Java实现一个简易的钟表

package com.diyitian.zaiyixun;

import java.awt.Graphics;
import java.util.Calendar;
import java.util.GregorianCalendar;
import javax.swing.JFrame;
import javax.swing.JPanel;
 
public class TimeTest extends JFrame {
 
   public TimeTest()
   {
      ClockPanel jp_clock=new ClockPanel();
      add(jp_clock);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setSize(400,400);
      this.setLocationRelativeTo(null);
      setVisible(true);
      Thread ClockRun=new Thread(jp_clock);
      ClockRun.start();
   }
   public static void main(String[] args) {
       
      new TimeTest();
   }
}
class ClockPanel extends JPanel implements Runnable
{
    private double CenterX,CenterY;
    private double Radius=100;
    private double HPointX,HPointY,MPointX,MPointY,SPointX,SPointY;
    private int Year,Month,Day,WeekDay,Hour,Minute,Second;
    private final double PI=3.141592653;
   public synchronized void paintComponent(Graphics g)
   {
      super.paintComponent(g);
      CenterX=this.getWidth()/2;
      CenterY=this.getHeight()/2;
     
      double HRadian=(PI/6)*Hour+(PI/360)*Minute+(PI/21600)*Second;
      double MRadian=(PI/30)*Minute+(PI/1800)*Second;
      double SRadian=(PI/30)*Second;
      HPointX=CenterX+Radius*0.6*Math.sin(HRadian);
      HPointY=CenterY-Radius*0.6*Math.cos(HRadian);
      MPointX=CenterX+Radius*0.8*Math.sin(MRadian);
      MPointY=CenterY-Radius*0.8*Math.cos(MRadian);
      SPointX=CenterX+Radius*Math.sin(SRadian);
      SPointY=CenterY-Radius*Math.cos(SRadian);
      //画表盘
      g.drawOval((int)(CenterX-Radius), (int)(CenterY-Radius), (int)(2*Radius),(int)(2*Radius));//椭圆
      g.drawString("12",(int)(CenterX),(int)(CenterY-Radius)+10);//字符串
      g.drawString("3",(int)(CenterX+Radius)-6 , (int)(CenterY));
      g.drawString("6", (int)(CenterX), (int)(CenterY+Radius));
      g.drawString("9",(int)(CenterX-Radius), (int)(CenterY));
    
      g.drawLine((int)(CenterX), (int)(CenterY), (int)(SPointX), (int)(SPointY));//画线
      g.drawLine((int)(CenterX), (int)(CenterY), (int)(MPointX), (int)(MPointY));
      g.drawLine((int)(CenterX), (int)(CenterY), (int)(HPointX), (int)(HPointY));
    
      g.drawString(WeekDay+" "+Month+" "+Day+" "+Hour+":"+Minute+":"+Second+" "+Year, 20, 350);
   }
   @Override
   public void run() {
        
      while(true)
      {
         try {
            setCurrentTime();
            repaint();
            Thread.sleep(1000);
         } catch (InterruptedException e) {
              
            e.printStackTrace();
         }
    
      }
     }
   public void setCurrentTime()
   {
      Calendar calendar=new GregorianCalendar();
      Year=calendar.get(Calendar.YEAR);
      Month=calendar.get(Calendar.MONTH);
      Day=calendar.get(Calendar.DAY_OF_MONTH);
      WeekDay=calendar.get(Calendar.DAY_OF_WEEK);
      Hour=calendar.get(Calendar.HOUR);
      Minute=calendar.get(Calendar.MINUTE);
      Second=calendar.get(Calendar.SECOND);
    
   }
}