Spring Mvc 输出 Json

http://blog.csdn.net/liuxiit/article/details/6618573

************************************************************服务器端代码**************************************************************************

Spring Web MVC(Servlet) 具体细节就不说了，比较不一样的地方，下面会注明！

1. web.xml 的内容如下:

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<?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" id="WebApp_ID" version="2.5">

<display-name>FCAS</display-name>

<servlet>

<servlet-name>foodcenter</servlet-name>

<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

<load-on-startup>1</load-on-startup>

</servlet>

<servlet-mapping>

<servlet-name>foodcenter</servlet-name>

<url-pattern>*.json</url-pattern>

</servlet-mapping>

</web-app>

2. foodcenter-servlet.xml 的内容如下：

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<?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:context="http://www.springframework.org/schema/context"

xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:annotation-config/>

<!-- Controller 类的注解标识-->

<context:component-scan base-package="com.liuxi.foodcenter.controller"/>

<!--这个ViewResolver 的具体原来没细究，不过CV战士们 中的一员，这样用是没问题的(参考官文) -->

<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver">

<property name="mediaTypes">

<map>

<entry key="json" value="application/json"/> <!-- 告诉视图解析器 返回的类型为json 格式 -->

</map>

</property>

<property name="defaultViews">

<list>

<!-- 这个 View 比较重要,ModelAndView 里的数据变成JSON -->

<bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView">

</bean>

</list>

</property>

</bean>

<!--真正的项目，业务Bean 有专门对应的配置文件，这里为了简单起见，就写在这里了 -->

<bean id="foodService" class="com.liuxi.food.service.FoodServiceImpl"/>

</beans>

3. 子控制器FindFoodListController.java

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package com.liuxi.foodcenter.controller;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.beans.factory.annotation.Qualifier;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

import org.springframework.web.servlet.ModelAndView;

import com.liuxi.bean.Food;

import com.liuxi.food.service.IFoodService;

@Controller

public class FindFoodListController {

@Autowired @Qualifier("foodService")

private IFoodService foodService;

/** 根据餐菜的类别返回 该类别下的所有菜*/

@RequestMapping("/findFoodList")

public ModelAndView queryFoodList(@RequestParam("typeId") int typeId){

List<Food> list=foodService.getFoodListByType(typeId);

ModelAndView modelView=new ModelAndView();

Map<String,Object> modelMap=new HashMap<String,Object>();

modelMap.put("FOOD_LIST", list);

modelMap.put("TYPE_ID", typeId);

modelView.addAllObjects(modelMap);

return modelView;

}

}

4. FoodServiceImpl.java

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package com.liuxi.food.service;

import java.util.ArrayList;

import java.util.List;

import com.liuxi.bean.Food;

public class FoodServiceImpl implements IFoodService{

@Override

public List<Food> getFoodListByType(int typeId) {

//这里本来要调DAO层接口的，这边暂时写死

Food food1=new Food(1,1,"鱼香肉丝", 12.00,"好吃的不得了-鱼香肉丝",4.5,5.0);

Food food2=new Food(2,1,"农家小炒肉", 15.00,"好吃的不得了-农家小炒肉",3.7,4.3);

Food food3=new Food(3,1,"韭菜炒蛋", 10.00,"好吃的不得了-韭菜炒蛋",2.6,3.0);

Food food4=new Food(4,1,"回锅肉", 13.00,"好吃的不得了-回锅肉",3.1,3.8);

Food food5=new Food(5,1,"宫保鸡丁", 14.00,"好吃的不得了-宫保鸡丁",3.7,5.0);

Food food6=new Food(6,1,"苦瓜炒蛋", 9.00,"好吃的不得了-宫保鸡丁",4.9,4.7);

Food food7=new Food(7,1,"莴笋肉片", 10.00,"好吃的不得了-莴笋肉片",2.6,3.9);

List<Food> list=new ArrayList<Food>();

list.add(food1);

list.add(food2);

list.add(food3);

list.add(food4);

list.add(food5);

list.add(food6);

list.add(food7);

return list;

}

}

5.IFoodService.java

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package com.liuxi.food.service;

import java.util.List;

import com.liuxi.bean.Food;

public interface IFoodService {

List<Food> getFoodListByType(int typeId);

