Send notification at certain time with calendar

Question

Hi currently I'm trying to setup a button inside of a my list adapter. The idea of the button is that it grabs a set of values from two edit texts one being hour and the other being minutes values, it then sets it to the calendar and the alarm. After the application reaches a specific time it should then send a notification to the user but currently it sends the notification as soon as the button is pressed instead of waiting for the desired time, can anyone spot my error?

convertView = LayoutInflater.from(getContext()).inflate(R.layout.custom_row_contact_number, null);


            alarmManager = (AlarmManager) convertView.getContext().getSystemService(Context.ALARM_SERVICE);

            myCalendar = Calendar.getInstance();

            year_x = myCalendar.get(Calendar.YEAR);
            month_x = myCalendar.get(Calendar.MONTH);
            day_x = myCalendar.get(Calendar.DAY_OF_MONTH);


            receiver = new Intent(convertView.getContext(), Alarm_Reciever.class);


            Button btnSendMessage = (Button)convertView.findViewById(R.id.btnSendMessage);
            btnSendMessage.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    int hourValue = Integer.valueOf(editHours.getText().toString());
                    int minutevalue = Integer.valueOf(editMinutes.getText().toString());

                    Log.i("hour", Integer.toString(hourValue));






                    myCalendar.set(Calendar.HOUR_OF_DAY,hourValue);
                    myCalendar.set(Calendar.MINUTE, minutevalue);



                    pendingIntent = PendingIntent.getBroadcast(v.getContext(), 0, receiver, PendingIntent.FLAG_UPDATE_CURRENT);

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


                }
            });

        }

In addition if I move the below code to oncreate

        alarmManager = (AlarmManager) convertView.getContext().getSystemService(Context.ALARM_SERVICE);

        myCalendar = Calendar.getInstance();

        year_x = myCalendar.get(Calendar.YEAR);
        month_x = myCalendar.get(Calendar.MONTH);
        day_x = myCalendar.get(Calendar.DAY_OF_MONTH);


        receiver = new Intent(convertView.getContext(), Alarm_Reciever.class);

I'm left with the below code but I receive an error

java.lang.NullPointerException: Attempt to invoke virtual method 'void java.util.Calendar.set(int, int)' on a null object reference

  Button btnSendMessage = (Button)convertView.findViewById(R.id.btnSendMessage);
        btnSendMessage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                int hourValue = Integer.valueOf(editHours.getText().toString());
                int minutevalue = Integer.valueOf(editMinutes.getText().toString());

                Log.i("hour", Integer.toString(hourValue));






                myCalendar.set(Calendar.HOUR_OF_DAY,hourValue);
                myCalendar.set(Calendar.MINUTE, minutevalue);



                pendingIntent = PendingIntent.getBroadcast(v.getContext(), 0, receiver, PendingIntent.FLAG_UPDATE_CURRENT);

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


            }
        });

Answer 1

It could be because the day is always today, so the scheduled time might be in the past.

This can be solved in a few ways, but an easy one is to add this after you set the hours and minutes.

if(calendar.getTimeInMillis() < System.currentTimeMillis()) {
    calendar.add(Calendar.DAY_OF_YEAR, 1);
}