></tr><tr><td>cut -d: -f1 /etc/group</td><td>查看系统所有组</td></tr></tbody></table><h1 id="⽹络和进程管理"><a href="#⽹络和进程管理" class="headerlink" title="⽹络和进程管理"></a>⽹络和进程管理</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>ifconfig</td><td>查看⽹络接⼝属性</td></tr><tr><td>ifconfig eth0</td><td>查看某⽹卡的配置</td></tr><tr><td>route -n</td><td>查看路由表</td></tr><tr><td>netstat -lntp</td><td>查看所有监听端⼝</td></tr><tr><td>netstat -antp</td><td>查看已经建⽴的TCP连接</td></tr><tr><td>netstat -lutp</td><td>查看TCP/UDP的状态信息</td></tr><tr><td>ifup eth0</td><td>启⽤eth0⽹络设备</td></tr><tr><td>ifdown eth0</td><td>禁⽤eth0⽹络设备</td></tr><tr><td>iptables -L</td><td>查看iptables规则</td></tr><tr><td>ifconfig eth0 192.168.1.1 netmask 255.255.255.0</td><td>配置ip地址</td></tr><tr><td>dhclient eth0</td><td>以dhcp模式启⽤eth0</td></tr><tr><td>route add -net 0/0 gw Gateway_IP</td><td>配置默认⽹关</td></tr><tr><td>route add -net 192.168.0.0 netmask 255.255.0.0 gw 192.168.1.1</td><td>配置静态路由到达⽹络’192.168.0.0/16’</td></tr><tr><td>route del 0/0 gw Gateway_IP</td><td>删除静态路由</td></tr><tr><td>hostname</td><td>查看主机名</td></tr><tr><td>host <a href="http://www.baidu.com/">www.baidu.com</a></td><td>解析主机名</td></tr><tr><td>nslookup <a href="http://www.baidu.com/">www.baidu.com</a></td><td>查询DNS记录，查看域名解析是否正常</td></tr><tr><td>ps -ef</td><td>查看所有进程</td></tr><tr><td>ps -ef | grep codesheep</td><td>过滤出你需要的进程</td></tr><tr><td>kill -s name</td><td>kill指定名称的进程</td></tr><tr><td>kill -s pid</td><td>kill指定pid的进程</td></tr><tr><td>top</td><td>实时显示进程状态</td></tr><tr><td>vmstat 1 20</td><td>每1秒采⼀次系统状态，采20次</td></tr><tr><td>iostat</td><td>iostat</td></tr><tr><td>sar -u 1 10</td><td>查询cpu使⽤情况（1秒⼀次，共10次）</td></tr><tr><td>sar -d 1 10</td><td>查询磁盘性能</td></tr></tbody></table><h1 id="常⻅系统服务命令"><a href="#常⻅系统服务命令" class="headerlink" title="常⻅系统服务命令"></a>常⻅系统服务命令</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>chkconfig –list</td><td>列出系统服务</td></tr><tr><td>service <服务名> status</td><td>查看某个服务</td></tr><tr><td>service <服务名> start</td><td>启动某个服务</td></tr><tr><td>service <服务名> stop</td><td>终⽌某个服务</td></tr><tr><td>service <服务名> restart</td><td>重启某个服务</td></tr><tr><td>systemctl status <服务名></td><td>查看某个服务</td></tr><tr><td>systemctl start <服务名></td><td>启动某个服务</td></tr><tr><td>systemctl stop <服务名></td><td>终⽌某个服务</td></tr><tr><td>systemctl restart <服务名></td><td>重启某个服务</td></tr><tr><td>systemctl enable <服务名></td><td>关闭⾃启动</td></tr><tr><td>systemctl disable <服务名></td><td>关闭⾃启动</td></tr></tbody></table><h1 id="⽂件和⽬录操作"><a href="#⽂件和⽬录操作" class="headerlink" title="⽂件和⽬录操作"></a>⽂件和⽬录操作</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>cd <⽬录名></td><td>进⼊某个⽬录</td></tr><tr><td>cd ..</td><td>回上级⽬录</td></tr><tr><td>cd ../..</td><td>回上两级⽬录</td></tr><tr><td>cd</td><td>进个⼈主⽬录</td></tr><tr><td>cd -</td><td>回上⼀步所在⽬录</td></tr><tr><td>pwd</td><td>显示当前路径</td></tr><tr><td>ls</td><td>查看⽂件⽬录列表</td></tr><tr><td>ls -F</td><td>查看⽬录中内容（显示是⽂件还是⽬录）</td></tr><tr><td>ls -l</td><td>查看⽂件和⽬录的详情列表</td></tr><tr><td>ls -a</td><td>查看隐藏⽂件</td></tr><tr><td>ls -lh</td><td>查看⽂件和⽬录的详情列表（增强⽂件⼤⼩易读性）</td></tr><tr><td>ls -lSr</td><td>查看⽂件和⽬录列表（以⽂件⼤⼩升序查看）</td></tr><tr><td>tree</td><td>查看⽂件和⽬录的树形结构</td></tr><tr><td>mkdir <⽬录名></td><td>创建⽬录</td></tr><tr><td>mkdir dir1 dir2</td><td>同时创建两个⽬录</td></tr><tr><td>mkdir -p /tmp/dir1/dir2</td><td>创建⽬录树</td></tr><tr><td>rm -f file1</td><td>删除’file1’⽂件</td></tr><tr><td>rmdir dir1</td><td>删除’dir1’⽬录</td></tr><tr><td>rm -rf dir1</td><td>删除’dir1’⽬录和其内容</td></tr><tr><td>rm -rf dir1 dir2</td><td>同时删除两个⽬录及其内容</td></tr><tr><td>mv old_dir new_dir</td><td>重命名/移动⽬录</td></tr><tr><td>cp file1 file2</td><td>复制⽂件</td></tr><tr><td>cp dir/* .</td><td>复制某⽬录下的所有⽂件⾄当前⽬录</td></tr><tr><td>cp -a dir1 dir2</td><td>复制⽬录</td></tr><tr><td>cp -a /tmp/dir1 .</td><td>复制⼀个⽬录⾄当前⽬录</td></tr><tr><td>ln -s file1 link1</td><td>创建指向⽂件/⽬录的软链接</td></tr><tr><td>ln file1 lnk1</td><td>创建指向⽂件/⽬录的物理链接</td></tr><tr><td>find / -name file1</td><td>从跟⽬录开始搜索⽂件/⽬录</td></tr><tr><td>find / -user user1</td><td>搜索⽤户user1的⽂件/⽬录</td></tr><tr><td>find /dir -name *.bin</td><td>在⽬录/dir中搜带有.bin后缀的⽂件</td></tr><tr><td>locate <关键词></td><td>快速定位⽂件</td></tr><tr><td>locate *.mp4</td><td>寻找.mp4结尾的⽂件</td></tr><tr><td>whereis <关键词></td><td>显示某⼆进制⽂件/可执⾏⽂件的路径</td></tr><tr><td>which <关键词></td><td>查找系统⽬录下某的⼆进制⽂件</td></tr><tr><td>chmod ugo+rwx dir1</td><td>设置⽬录所有者(u)、群组(g)及其他⼈(o)的读（r）写(w)执⾏(x)权限</td></tr><tr><td>chmod go-rwx dir1</td><td>移除群组(g)与其他⼈(o)对⽬录的读写执⾏权限</td></tr><tr><td>chown user1 file1</td><td>改变⽂件的所有者属性</td></tr><tr><td>chown -R user1 dir1</td><td>改变⽬录的所有者属性</td></tr><tr><td>chgrp group1 file1</td><td>改变⽂件群组</td></tr><tr><td>chown user1:group1 file1</td><td>改变⽂件的所有⼈和群组</td></tr></tbody></table><h1 id="⽂件查看和处理"><a href="#⽂件查看和处理" class="headerlink" title="⽂件查看和处理"></a>⽂件查看和处理</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>cat file1</td><td>查看⽂件内容</td></tr><tr><td>cat -n file1</td><td>查看内容并标示⾏数</td></tr><tr><td>tac file1</td><td>从最后⼀⾏开始反看⽂件内容</td></tr><tr><td>more file1</td><td>more file1</td></tr><tr><td>less file1</td><td>类似more命令，但允许反向操作</td></tr><tr><td>head -2 file1</td><td>查看⽂件前两⾏</td></tr><tr><td>tail -2 file1</td><td>查看⽂件后两⾏</td></tr><tr><td>tail -f /log/msg</td><td>实时查看添加到⽂件中的内容</td></tr><tr><td>grep codesheep hello.txt</td><td>在⽂件hello.txt中查找关键词codesheep</td></tr><tr><td>grep ^sheep hello.txt</td><td>在⽂件hello.txt中查找以sheep开头的内容</td></tr><tr><td>grep [0-9] hello.txt</td><td>选择hello.txt⽂件中所有包含数字的⾏</td></tr><tr><td>sed ‘s/s1/s2/g’ hello.txt</td><td>将hello.txt⽂件中的s1替换成s2</td></tr><tr><td>sed ‘/^$/d’ hello.txt</td><td>从hello.txt⽂件中删除所有空⽩⾏</td></tr><tr><td>sed ‘/ *#/d; /^$/d’ hello.txt</td><td>从hello.txt⽂件中删除所有注释和空⽩⾏</td></tr><tr><td>sed -e ‘1d’ hello.txt</td><td>从⽂件hello.txt 中排除第⼀⾏</td></tr><tr><td>sed -n ‘/s1/p’ hello.txt</td><td>查看只包含关键词”s1”的⾏</td></tr><tr><td>sed -e ‘s/ *$//‘ hello.txt</td><td>删除每⼀⾏最后的空⽩字符</td></tr><tr><td>sed -e ‘s/s1//g’ hello.txt</td><td>从⽂档中只删除词汇s1并保留剩余全部</td></tr><tr><td>sed -n ‘1,5p;5q’ hello.txt</td><td>查看从第⼀⾏到第5⾏内容</td></tr><tr><td>sed -n ‘5p;5q’ hello.txt</td><td>查看第5⾏</td></tr><tr><td>paste file1 file2</td><td>合并两个⽂件或两栏的内容</td></tr><tr><td>paste -d ‘+’ file1 file2</td><td>合并两个⽂件或两栏的内容，中间⽤”+”区分</td></tr><tr><td>sort file1 file2</td><td>排序两个⽂件的内容</td></tr><tr><td>comm -1 file1 file2</td><td>⽐较两个⽂件的内容(去除’file1’所含内容)</td></tr><tr><td>comm -2 file1 file2</td><td>⽐较两个⽂件的内容(去除’file2’所含内容</td></tr><tr><td>comm -3 file1 file2</td><td>⽐较两个⽂件的内容(去除两⽂件共有部分)</td></tr></tbody></table><h1 id="打包和解压"><a href="#打包和解压" class="headerlink" title="打包和解压"></a>打包和解压</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>zip xxx.zip file</td><td>压缩⾄zip包</td></tr><tr><td>zip -r xxx.zip file1 file2 dir1</td><td>将多个⽂件+⽬录压成zip包</td></tr><tr><td>unzip xxx.zip</td><td>解压zip包</td></tr><tr><td>tar -cvf xxx.tar file</td><td>创建⾮压缩tar包</td></tr><tr><td>tar -cvf xxx.tar file1 file2 dir1</td><td>将多个⽂件+⽬录打tar包</td></tr><tr><td>tar -tf xxx.tar</td><td>查看tar包的内容</td></tr><tr><td>tar -xvf xxx.tar</td><td>解压tar包</td></tr><tr><td>tar -xvf xxx.tar -C /dir</td><td>将tar包解压⾄指定⽬录</td></tr><tr><td>tar -cvfj xxx.tar.bz2 dir</td><td>创建bz2压缩包</td></tr><tr><td>tar -jxvf xxx.tar.bz2</td><td>解压bz2压缩包</td></tr><tr><td>tar -cvfz xxx.tar.gz dir</td><td>创建gzip压缩包</td></tr><tr><td>tar -zxvf xxx.tar.gz</td><td>解压gzip压缩包</td></tr><tr><td>bunzip2 xxx.bz2</td><td>解压bz2压缩包</td></tr><tr><td>bzip2 filename</td><td>压缩⽂件</td></tr><tr><td>gunzip xxx.gz</td><td>解压gzip压缩包</td></tr><tr><td>gzip filename</td><td>压缩⽂件</td></tr><tr><td>gzip -9 filename</td><td>最⼤程度压缩</td></tr></tbody></table><h1 id="RPM包管理命令"><a href="#RPM包管理命令" class="headerlink" title="RPM包管理命令"></a>RPM包管理命令</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>rpm -qa</td><td>查看已安装的rpm包</td></tr><tr><td>rpm -q pkg_name</td><td>查询某个rpm包</td></tr><tr><td>rpm -q –whatprovides xxx</td><td>显示xxx功能是由哪个包提供的</td></tr><tr><td>rpm -q –whatrequires xxx</td><td>显示xxx功能被哪个程序包依赖的</td></tr><tr><td>rpm -q –changelog xxx</td><td>显示xxx包的更改记录</td></tr><tr><td>rpm -qi pkg_name</td><td>查看⼀个包的详细信息</td></tr><tr><td>rpm -qd pkg_name</td><td>查询⼀个包所提供的⽂档</td></tr><tr><td>rpm -qc pkg_name</td><td>查看已安装rpm包提供的配置⽂件</td></tr><tr><td>rpm -ql pkg_name</td><td>查看⼀个包安装了哪些⽂件</td></tr><tr><td>rpm -qf filename</td><td>查看某个⽂件属于哪个包</td></tr><tr><td>rpm -qR pkg_name</td><td>查询包的依赖关系</td></tr><tr><td>rpm -ivh xxx.rpm</td><td>安装rpm包</td></tr><tr><td>rpm -ivh –test xxx.rpm</td><td>测试安装rpm包</td></tr><tr><td>rpm -ivh –nodeps xxx.rpm</td><td>安装rpm包时忽略依赖关系</td></tr><tr><td>rpm -e xxx</td><td>卸载程序包</td></tr><tr><td>rpm -Fvh pkg_name</td><td>升级确定已安装的rpm包</td></tr><tr><td>rpm -Uvh pkg_name</td><td>升级rpm包(若未安装则会安装)</td></tr><tr><td>rpm -V pkg_name</td><td>RPM包详细信息校验</td></tr></tbody></table><h1 id="YUM包管理命令"><a href="#YUM包管理命令" class="headerlink" title="YUM包管理命令"></a>YUM包管理命令</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>yum repolist enabled</td><td>显示可⽤的源仓库</td></tr><tr><td>yum search pkg_name</td><td>搜索软件包</td></tr><tr><td>yum install pkg_name</td><td>下载并安装软件包</td></tr><tr><td>yum install –downloadonly pkg_name</td><td>只 下 载 不 安 装</td></tr><tr><td>yum list</td><td>显示所有程序包</td></tr><tr><td>yum list installed</td><td>查看当前系统已安装包</td></tr><tr><td>yum list updates</td><td>查看可以更新的包列表</td></tr><tr><td>yum check-update</td><td>查看可升级的软件包</td></tr><tr><td>yum update</td><td>更新所有软件包</td></tr><tr><td>yum update pkg_name</td><td>升级指定软件包</td></tr><tr><td>yum deplist pkg_name</td><td>列出软件包依赖关系</td></tr><tr><td>yum remove pkg_name</td><td>删除软件包</td></tr><tr><td>yum clean all</td><td>清除缓存</td></tr><tr><td>yum clean packages</td><td>清除缓存的软件包</td></tr><tr><td>yum clean headers</td><td>清除缓存的header</td></tr></tbody></table><h1 id="DPKG包管理命令"><a href="#DPKG包管理命令" class="headerlink" title="DPKG包管理命令"></a>DPKG包管理命令</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>dpkg -c xxx.deb</td><td>列出deb包的内容</td></tr><tr><td>dpkg -i xxx.deb</td><td>安装/更新deb包</td></tr><tr><td>dpkg -r pkg_name</td><td>移除deb包</td></tr><tr><td>dpkg -P pkg_name</td><td>移除deb包(不保留配置)</td></tr><tr><td>dpkg -l</td><td>查看系统中已安装deb包</td></tr><tr><td>dpkg -l pkg_name</td><td>显示包的⼤致信息</td></tr><tr><td>dpkg -L pkg_name</td><td>查看deb包安装的⽂件</td></tr><tr><td>dpkg -s pkg_name</td><td>查看包的详细信息</td></tr><tr><td>dpkg –unpack xxx.deb</td><td>解开deb包的内容</td></tr></tbody></table><h1 id="APT软件⼯具"><a href="#APT软件⼯具" class="headerlink" title="APT软件⼯具"></a>APT软件⼯具</h1><table><thead><tr><th>常用命令</th><th>作用</th></tr></thead><tbody><tr><td>apt-cache search pkg_name</td><td>搜索程序包</td></tr><tr><td>apt-cache show pkg_name</td><td>获取包的概览信息</td></tr><tr><td>apt-get install pkg_name</td><td>安装/升级软件包</td></tr><tr><td>apt-get purge pkg_name</td><td>卸载软件（包括配置）</td></tr><tr><td>apt-get remove pkg_name</td><td>卸载软件（不包括配置）</td></tr><tr><td>apt-get update</td><td>更新包索引信息</td></tr><tr><td>apt-get upgrade</td><td>更新已安装软件包</td></tr><tr><td>apt-get clean</td><td>清理缓存</td></tr></tbody></table>]]></content>
<tags>
<tag> linux </tag>
</tags>
</entry>
<entry>
<title>jwt简述</title>
<link href="2021/06/09/jwt-jian-shu/"/>
<url>2021/06/09/jwt-jian-shu/</url>
<content type="html"><![CDATA[<h3 id="JWT是什么"><a href="#JWT是什么" class="headerlink" title="JWT是什么"></a>JWT是什么</h3><p>JSON Web Token（JWT）是一个非常轻巧的规范。这个规范允许我们使用JWT在用户和服务器之间传递安全可靠的信息。他的两大使用场景是：认证和数据交换</p><p>使用起来就是，由服务端根据规范生成一个令牌（token），并且发放给客户端。此时客户端请求服务端的时候就可以携带者令牌，以令牌来证明自己的身份信息。</p><p>作用：类似session保持登录状态 的办法，通过token来代表用户身份。</p><p>一个JWT实际上就是一个字符串，它由三部分组成，头部、载荷与签名。</p><h3 id="JWT签发与验证token"><a href="#JWT签发与验证token" class="headerlink" title="JWT签发与验证token"></a>JWT签发与验证token</h3><h4 id="pom-xml引入依赖"><a href="#pom-xml引入依赖" class="headerlink" title="pom.xml引入依赖"></a>pom.xml引入依赖</h4><pre class=" language-xml"><code class="language-xml"> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>io.jsonwebtoken<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>jjwt<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>0.9.1<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span></code></pre><h4 id="创建token"><a href="#创建token" class="headerlink" title="创建token"></a>创建token</h4><pre class=" language-java"><code class="language-java"><span class="token keyword">private</span> <span class="token keyword">long</span> time <span class="token operator">=</span> <span class="token number">1000</span><span class="token operator">*</span><span class="token number">60</span><span class="token operator">*</span><span class="token number">60</span><span class="token operator">*</span><span class="token number">24</span><span class="token punctuation">;</span><span class="token comment" spellcheck="true">//一天</span> <span class="token keyword">private</span> String signature <span class="token operator">=</span> <span class="token string">"admin"</span><span class="token punctuation">;</span> <span class="token annotation punctuation">@org</span><span class="token punctuation">.</span>junit<span class="token punctuation">.</span>jupiter<span class="token punctuation">.</span>api<span class="token punctuation">.</span>Test <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">jwt</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> JwtBuilder jwtBuilder <span class="token operator">=</span> Jwts<span class="token punctuation">.</span><span class="token function">builder</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment" spellcheck="true">//用来构建Jwt</span> String jwtToken <span class="token operator">=</span> jwtBuilder <span class="token comment" spellcheck="true">//header</span> <span class="token punctuation">.</span><span class="token function">setHeaderParam</span><span class="token punctuation">(</span><span class="token string">"typ"</span><span class="token punctuation">,</span><span class="token string">"JWT"</span><span class="token punctuation">)</span> <span class="token punctuation">.</span><span class="token function">setHeaderParam</span><span class="token punctuation">(</span><span class="token string">"alg"</span><span class="token punctuation">,</span><span class="token string">"HS256"</span><span class="token punctuation">)</span> <span class="token comment" spellcheck="true">//算法</span> <span class="token comment" spellcheck="true">//payload载荷</span> <span class="token punctuation">.</span><span class="token function">claim</span><span class="token punctuation">(</span><span class="token string">"username"</span><span class="token punctuation">,</span><span class="token string">"Tom"</span><span class="token punctuation">)</span> <span class="token punctuation">.</span><span class="token function">claim</span><span class="token punctuation">(</span><span class="token string">"role"</span><span class="token punctuation">,</span><span class="token string">"admin"</span><span class="token punctuation">)</span> <span class="token punctuation">.</span><span class="token function">setSubject</span><span class="token punctuation">(</span><span class="token string">"admin-test"</span><span class="token punctuation">)</span><span class="token comment" spellcheck="true">//主题</span> <span class="token punctuation">.</span><span class="token function">setExpiration</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">Date</span><span class="token punctuation">(</span>System<span class="token punctuation">.</span><span class="token function">currentTimeMillis</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">+</span>time<span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token comment" spellcheck="true">//存活一天</span> <span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>UUID<span class="token punctuation">.</span><span class="token function">randomUUID</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token comment" spellcheck="true">//signature 签名</span> <span class="token punctuation">.</span><span class="token function">signWith</span><span class="token punctuation">(</span>HS256<span class="token punctuation">,</span>signature<span class="token punctuation">)</span> <span class="token punctuation">.</span><span class="token function">compact</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>jwtToken<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span></code></pre><p>生成结果（三部分用 . 分割）</p><pre class=" language-java"><code class="language-java">eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9<span class="token punctuation">.</span>eyJ1c2VybmFtZSI6IlRvbSIsInJvbGUiOiJhZG1pbiIsInN1YiI6ImFkbWluLXRlc3QiLCJleHAiOjE2MjMzMDg2MDQsImp0aSI6ImZkOGVjYzdlLWUwOTUtNDBjZi1iNTkwLTNiYzBkZjUxZDcxOCJ9<span class="token punctuation">.</span>expEbWQfiNBL1VDub2Ed6w2b2vwE6SHFSoubqR1M_KE</code></pre><h4 id="解析token"><a href="#解析token" class="headerlink" title="解析token"></a>解析token</h4><pre class=" language-Java"><code class="language-Java"> @org.junit.jupiter.api.Test public void parse(){ /*解密*/ String token = "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VybmFtZSI6IlRvbSIsInJvbGUiOiJhZG1pbiIsInN1YiI6ImFkbWluLXRlc3QiLCJleHAiOjE2MjMzMDg2MDQsImp0aSI6ImZkOGVjYzdlLWUwOTUtNDBjZi1iNTkwLTNiYzBkZjUxZDcxOCJ9.expEbWQfiNBL1VDub2Ed6w2b2vwE6SHFSoubqR1M_KE"; JwtParser jwtParser = Jwts.parser(); Jws<Claims> claimsJws = jwtParser.setSigningKey(signature).parseClaimsJws(token); Claims claims = claimsJws.getBody(); System.out.println(claims); System.out.println(claims.get("username")); System.out.println(claims.get("role")); System.out.println(claims.getId()); System.out.println(claims.getSubject()); //签名 System.out.println(claims.getExpiration()); //有效期 }</code></pre><p>结果</p><pre class=" language-java"><code class="language-java"><span class="token punctuation">{</span>username<span class="token operator">=</span>Tom<span class="token punctuation">,</span> role<span class="token operator">=</span>admin<span class="token punctuation">,</span> sub<span class="token operator">=</span>admin<span class="token operator">-</span>test<span class="token punctuation">,</span> exp<span class="token operator">=</span><span class="token number">1623308604</span><span class="token punctuation">,</span> jti<span class="token operator">=</span>fd8ecc7e<span class="token operator">-</span>e095<span class="token operator">-</span>40cf<span class="token operator">-</span>b590<span class="token operator">-</span>3bc0df51d718<span class="token punctuation">}</span>Tomadminfd8ecc7e<span class="token operator">-</span>e095<span class="token operator">-</span>40cf<span class="token operator">-</span>b590<span class="token operator">-</span>3bc0df51d718admin<span class="token operator">-</span>testThu Jun <span class="token number">10</span> <span class="token number">15</span><span class="token operator">:</span><span class="token number">03</span><span class="token operator">:</span><span class="token number">24</span> CST <span class="token number">2021</span></code></pre>]]></content>
<tags>
<tag> jwt </tag>
</tags>
</entry>
<entry>
<title>vue从入门到关门</title>
<link href="2021/06/08/vue-cong-ru-men-dao-guan-men/"/>
<url>2021/06/08/vue-cong-ru-men-dao-guan-men/</url>
<content type="html"><![CDATA[<h1 id="vue基础"><a href="#vue基础" class="headerlink" title="vue基础"></a>vue基础</h1><p>官方指南假设你已了解关于 HTML、CSS 和 JavaScript 的中级知识。如果你刚开始学习前端开发，将框架作为你的第一步可能不是最好的主意——掌握好基础知识再来吧！之前有其它框架的使用经验会有帮助，但这不是必需的。</p><h2 id="第一个vue程序"><a href="#第一个vue程序" class="headerlink" title="第一个vue程序"></a>第一个vue程序</h2><p>1 导入开发版本的Vue.js</p><p>2 创建实例对象，设置el属性和data属性</p><p>3 使用模板语法渲染到页面上</p><pre class=" language-xml"><code class="language-xml"> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>title</span><span class="token punctuation">></span></span>index<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>title</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> {{ message }} <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span> <span class="token punctuation">{</span> message<span class="token punctuation">:</span> <span class="token string">'Hello Vue!!'</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><h3 id="el挂载点："><a href="#el挂载点：" class="headerlink" title="el挂载点："></a>el挂载点：</h3><p>1 Vue实例范围是el命中元素及其内部的后代元素</p><p>2 支持 标签选择器 ，<strong>id</strong> ， class ,最好是id选择器</p><p>3 支持其他的双标签，不能使用HTML ，BODY，最好是div</p><h3 id="data数据对象："><a href="#data数据对象：" class="headerlink" title="data数据对象："></a>data数据对象：</h3><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> {{ message }} <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h2</span><span class="token punctuation">></span></span>{{ school.name }}{{ school.tel }}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h2</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>li</span><span class="token punctuation">></span></span>{{ citys[0] }}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>li</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>li</span><span class="token punctuation">></span></span>{{ citys }}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>li</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span> <span class="token punctuation">{</span> message<span class="token punctuation">:</span> <span class="token string">'Hello Vue!!'</span><span class="token punctuation">,</span> school<span class="token punctuation">:</span><span class="token punctuation">{</span> name <span class="token punctuation">:</span><span class="token string">'Long'</span><span class="token punctuation">,</span> tel <span class="token punctuation">:</span><span class="token string">'123456'</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> citys<span class="token punctuation">:</span><span class="token punctuation">[</span><span class="token string">"beijing"</span><span class="token punctuation">,</span><span class="token string">"shanghai"</span><span class="token punctuation">,</span><span class="token string">"senzen"</span><span class="token punctuation">]</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><h2 id="本地应用"><a href="#本地应用" class="headerlink" title="本地应用"></a>本地应用</h2><h3 id="v-text"><a href="#v-text" class="headerlink" title="v-text"></a>v-text</h3><p>设置标签内容，可使用差值表达式替换指定内容，内部支持表达式</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h2</span><span class="token punctuation">></span></span>before {{ message }} after<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h2</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h2</span> <span class="token attr-name">v-text</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>message+<span class="token punctuation">'</span>String<span class="token punctuation">'</span><span class="token punctuation">"</span></span><span class="token punctuation">></span></span>111<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h2</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h2</span> <span class="token attr-name">v-text</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>info<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h2</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span> <span class="token punctuation">{</span> message<span class="token punctuation">:</span> <span class="token string">'Hello Vue!!'</span><span class="token punctuation">,</span> info<span class="token punctuation">:</span> <span class="token string">'Info'</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> 差值表达式{{message}}</code></pre><h3 id="v-html"><a href="#v-html" class="headerlink" title="v-html"></a>v-html</h3><p>会解析html</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span> <span class="token attr-name">v-html</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>content<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span> <span class="token punctuation">{</span> content <span class="token punctuation">:</span> <span class="token string">"<a href='https://www.baidu.com/'>baidu</a>"</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><h3 id="v-on"><a href="#v-on" class="headerlink" title="v-on"></a>v-on</h3><p>为元素绑定事件 function要放在methods（方法）中</p><pre class=" language-xml"><code class="language-xml"> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">v-on:</span>click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>doLike<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>doLike<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span> <span class="token attr-name">@dblclick</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>doLike<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h2</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>dofood<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> {{food}} <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h2</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data <span class="token punctuation">:</span><span class="token punctuation">{</span> food <span class="token punctuation">:</span><span class="token string">"apple"</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span> <span class="token punctuation">{</span> doLike<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">alert</span><span class="token punctuation">(</span><span class="token string">"11111"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> dofood<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>food<span class="token operator">+</span><span class="token operator">=</span><span class="token string">"nice"</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><h3 id="计数器"><a href="#计数器" class="headerlink" title="计数器"></a>计数器</h3><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>sub<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> - <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>span</span><span class="token punctuation">></span></span>{{num}}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>span</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>add<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> + <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data <span class="token punctuation">:</span><span class="token punctuation">{</span> num <span class="token punctuation">:</span><span class="token number">1</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span> <span class="token punctuation">{</span> add<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span><span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">.</span>num<span class="token operator"><</span><span class="token number">10</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>num<span class="token operator">++</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token keyword">else</span><span class="token punctuation">{</span> <span class="token function">alert</span><span class="token punctuation">(</span><span class="token string">"max is 10"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> sub<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span><span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">.</span>num<span class="token operator">></span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>num<span class="token operator">--</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token keyword">else</span><span class="token punctuation">{</span> <span class="token function">alert</span><span class="token punctuation">(</span><span class="token string">"min is 0"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><p>tip; 方法中通过this，关键字获取data中的数据</p><h3 id="v-show"><a href="#v-show" class="headerlink" title="v-show"></a>v-show</h3><p>根据表达式的真假，切换元素的显示和隐藏（修改display值），条件最后都会解析为布尔值，数据改变之后，对应元素显示状态会同步更新</p><pre class=" language-xml"><code class="language-xml"> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>changeShow<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>changeShow<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h1</span> <span class="token attr-name">v-show</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>isShow<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>SHOW<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h1</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h1</span><span class="token punctuation">></span></span>{{age}}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h1</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h1</span> <span class="token attr-name">v-show</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>age<span class="token punctuation">></span>18<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>You have grown up!!!<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h1</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>addAge<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>addAge<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data <span class="token punctuation">:</span><span class="token punctuation">{</span> isShow <span class="token punctuation">:</span><span class="token boolean">false</span><span class="token punctuation">,</span> age<span class="token punctuation">:</span><span class="token number">16</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span> <span class="token punctuation">{</span> changeShow<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>isShow <span class="token operator">=</span> <span class="token operator">!</span><span class="token keyword">this</span><span class="token punctuation">.</span>isShow<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">,</span> addAge<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>age<span class="token operator">++</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><h3 id="v-if"><a href="#v-if" class="headerlink" title="v-if"></a>v-if</h3><p>根据表达式的真假(true or false)，切换元素的显示和隐藏（操纵dom元素，更加消耗性能）</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span> <span class="token attr-name">v-if</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>isShow<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>ShOW<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>changeShow<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>changeShow<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data <span class="token punctuation">:</span><span class="token punctuation">{</span> isShow <span class="token punctuation">:</span><span class="token boolean">false</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span> <span class="token punctuation">{</span> changeShow<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>isShow <span class="token operator">=</span> <span class="token operator">!</span><span class="token keyword">this</span><span class="token punctuation">.</span>isShow<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><h3 id="v-bind"><a href="#v-bind" class="headerlink" title="v-bind"></a>v-bind</h3><p>设置元素属性（例如 src，title，class）</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>title</span><span class="token punctuation">></span></span>index<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>title</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>style</span><span class="token punctuation">></span></span><span class="token style language-css"> <span class="token selector"><span class="token class">.active</span></span><span class="token punctuation">{</span> <span class="token property">border</span><span class="token punctuation">:</span> <span class="token number">1</span>px solid red<span class="token punctuation">;</span> <span class="token punctuation">}</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>style</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name"><span class="token namespace">v-bind:</span>src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>src<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>br</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">:src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>src<span class="token punctuation">"</span></span> <span class="token attr-name">:title</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>imgtitle+<span class="token punctuation">'</span>!!!!<span class="token punctuation">'</span><span class="token punctuation">"</span></span> <span class="token attr-name">:class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>isActive?<span class="token punctuation">'</span>active<span class="token punctuation">'</span>:<span class="token punctuation">'</span><span class="token punctuation">'</span><span class="token punctuation">"</span></span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>changeShow<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>br</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">:src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>src<span class="token punctuation">"</span></span> <span class="token attr-name">:title</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>imgtitle+<span class="token punctuation">'</span>!!!!<span class="token punctuation">'</span><span class="token punctuation">"</span></span> <span class="token attr-name">:class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>{active:isActive}<span class="token punctuation">"</span></span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>changeShow<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data <span class="token punctuation">:</span><span class="token punctuation">{</span> src<span class="token punctuation">:</span> <span class="token string">"https://gitee.com/maoshencat/imgpng/raw/master/ajax/ajax3.PNG"</span><span class="token punctuation">,</span> imgtitle<span class="token punctuation">:</span> <span class="token string">"title"</span><span class="token punctuation">,</span> isActive<span class="token punctuation">:</span> <span class="token boolean">false</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span> <span class="token punctuation">{</span> changeShow<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>isActive <span class="token operator">=</span> <span class="token operator">!</span><span class="token keyword">this</span><span class="token punctuation">.</span>isActive<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><h3 id="图片切换"><a href="#图片切换" class="headerlink" title="图片切换"></a>图片切换</h3><p>1定义图片数组 2添加图片索引 3绑定src属性 4图片切换逻辑 5显示状态切换</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">:src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>imgArr[index]<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>br</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h2</span><span class="token punctuation">></span></span>now is{{index}}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h2</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>br</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>prev<span class="token punctuation">"</span></span> <span class="token attr-name">v-show</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>index !<span class="token punctuation">=</span> 0<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>prev<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>next<span class="token punctuation">"</span></span> <span class="token attr-name">v-show</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>index < imgArr.length-1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>next<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data <span class="token punctuation">:</span><span class="token punctuation">{</span> imgArr<span class="token punctuation">:</span> <span class="token punctuation">[</span><span class="token string">"https://gitee.com/maoshencat/imgpng/raw/master/ajax/ajax3.PNG"</span><span class="token punctuation">,</span> <span class="token string">"https://gitee.com/maoshencat/imgpng/raw/master/ajax/list.PNG"</span><span class="token punctuation">,</span> <span class="token string">"https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622770617878.png"</span> <span class="token punctuation">]</span><span class="token punctuation">,</span> index<span class="token punctuation">:</span><span class="token number">0</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span> <span class="token punctuation">{</span> prev<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>index<span class="token operator">--</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">,</span> next<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>index<span class="token operator">++</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> </code></pre><h3 id="v-for"><a href="#v-for" class="headerlink" title="v-for"></a>v-for</h3><p>根据数据生成列表结构,语法是（item，index） in 数据</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>add<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>add<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>remove<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>remove<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>li</span> <span class="token attr-name">v-for</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>(item,index) in arr<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> {{ index+1 }}city:{{ item }} <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>li</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h2</span> <span class="token attr-name">v-for</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>item in fruit<span class="token punctuation">"</span></span> <span class="token attr-name">:title</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>item.name<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> {{ item.name }} <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h2</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data <span class="token punctuation">:</span><span class="token punctuation">{</span> arr<span class="token punctuation">:</span> <span class="token punctuation">[</span><span class="token string">"Beijing"</span><span class="token punctuation">,</span><span class="token string">"Shanghai"</span><span class="token punctuation">,</span><span class="token string">"Hongkong"</span><span class="token punctuation">]</span><span class="token punctuation">,</span> fruit<span class="token punctuation">:</span><span class="token punctuation">[</span> <span class="token punctuation">{</span>name<span class="token punctuation">:</span><span class="token string">"apple"</span><span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token punctuation">{</span>name<span class="token punctuation">:</span><span class="token string">"branner"</span><span class="token punctuation">}</span> <span class="token punctuation">]</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span><span class="token punctuation">{</span> add<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>fruit<span class="token punctuation">.</span><span class="token function">push</span><span class="token punctuation">(</span><span class="token punctuation">{</span>name<span class="token punctuation">:</span><span class="token string">"juzi"</span><span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> remove<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 移除最左边数据</span> <span class="token keyword">this</span><span class="token punctuation">.</span>fruit<span class="token punctuation">.</span><span class="token function">shift</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span></code></pre><h3 id="v-on补充"><a href="#v-on补充" class="headerlink" title="v-on补充"></a>v-on补充</h3><p>传递自定义参数，事件修饰符，绑定的数据会和表单元素值相关联</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h1</span><span class="token punctuation">></span></span>here<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h1</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>doLike(66,<span class="token punctuation">'</span>String<span class="token punctuation">'</span>)<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>dooooo<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- enter健触发 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text<span class="token punctuation">"</span></span> <span class="token attr-name">@keyup.enter</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>sayHi<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span><span class="token punctuation">{</span> doLike<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span>p1<span class="token punctuation">,</span>p2<span class="token punctuation">)</span><span class="token punctuation">{</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token string">"dododododoo"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token function">alert</span><span class="token punctuation">(</span>p1<span class="token operator">+</span>p2<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> sayHi<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">alert</span><span class="token punctuation">(</span><span class="token string">"do you eat?"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span></code></pre><h3 id="v-model"><a href="#v-model" class="headerlink" title="v-model"></a>v-model</h3><p>获取和设置表单元素的绑定（双向数据绑定）</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>setM<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>update<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text<span class="token punctuation">"</span></span> <span class="token attr-name">v-model</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>message<span class="token punctuation">"</span></span> <span class="token attr-name">@keyup.enter</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>getM<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h2</span><span class="token punctuation">></span></span>同步更新：{{message}}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h2</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span><span class="token punctuation">{</span> message<span class="token punctuation">:</span><span class="token string">"longlong"</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span><span class="token punctuation">{</span> getM<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">alert</span><span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">.