clock.java

java时钟

import   java.util.*;   
  import   java.awt.*;   
  import   java.applet.*;   
  import   java.text.*;   
    
  /**   
    *   Time!   
    *   
    *   @author   Rachel   Gollub   
    *   @modified   Daniel   Peek   replaced   circle   drawing   calculation,   few   more   changes   
    */   
  public   class   Clock   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   
          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;   
          }   
    
          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();   
                  }   
          }   
    
          public   String   getAppletInfo()   {   
                  return   "Title:   A   Clock   \n"   
                          +   "Author:   Rachel   Gollub,   1995   \n"   
                          +   "An   analog   clock.";   
          }   
        
          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;   
          }   
  }