How to run service in background like WhatsApp does for taking backup of the chat without wake up device?

Question

In my application, I need to do some task at midnight of the everyday. I achieved this using AlarmManager and service, but when my task starts it wakeup the device and launches the app. How can I do that like WhatsApp in the background?

Answer 1

service used for it.

You have create another class then, you have extend Service

public class service extends Service {

// declaring object of MediaPlayer
private MediaPlayer player;

public service() {
}
@Override
public int onStartCommand(Intent intent, int flags, int startId){
    onTaskRemoved(intent);
    Toast.makeText(getApplicationContext(),"This is a Service running in Background",
            Toast.LENGTH_SHORT).show();
    player = MediaPlayer.create(getApplicationContext(),R.raw.ringtone);
    player.start();
    startForegroundService(intent);
    return START_STICKY;
}

@Override
public IBinder onBind(Intent intent) {
    // TODO: Return the communication channel to the service.
    throw new UnsupportedOperationException("Not yet implemented");
}
@Override
public void onTaskRemoved(Intent rootIntent) {
    Intent restartServiceIntent = new Intent(getApplicationContext(),this.getClass());
    restartServiceIntent.setPackage(getPackageName());
    startService(restartServiceIntent);
    super.onTaskRemoved(rootIntent);
}
@Override
public ComponentName startForegroundService(final Intent service) {
    return startForegroundService(service);
}
}

To run the source code you have write

Intent intent = new Intent(this, service.class);
ContextCompat.startForegroundService(this,intent);

Alternatively, you can use

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

Sometimes above source code works in background in API level 22. Sometimes it gives error. Sometimes it doesn't work.

Here's the git repo