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