import java.util.*;
import java.awt.*;
import java.applet.*;
import java.text.*;
public class Exam5Test8 extends Applet implements Runnable {
 private volatile Thread timer; // The thread that displays clock
 private int lastxs, lastys, lastxm, lastym, lastxh, lastyh; // Dimensions used to draw hands
 private SimpleDateFormat formatter; // Formats the date displayed
 private String lastdate; // String to hold date displayed
 private Font clockFaceFont; // Font for number display on clock
 private Date currentDate; // Used to get date to display
 private Color handColor; // Color of main hands and dial
 private Color numberColor; // Color of second hand and numbers
 private int xcenter = 80, ycenter = 55; // Center position
 public void init() {
  int x, y;
  lastxs = lastys = lastxm = lastym = lastxh = lastyh = 0;
  formatter = new SimpleDateFormat("EEE MMM dd hh:mm:ss yyyy", Locale.getDefault());
  currentDate = new Date();
  lastdate = formatter.format(currentDate);
  clockFaceFont = new Font("Serif", Font.PLAIN, 14);
  handColor = Color.blue;
  numberColor = Color.darkGray;
  try {
   setBackground(new Color(Integer.parseInt(getParameter("bgcolor"),16)));
  } catch (NullPointerException e) {
  } catch (NumberFormatException e) {
  }
  try {
   handColor = new Color(Integer.parseInt(getParameter("fgcolor1"), 16));
  } catch (NullPointerException e) {
  } catch (NumberFormatException e) {
  }
  try {
   numberColor = new Color(Integer.parseInt(getParameter("fgcolor2"),16));
  } catch (NullPointerException e) {
  } catch (NumberFormatException e) {
  }
  resize(300, 300); // Set clock window size
 }
 // Paint is the main part of the program
 //更新时钟的显示时间
 public void update(Graphics g) {
  int xh, yh, xm, ym, xs, ys;
  int s = 0, m = 10, h = 10;
  String today;
  currentDate = new Date();
  formatter.applyPattern("s");
  try {
   s = Integer.parseInt(formatter.format(currentDate));
  } catch (NumberFormatException n) {
   s = 0;
  }
  formatter.applyPattern("m");
  try {
   m = Integer.parseInt(formatter.format(currentDate));
  } catch (NumberFormatException n) {
   m = 10;
  }
  formatter.applyPattern("h");
  try {
   h = Integer.parseInt(formatter.format(currentDate));
  } catch (NumberFormatException n) {
   h = 10;
  }
  // Set position of the ends of the hands
  xs = (int) (Math.cos(s * Math.PI / 30 - Math.PI / 2) * 45 + xcenter);
  ys = (int) (Math.sin(s * Math.PI / 30 - Math.PI / 2) * 45 + ycenter);
  xm = (int) (Math.cos(m * Math.PI / 30 - Math.PI / 2) * 40 + xcenter);
  ym = (int) (Math.sin(m * Math.PI / 30 - Math.PI / 2) * 40 + ycenter);
  xh = (int) (Math.cos((h * 30 + m / 2) * Math.PI / 180 - Math.PI / 2) * 30 + xcenter);
  yh = (int) (Math.sin((h * 30 + m / 2) * Math.PI / 180 - Math.PI / 2) * 30 + ycenter);
  // Get the date to print at the bottom
  formatter.applyPattern("EEE MMM dd HH:mm:ss yyyy");
  today = formatter.format(currentDate);
  g.setFont(clockFaceFont);
  // Erase if necessary
  g.setColor(getBackground());
  if (xs != lastxs || ys != lastys) {
   g.drawLine(xcenter, ycenter, lastxs, lastys);
   g.drawString(lastdate, 5, 125);
  }
  if (xm != lastxm || ym != lastym) {
   g.drawLine(xcenter, ycenter - 1, lastxm, lastym);
   g.drawLine(xcenter - 1, ycenter, lastxm, lastym);
  }
  if (xh != lastxh || yh != lastyh) {
   g.drawLine(xcenter, ycenter - 1, lastxh, lastyh);
   g.drawLine(xcenter - 1, ycenter, lastxh, lastyh);
  }
  // Draw date and hands
  g.setColor(numberColor);
  g.drawString(today, 5, 125);
  g.drawLine(xcenter, ycenter, xs, ys);
  g.setColor(handColor);
  g.drawLine(xcenter, ycenter - 1, xm, ym);
  g.drawLine(xcenter - 1, ycenter, xm, ym);
  g.drawLine(xcenter, ycenter - 1, xh, yh);
  g.drawLine(xcenter - 1, ycenter, xh, yh);
  lastxs = xs;
  lastys = ys;
  lastxm = xm;
  lastym = ym;
  lastxh = xh;
  lastyh = yh;
  lastdate = today;
  currentDate = null;
 }
 //描绘出时钟表
 public void paint(Graphics g) {
  g.setFont(clockFaceFont);
  // Draw the circle and numbers
  g.setColor(handColor);
  g.drawArc(xcenter - 50, ycenter - 50, 100, 100, 0, 360);
  g.setColor(numberColor);
  g.drawString("9", xcenter - 45, ycenter + 3);
  g.drawString("3", xcenter + 40, ycenter + 3);
  g.drawString("12", xcenter - 5, ycenter - 37);
  g.drawString("6", xcenter - 3, ycenter + 45);
  // Draw date and hands
  g.setColor(numberColor);
  g.drawString(lastdate, 5, 125);
  g.drawLine(xcenter, ycenter, lastxs, lastys);
  g.setColor(handColor);
  g.drawLine(xcenter, ycenter - 1, lastxm, lastym);
  g.drawLine(xcenter - 1, ycenter, lastxm, lastym);
  g.drawLine(xcenter, ycenter - 1, lastxh, lastyh);
  g.drawLine(xcenter - 1, ycenter, lastxh, lastyh);
 }
 public void start() {
  timer = new Thread(this);
  timer.start();
 }
 public void stop() {
  timer = null;
 }
 public void run() {
  Thread me = Thread.currentThread();
  while (timer == me) {
   try {
    Thread.currentThread().sleep(100);
   } catch (InterruptedException e) {
   }
   repaint();
  }
 }
 /*返回有关此 applet 的信息。applet 应该重写此方法，返回包含有关 applet 的作者、版本和版权信息的 String。
 Applet 类提供的此方法实现返回 null
  */
 public String getAppletInfo() {
  return "Title: A Clock \n" + "Author: 陈金林, 2011 \n"
    + "An analog clock.";
 }
 /*返回此 applet 理解的关于参数的信息。applet 应该重写此方法，返回描述这些参数的 String 数组。
 数组的每个元素应该是三个 String 的集合，包括名称、类型和描述。
  */
 public String[][] getParameterInfo() {
  String[][] info = {
    { "bgcolor", "hexadecimal RGB number",
      "The background color. Default is the color of your browser." },
    { "fgcolor1", "hexadecimal RGB number",
      "The color of the hands and dial. Default is blue." },
    { "fgcolor2", "hexadecimal RGB number",
      "The color of the second hand and numbers. Default is dark gray." } };
  return info;
 }
}