1.SpringMVC的工作原理

1. 浏览器发出一个http请求给服务器，如果匹配DispatcherServlet的请求映射路径（在web.xml中指定），服务器将请求转交给DispatcherServlet.
2. DipatcherServlet接收到这个请求之后，根据请求的路径，将请求转交给相应的Controller
3. Controller处理后，返回ModelAndView对象（封装跳转页面，要传递的数据）
4. DispatcherServlet根据ViewResolver视图解析器，找到ModelAndView指定的JSP。（ModelAndView只是逻辑视图并不是一个正式的视图）
5. 将JSP显示到浏览器中

2.代码

1.项目目录

2.ApplicationContext-mvc.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:mvc="http://www.springframework.org/schema/mvc"xmlns:p="http://www.springframework.org/schema/p"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
<!-- 如果显示找不到mvc:resources标签而报错的话,可能因为编辑器中的schema过于陈旧,这时将
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd的结尾的3.0改成3.2即可 --><!-- 要扫描的包 --><context:component-scan base-package="org.jsoft.action."/><!-- 启用注解和对对应目录下静态资源的访问 --><mvc:annotation-driven/>	<mvc:resources mapping="/assets/**" location="/assets/"/><!-- 视图解析器 --><bean id="viewResolver"class="org.springframework.web.servlet.view.UrlBasedViewResolver"><property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/><property name="prefix" value="/"/><property name="suffix" value=".jsp"/></bean>
</beans>

3.web.xml

<?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"><welcome-file-list><welcome-file>index.jsp</welcome-file></welcome-file-list><!-- 配置springMVC的servlet --><servlet><servlet-name>springMvc</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><!-- 配置ApplicationContext.xml的路径 --><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:spring/ApplicationContext-mvc.xml</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>springMvc</servlet-name><url-pattern>/</url-pattern></servlet-mapping>
</web-app>

4.vo类

public class Student {private Long id;private String name;private Integer age;/**getter and setter*/
}

5.C层StudentAction

import java.io.PrintWriter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.json.JSONObject;
import org.jsoft.vo.Student;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;@Controller
@RequestMapping("studentAction")
public class StudentAction {//方法一,返回的是一个字符串,根据视图解析器,会自动在前面加上/,在后面加上".jsp",在访问这个jsp页面@RequestMapping("/login")public String login(){System.out.println("StudentAction.login()");return "index";}//方法二,返回一个最常用的ModelAndView,里面可以添加要传向浏览器的数据和页面@RequestMapping("/register")public ModelAndView register(){Student student = new Student();student.setAge(50);student.setName("PinkFloyd");student.setId(1L);ModelAndView mv = new ModelAndView();mv.setViewName("register");//设置返回的页面mv.addObject("student", student);//添加键值对形式的返回数据mv.addObject("firstName", "David");mv.addObject("lastName", "Gilmour");return mv;}//方法三,需要接受页面数据时可以在方法的参数里添加request和response@RequestMapping("/update")//这是Ajax形式的请求public void update(HttpServletRequest request,HttpServletResponse response) throws Exception{request.setCharacterEncoding("UTF-8");response.setCharacterEncoding("UTF-8");Student student = new Student();String id = request.getParameter("id");String name = request.getParameter("name");String age = request.getParameter("age");student.setAge(new Integer(age));student.setName(name);student.setId(new Long(id));PrintWriter out = response.getWriter();out.print(JSONObject.fromObject(student).toString());//已json的形式返回}
}

6.V层register.jsp

<%@ 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 'register.jsp' starting page</title><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">--><script type="text/javascript" src="assets/js/jquery-1.10.1.js"></script></head><body>Register.jsp <br/>Welcome!${student.id},${student.age},${student.name}乐队的<%=request.getAttribute("firstName") %>  ${lastName}<form id="f">乐队id:<input name="id" value="${student.id}"/>乐队年龄:<input name="age" value="${student.age}"/>乐队名称:<input name="name" value="${student.name}"/><input id="btn" type="button" value="修改"></form><script type="text/javascript" >$(function(){$("#btn").click(function(){$.ajax({url:"studentAction/update",type:"post",data:$("#f").serialize(),dataType:"json",success : function(msg){alert(msg.name);}})})});</script></body>
</html>