java实现时钟

以下时代码，注意导包

package com.js.ai.modules.pointwall.testxfz;
 
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
 
import javax.swing.JFrame;
 
public class ClockDemo extends JFrame implements Runnable{
Thread clock;
final int Xpoint=180;
final int Ypoint=180;
final int R=80;
int xHour=0,yHour=0,xSecond=0,ySecond=0,xMin=0,yMin=0;
public ClockDemo() {
    super("数字时钟");
    setFont(new Font("宋体", Font.BOLD, 20));
    start();
    setSize(360, 360);
    setVisible(true);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void start()//开始进程
{
    if(clock==null)//如果进程为空值
    {
        clock=new Thread(this); //实例化进程
        clock.start();//开始进程
    }
}
public void run()//运行进程
{
    while(clock!=null){
        repaint(); //调用paint方法重绘界面
        try {
            Thread.sleep(1000);//线程暂停一秒(1000毫秒)
        } catch (InterruptedException e) {
             
            e.printStackTrace();
        }
    }
     
}
public void stop()//停止进程
{
    clock=null;
}
public void paint(Graphics g)//重载组件的paint方法
{
    Graphics2D g2=(Graphics2D) g;//得到Graphics2D对象
    DateFormat dateFormat=DateFormat.getDateInstance(DateFormat.FULL);
    Calendar now =new GregorianCalendar();//实例化日历对象
    now.setTime(new Date());//dateFormat.format(now.getTime())
    String timeInfo="";//输出信息
    int hour=now.get(Calendar.HOUR_OF_DAY);//得到小时数
    int minute=now.get(Calendar.MINUTE);//得到分数
    int second=now.get(Calendar.SECOND);//得到秒数
    if(hour<=9)
        timeInfo+="0"+hour+":";//格式化输出
    else
        timeInfo+=hour+":";
    if(minute<=9)
        timeInfo+="0"+minute+":";
    else
        timeInfo+=minute+":";
    if(second<=9)
        timeInfo+="0"+second+":";
    else
        timeInfo+=second+":";
    g.setColor(Color.yellow);//设置当前颜色为黄色
    Dimension dim=getSize();//得到窗口尺寸
    g.fillRect(0, 0, dim.width, dim.height);//填充背景
    g.setColor(Color.red);//设置当前颜色
    g.drawString(timeInfo, 130, 340);//显示时间字符串
    g.setColor(Color.green);
    g.drawString(dateFormat.format(now.getTime()),20,60);
    g.setColor(Color.black);
    g.setFont(new Font("SAN_SERIF", Font.BOLD, 15));
    for(int i=0,num=12;i<360;i+=6){
        double alfa=Math.toRadians(i);
        int xPox=Xpoint+(int)(R*Math.sin(alfa));
        int yPos=Ypoint-(int)(R*Math.cos(alfa));
        if(i==0)
        {
        if (num%3==0)
        g.setColor(Color.red); // 数字3,6,9,12为红色
        else
        g.setColor(Color.black); // 其余数字为黑色
        g.drawString(""+num,xPox-5,yPos+3); // 写数字
        num=(num+1);
        }
        else {
            g.setColor(Color.black);
            g.drawString(".",xPox,yPos);
        }
    }
    g.setColor(Color.black);
    g.fillOval(Xpoint-4,Ypoint-4,8,8);
    //画秒针
    xSecond=(int)(Xpoint+(R-10)*Math.sin(second*(2*Math.PI/60)));
    ySecond=(int)(Ypoint-(R-10)*Math.cos(second*(2*Math.PI/60)));
    g.setColor(Color.red);
    g.drawLine(Xpoint,Ypoint,xSecond,ySecond);
    //画分针
    xMin=(int)(Xpoint+(R-20)*Math.sin((minute+second/60)*(2*Math.PI/60)));
    yMin=(int)(Ypoint-(R-20)*Math.cos((minute+second/60)*(2*Math.PI/60)));
    g.setColor(Color.red);
    g.drawLine(Xpoint,Ypoint,xMin,yMin);
    //画时针
    xHour=(int)(Xpoint+(R-30)*Math.sin((hour+minute/60+second/60/60)*(2*Math.PI/12)));
    yHour=(int)(Ypoint-(R-30)*Math.cos((hour+minute/60+second/60/60)*(2*Math.PI/12)));
    g.setColor(Color.red);
    g.drawLine(Xpoint,Ypoint,xHour,yHour);
}
public static void main(String[] args)
{
new ClockDemo();
}
}
```