Alarm Notification fires instantly. Android

Question

I am working on a Reminder that sends notification on fixed time to the user.

The alarm is getting off instantly ...

I tried most of the suggestions over s

Answer 1

Finally I found a way to do that by storing PendingIntent requestCode in database (used ROOM) , then cancelling all the alarm by retrieving all the requestCode from DB

AlarmIdPojo

@Entity
public class AlarmIdPojo {

    @PrimaryKey(autoGenerate = true)
    public int id;

    private int requestCode;

    public AlarmIdPojo() {
    }

    public int getRequestCode() {
        return requestCode;
    }

    public void setRequestCode(int requestCode) {
        this.requestCode = requestCode;
    }
}

AlarmIdDAO

@Dao
public interface AlarmIdDAO {

    @Query("select * from AlarmIdPojo")
    List getAllRequestCode();

    @Query("delete from AlarmIdPojo")
    public void deleteAllRequestCode();

    @Insert(onConflict = REPLACE)
    void addRequestCode(AlarmIdPojo pojo);
}

AppDatabase

@Database(entities = {AlarmIdPojo.class}, version = 1)
public abstract class AppDatabase extends RoomDatabase {

    public abstract AlarmIdDAO requestIdPojo();

    @Override
    protected SupportSQLiteOpenHelper createOpenHelper(DatabaseConfiguration config) {
        return null;
    }

    @Override
    protected InvalidationTracker createInvalidationTracker() {
        return null;
    }
}

callReminder

private void callReminder() {


        //  java.lang.IllegalStateException: Cannot access database on the main thread since it may potentially lock the UI for a long period of time.
        // because of this Exception , we are doing this in AsyncTask

        new AsyncTask() {
            @Override
            protected Void doInBackground(Void... voids) {
                List idList = appDatabase.requestIdPojo().getAllRequestCode();

                Intent notifyIntent = new Intent(MainActivity.this, MyReceiver.class);
                AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
                PendingIntent pendingIntent;

                for (int i = 0; i < idList.size(); i++) {


                    int requestId = idList.get(i).getRequestCode();

                    pendingIntent = PendingIntent.getBroadcast(MainActivity.this, requestId, notifyIntent, PendingIntent.FLAG_UPDATE_CURRENT);

                    // Cancel alarms
                    try {
                        alarmManager.cancel(pendingIntent);
                    } catch (Exception e) {
                        Log.e(TAG, "AlarmManager update was not canceled. " + e.toString());
                    }

                }

                appDatabase.requestIdPojo().deleteAllRequestCode();
                return null;
            }

            @Override
            protected void onPostExecute(Void aVoid) {
                super.onPostExecute(aVoid);

                // Once every request code is deleted , then once again call setReminderNotification() for fresh data.
                setReminderNotification();

            }
        }.execute();


    }

setReminderNotification

private void setReminderNotification() {

        Intent notifyIntent = new Intent(this, MyReceiver.class);
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        PendingIntent pendingIntent;


        // Taking existing offline reminder data from sharePreference
        Type type = new TypeToken>() {
        }.getType();
        List reminderList = new Gson().fromJson(sharedPrefUtils.getString(sharedPrefUtils.DEFAULT_REMINDERS), type);


        for (int i = 0; i < reminderList.size(); i++) {

            String time = reminderList.get(i).getTime();

            String strSpit[] = time.split(":");

            String strDays[] = reminderList.get(i).getDays().split(",");


            Calendar todayWithTime = Calendar.getInstance();
            todayWithTime.set(Calendar.SECOND, 0);
            todayWithTime.set(Calendar.MILLISECOND, 0);


            for (int j = 0; j < strDays.length; j++) {

                Calendar alarm = Calendar.getInstance();
                alarm.set(Calendar.SECOND, 0);
                alarm.set(Calendar.MILLISECOND, 0);

                alarm.set(Calendar.HOUR_OF_DAY, Integer.parseInt(strSpit[0]));
                alarm.set(Calendar.MINUTE, Integer.parseInt(strSpit[1]));
                alarm.set(Calendar.DAY_OF_WEEK, viewFunctions.getDayInt(strDays[j]));


                int randomPendingIntentId = generateRandomId();
                notifyIntent.putExtra(Constants.REMINDER_NAME, reminderList.get(i).getName());
                notifyIntent.putExtra(Constants.ID, randomPendingIntentId); // passing it , so that we can cancel this PendingIntent with this Id, once notification is shown.This is done to prevent past time alarm firing
                notifyIntent.putExtra(Constants.REMINDER_DAY, viewFunctions.getDayInt(strDays[j]));
                pendingIntent = PendingIntent.getBroadcast(this, randomPendingIntentId, notifyIntent, PendingIntent.FLAG_UPDATE_CURRENT);

                if (alarm.before(todayWithTime)) {
                    alarm.add(Calendar.DATE, 7);
                }

                alarmManager.set(AlarmManager.RTC_WAKEUP, alarm.getTimeInMillis(), pendingIntent);

                insertToDB(randomPendingIntentId);

            }
        }

    }

insertToDB

// Saving to DB. keeping track  of PendingIntent unique id.
    private void insertToDB(int randomPendingIntentId) {
        alarmIdPojo = new AlarmIdPojo();
        alarmIdPojo.setRequestCode(randomPendingIntentId);

        //  java.lang.IllegalStateException: Cannot access database on the main thread since it may potentially lock the UI for a long period of time.
        // because of this Exception , we are doing this in AsyncTask

        new AsyncTask() {
            @Override
            protected Void doInBackground(Void... voids) {
                appDatabase.requestIdPojo().addRequestCode(alarmIdPojo);
                return null;
            }
        }.execute();

    }