Java 画时钟遇到的问题及解决方案

import javax.swing.*;

import java.awt.*;

import java.awt.event.actionevent;

import java.awt.event.actionlistener;

import java.net.http.websocket;

import java.net.http.websocket.listener;

import java.util.calendar;

import java.util.date;

public class clockframe extends jframe {

     clockframe() {

         setresizable( false );

         setdefaultcloseoperation(jframe.exit_on_close);

         setsize( 400 , 400 );

         setlocationrelativeto( null );

     }

     public static void main(string[] args) {

         clockframe frame = new clockframe();

         clockpanel panel = new clockpanel();

         frame.add(panel);

         panel.setcalendar();

         frame.setvisible( true );

     }

}

class clockpanel extends jpanel {

     //        画h:m:s;

     calendar calendar = calendar.getinstance();

     int s = calendar.get(calendar.second);

     int m = calendar.get(calendar.minute);

     int h = calendar.get(calendar.hour);

     public void setcalendar() {

         timer timer = new timer( 1000 , new listener());

         timer.start();

     }

     class listener implements actionlistener {

         @override

         public void actionperformed(actionevent e) {

             s++;

             if (s == 60 ) {

                 m++;

                 s = 0 ;

             }

             if (m == 60 ) {

                 h++;

                 m = 0 ;

             }

             repaint();

         }

     }

     //run 动态

     int sx = 190 ;

     int sy = 70 ;

     clockpanel() {

         setbackground(color.gray);

     }

     public void paint(graphics g) {

         super .paintcomponent(g);

//        圆

         g.drawoval( 83 , 57 , 220 , 220 );

         //画点

         g.filloval( 190 , 170 , 5 , 5 ); //center

         for ( int i = 12 ; i > 0 ; i--) {

             g.filloval(( int ) ( 190 + 100 * math.sin(math.pi / 6 * i)), ( int ) ( 170 + 100 * math.cos(math.pi / 6 * i)), 5 , 5 );

             string time = i + "" ;

             g.setfont( new font( "微软雅黑" , font.bold, 15 ));

             g.drawstring(time, ( int ) ( 190 + math.sin(math.pi / 6 * i) * 100 ), ( int ) ( 170 - math.cos(math.pi / 6 * i) * 100 ));

         }

         g.setfont( new font( "微软雅黑" , font.bold, 20 ));

         string s = s > 10 ? s + "" : "0" + s;

         string m = m > 10 ? m + "" : "0" + m;

         string h = h > 10 ? h + "" : "0" + h;

         g.drawstring( "现在是中国时间" + h + ":" + m + ":" + s, 80 , 40 );

         final basicstroke stokeline = new basicstroke( 3 .0f);

         graphics2d g2d = (graphics2d) g;

         g2d.setstroke(stokeline);

         g.setcolor(color.black);

         g.drawline( 190 , 170 , ( int ) ( 190 + (math.cos((s * math.pi / 30 ) - math.pi / 2 ) * 100 )), ( int ) ( 170 + (math.sin((s * math.pi / 30 - math.pi / 2 )) * 100 )));

         g.setcolor(color.blue);

         g.drawline( 190 , 170 , ( int ) ( 190 + (math.cos((m * math.pi / 30 - math.pi / 2 )) * 100 )), ( int ) ( 170 + (math.sin((m * math.pi / 30 - math.pi / 2 )) * 100 )));

         g.setcolor(color.green);

         g.drawline( 190 , 170 , ( int ) ( 190 + (math.cos((h * math.pi / 12 )) * 100 )), ( int ) ( 170 + ((math.sin(h * math.pi / 12 )) * 100 )));

     }

}