Attaching listener to FirebaseDb in FirebaseJobDispatcher

Question

I am using Firebase Job Dispatcher to execute a periodic task that will execute every 15 mins and check for data in the firebase database and display a notification about the latest data.
The issue I am facing is that, the listener isn't getting attached properly in onStartJob, i.e. the logging statements inside onDataAdded is never called.
I've linked my code below,

public class FetchInfoService extends JobService {

InfoObject note;
NotificationCompat.Builder notificationBuilder;
private static final String TAG = "SyncService";

public FetchInfoService() {
}

@Override
public boolean onStartJob(com.firebase.jobdispatcher.JobParameters job) {
    Log.e(TAG, "Executing job id: " + job.getTag());
    DatabaseReference dbReference = FirebaseDatabase.getInstance().getReference().child(CONTENT);
    Log.e(TAG,dbReference.getKey());
    dbReference.addValueEventListener(new ValueEventListener() {

        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            Log.e(TAG,"OnDataChanged Called");    //----Never Called


            for (DataSnapshot infoDataSnapshot : dataSnapshot.getChildren()) {
                note = infoDataSnapshot.getValue(InfoObject.class);
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            Log.e(TAG,"Listener Cancelled");
        }
    });

notificationBuilder = new NotificationCompat.Builder(getApplicationContext())
                    .setSmallIcon(R.drawable.ic_delete_black_48dp)
                    .setContentTitle(note.getTitle())
                    .setContentText(note.getDescription());
    NotificationManager mNotificationManager =
            (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

    mNotificationManager.notify(1, notificationBuilder.build());
    return false;
}

@Override
public boolean onStopJob(com.firebase.jobdispatcher.JobParameters job) {
    Log.e(TAG, "Finished job: " + job.getTag());
    return false;
}

}

Thanks

Answer 1

Apparently the reason as to why the listener was never called was that my code kept throwing a null pointer exception where I was displaying the Notification and hence it never got to the point where I was attaching listener and listening for changes in the Database. Moving the code to display the notification inside onChildAdded fixed it for me.