stillclock.java

这是本人开发的一个小时钟 主要涉及到java的多线程技术

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

public class StillClock extends JPanel
  {
     protected TimeZone timeZone;
     protected int xCenter,yCenter;
     protected int clockRadius;
     protected DateFormat formatter;
    
     public StillClock()
       {
         this(Locale.getDefault(),TimeZone.getDefault());
       }
     public StillClock(Locale locale,TimeZone timeZone)
       {
         setLocale(locale);
         this.timeZone=timeZone; 
       }
     //当地区变化时用来设置local属性

     public void setLocaleIn(Locale locale)
       {
          setLocale(locale);
       }   
     public void setTimeZoneID(String newTimeZoneID)
       {
          timeZone=TimeZone.getTimeZone(newTimeZoneID); 
       }
     public void paintComponent(Graphics g)
       {
         super.paintComponent(g);
         clockRadius=(int)(Math.min(getSize().width,getSize().height)*0.7*0.5);
         xCenter=(getSize().width)/2;
         yCenter=(getSize().height)/2;
        
         //draw Circle
         g.setColor(Color.black);
         g.drawOval(xCenter-clockRadius,yCenter-clockRadius,2*clockRadius,2*clockRadius);
         g.drawString("12",xCenter-5,yCenter-clockRadius);
         g.drawString("6",xCenter-3,yCenter+clockRadius+10);
         g.drawString("9",xCenter-clockRadius-10,yCenter+3);
         g.drawString("3",xCenter+clockRadius,yCenter+3); 
    
         //get Current time using GregorianCalendar
         GregorianCalendar cal=new GregorianCalendar(timeZone);
         
         //draw second minute hour hand
         int second=(int)cal.get(GregorianCalendar.SECOND);
          //System.out.println(cal.get(GregorianCalendar.SECOND));
         int sLength=(int)(clockRadius*0.9);
         int xSecond=(int)(xCenter+sLength*Math.sin(second*(2*Math.PI/60))); 
         int ySecond=(int)(yCenter-sLength*Math.cos(second*(2*Math.PI/60)));
         g.setColor(Color.red);
         g.drawLine(xCenter,yCenter,xSecond,ySecond);

         //箭头
         int xx1Second=(int)(xCenter+0.8*sLength*Math.sin(second*(2*Math.PI/60))); 
         int yy1Second=(int)(yCenter-0.9*sLength*Math.cos(second*(2*Math.PI/60)));
         
         g.drawLine(xSecond,ySecond,xx1Second,yy1Second);
         int xx2Second=(int)(xCenter+0.9*sLength*Math.sin(second*(2*Math.PI/60))); 
         int yy2Second=(int)(yCenter-0.8*sLength*Math.cos(second*(2*Math.PI/60)));
         
         g.drawLine(xSecond,ySecond,xx2Second,yy2Second);
         
         //minute
         int minute=(int)cal.get(GregorianCalendar.MINUTE);
         //System.out.println(cal.get(GregorianCalendar.MINUTE));
         int mLength=(int)(clockRadius*0.6);
         int xMinute=(int)(xCenter+mLength*Math.sin(minute*(2*Math.PI/60)));
         int yMinute=(int)(yCenter-mLength*Math.cos(minute*(2*Math.PI/60)));
         g.setColor(Color.blue);
         g.drawLine(xCenter,yCenter,xMinute,yMinute);

         //箭头
         int xx1Minute=(int)(xCenter+0.8*mLength*Math.sin(minute*(2*Math.PI/60)));
         int yy1Minute=(int)(yCenter-0.9*mLength*Math.cos(minute*(2*Math.PI/60)));
         
         g.drawLine(xMinute,yMinute,xx1Minute,yy1Minute);
         int xx2Minute=(int)(xCenter+0.9*mLength*Math.sin(minute*(2*Math.PI/60)));
         int yy2Minute=(int)(yCenter-0.8*mLength*Math.cos(minute*(2*Math.PI/60)));
         
         g.drawLine(xMinute,yMinute,xx2Minute,yy2Minute);
        
          //hour
         int hour=(int)cal.get(GregorianCalendar.HOUR);
         //System.out.println(cal.get(GregorianCalendar.HOUR));
         int hLength=(int)(clockRadius*0.4);
         int xHour=(int)(xCenter+hLength*Math.sin(hour*(2*Math.PI/12)));
         int yHour=(int)(yCenter-hLength*Math.cos(hour*(2*Math.PI/12)));
         g.setColor(Color.green);
         g.drawLine(xCenter,yCenter,xHour,yHour);
          
         //箭头
         int xx1Hour=(int)(xCenter+0.8*hLength*Math.sin(hour*(2*Math.PI/12)));
         int yy1Hour=(int)(yCenter-0.9*hLength*Math.cos(hour*(2*Math.PI/12)));
         
         g.drawLine(xHour,yHour,xx1Hour,yy1Hour);
         int xx2Hour=(int)(xCenter+0.9*hLength*Math.sin(hour*(2*Math.PI/12)));
         int yy2Hour=(int)(yCenter-0.8*hLength*Math.cos(hour*(2*Math.PI/12)));
         
         g.drawLine(xHour,yHour,xx2Hour,yy2Hour);


         //format
         formatter=DateFormat.getDateTimeInstance                                               (DateFormat.MEDIUM,DateFormat.LONG,getLocale());
         formatter.setTimeZone(timeZone);
        
         //display the current time
         g.setColor(Color.red);
         String today=formatter.format(cal.getTime());
         FontMetrics fm=g.getFontMetrics();
         g.drawString(today,(getSize().width-fm.stringWidth(today))/2,yCenter+clockRadius+30);
         
       
       }
       
  }