Countdown.sh

#!/home/adrian/java/openjdk-11/bin/java --source 11

//Simple CRON Job reimplemented using Java APIs!

import java.io.File;
import java.util.Date;
import java.util.Timer;
import java.util.Calendar;
import java.util.TimerTask;
import java.time.LocalDateTime;

public class Countdown {

	private static class DeleteClassFiles extends TimerTask {
		public void run () {
			System.out.println(".....running imitation CRON JOB......");

			try {
				//CRON JOB - Create File
				if (new File("JavaIsTheBest.blah").isFile())
					System.out.println("File already exists.");
				else
					if (new File("JavaIsTheBest.blah").createNewFile())
						System.out.println("File successfully created.");
					else 
						System.out.println("File was not successfully created");
			} catch (java.io.IOException ioe) { };
			
			System.out.println("Ending countdown for task......" + LocalDateTime.now());
			System.exit(0);
		}
	}

	public static void main (String[] args) {

		//It's a shame that Timer/TimerTask doesn't work with the Java8 DateTime APIs!
		try {
			//Grab Time, Add Time
			var dt = Calendar.getInstance();
			dt.setTime(new Date());
			dt.add(Calendar.SECOND, Integer.valueOf(args[0]));

			//Schedule job
			var timer = new Timer();
			System.out.println("Beginning countdown for task......" + LocalDateTime.now());
			timer.schedule(new Countdown.DeleteClassFiles(), dt.getTime());
		} catch (NumberFormatException nfe) { System.out.println("Malformed input."); };

	}
}