Duvida com JProgressBar

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class Teste extends JFrame 
{
	private Timer timer;
	private int cont=0;
	private JProgressBar jp;

	public Teste()
	{
		super("Teste");
		Container p=new Container();
		p=getContentPane();
		p.setLayout(null);
		setBounds(250,200,300,200);
		
		jp=new JProgressBar(JProgressBar.HORIZONTAL,0,20);
		jp.setValue(cont);
		jp.setBounds(15,50,250,10);
		p.add(jp);
		timer = new Timer(1 * 200, new ActionListener() {
			public void actionPerformed(ActionEvent ev) {
				jp.setValue(cont++);
				jp.updateUI();
			
				if(jp.getValue()==20)
				{
					timer.stop();
					setVisible(false);
				}
			}
		});
      	timer.start(); 
      	setVisible(true);       
	}
    public static void main(String[] args) 
    {
        new Teste();
   } 
}