import java.awt.*;  import java.awt.event.*; import java.util.*; import javax.swing.event.*; import javax.swing.*; import javax.swing.Timer;/** * <p>Title: 時鐘</p> * <p>Description: 本實例演示使用圖形繪制一個圖形時鐘</p> * <p>Copyright: Copyright (c) 2003</p> * <p>Filename: Clock.java</p> * @author 杜江 * @version 1.0 */ public class Clock extends JFrame implements ActionListener{     Timer timer;    int x,y,old_X,old_Y, r,x0,y0,w,h,ang;     int sdo,mdo,hdo,old_M,old_H;     TimeZone tz =TimeZone.getTimeZone("JST");    final double RAD=Math.PI/180.0;   public static void main(String[] args){    Clock cl = new Clock();  }/** *<br>方法說明：實現ActionListener類必須過載的方法 *<br>輸入參數： *<br>返回類型： */   public void actionPerformed(ActionEvent e) {            timer.restart();    }/** *<br>方法說明：構造器，顯示窗體，并添加了一個秒表 *<br>輸入參數： *<br>返回類型： */   Clock(){    super("Clock");    setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);    setBackground(new Color(0,0,192));    setSize(300,300);    show();    int delay = 1000;    //窗體添加事件監聽，監聽秒表的觸發    ActionListener taskPerformer = new ActionListener() {      public void actionPerformed(ActionEvent evt) {         repaint();      }    };    new Timer(delay, taskPerformer).start();  }/** *<br>方法說明：繪制圖形 *<br>輸入參數： *<br>返回類型： */  public void paint( Graphics g ) {   	 Insets insets = getInsets();     int L0 = (insets.left)/2, T0 = (insets.top)/2;     int hh,mm,ss;      String st;      h=getSize().height;     //繪制圓形     g.setColor(Color.white);      g.drawOval(L0+30,T0+30,h-60,h-60);     g.drawOval(L0+32,T0+32,h-64,h-64);     r=h/2-30;     x0=30+r-5+L0;     y0=30+r-5-T0;     ang=60;     for (int i=1; i<=12; i++) {         x=(int)((r+10)*Math.cos(RAD*ang)+x0);        y=(int)((r+10)*Math.sin(RAD*ang)+y0);        g.drawString(""+i,x,h-y);        ang-=30;     }      x0=30+r+L0; y0=30+r+T0;     //獲取時間     Calendar now=Calendar.getInstance();     hh=now.get(Calendar.HOUR_OF_DAY);//小時     mm=now.get(Calendar.MINUTE);//分鐘     ss=now.get(Calendar.SECOND);// 秒     g.setColor(Color.pink);      g.fillRect(L0,T0,60,28);//填充的矩形     g.setColor(Color.blue);      if (hh < 10) st="0"+hh;     else st=""+hh;      if (mm < 10) st=st+":0"+mm; else st=st+":"+mm;      if (ss < 10) st=st+":0"+ss; else st=st+":"+ss;      g.drawString(st,L0,T0+25);     //計算時間和圖形的關系     sdo=90-ss*6;     mdo=90-mm*6;     hdo=90-hh*30-mm/2;     //擦除秒針     if (old_X > 0) {        g.setColor(getBackground());        g.drawLine(x0,y0,old_X,(h-old_Y));     } else {         old_M=mdo;        old_H=hdo;     }      //繪制秒針     g.setColor(Color.yellow);      x=(int)((r-8)*Math.cos(RAD*sdo)+x0);      y=(int)((r-8)*Math.sin(RAD*sdo)+y0)-2*T0;      g.drawLine(x0,y0,x,(h-y));          old_X=x;      old_Y=y;      //擦除分針和時針     if (mdo != old_M) {       line(g,old_M,(int)(r*0.7),getBackground());       old_M=mdo;     }      if (hdo != old_H) {       line(g,old_H,(int)(r*0.5),getBackground());       old_H=hdo;     }      //繪制分針     line(g,mdo,(int)(r*0.7),Color.green);     //繪制時針     line(g,hdo,(int)(r*0.5),Color.red);  } // end paint /** *<br>方法說明：繪制線，用于繪制時針和分針 *<br>輸入參數： *<br>返回類型： */   public void line(Graphics g, int t, int n, Color c) {       int [] xp = new int[4];      int [] yp = new int[4];       xp[0]=x0;      yp[0]=y0;      xp[1]=  (int)((n-10)*Math.cos(RAD*(t-4))+x0);       yp[1]=h-(int)((n-10)*Math.sin(RAD*(t-4))+y0);       xp[2]=  (int)( n    *Math.cos(RAD* t   )+x0);       yp[2]=h-(int)( n    *Math.sin(RAD* t   )+y0);       xp[3]=  (int)((n-10)*Math.cos(RAD*(t+4))+x0);       yp[3]=h-(int)((n-10)*Math.sin(RAD*(t+4))+y0);       g.setColor(c);       g.fillPolygon(xp,yp,4);   } }