import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
/**
 * @(#)BallPanel.java
 *
 *
 * @author
 * @version 1.00 2011/5/11
 */


public class BallPanel extends JPanel implements MouseMotionListener {

	static int x = 10;
	static int y = 10;

    public BallPanel() {

    	setBackground(Color.black);

    	addMouseMotionListener(this);
    }

    public void paintComponent(Graphics g){

    	super.paintComponent(g);
    	g.setColor(Color.orange);

    	g.fillOval(x-10, y-10, 20, 20);
    }



     public void mouseDragged(MouseEvent event){
     	x = event.getX();
    	y = event.getY();

    	repaint();
     }

	 public void mouseMoved(MouseEvent event){
	 }
}


















import java.awt.*;
import javax.swing.*;
/**
 * @(#)MovingBall.java
 *
 * MovingBall application
 *
 * @author cemo
 * @version 1.00 2011/5/11
 */

public class MovingBall {

    public static void main(String[] args) {

    	JFrame frame = new JFrame("ayy");

    	BallPanel panel = new BallPanel();

    	frame.getContentPane().add(panel);


    	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    	frame.setBounds(200,200, 500, 500);
    	frame.setBackground(Color.white);
    	frame.setVisible(true);

    }
}