json Gson

package com.example.volleylearn;

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

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.test.AndroidTestCase;
import android.util.Log;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

/*
1. 将json格式的字符串{}转换为Java对象, 使用原生API
2. 将json格式的字符串{}转换为Java对象, 使用GSON
3. 将json格式的字符串[]转换为Java对象的List, 使用原生API
4. 将json格式的字符串[]转换为Java对象的List, 使用GSON

5. 将Java对象转换为json字符串{}, 使用GSON
6. 将Java对象的List转换为json字符串[], 使用GSON
 */
public class JsonTest extends AndroidTestCase{

    /*
     * 1. 将json格式的字符串{}转换为Java对象, 使用原生API
     */
    public void testJsonToObject() throws JSONException {
        String jsonString = "{\"id\":2, \"name\":\"大虾\", \"price\":12.3,\"imagePath\":\"http://192.168.10.165:8080/L05_Server/images/f1.jpg\"}";
        
        //将json字符串封装为JSONObject对象
        JSONObject jsonObject = new JSONObject(jsonString);
        //从对象中根据key得到对应的value
        int id = jsonObject.getInt("id");
        String name = jsonObject.getString("name");
        double price = jsonObject.getDouble("price");
        String imagePath = jsonObject.getString("imagePath");
        //封装ShopInfo对象
        ShopInfo shopInfo = new ShopInfo(id, name, price, imagePath);
        
        Log.e("TAG", shopInfo.toString());
    }
    
    /*
     * 1. 将json格式的字符串{}转换为Java对象, 使用GSON
     */
    public void testJsonToObject2()  {
        String jsonString = "{\"id\":3, \"name\":\"大虾\", \"price\":12.3,\"imagePath\":\"http://192.168.10.165:8080/L05_Server/images/f1.jpg\"}";
        
        ShopInfo shopInfo = new Gson().fromJson(jsonString, ShopInfo.class);
        
        Log.e("TAG", shopInfo.toString());
    }
    
    
    /*
     * 3. 将json格式的字符串[]转换为Java对象的List, 使用原生API
     */
    public void testJsonToList() throws JSONException {
        String jsonString = "[{\"id\":3, \"name\":\"大虾\", \"price\":12.3,\"imagePath\":\"http://192.168.10.165:8080/L05_Server/images/f1.jpg\"},"
                + "{\"id\":5, \"name\":\"大虾2\", \"price\":128.3,\"imagePath\":\"http://192.168.10.165:8080/L05_Server/images/f2.jpg\"}]";
        List<ShopInfo> list = new ArrayList<ShopInfo>();
        
        //1. 将json字符串包装JSONArray对象
        JSONArray jsonArray = new JSONArray(jsonString);
        //2. 遍历JSONArray对象所有元素(JSONObject), 并将每个元素封装为shopInfo, 并添加到List
        for(int i=0;i<jsonArray.length();i++) {
            JSONObject jsonObject = jsonArray.getJSONObject(i);
            //从对象中根据key得到对应的value
            int id = jsonObject.getInt("id");
            String name = jsonObject.getString("name");
            double price = jsonObject.getDouble("price");
            String imagePath = jsonObject.getString("imagePath");
            //封装ShopInfo对象
            ShopInfo shopInfo = new ShopInfo(id, name, price, imagePath);
            list.add(shopInfo);
        }
        
        Log.e("TAG", list.toString());
    }
    
    /*
     * 4. 将json格式的字符串[]转换为Java对象的List, 使用GSON
     */
    public void testJsonToList2() throws JSONException {
        String jsonString = "[{\"id\":4, \"name\":\"大虾\", \"price\":12.3,\"imagePath\":\"http://192.168.10.165:8080/L05_Server/images/f1.jpg\"},"
                + "{\"id\":6, \"name\":\"大虾2\", \"price\":128.3,\"imagePath\":\"http://192.168.10.165:8080/L05_Server/images/f2.jpg\"}]";
        
        List<ShopInfo> list = new Gson().fromJson(jsonString, new TypeToken<List<ShopInfo>>(){}.getType());
        
        Log.e("TAG", list.toString());
    }
    
    /*
        5. 将Java对象转换为json字符串{}, 使用GSON
    */
    public void testObjectToJson() {
        ShopInfo info = new ShopInfo(3, "KK", 1000, "http://www.sina.com");
        String json = new Gson().toJson(info);
        Log.e("TAG", json);
    }
    
    
    /*
        6. 将Java对象的List转换为json字符串[], 使用GSON
    */
    
    public void testListToJson() {
        
        List<ShopInfo> list = new ArrayList<ShopInfo>();
        list.add(new ShopInfo(3, "KK", 1000, "http://www.sina.com"));
        list.add(new ShopInfo(4, "KK2", 2000, "http://www.sina.com222"));
        
        String json = new Gson().toJson(list);
        
        Log.e("TAG", json);
    }
    
    public void testJsonToMap() {
        String jsonString = "{\"my name\":\"大虾\", \"1\":12}";
        Map<String, Object> map = new Gson().fromJson(jsonString, new TypeToken<Map<String, Object>>(){}.getType());
        Log.e("TAG", map.toString());
    }
}