Java实现动态模拟时钟

import javax.swing.*;
import java.awt.*;
import java.util.*;
import java.lang.Thread;
import java.text.DecimalFormat;
 
public class StillClock extends JPanel {
 
 /**
  * @param args
  */
 private int hour;
 private int minute;
 private int second;
  
 //构造函数
 public StillClock() {
  setCurrentTime();
 }
 
 //返回小时
 public int getHour() {
  return hour;
 }
  
  
 public int getMinute() {
  return minute;
 }
  
  
  
 public int getSecond() {
  return second;
 }
  
  
 //绘制时钟
 protected void paintComponent(Graphics g) {
   
  super.paintComponent(g);
  //初始化
  int clockRadius = (int)(Math.min(getWidth(), getHeight()) * 0.8 * 0.5);
  int xCenter = getWidth() / 2;
  int yCenter = getHeight() / 2;
  //画圆
  g.setColor(Color.black);
  g.drawOval(xCenter - clockRadius, yCenter - clockRadius, 2 * clockRadius, 2 * clockRadius);
  g.drawString("12", xCenter - 5, yCenter - clockRadius + 15);
  g.drawString("9", xCenter - clockRadius + 3, yCenter + 5);
  g.drawString("3", xCenter + clockRadius - 10, yCenter + 3);
  g.drawString("6", xCenter - 3, yCenter + clockRadius - 3);
  //画秒针
  int sLength = (int)(clockRadius * 0.8);
  int xSecond = (int)(xCenter + sLength * Math.sin(second * (2 * Math.PI / 60)));
  int ySecond = (int)(yCenter - sLength * Math.cos(second * (2 * Math.PI / 60)));
   
  g.setColor(Color.red);
  g.drawLine(xCenter, yCenter, xSecond, ySecond);
   
  //画分针
  int mLenth = (int)(clockRadius * 0.65);
  int xMinute = (int)(xCenter + mLenth * Math.sin(minute * (2 * Math.PI / 60)));
  int yMinute = (int)(xCenter - mLenth * Math.cos(minute * (2 * Math.PI / 60)));
  g.setColor(Color.blue);
  g.drawLine(xCenter, yCenter, xMinute, yMinute);
   
  //画时针
  int hLength = (int)(clockRadius * 0.5);
  int xHour = (int)(xCenter + hLength * Math.sin((hour % 12 + minute / 60.0) * (2 * Math.PI / 12)));
  int yHour = (int)(yCenter - hLength * Math.cos((hour % 12 + minute / 60.0) * (2 * Math.PI / 12)));
  g.setColor(Color.green);
  g.drawLine(xCenter, yCenter, xHour, yHour);
   
  //画数字时钟
  g.setColor(Color.black);
  DecimalFormat s=new DecimalFormat("00");
  g.drawString(s.format(getHour()) + ":" + s.format(getMinute()) + ":" + s.format(getSecond()), xCenter - 22, yCenter - clockRadius - 15);
   
 }
  
 public void setCurrentTime() {
  Calendar calendar = new GregorianCalendar();
   
  this.hour = calendar.get(Calendar.HOUR_OF_DAY);
  this.minute = calendar.get(Calendar.MINUTE);
  this.second = calendar.get(Calendar.SECOND);
 }
  
  
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  JFrame frame = new JFrame("DiaplayClock");
    frame.setResizable(false);
  frame.setTitle("DiaplayClock");
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.setSize(300,350);
  frame.setVisible(true);
   
  while(true) {
   StillClock clock = new StillClock();
   frame.getContentPane().add(clock);
   clock.setVisible(true);
   frame.validate();
   try {
    Thread.sleep(1000);
     
   }
   catch (InterruptedException e) {
    e.printStackTrace(); 
   }
   clock.setVisible(false);
   frame.remove(clock);
   clock = null;
   frame.validate();
    
  }
 
 }
}