</span>message<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> setM<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>message <span class="token operator">=</span> <span class="token string">"new msg!"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span></code></pre><h3 id="记事本"><a href="#记事本" class="headerlink" title="记事本"></a>记事本</h3><p>添加：v-for数组生成列表及结构，v-model获取用户输入，v-on.enter添加数据</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h1</span><span class="token punctuation">></span></span>记事本demo<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h1</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">autofocus</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>autofocus<span class="token punctuation">"</span></span> <span class="token attr-name">autocomplete</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>false<span class="token punctuation">"</span></span> <span class="token attr-name">placeholder</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>please key in your tip<span class="token punctuation">"</span></span> <span class="token attr-name">v-model</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>inputValue<span class="token punctuation">"</span></span> <span class="token attr-name">@keyup.enter</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>add<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- list --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>li</span> <span class="token attr-name">v-for</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>(item,index) in list<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>span</span><span class="token punctuation">></span></span>{{ index+1 }}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>span</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>label</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>remove(index)<span class="token punctuation">"</span></span> <span class="token attr-name">:title</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>del<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>{{ item }}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>label</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>li</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>footer</span> <span class="token attr-name">v-if</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>list.length !<span class="token punctuation">=</span> 0<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span>共{{list.length}}条<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>button</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>clear<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>删除所有<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>button</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>footer</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">'#app'</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span><span class="token punctuation">{</span> list<span class="token punctuation">:</span><span class="token punctuation">[</span><span class="token string">"good"</span><span class="token punctuation">,</span><span class="token string">"nice"</span><span class="token punctuation">,</span><span class="token string">"haha哈"</span><span class="token punctuation">]</span><span class="token punctuation">,</span> inputValue<span class="token punctuation">:</span><span class="token string">""</span><span class="token punctuation">,</span> del<span class="token punctuation">:</span><span class="token string">"click delete"</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span><span class="token punctuation">{</span> add<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>list<span class="token punctuation">.</span><span class="token function">push</span><span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">.</span>inputValue<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> remove<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span>index<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">alert</span><span class="token punctuation">(</span><span class="token string">"remove!"</span><span class="token operator">+</span>index<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//删除，一次删除一个</span> <span class="token keyword">this</span><span class="token punctuation">.</span>list<span class="token punctuation">.</span><span class="token function">splice</span><span class="token punctuation">(</span>index<span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> clear<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>list <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span></code></pre><h2 id="网络应用"><a href="#网络应用" class="headerlink" title="网络应用"></a>网络应用</h2><p>Vue结合网络数据开发应用</p><h3 id="axios基本使用"><a href="#axios基本使用" class="headerlink" title="axios基本使用"></a>axios基本使用</h3><p>引入，使用cdn</p><pre class=" language-xml"><code class="language-xml"> <span class="token comment" spellcheck="true"><!-- 官网提供的 axios 在线地址 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://unpkg.com/axios/dist/axios.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span>axios.get(url?key=value1&key2=value2).then(function(response){请求成功触发},function(err){失败触发})axios.post(url?对象参数).then(function(response){请求成功触发},function(err){失败触发})</code></pre><p>get与post请求</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>get请求<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>get<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>post请求<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>post<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://unpkg.com/axios/dist/axios.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token comment" spellcheck="true">/* 接口:随机获取一条笑话 请求地址:https://autumnfish.cn/api/joke 请求方法:get 请求参数:无 响应内容:随机笑话 */</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">".get"</span><span class="token punctuation">)</span><span class="token punctuation">.</span>onclick <span class="token operator">=</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> axios<span class="token punctuation">.</span><span class="token keyword">get</span><span class="token punctuation">(</span><span class="token string">"https://autumnfish.cn/api/joke/list?num=3"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span><span class="token keyword">function</span><span class="token punctuation">(</span>response<span class="token punctuation">)</span><span class="token punctuation">{</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>response<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">,</span><span class="token keyword">function</span><span class="token punctuation">(</span>err<span class="token punctuation">)</span><span class="token punctuation">{</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>err<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">".post"</span><span class="token punctuation">)</span><span class="token punctuation">.</span>onclick <span class="token operator">=</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> axios<span class="token punctuation">.</span><span class="token function">post</span><span class="token punctuation">(</span><span class="token string">"https://autumnfish.cn/api/user/reg"</span><span class="token punctuation">,</span><span class="token punctuation">{</span>username<span class="token punctuation">:</span><span class="token string">"Tom1jk"</span><span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span><span class="token keyword">function</span><span class="token punctuation">(</span>response<span class="token punctuation">)</span><span class="token punctuation">{</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>response<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">,</span><span class="token keyword">function</span><span class="token punctuation">(</span>err<span class="token punctuation">)</span><span class="token punctuation">{</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>err<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span></code></pre><h3 id="axios结合Vue"><a href="#axios结合Vue" class="headerlink" title="axios结合Vue"></a>axios结合Vue</h3><p>axios结合Vue开发网络应用，axios回调函数中的this已经改变，无法访问到data中的数据，可以在函数调用前保存this，回调函数直接使用保存的this即可，和本地应用最大的区别就是数据来源</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>get请求获取笑话<span class="token punctuation">"</span></span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>getJoke<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span>{{ joke }}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://unpkg.com/axios/dist/axios.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token comment" spellcheck="true">/* 接口:随机获取一条笑话 请求地址:https://autumnfish.cn/api/joke 请求方法:get 请求参数:无 响应内容:随机笑话 */</span> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span><span class="token string">"#app"</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span><span class="token punctuation">{</span> joke<span class="token punctuation">:</span><span class="token string">"很好笑的笑话"</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span><span class="token punctuation">{</span> getJoke<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">var</span> that <span class="token operator">=</span> <span class="token keyword">this</span><span class="token punctuation">;</span> axios<span class="token punctuation">.</span><span class="token keyword">get</span><span class="token punctuation">(</span><span class="token string">"https://autumnfish.cn/api/joke"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span><span class="token keyword">function</span><span class="token punctuation">(</span>response<span class="token punctuation">)</span><span class="token punctuation">{</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>response<span class="token punctuation">)</span><span class="token punctuation">;</span> that<span class="token punctuation">.</span>joke<span class="token operator">=</span>response<span class="token punctuation">.</span>data<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">,</span><span class="token keyword">function</span><span class="token punctuation">(</span>err<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span></code></pre><h3 id="天气预报"><a href="#天气预报" class="headerlink" title="天气预报"></a>天气预报</h3><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>app<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h1</span><span class="token punctuation">></span></span>天气接口demo<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h1</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>查询天气<span class="token punctuation">"</span></span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>getWeather<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text<span class="token punctuation">"</span></span> <span class="token attr-name">v-model</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>city<span class="token punctuation">"</span></span> <span class="token attr-name">@keyup.enter</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>getWeather<span class="token punctuation">"</span></span> <span class="token attr-name">placeholder</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>输入你要查询的天气<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>li</span> <span class="token attr-name">v-for</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>(item,index) in list<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> {{ item }} <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>li</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://unpkg.com/axios/dist/axios.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 导入自己的js --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>./main.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span></code></pre><pre class=" language-javascript"><code class="language-javascript"><span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span><span class="token string">"#app"</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span><span class="token punctuation">{</span> city<span class="token punctuation">:</span><span class="token string">''</span><span class="token punctuation">,</span> list<span class="token punctuation">:</span><span class="token punctuation">[</span><span class="token punctuation">]</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> methods<span class="token punctuation">:</span><span class="token punctuation">{</span> getWeather<span class="token punctuation">:</span><span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">var</span> that <span class="token operator">=</span> <span class="token keyword">this</span><span class="token punctuation">;</span> axios<span class="token punctuation">.</span><span class="token keyword">get</span><span class="token punctuation">(</span><span class="token string">"https://www.tianqiapi.com/free/day?appid=75698768&appsecret=7LyHELsc&city="</span><span class="token operator">+</span><span class="token keyword">this</span><span class="token punctuation">.</span>city<span class="token punctuation">)</span> <span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span><span class="token keyword">function</span><span class="token punctuation">(</span>response<span class="token punctuation">)</span><span class="token punctuation">{</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>response<span class="token punctuation">.</span>data<span class="token punctuation">)</span><span class="token punctuation">;</span> that<span class="token punctuation">.</span>list <span class="token operator">=</span> response<span class="token punctuation">.</span>data<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token punctuation">.</span><span class="token keyword">catch</span><span class="token punctuation">(</span><span class="token keyword">function</span><span class="token punctuation">(</span>err<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span></code></pre><h2 id="网易云接口"><a href="#网易云接口" class="headerlink" title="网易云接口"></a>网易云接口</h2><pre class=" language-xml"><code class="language-xml">// 设置axios的基地址 axios.defaults.baseURL = 'https://autumnfish.cn';</code></pre><pre class=" language-html"><code class="language-html"><span class="token doctype"><!DOCTYPE html></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>html</span> <span class="token attr-name">lang</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>en<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>meta</span> <span class="token attr-name">charset</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>UTF-8<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>meta</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>viewport<span class="token punctuation">"</span></span> <span class="token attr-name">content</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>width<span class="token punctuation">=</span>device-width, initial-scale<span class="token punctuation">=</span>1.0<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>meta</span> <span class="token attr-name">http-equiv</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>X-UA-Compatible<span class="token punctuation">"</span></span> <span class="token attr-name">content</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>ie<span class="token punctuation">=</span>edge<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>title</span><span class="token punctuation">></span></span>云播放器<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>title</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 样式 --></span><span class="token comment" spellcheck="true"><!-- <link rel="stylesheet" href="./css/index.css">--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>style</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/css<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token style language-css"> <span class="token selector">body, ul, dl, dd </span><span class="token punctuation">{</span> <span class="token property">margin</span><span class="token punctuation">:</span> <span class="token number">0</span>px<span class="token punctuation">;</span> <span class="token property">padding</span><span class="token punctuation">:</span> <span class="token number">0</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.wrap</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> fixed<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token property">background</span><span class="token punctuation">:</span> <span class="token url">url("https://ss0.baidu.com/7Po3dSag_xI4khGko9WTAnF6hhy/zhidao/pic/item/42166d224f4a20a4499222d690529822720ed016.jpg")</span> no-repeat<span class="token punctuation">;</span> <span class="token property">background-size</span><span class="token punctuation">:</span> <span class="token number">100%</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.play_wrap</span> </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">800</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">544</span>px<span class="token punctuation">;</span> <span class="token property">position</span><span class="token punctuation">:</span> fixed<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">50%</span><span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">50%</span><span class="token punctuation">;</span> <span class="token property">margin-left</span><span class="token punctuation">:</span> -<span class="token number">400</span>px<span class="token punctuation">;</span> <span class="token property">margin-top</span><span class="token punctuation">:</span> -<span class="token number">272</span>px<span class="token punctuation">;</span> <span class="token comment" spellcheck="true">/* background-color: #f9f9f9; */</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.search_bar</span> </span><span class="token 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punctuation">:</span> <span class="token number">23</span>px<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">296</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">34</span>px<span class="token punctuation">;</span> <span class="token property">border-radius</span><span class="token punctuation">:</span> <span class="token number">17</span>px<span class="token punctuation">;</span> <span class="token property">border</span><span class="token punctuation">:</span> <span class="token number">0</span>px<span class="token punctuation">;</span> <span class="token property">background</span><span class="token punctuation">:</span> <span class="token url">url("https://gitee.com/maoshencat/imgpng/raw/master/player/search.png")</span> <span class="token number">265</span>px center 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property">background-color</span><span class="token punctuation">:</span> <span class="token function">rgba</span><span class="token punctuation">(</span><span class="token number">255</span>, <span class="token number">255</span>, <span class="token number">255</span>, <span class="token number">0.5</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token property">display</span><span class="token punctuation">:</span> flex<span class="token punctuation">;</span> <span class="token property">position</span><span class="token punctuation">:</span> relative<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_wrapper</span> </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">200</span>px<span class="token punctuation">;</span> <span class="token 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property">overflow-x</span><span class="token punctuation">:</span> hidden<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_list</span><span class="token pseudo-element">::-webkit-scrollbar</span> </span><span class="token punctuation">{</span> <span class="token property">display</span><span class="token punctuation">:</span> none<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_list</span> li </span><span class="token punctuation">{</span> <span class="token property">font-size</span><span class="token punctuation">:</span> <span class="token number">12</span>px<span class="token punctuation">;</span> <span class="token property">color</span><span class="token punctuation">:</span> <span class="token hexcode">#333</span><span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">40</span>px<span class="token punctuation">;</span> <span class="token property">display</span><span class="token punctuation">:</span> flex<span class="token punctuation">;</span> <span class="token property">flex-wrap</span><span class="token punctuation">:</span> wrap<span class="token punctuation">;</span> <span class="token property">align-items</span><span class="token punctuation">:</span> center<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">580</span>px<span class="token punctuation">;</span> <span class="token property">padding-left</span><span class="token punctuation">:</span> <span class="token number">10</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_list</span> li<span class="token pseudo-class">:nth-child(odd)</span> </span><span class="token punctuation">{</span> <span class="token property">background-color</span><span class="token punctuation">:</span> <span class="token function">rgba</span><span class="token punctuation">(</span><span class="token number">240</span>, <span class="token number">240</span>, <span class="token number">240</span>, <span class="token number">0.3</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_list</span> li a </span><span class="token punctuation">{</span> <span class="token property">display</span><span class="token punctuation">:</span> block<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">17</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">17</span>px<span class="token punctuation">;</span> <span class="token property">background-image</span><span class="token punctuation">:</span> <span class="token url">url("https://gitee.com/maoshencat/imgpng/raw/master/player/bofang.png")</span><span class="token punctuation">;</span> <span class="token property">background-size</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token property">margin-right</span><span class="token punctuation">:</span> <span class="token number">5</span>px<span class="token punctuation">;</span> <span class="token property">box-sizing</span><span class="token punctuation">:</span> border-box<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_list</span> li b </span><span class="token punctuation">{</span> <span class="token property">font-weight</span><span class="token punctuation">:</span> normal<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">122</span>px<span class="token punctuation">;</span> <span class="token property">overflow</span><span class="token punctuation">:</span> hidden<span class="token punctuation">;</span> <span class="token property">text-overflow</span><span class="token punctuation">:</span> ellipsis<span class="token punctuation">;</span> <span class="token property">white-space</span><span class="token punctuation">:</span> nowrap<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_stretch</span> <span class="token class">.song_list</span> li b </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">200</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_stretch</span> <span class="token class">.song_list</span> li em </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">150</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_list</span> li span </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">23</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">17</span>px<span class="token punctuation">;</span> <span class="token property">margin-right</span><span class="token punctuation">:</span> <span class="token number">50</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_list</span> li span i </span><span class="token punctuation">{</span> <span class="token property">display</span><span class="token punctuation">:</span> block<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token property">cursor</span><span class="token punctuation">:</span> pointer<span class="token punctuation">;</span> <span class="token property">background</span><span class="token punctuation">:</span> <span class="token url">url("https://gitee.com/maoshencat/imgpng/raw/master/player/table.png")</span> left -<span class="token number">48</span>px no-repeat<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.song_list</span> li em, <span class="token class">.song_list</span> li i </span><span class="token punctuation">{</span> <span class="token property">font-style</span><span class="token punctuation">:</span> normal<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">100</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.player_con</span> </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">400</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">435</span>px<span class="token punctuation">;</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">200</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">0</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.player_con2</span> </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">400</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">435</span>px<span class="token punctuation">;</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">200</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">0</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.player_con2</span> video </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">20</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">30</span>px<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">355</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">265</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.disc</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">73</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">60</span>px<span class="token punctuation">;</span> <span class="token property">z-index</span><span class="token punctuation">:</span> <span class="token number">9</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.cover</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">125</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span 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punctuation">:</span> <span class="token number">180</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">435</span>px<span class="token punctuation">;</span> <span class="token property">list-style</span><span class="token punctuation">:</span> none<span class="token punctuation">;</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">600</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">0</span>px<span class="token punctuation">;</span> <span class="token property">padding</span><span class="token punctuation">:</span> <span class="token number">25</span>px <span class="token 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class="token punctuation">:</span> auto<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">410</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.comment_wrapper</span> <span class="token class">.comment_list</span><span class="token pseudo-element">::-webkit-scrollbar</span> </span><span class="token punctuation">{</span> <span class="token property">display</span><span class="token punctuation">:</span> none<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.comment_wrapper</span> dl </span><span class="token punctuation">{</span> <span class="token property">padding-top</span><span class="token punctuation">:</span> <span class="token number">10</span>px<span class="token punctuation">;</span> <span class="token property">padding-left</span><span class="token punctuation">:</span> <span class="token number">55</span>px<span class="token punctuation">;</span> <span class="token property">position</span><span class="token punctuation">:</span> relative<span class="token punctuation">;</span> <span class="token property">margin-bottom</span><span class="token punctuation">:</span> <span class="token number">20</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.comment_wrapper</span> dt </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">4</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">10</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.comment_wrapper</span> dt img </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">40</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">40</span>px<span class="token punctuation">;</span> <span class="token property">border-radius</span><span class="token punctuation">:</span> <span class="token number">20</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.comment_wrapper</span> dd </span><span class="token punctuation">{</span> <span class="token property">font-size</span><span class="token punctuation">:</span> <span class="token number">12</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.comment_wrapper</span> <span class="token class">.name</span> </span><span class="token punctuation">{</span> <span class="token property">font-weight</span><span class="token punctuation">:</span> bold<span class="token punctuation">;</span> <span class="token property">color</span><span class="token punctuation">:</span> <span class="token hexcode">#333</span><span class="token punctuation">;</span> <span class="token property">padding-top</span><span class="token punctuation">:</span> <span class="token number">5</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.comment_wrapper</span> <span class="token class">.detail</span> </span><span class="token punctuation">{</span> <span class="token property">color</span><span class="token punctuation">:</span> <span class="token hexcode">#666</span><span class="token punctuation">;</span> <span class="token property">margin-top</span><span class="token punctuation">:</span> <span class="token number">5</span>px<span class="token punctuation">;</span> <span class="token property">line-height</span><span class="token punctuation">:</span> <span class="token number">18</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.audio_con</span> </span><span class="token punctuation">{</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">50</span>px<span class="token punctuation">;</span> <span class="token property">background-color</span><span class="token punctuation">:</span> <span class="token hexcode">#f1f3f4</span><span class="token punctuation">;</span> <span class="token property">border-bottom-left-radius</span><span class="token punctuation">:</span> <span class="token number">4</span>px<span class="token punctuation">;</span> <span class="token property">border-bottom-right-radius</span><span class="token punctuation">:</span> <span class="token number">4</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.myaudio</span> </span><span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">800</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">40</span>px<span class="token punctuation">;</span> <span class="token property">margin-top</span><span class="token punctuation">:</span> <span class="token number">5</span>px<span class="token punctuation">;</span> <span class="token property">outline</span><span class="token punctuation">:</span> none<span class="token punctuation">;</span> <span class="token property">background-color</span><span class="token punctuation">:</span> <span class="token hexcode">#f1f3f4</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token comment" spellcheck="true">/* 旋转的动画 */</span> <span class="token atrule"><span class="token rule">@keyframes</span> Rotate</span> <span class="token punctuation">{</span> <span class="token selector">from </span><span class="token punctuation">{</span> <span class="token property">transform</span><span class="token punctuation">:</span> <span class="token function">rotateZ</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector">to </span><span class="token punctuation">{</span> <span class="token property">transform</span><span class="token punctuation">:</span> <span class="token function">rotateZ</span><span class="token punctuation">(</span><span class="token number">360</span>deg<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token comment" spellcheck="true">/* 旋转的类名 */</span> <span class="token selector"><span class="token class">.autoRotate</span> </span><span class="token punctuation">{</span> <span class="token property">animation-name</span><span class="token punctuation">:</span> Rotate<span class="token punctuation">;</span> <span class="token property">animation-iteration-count</span><span class="token punctuation">:</span> infinite<span class="token punctuation">;</span> <span class="token property">animation-play-state</span><span class="token punctuation">:</span> paused<span class="token punctuation">;</span> <span class="token property">animation-timing-function</span><span class="token punctuation">:</span> linear<span class="token punctuation">;</span> <span class="token property">animation-duration</span><span class="token punctuation">:</span> <span class="token number">5</span>s<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token comment" spellcheck="true">/* 是否正在播放 */</span> <span class="token selector"><span class="token class">.player_con.playing</span> <span class="token class">.disc</span>, <span class="token class">.player_con.playing</span> <span class="token class">.cover</span> </span><span class="token punctuation">{</span> <span class="token property">animation-play-state</span><span class="token punctuation">:</span> running<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.play_bar</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">200</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> -<span class="token number">10</span>px<span class="token punctuation">;</span> <span class="token property">z-index</span><span class="token punctuation">:</span> <span class="token number">10</span><span class="token punctuation">;</span> <span class="token property">transform</span><span class="token punctuation">:</span> <span class="token function">rotate</span><span class="token punctuation">(</span>-<span class="token number">25</span>deg<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token property">transform-origin</span><span class="token punctuation">:</span> <span class="token number">12</span>px <span class="token number">12</span>px<span class="token punctuation">;</span> <span class="token property">transition</span><span class="token punctuation">:</span> <span class="token number">1</span>s<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token comment" spellcheck="true">/* 播放杆 转回去 */</span> <span class="token selector"><span class="token class">.player_con.playing</span> <span class="token class">.play_bar</span> </span><span class="token punctuation">{</span> <span class="token property">transform</span><span class="token punctuation">:</span> <span class="token function">rotate</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token comment" spellcheck="true">/* 搜索历史列表 */</span> <span class="token selector"><span class="token class">.search_history</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">296</span>px<span class="token punctuation">;</span> <span class="token property">overflow</span><span class="token punctuation">:</span> hidden<span class="token punctuation">;</span> <span class="token property">background-color</span><span class="token punctuation">:</span> <span class="token function">rgba</span><span class="token punctuation">(</span><span class="token number">255</span>, <span class="token number">255</span>, <span class="token number">255</span>, <span class="token number">0.3</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token property">list-style</span><span class="token punctuation">:</span> none<span class="token punctuation">;</span> <span class="token property">right</span><span class="token punctuation">:</span> <span class="token number">23</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">50</span>px<span class="token punctuation">;</span> <span class="token property">box-sizing</span><span class="token punctuation">:</span> border-box<span class="token punctuation">;</span> <span class="token property">padding</span><span class="token punctuation">:</span> <span class="token number">10</span>px <span class="token number">20</span>px<span class="token punctuation">;</span> <span class="token property">border-radius</span><span class="token punctuation">:</span> <span class="token number">17</span>px<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.search_history</span> li </span><span class="token punctuation">{</span> <span class="token property">line-height</span><span class="token punctuation">:</span> <span class="token number">24</span>px<span class="token punctuation">;</span> <span class="token property">font-size</span><span class="token punctuation">:</span> <span class="token number">12</span>px<span class="token punctuation">;</span> <span class="token property">cursor</span><span class="token punctuation">:</span> pointer<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.switch_btn</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">right</span><span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">;</span> <span class="token property">cursor</span><span class="token punctuation">:</span> pointer<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.right_line</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> absolute<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.video_con</span> video </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> fixed<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">800</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">546</span>px<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">50%</span><span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">50%</span><span class="token punctuation">;</span> <span class="token property">margin-top</span><span class="token punctuation">:</span> -<span class="token number">273</span>px<span class="token punctuation">;</span> <span class="token property">transform</span><span class="token punctuation">:</span> <span class="token function">translateX</span><span class="token punctuation">(</span>-<span class="token number">50%</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token property">z-index</span><span class="token punctuation">:</span> <span class="token number">990</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.video_con</span> <span class="token class">.mask</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> fixed<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">0</span><span class="token punctuation">;</span> <span class="token property">z-index</span><span class="token punctuation">:</span> <span class="token number">980</span><span class="token punctuation">;</span> <span class="token property">background-color</span><span class="token punctuation">:</span> <span class="token function">rgba</span><span class="token punctuation">(</span><span class="token number">0</span>, <span class="token number">0</span>, <span class="token number">0</span>, <span class="token number">0.8</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector"><span class="token class">.video_con</span> <span class="token class">.shutoff</span> </span><span class="token punctuation">{</span> <span class="token property">position</span><span class="token punctuation">:</span> fixed<span class="token punctuation">;</span> <span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">40</span>px<span class="token punctuation">;</span> <span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">40</span>px<span class="token punctuation">;</span> <span class="token property">background</span><span class="token punctuation">:</span> <span class="token url">url("https://gitee.com/maoshencat/imgpng/raw/master/player/close.png")</span> no-repeat<span class="token punctuation">;</span> <span class="token property">left</span><span class="token punctuation">:</span> <span class="token number">50%</span><span class="token punctuation">;</span> <span class="token property">margin-left</span><span class="token punctuation">:</span> <span class="token number">400</span>px<span class="token punctuation">;</span> <span class="token property">margin-top</span><span class="token punctuation">:</span> -<span class="token number">273</span>px<span class="token punctuation">;</span> <span class="token property">top</span><span class="token punctuation">:</span> <span class="token number">50%</span><span class="token punctuation">;</span> <span class="token property">z-index</span><span class="token punctuation">:</span> <span class="token number">995</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>style</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>head</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>wrap<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>play_wrap<span class="token punctuation">"</span></span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>player<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>search_bar<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://gitee.com/maoshencat/imgpng/raw/master/player/logo.png<span class="token punctuation">"</span></span> <span class="token attr-name">height</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>60<span class="token punctuation">"</span></span> <span class="token attr-name">width</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>40<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token comment" spellcheck="true"><!