Java多线程-两个小球

 1 import java.applet.*;
 2 import java.awt.*;
 3 import javax.swing.*;
 4 
 5 public class MyBall {
 6     public static void main(String[] args) {
 7         JFrame w = new JFrame();
 8         w.setSize(300, 400);
 9         MyPanel mp = new MyPanel();
10         w.add(mp);
11         Thread b1 = new Thread(mp, "b1");
12         Thread b2 = new Thread(mp, "b2");
13         b1.start();
14         b2.start();
15         w.show();
16     }
17 }
18 
19 class MyPanel extends JPanel implements Runnable {
20     int gx = 40, gy = 30, tx = 60, ty = 30;
21     String str1 = "b1", str2 = "b2";
22 
23     public void run() {
24         boolean stop = false;
25         while (!stop) {
26             String s = Thread.currentThread().getName().toString();
27             if (s.equals(str1)) {
28                 gy++;
29                 try {
30                     Thread.sleep(60);
31                 } catch (Exception e) {
32                 }
33                 if (gy >= 200)
34                     stop = true;
35             } else {
36                 ty++;
37                 try {
38                     Thread.sleep(30);
39                 } catch (Exception e) {
40                 }
41                 if (ty >= 200)
42                     stop = true;
43             }
44             repaint();
45         }
46     }
47 
48     public void paint(Graphics g) {
49         super.paint(g);
50         g.fillOval(gx, gy, 20, 20);
51         g.fillOval(tx, ty, 20, 20);
52     }
53 }