SpringMVC入门

Spring Web MVC是一种基于Java的实现了Web MVC设计模式的请求驱动类型的轻量级Web框架，即使用了MVC架构模式的思想，将web层进行职责解耦，基于请求驱动指的就是使用请求-响应模型，框架的目的就是帮助我们简化开发，Spring Web MVC也是要简化我们日常Web开发的。

MVC请求流程

request-------->DispatcherServler(中央调度器/前端控制器)-----> HandlerMapping(处理器映射器)------>返回一个执行链----->

将执行链转交给HandlerAdaptor(处理器适配器)----->调度Handler(处理器)-----> ModelAndView----->先将结果交给HandlerAdaptor，然后再由HandlerAdaptor转交给 DispatcherServler--------->DispatcherServler调度ViewResolver（视图解析器）---->交给DispatcherServler-------> 寻找View---->View做出响应(response)

SpringMVC简单案例

1.引入jar包

2.web.xml的配置：

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
  <display-name></display-name>
  
 
  <!-- 配置中央调度器 -->
  <servlet>
  <servlet-name>springmvc</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  
    <!-- 制定applicationContext.xml的路径 -->
  <init-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath:applicationContext.xml</param-value>
  </init-param>
  <!-- Tomcat启动时servlet对象已经到内存 -->
  <load-on-startup>1</load-on-startup>
  </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>

3.applicationContext.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: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.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.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.xsd">
   
   <bean id="/hello.do" class="cn.happy.controller.MyController"></bean>
   
   <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
   <property name="prefix" value="/WEB-INF/"></property>
   <property name="suffix" value=".jsp"></property>
    </bean>        
 </beans>

4.创建一个Controller

package cn.happy.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 MyController implements Controller{


    /**
     * handleRequest 处理请求
     */
    @Override
    public ModelAndView handleRequest(HttpServletRequest request,
            HttpServletResponse response) throws Exception {
        
        ModelAndView mv=new ModelAndView();
        
        mv.addObject("msg","十一点放学");
        
        mv.setViewName("index");
        return mv;
    }
    
    

}