10. 9. 1. 丑陋的表 Create a thread to update Swing

 

import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.text.SimpleDateFormat;import java.util.Date;import java.util.Locale;import javax.swing.JFrame;import javax.swing.JPanel;public class Clock extends JPanel implements Runnable{Thread thread = null;//SimpleDateFormat 是一个以与语言环境有关的方式来格式化和解析日期的具体类。SimpleDateFormat formatter = new SimpleDateFormat("s",Locale.getDefault());Date currentDate;//这个时间是 java.util.Dateint xcenter = 100, ycenter = 100, lastxs = 0, lastys = 0, lastxm = 0, lastym = 0, lastxh = 0,lastyh = 0;private void drawStructure(Graphics g){//画这个表圆，表针g.setFont(new Font("TimesRoman", Font.PLAIN, 14));g.setColor(Color.blue);g.drawOval(xcenter-50, ycenter-50, 100, 100);g.setColor(Color.DARK_GRAY);g.drawString("9", xcenter - 45, ycenter + 3);    g.drawString("3", xcenter + 40, ycenter + 3);    g.drawString("12", xcenter - 5, ycenter - 37);//这几个位置好难弄    g.drawString("6", xcenter - 3, ycenter + 45);}public void paint(Graphics g){int xhour, yhour, xminute, yminute, xsecond, ysecond, second, minute, hour;    drawStructure(g);    currentDate = new Date();    formatter.applyPattern("s");    second = Integer.parseInt(formatter.format(currentDate));    formatter.applyPattern("m");    minute = Integer.parseInt(formatter.format(currentDate));    formatter.applyPattern("h");    hour = Integer.parseInt(formatter.format(currentDate));    xsecond = (int) (Math.cos(second * 3.14f / 30 - 3.14f / 2) * 45 + xcenter);    ysecond = (int) (Math.sin(second * 3.14f / 30 - 3.14f / 2) * 45 + ycenter);    xminute = (int) (Math.cos(minute * 3.14f / 30 - 3.14f / 2) * 40 + xcenter);    yminute = (int) (Math.sin(minute * 3.14f / 30 - 3.14f / 2) * 40 + ycenter);    xhour = (int) (Math.cos((hour * 30 + minute / 2) * 3.14f / 180 - 3.14f / 2) * 30 + xcenter);    yhour = (int) (Math.sin((hour * 30 + minute / 2) * 3.14f / 180 - 3.14f / 2) * 30 + ycenter);    // Erase if necessary, and redraw    g.setColor(Color.lightGray);    if (xsecond != lastxs || ysecond != lastys) {      g.drawLine(xcenter, ycenter, lastxs, lastys);    }    if (xminute != lastxm || yminute != lastym) {      g.drawLine(xcenter, ycenter - 1, lastxm, lastym);      g.drawLine(xcenter - 1, ycenter, lastxm, lastym);    }    if (xhour != lastxh || yhour != lastyh) {      g.drawLine(xcenter, ycenter - 1, lastxh, lastyh);      g.drawLine(xcenter - 1, ycenter, lastxh, lastyh);    }        g.setColor(Color.darkGray);    g.drawLine(xcenter, ycenter, xsecond, ysecond);       g.setColor(Color.red);    g.drawLine(xcenter, ycenter - 1, xminute, yminute);    g.drawLine(xcenter - 1, ycenter, xminute, yminute);    g.drawLine(xcenter, ycenter - 1, xhour, yhour);    g.drawLine(xcenter - 1, ycenter, xhour, yhour);    lastxs = xsecond;    lastys = ysecond;    lastxm = xminute;    lastym = yminute;    lastxh = xhour;    lastyh = yhour;}public void start(){if(thread == null){thread = new Thread(this);thread.start();}}public void stop(){thread = null;}public void run() {while(thread != null){try{Thread.sleep(100);}catch(InterruptedException e){}repaint();}thread = null;}public void update(Graphics g){paint(g);}public static void main(String[] args) {JFrame window = new JFrame("我是一只丑陋的表");    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);    window.setBounds(30, 30, 300, 300);    Clock clock = new Clock();    window.getContentPane().add(clock);    window.setVisible(true);    clock.start();}}