-- 搜索歌曲 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text<span class="token punctuation">"</span></span> <span class="token attr-name">placeholder</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>输入要搜索的Music<span class="token punctuation">"</span></span> <span class="token attr-name">autocomplete</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>off<span class="token punctuation">"</span></span> <span class="token attr-name">v-model</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>query<span class="token punctuation">'</span></span> <span class="token attr-name">@keyup.enter</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>searchMusic();<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>center_con<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 搜索歌曲列表 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>song_wrapper<span class="token punctuation">'</span></span> <span class="token attr-name">ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>song_wrapper<span class="token punctuation">'</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ul</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>song_list<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>li</span> <span class="token attr-name">v-for</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>item in musicList<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 点击放歌 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>a</span> <span class="token attr-name">href</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>javascript:;<span class="token punctuation">"</span></span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>playMusic(item.id)<span class="token punctuation">'</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>a</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>b</span><span class="token punctuation">></span></span>{{item.name}}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>b</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>span</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>i</span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>playMv(item.mvid)<span class="token punctuation">"</span></span> <span class="token attr-name">v-if</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>item.mvid!<span class="token punctuation">=</span>0<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>i</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>span</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>li</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ul</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://gitee.com/maoshencat/imgpng/raw/master/player/line.png<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>switch_btn<span class="token punctuation">"</span></span> <span class="token attr-name">alt</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span><span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 歌曲信息容器 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>player_con<span class="token punctuation">"</span></span> <span class="token attr-name">:class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>{playing:isPlay}<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://gitee.com/maoshencat/imgpng/raw/master/player/play.png<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>play_bar<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token comment" spellcheck="true"><!-- 黑胶碟片 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://gitee.com/maoshencat/imgpng/raw/master/player/yuan.png<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>disc autoRotate<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">:src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>coverUrl<span class="token punctuation">=</span><span class="token punctuation">=</span><span class="token punctuation">'</span><span class="token punctuation">'</span>?<span class="token punctuation">'</span>https://gitee.com/maoshencat/imgpng/raw/master/player/logo.png<span class="token punctuation">'</span>:coverUrl<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cover autoRotate<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 评论容器 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>comment_wrapper<span class="token punctuation">"</span></span> <span class="token attr-name">ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>comment_wrapper<span class="token punctuation">'</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h5</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>title<span class="token punctuation">'</span></span><span class="token punctuation">></span></span>热门留言<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h5</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>comment_list<span class="token punctuation">'</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dl</span> <span class="token attr-name">v-for</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>item in hotComments<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dt</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">:src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>item.user.avatarUrl<span class="token punctuation">"</span></span> <span class="token attr-name">alt</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span><span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dt</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dd</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>{{item.user.nickname}}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dd</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dd</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>detail<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> {{item.content}} <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dd</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dl</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>img</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://gitee.com/maoshencat/imgpng/raw/master/player/line.png<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>right_line<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>audio_con<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 底部进度 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>audio</span> <span class="token attr-name">ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>audio<span class="token punctuation">'</span></span> <span class="token attr-name">@play</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>play<span class="token punctuation">"</span></span> <span class="token attr-name">@pause</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>pause<span class="token punctuation">"</span></span> <span class="token attr-name">:src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>musicUrl<span class="token punctuation">"</span></span> <span class="token attr-name">controls</span> <span class="token attr-name">autoplay</span> <span class="token attr-name">loop</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>myaudio<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>audio</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>video_con<span class="token punctuation">"</span></span> <span class="token attr-name">v-show</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>showVideo<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>video</span> <span class="token attr-name">ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">'</span>video<span class="token punctuation">'</span></span> <span class="token attr-name">:src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>mvUrl<span class="token punctuation">"</span></span> <span class="token attr-name">controls</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>controls<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>video</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>mask<span class="token punctuation">"</span></span> <span class="token attr-name">@click</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>closeMv<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 开发环境版本，包含了有帮助的命令行警告 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdn.jsdelivr.net/npm/vue/dist/vue.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 官网提供的 axios 在线地址 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://unpkg.com/axios/dist/axios.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/javascript<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token comment" spellcheck="true">// 设置axios的基地址</span> axios<span class="token punctuation">.</span>defaults<span class="token punctuation">.</span>baseURL <span class="token operator">=</span> <span class="token string">'https://autumnfish.cn'</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">// axios.defaults.baseURL = 'http://localhost:3000';</span> <span class="token comment" spellcheck="true">// 实例化vue</span> <span class="token keyword">var</span> app <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Vue</span><span class="token punctuation">(</span><span class="token punctuation">{</span> el<span class="token punctuation">:</span> <span class="token string">"#player"</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 搜索关键字</span> query<span class="token punctuation">:</span> <span class="token string">''</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 歌曲列表</span> musicList<span class="token punctuation">:</span> <span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 歌曲url</span> musicUrl<span class="token punctuation">:</span> <span class="token string">''</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 是否正在播放</span> isPlay<span class="token punctuation">:</span> <span class="token boolean">false</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 歌曲热门评论</span> hotComments<span class="token punctuation">:</span> <span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 歌曲封面地址</span> coverUrl<span class="token punctuation">:</span> <span class="token string">''</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 显示视频播放</span> showVideo<span class="token punctuation">:</span> <span class="token boolean">false</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// mv地址</span> mvUrl<span class="token punctuation">:</span> <span class="token string">''</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 方法</span> methods<span class="token punctuation">:</span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 搜索歌曲</span> <span class="token function">searchMusic</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">.</span>query <span class="token operator">==</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">return</span> <span class="token punctuation">}</span> axios<span class="token punctuation">.</span><span class="token keyword">get</span><span class="token punctuation">(</span><span class="token string">'/search?keywords='</span> <span class="token operator">+</span> <span class="token keyword">this</span><span class="token punctuation">.</span>query<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>response <span class="token operator">=</span><span class="token operator">></span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 保存内容</span> <span class="token keyword">this</span><span class="token punctuation">.</span>musicList <span class="token operator">=</span> response<span class="token punctuation">.</span>data<span class="token punctuation">.</span>result<span class="token punctuation">.</span>songs<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token comment" spellcheck="true">// 清空搜索</span> <span class="token keyword">this</span><span class="token punctuation">.</span>query <span class="token operator">=</span> <span class="token string">''</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 播放歌曲</span> <span class="token function">playMusic</span><span class="token punctuation">(</span>musicId<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 获取歌曲url</span> axios<span class="token punctuation">.</span><span class="token keyword">get</span><span class="token punctuation">(</span><span class="token string">'/song/url?id='</span> <span class="token operator">+</span> musicId<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>response <span class="token operator">=</span><span class="token operator">></span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// 保存歌曲url地址</span> <span class="token keyword">this</span><span class="token punctuation">.</span>musicUrl <span class="token operator">=</span> response<span class="token punctuation">.</span>data<span class="token punctuation">.</span>data<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span><span class="token punctuation">.</span>url <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token comment" spellcheck="true">// 获取歌曲热门评论</span> axios<span class="token punctuation">.</span><span class="token keyword">get</span><span class="token punctuation">(</span><span class="token string">'/comment/hot?type=0&id='</span> <span class="token operator">+</span> musicId<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>response <span class="token operator">=</span><span class="token operator">></span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// console.log(response)</span> <span class="token comment" spellcheck="true">// 保存热门评论</span> <span class="token keyword">this</span><span class="token punctuation">.</span>hotComments <span class="token operator">=</span> response<span class="token punctuation">.</span>data<span class="token punctuation">.</span>hotComments <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token comment" spellcheck="true">// 获取歌曲封面</span> axios<span class="token punctuation">.</span><span class="token keyword">get</span><span class="token punctuation">(</span><span class="token string">'/song/detail?ids='</span> <span class="token operator">+</span> musicId<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>response <span class="token operator">=</span><span class="token operator">></span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// console.log(response)</span> <span class="token comment" spellcheck="true">// 设置封面</span> <span class="token keyword">this</span><span class="token punctuation">.</span>coverUrl <span class="token operator">=</span> response<span class="token punctuation">.</span>data<span class="token punctuation">.</span>songs<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span><span class="token punctuation">.</span>al<span class="token punctuation">.</span>picUrl <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// audio的play事件</span> <span class="token function">play</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>isPlay <span class="token operator">=</span> <span class="token boolean">true</span> <span class="token comment" spellcheck="true">// 清空mv的信息</span> <span class="token keyword">this</span><span class="token punctuation">.</span>mvUrl <span class="token operator">=</span> <span class="token string">''</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// audio的pause事件</span> <span class="token function">pause</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>isPlay <span class="token operator">=</span> <span class="token boolean">false</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 播放mv</span> <span class="token function">playMv</span><span class="token punctuation">(</span>vid<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>vid<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>showVideo <span class="token operator">=</span> <span class="token boolean">true</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">// 获取mv信息</span> axios<span class="token punctuation">.</span><span class="token keyword">get</span><span class="token punctuation">(</span><span class="token string">'/mv/url?id='</span> <span class="token operator">+</span> vid<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>response <span class="token operator">=</span><span class="token operator">></span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">// console.log(response)</span> <span class="token comment" spellcheck="true">// 暂停歌曲播放</span> <span class="token keyword">this</span><span class="token punctuation">.</span>$refs<span class="token punctuation">.</span>audio<span class="token punctuation">.</span><span class="token function">pause</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token comment" spellcheck="true">// 获取mv地址</span> <span class="token keyword">this</span><span class="token punctuation">.</span>mvUrl <span class="token operator">=</span> response<span class="token punctuation">.</span>data<span class="token punctuation">.</span>data<span class="token punctuation">.</span>url <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 关闭mv界面</span> <span class="token function">closeMv</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>showVideo <span class="token operator">=</span> <span class="token boolean">false</span> <span class="token keyword">this</span><span class="token punctuation">.</span>$refs<span class="token punctuation">.</span>video<span class="token punctuation">.</span><span class="token function">pause</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token comment" spellcheck="true">// 搜索历史记录中的歌曲</span> <span class="token function">historySearch</span><span class="token punctuation">(</span>history<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>query <span class="token operator">=</span> history <span class="token keyword">this</span><span class="token punctuation">.</span><span class="token function">searchMusic</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token keyword">this</span><span class="token punctuation">.</span>showHistory <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">,</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>html</span><span class="token punctuation">></span></span></code></pre>]]></content>
<tags>
<tag> vue </tag>
</tags>
</entry>
<entry>
<title>ajax</title>
<link href="2021/06/07/ajax/"/>
<url>2021/06/07/ajax/</url>
<content type="html"><![CDATA[<h2 id="什么是Ajax"><a href="#什么是Ajax" class="headerlink" title="什么是Ajax"></a>什么是Ajax</h2><p><strong>AJAX是创建交互式网页应用的网页开发技术的一种。Ajax 不是一种新的编程语言，而是一种用于创建更好更快以及交互性更强的Web应用程序的技术。</strong></p><p>Ajax = 异步 JavaScript 和 XML 或者是 HTML（标准通用标记语言的子集）。可以用于创建快速动态网页的技术。在无需重新加载整个网页的情况下，能够更新部分网页的技术。通过在后台与服务器进行少量数据交换，Ajax 可以使网页实现异步更新。这意味着可以在不重新加载整个网页的情况下，对网页的某部分进行更新。</p><p>我们可以使用前端的一个标签来伪造一个Ajax的样子。</p><pre class=" language-xml"><code class="language-xml"><span class="token doctype"><!DOCTYPE html></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>html</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>head</span> <span class="token attr-name">lang</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>en<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>meta</span> <span class="token attr-name">charset</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>title</span><span class="token punctuation">></span></span>ajax<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>title</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>head</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/javascript<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token comment" spellcheck="true">/*当页面加载时，加载时间错*/</span> window<span class="token punctuation">.</span>onload <span class="token operator">=</span> <span class="token keyword">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">let</span> myDate <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Date</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> document<span class="token punctuation">.</span><span class="token function">getElementById</span><span class="token punctuation">(</span><span class="token string">'currentTime'</span><span class="token punctuation">)</span><span class="token punctuation">.</span>innerText <span class="token operator">=</span> myDate<span class="token punctuation">.</span><span class="token function">getTime</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">;</span> <span class="token keyword">function</span> <span class="token function">LoadPage</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">let</span> targetUrl <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">getElementById</span><span class="token punctuation">(</span><span class="token string">'url'</span><span class="token punctuation">)</span><span class="token punctuation">.</span>value<span class="token punctuation">;</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>targetUrl<span class="token punctuation">)</span><span class="token punctuation">;</span> document<span class="token punctuation">.</span><span class="token function">getElementById</span><span class="token punctuation">(</span><span class="token string">"iframePosition"</span><span class="token punctuation">)</span><span class="token punctuation">.</span>src <span class="token operator">=</span> targetUrl<span class="token punctuation">;</span> <span class="token punctuation">}</span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span>请输入要加载的地址：<span class="token tag"><span class="token tag"><span class="token punctuation"><</span>span</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>currentTime<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>span</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>url<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://www.baidu.com/<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>提交<span class="token punctuation">"</span></span> <span class="token attr-name">onclick</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>LoadPage()<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>div</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>h3</span><span class="token punctuation">></span></span>加载页面位置：<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>h3</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>iframe</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>iframePosition<span class="token punctuation">"</span></span><span class="token style-attr language-css"><span class="token attr-name"> <span class="token attr-name">style</span></span><span class="token punctuation">="</span><span class="token attr-value"><span class="token property">width</span><span class="token punctuation">:</span> <span class="token number">100%</span><span class="token punctuation">;</span><span class="token property">height</span><span class="token punctuation">:</span> <span class="token number">500</span>px<span class="token punctuation">;</span></span><span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>iframe</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>div</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>html</span><span class="token punctuation">></span></span></code></pre><p><strong>利用AJAX可以做：</strong></p><ul><li>注册时，输入用户名自动检测用户是否已经存在。</li><li>登陆时，提示用户名密码错误</li><li>删除数据行时，将行ID发送到后台，后台在数据库中删除，数据库删除成功后，在页面DOM中将数据行也删除。</li><li>….等等</li></ul><h2 id="jQuery-ajax-方法"><a href="#jQuery-ajax-方法" class="headerlink" title="jQuery ajax() 方法"></a>jQuery ajax() 方法</h2><p>Ajax的核心是XMLHttpRequest对象(XHR)。XHR为向服务器发送请求和解析服务器响应提供了接口。能够以异步方式从服务器获取新数据。</p><pre class=" language-xml"><code class="language-xml">jQuery.ajax(...) 部分参数： url：请求地址 type：请求方式，GET、POST（1.9.0之后用method） headers：请求头 data：要发送的数据 contentType：即将发送信息至服务器的内容编码类型(默认: "application/x-www-form-urlencoded; charset=UTF-8") async：是否异步 timeout：设置请求超时时间（毫秒） beforeSend：发送请求前执行的函数(全局) complete：完成之后执行的回调函数(全局) success：成功之后执行的回调函数(全局) error：失败之后执行的回调函数(全局) accepts：通过请求头发送给服务器，告诉服务器当前客户端可接受的数据类型 dataType：将服务器端返回的数据转换成指定类型 "xml": 将服务器端返回的内容转换成xml格式 "text": 将服务器端返回的内容转换成普通文本格式 "html": 将服务器端返回的内容转换成普通文本格式，在插入DOM中时，如果包含JavaScript标签，则会尝试去执行。 "script": 尝试将返回值当作JavaScript去执行，然后再将服务器端返回的内容转换成普通文本格式 "json": 将服务器端返回的内容转换成相应的JavaScript对象 "jsonp": JSONP 格式使用 JSONP 形式调用函数时，如 "myurl?callback=?" jQuery 将自动替换 ? 为正确的函数名，以执行回调函数</code></pre><p>jQuery 提供多个与 AJAX 有关的方法。</p><p>通过 jQuery AJAX 方法，您能够使用 HTTP Get 和 HTTP Post 从远程服务器上请求文本、HTML、XML 或 JSON – 同时您能够把这些外部数据直接载入网页的被选元素中。</p><p>jQuery 不是生产者，而是大自然搬运工。</p><p>jQuery Ajax本质就是 XMLHttpRequest，对他进行了封装，方便调用！</p><h2 id="使用"><a href="#使用" class="headerlink" title="使用"></a>使用</h2><h3 id="1，使用最原始的HttpServletResponse处理"><a href="#1，使用最原始的HttpServletResponse处理" class="headerlink" title="1，使用最原始的HttpServletResponse处理"></a>1，使用最原始的HttpServletResponse处理</h3><p>编写controller</p><pre class=" language-java"><code class="language-java"> <span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/index"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> String <span class="token function">Index</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> <span class="token string">"ajax1"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/a1"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">ajax1</span><span class="token punctuation">(</span>String name <span class="token punctuation">,</span> HttpServletResponse response<span class="token punctuation">)</span> <span class="token keyword">throws</span> IOException <span class="token punctuation">{</span> <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token string">"admin"</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> response<span class="token punctuation">.</span><span class="token function">getWriter</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">print</span><span class="token punctuation">(</span><span class="token string">"true"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token keyword">else</span><span class="token punctuation">{</span> response<span class="token punctuation">.</span><span class="token function">getWriter</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">print</span><span class="token punctuation">(</span><span class="token string">"false"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span></code></pre><p>2，当失去焦点时触发事件ajax1.html</p><pre class=" language-xml"><code class="language-xml"><span class="token doctype"><!DOCTYPE html></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>html</span> <span class="token attr-name">lang</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>en<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>meta</span> <span class="token attr-name">charset</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>title</span><span class="token punctuation">></span></span>Title<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>title</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>head</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span><span class="token comment" spellcheck="true"><!--onblur：失去焦点触发事件--></span>用户名:<span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text<span class="token punctuation">"</span></span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>txtName<span class="token punctuation">"</span></span> <span class="token attr-name">onblur</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>a1()<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/javascript<span class="token punctuation">"</span></span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>js/jquery-3.5.1.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/javascript<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">function</span> <span class="token function">a1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> $<span class="token punctuation">.</span><span class="token function">post</span><span class="token punctuation">(</span><span class="token punctuation">{</span> url<span class="token punctuation">:</span><span class="token string">"/a1"</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span><span class="token punctuation">{</span><span class="token string">'name'</span><span class="token punctuation">:</span><span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#txtName"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">val</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">}</span><span class="token punctuation">,</span> success<span class="token punctuation">:</span><span class="token keyword">function</span> <span class="token punctuation">(</span>data<span class="token punctuation">,</span>status<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token function">alert</span><span class="token punctuation">(</span>data<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token function">alert</span><span class="token punctuation">(</span>status<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>html</span><span class="token punctuation">></span></span></code></pre><p>启动springboot 当我们鼠标离开输入框的时候，可以看到发出了一个ajax的请求！是后台返回给我们的结果。</p><h3 id="2，Springmvc实现"><a href="#2，Springmvc实现" class="headerlink" title="2，Springmvc实现"></a>2，Springmvc实现</h3><p>编写实体类User 和controller</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Data</span><span class="token annotation punctuation">@AllArgsConstructor</span><span class="token annotation punctuation">@NoArgsConstructor</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">User</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span> <span class="token keyword">private</span> <span class="token keyword">int</span> age<span class="token punctuation">;</span> <span class="token keyword">private</span> String sex<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><pre class=" language-java"><code class="language-java">获取一个集合对象，展示到前端页面<span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/a2"</span><span class="token punctuation">)</span> <span class="token annotation punctuation">@ResponseBody</span> <span class="token keyword">public</span> List<span class="token operator"><</span>User<span class="token operator">></span> <span class="token function">ajax2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> List<span class="token operator"><</span>User<span class="token operator">></span> list <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ArrayList</span><span class="token operator"><</span>User<span class="token operator">></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> list<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token string">"Ha"</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token string">"男"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> list<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token string">"Ha2"</span><span class="token punctuation">,</span><span class="token number">6</span><span class="token punctuation">,</span><span class="token string">"男"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> list<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token string">"HAHaHa"</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token string">"男"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> list<span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//将list转成json格式返回</span> <span class="token punctuation">}</span></code></pre><p>前端页面</p><pre class=" language-xml"><code class="language-xml"><span class="token doctype"><!DOCTYPE html></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>html</span> <span class="token attr-name">lang</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>en<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>meta</span> <span class="token attr-name">charset</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>title</span><span class="token punctuation">></span></span>Title<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>title</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>head</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>button<span class="token punctuation">"</span></span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>btn<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>获取数据<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>table</span> <span class="token attr-name">width</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>80%<span class="token punctuation">"</span></span> <span class="token attr-name">align</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>center<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>tr</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>td</span><span class="token punctuation">></span></span>姓名<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>td</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>td</span><span class="token punctuation">></span></span>年龄<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>td</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>td</span><span class="token punctuation">></span></span>性别<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>td</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>tr</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>tbody</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>content<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>tbody</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>table</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/javascript<span class="token punctuation">"</span></span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>js/jquery-3.5.1.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token function">$</span><span class="token punctuation">(</span><span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#btn"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">click</span><span class="token punctuation">(</span><span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> $<span class="token punctuation">.</span><span class="token function">post</span><span class="token punctuation">(</span><span class="token string">"/a2"</span><span class="token punctuation">,</span><span class="token keyword">function</span> <span class="token punctuation">(</span>data<span class="token punctuation">)</span> <span class="token punctuation">{</span> console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>data<span class="token punctuation">)</span> <span class="token keyword">let</span> html<span class="token operator">=</span><span class="token string">""</span><span class="token punctuation">;</span> <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">var</span> i <span class="token operator">=</span> <span class="token number">0</span><span class="token punctuation">;</span> i <span class="token operator"><</span>data<span class="token punctuation">.</span>length <span class="token punctuation">;</span> i<span class="token operator">++</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> html<span class="token operator">+</span><span class="token operator">=</span> <span class="token string">"<tr>"</span> <span class="token operator">+</span> <span class="token string">"<td>"</span> <span class="token operator">+</span> data<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">.</span>name <span class="token operator">+</span> <span class="token string">"</td>"</span> <span class="token operator">+</span> <span class="token string">"<td>"</span> <span class="token operator">+</span> data<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">.</span>age <span class="token operator">+</span> <span class="token string">"</td>"</span> <span class="token operator">+</span> <span class="token string">"<td>"</span> <span class="token operator">+</span> data<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">.</span>sex <span class="token operator">+</span> <span class="token string">"</td>"</span> <span class="token operator">+</span> <span class="token string">"</tr>"</span> <span class="token punctuation">}</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#content"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">html</span><span class="token punctuation">(</span>html<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token punctuation">}</span><span class="token punctuation">)</span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>html</span><span class="token punctuation">></span></span></code></pre><p><strong>成功实现了数据回显！</strong></p><h3 id="3，注册提示效果"><a href="#3，注册提示效果" class="headerlink" title="3，注册提示效果"></a>3，注册提示效果</h3><p>写一个Controller（手写用户名admin，密码是123456）</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/a3"</span><span class="token punctuation">)</span> <span class="token annotation punctuation">@ResponseBody</span> <span class="token keyword">public</span> String <span class="token function">ajax3</span><span class="token punctuation">(</span>String name<span class="token punctuation">,</span>String pwd<span class="token punctuation">)</span><span class="token punctuation">{</span> String msg <span class="token operator">=</span> <span class="token string">""</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//模拟数据库中存在数据</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>name<span class="token operator">!=</span>null<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token string">"admin"</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> msg <span class="token operator">=</span> <span class="token string">"OK"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token punctuation">{</span> msg <span class="token operator">=</span> <span class="token string">"用户名输入错误"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>pwd<span class="token operator">!=</span>null<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token string">"123456"</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>pwd<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> msg <span class="token operator">=</span> <span class="token string">"OK"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token punctuation">{</span> msg <span class="token operator">=</span> <span class="token string">"密码输入有误"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token keyword">return</span> msg<span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//将msg转成json格式返回</span> <span class="token punctuation">}</span></code></pre><p>前台页面</p><pre class=" language-xml"><code class="language-xml"><span class="token doctype"><!DOCTYPE html></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>html</span> <span class="token attr-name">lang</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>en<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>meta</span> <span class="token attr-name">charset</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>title</span><span class="token punctuation">></span></span>Title<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>title</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>head</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span> 用户名:<span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text<span class="token punctuation">"</span></span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">onblur</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>a1()<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>span</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>userInfo<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>span</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>p</span><span class="token punctuation">></span></span> 密码:<span class="token tag"><span class="token tag"><span class="token punctuation"><</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text<span class="token punctuation">"</span></span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>pwd<span class="token punctuation">"</span></span> <span class="token attr-name">onblur</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>a2()<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>span</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>pwdInfo<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>span</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>p</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/javascript<span class="token punctuation">"</span></span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>js/jquery-3.5.1.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token keyword">function</span> <span class="token function">a1</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> $<span class="token punctuation">.</span><span class="token function">post</span><span class="token punctuation">(</span><span class="token punctuation">{</span> url<span class="token punctuation">:</span><span class="token string">"/a3"</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span><span class="token punctuation">{</span><span class="token string">'name'</span><span class="token punctuation">:</span><span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#name"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">val</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">}</span><span class="token punctuation">,</span> success<span class="token punctuation">:</span><span class="token keyword">function</span> <span class="token punctuation">(</span>data<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>data<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">==</span><span class="token string">'OK'</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#userInfo"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">css</span><span class="token punctuation">(</span><span class="token string">"color"</span><span class="token punctuation">,</span><span class="token string">"green"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token punctuation">{</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#userInfo"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">css</span><span class="token punctuation">(</span><span class="token string">"color"</span><span class="token punctuation">,</span><span class="token string">"red"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#userInfo"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">html</span><span class="token punctuation">(</span>data<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">function</span> <span class="token function">a2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> $<span class="token punctuation">.</span><span class="token function">post</span><span class="token punctuation">(</span><span class="token punctuation">{</span> url<span class="token punctuation">:</span><span class="token string">"/a3"</span><span class="token punctuation">,</span> data<span class="token punctuation">:</span><span class="token punctuation">{</span><span class="token string">'pwd'</span><span class="token punctuation">:</span><span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#pwd"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">val</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">}</span><span class="token punctuation">,</span> success<span class="token punctuation">:</span><span class="token keyword">function</span> <span class="token punctuation">(</span>data<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>data<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">==</span><span class="token string">'OK'</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#pwdInfo"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">css</span><span class="token punctuation">(</span><span class="token string">"color"</span><span class="token punctuation">,</span><span class="token string">"green"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token keyword">else</span> <span class="token punctuation">{</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#pwdInfo"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">css</span><span class="token punctuation">(</span><span class="token string">"color"</span><span class="token punctuation">,</span><span class="token string">"red"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#pwdInfo"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">html</span><span class="token punctuation">(</span>data<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>html</span><span class="token punctuation">></span></span></code></pre><p>测试一下效果，动态请求响应，局部刷新，就是如此！</p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/ajax/ajax3.PNG" alt="效果"></p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/ajax/list.PNG" alt="文件目录"></p><p>end</p>]]></content>
