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Question

I have a problem with notifications in my app. I want to set multiple notifications for different hours of the day. For example, let's take 8, 12 and 23 o'clock. But only the one at 23 o'clock triggers every day. What's wrong with my code and will it work even if the app is killed? Here's the code that sets alarms in my activity

public void myAlarm(int hour, int minute) {

    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.HOUR_OF_DAY, hour);
    calendar.set(Calendar.MINUTE, minute);
    calendar.set(Calendar.SECOND, 0);


    Intent intent = new Intent(getApplicationContext(), Reminder.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
    AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);

    if (alarmManager != null) {
        alarmManager.setInexactRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), AlarmManager.INTERVAL_DAY, pendingIntent);
    }
}

and this is what I wrote in onCreate

        myAlarm(8, 0);
        myAlarm(12, 0);
        myAlarm(23, 0);

this is my receiver

public class Reminder extends BroadcastReceiver {


@Override
public void onReceive(Context context, Intent intent) {
    Intent in = new Intent(context, MySecoundActivity.class);
    in.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

    PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, in, PendingIntent.FLAG_UPDATE_CURRENT);

    NotificationCompat.Builder builder = new NotificationCompat.Builder(context, "Reminder")
            .setSmallIcon(R.drawable.bell)
            .setContentTitle("Notification!")
            .setContentText("Text of notification")
            .setColor(0xfb3ff)
            .setAutoCancel(true)
            .setContentIntent(pendingIntent)
            .setPriority(NotificationCompat.PRIORITY_HIGH);


    NotificationManagerCompat notificationMngr = NotificationManagerCompat.from(context);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        CharSequence name = "Reminder";
        String description = "reminder channel";
        int importance = NotificationManager.IMPORTANCE_HIGH;
        NotificationChannel channel = new NotificationChannel("Reminder", name, importance);
        channel.setDescription(description);
        NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.createNotificationChannel(channel);

    }
    notificationMngr.notify(200, builder.build());
}

Receiver is in android manifest

<receiver android:name=".Reminder"/>

Answer 1

This is the expected behavior since in your code, when you set the alarm, you have to give every PendingIntent unique requestCode which in your case remains the same, ie, 0. So when you set another alarm with same requestCode, the last alarm gets updated to the new time instead of creating a new alarm. So only your last alarm works. So at the time of setting the alarm, in your PendingIntent.getBroadcast() , instead of the 0, you could use either the Random class to generate a random number every time or you could just use (int)System.currentTimeMillis() which would always be a different number.