Android 客户端通过内置API（HttpClient) 访问 服务器(用Spring MVC 架构) 返回的json数据全过程

************************************************************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:

<?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：

<?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

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

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

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

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

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：

{
"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

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。。。。