Cannot keep android service alive after app is closed

Here is an example of foreground service that I use and that works, it remains active when the app is closed. Of course, it also must be started, and for that task the app must be running at a first glance, or a receiver of a boot event must be set, but this is another story.

public class MyService extends Service {
static final int NOTIFICATION_ID = 543;

public static boolean isServiceRunning = false;

@Override
public void onCreate() {
    super.onCreate();
    startServiceWithNotification();
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    if (intent != null && intent.getAction().equals(C.ACTION_START_SERVICE)) {
        startServiceWithNotification();
    }
    else stopMyService();
    return START_STICKY;
}

// In case the service is deleted or crashes some how
@Override
public void onDestroy() {
    isServiceRunning = false;
    super.onDestroy();
}

@Override
public IBinder onBind(Intent intent) {
    // Used only in case of bound services.
    return null;
}


void startServiceWithNotification() {
    if (isServiceRunning) return;
    isServiceRunning = true;

    Intent notificationIntent = new Intent(getApplicationContext(), MyActivity.class);
    notificationIntent.setAction(C.ACTION_MAIN);  // A string containing the action name
    notificationIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
    PendingIntent contentPendingIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);

    Bitmap icon = BitmapFactory.decodeResource(getResources(), R.drawable.my_icon);

    Notification notification = new NotificationCompat.Builder(this)
            .setContentTitle(getResources().getString(R.string.app_name))
            .setTicker(getResources().getString(R.string.app_name))
            .setContentText(getResources().getString(R.string.my_string))
            .setSmallIcon(R.drawable.my_icon)
            .setLargeIcon(Bitmap.createScaledBitmap(icon, 128, 128, false))
            .setContentIntent(contentPendingIntent)
            .setOngoing(true)
//                .setDeleteIntent(contentPendingIntent)  // if needed
            .build();
    notification.flags = notification.flags | Notification.FLAG_NO_CLEAR;     // NO_CLEAR makes the notification stay when the user performs a "delete all" command
    startForeground(NOTIFICATION_ID, notification);
}

void stopMyService() {
    stopForeground(true);
    stopSelf();
    isServiceRunning = false;
}
}

Then I run it with

    Intent startIntent = new Intent(getApplicationContext(), MyService.class);
    startIntent.setAction(C.ACTION_START_SERVICE);
    startService(startIntent);

Please note the two constants used as Actions, these are Strings that must start with the package name.

IntentService

Using IntentService is probably not the best approach. By default IntentService stops itself after onHandleIntent(Intent) returns and there's no work left to do (i.e. the request queue is empty). This is explained in the official docs of IntentService:

When all requests have been handled, the IntentService stops itself, so you should not call stopSelf().

In your case, onHandleIntent(Intent) creates a thread but returns right away, which makes it stop by itself.

Service + startForeground()

Using a regular Service in foreground mode should work as long as you keep that service running on a separate process. For that, you need:

1. Make the onStartCommand() return START_STICKY.
2. Call the method to show the notification right in onCreate().
3. Run the service in a separate process (using android:process=":something").

Based on the post, it seems that you've tried some of these steps in isolation but never tried all of them at the same time.

If none of the answers above are working, maybe it is a manufacturer specific issue. Some MI phones, for instance, kill the foreground service when the user kill the app via task manager.

I recommend you to test the app on a virtual device, so you can check if it is or isn't this kind of issue.

Hope it helps!