Java简单时钟例子

import java.util.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class Clock1 extends JFrame implements Runnable {
 private static final long serialVersionUID = 1L;

 public Clock1() {
  enableEvents(AWTEvent.WINDOW_EVENT_MASK);
  try {
   jbInit();
  }
  catch (Exception e) {
   e.printStackTrace();
  }
 }
 Thread thread1;    // 定义线程对象
 Color handColor;    // 定义表示时针、分针和秒针颜色的变量
 Color numberColor;   // 定义表示时钟数字颜色的变量
 JLabel jLabel1 = new JLabel();

 public void init() {
  int x, y;
  handColor = Color.blue;
  numberColor = Color.darkGray;
  setBackground(Color.white);
 }

 // paint is the main part of the program
 public void paint(Graphics g) {
  int xh, yh, xm, ym, xs, ys, s = 0, m = 10, h = 0, xpoint, ypoint;
  int day, month, year, weekday;
  Calendar c1 = Calendar.getInstance();
  // 获得当前时间
  s = c1.get(Calendar.SECOND);
  m = c1.get(Calendar.MINUTE);
  h = c1.get(Calendar.HOUR_OF_DAY);
  // 获得当前日期
  day = c1.get(Calendar.DATE);
  month = c1.get(Calendar.MONTH) + 1;
  year = c1.get(Calendar.YEAR);
  weekday = c1.get(Calendar.DAY_OF_WEEK) - 1;
  // 在标签控件上显示日期和时间
  jLabel1.setText("    " + year + "年" + month + "月" + day + "日" + "    " + "星期" + weekday + "    " + h + ":" + m + ":" + s);
  xpoint = 130;
  ypoint = 100;
  // 计算时针、分针和秒针的位置
  xs = (int) (Math.cos(s * 3.14f / 30 - 3.14f / 2) * 45 + xpoint);
  ys = (int) (Math.sin(s * 3.14f / 30 - 3.14f / 2) * 45 + ypoint);
  xm = (int) (Math.cos(m * 3.14f / 30 - 3.14f / 2) * 40 + xpoint);
  ym = (int) (Math.sin(m * 3.14f / 30 - 3.14f / 2) * 40 + ypoint);
  xh = (int) (Math.cos((h * 30 + m / 2) * 3.14f / 180 - 3.14f / 2) * 30 + xpoint);
  yh = (int) (Math.sin((h * 30 + m / 2) * 3.14f / 180 - 3.14f / 2) * 30 + ypoint);
  // 绘制时钟背景
  g.setColor(handColor);
  g.clearRect(0, 0, 260, 200);
  g.drawOval(xpoint / 2 + 10, ypoint / 2 - 5, 110, 110);
  g.setColor(numberColor);
  g.drawString("9", xpoint - 45, ypoint + 3);
  g.drawString("3", xpoint + 40, ypoint + 3);
  g.drawString("12", xpoint - 5, ypoint - 37);
  g.drawString("6", xpoint - 3, ypoint + 45);
  g.setColor(getBackground());

  g.setColor(numberColor);
  g.drawString("", 5, 125);
  // 绘制时针、分针和秒针
  g.drawLine(xpoint, ypoint, xs, ys);
  g.setColor(handColor);
  g.drawLine(xpoint, ypoint, xm, ym);
  g.drawLine(xpoint, ypoint, xh, yh);
 }

 // 定义线程的run方法
 public void run() {
  Thread me = Thread.currentThread();
  while (thread1 == me) {
   try {
    Thread.currentThread().sleep(100);
   }
   catch (InterruptedException e) {
    e.printStackTrace();
   }
   repaint();
  }
 }

 // 开始执行线程
 public void start() {
  thread1 = new Thread(this);
  thread1.start();
 }

 // 停止线程
 public void stop() {
  thread1 = null;
 }

 public void update(Graphics g) {
  paint(g);
 }

 private void jbInit() throws Exception {
  this.getContentPane().add(jLabel1, BorderLayout.SOUTH);
 }

 protected void processWindowEvent(WindowEvent e) {
  super.processWindowEvent(e);
  if (e.getID() == WindowEvent.WINDOW_CLOSING) {
   System.exit(0);
  }
 }
 public static void main(String[] args) {
  Clock1 clock1 = new Clock1();
  clock1.init();
  clock1.start();
  clock1.setSize(280, 230);
  clock1.setResizable(false);
  clock1.setVisible(true);
 }
}

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