How to schedule an android service to execute at a fixed rate

问题

I am working on an application that should download a file from the network every X seconds to check for any change, I use a service to do that, but its execution is not fixed with the delay time rate, here is my code for the service:

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Toast.makeText(this, "service starting", Toast.LENGTH_SHORT).show();
    checkUpdate();
    return START_STICKY;
}

private Void checkUpdate() {
    timer.scheduleAtFixedRate(new TimerTask() {
            public void run() {
                Log.i("Service", String.valueOf(++counter));
                if(Helper.isNetworkAvailable(getBaseContext())) {
                      // download file
                } else {
                        Log.e("ServiceHandler", "Couldn't get any data from the url");
                    }
                }else {
                    Log.e("Connection", "No connection");
                }
            }
        }, 10000, 10000);
    return null;
}

The output isn't fixed, it is supposed to run every 10 seconds, while running the service run in a random manner

回答1:

How about setting up an AlarmManager within an IntentService? Much more accurate.

 Intent intent = new Intent(context, YourClass.class);
 PendingIntent pi = PendingIntent.getService(context, 0, intent, 0);
 AlarmManager am = (AlarmManager) c.getSystemService(Context.ALARM_SERVICE);
 am.setRepeating(AlarmManager.RTC, System.currentTimeMillis(), 10*1000, pi);

Make sure within YourClass.class (which is an IntentService), put your logic in the handleIntent(Intent intent), which will be called every 10 seconds by the PendingIntent sent by the AlarmManager.

P.S. Update your manifest

Hope it helps

回答2:

Instead of Timer Class, use AlarmManager class. It also performs the same repeating tasks you want. AlamrManager is light weight and it runs even if your device is in sleep mode.

Also see this link Android: How to repeat a service with AlarmManager

回答3:

For repetitive jobs android provides simple api, called Timer please look it. Very simple to use.

回答4:

Try this :

@Override
      public void onStart(Intent intent, int startId) {

          StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
          StrictMode.setThreadPolicy(policy);

            Log.d("Internet Available:  ", ""+flag);

            Calendar cal = Calendar.getInstance();
            cal.add(Calendar.SECOND, 10);

            Intent intent1 = new Intent(this, UpdateWidgetServiceDemo.class);

            PendingIntent pintent = PendingIntent.getService(this, 0, intent1, 0);

            AlarmManager alarm = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
            int i;
            i=15;

            alarm.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), pintent);


        super.onStart(intent, startId);
      }

REMOVE return START_STICKY;

来源：https://stackoverflow.com/questions/20948755/how-to-schedule-an-android-service-to-execute-at-a-fixed-rate

标签

android

android-service