import android.app.Activity;

 import android.content.Intent;

 import android.os.Bundle;

 public class MainActivity extends Activity {

     @Override

     protected void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);

         setContentView(R.layout.activity_main);

         startService(new Intent(getApplicationContext(),PushService.class));

     }

 }

 import java.util.List;

 import android.app.ActivityManager;

 import android.app.ActivityManager.RunningServiceInfo;

 import android.app.Service;

 import android.content.Intent;

 import android.os.IBinder;

 public class PushService extends Service {

     @Override

     public void onCreate() {

         // TODO Auto-generated method stub

         super.onCreate();

         new SeekServiceThread().start();

     }

     @Override

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

         return Service.START_STICKY;//绮樻�Service鏍囪瘑锛屽綋Service缁勪欢鍦ㄩ潪鎰忔効鏃惰鍋滄鍚庯紝鏈夋満鐜囬噸鍚�

         }

     @Override

     public IBinder onBind(Intent intent) {

         // TODO Auto-generated method stub

         return null;

     }

     //鏌ユ壘褰撳墠缁勪欢鐨勭嚎绋嬶紝濡傛灉褰撳墠姝ｈ繍琛岀殑鏈嶅姟缁勪欢涓嶅寘鍚玃ushService缁勪欢鏃讹紝鍒欏惎鍔�

     class SeekServiceThread extends Thread{

         @Override

         public void run() {

             while(true){

                 //1.鑾峰彇Activity缁勪欢绠＄悊鍣紙绠＄悊褰撳墠搴旂敤鐨勮繘绋嬨�鏈嶅姟缁勪欢銆佷换鍔℃垨鍥為�鏍堬級

                 ActivityManager mgr=(ActivityManager) getSystemService(ACTIVITY_SERVICE);

                 //2. 鑾峰彇姝ｈ繍琛岀殑鏈嶅姟缁勪欢

                 List<RunningServiceInfo> rServices = mgr.getRunningServices(100);

                 boolean isFinded=false;//鏍囪瘑鏄惁鏌ユ壘鍒板綋鍓嶇殑service缁勪欢

                 for(RunningServiceInfo rService:rServices){

                     if(rService.getClass().getName().equals(PushService.class.getName())){

                         isFinded=true;

                     }

                 }

                 if(!isFinded){ //濡傛灉娌℃湁鏌ユ壘鍒帮紝鍒欏惎鍔ㄦ湰鏈嶅姟缁勪欢

                     startService(new Intent(getApplicationContext(),PushService.class));

                 }

                 try {

                     Thread.sleep(2000);

                 } catch (InterruptedException e) {

                     e.printStackTrace();

                 }

             }

         }

     }

 }