json数据解析

package com.itheima.json;

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

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

import com.itheima.json.utils.StreamTool;





import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

    private EditText ed_city;
    private TextView city_result1;
    private TextView city_result2;
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        ed_city = (EditText) findViewById(R.id.ed_city);
        city_result1 = (TextView) findViewById(R.id.city_result1);
        city_result2 = (TextView) findViewById(R.id.city_result2);
    }
    
    private final static String PATH = "http://wthrcdn.etouch.cn/weather_mini?city=";
    
    protected static final int SUCCESS = 0;
    protected static final int INVALID_CITY = 1;
    protected static final int ERROR = 2;

    private String city;
    String ul;
    
    private Handler mHandler = new Handler(){
        
        public void handleMessage(android.os.Message msg) {
            
            switch (msg.what) {
            case SUCCESS:
                
                try {
                    JSONArray data = (JSONArray) msg.obj;
                    String day01 = data.getString(0);
                    city_result1.setText(day01);
                    
                    String day02 = data.getString(1);
                    city_result2.setText(day02);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                
                break;
            case INVALID_CITY:
                Toast.makeText(MainActivity.this, "城市无效 ...", 0).show();
                break;
            case ERROR:
                
                Toast.makeText(MainActivity.this, "网络 问题 .... ...", 0).show();
                break;

            default:
                break;
            }
        };
    };
    
    public void searchCityWeather(View v){
        
        city = ed_city.getText().toString().trim();
        if(TextUtils.isEmpty(city)){
            Toast.makeText(this, "路径错误...", 0).show();
            return;
        }
        
        //http://wthrcdn.etouch.cn/weather_mini?city=%E6%B7%B1%E5%9C%B3
        
        // 发起请求 给 那个 网站了 
        new Thread(){
            public void run() {
                
                try {
                    
                    ul = PATH + URLEncoder.encode(city, "UTF-8");
                    URL url = new URL(ul);
                    
                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                    
                    // 设置 必要的参数信息
                    conn.setConnectTimeout(5000);
                    conn.setRequestMethod("GET");
                    
                    //判断 响应码 
                    int code = conn.getResponseCode();
                    
                    if(code==200){
                        
                        InputStream in = conn.getInputStream();
                        String data = StreamTool.decodeStream(in);
                        
                        System.out.println(data);
                        
                        //解析json 格式的数据 
                        JSONObject jsonObj = new JSONObject(data);
                        
                        // 获得 desc 的值 
                        String result = jsonObj.getString("desc");
                        if("OK".equals(result)){
                            
                            //城市 有效, 返回了需要的数据
                            JSONObject dataObj = jsonObj.getJSONObject("data");
                            
                            JSONArray jsonArray = dataObj.getJSONArray("forecast");
                            
                            //通知 更新 ui 
                            Message msg = Message.obtain();
                            msg.obj = jsonArray;
                            msg.what=SUCCESS;
                            mHandler.sendMessage(msg);
                            
                        /*    String value1 = jsonArray.getString(0);
                            String value2 = jsonArray.getString(2);
                            System.out.println(value1);
                            System.out.println(value2);*/
                            in.close();
                        }else{
                            
                            //城市 无效
                            Message msg = Message.obtain();
                            msg.what=INVALID_CITY;
                            mHandler.sendMessage(msg);
                        }
                    }
                    
                } catch (Exception e) {
                    e.printStackTrace();
                    
                    Message msg = Message.obtain();
                    msg.what=ERROR;
                    mHandler.sendMessage(msg);
                }
                
            };
        }.start();
        
    }
    
}

package com.itheima.json.weather.utils;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class StreamTool {

    public static String decodeStream(InputStream in) throws IOException {
        
        // 底层流
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        
        int len =0;
        byte[] buf = new byte[1024];
        
        while((len=in.read(buf))>0){
            baos.write(buf, 0, len);
        }
        
        String data = baos.toString();
        
        return data;
    }

}