a simple java time tips example

import java.awt.*;
import javax.swing.*;
public class TimerTest
{
	public static void main(String[] args)
	{
		mytask t=new mytask();
		while(true)
		{
			try
			{
				Thread.sleep(1800000);//time
				t.run();
			}catch(Exception e)
			{
			}
		}
	}
}
class mytask 
{
	public void run()
	{
		try
		{
			javax.swing.JOptionPane.showMessageDialog(null,"It's time to relax!","tips",2);
		}catch(HeadlessException e)
		{
		}
	}
}