DoubleBufferin

package PingPong;

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


public class PingPong extends JFrame implements Runnable {

    private Ball ball = new Ball(100, 150, this);

    private Image dbImage;
    private Graphics dbg;

//-----------------------------------------------------------------

    public PingPong(String title) {
        super(title);
    }
//-----------------------------------------------------------------

    public void paint (Graphics graphics) {

        super.paint(graphics);

        graphics.drawImage(Toolkit.getDefaultToolkit().getImage("Bilder/Spielfeld.png"), 0, 0, this);

        ball.paint(graphics);
    }

//-----------------------------------------------------------------

    public  void update (Graphics graphics) {

        if ( dbImage == null) {

            dbImage = createImage (this.getSize().width,this.getSize().height);
            dbg = dbImage.getGraphics();
        }

        dbg.setColor(getBackground());
        dbg.fillRect (0, 0, this.getSize().width, this.getSize().height);

        dbg.setColor (getForeground());
        run ();

        graphics.drawImage (dbImage, 0, 0, this);

    }

//-----------------------------------------------------------------

    public void run() {

        Thread.currentThread().setPriority(Thread.MIN_PRIORITY);

        while(true) {

            ball.moveBall();

            update(getGraphics());

            try {

                Thread.sleep(20);

            } catch (InterruptedException ex) {


            }             //Wiederholt sich mit Pause: 20ms

            Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
        }
    }

//-----------------------------------------------------------------

    public static void main(String[] args) {
        PingPong pong = new PingPong("PingPong-Spiel");
        pong.setSize(800, 500);
        pong.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pong.setVisible(true);
        new Thread(pong).start();

    }
}