<tags>
<tag> ajax </tag>
</tags>
</entry>
<entry>
<title>mybatis</title>
<link href="2021/06/06/mybatis/"/>
<url>2021/06/06/mybatis/</url>
<content type="html"><![CDATA[<h2 id="Mybatis"><a href="#Mybatis" class="headerlink" title="Mybatis"></a>Mybatis</h2><p>它是一款半自动的ORM持久层框架，具有较高的SQL灵活性，支持高级映射(一对一，一对多)，动态SQL，延迟加载和缓存等特性，但它的数据库无关性较低，Java 到 MySQL 的映射，开发者可以以⾯向对象的思想来管理数据库。</p><h2 id="什么是ORM？"><a href="#什么是ORM？" class="headerlink" title="什么是ORM？"></a>什么是ORM？</h2><p>Object Relation Mapping，对象关系映射。对象指的是Java对象，关系指的是数据库中的关系模型，对象关系映射，指的就是在Java对象和数据库的关系模型之间建立一种对应关系，比如用一个Java的Student类，去对应数据库中的一张student表，类中的属性和表中的列一一对应。Student类就对应student表，一个Student对象就对应student表中的一行数据</p><p>为什么mybatis是半自动的ORM框架？</p><p>用mybatis进行开发，需要手动编写SQL语句。而全自动的ORM框架，如hibernate，则不需要编写SQL语句。用hibernate开发，只需要定义好ORM映射关系，就可以直接进行CRUD操作了。由于mybatis需要手写SQL语句，所以它有较高的灵活性，可以根据需要，自由地对SQL进行定制，也因为要手写SQL，当要切换数据库时，SQL语句可能就要重写，因为不同的数据库有不同的方言(Dialect)，所以mybatis的数据库无关性低。虽然<strong>mybatis需要手写SQL</strong>，但相比JDBC，它提供了输入映射和输出映射，可以很方便地进行SQL参数设置，以及结果集封装。并且还提供了关联查询和动态SQL等功能，极大地提升了开发的效率。并且它的学习成本也比hibernate低很多。</p><h2 id="Hibernate与Mybatis"><a href="#Hibernate与Mybatis" class="headerlink" title="Hibernate与Mybatis"></a>Hibernate与Mybatis</h2><p> <strong>1 开发方面</strong></p><p> 在项目开发过程当中，就速度而言：hibernate开发中，sql语句已经被封装，直接可以使用，加快系统开发；Mybatis 属于半自动化，sql需要手工完成，稍微繁琐；但是，凡事都不是绝对的，如果对于庞大复杂的系统项目来说，发杂语句较多，选择hibernate 就不是一个好方案。</p><p> <strong>2 sql优化方面</strong></p><p> Hibernate 自动生成sql,有些语句较为繁琐，会多消耗一些性能；Mybatis 手动编写sql，可以配置动态SQL并优化SQL，可以避免不需要的查询，提高系统性能；</p><p> <strong>3 对象管理比对</strong></p><p> Hibernate 是完整的对象-关系映射的框架，开发工程中，无需过多关注底层实现，只要去管理对象即可；Mybatis 需要自行管理 映射关系；</p><h2 id="快速开始"><a href="#快速开始" class="headerlink" title="快速开始"></a>快速开始</h2><p>1 创建 MyBatis 的配置⽂件 config.xml，⽂件名可⾃定义</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token doctype"><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>configuration</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 配置MyBatis运⾏环境 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>environments</span> <span class="token attr-name">default</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>development<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>environment</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>development<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 配置JDBC事务管理 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>transactionManager</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>JDBC<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>transactionManager</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- POOLED配置JDBC数据源连接池 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dataSource</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>POOLED<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>driver<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.mysql.cj.jdbc.Driver<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>url<span class="token punctuation">"</span></span><span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>jdbc:mysql://localhost:3306/mybatis?useUnicode<span class="token punctuation">=</span>true&amp;characterEncoding<span class="token punctuation">=</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>username<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>root<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>password<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>root<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dataSource</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>environment</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>environments</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>configuration</span><span class="token punctuation">></span></span></code></pre><p>2 自定义sql语句</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8" ?></span><span class="token doctype"><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>mapper</span> <span class="token attr-name">namespace</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.mapper.AccoutMapper<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>insert</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>save<span class="token punctuation">"</span></span> <span class="token attr-name">parameterType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Account<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> insert into t_account(username,password,age) values(#{username},#{password},#{age}) <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>insert</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>mapper</span><span class="token punctuation">></span></span></code></pre><p>namespace 通常设置为⽂件所在包+⽂件名的形式(全限定型类名)。<br>insert 标签表示执⾏添加操作。<br>select 标签表示执⾏查询操作。<br>update 标签表示执⾏更新操作。<br>delete 标签表示执⾏删除操作。<br>id 是实际调⽤ MyBatis ⽅法时需要⽤到的参数，”#{}”表示一个占位符，相当于”?”。<br>parameterType 是调⽤对应⽅法时参数的数据类型，resultType属性用于指定返回结果的类型，</p><p>3 在全局配置⽂件 config.xml 中注册 AccountMapper.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token doctype"><!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>configuration</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 配置MyBatis运⾏环境 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>environments</span> <span class="token attr-name">default</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>development<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>environment</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>development<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 配置JDBC事务管理 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>transactionManager</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>JDBC<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>transactionManager</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- POOLED配置JDBC数据源连接池 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dataSource</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>POOLED<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>driver<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.mysql.cj.jdbc.Driver<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>url<span class="token punctuation">"</span></span><span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>jdbc:mysql://localhost:3306/mybatis?useUnicode<span class="token punctuation">=</span>true&amp;characterEncoding<span class="token punctuation">=</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>username<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>root<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>password<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>root<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dataSource</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>environment</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>environments</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 注册AccountMapper.xml --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>mappers</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>mapper</span> <span class="token attr-name">resource</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com/southwind/mapper/AccountMapper.xml<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>mapper</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>mappers</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>configuration</span><span class="token punctuation">></span></span></code></pre><p>4 调⽤ MyBatis 的原⽣接⼝执⾏添加操作</p><pre class=" language-java"><code class="language-java"><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Test</span> <span class="token punctuation">{</span> <span class="token keyword">public</span> <span class="token keyword">static</span> <span class="token keyword">void</span> <span class="token function">main</span><span class="token punctuation">(</span>String<span class="token punctuation">[</span><span class="token punctuation">]</span> args<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//读取MyBatis配置⽂件</span> InputStream inputStream <span class="token operator">=</span>Test<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">.</span><span class="token function">getClassLoader</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getResourceAsStream</span><span class="token punctuation">(</span><span class="token string">"config.xml"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//根据配置文件生成SqlSessionFactory</span> SqlSessionFactoryBuilder sqlSessionFactoryBuilder <span class="token operator">=</span> <span class="token keyword">new</span><span class="token class-name">SqlSessionFactoryBuilder</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> SqlSessionFactory sqlSessionFactory <span class="token operator">=</span>sqlSessionFactoryBuilder<span class="token punctuation">.</span><span class="token function">build</span><span class="token punctuation">(</span>inputStream<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//通过SqlSessionFactory生成sqlSession</span> SqlSession sqlSession <span class="token operator">=</span> sqlSessionFactory<span class="token punctuation">.</span><span class="token function">openSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> String statement <span class="token operator">=</span> <span class="token string">"com.southwind.mapper.AccoutMapper.save"</span><span class="token punctuation">;</span> Account account <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Account</span><span class="token punctuation">(</span>1L<span class="token punctuation">,</span><span class="token string">"张三"</span><span class="token punctuation">,</span><span class="token string">"123123"</span><span class="token punctuation">,</span><span class="token number">22</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//sqlSession执行映射文件中定义的SQL</span> sqlSession<span class="token punctuation">.</span><span class="token function">insert</span><span class="token punctuation">(</span>statement<span class="token punctuation">,</span>account<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//提交事务</span> sqlSession<span class="token punctuation">.</span><span class="token function">commit</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//关闭sqlSession</span> sqlSession<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><h2 id="Mybatis核心对象"><a href="#Mybatis核心对象" class="headerlink" title="Mybatis核心对象"></a>Mybatis核心对象</h2><p>1 SqlSessionFactory他是单个数据库映射关系经过编译后的内存镜像，主要作用是创建sqlSession；</p><p>SqlSessionFactory对象是安全的，一旦被创建，在整个应用执行期间都会存在，通常一个数据库对应一个SqlSessionFactory，所以构建实例时，一般用单列模式。</p><p>2 sqlSession它是应用程序与持久层执行交互操作的一个单线程对象，主要用于执行持久化操纵。每一个线程都应该有一个自己的sqlSession实例，并且该实例不能被共享，sqlSession实例线程是不安全的，使用后要及时的关闭。</p><h2 id="及连查询"><a href="#及连查询" class="headerlink" title="及连查询"></a>及连查询</h2><h3 id="一对多"><a href="#一对多" class="headerlink" title="一对多"></a>一对多</h3><p>一个班级对应多个学生</p><p>Student</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Data</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Student</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">long</span> id<span class="token punctuation">;</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span> <span class="token keyword">private</span> Classes classes<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>classes</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Data</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Classes</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">long</span> id<span class="token punctuation">;</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span> <span class="token keyword">private</span> List<span class="token operator"><</span>Student<span class="token operator">></span> students<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>student.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8" ?></span><span class="token doctype"><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>mapper</span> <span class="token attr-name">namespace</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.repository.StudentRepository<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>resultMap</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>studentMap<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>id</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>result</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>association</span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>classes<span class="token punctuation">"</span></span> <span class="token attr-name">javaType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Classes<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cid<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>id</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cname<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>result</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>association</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>resultMap</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>findById<span class="token punctuation">"</span></span> <span class="token attr-name">parameterType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>long<span class="token punctuation">"</span></span> <span class="token attr-name">resultMap</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>studentMap<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> select s.id,s.name,c.id as cid,c.name as cname from student s,classes cwhere s.id = #{id} and s.cid = c.id <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>select</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>mapper</span><span class="token punctuation">></span></span></code></pre><p>class.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8" ?></span><span class="token doctype"><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>mapper</span> <span class="token attr-name">namespace</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.repository.ClassesRepository<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>resultMap</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>classesMap<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Classes<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cid<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>id</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cname<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>result</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>collection</span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>students<span class="token punctuation">"</span></span> <span class="token attr-name">ofType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>collection</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>resultMap</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>findById<span class="token punctuation">"</span></span> <span class="token attr-name">parameterType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>long<span class="token punctuation">"</span></span> <span class="token attr-name">resultMap</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>classesMap<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> select s.id,s.name,c.id as cid,c.name as cname from student s,classes cwhere c.id = #{id} and s.cid = c.id <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>select</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>mapper</span><span class="token punctuation">></span></span></code></pre><p>association可以配置以下属性</p><p>property：指定映射到实体类对象属性，与表字段一一对应</p><p>column：指定表中对应的字段</p><p>javaType：指定映射到实体对象属性的类型</p><h3 id="多对多"><a href="#多对多" class="headerlink" title="多对多"></a>多对多</h3><p>多个顾客对应多个商品</p><p>Customer</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Data</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Customer</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">long</span> id<span class="token punctuation">;</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span> <span class="token keyword">private</span> List<span class="token operator"><</span>Goods<span class="token operator">></span> goods<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>Goods</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Data</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Goods</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">long</span> id<span class="token punctuation">;</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span> <span class="token keyword">private</span> List<span class="token operator"><</span>Customer<span class="token operator">></span> customers<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>customer.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8" ?></span><span class="token doctype"><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>mapper</span> <span class="token attr-name">namespace</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.repository.CustomerRepository<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>resultMap</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>customerMap<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Customer<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cid<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>id</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cname<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>result</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>collection</span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>goods<span class="token punctuation">"</span></span> <span class="token attr-name">ofType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Goods<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>gid<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>gname<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>collection</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>resultMap</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>findById<span class="token punctuation">"</span></span> <span class="token attr-name">parameterType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>long<span class="token punctuation">"</span></span> <span class="token attr-name">resultMap</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>customerMap<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> select c.id cid,c.name cname,g.id gid,g.name gname from customer c,goodsg,customer_goods cg where c.id = #{id} and cg.cid = c.id and cg.gid = g.id <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>select</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>mapper</span><span class="token punctuation">></span></span></code></pre><p>goods.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8" ?></span><span class="token doctype"><!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>mapper</span> <span class="token attr-name">namespace</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.repository.GoodsRepository<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>resultMap</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>goodsMap<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Goods<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>gid<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>id</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>gname<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>result</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>collection</span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>customers<span class="token punctuation">"</span></span> <span class="token attr-name">ofType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Customer<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cid<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cname<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>collection</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>resultMap</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>findById<span class="token punctuation">"</span></span> <span class="token attr-name">parameterType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>long<span class="token punctuation">"</span></span> <span class="token attr-name">resultMap</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>goodsMap<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> select c.id cid,c.name cname,g.id gid,g.name gname from customer c,goodsg,customer_goods cg where g.id = #{id} and cg.cid = c.id and cg.gid = g.id <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>select</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>mapper</span><span class="token punctuation">></span></span></code></pre><h2 id="MyBatis-延迟加载"><a href="#MyBatis-延迟加载" class="headerlink" title="MyBatis 延迟加载"></a>MyBatis 延迟加载</h2><p>什么是延迟加载？<br>延迟加载也叫懒加载、惰性加载，使⽤延迟加载可以提⾼程序的运⾏效率，针对于数据持久层的操作，<br>在某些特定的情况下去访问特定的数据库，在其他情况下可以不访问某些表，从⼀定程度上减少了 Java<br>应⽤与数据库的交互次数。<br>查询学⽣和班级的时，学⽣和班级是两张不同的表，如果当前需求只需要获取学⽣的信息，那么查询学<br>⽣单表即可，如果需要通过学⽣获取对应的班级信息，则必须查询两张表。<br>不同的业务需求，需要查询不同的表，根据具体的业务需求来动态减少数据表查询的⼯作就是延迟加<br>载。</p><p>在 config.xml 中开启延迟加载</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>settings</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 打印SQL--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>setting</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>logImpl<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>STDOUT_LOGGING<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token comment" spellcheck="true"><!-- 开启延迟加载 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>setting</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>lazyLoadingEnabled<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>true<span class="token punctuation">"</span></span><span class="token punctuation">/></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>settings</span><span class="token punctuation">></span></span></code></pre><p>student.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>resultMap</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>studentMapLazy<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>id</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>id</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>result</span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>result</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>association</span> <span class="token attr-name">property</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>classes<span class="token punctuation">"</span></span> <span class="token attr-name">javaType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Classes<span class="token punctuation">"</span></span><span class="token attr-name">select</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.repository.ClassesRepository.findByIdLazy<span class="token punctuation">"</span></span> <span class="token attr-name">column</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cid<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>association</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>resultMap</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>findByIdLazy<span class="token punctuation">"</span></span> <span class="token attr-name">parameterType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>long<span class="token punctuation">"</span></span> <span class="token attr-name">resultMap</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>studentMapLazy<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> select * from student where id = #{id}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>select</span><span class="token punctuation">></span></span></code></pre><p>class.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>findByIdLazy<span class="token punctuation">"</span></span> <span class="token attr-name">parameterType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>long<span class="token punctuation">"</span></span> <span class="token attr-name">resultType</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Classes<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> select * from classes where id = #{id}<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>select</span><span class="token punctuation">></span></span></code></pre><p>MyBatis缓存</p><p>什么是 MyBatis 缓存<br>使⽤缓存可以减少 Java 应⽤与数据库的交互次数，从⽽提升程序的运⾏效率。⽐如查询出 id = 1 的对<br>象，第⼀次查询出之后会⾃动将该对象保存到缓存中，当下⼀次查询时，直接从缓存中取出对象即可，<br>⽆需再次访问数据库。<br>MyBatis 缓存分类</p><p>1、⼀级缓存：SqlSession 级别，默认开启，并且不能关闭。<br>操作数据库时需要创建 SqlSession 对象，在对象中有⼀个 HashMap ⽤于存储缓存数据，不同的<br>SqlSession 之间缓存数据区域是互不影响的。<br>⼀级缓存的作⽤域是 SqlSession 范围的，当在同⼀个 SqlSession 中执⾏两次相同的 SQL 语句事，第⼀<br>次执⾏完毕会将结果保存到缓存中，第⼆次查询时直接从缓存中获取。<br>需要注意的是，如果 SqlSession 执⾏了 DML 操作（insert、update、delete），MyBatis 必须将缓存<br>清空以保证数据的准确性。<br>2、⼆级缓存：Mapper 级别，默认关闭，可以开启。</p><p>使⽤⼆级缓存时，多个 SqlSession 使⽤同⼀个 Mapper 的 SQL 语句操作数据库，得到的数据会存在⼆<br>级缓存区，同样是使⽤ HashMap 进⾏数据存储，相⽐较于⼀级缓存，⼆级缓存的范围更⼤，多个<br>SqlSession 可以共⽤⼆级缓存，⼆级缓存是跨 SqlSession 的。<br>⼆级缓存是多个 SqlSession 共享的，其作⽤域是 Mapper 的同⼀个 namespace，不同的 SqlSession<br>两次执⾏相同的 namespace 下的 SQL 语句，参数也相等，则第⼀次执⾏成功之后会将数据保存到⼆级<br>缓存中，第⼆次可直接从⼆级缓存中取出数据</p><h2 id="动态sql"><a href="#动态sql" class="headerlink" title="动态sql"></a>动态sql</h2><p>foreach 标签<br>foreach标签主要有以下参数：<br>item ：循环体中的具体对象。支持属性的点路径访问，如item.age,item.info.details，在list和数组中是其中的对象，在map中是value。<br>index ：在list和数组中,index是元素的序号，在map中，index是元素的key，该参数可选。<br>open ：表示该语句以什么开始<br>close ：表示该语句以什么结束<br>separator ：表示元素之间的分隔符，例如在in()的时候，separator=”,”会自动在元素中间用“,“隔开，避免手动输入逗号导致sql错误，如in(1,2,)这样。该参数可选。</p><pre class=" language-xml"><code class="language-xml"><span class="token comment" spellcheck="true"><!--动态Sql: foreach标签, 批量插入--></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>insert</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>dynamicSqlInsertList<span class="token punctuation">"</span></span> <span class="token attr-name">useGeneratedKeys</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>true<span class="token punctuation">"</span></span> <span class="token attr-name">keyProperty</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> insert into users (name, age, county, date) values <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>foreach</span> <span class="token attr-name">collection</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>list<span class="token punctuation">"</span></span> <span class="token attr-name">item</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>user<span class="token punctuation">"</span></span> <span class="token attr-name">separator</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>,<span class="token punctuation">"</span></span> <span class="token punctuation">></span></span> (#{user.name}, #{user.age}, #{user.county}, #{user.date}) <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>foreach</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>insert</span><span class="token punctuation">></span></span></code></pre>]]></content>
<tags>
<tag> mybatis </tag>
</tags>
</entry>
<entry>
<title>spring简述</title>
<link href="2021/06/06/spring-jian-shu/"/>
<url>2021/06/06/spring-jian-shu/</url>
<content type="html"><![CDATA[<h3 id="Spring-框架两大核心机制（IoC、AOP）"><a href="#Spring-框架两大核心机制（IoC、AOP）" class="headerlink" title="Spring 框架两大核心机制（IoC、AOP）"></a>Spring 框架两大核心机制（IoC、AOP）</h3><ul><li>IoC（控制反转）/ DI（依赖注入）</li><li>AOP（面向切面编程）</li></ul><p>Spring 是一个企业级开发框架，是软件设计层面的框架，优势在于可以将应用程序进行分层，开发者可以自主选择组件。</p><p>MVC：Struts2、Spring MVC</p><p>ORMapping：Hibernate、MyBatis、Spring Data</p><h3 id="如何使用-IoC"><a href="#如何使用-IoC" class="headerlink" title="如何使用 IoC"></a>如何使用 IoC</h3><ul><li>创建 Maven 工程，pom.xml 添加依赖</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>project</span> <span class="token attr-name">xmlns</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://maven.apache.org/POM/4.0.0<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>xsi</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.w3.org/2001/XMLSchema-instance<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xsi:</span>schemaLocation</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>modelVersion</span><span class="token punctuation">></span></span>4.0.0<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>modelVersion</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>com.southwind<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>aispringioc<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>1.0-SNAPSHOT<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependencies</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.springframework<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>spring-context<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>5.0.11.RELEASE<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependencies</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>project</span><span class="token punctuation">></span></span></code></pre><ul><li>创建实体类 Student</li></ul><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>entity<span class="token punctuation">;</span><span class="token keyword">import</span> lombok<span class="token punctuation">.</span>Data<span class="token punctuation">;</span><span class="token annotation punctuation">@Data</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Student</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">long</span> id<span class="token punctuation">;</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span> <span class="token keyword">private</span> <span class="token keyword">int</span> age<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><ul><li>传统的开发方式，手动 new Student</li></ul><pre class=" language-java"><code class="language-java">Student student <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">Student</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>student<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span>student<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>student<span class="token punctuation">.</span><span class="token function">setAge</span><span class="token punctuation">(</span><span class="token number">22</span><span class="token punctuation">)</span><span class="token punctuation">;</span>System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>student<span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre><ul><li>通过 IoC 创建对象，在配置文件中添加需要管理的对象，XML 格式的配置文件，文件名可以自定义。</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>beans</span> <span class="token attr-name">xmlns</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>xsi</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.w3.org/2001/XMLSchema-instance<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>context</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/context<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>p</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/p<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xsi:</span>schemaLocation</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>张三<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>age<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>22<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>beans</span><span class="token punctuation">></span></span></code></pre><ul><li>从 IoC 中获取对象，通过 id 获取。</li></ul><pre class=" language-java"><code class="language-java"><span class="token comment" spellcheck="true">//加载配置文件</span>ApplicationContext applicationContext <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ClassPathXmlApplicationContext</span><span class="token punctuation">(</span><span class="token string">"spring.xml"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>Student student <span class="token operator">=</span> <span class="token punctuation">(</span>Student<span class="token punctuation">)</span> applicationContext<span class="token punctuation">.</span><span class="token function">getBean</span><span class="token punctuation">(</span><span class="token string">"student"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>student<span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre><h3 id="配置文件"><a href="#配置文件" class="headerlink" title="配置文件"></a>配置文件</h3><ul><li><p>通过配置 <code>bean</code> 标签来完成对象的管理。</p><ul><li><code>id</code>：对象名。</li><li><code>class</code>：对象的模版类（所有交给 IoC 容器来管理的类必须有无参构造函数，因为 Spring 底层是通过反射机制来创建对象，调用的是无参构造）</li></ul></li><li><p>对象的成员变量通过 <code>property</code> 标签完成赋值。</p><ul><li><code>name</code>：成员变量名。</li><li><code>value</code>：成员变量值（基本数据类型，String 可以直接赋值，如果是其他引用类型，不能通过 value 赋值）</li><li><code>ref</code>：将 IoC 中的另外一个 bean 赋给当前的成员变量（DI）</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>张三<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>age<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>22<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span> <span class="token attr-name">ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>科技路<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre></li></ul><h3 id="IoC-底层原理"><a href="#IoC-底层原理" class="headerlink" title="IoC 底层原理"></a>IoC 底层原理</h3><ul><li>读取配置文件，解析 XML。</li><li>通过反射机制实例化配置文件中所配置所有的 bean。</li></ul><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>ioc<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>dom4j<span class="token punctuation">.</span>Document<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>dom4j<span class="token punctuation">.</span>DocumentException<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>dom4j<span class="token punctuation">.</span>Element<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>dom4j<span class="token punctuation">.</span>io<span class="token punctuation">.</span>SAXReader<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>reflect<span class="token punctuation">.</span>Constructor<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>reflect<span class="token punctuation">.</span>Field<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>reflect<span class="token punctuation">.</span>InvocationTargetException<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>reflect<span class="token punctuation">.</span>Method<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>HashMap<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Iterator<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Map<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">ClassPathXmlApplicationContext</span> <span class="token keyword">implements</span> <span class="token class-name">ApplicationContext</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> Map<span class="token operator"><</span>String<span class="token punctuation">,</span>Object<span class="token operator">></span> ioc <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token operator"><</span>String<span class="token punctuation">,</span> Object<span class="token operator">></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">public</span> <span class="token function">ClassPathXmlApplicationContext</span><span class="token punctuation">(</span>String path<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">try</span> <span class="token punctuation">{</span> SAXReader reader <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">SAXReader</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> Document document <span class="token operator">=</span> reader<span class="token punctuation">.</span><span class="token function">read</span><span class="token punctuation">(</span><span class="token string">"./src/main/resources/"</span><span class="token operator">+</span>path<span class="token punctuation">)</span><span class="token punctuation">;</span> Element root <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">getRootElement</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> Iterator<span class="token operator"><</span>Element<span class="token operator">></span> iterator <span class="token operator">=</span> root<span class="token punctuation">.</span><span class="token function">elementIterator</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">while</span><span class="token punctuation">(</span>iterator<span class="token punctuation">.</span><span class="token function">hasNext</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> Element element <span class="token operator">=</span> iterator<span class="token punctuation">.</span><span class="token function">next</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> String id <span class="token operator">=</span> element<span class="token punctuation">.</span><span class="token function">attributeValue</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> String className <span class="token operator">=</span> element<span class="token punctuation">.</span><span class="token function">attributeValue</span><span class="token punctuation">(</span><span class="token string">"class"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//通过反射机制创建对象</span> Class <span class="token class-name">clazz</span> <span class="token operator">=</span> Class<span class="token punctuation">.</span><span class="token function">forName</span><span class="token punctuation">(</span>className<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//获取无参构造函数，创建目标对象</span> Constructor constructor <span class="token operator">=</span> clazz<span class="token punctuation">.</span><span class="token function">getConstructor</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> Object object <span class="token operator">=</span> constructor<span class="token punctuation">.</span><span class="token function">newInstance</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//给目标对象赋值</span> Iterator<span class="token operator"><</span>Element<span class="token operator">></span> beanIter <span class="token operator">=</span> element<span class="token punctuation">.