How to automatically restart a service even if user force close it?

Question

I want a service to run all the time in my application. So I want to restart it even if it is force closed by user. There is definitely a way to do it as apps like facebook are doing it. It's not done using push notification, facebook restarts its service even if internet is off.

Answer 1

First of all, it is really very bad pattern to run service forcefully against the user's willingness.

Anyways, you can restart it by using a BroadcastReceiver which handles the broadcast sent from onDestroy() of your service.

StickyService.java

public class StickyService extends Service
{
    private static final String TAG = "StickyService";


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

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.e(TAG, "onStartCommand");
        return START_STICKY;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        sendBroadcast(new Intent("YouWillNeverKillMe"));
    }

}

RestartServiceReceiver.java

public class RestartServiceReceiver extends BroadcastReceiver
{

    private static final String TAG = "RestartServiceReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.e(TAG, "onReceive");
    context.startService(new Intent(context.getApplicationContext(), StickyService.class));

    }

}

Declare the components in manifest file:

    <service android:name=".StickyService" >
    </service>

    <receiver android:name=".RestartServiceReceiver" >
        <intent-filter>
            <action android:name="YouWillNeverKillMe" >
            </action>
        </intent-filter>
    </receiver>

Start the StickyService in a Component (i.e. Application, Activity, Fragment):

startService(new Intent(this, StickyService.class));

OR

sendBroadcast(new Intent("YouWillNeverKillMe"));

Answer 2

You have to create a sticky service with overriding onTaskRemoved method, where you can set an alarm service to trigger your code again.

public class BackgroundService extends Service {

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        return START_STICKY;
    }

    @Override
    public void onTaskRemoved(Intent rootIntent) {
        //create an intent that you want to start again.
        Intent intent = new Intent(getApplicationContext(), BackgroundService.class);
        PendingIntent pendingIntent = PendingIntent.getService(this, 1, intent, PendingIntent.FLAG_ONE_SHOT);
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        alarmManager.set(AlarmManager.RTC_WAKEUP, SystemClock.elapsedRealtime() + 5000, pendingIntent);
        super.onTaskRemoved(rootIntent);
    }
}

Also in some devices like Xiaomi, Huwaei the app gets force closed once it's removed from recent apps. This is because the manufacturers have task manager features which improve ram/battery performance.

You can check this link for more information: https://stackoverflow.com/a/41360159/2798289