Stop Notification from being destroyed when the app closes

I am making a android app which will allow the user to press a button and show a notification with a timer counting down for a certain amount of time. Although I have made the notification persistent so it cannot be dismissed, when the app closes the notification gets destroyed.

Is there any way to allow a notification to continue running once the app is closed and not get destroyed.

Here is the code for starting my notification and timer:

final NotificationCompat.Builder builder = new NotificationCompat.Builder(context, "notifyLemubit")
.setSmallIcon(holder.img_timer.getImageAlpha())
.setContentTitle("Timer Running")
.setContentText("Time Until Your " + timer.getTimer_name() + " Tree has Fully Grown: " + timer.getTimer_duration_s())
.setOngoing(true)
.setPriority(NotificationCompat.PRIORITY_DEFAULT);
final NotificationManagerCompat notificationManagerCompat = NotificationManagerCompat.from(context);
notificationManagerCompat.notify(timer.getTimer_id(), builder.build());
new CountDownTimer(10 * ONE_SECOND, ONE_SECOND) {
@Override
public void onTick(long ms_until_done) {
builder.setContentText("Time Until Your " + timer.getTimer_name() + " Tree has Fully Grown: " + ms_until_done / ONE_SECOND);
notificationManagerCompat.notify(timer.getTimer_id(), builder.build());
}
@Override
public void onFinish() {
notificationManagerCompat.cancel(timer.getTimer_id());
final NotificationCompat.Builder builder = new NotificationCompat.Builder(context, "notifyLemubit")
.setSmallIcon(holder.img_timer.getImageAlpha())
.setContentTitle("Timer Finished")
.setContentText("Your " + timer.getTimer_name() + " is Fully Grown!")
.setPriority(NotificationCompat.PRIORITY_DEFAULT);
final NotificationManagerCompat notificationManagerCompat = NotificationManagerCompat.from(context);
notificationManagerCompat.notify(timer.getTimer_id(), builder.build());
}
}.start();

Any help is appreciated, Thanks

The only way by far i know is using a Foreground service by extending the Service or IntentService class

And inside your activity or adapter use this to start the service

context.startService(Intent(context,PersistentNotificationService.class))

For the service here use this one

public class PersistentNotificationService extends Service {
private final static int ONE_SECOND = 1000;
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
final NotificationCompat.Builder builder = new NotificationCompat.Builder(this, "notifyLemubit")
.setSmallIcon(R.drawable.img_timer)
.setContentTitle("Timer Running")
.setContentText("Your title goes here")
.setOngoing(true)
.setPriority(NotificationCompat.PRIORITY_DEFAULT);
new CountDownTimer(10 * ONE_SECOND, ONE_SECOND) {
@Override
public void onTick(long ms_until_done) {
// Whatever code you want here
}
@Override
public void onFinish() {
// To cancel , just close the service
stopForeground(true);
stopSelf();
}
}.start();
startForeground(2342, builder.build());
return START_STICKY;
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
}