</span><span class="token function">elementIterator</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">while</span><span class="token punctuation">(</span>beanIter<span class="token punctuation">.</span><span class="token function">hasNext</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> Element property <span class="token operator">=</span> beanIter<span class="token punctuation">.</span><span class="token function">next</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> String name <span class="token operator">=</span> property<span class="token punctuation">.</span><span class="token function">attributeValue</span><span class="token punctuation">(</span><span class="token string">"name"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> String valueStr <span class="token operator">=</span> property<span class="token punctuation">.</span><span class="token function">attributeValue</span><span class="token punctuation">(</span><span class="token string">"value"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> String ref <span class="token operator">=</span> property<span class="token punctuation">.</span><span class="token function">attributeValue</span><span class="token punctuation">(</span><span class="token string">"ref"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">if</span><span class="token punctuation">(</span>ref <span class="token operator">==</span> null<span class="token punctuation">)</span><span class="token punctuation">{</span> String methodName <span class="token operator">=</span> <span class="token string">"set"</span><span class="token operator">+</span>name<span class="token punctuation">.</span><span class="token function">substring</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">,</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">toUpperCase</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">+</span>name<span class="token punctuation">.</span><span class="token function">substring</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span> Field field <span class="token operator">=</span> clazz<span class="token punctuation">.</span><span class="token function">getDeclaredField</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> Method method <span class="token operator">=</span> clazz<span class="token punctuation">.</span><span class="token function">getDeclaredMethod</span><span class="token punctuation">(</span>methodName<span class="token punctuation">,</span>field<span class="token punctuation">.</span><span class="token function">getType</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//根据成员变量的数据类型将 value 进行转换</span> Object value <span class="token operator">=</span> null<span class="token punctuation">;</span> <span class="token keyword">if</span><span class="token punctuation">(</span>field<span class="token punctuation">.</span><span class="token function">getType</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">==</span> <span class="token string">"long"</span><span class="token punctuation">)</span><span class="token punctuation">{</span> value <span class="token operator">=</span> Long<span class="token punctuation">.</span><span class="token function">parseLong</span><span class="token punctuation">(</span>valueStr<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">if</span><span class="token punctuation">(</span>field<span class="token punctuation">.</span><span class="token function">getType</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">==</span> <span class="token string">"java.lang.String"</span><span class="token punctuation">)</span><span class="token punctuation">{</span> value <span class="token operator">=</span> valueStr<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">if</span><span class="token punctuation">(</span>field<span class="token punctuation">.</span><span class="token function">getType</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">==</span> <span class="token string">"int"</span><span class="token punctuation">)</span><span class="token punctuation">{</span> value <span class="token operator">=</span> Integer<span class="token punctuation">.</span><span class="token function">parseInt</span><span class="token punctuation">(</span>valueStr<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> method<span class="token punctuation">.</span><span class="token function">invoke</span><span class="token punctuation">(</span>object<span class="token punctuation">,</span>value<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> ioc<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>id<span class="token punctuation">,</span>object<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">DocumentException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">ClassNotFoundException</span> e<span class="token punctuation">)</span><span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">NoSuchMethodException</span> e<span class="token punctuation">)</span><span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">InstantiationException</span> e<span class="token punctuation">)</span><span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IllegalAccessException</span> e<span class="token punctuation">)</span><span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">InvocationTargetException</span> e<span class="token punctuation">)</span><span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">NoSuchFieldException</span> e<span class="token punctuation">)</span><span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> Object <span class="token function">getBean</span><span class="token punctuation">(</span>String id<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">return</span> ioc<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><h3 id="通过运行时类获取-bean"><a href="#通过运行时类获取-bean" class="headerlink" title="通过运行时类获取 bean"></a>通过运行时类获取 bean</h3><pre class=" language-java"><code class="language-java">ApplicationContext applicationContext <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ClassPathXmlApplicationContext</span><span class="token punctuation">(</span><span class="token string">"spring.xml"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>Student student <span class="token operator">=</span> <span class="token punctuation">(</span>Student<span class="token punctuation">)</span> applicationContext<span class="token punctuation">.</span><span class="token function">getBean</span><span class="token punctuation">(</span>Student<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">)</span><span class="token punctuation">;</span>System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>student<span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre><p>这种方式存在一个问题，配置文件中一个数据类型的对象只能有一个实例，否则会抛出异常，因为没有唯一的 bean。</p><h3 id="通过有参构造创建-bean"><a href="#通过有参构造创建-bean" class="headerlink" title="通过有参构造创建 bean"></a>通过有参构造创建 bean</h3><ul><li>在实体类中创建对应的有参构造函数。</li><li>配置文件</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student3<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>3<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>小明<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>age<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>18<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span> <span class="token attr-name">ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student3<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">index</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>3<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">index</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>2<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>18<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">index</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>小明<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">index</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>3<span class="token punctuation">"</span></span> <span class="token attr-name">ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><h3 id="给-bean-注入集合"><a href="#给-bean-注入集合" class="headerlink" title="给 bean 注入集合"></a>给 bean 注入集合</h3><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>2<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>李四<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>age<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>33<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>addresses<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>list</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ref</span> <span class="token attr-name">bean</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ref</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ref</span> <span class="token attr-name">bean</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address2<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ref</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>list</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>科技路<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address2<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>2<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>高新区<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><h3 id="scope-作用域"><a href="#scope-作用域" class="headerlink" title="scope 作用域"></a>scope 作用域</h3><p>Spring 管理的 bean 是根据 scope 来生成的，表示 bean 的作用域，共4种，默认值是 singleton。</p><ul><li>singleton：单例，表示通过 IoC 容器获取的 bean 是唯一的。</li><li>prototype：原型，表示通过 IoC 容器获取的 bean 是不同的。</li><li>request：请求，表示在一次 HTTP 请求内有效。</li><li>session：回话，表示在一个用户会话内有效。</li></ul><p>request 和 session 只适用于 Web 项目，大多数情况下，使用单例和原型较多。</p><p>prototype 模式当业务代码获取 IoC 容器中的 bean 时，Spring 才去调用无参构造创建对应的 bean。</p><p>singleton 模式无论业务代码是否获取 IoC 容器中的 bean，Spring 在加载 spring.xml 时就会创建 bean。</p><h3 id="Spring-的继承"><a href="#Spring-的继承" class="headerlink" title="Spring 的继承"></a>Spring 的继承</h3><p>与 Java 的继承不同，Java 是类层面的继承，子类可以继承父类的内部结构信息；Spring 是对象层面的继承，子对象可以继承父对象的属性值。</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student2<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>张三<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>age<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>22<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>addresses<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>list</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ref</span> <span class="token attr-name">bean</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ref</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>ref</span> <span class="token attr-name">bean</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address2<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>ref</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>list</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>科技路<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address2<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>2<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>高新区<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>stu<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span> <span class="token attr-name">parent</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student2<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>李四<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><p>Spring 的继承关注点在于具体的对象，而不在于类，即不同的两个类的实例化对象可以完成继承，前提是子对象必须包含父对象的所有属性，同时可以在此基础上添加其他的属性。</p><h3 id="Spring-的依赖"><a href="#Spring-的依赖" class="headerlink" title="Spring 的依赖"></a>Spring 的依赖</h3><p>与继承类似，依赖也是描述 bean 和 bean 之间的一种关系，配置依赖之后，被依赖的 bean 一定先创建，再创建依赖的 bean，A 依赖于 B，先创建 B，再创建 A。</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>beans</span> <span class="token attr-name">xmlns</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>xsi</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.w3.org/2001/XMLSchema-instance<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xsi:</span>schemaLocation</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd <span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span> <span class="token attr-name">depends-on</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>user<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>user<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.User<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>beans</span><span class="token punctuation">></span></span></code></pre><h3 id="Spring-的-p-命名空间"><a href="#Spring-的-p-命名空间" class="headerlink" title="Spring 的 p 命名空间"></a>Spring 的 p 命名空间</h3><p>p 命名空间是对 IoC / DI 的简化操作，使用 p 命名空间可以更加方便的完成 bean 的配置以及 bean 之间的依赖注入。</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>beans</span> <span class="token attr-name">xmlns</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>xsi</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.w3.org/2001/XMLSchema-instance<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>context</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/context<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>p</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/p<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xsi:</span>schemaLocation</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>student<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Student<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">p:</span>id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">p:</span>name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>张三<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">p:</span>age</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>22<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">p:</span>address-ref</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>address<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Address<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">p:</span>id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>2<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">p:</span>name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>科技路<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>beans</span><span class="token punctuation">></span></span></code></pre><h3 id="Spring-的工厂方法"><a href="#Spring-的工厂方法" class="headerlink" title="Spring 的工厂方法"></a>Spring 的工厂方法</h3><p>IoC 通过工厂模式创建 bean 的方式有两种：</p><ul><li>静态工厂方法</li><li>实例工厂方法</li></ul><blockquote><p>静态工厂方法</p></blockquote><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>entity<span class="token punctuation">;</span><span class="token keyword">import</span> lombok<span class="token punctuation">.</span>AllArgsConstructor<span class="token punctuation">;</span><span class="token keyword">import</span> lombok<span class="token punctuation">.</span>Data<span class="token punctuation">;</span><span class="token keyword">import</span> lombok<span class="token punctuation">.</span>NoArgsConstructor<span class="token punctuation">;</span><span class="token annotation punctuation">@Data</span><span class="token annotation punctuation">@AllArgsConstructor</span><span class="token annotation punctuation">@NoArgsConstructor</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Car</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">long</span> id<span class="token punctuation">;</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>factory<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>entity<span class="token punctuation">.</span>Car<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>HashMap<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Map<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">StaticCarFactory</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">static</span> Map<span class="token operator"><</span>Long<span class="token punctuation">,</span> Car<span class="token operator">></span> carMap<span class="token punctuation">;</span> <span class="token keyword">static</span><span class="token punctuation">{</span> carMap <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token operator"><</span>Long<span class="token punctuation">,</span> Car<span class="token operator">></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> carMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>1L<span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Car</span><span class="token punctuation">(</span>1L<span class="token punctuation">,</span><span class="token string">"宝马"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> carMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>2L<span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Car</span><span class="token punctuation">(</span>2L<span class="token punctuation">,</span><span class="token string">"奔驰"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> <span class="token keyword">static</span> Car <span class="token function">getCar</span><span class="token punctuation">(</span><span class="token keyword">long</span> id<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> carMap<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><pre class=" language-xml"><code class="language-xml"><span class="token comment" spellcheck="true"><!-- 配置静态工厂创建 Car --></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>car<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.factory.StaticCarFactory<span class="token punctuation">"</span></span> <span class="token attr-name">factory-method</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>getCar<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>2<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><blockquote><p>实例工厂方法</p></blockquote><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>factory<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>entity<span class="token punctuation">.</span>Car<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>HashMap<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Map<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">InstanceCarFactory</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> Map<span class="token operator"><</span>Long<span class="token punctuation">,</span> Car<span class="token operator">></span> carMap<span class="token punctuation">;</span> <span class="token keyword">public</span> <span class="token function">InstanceCarFactory</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> carMap <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token operator"><</span>Long<span class="token punctuation">,</span> Car<span class="token operator">></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> carMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>1L<span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Car</span><span class="token punctuation">(</span>1L<span class="token punctuation">,</span><span class="token string">"宝马"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> carMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>2L<span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Car</span><span class="token punctuation">(</span>2L<span class="token punctuation">,</span><span class="token string">"奔驰"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> Car <span class="token function">getCar</span><span class="token punctuation">(</span><span class="token keyword">long</span> id<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> carMap<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><pre class=" language-xml"><code class="language-xml"><span class="token comment" spellcheck="true"><!-- 配置实例工厂 bean --></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>carFactory<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.factory.InstanceCarFactory<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token comment" spellcheck="true"><!-- 赔偿实例工厂创建 Car --></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>car2<span class="token punctuation">"</span></span> <span class="token attr-name">factory-bean</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>carFactory<span class="token punctuation">"</span></span> <span class="token attr-name">factory-method</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>getCar<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>constructor-arg</span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>constructor-arg</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><h3 id="IoC-自动装载（Autowire）"><a href="#IoC-自动装载（Autowire）" class="headerlink" title="IoC 自动装载（Autowire）"></a>IoC 自动装载（Autowire）</h3><p>IoC 负责创建对象，DI 负责完成对象的依赖注入，通过配置 property 标签的 ref 属性来完成，同时 Spring 提供了另外一种更加简便的依赖注入方式：自动装载，不需要手动配置 property，IoC 容器会自动选择 bean 完成注入。</p><p>自动装载有两种方式：</p><ul><li>byName：通过属性名自动装载</li><li>byType：通过属性的数据类型自动装载</li></ul><blockquote><p>byName</p></blockquote><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>cars<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Car<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>宝马<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>person<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Person<span class="token punctuation">"</span></span> <span class="token attr-name">autowire</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>byName<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>11<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>张三<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><blockquote><p>byType</p></blockquote><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>car<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Car<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>2<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>奔驰<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>person<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind.entity.Person<span class="token punctuation">"</span></span> <span class="token attr-name">autowire</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>byType<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>id<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>11<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>name<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>张三<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><p>byType 需要注意，如果同时存在两个及以上的符合条件的 bean 时，自动装载会抛出异常。</p><h3 id="AOP"><a href="#AOP" class="headerlink" title="AOP"></a>AOP</h3><p>AOP：Aspect Oriented Programming 面向切面编程。</p><p>AOP 的优点：</p><ul><li>降低模块之间的耦合度。</li><li>使系统更容易扩展。</li><li>更好的代码复用。</li><li>非业务代码更加集中，不分散，便于统一管理。</li><li>业务代码更加简洁存粹，不参杂其他代码的影响。</li></ul><p>AOP 是对面向对象编程的一个补充，在运行时，动态地将代码切入到类的指定方法、指定位置上的编程思想就是面向切面编程。将不同方法的同一个位置抽象成一个切面对象，对该切面对象进行编程就是 AOP。</p><h3 id="如何使用？"><a href="#如何使用？" class="headerlink" title="如何使用？"></a>如何使用？</h3><ul><li>创建 Maven 工程，pom.xml 添加</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependencies</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.springframework<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>spring-context<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>5.0.11.RELEASE<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.springframework<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>spring-aop<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>5.0.11.RELEASE<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.springframework<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>spring-aspects<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>5.0.11.RELEASE<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependencies</span><span class="token punctuation">></span></span></code></pre><ul><li>创建一个计算器接口 Cal，定义4个方法。</li></ul><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>utils<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">interface</span> <span class="token class-name">Cal</span> <span class="token punctuation">{</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">add</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span><span class="token keyword">int</span> num2<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">sub</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span><span class="token keyword">int</span> num2<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">mul</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span><span class="token keyword">int</span> num2<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">div</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span><span class="token keyword">int</span> num2<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><ul><li>创建接口的实现类 CalImpl。</li></ul><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>utils<span class="token punctuation">.</span>impl<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>utils<span class="token punctuation">.</span>Cal<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">CalImpl</span> <span class="token keyword">implements</span> <span class="token class-name">Cal</span> <span class="token punctuation">{</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">add</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span> <span class="token keyword">int</span> num2<span class="token punctuation">)</span> <span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"add方法的参数是["</span><span class="token operator">+</span>num1<span class="token operator">+</span><span class="token string">","</span><span class="token operator">+</span>num2<span class="token operator">+</span><span class="token string">"]"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">int</span> result <span class="token operator">=</span> num1<span class="token operator">+</span>num2<span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"add方法的结果是"</span><span class="token operator">+</span>result<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">sub</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span> <span class="token keyword">int</span> num2<span class="token punctuation">)</span> <span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"sub方法的参数是["</span><span class="token operator">+</span>num1<span class="token operator">+</span><span class="token string">","</span><span class="token operator">+</span>num2<span class="token operator">+</span><span class="token string">"]"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">int</span> result <span class="token operator">=</span> num1<span class="token operator">-</span>num2<span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"sub方法的结果是"</span><span class="token operator">+</span>result<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">mul</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span> <span class="token keyword">int</span> num2<span class="token punctuation">)</span> <span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"mul方法的参数是["</span><span class="token operator">+</span>num1<span class="token operator">+</span><span class="token string">","</span><span class="token operator">+</span>num2<span class="token operator">+</span><span class="token string">"]"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">int</span> result <span class="token operator">=</span> num1<span class="token operator">*</span>num2<span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"mul方法的结果是"</span><span class="token operator">+</span>result<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">div</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span> <span class="token keyword">int</span> num2<span class="token punctuation">)</span> <span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"div方法的参数是["</span><span class="token operator">+</span>num1<span class="token operator">+</span><span class="token string">","</span><span class="token operator">+</span>num2<span class="token operator">+</span><span class="token string">"]"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">int</span> result <span class="token operator">=</span> num1<span class="token operator">/</span>num2<span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"div方法的结果是"</span><span class="token operator">+</span>result<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>上述代码中，日志信息和业务逻辑的耦合性很高，不利于系统的维护，使用 AOP 可以进行优化，如何来实现 AOP？使用动态代理的方式来实现。</p><p>给业务代码找一个代理，打印日志信息的工作交个代理来做，这样的话业务代码就只需要关注自身的业务即可。</p><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>utils<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>reflect<span class="token punctuation">.</span>InvocationHandler<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>reflect<span class="token punctuation">.</span>Method<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>reflect<span class="token punctuation">.</span>Proxy<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Arrays<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">MyInvocationHandler</span> <span class="token keyword">implements</span> <span class="token class-name">InvocationHandler</span> <span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//接收委托对象</span> <span class="token keyword">private</span> Object object <span class="token operator">=</span> null<span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//返回代理对象</span> <span class="token keyword">public</span> Object <span class="token function">bind</span><span class="token punctuation">(</span>Object object<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">this</span><span class="token punctuation">.</span>object <span class="token operator">=</span> object<span class="token punctuation">;</span> <span class="token keyword">return</span> Proxy<span class="token punctuation">.</span><span class="token function">newProxyInstance</span><span class="token punctuation">(</span>object<span class="token punctuation">.</span><span class="token function">getClass</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getClassLoader</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span>object<span class="token punctuation">.</span><span class="token function">getClass</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getInterfaces</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span><span class="token keyword">this</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> Object <span class="token function">invoke</span><span class="token punctuation">(</span>Object proxy<span class="token punctuation">,</span> Method method<span class="token punctuation">,</span> Object<span class="token punctuation">[</span><span class="token punctuation">]</span> args<span class="token punctuation">)</span> <span class="token keyword">throws</span> Throwable <span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>method<span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">+</span><span class="token string">"方法的参数是："</span><span class="token operator">+</span> Arrays<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span>args<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> Object result <span class="token operator">=</span> method<span class="token punctuation">.</span><span class="token function">invoke</span><span class="token punctuation">(</span><span class="token keyword">this</span><span class="token punctuation">.</span>object<span class="token punctuation">,</span>args<span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>method<span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">+</span><span class="token string">"的结果是"</span><span class="token operator">+</span>result<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>以上是通过动态代理实现 AOP 的过程，比较复杂，不好理解，Spring 框架对 AOP 进行了封装，使用 Spring 框架可以用面向对象的思想来实现 AOP。</p><p>Spring 框架中不需要创建 InvocationHandler，只需要创建一个切面对象，将所有的非业务代码在切面对象中完成即可，Spring 框架底层会自动根据切面类以及目标类生成一个代理对象。</p><p>LoggerAspect</p><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>aop<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>aspectj<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>JoinPoint<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>aspectj<span class="token punctuation">.</span>lang<span class="token punctuation">.</span>annotation<span class="token punctuation">.</span>*<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>stereotype<span class="token punctuation">.</span>Component<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Arrays<span class="token punctuation">;</span><span class="token annotation punctuation">@Aspect</span><span class="token annotation punctuation">@Component</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">LoggerAspect</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Before</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"execution(public int com.southwind.utils.impl.CalImpl.*(..))"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">before</span><span class="token punctuation">(</span>JoinPoint joinPoint<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//获取方法名</span> String name <span class="token operator">=</span> joinPoint<span class="token punctuation">.</span><span class="token function">getSignature</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//获取参数</span> String args <span class="token operator">=</span> Arrays<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span>joinPoint<span class="token punctuation">.</span><span class="token function">getArgs</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>name<span class="token operator">+</span><span class="token string">"方法的参数是："</span><span class="token operator">+</span> args<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@After</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"execution(public int com.southwind.utils.impl.CalImpl.*(..))"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">after</span><span class="token punctuation">(</span>JoinPoint joinPoint<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//获取方法名</span> String name <span class="token operator">=</span> joinPoint<span class="token punctuation">.</span><span class="token function">getSignature</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>name<span class="token operator">+</span><span class="token string">"方法执行完毕"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@AfterReturning</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"execution(public int com.southwind.utils.impl.CalImpl.*(..))"</span><span class="token punctuation">,</span>returning <span class="token operator">=</span> <span class="token string">"result"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">afterReturning</span><span class="token punctuation">(</span>JoinPoint joinPoint<span class="token punctuation">,</span>Object result<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//获取方法名</span> String name <span class="token operator">=</span> joinPoint<span class="token punctuation">.</span><span class="token function">getSignature</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>name<span class="token operator">+</span><span class="token string">"方法的结果是"</span><span class="token operator">+</span>result<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@AfterThrowing</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"execution(public int com.southwind.utils.impl.CalImpl.*(..))"</span><span class="token punctuation">,</span>throwing <span class="token operator">=</span> <span class="token string">"exception"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">afterThrowing</span><span class="token punctuation">(</span>JoinPoint joinPoint<span class="token punctuation">,</span>Exception exception<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//获取方法名</span> String name <span class="token operator">=</span> joinPoint<span class="token punctuation">.</span><span class="token function">getSignature</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getName</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>name<span class="token operator">+</span><span class="token string">"方法抛出异常："</span><span class="token operator">+</span>exception<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>LoggerAspect 类定义处添加的两个注解：</p><ul><li><code>@Aspect</code>：表示该类是切面类。</li><li><code>@Component</code>：将该类的对象注入到 IoC 容器。</li></ul><p>具体方法处添加的注解：</p><p><code>@Before</code>：表示方法执行的具体位置和时机。</p><p>CalImpl 也需要添加 <code>@Component</code>，交给 IoC 容器来管理。</p><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>utils<span class="token punctuation">.</span>impl<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>utils<span class="token punctuation">.</span>Cal<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>stereotype<span class="token punctuation">.</span>Component<span class="token punctuation">;</span><span class="token annotation punctuation">@Component</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">CalImpl</span> <span class="token keyword">implements</span> <span class="token class-name">Cal</span> <span class="token punctuation">{</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">add</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span> <span class="token keyword">int</span> num2<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">int</span> result <span class="token operator">=</span> num1<span class="token operator">+</span>num2<span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">sub</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span> <span class="token keyword">int</span> num2<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">int</span> result <span class="token operator">=</span> num1<span class="token operator">-</span>num2<span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">mul</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span> <span class="token keyword">int</span> num2<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">int</span> result <span class="token operator">=</span> num1<span class="token operator">*</span>num2<span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">public</span> <span class="token keyword">int</span> <span class="token function">div</span><span class="token punctuation">(</span><span class="token keyword">int</span> num1<span class="token punctuation">,</span> <span class="token keyword">int</span> num2<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">int</span> result <span class="token operator">=</span> num1<span class="token operator">/</span>num2<span class="token punctuation">;</span> <span class="token keyword">return</span> result<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>spring.xml 中配置 AOP。</p><pre class=" language-xml"><code class="language-xml"><span class="token prolog"><?xml version="1.0" encoding="UTF-8"?></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>beans</span> <span class="token attr-name">xmlns</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/beans<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>xsi</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.w3.org/2001/XMLSchema-instance<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>context</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/context<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>aop</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/aop<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xmlns:</span>p</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/p<span class="token punctuation">"</span></span> <span class="token attr-name"><span class="token namespace">xsi:</span>schemaLocation</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 自动扫描 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">context:</span>component-scan</span> <span class="token attr-name">base-package</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.southwind<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">context:</span>component-scan</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 是Aspect注解生效，为目标类自动生成代理对象 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">aop:</span>aspectj-autoproxy</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">aop:</span>aspectj-autoproxy</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>beans</span><span class="token punctuation">></span></span></code></pre><p><code>context:component-scan</code> 将 <code>com.southwind</code> 包中的所有类进行扫描，如果该类同时添加了 <code>@Component</code>，则将该类扫描到 IoC 容器中，即 IoC 管理它的对象。</p><p><code>aop:aspectj-autoproxy</code> 让 Spring 框架结合切面类和目标类自动生成动态代理对象。</p><ul><li>切面：横切关注点被模块化的抽象对象。</li><li>通知：切面对象完成的工作。</li><li>目标：被通知的对象，即被横切的对象。</li><li>代理：切面、通知、目标混合之后的对象。</li><li>连接点：通知要插入业务代码的具体位置。</li><li>切点：AOP 通过切点定位到连接点。</li></ul>]]></content>
<tags>
<tag> spring </tag>
</tags>
</entry>
<entry>
<title>cookie与session的前生今世</title>
<link href="2021/06/05/cookie-yu-session-de-qian-sheng-jin-shi/"/>
<url>2021/06/05/cookie-yu-session-de-qian-sheng-jin-shi/</url>
