stopwatch.java

Java程序设计技巧与开发实例附书源代码。

import javax.swing.*;

public class StopWatch
        extends JLabel
        implements Runnable
{
    private Thread thread = null;
    private int count = 0;
    public StopWatch()
    {
        super("Time expired:   0 seconds");
    }

    public void start()
    {
        count = 0;
        thread = new Thread(this);
        thread.start();
    }

    public void stop()
    {
        thread = null;
    }

    public void run()
    {
        Thread currentThread = Thread.currentThread();
        while (thread == currentThread)
        {
            setText("Expired: " + count + " seconds");
            count++;
            try
            {
                thread.sleep(1000);
            }
            catch (InterruptedException ie)
            {
                System.err.println("Error: " + ie);
            }
        }
    }
}