simple animation in java

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

public class SimpleAnimation {
int x = 70;
int y = 70;

public static void main(String[] args)
{
SimpleAnimation gui = new SimpleAnimation () ;
gui.go();
}

public void go()
{
JFrame frame = new JFrame() ;
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

MyDrawPanel drawPanel = new MyDrawPanel() ;

frame.getContentPane().add(drawPanel);
frame.setSize(300,300);
frame.setVisible(true);

for(int i=0;i<=130;i++)
{
x++ ;
y++ ;
drawPanel.repaint();

try
{
Thread.sleep(50);
}
catch(Exception ex) { }
}
}

class MyDrawPanel extends JPanel {

public void paintComponent(Graphics g)
{
g.setColor(Color.green);
g.fillOval(x,y,40,40);
}
}
}