java WHILE 循环问题

有没有办法让循环在5秒以后自动退出？

我觉得不应该在while里面改，还是应该针对receive方法进行修改，应该可以设置timeout的。

利用线程就可以啊

可以用计时器啊，看看java.util.timer的schedule方法，或许可以解决问题

用JAVA实现多线程编写,使得许多小球在界面内循环跳动

下面这段代码应该符合你的需求 仔细参考一下

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

public class BounceThread
{ public static void main(String[] args)
{ JFrame frame = new BounceThreadFrame();
frame.show();
}
}

class BounceThreadFrame extends JFrame
{ public BounceThreadFrame()
{ setSize(300, 200);
setTitle("Bounce");

  addWindowListener(new WindowAdapter()
     {  public void windowClosing(WindowEvent e)
        {  System.exit(0);
        }
     } );

  Container contentPane = getContentPane();
  canvas = new JPanel();
  contentPane.add(canvas, "Center");
  JPanel p = new JPanel();
  addButton(p, "Start",
     new ActionListener()
     {  public void actionPerformed(ActionEvent evt)
        {  Ball b = new Ball(canvas);
           b.start();
        }
     });

  addButton(p, "Close",
     new ActionListener()
     {  public void actionPerformed(ActionEvent evt)
        {  canvas.setVisible(false);
           System.exit(0);
        }
     });
  contentPane.add(p, "South");

}

public void addButton(Container c, String title,
ActionListener a)
{ JButton b = new JButton(title);
c.add(b);
b.addActionListener(a);
}

private JPanel canvas;
}

class Ball extends Thread
{ public Ball(JPanel b) { box = b; }

public void draw()
{ Graphics g = box.getGraphics();
g.fillOval(x, y, XSIZE, YSIZE);
g.dispose();
}

public void move()
{ if (!box.isVisible()) return;
Graphics g = box.getGraphics();
g.setXORMode(box.getBackground());
g.fillOval(x, y, XSIZE, YSIZE);
x += dx;
y += dy;
Dimension d = box.getSize();
if (x < 0)
{ x = 0; dx = -dx; }
if (x + XSIZE >= d.width)
{ x = d.width - XSIZE; dx = -dx; }
if (y < 0)
{ y = 0; dy = -dy; }
if (y + YSIZE >= d.height)
{ y = d.height - YSIZE; dy = -dy; }
g.fillOval(x, y, XSIZE, YSIZE);
g.dispose();
}

public void run()
{ try
{ draw();
for (int i = 1; i <= 1000; i++)
{ move();
sleep(5);
}
}
catch(InterruptedException e) {}
}

private JPanel box;
private static final int XSIZE = 10;
private static final int YSIZE = 10;
private int x = 0;
private int y = 0;
private int dx = 2;
private int dy = 2;
}

这个用计时器就可以实现 JAVA中的计时器Timer