}

6.Food.java

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package com.liuxi.bean;

public class Food {

private int id; // ID

private String name; // 菜名

private double price; // 价格

private String notes; // 菜的简要介绍

private int foodTypeId; // 菜所属的类别

private double kouWeiScore; // 口味的分值

private double hotLevel; // 星级别

public Food(int id, int foodTypeId, String name, double price,

String notes, double kouWeiScore, double hotLevel) {

this.id = id;

this.name = name;

this.price = price;

this.notes = notes;

this.foodTypeId = foodTypeId;

this.kouWeiScore = kouWeiScore;

this.hotLevel = hotLevel;

}

public Food() {

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public double getPrice() {

return price;

}

public void setPrice(double price) {

this.price = price;

}

public String getNotes() {

return notes;

}

public void setNotes(String notes) {

this.notes = notes;

}

public int getFoodTypeId() {

return foodTypeId;

}

public void setFoodTypeId(int foodTypeId) {

this.foodTypeId = foodTypeId;

}

public double getKouWeiScore() {

return kouWeiScore;

}

public void setKouWeiScore(double kouWeiScore) {

this.kouWeiScore = kouWeiScore;

}

public double getHotLevel() {

return hotLevel;

}

public void setHotLevel(double hotLevel) {

this.hotLevel = hotLevel;

}

public String toString() {

return id + "--" + name + "--" + price + "--" + notes + "--"

+ foodTypeId + "--" + kouWeiScore + "--" + hotLevel;

}

}

7.Spring Web MVC 中 将ModelAndView 中的数据自动转换成json ，靠的是jackjson 中 连个jar 包 (这个下载大本营里有下,花了我2积分哦)

jackson-core-asl-1.4.2.jar

jackson-mapper-asl-1.4.2.jar

*************************************以上是服务器端代码，已全部贴完!**********************************************

访问链接是: http://192.168.1.104:8088/FCAS/findFoodList.json?typeId=1
***************************************************************************Android 客户端 访问部分************************************************************

下面进入 Android 客户端访问部分(这里暂不贴 界面，用android 的单元测试 来 测试 服务器返回的json 数据是什么样的

8. GetFoodListTest.java

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package com.liuxi.takeorder.test;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.util.ArrayList;

import org.apache.http.HttpResponse;

import org.apache.http.HttpStatus;

import org.apache.http.NameValuePair;

import org.apache.http.client.HttpClient;

import org.apache.http.client.entity.UrlEncodedFormEntity;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.http.message.BasicNameValuePair;

import android.test.AndroidTestCase;

import android.util.Log;

public class GetFoodListTest extends AndroidTestCase {

private static final String TAG="GetFoodListTest";

public void testFindFoodList() {

String uri="http://192.168.1.104:8088/FCAS/findFoodList.json?typeId=1";

try{

HttpClient httpClient=new DefaultHttpClient();

//HttpPost 实现 HttpUriRequest 接口,HttpUriRequest接口 继承 HttpRequest

HttpPost httpPostReq=new HttpPost(uri);

ArrayList<NameValuePair> paramList=new ArrayList<NameValuePair>();

NameValuePair param1=new BasicNameValuePair("typeId",String.valueOf(1));

paramList.add(param1);

httpPostReq.setEntity(new UrlEncodedFormEntity(paramList));

HttpResponse resp=httpClient.execute(httpPostReq);

if(resp.getStatusLine().getStatusCode()==HttpStatus.SC_OK){

BufferedReader reader=new BufferedReader(

new InputStreamReader(resp.getEntity().getContent())

);

StringBuffer result=new StringBuffer();

String inputLine=null;

while((inputLine=reader.readLine())!=null){

result.append(inputLine);

}

Log.i(TAG, result.toString());

}

}catch(Exception e){

Log.i(TAG,e.getMessage());

}

}

}



9. 激动人心的时刻-----> 结果是啥？

日志记录为:

