编写程序显示一个时钟

package com.DisplayClock;

import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;

public class DisplayClock{
Thread hourThread = null;	//时针线程
Thread minuteThread = null; 	//分针线程
Thread secondThread = null;	//秒针线程
int currentHour = 0;	//获取当前时间中代表小时的数字值
int currentMinute = 0;	//获取当前时间中代表分钟的数字值
int currentSecond = 0;	//获取当前时间中代表秒数字值

int isRestart = 0;	//判断是否重新开始

public static void main(String[] args){
EventQueue.invokeLater(new Runnable()
{
public void run()
{
DrawFrame frame = new DrawFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);

}
});
}
}
class DrawFrame extends JFrame{
public DrawFrame()
{
setTitle("DisplayClock");//设置显示窗的标题
setSize(DEFAULT_WIDTH,DEFAULT_HEIGHT);//设置窗口的大小
DrawComponent component = new DrawComponent();
//创建要建立的图形的对象
add(component);
//将该图形加入到面板上
}
public static final int DEFAULT_WIDTH = 500;
//设置窗口的宽度
public static final int DEFAULT_HEIGHT = 500;
//设置窗口的高度
}
//建立时钟图形
class DrawComponent extends JComponent
{
public void paintComponent(Graphics g)
{
g.setColor(Color.blue);
Graphics2D g2 = (Graphics2D) g;
Ellipse2D circle = new Ellipse2D.Double();
circle.setFrameFromCenter(200,200,300,300);
g2.draw(circle);
//用来写表盘上的刻度
g.setColor(Color.green);
double jiaodu = Math.PI / 2;
double keX[] = new double[60];//存放表盘刻度的起始X坐标
double keY[] = new double[60];//存放表盘刻度的起始Y坐标
double duX[] = new double[60];//存放表盘刻度的终止X坐标
double duY[] = new double[60];//存放表盘刻度的终止Y坐标

for(int i = 0;i < 60;i++){
if(i == 0||i%5 == 0)
{
keX[i] = 200 + 80 * Math.cos(jiaodu);
keY[i] = 200 - 80 * Math.sin(jiaodu);
}
else
{
keX[i] = 200 + 90 * Math.cos(jiaodu);
keY[i] = 200 - 90 * Math.sin(jiaodu);
}
duX[i] = 200 + 100 * Math.cos(jiaodu);
duY[i] = 200 - 100 * Math.sin(jiaodu);
jiaodu = jiaodu - Math.PI / 30;
}
for(int j =0;j < 60;j++){
g2.draw(new Line2D.Double(keX[j],keY[j],duX[j],duY[j]));
}

//画12点的指针秒针

g.setColor(Color.black);

g2.draw(new Line2D.Double(200,200,200,130));

//画出分针
g.setColor(Color.BLUE);

g2.draw(new Line2D.Double(200,200,200,140));
//画出时针
g.setColor(Color.PINK);

g2.draw(new Line2D.Double(200,200,200,150));
}
}