spring mvc 入门例子

以前公司用的是struts，换了家单位，要用spring的MVC框架，赶紧学习一下。

1 先看web.xml的配置

<?xml version="1.0" encoding="UTF-8"?><web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"><display-name>test</display-name><servlet><servlet-name>dispatcher</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>></servlet><servlet-mapping><servlet-name>dispatcher</servlet-name><url-pattern>*.do</url-pattern></servlet-mapping><welcome-file-list><welcome-file>index.jsp</welcome-file></welcome-file-list></web-app>

和struts一样，spring的MVC框架的核心也是一个Servlet，默认会加载/WEB-/INF/${servlet-name}-servlet.xml，也可以加入参数修改

<init-param><param-name>contextConfigLocation</param-name><param-value>/WEB-INF/spring/myServlet.xml</param-value></init-param>

2 dispatcher-servlet.xml配置

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN"        "http://www.springframework.org/dtd/spring-beans-2.0.dtd"><beans default-autowire="byName" default-lazy-init="true"><bean id="simpleUrlHandlerMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"><property name="mappings"><props><prop key="/helloWorld.do">helloWorldController</prop></props></property></bean><bean id="viewResolver"class="org.springframework.web.servlet.view.InternalResourceViewResolver"><property name="viewClass"><value>org.springframework.web.servlet.view.JstlView</value></property><property name="prefix"><value>/WEB-INF/jsp/</value></property><property name="suffix"><value>.jsp</value></property><property name="contentType"><value>text/html;charset=UTF8</value></property></bean><bean id="helloWorldController" class="action.HelloWorldController"></bean></beans>

DispatchServlet接收到请求后会交给SimpleUrlHandlerMapping控制，由哪个Controller处理，Controller类似于Struts的Action，例子中url为/helloWorld.do的请求由helloWorldController这个bean来处理。

3 java文件HelloWorldController.java

实现了Controller接口

public class HelloWorldController implements Controller {public ModelAndView handleRequest(HttpServletRequest arg0,HttpServletResponse arg1) throws Exception {ModelAndView mv = new ModelAndView();mv.setViewName("helloWorld");mv.addObject("name", "linsong");return mv;}}

返回一个ModelAndView对象，ViewName为展现层名字，根据viewResolver配置取得jsp。

4 helloWorld.jsp略

至此，一个简单的spring MVC的例子完成。

接下来深入了解spring MVC的各个组件Controller，HandlerMapping，ViewResolver