07-19 16:12:53.282: INFO/GetFoodListTest(1287): {"TYPE_ID":1,"FOOD_LIST":[{"name":"鱼香肉丝","id":1,"price":12.0,"notes":"好吃的不得了-鱼香肉丝","foodTypeId":1,"kouWeiScore":4.5,"hotLevel":5.0},{"name":"农家小炒肉","id":2,"price":15.0,"notes":"好吃的不得了-农家小炒肉","foodTypeId":1,"kouWeiScore":3.7,"hotLevel":4.3},{"name":"韭菜炒蛋","id":3,"price":10.0,"notes":"好吃的不得了-韭菜炒蛋","foodTypeId":1,"kouWeiScore":2.6,"hotLevel":3.0},{"name":"回锅肉","id":4,"price":13.0,"notes":"好吃的不得了-回锅肉","foodTypeId":1,"kouWeiScore":3.1,"hotLevel":3.8},{"name":"宫保鸡丁","id":5,"price":14.0,"notes":"好吃的不得了-宫保鸡丁","foodTypeId":1,"kouWeiScore":3.7,"hotLevel":5.0},{"name":"苦瓜炒蛋","id":6,"price":9.0,"notes":"好吃的不得了-宫保鸡丁","foodTypeId":1,"kouWeiScore":4.9,"hotLevel":4.7},{"name":"莴笋肉片","id":7,"price":10.0,"notes":"好吃的不得了-莴笋肉片","foodTypeId":1,"kouWeiScore":2.6,"hotLevel":3.9}]}

我把上面{} 里的东西 放到一个foodlist.json 文件中，格式化后的内容如下：

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{

"TYPE_ID" : 1,

"FOOD_LIST" : [{

"name" : "鱼香肉丝",

"id" : 1,

"price" : 12.0,

"notes" : "好吃的不得了-鱼香肉丝",

"foodTypeId" : 1,

"kouWeiScore" : 4.5,

"hotLevel" : 5.0

}, {

"name" : "农家小炒肉",

"id" : 2,

"price" : 15.0,

"notes" : "好吃的不得了-农家小炒肉",

"foodTypeId" : 1,

"kouWeiScore" : 3.7,

"hotLevel" : 4.3

}, {

"name" : "韭菜炒蛋",

"id" : 3,

"price" : 10.0,

"notes" : "好吃的不得了-韭菜炒蛋",

"foodTypeId" : 1,

"kouWeiScore" : 2.6,

"hotLevel" : 3.0

}, {

"name" : "回锅肉",

"id" : 4,

"price" : 13.0,

"notes" : "好吃的不得了-回锅肉",

"foodTypeId" : 1,

"kouWeiScore" : 3.1,

"hotLevel" : 3.8

}, {

"name" : "宫保鸡丁",

"id" : 5,

"price" : 14.0,

"notes" : "好吃的不得了-宫保鸡丁",

"foodTypeId" : 1,

"kouWeiScore" : 3.7,

"hotLevel" : 5.0

}, {

"name" : "苦瓜炒蛋",

"id" : 6,

"price" : 9.0,

"notes" : "好吃的不得了-宫保鸡丁",

"foodTypeId" : 1,

"kouWeiScore" : 4.9,

"hotLevel" : 4.7

}, {

"name" : "莴笋肉片",

"id" : 7,

"price" : 10.0,

"notes" : "好吃的不得了-莴笋肉片",

"foodTypeId" : 1,

"kouWeiScore" : 2.6,

"hotLevel" : 3.9

}]

}

10. OK! 返回数据正确。

************************************************Spring 是用ObjectMapper 将 数据转换成json 数据的*****************************

下面自己写了个转换的例子:

ObjectMapperTest.java

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package com.bean.test;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import org.codehaus.jackson.map.ObjectMapper;

public class ObjectMapperTest {

/**

* @param args

*/

public static void main(String[] args) throws Exception {

ObjectMapper mapper=new ObjectMapper();

Map<String,Object> foodListData=new HashMap<String,Object>();

List list=new ArrayList();

Map<String,Object> foodData=new HashMap<String,Object>();

foodData.put("id", 1);

foodData.put("name", "鱼香肉丝");

foodData.put("price", 12.00);

foodData.put("notes", "好吃啊，真的!");

foodData.put("kouWeiScore", 4.5);

foodData.put("hotLevel", 5.0);

list.add(foodData);

foodListData.put("foodlist", list);

String str=mapper.writeValueAsString(foodListData);

System.out.println(str);

}

}

上述程序输出的是:

{"foodlist":[{"id":1,"kouWeiScore":4.5,"price":12.0,"hotLevel":5.0,"name":"鱼香肉丝","notes":"好吃啊，真的!"}]}

format 下：

{

"foodlist" : [{

"id" : 1,

"kouWeiScore" : 4.5,

"price" : 12.0,

"hotLevel" : 5.0,

"name" : "鱼香肉丝",

"notes" : "好吃啊，真的!"

}]

}

好吧，就到这里了。基本架子搭好，接着，就用这个架子来 实现 Android 客户端+Spring MVC 去做后面的项目。继续挖矿。。。。