<content type="html"><![CDATA[<h2 id="浅谈Session与Cookie的关系"><a href="#浅谈Session与Cookie的关系" class="headerlink" title="浅谈Session与Cookie的关系"></a>浅谈Session与Cookie的关系</h2><p>HTTP是无状态协议，对于事务处理没有记忆能力，每次客服端和服务端完成会话时，服务端不会存储任何会话信息，每个请求都是完全独立的，服务端无法确认当前访问者的身份信息，无法分辨上一次请求发送者和这一次发送者是不是一个人。</p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/cookie%E4%B8%8Esession/merged_1622896410290.jpg" alt="img"></p><p>so，服务器与浏览器为了进行会话跟踪（知道谁在访问我），就必须主动去维护一个状态，这个状态用于告知服务器端前后两个请求是否来自同一个来源，而这个状态需就要通过Cookie或者是Session去实现啦。</p><p>Cookie是一个非常具体的东西，指的是浏览器里面存储的一种数据，仅仅是浏览器实现的一种数据存储的功能，Cookie由服务器生成发送给浏览器，浏览器吧Cookie以key—value形式保存到浏览器中，下一次请求同意服务时，会把cookie发送给服务器，由于Cookie是存储在客户端上的，所以浏览器加入了一些限制，确保Cookie不会被恶意使用，同时不会占太多的磁盘空间，所以每个遇到的Cookie数量是有限的。</p><p>Session从字面上讲就是会话，服务器要知道当前发送请求给自己的是谁，为了做这种区分，服务器就要给每个客户端分配不同的“身份标识”，然后客户端每次向服务器发送请求的时候，都带上这个身份标识，服务器就知道这个请求来自于谁了，至于客户端怎么保存这个身份标识，可有很多种方式，对于浏览器客户端大家都默认使用Cookie的方式，服务器使用session把用户的信息临时保存在服务器上，用户离开网站后Session会被销毁，这种用户信息存储方式相对Cookie来说更加安全，可是session有一个缺陷，如果web服务器做了负载均衡，那么下一个操作请求到了另一台服务器的时候Session就会丢失。</p><p>Cookie和Session的区别：</p><p>1，安全性：session比cookie安全，session是存储在服务器端的，cookie是存储在客户端的</p><p>2，存储值的类型不同：cookie只支持存字符串数据，想要设置其他类型的数据需要将其转换为字符串，而session可以存任意类型的数据类型</p><p>3，有效期不同：Cookie可设置为长时间保持，比如经常使用的默认登录功能，Session一般失效时间短，客户端关闭(默认情况下)或者超市都会失效</p><p>4，存储大小不同：单个Cookie保存的数据不能超过4K，Session可存储数据远高于Cookie，但是当访问量过多，会占用过多服务器资源。</p><p><strong>不管是cookie还是session，都是建立在安全性的大前提下，session中不仅仅有cookie的信息，同时会有该用户的相关重要且安全的信息存储，所以session是在服务器的，而cookie只是服务器将一些不重要的信息拿出来丢给客户的存在，以备以后快速匹配校验用</strong></p>]]></content>
<tags>
<tag> cookie </tag>
<tag> session </tag>
</tags>
</entry>
<entry>
<title>spring mvc详解</title>
<link href="2021/06/05/spring-mvc-xiang-jie/"/>
<url>2021/06/05/spring-mvc-xiang-jie/</url>
<content type="html"><![CDATA[<h3 id="Spring-MVC"><a href="#Spring-MVC" class="headerlink" title="Spring MVC"></a>Spring MVC</h3><p>Spring MVC 是目前主流的实现 MVC 设计模式的企业级开发框架，Spring 框架的一个子模块，无需整合，开发起来更加便捷。</p><h4 id="什么是-MVC-设计模式？"><a href="#什么是-MVC-设计模式？" class="headerlink" title="什么是 MVC 设计模式？"></a>什么是 MVC 设计模式？</h4><p>将应用程序分为 Controller、Model、View 三层，Controller 接收客户端请求，调用 Model 生成业务数据，传递给 View。</p><p>Spring MVC 就是对这套流程的封装，屏蔽了很多底层代码，开放出接口，让开发者可以更加轻松、便捷地完成基于 MVC 模式的 Web 开发。</p><h4 id="Spring-MVC-的核心组件"><a href="#Spring-MVC-的核心组件" class="headerlink" title="Spring MVC 的核心组件"></a>Spring MVC 的核心组件</h4><ul><li>DispatcherServlet：前置控制器，是整个流程控制的核心，控制其他组件的执行，进行统一调度，降低组件之间的耦合性，相当于总指挥。</li><li>Handler：处理器，完成具体的业务逻辑，相当于 Servlet 或 Action。</li><li>HandlerMapping：DispatcherServlet 接收到请求之后，通过 HandlerMapping 将不同的请求映射到不同的 Handler。</li><li>HandlerInterceptor：处理器拦截器，是一个接口，如果需要完成一些拦截处理，可以实现该接口。</li><li>HandlerExecutionChain：处理器执行链，包括两部分内容：Handler 和 HandlerInterceptor（系统会有一个默认的 HandlerInterceptor，如果需要额外设置拦截，可以添加拦截器）。</li><li>HandlerAdapter：处理器适配器，Handler 执行业务方法之前，需要进行一系列的操作，包括表单数据的验证、数据类型的转换、将表单数据封装到 JavaBean 等，这些操作都是由 HandlerApater 来完成，开发者只需将注意力集中业务逻辑的处理上，DispatcherServlet 通过 HandlerAdapter 执行不同的 Handler。</li><li>ModelAndView：装载了模型数据和视图信息，作为 Handler 的处理结果，返回给 DispatcherServlet。</li><li>ViewResolver：视图解析器，DispatcheServlet 通过它将逻辑视图解析为物理视图，最终将渲染结果响应给客户端。</li></ul><h4 id="Spring-MVC-的工作流程"><a href="#Spring-MVC-的工作流程" class="headerlink" title="Spring MVC 的工作流程"></a>Spring MVC 的工作流程</h4><ul><li>客户端请求被 DisptacherServlet 接收。</li><li>根据 HandlerMapping 映射到 Handler。</li><li>生成 Handler 和 HandlerInterceptor。</li><li>Handler 和 HandlerInterceptor 以 HandlerExecutionChain 的形式一并返回给 DisptacherServlet。</li><li>DispatcherServlet 通过 HandlerAdapter 调用 Handler 的方法完成业务逻辑处理。</li><li>Handler 返回一个 ModelAndView 给 DispatcherServlet。</li><li>DispatcherServlet 将获取的 ModelAndView 对象传给 ViewResolver 视图解析器，将逻辑视图解析为物理视图 View。</li><li>ViewResovler 返回一个 View 给 DispatcherServlet。</li><li>DispatcherServlet 根据 View 进行视图渲染（将模型数据 Model 填充到视图 View 中）。</li><li>DispatcherServlet 将渲染后的结果响应给客户端。</li></ul><h3 id="Spring-MVC-注解"><a href="#Spring-MVC-注解" class="headerlink" title="Spring MVC 注解"></a>Spring MVC 注解</h3><ul><li>@RequestMapping </li></ul><p>Spring MVC 通过 @RequestMapping 注解将 URL 请求与业务方法进行映射，在 Handler 的类定义处以及方法定义处都可以添加 @RequestMapping ，在类定义处添加，相当于客户端多了一层访问路径。</p><ul><li>@Controller</li></ul><p>@Controller 在类定义处添加，将该类交个 IoC 容器来管理（结合 springmvc.xml 的自动扫描配置使用），同时使其成为一个控制器，可以接收客户端请求。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Controller</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/hello"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">HelloHandler</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/index"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> String <span class="token function">index</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"执行了index..."</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><ul><li>@RequestMapping 相关参数</li></ul><p>1、value：指定 URL 请求的实际地址，是 @RequestMapping 的默认值。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/index"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">index</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"执行了index..."</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>等于</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span>value<span class="token operator">=</span><span class="token string">"/index"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">index</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"执行了index..."</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>2、method：指定请求的 method 类型，GET、POST、PUT、DELET。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"/index"</span><span class="token punctuation">,</span>method <span class="token operator">=</span> RequestMethod<span class="token punctuation">.</span>GET<span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">index</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"执行了index..."</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>上述代码表示 index 方法只能接收 GET 请求。</p><p>3、params：指定请求中必须包含某些参数，否则无法调用该方法。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"/index"</span><span class="token punctuation">,</span>method <span class="token operator">=</span> RequestMethod<span class="token punctuation">.</span>GET<span class="token punctuation">,</span>params <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">"name"</span><span class="token punctuation">,</span><span class="token string">"id=10"</span><span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">index</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"执行了index..."</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>上述代码表示请求中必须包含 name 和 id 两个参数，同时 id 的值必须是 10。</p><p>关于参数绑定，在形参列表中通过添加 @RequestParam 注解完成 HTTP 请求参数与业务方法形参的映射。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"/index"</span><span class="token punctuation">,</span>method <span class="token operator">=</span> RequestMethod<span class="token punctuation">.</span>GET<span class="token punctuation">,</span>params <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">"name"</span><span class="token punctuation">,</span><span class="token string">"id=10"</span><span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">index</span><span class="token punctuation">(</span><span class="token annotation punctuation">@RequestParam</span><span class="token punctuation">(</span><span class="token string">"name"</span><span class="token punctuation">)</span> String str<span class="token punctuation">,</span><span class="token annotation punctuation">@RequestParam</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">)</span> <span class="token keyword">int</span> age<span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>str<span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>age<span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"执行了index..."</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>上述代码表示将请求的参数 name 和 id 分别赋给了形参 str 和 age ，同时自动完成了数据类型转换，将 “10” 转为了 int 类型的 10，再赋给 age，这些工作都是由 HandlerAdapter 来完成的。</p><p>Spring MVC 也支持 RESTful 风格的 URL。</p><p>传统类型：<a href="http://localhost:8080/hello/index?name=zhangsan&id=10">http://localhost:8080/hello/index?name=zhangsan&id=10</a></p><p>REST：<a href="http://localhost:8080/hello/index/zhangsan/10">http://localhost:8080/hello/index/zhangsan/10</a></p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/rest/{name}/{id}"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">rest</span><span class="token punctuation">(</span><span class="token annotation punctuation">@PathVariable</span><span class="token punctuation">(</span><span class="token string">"name"</span><span class="token punctuation">)</span> String name<span class="token punctuation">,</span><span class="token annotation punctuation">@PathVariable</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">)</span> <span class="token keyword">int</span> id<span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>通过 @PathVariable 注解完成请求参数与形参的映射。</p><ul><li>映射 Cookie</li></ul><p>Spring MVC 通过映射可以直接在业务方法中获取 Cookie 的值。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/cookie"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">cookie</span><span class="token punctuation">(</span><span class="token annotation punctuation">@CookieValue</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"JSESSIONID"</span><span class="token punctuation">)</span> String sessionId<span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>sessionId<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><ul><li>使用 JavaBean 绑定参数</li></ul><p>Spring MVC 会根据请求参数名和 JavaBean 属性名进行自动匹配，自动为对象填充属性值，同时支持及联属性。</p><p>如果出现中文乱码问题，只需在 web.xml 添加 Spring MVC 自带的过滤器即可。</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter-name</span><span class="token punctuation">></span></span>encodingFilter<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter-class</span><span class="token punctuation">></span></span>org.springframework.web.filter.CharacterEncodingFilter<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter-class</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>init-param</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>param-name</span><span class="token punctuation">></span></span>encoding<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>param-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>param-value</span><span class="token punctuation">></span></span>UTF-8<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>param-value</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>init-param</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>filter-name</span><span class="token punctuation">></span></span>encodingFilter<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>url-pattern</span><span class="token punctuation">></span></span>/*<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>url-pattern</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>filter-mapping</span><span class="token punctuation">></span></span></code></pre><ul><li>JSP 页面的转发和重定向：</li></ul><p>Spring MVC 默认是以转发的形式响应 JSP。</p><p>1、转发</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/forward"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">forward</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> <span class="token string">"forward:/index.jsp"</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">// return "index";</span><span class="token punctuation">}</span></code></pre><p>2、重定向</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/redirect"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">redirect</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> <span class="token string">"redirect:/index.jsp"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><h3 id="Spring-MVC-数据绑定"><a href="#Spring-MVC-数据绑定" class="headerlink" title="Spring MVC 数据绑定"></a>Spring MVC 数据绑定</h3><p>数据绑定：在后端的业务方法中直接获取客户端 HTTP 请求中的参数，将请求参数映射到业务方法的形参中，Spring MVC 中数据绑定的工作是由 HandlerAdapter 来完成的。</p><ul><li>基本数据类型</li></ul><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/baseType"</span><span class="token punctuation">)</span><span class="token annotation punctuation">@ResponseBody</span><span class="token keyword">public</span> String <span class="token function">baseType</span><span class="token punctuation">(</span><span class="token keyword">int</span> id<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> id<span class="token operator">+</span><span class="token string">""</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>@ResponseBody 表示 Spring MVC 会直接将业务方法的返回值响应给客户端，如果不加 @ResponseBody 注解，Spring MVC 会将业务方法的放回值传递给 DispatcherServlet，再由 DisptacherServlet 调用 ViewResolver 对返回值进行解析，映射到一个 JSP 资源。</p><ul><li>包装类</li></ul><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/packageType"</span><span class="token punctuation">)</span><span class="token annotation punctuation">@ResponseBody</span><span class="token keyword">public</span> String <span class="token function">packageType</span><span class="token punctuation">(</span><span class="token annotation punctuation">@RequestParam</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token string">"num"</span><span class="token punctuation">,</span>required <span class="token operator">=</span> <span class="token boolean">false</span><span class="token punctuation">,</span>defaultValue <span class="token operator">=</span> <span class="token string">"0"</span><span class="token punctuation">)</span> Integer id<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> id<span class="token operator">+</span><span class="token string">""</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>包装类可以接收 null，当 HTTP 请求没有参数时，使用包装类定义形参的数据类型，程序不会抛出异常。</p><p>@RequestParam</p><p>value = “num”：将 HTTP 请求中名为 num 的参数赋给形参 id。</p><p>requried：设置 num 是否为必填项，true 表示必填，false 表示非必填，可省略。</p><p>defaultValue = “0”：如果 HTTP 请求中没有 num 参数，默认值为0.</p><ul><li>数组</li></ul><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RestController</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/data"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">DataBindHandler</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/array"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> String <span class="token function">array</span><span class="token punctuation">(</span>String<span class="token punctuation">[</span><span class="token punctuation">]</span> name<span class="token punctuation">)</span><span class="token punctuation">{</span> String str <span class="token operator">=</span> Arrays<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> str<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>@RestController 表示该控制器会直接将业务方法的返回值响应给客户端，不进行视图解析。</p><p>@Controller 表示该控制器的每一个业务方法的返回值都会交给视图解析器进行解析，如果只需要将数据响应给客户端，而不需要进行视图解析，则需要在对应的业务方法定义处添加 @ResponseBody。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RestController</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/data"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">DataBindHandler</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/array"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> String <span class="token function">array</span><span class="token punctuation">(</span>String<span class="token punctuation">[</span><span class="token punctuation">]</span> name<span class="token punctuation">)</span><span class="token punctuation">{</span> String str <span class="token operator">=</span> Arrays<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> str<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>等同于</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Controller</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/data"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">DataBindHandler</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/array"</span><span class="token punctuation">)</span> <span class="token annotation punctuation">@ResponseBody</span> <span class="token keyword">public</span> String <span class="token function">array</span><span class="token punctuation">(</span>String<span class="token punctuation">[</span><span class="token punctuation">]</span> name<span class="token punctuation">)</span><span class="token punctuation">{</span> String str <span class="token operator">=</span> Arrays<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> str<span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><ul><li>List</li></ul><p>Spring MVC 不支持 List 类型的直接转换，需要对 List 集合进行包装。</p><p>集合封装类</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Data</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">UserList</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> List<span class="token operator"><</span>User<span class="token operator">></span> users<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>JSP</p><pre class=" language-java"><code class="language-java"><span class="token operator"><</span><span class="token operator">%</span>@ page contentType<span class="token operator">=</span><span class="token string">"text/html;charset=UTF-8"</span> language<span class="token operator">=</span><span class="token string">"java"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span>html<span class="token operator">></span><span class="token operator"><</span>head<span class="token operator">></span> <span class="token operator"><</span>title<span class="token operator">></span>Title<span class="token operator"><</span><span class="token operator">/</span>title<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>head<span class="token operator">></span><span class="token operator"><</span>body<span class="token operator">></span> <span class="token operator"><</span>form action<span class="token operator">=</span><span class="token string">"/data/list"</span> method<span class="token operator">=</span><span class="token string">"post"</span><span class="token operator">></span> 用户<span class="token number">1</span>编号：<span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"text"</span> name<span class="token operator">=</span><span class="token string">"users[0].id"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 用户<span class="token number">1</span>名称：<span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"text"</span> name<span class="token operator">=</span><span class="token string">"users[0].name"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 用户<span class="token number">2</span>编号：<span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"text"</span> name<span class="token operator">=</span><span class="token string">"users[1].id"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 用户<span class="token number">2</span>名称：<span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"text"</span> name<span class="token operator">=</span><span class="token string">"users[1].name"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 用户<span class="token number">3</span>编号：<span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"text"</span> name<span class="token operator">=</span><span class="token string">"users[2].id"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 用户<span class="token number">3</span>名称：<span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"text"</span> name<span class="token operator">=</span><span class="token string">"users[2].name"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"submit"</span> value<span class="token operator">=</span><span class="token string">"提交"</span><span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>html<span class="token operator">></span></code></pre><p>业务方法</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/list"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">list</span><span class="token punctuation">(</span>UserList userList<span class="token punctuation">)</span><span class="token punctuation">{</span> StringBuffer str <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">StringBuffer</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">for</span><span class="token punctuation">(</span>User user<span class="token operator">:</span>userList<span class="token punctuation">.</span><span class="token function">getUsers</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> str<span class="token punctuation">.</span><span class="token function">append</span><span class="token punctuation">(</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">return</span> str<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>处理 @ResponseBody 中文乱码，在 springmvc.xml 中配置消息转换器。</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">mvc:</span>annotation-driven</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 消息转换器 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">mvc:</span>message-converters</span> <span class="token attr-name">register-defaults</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>true<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>org.springframework.http.converter.StringHttpMessageConverter<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>supportedMediaTypes<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/html;charset<span class="token punctuation">=</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">mvc:</span>message-converters</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">mvc:</span>annotation-driven</span><span class="token punctuation">></span></span></code></pre><ul><li>JSON</li></ul><p>客户端发生 JSON 格式的数据，直接通过 Spring MVC 绑定到业务方法的形参中。</p><p>处理 Spring MVC 无法加载静态资源，在 web.xml 中添加配置即可。</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-name</span><span class="token punctuation">></span></span>default<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>url-pattern</span><span class="token punctuation">></span></span>*.js<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>url-pattern</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-mapping</span><span class="token punctuation">></span></span></code></pre><p>JSP</p><pre class=" language-java"><code class="language-java"><span class="token operator"><</span><span class="token operator">%</span>@ page contentType<span class="token operator">=</span><span class="token string">"text/html;charset=UTF-8"</span> language<span class="token operator">=</span><span class="token string">"java"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span>html<span class="token operator">></span><span class="token operator"><</span>head<span class="token operator">></span> <span class="token operator"><</span>title<span class="token operator">></span>Title<span class="token operator"><</span><span class="token operator">/</span>title<span class="token operator">></span> <span class="token operator"><</span>script type<span class="token operator">=</span><span class="token string">"text/javascript"</span> src<span class="token operator">=</span><span class="token string">"js/jquery-3.3.1.min.js"</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>script<span class="token operator">></span> <span class="token operator"><</span>script type<span class="token operator">=</span><span class="token string">"text/javascript"</span><span class="token operator">></span> $<span class="token punctuation">(</span><span class="token function">function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> var user <span class="token operator">=</span> <span class="token punctuation">{</span> <span class="token string">"id"</span><span class="token operator">:</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token string">"name"</span><span class="token operator">:</span><span class="token string">"张三"</span> <span class="token punctuation">}</span><span class="token punctuation">;</span> $<span class="token punctuation">.</span><span class="token function">ajax</span><span class="token punctuation">(</span><span class="token punctuation">{</span> url<span class="token operator">:</span><span class="token string">"/data/json"</span><span class="token punctuation">,</span> data<span class="token operator">:</span>JSON<span class="token punctuation">.</span><span class="token function">stringify</span><span class="token punctuation">(</span>user<span class="token punctuation">)</span><span class="token punctuation">,</span> type<span class="token operator">:</span><span class="token string">"POST"</span><span class="token punctuation">,</span> contentType<span class="token operator">:</span><span class="token string">"application/json;charset=UTF-8"</span><span class="token punctuation">,</span> dataType<span class="token operator">:</span><span class="token string">"JSON"</span><span class="token punctuation">,</span> success<span class="token operator">:</span><span class="token function">function</span><span class="token punctuation">(</span>data<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">alter</span><span class="token punctuation">(</span>data<span class="token punctuation">.</span>id<span class="token operator">+</span><span class="token string">"---"</span><span class="token operator">+</span>data<span class="token punctuation">.</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token operator"><</span><span class="token operator">/</span>script<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>head<span class="token operator">></span><span class="token operator"><</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>html<span class="token operator">></span></code></pre><p>业务方法</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/json"</span><span class="token punctuation">)</span><span class="token keyword">public</span> User <span class="token function">json</span><span class="token punctuation">(</span><span class="token annotation punctuation">@RequestBody</span> User user<span class="token punctuation">)</span><span class="token punctuation">{</span> System<span class="token punctuation">.</span>out<span class="token punctuation">.</span><span class="token function">println</span><span class="token punctuation">(</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span><span class="token number">6</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张六"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> user<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>Spring MVC 中的 JSON 和 JavaBean 的转换需要借助于 fastjson，pom.xml 引入相关依赖。</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>com.alibaba<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>fastjson<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>1.2.32<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span></code></pre><p>springmvc.xml 添加 fastjson 配置。</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">mvc:</span>annotation-driven</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 消息转换器 --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">mvc:</span>message-converters</span> <span class="token attr-name">register-defaults</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>true<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>org.springframework.http.converter.StringHttpMessageConverter<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>property</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>supportedMediaTypes<span class="token punctuation">"</span></span> <span class="token attr-name">value</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>text/html;charset<span class="token punctuation">=</span>UTF-8<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>property</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span> <span class="token comment" spellcheck="true"><!-- 配置fastjson --></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter4<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">mvc:</span>message-converters</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">mvc:</span>annotation-driven</span><span class="token punctuation">></span></span></code></pre><h3 id="Spring-MVC-模型数据解析"><a href="#Spring-MVC-模型数据解析" class="headerlink" title="Spring MVC 模型数据解析"></a>Spring MVC 模型数据解析</h3><p>JSP 四大作用域对应的内置对象：pageContext、request、session、application。</p><p>模型数据的绑定是由 ViewResolver 来完成的，实际开发中，我们需要先添加模型数据，再交给 ViewResolver 来绑定。</p><p>Spring MVC 提供了以下几种方式添加模型数据：</p><ul><li>Map</li><li>Model</li><li>ModelAndView</li><li>@SessionAttribute</li><li>@ModelAttribute</li></ul><blockquote><p>将模式数据绑定到 request 对象。</p></blockquote><p>1、Map</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/map"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">map</span><span class="token punctuation">(</span>Map<span class="token operator"><</span>String<span class="token punctuation">,</span>User<span class="token operator">></span> map<span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> map<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"view"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>JSP</p><pre class=" language-java"><code class="language-java"><span class="token operator"><</span><span class="token operator">%</span>@ page contentType<span class="token operator">=</span><span class="token string">"text/html;charset=UTF-8"</span> language<span class="token operator">=</span><span class="token string">"java"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ page isELIgnored<span class="token operator">=</span><span class="token string">"false"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span>html<span class="token operator">></span><span class="token operator"><</span>head<span class="token operator">></span> <span class="token operator"><</span>title<span class="token operator">></span>Title<span class="token operator"><</span><span class="token operator">/</span>title<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>head<span class="token operator">></span><span class="token operator"><</span>body<span class="token operator">></span> $<span class="token punctuation">{</span>requestScope<span class="token punctuation">.</span>user<span class="token punctuation">}</span><span class="token operator"><</span><span class="token operator">/</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>html<span class="token operator">></span></code></pre><p>2、Model</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/model"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">model</span><span class="token punctuation">(</span>Model model<span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> model<span class="token punctuation">.</span><span class="token function">addAttribute</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"view"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>3、ModelAndView</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAndView"</span><span class="token punctuation">)</span><span class="token keyword">public</span> ModelAndView <span class="token function">modelAndView</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> modelAndView<span class="token punctuation">.</span><span class="token function">addObject</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> modelAndView<span class="token punctuation">.</span><span class="token function">setViewName</span><span class="token punctuation">(</span><span class="token string">"view"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAndView2"</span><span class="token punctuation">)</span><span class="token keyword">public</span> ModelAndView <span class="token function">modelAndView2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> modelAndView<span class="token punctuation">.</span><span class="token function">addObject</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> View view <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">InternalResourceView</span><span class="token punctuation">(</span><span class="token string">"/view.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> modelAndView<span class="token punctuation">.</span><span class="token function">setView</span><span class="token punctuation">(</span>view<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAndView3"</span><span class="token punctuation">)</span><span class="token keyword">public</span> ModelAndView <span class="token function">modelAndView3</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span><span class="token string">"view"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> modelAndView<span class="token punctuation">.</span><span class="token function">addObject</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAndView4"</span><span class="token punctuation">)</span><span class="token keyword">public</span> ModelAndView <span class="token function">modelAndView4</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> View view <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">InternalResourceView</span><span class="token punctuation">(</span><span class="token string">"/view.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span>view<span class="token punctuation">)</span><span class="token punctuation">;</span> modelAndView<span class="token punctuation">.</span><span class="token function">addObject</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAndView5"</span><span class="token punctuation">)</span><span class="token keyword">public</span> ModelAndView <span class="token function">modelAndView5</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> Map<span class="token operator"><</span>String<span class="token punctuation">,</span>User<span class="token operator">></span> map <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token operator"><</span><span class="token operator">></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> map<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span><span class="token string">"view"</span><span class="token punctuation">,</span>map<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAndView6"</span><span class="token punctuation">)</span><span class="token keyword">public</span> ModelAndView <span class="token function">modelAndView6</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> Map<span class="token operator"><</span>String<span class="token punctuation">,</span>User<span class="token operator">></span> map <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token operator"><</span><span class="token operator">></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> map<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> View view <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">InternalResourceView</span><span class="token punctuation">(</span><span class="token string">"/view.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span>view<span class="token punctuation">,</span>map<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAndView7"</span><span class="token punctuation">)</span><span class="token keyword">public</span> ModelAndView <span class="token function">modelAndView7</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span><span class="token string">"view"</span><span class="token punctuation">,</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAndView8"</span><span class="token punctuation">)</span><span class="token keyword">public</span> ModelAndView <span class="token function">modelAndView8</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> View view <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">InternalResourceView</span><span class="token punctuation">(</span><span class="token string">"/view.jsp"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> ModelAndView modelAndView <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ModelAndView</span><span class="token punctuation">(</span>view<span class="token punctuation">,</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> modelAndView<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>4、HttpServletRequest</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/request"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">request</span><span class="token punctuation">(</span>HttpServletRequest request<span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> request<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"view"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>5、@ModelAttribute</p><ul><li>定义一个方法，该方法专门用来返回要填充到模型数据中的对象。</li></ul><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@ModelAttribute</span><span class="token keyword">public</span> User <span class="token function">getUser</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> user<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@ModelAttribute</span><span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">getUser</span><span class="token punctuation">(</span>Map<span class="token operator"><</span>String<span class="token punctuation">,</span>User<span class="token operator">></span> map<span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> map<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@ModelAttribute</span><span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">getUser</span><span class="token punctuation">(</span>Model model<span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> model<span class="token punctuation">.</span><span class="token function">addAttribute</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><ul><li>业务方法中无需再处理模型数据，只需返回视图即可。</li></ul><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/modelAttribute"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">modelAttribute</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> <span class="token string">"view"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><blockquote><p>将模型数据绑定到 session 对象</p></blockquote><p>1、直接使用原生的 Servlet API。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/session"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">session</span><span class="token punctuation">(</span>HttpServletRequest request<span class="token punctuation">)</span><span class="token punctuation">{</span> HttpSession session <span class="token operator">=</span> request<span class="token punctuation">.</span><span class="token function">getSession</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> session<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"view"</span><span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/session2"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">session2</span><span class="token punctuation">(</span>HttpSession session<span class="token punctuation">)</span><span class="token punctuation">{</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> session<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"view"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>2、@SessionAttribute</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@SessionAttributes</span><span class="token punctuation">(</span>value <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token string">"user"</span><span class="token punctuation">,</span><span class="token string">"address"</span><span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">ViewHandler</span> <span class="token punctuation">{</span><span class="token punctuation">}</span></code></pre><p>对于 ViewHandler 中的所有业务方法，只要向 request 中添加了 key = “user”、key = “address” 的对象时，Spring MVC 会自动将该数据添加到 session 中，保存 key 不变。</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@SessionAttributes</span><span class="token punctuation">(</span>types <span class="token operator">=</span> <span class="token punctuation">{</span>User<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">,</span>Address<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">ViewHandler</span> <span class="token punctuation">{</span><span class="token punctuation">}</span></code></pre><p>对于 ViewHandler 中的所有业务方法，只要向 request 中添加了数据类型是 User 、Address 的对象时，Spring MVC 会自动将该数据添加到 session 中，保存 key 不变。</p><blockquote><p>将模型数据绑定到 application 对象</p></blockquote><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/application"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">application</span><span class="token punctuation">(</span>HttpServletRequest request<span class="token punctuation">)</span><span class="token punctuation">{</span> ServletContext application <span class="token operator">=</span> request<span class="token punctuation">.</span><span class="token function">getServletContext</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> User user <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">User</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setId</span><span class="token punctuation">(</span>1L<span class="token punctuation">)</span><span class="token punctuation">;</span> user<span class="token punctuation">.</span><span class="token function">setName</span><span class="token punctuation">(</span><span class="token string">"张三"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> application<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"user"</span><span class="token punctuation">,</span>user<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"view"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><h3 id="Spring-MVC-REST"><a href="#Spring-MVC-REST" class="headerlink" title="Spring MVC REST"></a>Spring MVC REST</h3><p>REST：Representational State Transfer，资源表现层状态转换，是目前比较主流的一种互联网软件架构，它结构清晰、标准规范、易于理解、便于扩展。</p><ul><li>资源（Resource）</li></ul><p>网络上的一个实体，或者说网络中存在的一个具体信息，一段文本、一张图片、一首歌曲、一段视频等等，总之就是一个具体的存在。可以用一个 URI（统一资源定位符）指向它，每个资源都有对应的一个特定的 URI，要获取该资源时，只需要访问对应的 URI 即可。</p><ul><li>表现层（Representation）</li></ul><p>资源具体呈现出来的形式，比如文本可以用 txt 格式表示，也可以用 HTML、XML、JSON等格式来表示。</p><ul><li>状态转换（State Transfer）</li></ul><p>客户端如果希望操作服务器中的某个资源，就需要通过某种方式让服务端发生状态转换，而这种转换是建立在表现层之上的，所有叫做”表现层状态转换”。</p><h4 id="特点"><a href="#特点" class="headerlink" title="特点"></a>特点</h4><ul><li>URL 更加简洁。</li><li>有利于不同系统之间的资源共享，只需要遵守一定的规范，不需要进行其他配置即可实现资源共享。</li></ul><h4 id="如何使用"><a href="#如何使用" class="headerlink" title="如何使用"></a>如何使用</h4><p>REST 具体操作就是 HTTP 协议中四个表示操作方式的动词分别对应 CRUD 基本操作。</p><p>GET 用来表示获取资源。</p><p>POST 用来表示新建资源。</p><p>PUT 用来表示修改资源。</p><p>DELETE 用来表示删除资源。