clock.java

来自「我在学习JAVA的讲义」· Java 代码 · 共 41 行

import java.applet.Applet;
import java.awt.*;
import java.util.Calendar;

public class Clock extends Applet implements Runnable
{   Thread thread;
    Font font=new Font("Monospaced",Font.BOLD,64);
    int hour,minute,second;

    public void init( )
    {   if(thread==null)
        {   thread=new Thread(this);
            thread.start( );
        }
    }

    public void run( )
    {   for( ; ; )   //forever
        {   Calendar time=Calendar.getInstance( );
            hour=time.get(Calendar.HOUR);
            minute=time.get(Calendar.MINUTE);
            second=time.get(Calendar.SECOND);
            repaint(5);    //requests re-drawing every 5 milliseconds
        }
    }

    public void destory( )
    {   if(thread!=null)
        {   thread.stop( );
            thread=null;
        }
    }

    public void paint(Graphics g)
    {   g.setFont(font);
        String time=String.valueOf(hour)
                +":"+String.valueOf(minute)
                +":"+String.valueOf(second);
        g.drawString(time,50,50);
    }
}