通过继承 JPanel 类和实现 Runnable 类，重写 paint(Graphics g) 和 run() 方法

来完成动态功能的：

class DrawPanel extends JPanel implements Runnable{    public void paint(Graphics g) {                super.paint(g);        //ToDo        }    public void run(){                while(true){                this.repaint();        }    }    }

直接实例化使用：

Container ct = this.getContentPane();    DrawPanel dp = new DrawPanel();    ct.add(dp);            Thread t = new Thread(dp);    t.start();