</p><p>Handler</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@RestController</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/rest"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">RESTHandeler</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Autowired</span> <span class="token keyword">private</span> StudentRepository studentRepository<span class="token punctuation">;</span> <span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/findAll"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> Collection<span class="token operator"><</span>Student<span class="token operator">></span> <span class="token function">findAll</span><span class="token punctuation">(</span>HttpServletResponse response<span class="token punctuation">)</span><span class="token punctuation">{</span> response<span class="token punctuation">.</span><span class="token function">setContentType</span><span class="token punctuation">(</span><span class="token string">"text/json;charset=UTF-8"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> studentRepository<span class="token punctuation">.</span><span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/findById/{id}"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> Student <span class="token function">findById</span><span class="token punctuation">(</span><span class="token annotation punctuation">@PathVariable</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">)</span> <span class="token keyword">long</span> id<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> studentRepository<span class="token punctuation">.</span><span class="token function">findById</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@PostMapping</span><span class="token punctuation">(</span><span class="token string">"/save"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">save</span><span class="token punctuation">(</span><span class="token annotation punctuation">@RequestBody</span> Student student<span class="token punctuation">)</span><span class="token punctuation">{</span> studentRepository<span class="token punctuation">.</span><span class="token function">saveOrUpdate</span><span class="token punctuation">(</span>student<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@PutMapping</span><span class="token punctuation">(</span><span class="token string">"/update"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">update</span><span class="token punctuation">(</span><span class="token annotation punctuation">@RequestBody</span> Student student<span class="token punctuation">)</span><span class="token punctuation">{</span> studentRepository<span class="token punctuation">.</span><span class="token function">saveOrUpdate</span><span class="token punctuation">(</span>student<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@DeleteMapping</span><span class="token punctuation">(</span><span class="token string">"/deleteById/{id}"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">deleteById</span><span class="token punctuation">(</span><span class="token annotation punctuation">@PathVariable</span><span class="token punctuation">(</span><span class="token string">"id"</span><span class="token punctuation">)</span> <span class="token keyword">long</span> id<span class="token punctuation">)</span><span class="token punctuation">{</span> studentRepository<span class="token punctuation">.</span><span class="token function">deleteById</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><p>StudentRepository</p><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>aynu<span class="token punctuation">.</span>repository<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>entity<span class="token punctuation">.</span>Student<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Collection<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">interface</span> <span class="token class-name">StudentRepository</span> <span class="token punctuation">{</span> <span class="token keyword">public</span> Collection<span class="token operator"><</span>Student<span class="token operator">></span> <span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">public</span> Student <span class="token function">findById</span><span class="token punctuation">(</span><span class="token keyword">long</span> id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">saveOrUpdate</span><span class="token punctuation">(</span>Student student<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">deleteById</span><span class="token punctuation">(</span><span class="token keyword">long</span> id<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><p>StudentRepositoryImpl</p><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>aynu<span class="token punctuation">.</span>repository<span class="token punctuation">.</span>impl<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>entity<span class="token punctuation">.</span>Student<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>southwind<span class="token punctuation">.</span>repository<span class="token punctuation">.</span>StudentRepository<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>stereotype<span class="token punctuation">.</span>Repository<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Collection<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>HashMap<span class="token punctuation">;</span><span class="token keyword">import</span> java<span class="token punctuation">.</span>util<span class="token punctuation">.</span>Map<span class="token punctuation">;</span><span class="token annotation punctuation">@Repository</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">StudentRepositoryImpl</span> <span class="token keyword">implements</span> <span class="token class-name">StudentRepository</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> <span class="token keyword">static</span> Map<span class="token operator"><</span>Long<span class="token punctuation">,</span>Student<span class="token operator">></span> studentMap<span class="token punctuation">;</span> <span class="token keyword">static</span><span class="token punctuation">{</span> studentMap <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">HashMap</span><span class="token operator"><</span><span class="token operator">></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> studentMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>1L<span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Student</span><span class="token punctuation">(</span>1L<span class="token punctuation">,</span><span class="token string">"张三"</span><span class="token punctuation">,</span><span class="token number">22</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> studentMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>2L<span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Student</span><span class="token punctuation">(</span>2L<span class="token punctuation">,</span><span class="token string">"李四"</span><span class="token punctuation">,</span><span class="token number">23</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> studentMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>3L<span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Student</span><span class="token punctuation">(</span>3L<span class="token punctuation">,</span><span class="token string">"王五"</span><span class="token punctuation">,</span><span class="token number">24</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> Collection<span class="token operator"><</span>Student<span class="token operator">></span> <span class="token function">findAll</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">return</span> studentMap<span class="token punctuation">.</span><span class="token function">values</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> Student <span class="token function">findById</span><span class="token punctuation">(</span><span class="token keyword">long</span> id<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">return</span> studentMap<span class="token punctuation">.</span><span class="token function">get</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">saveOrUpdate</span><span class="token punctuation">(</span>Student student<span class="token punctuation">)</span> <span class="token punctuation">{</span> studentMap<span class="token punctuation">.</span><span class="token function">put</span><span class="token punctuation">(</span>student<span class="token punctuation">.</span><span class="token function">getId</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span>student<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">deleteById</span><span class="token punctuation">(</span><span class="token keyword">long</span> id<span class="token punctuation">)</span> <span class="token punctuation">{</span> studentMap<span class="token punctuation">.</span><span class="token function">remove</span><span class="token punctuation">(</span>id<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><h3 id="Spring-MVC-文件上传下载"><a href="#Spring-MVC-文件上传下载" class="headerlink" title="Spring MVC 文件上传下载"></a>Spring MVC 文件上传下载</h3><blockquote><p>单文件上传</p></blockquote><p>底层是使用 Apache fileupload 组件完成上传，Spring MVC 对这种方式进行了封装。</p><ul><li>pom.xml</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>commons-io<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>commons-io<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>2.5<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>commons-fileupload<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>commons-fileupload<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>1.3.3<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span></code></pre><ul><li>JSP</li></ul><pre class=" language-java"><code class="language-java"><span class="token operator"><</span><span class="token operator">%</span>@ page contentType<span class="token operator">=</span><span class="token string">"text/html;charset=UTF-8"</span> language<span class="token operator">=</span><span class="token string">"java"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ page isELIgnored<span class="token operator">=</span><span class="token string">"false"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span>html<span class="token operator">></span><span class="token operator"><</span>head<span class="token operator">></span> <span class="token operator"><</span>title<span class="token operator">></span>Title<span class="token operator"><</span><span class="token operator">/</span>title<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>head<span class="token operator">></span><span class="token operator"><</span>body<span class="token operator">></span> <span class="token operator"><</span>form action<span class="token operator">=</span><span class="token string">"/file/upload"</span> method<span class="token operator">=</span><span class="token string">"post"</span> enctype<span class="token operator">=</span><span class="token string">"multipart/form-data"</span><span class="token operator">></span> <span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"file"</span> name<span class="token operator">=</span><span class="token string">"img"</span><span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"submit"</span> value<span class="token operator">=</span><span class="token string">"上传"</span><span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">></span> <span class="token operator"><</span>img src<span class="token operator">=</span><span class="token string">"${path}"</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>html<span class="token operator">></span></code></pre><p>1、input 的 type 设置为 file。</p><p>2、form 的 method 设置为 post（get 请求只能将文件名传给服务器）</p><p>3、from 的 enctype 设置为 multipart-form-data（如果不设置只能将文件名传给服务器）</p><ul><li>Handler</li></ul><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@Controller</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/file"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">FileHandler</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@PostMapping</span><span class="token punctuation">(</span><span class="token string">"/upload"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> String <span class="token function">upload</span><span class="token punctuation">(</span>MultipartFile img<span class="token punctuation">,</span> HttpServletRequest request<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span><span class="token punctuation">(</span>img<span class="token punctuation">.</span><span class="token function">getSize</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">></span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//获取保存上传文件的file路径</span> String path <span class="token operator">=</span> request<span class="token punctuation">.</span><span class="token function">getServletContext</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getRealPath</span><span class="token punctuation">(</span><span class="token string">"file"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//获取上传的文件名</span> String name <span class="token operator">=</span> img<span class="token punctuation">.</span><span class="token function">getOriginalFilename</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> File file <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">File</span><span class="token punctuation">(</span>path<span class="token punctuation">,</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">try</span> <span class="token punctuation">{</span> img<span class="token punctuation">.</span><span class="token function">transferTo</span><span class="token punctuation">(</span>file<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//保存上传之后的文件路径</span> request<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"path"</span><span class="token punctuation">,</span><span class="token string">"/file/"</span><span class="token operator">+</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token keyword">return</span> <span class="token string">"upload"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><ul><li>springmvc.xml</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token comment" spellcheck="true"><!-- 配置上传组件 --></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>multipartResolver<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>org.springframework.web.multipart.commons.CommonsMultipartResolver<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span></code></pre><ul><li>web.xml 添加如下配置，否则客户端无法访问 png</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-mapping</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>servlet-name</span><span class="token punctuation">></span></span>default<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-name</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>url-pattern</span><span class="token punctuation">></span></span>*.png<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>url-pattern</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>servlet-mapping</span><span class="token punctuation">></span></span></code></pre><blockquote><p>多文件上传</p></blockquote><p>pom.xml</p><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>jstl<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>jstl<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>1.2<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>taglibs<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>standard<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>1.1.2<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span></code></pre><p>JSP</p><pre class=" language-java"><code class="language-java"><span class="token operator"><</span><span class="token operator">%</span>@ page contentType<span class="token operator">=</span><span class="token string">"text/html;charset=UTF-8"</span> language<span class="token operator">=</span><span class="token string">"java"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ page isELIgnored<span class="token operator">=</span><span class="token string">"false"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ taglib prefix<span class="token operator">=</span><span class="token string">"c"</span> uri<span class="token operator">=</span><span class="token string">"http://java.sun.com/jsp/jstl/core"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span>html<span class="token operator">></span><span class="token operator"><</span>head<span class="token operator">></span> <span class="token operator"><</span>title<span class="token operator">></span>Title<span class="token operator"><</span><span class="token operator">/</span>title<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>head<span class="token operator">></span><span class="token operator"><</span>body<span class="token operator">></span> <span class="token operator"><</span>form action<span class="token operator">=</span><span class="token string">"/file/uploads"</span> method<span class="token operator">=</span><span class="token string">"post"</span> enctype<span class="token operator">=</span><span class="token string">"multipart/form-data"</span><span class="token operator">></span> file1<span class="token operator">:</span><span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"file"</span> name<span class="token operator">=</span><span class="token string">"imgs"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> file2<span class="token operator">:</span><span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"file"</span> name<span class="token operator">=</span><span class="token string">"imgs"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> file3<span class="token operator">:</span><span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"file"</span> name<span class="token operator">=</span><span class="token string">"imgs"</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"submit"</span> value<span class="token operator">=</span><span class="token string">"上传"</span><span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">></span> <span class="token operator"><</span>c<span class="token operator">:</span>forEach items<span class="token operator">=</span><span class="token string">"${files}"</span> var<span class="token operator">=</span><span class="token string">"file"</span> <span class="token operator">></span> <span class="token operator"><</span>img src<span class="token operator">=</span><span class="token string">"${file}"</span> width<span class="token operator">=</span><span class="token string">"300px"</span><span class="token operator">></span> <span class="token operator"><</span><span class="token operator">/</span>c<span class="token operator">:</span>forEach<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>html<span class="token operator">></span></code></pre><p>Handler</p><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@PostMapping</span><span class="token punctuation">(</span><span class="token string">"/uploads"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">uploads</span><span class="token punctuation">(</span>MultipartFile<span class="token punctuation">[</span><span class="token punctuation">]</span> imgs<span class="token punctuation">,</span>HttpServletRequest request<span class="token punctuation">)</span><span class="token punctuation">{</span> List<span class="token operator"><</span>String<span class="token operator">></span> files <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">ArrayList</span><span class="token operator"><</span><span class="token operator">></span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">for</span> <span class="token punctuation">(</span>MultipartFile img<span class="token operator">:</span>imgs<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span><span class="token punctuation">(</span>img<span class="token punctuation">.</span><span class="token function">getSize</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">></span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token comment" spellcheck="true">//获取保存上传文件的file路径</span> String path <span class="token operator">=</span> request<span class="token punctuation">.</span><span class="token function">getServletContext</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getRealPath</span><span class="token punctuation">(</span><span class="token string">"file"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//获取上传的文件名</span> String name <span class="token operator">=</span> img<span class="token punctuation">.</span><span class="token function">getOriginalFilename</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> File file <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">File</span><span class="token punctuation">(</span>path<span class="token punctuation">,</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">try</span> <span class="token punctuation">{</span> img<span class="token punctuation">.</span><span class="token function">transferTo</span><span class="token punctuation">(</span>file<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment" spellcheck="true">//保存上传之后的文件路径</span> files<span class="token punctuation">.</span><span class="token function">add</span><span class="token punctuation">(</span><span class="token string">"/file/"</span><span class="token operator">+</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> request<span class="token punctuation">.</span><span class="token function">setAttribute</span><span class="token punctuation">(</span><span class="token string">"files"</span><span class="token punctuation">,</span>files<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"uploads"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><blockquote><p>下载</p></blockquote><ul><li>JSP</li></ul><pre class=" language-java"><code class="language-java"><span class="token operator"><</span><span class="token operator">%</span><span class="token operator">--</span> Created by IntelliJ IDEA<span class="token punctuation">.</span> User<span class="token operator">:</span> southwind Date<span class="token operator">:</span> <span class="token number">2019</span><span class="token operator">-</span><span class="token number">03</span><span class="token operator">-</span><span class="token number">15</span> Time<span class="token operator">:</span> <span class="token number">10</span><span class="token operator">:</span><span class="token number">36</span> To change <span class="token keyword">this</span> template use File <span class="token operator">|</span> Settings <span class="token operator">|</span> File Templates<span class="token punctuation">.</span><span class="token operator">--</span><span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ page contentType<span class="token operator">=</span><span class="token string">"text/html;charset=UTF-8"</span> language<span class="token operator">=</span><span class="token string">"java"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span>html<span class="token operator">></span><span class="token operator"><</span>head<span class="token operator">></span> <span class="token operator"><</span>title<span class="token operator">></span>Title<span class="token operator"><</span><span class="token operator">/</span>title<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>head<span class="token operator">></span><span class="token operator"><</span>body<span class="token operator">></span> <span class="token operator"><</span>a href<span class="token operator">=</span><span class="token string">"/file/download/1"</span><span class="token operator">></span><span class="token number">1</span><span class="token punctuation">.</span>png<span class="token operator"><</span><span class="token operator">/</span>a<span class="token operator">></span> <span class="token operator"><</span>a href<span class="token operator">=</span><span class="token string">"/file/download/2"</span><span class="token operator">></span><span class="token number">2</span><span class="token punctuation">.</span>png<span class="token operator"><</span><span class="token operator">/</span>a<span class="token operator">></span> <span class="token operator"><</span>a href<span class="token operator">=</span><span class="token string">"/file/download/3"</span><span class="token operator">></span><span class="token number">3</span><span class="token punctuation">.</span>png<span class="token operator"><</span><span class="token operator">/</span>a<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>html<span class="token operator">></span></code></pre><ul><li>Handler</li></ul><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/download/{name}"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">download</span><span class="token punctuation">(</span><span class="token annotation punctuation">@PathVariable</span><span class="token punctuation">(</span><span class="token string">"name"</span><span class="token punctuation">)</span> String name<span class="token punctuation">,</span> HttpServletRequest request<span class="token punctuation">,</span> HttpServletResponse response<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span><span class="token punctuation">(</span>name <span class="token operator">!=</span> null<span class="token punctuation">)</span><span class="token punctuation">{</span> name <span class="token operator">+=</span> <span class="token string">".png"</span><span class="token punctuation">;</span> String path <span class="token operator">=</span> request<span class="token punctuation">.</span><span class="token function">getServletContext</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">getRealPath</span><span class="token punctuation">(</span><span class="token string">"file"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> File file <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">File</span><span class="token punctuation">(</span>path<span class="token punctuation">,</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> OutputStream outputStream <span class="token operator">=</span> null<span class="token punctuation">;</span> <span class="token keyword">if</span><span class="token punctuation">(</span>file<span class="token punctuation">.</span><span class="token function">exists</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> response<span class="token punctuation">.</span><span class="token function">setContentType</span><span class="token punctuation">(</span><span class="token string">"application/forc-download"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> response<span class="token punctuation">.</span><span class="token function">setHeader</span><span class="token punctuation">(</span><span class="token string">"Content-Disposition"</span><span class="token punctuation">,</span><span class="token string">"attachment;filename="</span><span class="token operator">+</span>name<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">try</span> <span class="token punctuation">{</span> outputStream <span class="token operator">=</span> response<span class="token punctuation">.</span><span class="token function">getOutputStream</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> outputStream<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>FileUtils<span class="token punctuation">.</span><span class="token function">readFileToByteArray</span><span class="token punctuation">(</span>file<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> outputStream<span class="token punctuation">.</span><span class="token function">flush</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">finally</span> <span class="token punctuation">{</span> <span class="token keyword">if</span><span class="token punctuation">(</span>outputStream <span class="token operator">!=</span> null<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">try</span> <span class="token punctuation">{</span> outputStream<span class="token punctuation">.</span><span class="token function">close</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">catch</span> <span class="token punctuation">(</span><span class="token class-name">IOException</span> e<span class="token punctuation">)</span> <span class="token punctuation">{</span> e<span class="token punctuation">.</span><span class="token function">printStackTrace</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><h3 id="Spring-MVC-数据校验"><a href="#Spring-MVC-数据校验" class="headerlink" title="Spring MVC 数据校验"></a>Spring MVC 数据校验</h3><p>Spring MVC 提供了两种数据校验的方式：1、基于 Validator 接口。2、使用 Annotation JSR - 303 标准进行校验。</p><p>基于 Validator 接口的方式需要自定义 Validator 验证器，每一条数据的验证规则需要开发者手动完成，使用 Annotation JSR - 303 标准则不需要自定义验证器，通过注解的方式可以直接在实体类中添加每个属性的验证规则，这种方式更加方便，实际开发中推荐使用。</p><blockquote><p>基于 Validator 接口</p></blockquote><ul><li>实体类 Account</li></ul><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>aynu<span class="token punctuation">.</span>entity<span class="token punctuation">;</span><span class="token keyword">import</span> lombok<span class="token punctuation">.</span>Data<span class="token punctuation">;</span><span class="token annotation punctuation">@Data</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Account</span> <span class="token punctuation">{</span> <span class="token keyword">private</span> String name<span class="token punctuation">;</span> <span class="token keyword">private</span> String password<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><ul><li>自定义验证器 AccountValidator，实现 Validator 接口。</li></ul><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>aynu<span class="token punctuation">.</span>validator<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>aynu<span class="token punctuation">.</span>entity<span class="token punctuation">.</span>Account<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>validation<span class="token punctuation">.</span>Errors<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>validation<span class="token punctuation">.</span>ValidationUtils<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>validation<span class="token punctuation">.</span>Validator<span class="token punctuation">;</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">AccountValidator</span> <span class="token keyword">implements</span> <span class="token class-name">Validator</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">boolean</span> <span class="token function">supports</span><span class="token punctuation">(</span>Class<span class="token operator"><</span><span class="token operator">?</span><span class="token operator">></span> aClass<span class="token punctuation">)</span> <span class="token punctuation">{</span> <span class="token keyword">return</span> Account<span class="token punctuation">.</span><span class="token keyword">class</span><span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span>aClass<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@Override</span> <span class="token keyword">public</span> <span class="token keyword">void</span> <span class="token function">validate</span><span class="token punctuation">(</span>Object o<span class="token punctuation">,</span> Errors errors<span class="token punctuation">)</span> <span class="token punctuation">{</span> ValidationUtils<span class="token punctuation">.</span><span class="token function">rejectIfEmpty</span><span class="token punctuation">(</span>errors<span class="token punctuation">,</span><span class="token string">"name"</span><span class="token punctuation">,</span>null<span class="token punctuation">,</span><span class="token string">"姓名不能为空"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> ValidationUtils<span class="token punctuation">.</span><span class="token function">rejectIfEmpty</span><span class="token punctuation">(</span>errors<span class="token punctuation">,</span><span class="token string">"password"</span><span class="token punctuation">,</span>null<span class="token punctuation">,</span><span class="token string">"密码不能为空"</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><ul><li>控制器</li></ul><pre class=" language-java"><code class="language-java"><span class="token keyword">package</span> com<span class="token punctuation">.</span>aynu<span class="token punctuation">.</span>controller<span class="token punctuation">;</span><span class="token keyword">import</span> com<span class="token punctuation">.</span>aynnu<span class="token punctuation">.</span>entity<span class="token punctuation">.</span>Account<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>stereotype<span class="token punctuation">.</span>Controller<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>ui<span class="token punctuation">.</span>Model<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>validation<span class="token punctuation">.</span>BindingResult<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>validation<span class="token punctuation">.</span>annotation<span class="token punctuation">.</span>Validated<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>web<span class="token punctuation">.</span>bind<span class="token punctuation">.</span>annotation<span class="token punctuation">.</span>GetMapping<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>web<span class="token punctuation">.</span>bind<span class="token punctuation">.</span>annotation<span class="token punctuation">.</span>PostMapping<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>springframework<span class="token punctuation">.</span>web<span class="token punctuation">.</span>bind<span class="token punctuation">.</span>annotation<span class="token punctuation">.</span>RequestMapping<span class="token punctuation">;</span><span class="token annotation punctuation">@Controller</span><span class="token annotation punctuation">@RequestMapping</span><span class="token punctuation">(</span><span class="token string">"/validator"</span><span class="token punctuation">)</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">ValidatorHandler</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/login"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> String <span class="token function">login</span><span class="token punctuation">(</span>Model model<span class="token punctuation">)</span><span class="token punctuation">{</span> model<span class="token punctuation">.</span><span class="token function">addAttribute</span><span class="token punctuation">(</span><span class="token string">"account"</span><span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Account</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"login"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token annotation punctuation">@PostMapping</span><span class="token punctuation">(</span><span class="token string">"/login"</span><span class="token punctuation">)</span> <span class="token keyword">public</span> String <span class="token function">login</span><span class="token punctuation">(</span><span class="token annotation punctuation">@Validated</span> Account account<span class="token punctuation">,</span> BindingResult bindingResult<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span><span class="token punctuation">(</span>bindingResult<span class="token punctuation">.</span><span class="token function">hasErrors</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> <span class="token string">"login"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">}</span></code></pre><ul><li>springmvc.xml 配置验证器。</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>bean</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>accountValidator<span class="token punctuation">"</span></span> <span class="token attr-name">class</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>com.aynu.validator.AccountValidator<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>bean</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">mvc:</span>annotation-driven</span> <span class="token attr-name">validator</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>accountValidator<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span><span class="token namespace">mvc:</span>annotation-driven</span><span class="token punctuation">></span></span></code></pre><ul><li>JSP</li></ul><pre class=" language-java"><code class="language-java"><span class="token operator"><</span><span class="token operator">%</span>@ page contentType<span class="token operator">=</span><span class="token string">"text/html;charset=UTF-8"</span> language<span class="token operator">=</span><span class="token string">"java"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ page isELIgnored<span class="token operator">=</span><span class="token string">"false"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ taglib prefix<span class="token operator">=</span><span class="token string">"form"</span> uri<span class="token operator">=</span><span class="token string">"http://www.springframework.org/tags/form"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ taglib prefix<span class="token operator">=</span><span class="token string">"from"</span> uri<span class="token operator">=</span><span class="token string">"http://www.springframework.org/tags/form"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span>html<span class="token operator">></span><span class="token operator"><</span>head<span class="token operator">></span> <span class="token operator"><</span>title<span class="token operator">></span>Title<span class="token operator"><</span><span class="token operator">/</span>title<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>head<span class="token operator">></span><span class="token operator"><</span>body<span class="token operator">></span> <span class="token operator"><</span>form<span class="token operator">:</span>form modelAttribute<span class="token operator">=</span><span class="token string">"account"</span> action<span class="token operator">=</span><span class="token string">"/validator/login"</span> method<span class="token operator">=</span><span class="token string">"post"</span><span class="token operator">></span> 姓名：<span class="token operator"><</span>form<span class="token operator">:</span>input path<span class="token operator">=</span><span class="token string">"name"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>from<span class="token operator">:</span>errors path<span class="token operator">=</span><span class="token string">"name"</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>from<span class="token operator">:</span>errors<span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 密码：<span class="token operator"><</span>form<span class="token operator">:</span>input path<span class="token operator">=</span><span class="token string">"password"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>from<span class="token operator">:</span>errors path<span class="token operator">=</span><span class="token string">"password"</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>from<span class="token operator">:</span>errors<span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"submit"</span> value<span class="token operator">=</span><span class="token string">"登录"</span><span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">:</span>form<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>html<span class="token operator">></span></code></pre><blockquote><p>Annotation JSR - 303 标准</p></blockquote><p>使用 Annotation JSR - 303 标准进行验证，需要导入支持这种标准的依赖 jar 文件，这里我们使用 Hibernate Validator。</p><ul><li>pom.xml</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token comment" spellcheck="true"><!-- JSR-303 --></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.hibernate<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>hibernate-validator<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>5.3.6.Final<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>javax.validation<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>validation-api<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>2.0.1.Final<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>dependency</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>groupId</span><span class="token punctuation">></span></span>org.jboss.logging<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>groupId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>artifactId</span><span class="token punctuation">></span></span>jboss-logging<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>artifactId</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>version</span><span class="token punctuation">></span></span>3.3.2.Final<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>version</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>dependency</span><span class="token punctuation">></span></span></code></pre><ul><li>通过注解的方式直接在实体类中添加相关的验证规则。</li></ul><pre class=" language-java"><code class="language-java"><span class="token keyword">import</span> lombok<span class="token punctuation">.</span>Data<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>hibernate<span class="token punctuation">.</span>validator<span class="token punctuation">.</span>constraints<span class="token punctuation">.</span>Email<span class="token punctuation">;</span><span class="token keyword">import</span> org<span class="token punctuation">.