AlarmManager doesn't fire

Question

my note app should remember my users with a notification at their note at a specific date and time the user had set. My Problem is that I don't get the notification at the set time.
This is my alarmManager.class (Here I create my Alarms)

public class alarmManager {

    public static void createAlarm(long timeInMillis, int requestCode, Intent i) {
        PendingIntent pi = PendingIntent.getService(MainActivity.context, requestCode, i, PendingIntent.FLAG_UPDATE_CURRENT);
        getAlarmManager().set(AlarmManager.RTC_WAKEUP, timeInMillis, pi);
    }

    public static void deleteAlarm(Intent i, int requestCode) {
        if (doesPendingIntentExist(MainActivity.context, i, requestCode)) {
            PendingIntent pi = PendingIntent.getService(MainActivity.context, requestCode, i, PendingIntent.FLAG_NO_CREATE);
            pi.cancel();
            getAlarmManager().cancel(pi);
        }
    }

    private static AlarmManager getAlarmManager() {
        return (AlarmManager) MainActivity.context.getSystemService(Context.ALARM_SERVICE);
    }

    private static boolean doesPendingIntentExist(Context context, Intent i, int requestCode) {
        PendingIntent pi = PendingIntent.getService(context, requestCode, i, PendingIntent.FLAG_NO_CREATE);
        return pi != null;
    }
}  

When the user creates a new note this lines get fired (They send everything is needed to my alarmManager.class)

Intent i = new Intent(MainActivity.context, NotificationService.class);
        i.putExtra(NotificationService.i_UID, id);
        i.putExtra(NotificationService.i_TEXT, title);
        i.putExtra(NotificationService.i_CONTENT, content);
        i.putExtra(NotificationService.i_REMINDEDATE, mUserReminderDate);
        i.putExtra(NotificationService.i_REPEAT, repeatAlarmSelectedOption);
        alarmManager.createAlarm(mUserReminderDate.getTime(), id.hashCode(), i);  

When everything works the NotificationService.class should get called at the chosen time. (Here the notification should show to the user)

public class NotificationService extends IntentService {
    public static final String i_UID = "uuid";
    public static final String i_TEXT = "title";
    public static final String i_CONTENT  = "content";
    public static final String i_REMINDEDATE = "remindeDate";
    public static final String i_REPEAT = "repeatAlarm";

    private String mTodoText, mTodoContent, mTodoUUID;
    private Date mTodoDate;
    private int mTodoRepeat;
    private Intent processIntent;

    public NotificationService() {
        super("NotificationService");
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        this.processIntent = intent;
        mTodoText = intent.getStringExtra(i_TEXT);
        mTodoContent = intent.getStringExtra(i_CONTENT);
        mTodoUUID = intent.getStringExtra(i_UID);
        mTodoDate = (Date) intent.getSerializableExtra(i_REMINDEDATE);
        mTodoRepeat = intent.getIntExtra(i_REPEAT, 0);

        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        Notification notification = new Notification.Builder(this)
                .setContentTitle(mTodoText)
                .setContentText(mTodoContent)
                .setSmallIcon(R.drawable.app_logo_transparent_bg)
                .setAutoCancel(true)
                .setDefaults(Notification.DEFAULT_SOUND)
                .build();

        manager.notify(100, notification);
    }  

Unfortunately it doesn't work. No errors. No notification. Nothing.
I hope someone can help me.

Answer 1

In my opinion the problem is when you create a PendingIntent :

PendingIntent pi = PendingIntent.getService(MainActivity.context, requestCode, i, PendingIntent.FLAG_UPDATE_CURRENT);

To be absolutely sure, schedule an alarm, then run from adb following command: adb shell dumpsys alarm and search for your PendingIntent . If you find it, schedule one more time alarm and run command one more time. Look again for your pending intent and make sure it is a new one and try to search for this previous scheduled. If it is problem with PendingIntent you will find only the newest PendingIntent .

Solution:
Since AlarmManger while comparing PendingIntents doesn't compare extra data passed it, but compares request code, data, action and categories you need to change one of them every time you schedule a new alarm. My suggestion is to pass uri from database to every new scheduled PendingIntent . That will make each of them uniqal so the older one won't be cancelled when a new scheduled. To sum up, to argument i in your code call method setData() and pass uri as an argument. You can do it in a method or from a class where method is being called. It may look like that:

 public static void createAlarm(long timeInMillis, int requestCode, Intent i, Uri uri) {
       i.setData(uri)
        PendingIntent pi = PendingIntent.getService(MainActivity.context, requestCode, i, PendingIntent.FLAG_UPDATE_CURRENT);
        getAlarmManager().set(AlarmManager.RTC_WAKEUP, timeInMillis, pi);
    }