springMVC框架下返回json格式的对象，list，map

原文地址：http://liuzidong.iteye.com/blog/1069343

注意这个例子要使用jQuery，但是jquery文件属于静态的资源文件，所以要在springMVC中设置静态资源访问

web.xml

<?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>SpringMVCFile</display-name>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.js</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.css</url-pattern>
    </servlet-mapping>
    <!-- 配置前台分发器 -->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!-- 扫描使用springmvc配置文件 -->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc-context.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>
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>
</web-app>

springMVC的配置文件

<?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:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 扫描包裹，我们完全使用注释定义 Bean 并完成 Bean 之间装配： -->
    <context:component-scan base-package="com.fileUpDown" />
    <!-- 解决了@Controller注解的使用前提配置。 -->
    <mvc:annotation-driven />
    <!-- 配置对静态资源的处理 -->
    <!-- mapping是映射路径，location是本地属性就是webcontent下的目录，web-inf可能访问不到 -->
    <mvc:resources mapping="/file/**" location="/fileHome/" />

    <!-- 定义view视图解析器 -->
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass"
            value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/" />
        <property name="suffix" value=".jsp" />
    </bean>
    <bean
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <bean
                    class="org.springframework.http.converter.StringHttpMessageConverter">
                    <property name="supportedMediaTypes">
                        <list>
                            <value>text/html;charset=UTF-8</value>
                        </list>
                    </property>
                </bean>
            </list>
        </property>
    </bean>
    <bean id="mappingJacksonHttpMessageConverter"
        class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" />
    <!-- 设置文件上传的一些属性 -->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver"
        p:defaultEncoding="UTF-8" />
</beans>

前台的界面

<%@ page language="java" contentType="text/html; charset=UTF-8"  pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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">
    <%-- <script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery/jquery-1.4.4.min.js"></script> --%>
    <script type="text/javascript" src="${pageContext.request.contextPath}/jquery-1.11.0.min.js"></script>
    <title>Spring MVC - jQuery 整合教程</title>
</head>
<body>
<h3>Spring MVC - jQuery 整合教程</h3>
<h4>AJAX version</h4>
<p>Demo 1 计算并返回值</p>
<div style="border: 1px solid #ccc; width: 250px;">
    Add Two Numbers: <br/>
    <input id="inputNumber1" type="text" size="5"> +
    <input id="inputNumber2" type="text" size="9">
    <input type="submit" id="demo1" value="Add" /> <br/>
    Sum: <br>
    <span id="sum">(Result will be shown here)</span>
</div>
<hr><br>
<p>Demo 2 获取一个对象</p>
<div style="border: 1px solid #ccc; width: 250px;">
    <select id="userId">
        <c:forEach var="index" begin="1" end="5" step="1">
            <option value="${index}">${index}</option>
        </c:forEach>
    </select>
    <input type="submit" id="demo2" value="Get" /> <br/>
    <span id="info">(Result will be shown here)</span>
</div>
<hr><br>
<p>Demo 3 返回List集合对象</p>
<div style="border: 1px solid #ccc; width: 250px;">
    <input type="submit" id="demo3" value="Get List User" /> <br/>
    <span id="listInfo">(Result will be shown here)</span>
</div>
<hr><br>
<p>Demo 4 返回Map集合对象</p>
<div style="border: 1px solid #ccc; width: 250px;">
    <input type="submit" id="demo4" value="Get Map User" /> <br/>
    <span id="mapInfo">(Result will be shown here)</span>
</div>
<hr><br>
<a href="${pageContext.request.contextPath}/index.jsp">返回</a>
<hr><br>

<script type="text/javascript">
$(function() {
     $("#demo1").click(function(){
         //当demo1发生点击事件后，对/main/ajax/add.do发送请求，把传递的数据以json的形式传递，
         //请求完成后使用function(data)函数，把结果显示到页面上来
        $.post("${pageContext.request.contextPath}/main/ajax/add.do",
                    {inputNumber1:  $("#inputNumber1").val(),
                     inputNumber2:  $("#inputNumber2").val()
                    },

                    function(data){
                        $("#sum").replaceWith('<span id="sum">'+ data + '</span>');
                    });
     });

      $("#demo2").click(function(){
        var userId = $("#userId").val();
        $.post("${pageContext.request.contextPath}/main/ajax/getUser/"+userId+".do",
                    null,
                    function(data){
                        var info = "姓名: " + data.name+",年龄: " + data.age + ",地址: " + data.address + ",性别: " + (data.sex == 1 ? "男" : "女")+",密码: " + data.password;
                        $("#info").html(info);
                    });
     });

