timerd.java

一个简单的时钟显示程序！

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

public class Timerd
{
   public static void main(String[] args)
   {
      TimerTestFrame frame = new TimerTestFrame();
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//常用写法
      frame.show();
   }
}

class TimerTestFrame extends JFrame
{
    public TimerTestFrame()
   {
      setTitle("一个简易时钟");
      setSize(WIDTH, HEIGHT);
		setResizable(false);
      Container c = getContentPane();
      c.add(new ClockCanvas("Asia/Taipei"));//实例化Asia/Taipei地区的时间，加入到容器中

   }

   public static final int WIDTH = 212;
   public static final int HEIGHT = 280;
}

class ClockCanvas extends JPanel
{

   public ClockCanvas(String tz)
   {
     Calendar = new GregorianCalendar(TimeZone.getTimeZone(tz));
      //设置时间间隔为一秒，增加监听
      Timer t = new Timer(1000, new
         ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               Calendar.setTime(new Date());
               repaint();
            }
         });
      t.start();
   }

   public void paintComponent(Graphics g)
   {  double m=0.0;
	    Date t=new Date(); 
      int x=0,y=0,x2=0,y2=0;
      super.paintComponent(g);
   //显示时刻点（60条线段）
     for(int i=1;i<=60;i++)
		 {
		 	 m=i*Math.PI/30;
			 x=100+(int)(100*Math.sin(m));
			 y=100-(int)(100*Math.cos(m));
			 
       //判断是否是12、3、6、9这四个时刻
       if (i%15!=0)
      {
			g.drawLine(x,y,(int)(100+90*Math.cos(2 * Math.PI
         * (i - 15) / 60)),(int)(100+90*Math.sin(2 * Math.PI
         * (i - 15) / 60)));
			}
		 }
		 //显示12、3、6、9四个时刻线段（较其他56条线段长）以及数字
		 g.drawLine(100,0,100,20);
		 g.drawString("12",92,32);
 		 g.drawString("3",172,104);
		 g.drawString("6",97,177);
		 g.drawString("9",21,104);
		 g.drawLine(200,100,180,100);
		 g.drawLine(100,200,100,180);
		 g.drawLine(0,100,20,100);
     // 画时钟的一个圆
      g.drawOval(0, 0, 200, 200);
      //计算秒钟
      int seconds = Calendar.get(Calendar.HOUR) * 60 * 60
         + Calendar.get(Calendar.MINUTE) * 60
         + Calendar.get(Calendar.SECOND);
      //计算小时指针的角度
      double hourAngle = 2 * Math.PI
         * (seconds - 3 * 60 * 60) / (12 * 60 * 60);
      //计算分钟指针的角度
      double minuteAngle = 2 * Math.PI
         * (seconds - 15 * 60) / (60 * 60);
      //计算秒针指针的角度	 
      double secondAngle = 2 * Math.PI
         * (seconds - 15) / 60;
      //分别画小时、分钟、秒钟指针线段
      g.drawLine(100, 100, 100 + (int)(60
         * Math.cos(hourAngle)),
         100 + (int)(60 * Math.sin(hourAngle)));
      g.drawLine(100, 100, 100 + (int)(80
         * Math.cos(minuteAngle)),
         100 + (int)(80 * Math.sin(minuteAngle)));
      g.drawLine(100, 100, 100 + (int)(90  
         * Math.cos(secondAngle)),
         100 + (int)(90 * Math.sin(secondAngle)));
      g.drawString(t.toString(), 20, 220);
      g.drawString("制作 by  张友军",60,240);
   }

   private GregorianCalendar Calendar;

}