android 學習之json數據的解析與創建

json數據格式已經是互聯網數據通信的標準格式了，各種後端語言都支持json數據的處理，重要的是json格式具有輕便，靈活，語言清晰特點，android也完美的實現對json數據格式的解析；安卓下面對json數據格式解析有兩種，JSONObject類實現和谷歌提供的Gson解析；這裏以官方JSONObject來說明

現在項目assets目錄下新建一個json文件，test.json

{
	"languages":[
	 	{"id":1,"ide":"Eclipse","name":"java"},
	 	{"id":2,"ide":"PhpStorm","name":"php"},
	 	{"id":3,"ide":"Visual Studio","name":"asp.net"}
	],
	"cat":"it"


}

回到MainActivity當中實現

package com.example.testjson;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

import java.io.*;

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

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		
		try {
			InputStreamReader isr = new InputStreamReader(getAssets().open("test.json"),"UTF-8");
			
			BufferedReader br =new BufferedReader(isr);
			
			StringBuilder sb =new StringBuilder();
			String line="";
			
			while((line=br.readLine())!=null){
				sb.append(line);
			}
			
			try {
				JSONObject root =new JSONObject(sb.toString());
				String cat =root.getString("cat");
				System.out.println("cat鍵結果是："+cat);
				
				JSONArray arr= root.getJSONArray("languages");
				for(int i=0;i<arr.length();i++){
					JSONObject obj =arr.getJSONObject(i);
					System.out.println("第個"+i+"對象，屬性爲："+"id="+obj.getInt("id")+",ide="+obj.getString("ide")+",name="+obj.getString("name"));
				}
				
				
				JSONArray jarray = new JSONArray();
				JSONObject newobj =new JSONObject();
				
				JSONObject obj1 =new JSONObject();
				obj1.put("company", "韻達");
				obj1.put("praise", "很垃圾");
				obj1.put("star", 0);
				
				JSONObject obj2 =new JSONObject();
				obj2.put("company", "圓通");
				obj2.put("praise", "一般");
				obj2.put("star", 3);
				
				JSONObject obj3 =new JSONObject();
				obj3.put("company", "順豐");
				obj3.put("praise", "速度很快！");
				obj3.put("star", 5);
				
				jarray.put(obj1);
				jarray.put(obj2);
				jarray.put(obj3);
				
				newobj.put("wuliu", jarray);
				newobj.put("theme", "物流");
				System.out.println("新構造的json對象爲："+newobj.toString());
				
			} catch (JSONException e) {
				e.printStackTrace();
			}
			
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

}