MyAlarm.java

public class MyAlarm extends BroadcastReceiver {

    private NotificationManager alarmNotificationManager;
    String NOTIFICATION_CHANNEL_ID = "channel_id";
    String NOTIFICATION_CHANNEL_NAME = "nama channel";


    @Override
    public void onReceive(final Context context, Intent intent) {
	
        // menjalankan audio
        MediaPlayer mediaPlayer = MediaPlayer.create(context, R.raw.adzan);
        mediaPlayer.start();

        sendNotification(context, intent);

    }

    private void sendNotification(Context context, Intent itn) {
	
        String notif_title = itn.getExtras().getString("title");
        String notif_message = itn.getExtras().getString("message");
		
        alarmNotificationManager = (NotificationManager) context
                .getSystemService(Context.NOTIFICATION_SERVICE);
				
        Intent newIntent = new Intent(context, LoadActivity.class);
        newIntent.putExtra("notifkey", "notifvalue");
        PendingIntent contentIntent = PendingIntent.getActivity(context, 0,
                newIntent, PendingIntent.FLAG_UPDATE_CURRENT);

        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            int importance = NotificationManager.IMPORTANCE_HIGH;
            NotificationChannel mChannel = new NotificationChannel(
                    NOTIFICATION_CHANNEL_ID, NOTIFICATION_CHANNEL_NAME, importance);
            alarmNotificationManager.createNotificationChannel(mChannel);
        }

        NotificationCompat.Builder alamNotificationBuilder = new NotificationCompat.Builder(context, NOTIFICATION_CHANNEL_ID);
        alamNotificationBuilder.setContentTitle(notif_title);
        alamNotificationBuilder.setContentText(notif_message);
        alamNotificationBuilder.setSmallIcon(R.mipmap.ic_launcher);
        alamNotificationBuilder.setAutoCancel(true);
        alamNotificationBuilder.setContentIntent(contentIntent);

        alarmNotificationManager.notify(itn.getExtras().getInt("id"), alamNotificationBuilder.build());
		
    }

}