android之后台定时更新ui天气【Timer、service、broadcast、activity】

这个案例只是为了关联各个知识点，在实际开发中还有待优化

 项目结构分析：

Weather实体类：用来存放我们的天气实体

WeatherManager: 用来操作Weather

MainActivity:主acaitivy

CityWeatherService:定时轮询来更新前台的信息

原理比较简单直接贴出代码：

Weather:

package com.example.weatherdemo;

public class Weather
{

    private String cityName;
    private String cityData;
    private String cityWeath;
    private String cityWinder;
    private String cityImg;

    public Weather(){

    }
    public Weather(String cityName,String cityData,String cityWeath,String cityWinder,String cityImg){
        this.cityName = cityName;
        this.cityData = cityData;
        this.cityWeath = cityWeath;
        this.cityWinder = cityWinder;
        this.cityImg = cityImg;
    }

    public String getCityName()
    {
        return cityName;
    }
    public void setCityName(String cityName)
    {
        this.cityName = cityName;
    }
    public String getCityData()
    {
        return cityData;
    }
    public void setCityData(String cityData)
    {
        this.cityData = cityData;
    }
    public String getCityWeath()
    {
        return cityWeath;
    }
    public void setCityWeath(String cityWeath)
    {
        this.cityWeath = cityWeath;
    }
    public String getCityWinder()
    {
        return cityWinder;
    }
    public void setCityWinder(String cityWinder)
    {
        this.cityWinder = cityWinder;
    }
    public String getCityImg()
    {
        return cityImg;
    }
    public void setCityImg(String cityImg)
    {
        this.cityImg = cityImg;
    }




}

WeatherManager:

package com.example.weatherdemo;

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

public class WeatherManager
{

    Weather weather;

    public void setWeather(String jsonString){
        try
        {
            JSONObject jsonObject = new JSONObject( jsonString );
            JSONObject object = jsonObject.getJSONObject( "weatherinfo" );
            String cityName = object.getString( "city" );
            String cityData = object.getString( "date_y" );
            String cityWeath = object.getString( "weather1" );
            String cityWinder = object.getString( "wind1" );
            String cityImg = object.getString( "img1" );
            weather = new Weather( cityName, cityData, cityWeath, cityWinder, cityImg );
        }
        catch (JSONException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public Weather getWeather(){
        return weather;
    }

}

CityWeatherService:

package com.example.weatherdemo;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Timer;
import java.util.TimerTask;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.util.Log;

public class CityWeatherService extends Service
{
    private static final int UPDATAWEATHER = 0X10;

    private final int GOTOBROADCAST = 0X20;

    public static final String BROADCASTACTION = "com.jone.broad";

    Timer timer;


    @Override
    public IBinder onBind(Intent arg0)
    {
        // TODO Auto-generated method stub
        return null;
    }


    @Override
    public int onStartCommand(Intent intent, int flags, int startId)
    {

        // updateWeather();
        timer = new Timer();
        timer.schedule( new TimerTask()
        {

            @Override
            public void run()
            {
                // 定时更新
                String jsonString = getWeather();
                // 发送广播
                Intent intent = new Intent();
                intent.setAction( BROADCASTACTION );
                intent.putExtra( "jsonstr", jsonString );
                sendBroadcast( intent );
//               Message msg = handler.obtainMessage();
//               msg.what = UPDATAWEATHER;
//               handler.sendMessage( msg );

            }
        }, 0, 20 * 1000 );

        return super.onStartCommand( intent, flags, startId );
    }


    private String getWeather()
    {

        String srsString = "";
        try
        {
            srsString = getJsonStringGet( "http://m.weather.com.cn/data/101250101.html" );
        }
        catch (Exception e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
            Log.i( "tag",e.getMessage() );
        }

        return srsString;
    }


    public String getJsonStringGet(String uri) throws Exception
    {
        String result = null;
        URL url = new URL( uri );
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setConnectTimeout( 6 * 1000 );// 设置连接超时
        Log.i( "msg", conn.getResponseCode() + "???????" );
        if (conn.getResponseCode() == 200)
        {
            Log.i( "msg", "成功" );
            InputStream is = conn.getInputStream();// 得到网络返回的输入流
            result = readData( is, "UTF-8" );
        }
        else
        {
            Log.i( "msg", "失败" );
            result = "";
        }
        conn.disconnect();
        return result;

    }


    private String readData(InputStream inSream, String charsetName) throws Exception
    {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = -1;
        while ((len = inSream.read( buffer )) != -1)
        {
            outStream.write( buffer, 0, len );
        }
        byte[] data = outStream.toByteArray();
        outStream.close();
        inSream.close();
        return new String( data, charsetName );
    }


    @Override
    public void onDestroy()
    {
        // TODO Auto-generated method stub
        super.onDestroy();
        if(timer != null){
            timer.cancel();
        }
    }

}

MainActivity:

package com.example.weatherdemo;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity
{

    BroadcastMain  broadcastMain ;
    Weather weather;
    public static WeatherManager manager;

    TextView cityTextView;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.activity_main );

        cityTextView = (TextView) findViewById( R.id. city);
        manager = new WeatherManager();
        Intent intent = new Intent();
        intent.setClass(this, CityWeatherService.class);
        startService(intent);
        broadcastMain = new BroadcastMain();
        IntentFilter filter = new IntentFilter();
        filter.addAction( CityWeatherService.BROADCASTACTION );
        registerReceiver( broadcastMain, filter );

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu)
    {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate( R.menu.main, menu );
        return true;
    }

    public class BroadcastMain extends BroadcastReceiver{
        @Override
        public void onReceive(Context context, Intent intent)
        {
//          String jsonString = intent.getExtras().getString( "jsonstr" );
//          manager.setWeather( jsonString );
            Message msg = handler.obtainMessage();
            msg.what = 01;
            handler.sendMessage( msg );
        }
    }



    Handler handler = new Handler()
    {
        public void handleMessage(android.os.Message msg)
        {
            switch (msg.what)
            {
                case 01:
                    weather = manager.getWeather();
                    cityTextView.setText( weather.getCityName() );
                    break;

                default:
                    break;
            }

        };

    };
    @Override
    protected void onDestroy()
    {

        Intent intent = new Intent();
        intent.setClass(this, CityWeatherService.class);
        stopService(intent);
        super.onDestroy();
    }


}

主要的功能实现在service中，开启一个定时器，去获取服务端的信息，通过广播来实时我们的activity中相关的组件