</span>hibernate<span class="token punctuation">.</span>validator<span class="token punctuation">.</span>constraints<span class="token punctuation">.</span>NotEmpty<span class="token punctuation">;</span><span class="token keyword">import</span> javax<span class="token punctuation">.</span>validation<span class="token punctuation">.</span>constraints<span class="token punctuation">.</span>Pattern<span class="token punctuation">;</span><span class="token keyword">import</span> javax<span class="token punctuation">.</span>validation<span class="token punctuation">.</span>constraints<span class="token punctuation">.</span>Size<span class="token punctuation">;</span><span class="token annotation punctuation">@Data</span><span class="token keyword">public</span> <span class="token keyword">class</span> <span class="token class-name">Person</span> <span class="token punctuation">{</span> <span class="token annotation punctuation">@NotEmpty</span><span class="token punctuation">(</span>message <span class="token operator">=</span> <span class="token string">"用户名不能为空"</span><span class="token punctuation">)</span> <span class="token keyword">private</span> String username<span class="token punctuation">;</span> <span class="token annotation punctuation">@Size</span><span class="token punctuation">(</span>min <span class="token operator">=</span> <span class="token number">6</span><span class="token punctuation">,</span>max <span class="token operator">=</span> <span class="token number">12</span><span class="token punctuation">,</span>message <span class="token operator">=</span> <span class="token string">"密码6-12位"</span><span class="token punctuation">)</span> <span class="token keyword">private</span> String password<span class="token punctuation">;</span> <span class="token annotation punctuation">@Email</span><span class="token punctuation">(</span>regexp <span class="token operator">=</span> <span class="token string">"^[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+(\\\\.[a-zA-Z0-9-]+)*\\\\.[a-zA-Z0-9]{2,6}$"</span><span class="token punctuation">,</span>message <span class="token operator">=</span> <span class="token string">"请输入正确的邮箱格式"</span><span class="token punctuation">)</span> <span class="token keyword">private</span> String email<span class="token punctuation">;</span> <span class="token annotation punctuation">@Pattern</span><span class="token punctuation">(</span>regexp <span class="token operator">=</span> <span class="token string">"^((13[0-9])|(14[5|7])|(15([0-3]|[5-9]))|(18[0,5-9]))\\\\\\\\d{8}$"</span><span class="token punctuation">,</span>message <span class="token operator">=</span> <span class="token string">"请输入正确的电话"</span><span class="token punctuation">)</span> <span class="token keyword">private</span> String phone<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><ul><li>ValidatorHandler</li></ul><pre class=" language-java"><code class="language-java"><span class="token annotation punctuation">@GetMapping</span><span class="token punctuation">(</span><span class="token string">"/register"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">register</span><span class="token punctuation">(</span>Model model<span class="token punctuation">)</span><span class="token punctuation">{</span> model<span class="token punctuation">.</span><span class="token function">addAttribute</span><span class="token punctuation">(</span><span class="token string">"person"</span><span class="token punctuation">,</span><span class="token keyword">new</span> <span class="token class-name">Person</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token keyword">return</span> <span class="token string">"register"</span><span class="token punctuation">;</span><span class="token punctuation">}</span><span class="token annotation punctuation">@PostMapping</span><span class="token punctuation">(</span><span class="token string">"/register"</span><span class="token punctuation">)</span><span class="token keyword">public</span> String <span class="token function">register</span><span class="token punctuation">(</span><span class="token annotation punctuation">@Valid</span> Person person<span class="token punctuation">,</span> BindingResult bindingResult<span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">if</span><span class="token punctuation">(</span>bindingResult<span class="token punctuation">.</span><span class="token function">hasErrors</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token keyword">return</span> <span class="token string">"register"</span><span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token keyword">return</span> <span class="token string">"index"</span><span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre><ul><li>springmvc.xml</li></ul><pre class=" language-xml"><code class="language-xml"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span><span class="token namespace">mvc:</span>annotation-driven</span> <span class="token punctuation">/></span></span></code></pre><ul><li>JSP</li></ul><pre class=" language-java"><code class="language-java"><span class="token operator"><</span><span class="token operator">%</span>@ page contentType<span class="token operator">=</span><span class="token string">"text/html;charset=UTF-8"</span> language<span class="token operator">=</span><span class="token string">"java"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ page isELIgnored<span class="token operator">=</span><span class="token string">"false"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">%</span>@ taglib prefix<span class="token operator">=</span><span class="token string">"form"</span> uri<span class="token operator">=</span><span class="token string">"http://www.springframework.org/tags/form"</span> <span class="token operator">%</span><span class="token operator">></span><span class="token operator"><</span>html<span class="token operator">></span><span class="token operator"><</span>head<span class="token operator">></span> <span class="token operator"><</span>title<span class="token operator">></span>Title<span class="token operator"><</span><span class="token operator">/</span>title<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>head<span class="token operator">></span><span class="token operator"><</span>body<span class="token operator">></span> <span class="token operator"><</span>form<span class="token operator">:</span>form modelAttribute<span class="token operator">=</span><span class="token string">"person"</span> action<span class="token operator">=</span><span class="token string">"/validator/register2"</span> method<span class="token operator">=</span><span class="token string">"post"</span><span class="token operator">></span> 用户名：<span class="token operator"><</span>form<span class="token operator">:</span>input path<span class="token operator">=</span><span class="token string">"username"</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">:</span>input<span class="token operator">></span><span class="token operator"><</span>form<span class="token operator">:</span>errors path<span class="token operator">=</span><span class="token string">"username"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 密码：<span class="token operator"><</span>form<span class="token operator">:</span>password path<span class="token operator">=</span><span class="token string">"password"</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">:</span>password<span class="token operator">></span><span class="token operator"><</span>form<span class="token operator">:</span>errors path<span class="token operator">=</span><span class="token string">"password"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 邮箱：<span class="token operator"><</span>form<span class="token operator">:</span>input path<span class="token operator">=</span><span class="token string">"email"</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">:</span>input<span class="token operator">></span><span class="token operator"><</span>form<span class="token operator">:</span>errors path<span class="token operator">=</span><span class="token string">"email"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> 电话：<span class="token operator"><</span>form<span class="token operator">:</span>input path<span class="token operator">=</span><span class="token string">"phone"</span><span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">:</span>input<span class="token operator">></span><span class="token operator"><</span>form<span class="token operator">:</span>errors path<span class="token operator">=</span><span class="token string">"phone"</span><span class="token operator">/</span><span class="token operator">></span><span class="token operator"><</span>br<span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span>input type<span class="token operator">=</span><span class="token string">"submit"</span> value<span class="token operator">=</span><span class="token string">"提交"</span><span class="token operator">/</span><span class="token operator">></span> <span class="token operator"><</span><span class="token operator">/</span>form<span class="token operator">:</span>form<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>body<span class="token operator">></span><span class="token operator"><</span><span class="token operator">/</span>html<span class="token operator">></span></code></pre><p>校验规则详解：</p><p>@Null 被注解的元素必须为null</p><p>@NotNull 被注解的元素不能为null</p><p>@Min(value) 被注解的元素必须是一个数字，其值必须大于等于指定的最小值</p><p>@Max(value) 被注解的元素必须是一个数字，其值必须小于于等于指定的最大值 </p><p>@Email 被注解的元素必须是电子邮箱地址</p><p>@Pattern 被注解的元素必须符合对应的正则表达式</p><p>@Length 被注解的元素的大小必须在指定的范围内</p><p>@NotEmpty 被注解的字符串的值必须非空</p><p>Null 和 Empty 是不同的结果，String str = null，str 是 null，String str = “”，str 不是 null，其值为空。</p>]]></content>
<tags>
<tag> springmvc </tag>
</tags>
</entry>
<entry>
<title>nginx部署前后端分离</title>
<link href="2021/06/04/nginx-bu-shu-qian-hou-duan-fen-chi/"/>
<url>2021/06/04/nginx-bu-shu-qian-hou-duan-fen-chi/</url>
<content type="html"><![CDATA[<h1 id="一-，准备工作"><a href="#一-，准备工作" class="headerlink" title="一 ，准备工作"></a>一 ，准备工作</h1><p>1，把你vue项目中axios的数据地址修改成你的后端项目发布地址!</p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622770617878.png" alt="https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622770617878.png"></p><p>2，在控制台 执行 npm run serve和npm run build，确保程序无误会生成一个dist文件夹</p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622770857437.png" alt="1622770857437"></p><p>3，把这个文件夹通过xshell+sftp丢到你的服务器中</p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622771835274.png" alt="1622771835274"></p><h1 id="二，配置你的nginx"><a href="#二，配置你的nginx" class="headerlink" title="二，配置你的nginx"></a>二，配置你的nginx</h1><p>1，看看你的nginx装在了那里 whereis nginx，进入（如果没有安装nginx，可以看看我的其他博客）</p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622772174267.png" alt="1622772174267"></p><p>2 ，然后用 vi编辑器编辑nginx.conf这个文件，添加相应配置</p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622772316991.png" alt="1622772316991"></p><p>配置上游服务器：</p><pre class=" language-java"><code class="language-java">upstream fruit<span class="token punctuation">{</span> server <span class="token number">120.26</span><span class="token punctuation">.</span><span class="token number">199.203</span><span class="token operator">:</span><span class="token number">8181</span><span class="token punctuation">;</span> <span class="token punctuation">}</span></code></pre><p> server 中配置转发规则：</p><pre class=" language-yml"><code class="language-yml"> location / { proxy_pass http://fruit; proxy_redirect default; }</code></pre><p>配置静态资源访问，root是你的dist位置</p><pre class=" language-yml"><code class="language-yml">location ~ .*\.(js|css|ico|png|jpg|eot|svg|ttf|woff|html|txt|pdf|) { root /usr/local/java/vueproject/fruit/dist/;#所有静态文件直接读取硬盘 expires 30d; #缓存30天 </code></pre><p>3 重新加载配置文件，启动nginx</p><pre class=" language-java"><code class="language-java"><span class="token punctuation">.</span>/nginx <span class="token operator">-</span>s reload 重新加载配置文件</code></pre><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622772795929.png" alt="1622772795929"></p><p>4 确保开放防火墙开启端口80</p><pre class=" language-java"><code class="language-java">firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>list<span class="token operator">-</span>all</code></pre><h1 id="三，外部浏览器访问"><a href="#三，外部浏览器访问" class="headerlink" title="三，外部浏览器访问"></a>三，外部浏览器访问</h1><p>浏览器输入你的IP/index.html</p><p><img src="https://gitee.com/maoshencat/imgpng/raw/master/nginx/1622773063685.png" alt="1622773063685"></p><h3 id="谢谢观看，如有问题，欢迎指正"><a href="#谢谢观看，如有问题，欢迎指正" class="headerlink" title="谢谢观看，如有问题，欢迎指正"></a>谢谢观看，如有问题，欢迎指正</h3>]]></content>
<tags>
<tag> nginx </tag>
<tag> vue </tag>
</tags>
</entry>
<entry>
<title>nginx入门</title>
<link href="2021/06/02/nginx-ru-men/"/>
<url>2021/06/02/nginx-ru-men/</url>
<content type="html"><![CDATA[<h2 id="什么是Nginx？"><a href="#什么是Nginx？" class="headerlink" title="什么是Nginx？"></a>什么是Nginx？</h2><p>Nginx (engine x) 是一个高性能的HTTP和反向代理web服务器，同时也提供了IMAP/POP3/SMTP服务。Nginx是由伊戈尔·赛索耶夫为俄罗斯访问量第二的Rambler.ru站点（俄文：Рамблер）开发的，第一个公开版本0.1.0发布于2004年10月4日。2011年6月1日，nginx 1.0.4发布。</p><p>其特点是占有内存少，并发能力强，事实上nginx的并发能力在同类型的网页服务器中表现较好，中国大陆使用nginx网站用户有：百度、京东、新浪、网易、腾讯、淘宝等。在全球活跃的网站中有12.18%的使用比率，大约为2220万个网站。</p><p>Nginx 是一个安装非常的简单、配置文件非常简洁（还能够支持perl语法）、Bug非常少的服务。Nginx 启动特别容易，并且几乎可以做到7*24不间断运行，即使运行数个月也不需要重新启动。你还能够不间断服务的情况下进行软件版本的升级。</p><p>Nginx代码完全用C语言从头写成。官方数据测试表明能够支持高达 50,000 个并发连接数的响应。</p><h2 id="Nginx作用？"><a href="#Nginx作用？" class="headerlink" title="Nginx作用？"></a>Nginx作用？</h2><blockquote><p>Http代理，反向代理：作为web服务器最常用的功能之一，尤其是反向代理。</p></blockquote><p>正向代理<br><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudy46bdad36-d3e0-43b0-a223-43360b7e8fc7.png" alt="img"><br>反向代理<br><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudy62a15097-6e2a-4dbe-bcf5-f0d7cab81089.png" alt="img"></p><blockquote><p>Nginx提供的负载均衡策略有2种：内置策略和扩展策略。内置策略为轮询，加权轮询，Ip hash。扩展策略，就天马行空，只有你想不到的没有他做不到的。</p></blockquote><p>轮询<br><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudy4d33dfac-1949-4b2d-abb8-fe0b6e65b8dc.png" alt="img"><br>加权轮询<br><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudyb1e3e440-4159-4259-a174-528b56cb04b2.png" alt="img"><br>iphash对客户端请求的ip进行hash操作，然后根据hash结果将同一个客户端ip的请求分发给同一台服务器进行处理，可以解决session不共享的问题。<br><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudy64acb9a3-cd1a-4c0e-a1fa-9b220046a95a.png" alt="img"></p><blockquote><p>动静分离，在我们的软件开发中，有些请求是需要后台处理的，有些请求是不需要经过后台处理的（如：css、html、jpg、js等等文件），这些不需要经过后台处理的文件称为静态文件。让动态网站里的动态网页根据一定规则把不变的资源和经常变的资源区分开来，动静资源做好了拆分以后，我们就可以根据静态资源的特点将其做缓存操作。提高资源响应的速度。</p></blockquote><p><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudyedb1bbd6-e530-4aba-8fde-68658a10e73f.png" alt="img"></p><p>目前，通过使用Nginx大大提高了我们网站的响应速度，优化了用户体验，让网站的健壮性更上一层楼！</p><h1 id="Nginx的安装"><a href="#Nginx的安装" class="headerlink" title="Nginx的安装"></a>Nginx的安装</h1><h2 id="windows下安装"><a href="#windows下安装" class="headerlink" title="windows下安装"></a>windows下安装</h2><p><strong>1、下载nginx</strong></p><p><a href="http://nginx.org/en/download.html">http://nginx.org/en/download.html</a> 下载稳定版本。<br>以nginx/Windows-1.16.1为例，直接下载 nginx-1.16.1.zip。<br>下载后解压，解压后如下：</p><p><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudyb5a1d538-352c-4aa6-88f7-23d18f0588ab.png" alt="img"></p><p><strong>2、启动nginx</strong></p><p>有很多种方法启动nginx</p><p>(1)直接双击nginx.exe，双击后一个黑色的弹窗一闪而过</p><p>(2)打开cmd命令窗口，切换到nginx解压目录下，输入命令 <code>nginx.exe</code> ，回车即可</p><p><strong>3、检查nginx是否启动成功</strong></p><p>直接在浏览器地址栏输入网址 <a href="http://localhost/">http://localhost:80</a> 回车，出现以下页面说明启动成功！</p><p><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudya21688c8-159e-4caa-8e65-3dc056b6b78e.png" alt="img"></p><p><strong>4、配置监听</strong></p><p>nginx的配置文件是conf目录下的nginx.conf，默认配置的nginx监听的端口为80，如果80端口被占用可以修改为未被占用的端口即可。</p><p><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudyf23105c4-b0b2-4e22-a1bf-b8098f40c144.png" alt="img"></p><p>当我们修改了nginx的配置文件nginx.conf 时，不需要关闭nginx后重新启动nginx，只需要执行命令 <code>nginx -s reload</code> 即可让改动生效</p><p><strong>5、关闭nginx</strong></p><p>如果使用cmd命令窗口启动nginx， 关闭cmd窗口是不能结束nginx进程的，可使用两种方法关闭nginx</p><p>(1)输入nginx命令 <code>nginx -s stop</code>(快速停止nginx) 或 <code>nginx -s quit</code>(完整有序的停止nginx)</p><p>(2)使用taskkill <code>taskkill /f /t /im nginx.exe</code></p><pre class=" language-java"><code class="language-java">taskkill是用来终止进程的，<span class="token operator">/</span>f是强制终止 <span class="token punctuation">.</span>/t终止指定的进程和任何由此启动的子进程。<span class="token operator">/</span>im示指定的进程名称 <span class="token punctuation">.</span></code></pre><h2 id="linux下安装"><a href="#linux下安装" class="headerlink" title="linux下安装"></a>linux下安装</h2><p><strong>1、安装gcc</strong></p><p>安装 nginx 需要先将官网下载的源码进行编译，编译依赖 gcc 环境，如果没有 gcc 环境，则需要安装：</p><pre><code>yum install gcc-c++</code></pre><p><strong>2、PCRE pcre-devel 安装</strong></p><p>PCRE(Perl Compatible Regular Expressions) 是一个Perl库，包括 perl 兼容的正则表达式库。nginx 的 http 模块使用 pcre 来解析正则表达式，所以需要在 linux 上安装 pcre 库，pcre-devel 是使用 pcre 开发的一个二次开发库。nginx也需要此库。命令：</p><pre><code>yum install -y pcre pcre-devel</code></pre><p><strong>3、zlib 安装</strong></p><p>zlib 库提供了很多种压缩和解压缩的方式， nginx 使用 zlib 对 http 包的内容进行 gzip ，所以需要在 Centos 上安装 zlib 库。</p><pre class=" language-java"><code class="language-java">yum install <span class="token operator">-</span>y zlib zlib<span class="token operator">-</span>devel</code></pre><p><strong>4、OpenSSL 安装</strong><br>OpenSSL 是一个强大的安全套接字层密码库，囊括主要的密码算法、常用的密钥和证书封装管理功能及 SSL 协议，并提供丰富的应用程序供测试或其它目的使用。<br>nginx 不仅支持 http 协议，还支持 https（即在ssl协议上传输http），所以需要在 Centos 安装 OpenSSL 库。</p><pre class=" language-java"><code class="language-java">yum install <span class="token operator">-</span>y openssl openssl<span class="token operator">-</span>devel</code></pre><p><strong>5、下载安装包</strong></p><p>手动下载.tar.gz安装包，地址：<a href="https://nginx.org/en/download.html">https://nginx.org/en/download.html</a></p><p><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudyf51b946d-fda4-4675-b913-2084e028a5c0.png" alt="img"></p><p>下载完毕上传到服务器上 /root</p><p><strong>6、解压</strong></p><pre class=" language-java"><code class="language-java">tar <span class="token operator">-</span>zxvf nginx<span class="token operator">-</span><span class="token number">1.18</span><span class="token punctuation">.</span><span class="token number">0</span><span class="token punctuation">.</span>tar<span class="token punctuation">.</span>gzcd nginx<span class="token operator">-</span><span class="token number">1.18</span><span class="token punctuation">.</span><span class="token number">0</span></code></pre><p><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudyd8290598-ede7-4b4b-875b-2f447a9c001f.png" alt="img"></p><p><strong>7、配置</strong></p><p>使用默认配置，在nginx根目录下执行</p><pre class=" language-java"><code class="language-java"><span class="token punctuation">.</span>/configuremakemake install</code></pre><p>查找安装路径： <code>whereis nginx</code></p><p><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudyf80f8dc2-d5df-4bc2-933d-6ce11f388f6e.png" alt="img"></p><h2 id="Nginx常用命令"><a href="#Nginx常用命令" class="headerlink" title="Nginx常用命令"></a>Nginx常用命令</h2><pre class=" language-java"><code class="language-java">cd <span class="token operator">/</span>usr<span class="token operator">/</span>local<span class="token operator">/</span>nginx<span class="token operator">/</span>sbin<span class="token operator">/</span><span class="token punctuation">.</span>/nginx 启动<span class="token punctuation">.</span>/nginx <span class="token operator">-</span>s stop 停止<span class="token punctuation">.</span>/nginx <span class="token operator">-</span>s quit 安全退出<span class="token punctuation">.</span>/nginx <span class="token operator">-</span>s reload 重新加载配置文件ps aux<span class="token operator">|</span>grep nginx 查看nginx进程</code></pre><p>启动成功访问 服务器ip:80</p><p><img src="https://kuangstudy.oss-cn-beijing.aliyuncs.com/bbs/2021/01/25/kuangstudyd64b251b-817c-436b-b7a0-57da7bb48cd1.png" alt="img"></p><p>注意：如何连接不上，检查阿里云安全组是否开放端口，或者服务器防火墙是否开放端口！<br>相关命令：</p><pre class=" language-java"><code class="language-java"># 开启service firewalld start# 重启service firewalld restart# 关闭service firewalld stop# 查看防火墙规则firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>list<span class="token operator">-</span>all# 查询端口是否开放firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>query<span class="token operator">-</span>port<span class="token operator">=</span><span class="token number">8080</span><span class="token operator">/</span>tcp# 开放<span class="token number">80</span>端口firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>permanent <span class="token operator">--</span>add<span class="token operator">-</span>port<span class="token operator">=</span><span class="token number">80</span><span class="token operator">/</span>tcp# 移除端口firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>permanent <span class="token operator">--</span>remove<span class="token operator">-</span>port<span class="token operator">=</span><span class="token number">8080</span><span class="token operator">/</span>tcp#重启防火墙<span class="token punctuation">(</span>修改配置后要重启防火墙<span class="token punctuation">)</span>firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>reload# 参数解释<span class="token number">1</span>、firwall<span class="token operator">-</span>cmd：是Linux提供的操作firewall的一个工具；<span class="token number">2</span>、<span class="token operator">--</span>permanent：表示设置为持久；<span class="token number">3</span>、<span class="token operator">--</span>add<span class="token operator">-</span>port：标识添加的端口；</code></pre><h1 id="演示"><a href="#演示" class="headerlink" title="演示"></a>演示</h1><pre class=" language-java"><code class="language-java">upstream lb<span class="token punctuation">{</span> server <span class="token number">127.0</span><span class="token punctuation">.</span><span class="token number">0.1</span><span class="token operator">:</span><span class="token number">8080</span> weight<span class="token operator">=</span><span class="token number">1</span><span class="token punctuation">;</span> server <span class="token number">127.0</span><span class="token punctuation">.</span><span class="token number">0.1</span><span class="token operator">:</span><span class="token number">8081</span> weight<span class="token operator">=</span><span class="token number">1</span><span class="token punctuation">;</span><span class="token punctuation">}</span>location <span class="token operator">/</span> <span class="token punctuation">{</span> proxy_pass http<span class="token operator">:</span><span class="token operator">/</span><span class="token operator">/</span>lb<span class="token punctuation">;</span><span class="token punctuation">}</span></code></pre>]]></content>
<tags>
<tag> nginx </tag>
</tags>
</entry>
<entry>
<title>Linux运维</title>
<link href="2021/05/31/linux-yun-wei/"/>
<url>2021/05/31/linux-yun-wei/</url>
<content type="html"><![CDATA[<h1 id="Linux-系统部署-Java-应用"><a href="#Linux-系统部署-Java-应用" class="headerlink" title="Linux 系统部署 Java 应用"></a>Linux 系统部署 Java 应用</h1><p>服务器 Linux </p><p>阿里云、华为云、腾讯云</p><p>安装虚拟机，虚拟机就是在你的电脑中安装一台虚拟的计算机，内存、CPU、硬盘，Linux 安装到虚拟机中。</p><p>CentOS7，企业级 Linux 的发行版，完全开源，完全免费。</p><p>安装软件：</p><ul><li>虚拟机 VMware workstation 15</li><li>CentOS7</li><li>安装 Java 环境 JDK 8</li><li>安装 MySQL 8</li><li>安装 Tomcat</li><li>安装 Xshell</li><li>安装 Xftp</li></ul><h1 id="安装-VM"><a href="#安装-VM" class="headerlink" title="安装 VM"></a>安装 VM</h1><h1 id="安装-Linux-操作系统-CentOS-7"><a href="#安装-Linux-操作系统-CentOS-7" class="headerlink" title="安装 Linux 操作系统 CentOS 7"></a>安装 Linux 操作系统 CentOS 7</h1><p>1、解压 CentOS7</p><p>2、将解压之后的文件导入 VM，运行即可</p><p>3、虚拟机设置</p><p>默认的网络配置是桥接模式，直接接入当前的网络环境，如果网络不稳定，IP 会变。</p><p>NAT，相当于在 Windows 系统中独立开辟一块新的网络空间，IP 地址固定不变的，无论是否接入外网，都可以访问 CentOS。</p><p>4、启动虚拟机，用 root 权限登录</p><p>用户名：root</p><p>密码：123456</p><p>Linux 查询 IP 地址</p><pre class=" language-java"><code class="language-java">ifconfig</code></pre><h1 id="安装-JDK"><a href="#安装-JDK" class="headerlink" title="安装 JDK"></a>安装 JDK</h1><p>1、删除 CentOS 自带的 OpenJDK</p><p>2、通过 Xftp 将安装包拷贝到 CentOS 中</p><p>3、通过命令安装 JDK</p><pre class=" language-java"><code class="language-java">rpm <span class="token operator">-</span>ivh jdk<span class="token operator">-</span>8u221<span class="token operator">-</span>linux<span class="token operator">-</span>x64<span class="token punctuation">.</span>rpm</code></pre><p>4、配环境变量</p><pre class=" language-java"><code class="language-java">JAVA_HOME<span class="token operator">=</span><span class="token operator">/</span>usr<span class="token operator">/</span>java<span class="token operator">/</span>jdk1<span class="token number">.8</span><span class="token punctuation">.</span>0_221<span class="token operator">-</span>amd64CLASSPATH<span class="token operator">=</span><span class="token operator">%</span>JAVA_HOME<span class="token operator">%</span><span class="token operator">/</span>lib<span class="token operator">:</span><span class="token operator">%</span>JAVA_HOME<span class="token operator">%</span><span class="token operator">/</span>jre<span class="token operator">/</span>libPATH<span class="token operator">=</span>$PATH<span class="token operator">:</span>$JAVA_HOME<span class="token operator">/</span>bin<span class="token operator">:</span>$JAVA_HOME<span class="token operator">/</span>jre<span class="token operator">/</span>binexport PATH CLASSPATH JAVA_HOME</code></pre><p>5、让配置生效</p><pre class=" language-java"><code class="language-java">source <span class="token operator">/</span>etc<span class="token operator">/</span>profile</code></pre><h1 id="Java-Web-应用"><a href="#Java-Web-应用" class="headerlink" title="Java Web 应用"></a>Java Web 应用</h1><p>1、配置 Tomcat</p><p>2、解压缩</p><pre class=" language-java"><code class="language-java">tar <span class="token operator">-</span>zxvf apache<span class="token operator">-</span>tomcat<span class="token operator">-</span><span class="token number">9.0</span><span class="token punctuation">.</span><span class="token number">34</span><span class="token punctuation">.</span>tar<span class="token punctuation">.</span>gz</code></pre><p>3、启动 Tomcat</p><pre class=" language-java"><code class="language-java"><span class="token punctuation">.</span>/startup<span class="token punctuation">.</span>sh</code></pre><p>4、CentOS 开放 8080 端口</p><ul><li>检查防火墙状态</li></ul><pre class=" language-java"><code class="language-java">firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>state</code></pre><p>running 表示防火墙是开启的，如果你看到的是 not running，防火墙关闭，需要开启</p><pre class=" language-java"><code class="language-java">systemctl restart firewalld<span class="token punctuation">.</span>service</code></pre><ul><li>开放 8080 端口</li></ul><pre class=" language-java"><code class="language-java">firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>zone<span class="token operator">=</span><span class="token keyword">public</span> <span class="token operator">--</span>add<span class="token operator">-</span>port<span class="token operator">=</span><span class="token number">8080</span><span class="token operator">/</span>tcp <span class="token operator">--</span>permanent</code></pre><ul><li>重启防火墙</li></ul><pre class=" language-java"><code class="language-java">systemctl restart firewalld<span class="token punctuation">.</span>service</code></pre><ul><li>重新载入配置</li></ul><pre class=" language-java"><code class="language-java">firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>reload</code></pre><h1 id="部署-Spring-Boot-应用"><a href="#部署-Spring-Boot-应用" class="headerlink" title="部署 Spring Boot 应用"></a>部署 Spring Boot 应用</h1><p>IDEA 启动 Spring Boot ，将 Spring Boot 应用打成 jar，通过命令行部署。</p><pre class=" language-java"><code class="language-java">java <span class="token operator">-</span>jar xxx<span class="token punctuation">.</span>jar</code></pre><p>1、将 Spring Boot 应用打包，jar，Maven</p><p>2、通过命令行启动 jar 即可</p><pre class=" language-java"><code class="language-java">java <span class="token operator">-</span>jar demo<span class="token punctuation">.</span>jar</code></pre><h1 id="安装-MySQL"><a href="#安装-MySQL" class="headerlink" title="安装 MySQL"></a>安装 MySQL</h1><p>1、通过 Xftp 将 MySQL 安装包拷贝到 Linux</p><p>2、解压缩</p><pre class=" language-java"><code class="language-java">tar <span class="token operator">-</span>xvf mysql<span class="token operator">-</span><span class="token number">8.0</span><span class="token punctuation">.</span><span class="token number">20</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">.</span>el7<span class="token punctuation">.</span>x86_64<span class="token punctuation">.</span>rpm<span class="token operator">-</span>bundle<span class="token punctuation">.</span>tar </code></pre><p>3、安装 common、libs、client、server</p><p>4、删除自带的 mariadb</p><pre class=" language-java"><code class="language-java">rpm <span class="token operator">-</span>e mariadb<span class="token operator">-</span>libs<span class="token operator">-</span><span class="token number">5.5</span><span class="token punctuation">.</span><span class="token number">44</span><span class="token operator">-</span><span class="token number">2</span><span class="token punctuation">.</span>el7<span class="token punctuation">.</span>centos<span class="token punctuation">.</span>x86_64 <span class="token operator">--</span>nodeps</code></pre><p>5、安装命令行</p><pre class=" language-java"><code class="language-java">rpm <span class="token operator">-</span>ivh mysql<span class="token operator">-</span>community<span class="token operator">-</span>common<span class="token operator">-</span><span class="token number">8.0</span><span class="token punctuation">.</span><span class="token number">20</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">.</span>el7<span class="token punctuation">.</span>x86_64<span class="token punctuation">.</span>rpm <span class="token operator">--</span>nodeps <span class="token operator">--</span>forcerpm <span class="token operator">-</span>ivh mysql<span class="token operator">-</span>community<span class="token operator">-</span>libs<span class="token operator">-</span><span class="token number">8.0</span><span class="token punctuation">.</span><span class="token number">20</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">.</span>el7<span class="token punctuation">.</span>x86_64<span class="token punctuation">.</span>rpm <span class="token operator">--</span>nodeps <span class="token operator">--</span>forcerpm <span class="token operator">-</span>ivh mysql<span class="token operator">-</span>community<span class="token operator">-</span>client<span class="token operator">-</span><span class="token number">8.0</span><span class="token punctuation">.</span><span class="token number">20</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">.</span>el7<span class="token punctuation">.</span>x86_64<span class="token punctuation">.</span>rpm <span class="token operator">--</span>nodeps <span class="token operator">--</span>forcerpm <span class="token operator">-</span>ivh mysql<span class="token operator">-</span>community<span class="token operator">-</span>server<span class="token operator">-</span><span class="token number">8.0</span><span class="token punctuation">.</span><span class="token number">20</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">.</span>el7<span class="token punctuation">.</span>x86_64<span class="token punctuation">.</span>rpm <span class="token operator">--</span>nodeps <span class="token operator">--</span>force</code></pre><p>6、初始化 MySQL</p><pre class=" language-java"><code class="language-java">mysqld <span class="token operator">--</span>initialize</code></pre><p>7、授权防火墙</p><pre class=" language-java"><code class="language-java">chown mysql<span class="token operator">:</span>mysql <span class="token operator">/</span>var<span class="token operator">/</span>lib<span class="token operator">/</span>mysql <span class="token operator">-</span>R<span class="token punctuation">;</span>systemctl start mysqld<span class="token punctuation">.</span>service<span class="token punctuation">;</span>systemctl enable mysqld<span class="token punctuation">;</span></code></pre><p>8、查看数据库的初始化密码</p><pre class=" language-java"><code class="language-java">cat <span class="token operator">/</span>var<span class="token operator">/</span>log<span class="token operator">/</span>mysqld<span class="token punctuation">.</span>log <span class="token operator">|</span> grep password</code></pre><p>9、登录数据库</p><pre class=" language-java"><code class="language-java">mysql <span class="token operator">-</span>uroot <span class="token operator">-</span>p</code></pre><p>10、修改密码</p><pre class=" language-java"><code class="language-java">ALTER USER <span class="token string">'root'</span>@<span class="token string">'localhost'</span> IDENTIFIED WITH mysql_native_password BY <span class="token string">'root'</span><span class="token punctuation">;</span></code></pre><p>11、使用新密码登录</p><p>12、开启远程访问</p><pre class=" language-java"><code class="language-java">create user <span class="token string">'root'</span>@<span class="token string">'%'</span> identified with mysql_native_password by <span class="token string">'root'</span><span class="token punctuation">;</span>grant all privileges on <span class="token operator">*</span><span class="token punctuation">.</span>* to <span class="token string">'root'</span>@<span class="token string">'%'</span> with grant option<span class="token punctuation">;</span>flush privileges<span class="token punctuation">;</span></code></pre><p>13、开放 3306 端口</p><pre class=" language-java"><code class="language-java">firewall<span class="token operator">-</span>cmd <span class="token operator">--</span>zone<span class="token operator">=</span><span class="token keyword">public</span> <span class="token operator">--</span>add<span class="token operator">-</span>port<span class="token operator">=</span><span class="token number">3306</span><span class="token operator">/</span>tcp <span class="token operator">--</span>permanentsystemctl restart firewalld<span class="token punctuation">.</span>servicefirewall<span class="token operator">-</span>cmd <span class="token operator">--</span>reload</code></pre><p>14、MySQL 安装默认使用美国的时区，北京时间比美国晚 8 小时</p><pre class=" language-java"><code class="language-java">set global time_zone<span class="token operator">=</span><span class="token string">'+8:00'</span><span class="token punctuation">;</span></code></pre><p>15、创建数据表</p><pre class=" language-java"><code class="language-java">create database test character set utf8 collate utf8_general_ci<span class="token punctuation">;</span>use test<span class="token punctuation">;</span>create table <span class="token function">user</span><span class="token punctuation">(</span> id <span class="token keyword">int</span> primary key auto_increment<span class="token punctuation">,</span> name <span class="token function">varchar</span><span class="token punctuation">(</span><span class="token number">22</span><span class="token punctuation">)</span><span class="token punctuation">,</span> birthday datetime<span class="token punctuation">)</span><span class="token punctuation">;</span>insert into <span class="token function">user</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> birthday<span class="token punctuation">)</span> <span class="token function">VALUES</span> <span class="token punctuation">(</span><span class="token string">'小明'</span><span class="token punctuation">,</span><span class="token string">'1999-01-01'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>insert into <span class="token function">user</span><span class="token punctuation">(</span>name<span class="token punctuation">,</span> birthday<span class="token punctuation">)</span> <span class="token function">VALUES</span> <span class="token punctuation">(</span><span class="token string">'小红'</span><span class="token punctuation">,</span><span class="token string">'2000-01-01'</span><span class="token punctuation">)</span><span class="token punctuation">;</span></code></pre><p>war jar</p><p>如果你使用的是 SSM 或者 Java WEB（非 Spring Boot）需要通过 war 包进行部署，先把你的应用打成 war 包，丢到外置的 Tomcat 中，启动 Tomcat 服务，进而访问你的应用。</p><p>如果你使用的是 Spring Boot，内置了 Tomcat，直接用 jar 部署，使用命令启动即可</p><pre class=" language-java"><code class="language-java">java <span class="token operator">-</span>jar demo<span class="token punctuation">.</span>jar</code></pre><h1 id="CentOS运行spring-boot程序"><a href="#CentOS运行spring-boot程序" class="headerlink" title="CentOS运行spring boot程序"></a>CentOS运行spring boot程序</h1><pre class=" language-java"><code class="language-java">java <span class="token operator">-</span>jar work3<span class="token operator">-</span><span class="token number">0.0</span><span class="token punctuation">.</span><span class="token number">1</span><span class="token operator">-</span>SNAPSHOT<span class="token punctuation">.</span>jarjava <span class="token operator">-</span>jar work3<span class="token operator">-</span><span class="token number">0.0</span><span class="token punctuation">.</span><span class="token number">1</span><span class="token operator">-</span>SNAPSHOT<span class="token punctuation">.</span>jar <span class="token operator">--</span>server<span class="token punctuation">.</span>port<span class="token operator">=</span><span class="token number">80</span> #指定在<span class="token number">80</span>端口运行ctrl <span class="token operator">+</span> c 停止运行</code></pre><p>后台运行</p><p>1 starpup.sh (启动)</p><pre class=" language-java"><code class="language-java">#<span class="token operator">!</span>bin<span class="token operator">/</span>shnohup java <span class="token operator">-</span>jar <span class="token operator">/</span>usr<span class="token operator">/</span>local<span class="token operator">/</span>java<span class="token operator">/</span>myproject<span class="token operator">/</span>work3<span class="token operator">-</span><span class="token number">0.0</span><span class="token punctuation">.</span><span class="token number">1</span><span class="token operator">-</span>SNAPSHOT<span class="token punctuation">.</span>jar <span class="token operator">&</span> </code></pre><p>2 关闭进程stop.sh</p><pre class=" language-java"><code class="language-java">#<span class="token operator">!</span><span class="token operator">/</span>bin<span class="token operator">/</span>bashPID<span class="token operator">=</span>$<span class="token punctuation">(</span>ps <span class="token operator">-</span>ef <span class="token operator">|</span> grep work3<span class="token operator">-</span><span class="token number">0.0</span><span class="token punctuation">.</span><span class="token number">1</span><span class="token operator">-</span>SNAPSHOT<span class="token punctuation">.</span>jar<span class="token punctuation">.</span>jar <span class="token operator">|</span> grep <span class="token operator">-</span>v grep <span class="token operator">|</span> awk <span class="token string">'{ print $2 }'</span><span class="token punctuation">)</span><span class="token keyword">if</span> <span class="token punctuation">[</span> <span class="token operator">-</span>z <span class="token string">"$PID"</span> <span class="token punctuation">]</span>then echo Application is already stopped<span class="token keyword">else</span> echo kill $PID kill $PIDfi________________________________________ps <span class="token operator">-</span>ef<span class="token operator">|</span>grep java #查看带Java的进程kill pid</code></pre><p>3 重启服务 reboot.sh</p><pre class=" language-java"><code class="language-java">#<span class="token operator">!</span><span class="token operator">/</span>bin<span class="token operator">/</span>bashecho stop applicationsource stop<span class="token punctuation">.</span>shecho start applicationsource startup<span class="token punctuation">.</span>sh</code></pre><p>4 添加可执行权限</p><pre class=" language-java"><code class="language-java">chmod <span class="token operator">+</span>x start<span class="token punctuation">.</span>shchmod <span class="token operator">+</span>x stop<span class="token punctuation">.</span>shchmod <span class="token operator">+</span>x run<span class="token punctuation">.</span>sh</code></pre><p>5 netstat -ntpl|grep java 查看正在运行</p><p>6 firewall-cmd –list-ports 防火墙开启的端口号</p><h1 id="CentOS-防火墙，端口开启命令"><a href="#CentOS-防火墙，端口开启命令" class="headerlink" title="CentOS 防火墙，端口开启命令"></a>CentOS 防火墙，端口开启命令</h1><ol><li><p>查看已打开的端口 # netstat -anp</p></li><li><p>查看想开的端口是否已开 # firewall-cmd –query-port=8003/tcp<br> 若此提示 FirewallD is not running<br> 表示为不可知的防火墙 需要查看状态并开启防火墙</p></li><li><p>查看防火墙状态 # systemctl status firewalld<br> running 状态即防火墙已经开启<br> dead 状态即防火墙未开启</p></li><li><p>开启防火墙，# systemctl start firewalld 没有任何提示即开启成功</p></li><li><p>开启防火墙 # service firewalld start<br> 关闭防火墙 # systemctl stop firewalld<br> centos7.3 上述方式可能无法开启，可以先#systemctl unmask firewalld.service 然后 # systemctl start firewalld.service</p></li><li><p>查看想开的端口是否已开 # firewall-cmd –query-port=8003/tcp 提示no表示未开</p></li><li><p>开永久端口号 firewall-cmd –add-port=8003/tcp –permanent 提示 success 表示成功</p></li><li><p>重新载入配置 # firewall-cmd –reload 比如添加规则之后，需要执行此命令</p></li><li><p>再次查看想开的端口是否已开 # firewall-cmd –query-port=8003/tcp 提示yes表示成功</p></li><li><p>若移除端口 # firewall-cmd –permanent –remove-port=8003/tcp</p></li></ol>]]></content>
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