springmvc两种非注解的处理器适配器

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">
    <display-name>springmvc_01</display-name>

    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>*.action</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

java源代码

package com.zhou.controller;

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 AccountController implements Controller{

    @Override
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.setViewName("index.jsp");
        modelAndView.addObject("account", "122553");
        return modelAndView;
    }

}

package com.zhou.controller;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.HttpRequestHandler;

public class UserController implements HttpRequestHandler{

    public String login(){
        return null;
    }

    @Override
    public void handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setAttribute("user", "zhangsan");
        request.getRequestDispatcher("index.jsp").forward(request, response);
    }

}

springmvc.xml

<?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:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.2.xsd">

    <!-- 配置处理器映射器 -->
    <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean>

    <!-- 配置处理器适配器 -->
    <!-- 以bean的name属性值作为url -->
    <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean>
    <!-- 另一个处理器适配器 -->
    <bean class="org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter">

    </bean>
    <!-- 以bean的id属性值作为url -->
    <bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
        <property name="mappings">
            <props>
                <prop key="/user1.action">user</prop>
                <prop key="/user2.action">user</prop>
                <prop key="/account.action">account</prop>
            </props>
        </property>
    </bean>
    <!-- 配置视图解析器 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"></bean>

    <!-- controller -->
    <bean id="user" name="/user.action" class="com.zhou.controller.UserController"></bean>

    <bean id="account" class="com.zhou.controller.AccountController"></bean>
</beans>  

org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter这个适配器是处理实现了

org.springframework.web.servlet.mvc.Controller接口的handler,如下代码可以解释

public boolean supports(Object handler) {
        return (handler instanceof Controller);
    }

org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter这个适配器是处理实现了

org.springframework.web.HttpRequestHandler接口的handler,如下代码可以解释

因此非注解的handler要实现处理器适配器相对应需要的接口，才能被适配器匹配到。