swingclock.java

来自「java与模式 一书的源码」· Java 代码 · 共 49 行

package com.javapatterns.observertimer.clock;

import javax.swing.Timer;
import java.text.DateFormat;

import java.awt.Font;
import java.awt.Graphics;
import java.awt.Color;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

import java.util.Calendar;
import java.util.Date;

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();
    }
}