Android AlarmManager only sending last scheduled notification

Question

I am creating a research app that should prompt the user 4 times a day to enter their mood - by sending a notification, which when clicked launches the correct Activity. I am able to schedule these notifications using AlarmManager, however only the last scheduled notification ever shows. So although I schedule them for 9AM, 2PM, 5PM, and 8PM, it only ever sends a notification at 8PM.

How can I get all of the scheduled notifications to show?

Here is my code for setting (one of) the alarms (from a notification manager class). Note that al alarms are set using the same instance of AlarmManager:

        cal.setTimeInMillis(System.currentTimeMillis());
        cal.set(Calendar.HOUR_OF_DAY, 9);
        cal.set(Calendar.MINUTE, 0);
        AlarmManager am = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        am.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), createPendingIntent(9, this)); 

Here is the createPendingIntent method (in the same notification manager class):

public static PendingIntent createPendingIntent(int hour, Context c){
        Intent notificationIntent = new Intent(c, AlarmBroadcastReceiver.class);
        notificationIntent.putExtra("time", hour);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(c, 0 , notificationIntent , PendingIntent.FLAG_UPDATE_CURRENT);
        return pendingIntent;
    }

Here is the BroadcastReceiver for the alarm:

public class AlarmBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        NotificationSender.createNotification(context);
    }
}

And finally the createNotification method:

public static void createNotification(Context c){
        Log.e("notif?", "creating");
        Intent intent = new Intent(c, UpdateMoodActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        int notificationId = new Random().nextInt();
        PendingIntent pendingIntent = PendingIntent.getActivity(c, 0, intent, 0);

        NotificationCompat.Builder builder = new NotificationCompat.Builder(c, "com.lizfltn.phdapp.notifChannelID")
                .setSmallIcon(R.drawable.ic_launcher_foreground)
                .setContentTitle("SoftMood")
                .setContentText("Please record your mood")
                .setPriority(NotificationCompat.PRIORITY_HIGH)
                .setContentIntent(pendingIntent)
                .setAutoCancel(true);

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(c);
        notificationManager.notify(notificationId, builder.build());
    }

Yes I know this isn't the best-practice way of doing things, or even the neatest, but unfortunately I need to get code working ahead of writing good code :P

I've tried various configurations of setting the alarm, e.g. using elapsed realtime instead of RTC, only setting the alarm, setting the exact alarm, etc, but there might be something fundamental I'm not understanding about how those work.

Any help appreciated!

Answer 1

Can you try with same id in pending intent and notify.? Notification id in createNotification() method is random id.

int notificationId = new Random().nextInt();

and id used in createPendingIntent method is 0.

 PendingIntent pendingIntent = PendingIntent.getBroadcast(c, 0 , notificationIntent , PendingIntent.FLAG_UPDATE_CURRENT);

Can you try with using same value for second parameter of getBroadcast?