      $("#demo3").click(function(){
        $.post("${pageContext.request.contextPath}/main/ajax/userList.do",
                    null,
                    function(data){
                            var info = '';
                             $.each(data,function(index,entity) {
                               info += "姓名: " + entity.name+",年龄: " + entity.age + ",地址: " + entity.address + ",性别: " + (entity.sex == 1 ? "男" : "女")+",密码: " + entity.password+"<br>";
                             });
                             $("#listInfo").html(info);
                    });
     });     

     $("#demo4").click(function(){
        $.post("${pageContext.request.contextPath}/main/ajax/userMap.do",
                    null,
                    function(map){
                         var info = '';
                         $.each(map,function(key,values) {
                               info += "key="+key+"<br>";
                               $(values).each(function(){
                                   info += "姓名: " + this.name+",年龄: " + this.age + ",地址: " + this.address + ",性别: " + (this.sex == 1 ? "男" : "女")+",密码: " + this.password+"<br>";
                                });    

                         });
                         $("#mapInfo").html(info);
                    });
     });     

});
</script>
</body>
</html>

com.fileUpDown包下的action jqueryJsonAction.Java

package com.fileUpDown;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import com.springMVC.javaBean.User;

@Controller
@RequestMapping("/main/ajax")
public class jqueryJsonAction {
    /**
     * 根据映射跳转到指定的页面
     */
    @RequestMapping(value = "/add", method = RequestMethod.GET)
    public String getAjaxAddPage() {
        // 跳转到ajax-add-page
        return "ajax-add-page";
    }

    /**
     * 提交表单并进行运算.
     */
    @RequestMapping(value = "/add", method = RequestMethod.POST)
    public @ResponseBody Integer add(@RequestParam(value = "inputNumber1", required = true) Integer inputNumber1,
            @RequestParam(value = "inputNumber2", required = true) Integer inputNumber2) {
        // 实现运算
        Integer sum = inputNumber1 + inputNumber2;
        System.out.println("sum: " + sum);
        // @ResponseBody 会自动的将返回值转换成JSON格式
        // 但是你必须添加jackson的jar包!!!
        return sum;
    }

    @RequestMapping(value = "/getUser/{userId}", method = RequestMethod.POST)
    /**
     * @ResponseBody注解用于将Controller的方法返回的对象，通过适当的HttpMessageConverter转换为指定格式后，
     * 写入到Response对象的body数据区 使用的时候Controller返回的不是界面的时候，是json或者xml
     */
    /**
     * 当使用@RequestMapping URI template 样式映射时， 即 someUrl/{paramId},
     * 这时的paramId可通过 @Pathvariable注解绑定它传过来的值到方法的参数上。
     */
    public @ResponseBody User getUser(@PathVariable("userId") String userId) {
        System.out.println("根据ID获取用户对象: " + userId);
        Map<String, User> users = new HashMap<String, User>();
        users.put("1", new User("123456", "李逵", "123", "成都市", "1", 23));
        users.put("2", new User("565676", "张三", "123", "北京市", "2", 53));
        users.put("3", new User("325566", "李四", "123", "河南省", "2", 93));
        users.put("4", new User("989654", "刘邦", "123", "蒙古包", "1", 13));
        users.put("5", new User("234444", "王熙凤", "123", "成都市", "1", 43));
        return users.get(userId);
    }

    @RequestMapping(value = "/userList", method = RequestMethod.POST)
    public @ResponseBody List<User> getUsers() {
        List<User> users = new ArrayList<User>();
        users.add(new User("123456", "李逵", "123", "成都市", "1", 23));
        users.add(new User("123457", "李四", "124", "北京市", "2", 53));
        users.add(new User("123458", "李三", "125", "河南市", "0", 73));
        users.add(new User("123459", "李五", "126", "大路市", "3", 93));
        return users;
    }
    @RequestMapping(value="/userMap",method = RequestMethod.POST)
    public @ResponseBody Map<String,User> getMap(){
        Map<String,User> map = new HashMap<String,User>();
        for(int i=0;i<4;i++){
            map.put(""+i, new User("123456", "李逵", "123", "成都市", "1", i+23));
        }
        return map;
    }
}

javaBean对象

package com.springMVC.javaBean;

public class User {
    private String num;
    private String name;
    private String password;
    private String address;
    private String sex;
    private int age;
    public User(String num, String name, String password, String address, String sex, int age) {
        super();
        this.num = num;
        this.name = name;
        this.password = password;
        this.address = address;
        this.sex = sex;
        this.age = age;
    }
    public String getNum() {
        return num;
    }
    public void setNum(String num) {
        this.num = num;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }

}