77_Timer Task

import java.util.Calendar;
import java.util.Timer;
import java.util.TimerTask;

//Timer = A facility for threads to schedule task for future execution in a background thread
//TimerTask = A task that can be scheduled for one-time or repeated execution by a Timer
public class Main{
    public static void main (String[] args){
        Timer timer = new Timer();
        TimerTask task = new TimerTask(){
            
            @Override
            public void run() {
                System.out.println("Task is  complete :)");

            }
        };

        /*Case 1*/
        //timer.schedule(task,0);//(task,time delay)
        // >> Task in complete :) shown after 0s


        Calendar date = Calendar.getInstance();
        date.set(Calendar.YEAR,2020);
        date.set(Calendar.MONTH,Calendar.JUNE);
        date.set(Calendar.DAY_OF_MONTH,20);
        date.set(Calendar.HOUR_OF_DAY,0);//0-24
        date.set(Calendar.MINUTE,0);
        date.set(Calendar.SECOND,0);
        date.set(Calendar.MILLISECOND,0);

        timer.schedule((task, date.getTime());
        //>>Shown at 20 June 2022 00:00
        
-------schedule.AtFixedRate
import java.util.Calendar;
import java.util.Timer;
import java.util.TimerTask;

//Timer = A facility for threads to schedule task for future execution in a background thread
//TimerTask = A task that can be scheduled for one-time or repeated execution by a Timer
public class Main{
    public static void main (String[] args){
        Timer timer = new Timer();
        TimerTask task = new TimerTask(){

            int counter = 10;
            @Override
            public void run() {
                if(counter>0) {
                    System.out.println(counter + " seconds");
                    counter --;
                }
                else{
                    System.out.println("HAPPY NEW YEAR!");
                    timer.cancel();
                }

            }
        };

        Calendar date = Calendar.getInstance();
        date.set(Calendar.YEAR,2020);
        date.set(Calendar.MONTH,Calendar.DECEMBER);
        date.set(Calendar.DAY_OF_MONTH,31);
        date.set(Calendar.HOUR_OF_DAY,23);//0-24
        date.set(Calendar.MINUTE,59);
        date.set(Calendar.SECOND,50);
        date.set(Calendar.MILLISECOND,0);

        /*Case 3
        timer.scheduleAtFixedRate(task,0,1000);//(task, firstTime [Time/delay of first instance], period [how often repeat])
        >>
10 seconds
9 seconds
8 seconds
7 seconds
6 seconds
5 seconds
4 seconds
3 seconds
2 seconds
1 seconds
HAPPY NEW YEAR!
         */

        //To execute at a specific date time
        timer.scheduleAtFixedRate(task,date.getTime(),1000);
        //>>Same result as Case 3, but occur at specific date time
    }
}