A New Thread With Each Mouse Click

Question

Dear Java Programmers,
The following code gives a bouncing ball inside of a panel. With each click, I need to have a different ball added and the previous ball to keep on bouncing. This part is a larger question of multitreading. When I have an action listener for mouse clicks, and I need to have a new thread with each click, how do I do this and where do I put it?
Thank you in advance.
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.*;
import java.awt.Color;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
public class Multiball extends JPanel implements Runnable, MouseListener {
Thread blueBall;
boolean xUp, yUp;
int x= -10, y= -10, xDx, yDy;
public Multiball()
xUp = false;
yUp = false;
xDx = 1;
yDy = 1;
addMouseListener( this );
public void mousePressed( MouseEvent e )
x = e.getX();
y = e.getY();
blueBall = new Thread( this );
blueBall.start();
public void paint( Graphics g )
super.paint( g );
g.setColor( Color.blue );
g.fillOval( x, y, 10, 10 );
public void run()
while ( true ) {
try {
blueBall.sleep( 10 );
catch ( Exception e ) {
System.err.println( "Exception: " + e.toString() );
if ( xUp == true )
x += xDx;
else
x -= xDx;
if ( yUp == true )
y += yDy;
else
y -= yDy;
if ( y <= 0 ) {
yUp = true;
yDy = ( int ) ( Math.random() * 1 + 2 );
else if ( y >= 183 ) {
yDy = ( int ) ( Math.random() * 1 + 2 );
yUp = false;
if ( x <= 0 ) {
xUp = true;
xDx = ( int ) ( Math.random() * 1 + 2 );
else if ( x >= 220 ) {
xUp = false;
xDx = ( int ) ( Math.random() * 1 + 2 );
repaint();
public void mouseExited( MouseEvent e ) {}
public void mouseClicked( MouseEvent e ) {}
public void mouseReleased( MouseEvent e ) {}
public void mouseEntered( MouseEvent e ) {}
public static void main(String args[])
JFrame a = new JFrame("Ball Bounce");
a.add(new Multiball(), BorderLayout.CENTER);
a.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
a.setSize(240,230);
a.setVisible(true);
}

Answer 1

Thank you very much for your replies. As for the multithreading, I have created 20 threads in the main method. With each click, one of these 20 threads starts in order. Now, how do I get a ball to paint with each one? How do I reference them in the paintComponent method?
   public void mousePressed( MouseEvent e )
         x = e.getX();
         y = e.getY();
         blueBall = new Thread( this );
         blueBall.start();
         count ++;
         System.out.print ("count is " + count);
      MyThread[] threads = new MyThread[20];
            for ( int ball = 0;ball < count; ball ++){
            threads[ball] = new MyThread ("" + ball);
            threads[ball].start ();
   }