How to set alarm for every 10 minutes in Android Application in 9 and 12?

Question

I would like to set a repeating alarm, in android 8 or 9 it works. The question is how to set it to work it in 12 working parallel with android 8?

This is in the main activity, I set a startAlarm, and there is the missing part how to set the alarm in the case of sdk >= 31. When I start android to test it sends a notification at the beginning of the application but it do not send notification later.

MainActivity.java:

 private void startAlarm(long when) {
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            if (alarmManager.canScheduleExactAlarms()) {
                Log.e(TAG, "startAlarm: canScheduleExactAlarms");
            }
        }

        Intent intent = new Intent(this, AlarmReceiver.class);

        PendingIntent pendingIntent;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 1, intent,
                    PendingIntent.FLAG_IMMUTABLE | PendingIntent.FLAG_UPDATE_CURRENT);
        } else {
            pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 1, intent, 0);
        }


        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
            alarmManager.setExactAndAllowWhileIdle(
                    AlarmManager.RTC_WAKEUP,
                    when*1000,
                    pendingIntent
            );
        } else {
            alarmManager.setExact(
                    AlarmManager.RTC_WAKEUP,
                    when*1000,
                    pendingIntent
            );


        }
    }

I set AlarmReceiver to send notification. AlarmReceiver:

public class AlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        NotificationHelper notificationHelper = new NotificationHelper(context);
        NotificationCompat.Builder nb = notificationHelper.getChannelNotification();
        notificationHelper.getManager().notify(1, nb.build());
        long timeInSec = System.currentTimeMillis() / 1000;
        Settings.setLastNotificationSent(timeInSec, context);
    }
}

I set the permission in the manifest. AndroidManifest:

<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>
<uses-permission android:name="android.permission.SCHEDULE_EXACT_ALARM"/>

 <receiver android:name=".receiver.AlarmReceiver"
            android:exported="true"
            android:enabled="true">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
            </intent-filter>
        </receiver>

Answer 1

Probably you have to cancel previous alarm when you receive message in AlarmReceiver. I had the same problem and if i receive message from previous alarm i cancel it and then i can create new one.

private void cancelAlarm(){  
        Intent intent = new Intent(this, AlarmReceiver.class);    
        PendingIntent pendingIntent;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
            pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 1, intent,
                    PendingIntent.FLAG_IMMUTABLE | PendingIntent.FLAG_UPDATE_CURRENT);
        } else {
            pendingIntent = PendingIntent.getBroadcast(MainActivity.this, 1, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        }
        AlarmManager alarm = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
        alarm.cancel(pintent);
        pintent.cancel();
   }