JAVA中解决双缓冲现象

代码如下：

import java.awt.*;import java.awt.event.*;public class TankClient extends Frame{    int x=50;    int y=50;    Image offScreenImage=null;    public void paint(Graphics g){        Color c=g.getColor();        g.setColor(Color.RED);        g.fillOval(x, y, 30, 30);//fillOval()方法中参数是int整形        g.setColor(c);        y+=5;    }    //解决双缓冲现象    public void update(Graphics g){        if(offScreenImage==null){            offScreenImage=this.createImage(800,600);        }        Graphics goffScreen=offScreenImage.getGraphics();        Color c=goffScreen.getColor();        goffScreen.setColor(Color.GREEN);        goffScreen.fillRect(0,0,800, 600);        goffScreen.setColor(c);        paint(goffScreen);        g.drawImage(offScreenImage, 0, 0, null);    }    public void LaunchFrame(){        this.setLocation(50,50);        this.setSize(800,600);        this.setTitle("TankWar");        this.addWindowListener(new WindowAdapter(){            @Override            public void windowClosing(WindowEvent e) {                System.exit(0);            }        });        this.setResizable(false);//窗口不可调节大小        this.setBackground(Color.GREEN);        this.setVisible(true);        new Thread(new paintThread()).start();    }    public static void main(String[] args) {        TankClient tk=new TankClient();        tk.LaunchFrame();    }    private class paintThread implements Runnable{        public void run(){            while(true){                repaint();//重量级中repaint首先调用update方法，update然后再调用paint方法。再轻量级组件中repaint直接调用paint方法                try {                    Thread.sleep(50);                } catch (InterruptedException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }            }        }    }}