SpringMVC的三种处理器适配器

SpringMVC具有三种处理器适配器，他们分别是BeanNameUrlHandlerMapping、SimpleControllerHandlerAdapter、ControllerClassNameHandlerMapping，可以分别使用这三种处理器适配器进行获取Controller。

程序结构如下：

首先，来介绍BeanNameUrlHandlerMapping映射，如下所示，这种映射使用Bean的name来访问控制器，它根据类名（Mycontroller）类名.do来访问，类名首字母小写。

（1）写UserController.java类

package com.zk.UserController;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;
 
public class UserController implements Controller{
 
    public ModelAndView handleRequest(HttpServletRequest request,
            HttpServletResponse response) throws Exception {
        // TODO Auto-generated method stub
        // 接受请求，接受参数，验证参数
                // 封装参数，调用业务方法
                // 返回视图
         
        ModelAndView mv=new ModelAndView();
        //设置页面回显数据
        mv.addObject("hello", "凤姐喜欢你");
        //指定跳转视图，返回物理视图
        //mv.setViewName("/index.jsp");
        //返回逻辑视图
        mv.setViewName("index");
        return mv;
    }
 
}

（2）写一个index.jsp界面

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    <title>My JSP 'index.jsp' starting page</title>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
  </head>
  <body>
    ${hello }
  </body>
</html>

（3）写web.xml页面

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <display-name>Spring_002</display-name>
  <servlet>
  <servlet-name>springmvc</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <!-- 
  Spring 默认加载SpringMVC的配置文件，这个需要满足一下规则：
  命名规则：Servlet-name-servlet.xml========>SpringMVC-servlet.xml
  路径规范SpringMVC-serlvet.xml必须放在WEB-INF下
   -->
   <init-param>
   <param-name>contextConfigLocation</param-name>
   <param-value>/WEB-INF/config/springmvc.xml</param-value>   
   </init-param>
  </servlet>  
  <servlet-mapping>
  <servlet-name>springmvc</servlet-name>
  <url-pattern>*.do</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

（4）SpringMVC.xml配置BeanNameUrlHandlerMapping

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
<bean id="userController" name="/hello.do" class="com.zk.UserController.UserController"></bean> 
<!-- 配置处理器映射器 -->
<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
</beans>

运行结果如下所示：

（2）其次，来介绍SimpleControllerHandlerAdapter映射，寻找Controller 。根据浏览器url匹配简单url的key，key又Controller的id找到Controller。

更改SpringMVC.xml文件，配置一个SimpleControllerHandlerAdapter映射。

SpringMVC.xml配置文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/aop
         http://www.springframework.org/schema/aop/spring-aop.xsd
         http://www.springframework.org/schema/tx
         http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
          <bean id="userController" name="/hello.do" class="com.zk.UserController.UserController"></bean>
         <!-- url进行集中配置 -->
         <bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
         <property name="mappings">
         <props>
         <prop key="/min.do">userController</prop>
         <prop key="/abc.do">userController</prop>
         <prop key="/ss.do">userController</prop>
         </props>
         </property>
         </bean>
         <!-- 配置处理器适配器:负责执行UserController,springMVC默认处理器适配器 -->
         <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean>
         <bean class="com.zk.UserController.UserController"></bean>
          
         <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
         <property name="prefix" value="/WEB-INF/jsp/"></property>
         <property name="suffix" value=".jsp"></property>
         </bean>
</beans>

运行结果：

（3）最后来介绍ControllerClassNameHandlerMapping，寻找Controller，根据类名（MyController）类名.do来访问,类名首字母小写。更改SpringMVC.xml文件，配置一个ControllerClassNameHandlerMapping。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
     xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/aop
         http://www.springframework.org/schema/aop/spring-aop.xsd
         http://www.springframework.org/schema/tx
         http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
         <!-- 通过类名.do来访问，类名首字母小写 -->
         <bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping"></bean>
         <bean class="com.zk.UserController.UserController"></bean>
         <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
         <property name="prefix" value="/WEB-INF/jsp/"></property>
         <property name="suffix" value=".jsp"></property>
         </bean>     
</beans>