JSON的实现，即将需要的数据回传到jsp页面；
1>.加入实现Json的三个架包到lib中；
2>.目标方法上边加入注解，需要返回的值
3>.在jsp页面中书写jQuery方法；
eclipse中javaEE环境下的web.xml文件配置为：
<?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_2_5.xsd"
id="WebApp_ID" version="2.5"> <!-- 配置SpringMVC的DispatcherServlet -->
<servlet>
<servlet-name>springDispatcherServlet</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>springDispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping> <!-- 配置 HiddenHttpMethodFilter: 把 POST 请求转为 DELETE、PUT 请求 -->
<filter>
<filter-name>HiddenHttpMethodFilter</filter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter> <filter-mapping>
<filter-name>HiddenHttpMethodFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping> </web-app>
spring的bean的配置文件为：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:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
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-4.0.xsd"> <!-- 配置自动扫描的包 -->
<context:component-scan base-package="com.atguigu.springmvc"></context:component-scan> <!-- 配置视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"></property>
<property name="suffix" value=".jsp"></property>
</bean> <!--
default-servlet-handler 将在 SpringMVC 上下文中定义一个 DefaultServletHttpRequestHandler,
它会对进入 DispatcherServlet 的请求进行筛查, 如果发现是没有经过映射的请求, 就将该请求交由 WEB 应用服务器默认的
Servlet 处理. 如果不是静态资源的请求，才由 DispatcherServlet 继续处理 一般 WEB 应用服务器默认的 Servlet 的名称都是 default.
若所使用的 WEB 服务器的默认 Servlet 名称不是 default，则需要通过 default-servlet-name 属性显式指定 -->
<mvc:default-servlet-handler/> <!-- 一般都会配置这个 <mvc:annotation-driven ></mvc:annotation-driven>，
由于。。。requestmapping请求实现不了，使用这个，会使requestmapping请求一定实现
-->
<mvc:annotation-driven></mvc:annotation-driven> </beans>
EmployeeDao类：
package com.atguigu.springmvc.crud.dao; import java.util.Collection;
import java.util.HashMap;
import java.util.Map; import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository; import com.atguigu.springmvc.crud.entities.Department;
import com.atguigu.springmvc.crud.entities.Employee; @Repository//标识持久层组件
public class EmployeeDao { private static Map<Integer, Employee> employees=null; @Autowired
private DepartmentDao departmentDao;
static{
employees=new HashMap<Integer, Employee>(); employees.put(1001, new Employee(1001, "E-AA", "aa@163.com", 1, new Department(101, "D-AA")));
employees.put(1002, new Employee(1002, "E-BB", "bb@163.com", 1, new Department(102, "D-BB")));
employees.put(1003, new Employee(1003, "E-CC", "cc@163.com", 0, new Department(103, "D-CC")));
employees.put(1004, new Employee(1004, "E-DD", "dd@163.com", 0, new Department(104, "D-DD")));
employees.put(1005, new Employee(1005, "E-EE", "ee@163.com", 1, new Department(105, "D-EE")));
} private static Integer initId=1006; //添加数据的方法
public void save(Employee employee){
if(employee.getId()==null){
employee.setId(initId++);
} employee.setDepartment(departmentDao.getDepartment(employee.getDepartment().getId()));
employees.put(employee.getId(), employee);
} //获取全部的数据的方法
public Collection<Employee> getAll(){
return employees.values();
} //获取集合中的一个数据
public Employee getEmployee(Integer id){
return employees.get(id);
} //删除集合中的一个数据
public void delect(Integer id){
employees.remove(id);
}
}
实现的handler 类方法：SpringMVCTest:
@Controller
public class SpringMVCTest { @Autowired
private EmployeeDao employeeDao;/*
* JSON的实现，即将需要的数据回传到jsp页面；
* 1>.加入实现Json的三个架包到lib中；
* 2>.目标方法上边加入注解，需要返回的值
* 3>.在jsp页面中书写jQuery方法；
* */
@ResponseBody
@RequestMapping("/testJson")
public Collection<Employee> testJson(){
return employeeDao.getAll();
} }
jsp页面：index.jsp；需要导入jQuery架包，并且用jQuery方法，实现数据回显到jsp页面；点击
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="scripts/jquery-1.9.1.min.js"></script>
<script type="text/javascript">
$(function(){
$("#testJson").click(function(){
var url=this.href;
var args={}; $.post(url,args,function(data){
for(var i=0;i<data.length;i++){
var id=data[i].id;
var lastName=data[i].lastName;
alert(id+":"+lastName);
}
});
});
}) </script>
</head>
<body> <a href="testJson" id="testJson">Test Json</a>
<br><br> </body>
</html>