Android background notifications with Firebase Cloud Messaging not received

Question

I\'ve searched a lot about notifications when the app is in the background or closed. I\'m using Firebase Cloud Messaging by the way. It won\'t work for me. I\'ve used the A

Answer 1

When the app is closed, it shutdowns the service. You must to restart the service.

On your Application class, implements ActivityLifecycleCallbacks and on onActivityDestroyed restart the service with an alarm.

public class YourApplication extends Application implements Application.ActivityLifecycleCallbacks {
    @Override
    public void onCreate() {
        super.onCreate();
        registerActivityLifecycleCallbacks(this);
    }

    @Override
    public void onActivityDestroyed(Activity activity) {
            Intent restartService = new Intent(getApplicationContext(), MyAppFirebaseMessagingService.class);
            PendingIntent pendingIntent = PendingIntent.getService(getApplicationContext(),1,restartService,PendingIntent.FLAG_ONE_SHOT);
            AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
            alarmManager.set(AlarmManager.ELAPSED_REALTIME,5000,pendingIntent);
    }
}