swingclock.java

《Java与模式》一书的源代码

package com.javapatterns.observertimer.clock;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import javax.swing.*;



public class SwingClock extends java.applet.Applet
{
    private Timer clock = new Timer(1000,
        new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                synchronized(SwingClock.this)
                {
                    repaint();
                }
            }
        });

    public void init()
    {
        setBackground(Color.green);
        setFont(new Font("TimesRoman", Font.BOLD, 36));

    }

    public void paint(Graphics g)
    {
        Calendar cal = Calendar.getInstance();
        Date date = cal.getTime();
        DateFormat dateFormatter = DateFormat.getTimeInstance();
        g.drawString(dateFormatter.format(date), 5, 100);
    }

    public SwingClock() throws InterruptedException
    {
        clock.start();
    }
}