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。。。。