小游戏桌游制作，双缓存

import java.awt.*;

import javax.swing.*;

public class BallGame extends JFrame{
Image ball=Toolkit.getDefaultToolkit().getImage(“images/ball.png”);
Image desk=Toolkit.getDefaultToolkit().getImage(“images/desk.jpg”);
double x=100;
double y=100;
boolean right=true;
private Image OffScreenImage=null;
public void paint(Graphics g){
if(OffScreenImage==null){
OffScreenImage=this.createImage(856,500);
}
Graphics goff=OffScreenImage.getGraphics();

	goff.drawImage(desk,0,0,null);goff.drawImage(ball,(int)x,(int)y,null);if(right){x=x+10;}else{x=x-10;}if(x>856-40-30){right=false;}if(x<40){right=true;}g.drawImage(OffScreenImage,0,0, null);
}void launchFrame(){	setSize(856,500);setLocation(50,50);setVisible(true);while(true){repaint();try {Thread.sleep(40);} catch (InterruptedException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}public static void main(String[] args ){System.out.println("JOJO的桌游");BallGame game=new BallGame();game.launchFrame();} 

}