How to configure notification channels to show multiple notifications

Question

I've written the code for two notification channels. But one notification triggers the other one so both of the notifications are shown. I've already tried FLAG_ONE_SHOT for pendingIntent but it's the same.

NotificationHelper class:

public class NotificationHelper extends ContextWrapper {
    public static final String channel1ID = "channel1ID";
    public static final String channel1Name = "Add transactions reminder";
    public static final String channel2ID = "channel2ID";
    public static final String channel2Name = "Due and overdue bills";
    private NotificationManager mManager;

    public NotificationHelper(Context base) {
        super(base);
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O)
            createChannels();
    }

    @RequiresApi(api = Build.VERSION_CODES.O)
    public void createChannels() {
        NotificationChannel channel1 = new NotificationChannel(channel1ID, channel1Name, NotificationManager.IMPORTANCE_DEFAULT);
        channel1.enableLights(true);
        channel1.enableVibration(true);
        channel1.setLightColor(R.color.colorPrimary);
        channel1.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
        getManager().createNotificationChannel(channel1);

        NotificationChannel channel2 = new NotificationChannel(channel2ID, channel2Name, NotificationManager.IMPORTANCE_DEFAULT);
        channel2.enableLights(true);
        channel2.enableVibration(true);
        channel2.setLightColor(R.color.colorPrimary);
        channel2.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);
        getManager().createNotificationChannel(channel2);
    }

    public NotificationManager getManager() {
        if (mManager == null) {
            mManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        }
        return mManager;
    }

    public NotificationCompat.Builder getChannel1Notification(String title, String message) {
        Intent intent = new Intent(getApplicationContext(), MainActivity.class);
        int reqCode = (int) System.currentTimeMillis();
        PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), reqCode, intent, PendingIntent.FLAG_UPDATE_CURRENT);

        return new NotificationCompat.Builder(getApplicationContext(), channel1ID)
                .setContentTitle(title)
                .setContentText(message)
                .setSmallIcon(R.drawable.ic_notification_icon)
                .setAutoCancel(true)
                .setContentIntent(pendingIntent);
    }

    public NotificationCompat.Builder getChannel2Notification(String title, String message) {
        Intent intent = new Intent(getApplicationContext(), MainActivity.class);
        int reqCode = (int) System.currentTimeMillis();
        PendingIntent pendingIntent = PendingIntent.getActivity(getApplicationContext(), reqCode, intent, PendingIntent.FLAG_UPDATE_CURRENT);

        return new NotificationCompat.Builder(getApplicationContext(), channel2ID)
                .setContentTitle(title)
                .setContentText(message)
                .setSmallIcon(R.drawable.ic_notification_icon)
                .setAutoCancel(true)
                .setContentIntent(pendingIntent);
    }
}

AlertReceiver class:

public class AlertReceiver extends BroadcastReceiver {
    public static final String TAG = "AlertReceiver";
    @Override
    public void onReceive(Context context, Intent intent) {
        NotificationHelper notificationHelper = new NotificationHelper(context);

        //add transactions reminder
        NotificationCompat.Builder nb1 = notificationHelper.getChannel1Notification(
                notificationHelper.getString(R.string.trans_notify_title), notificationHelper.getString(R.string.notification_msg)
        );
        notificationHelper.getManager().notify(1, nb1.build());

        //due and overdue bills
        NotificationCompat.Builder nb2 = notificationHelper.getChannel2Notification(
                notificationHelper.getString(R.string.bills_notify_title), notificationHelper.getString(R.string.notification_msg)
        );
        notificationHelper.getManager().notify(2, nb2.build());
}
}

first notification:

public void startAlarm(Calendar c) {
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent(this, AlertReceiver.class);
        int reqCode = (int) System.currentTimeMillis();
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this, reqCode, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        alarmManager.setExact(AlarmManager.RTC_WAKEUP, c.getTimeInMillis(), pendingIntent);

        Toast.makeText(this, getString(R.string.notification_set_at) + timeString + getString(R.string.everydayy), Toast.LENGTH_LONG).show();
    }

second notification:

private void setNotifications(int dueDayOfYear) {
        LocalDate dueDate = LocalDate.ofYearDay(LocalDate.now().getYear(), dueDayOfYear);
        LocalDateTime prevDay = dueDate.minusDays(1).atStartOfDay().plusHours(14).plusMinutes(7);
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent(context, AlertReceiver.class);
        int reqCode = (int) System.currentTimeMillis();
        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, reqCode, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        alarmManager.setExact(AlarmManager.RTC_WAKEUP, prevDay.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli(), pendingIntent);
    }

(plusHours and plusMinutes are used to test and to make sure that the notifications are set at different times)

I think something's wrong with the AlertReceiver class but I can't figure it out. How do I fix this?

Answer 1

Found the problem. It's when calling notify() in the AlertReceiver class. I solved it by generating a unique id when calling it.

public void onReceive(Context context, Intent intent) {
        NotificationHelper notificationHelper = new NotificationHelper(context);
        int id = (int) System.currentTimeMillis(); //this is the fix

        //add transactions reminder
        NotificationCompat.Builder nb1 = notificationHelper.getChannel1Notification(
                notificationHelper.getString(R.string.trans_notify_title), notificationHelper.getString(R.string.notification_msg)
        );
        notificationHelper.getManager().notify(id, nb1.build());

        //due and overdue bills
        NotificationCompat.Builder nb2 = notificationHelper.getChannel2Notification(
                notificationHelper.getString(R.string.bills_notify_title), notificationHelper.getString(R.string.notification_msg)
        );
        notificationHelper.getManager().notify(id, nb2.build());