How To give notifications on android on specific time?

Question

I want to give notification to my app on a specific time. Say everyday i have to give notification on 7 AM even if the app is closed.

How can i do this? Any tutorial

Answer 1

You can use AlarmManager to set alarm at specified time

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
if (!prefs.getBoolean("firstTime", false)) {

    Intent alarmIntent = new Intent(this, AlarmReceiver.class);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, alarmIntent, 0);

    AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

    Calendar calendar = Calendar.getInstance();
    calendar.setTimeInMillis(System.currentTimeMillis());
    calendar.set(Calendar.HOUR_OF_DAY, 7);
    calendar.set(Calendar.MINUTE, 0);
    calendar.set(Calendar.SECOND, 1);

    manager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
            AlarmManager.INTERVAL_DAY, pendingIntent);

    SharedPreferences.Editor editor = prefs.edit();
    editor.putBoolean("firstTime", true);
    editor.apply();
}

I used SharedPreferences to check that's not the first time to run the app and if it is, you set that alarm otherwise do nothing instead of resetting the alarm each time you start your app.
Use a BroadcastReceiver to listen when the alarm happens

public class AlarmReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        // show toast
        Toast.makeText(context, "Alarm running", Toast.LENGTH_SHORT).show();
    }
}

Use another receiver to listen to device boots so that you can reset the alarm

public class DeviceBootReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals("android.intent.action.BOOT_COMPLETED")) {
            // on device boot compelete, reset the alarm
            Intent alarmIntent = new Intent(context, AlarmReceiver.class);
            PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, alarmIntent, 0);

            AlarmManager manager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);

            Calendar calendar = Calendar.getInstance();
            calendar.setTimeInMillis(System.currentTimeMillis());
            calendar.set(Calendar.HOUR_OF_DAY, 7);
            calendar.set(Calendar.MINUTE, 0);
            calendar.set(Calendar.SECOND, 1);

            manager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(),
                    AlarmManager.INTERVAL_DAY, pendingIntent);
        }
    }
}

add the permission to the manifest

then register your receivers