大家一起为奥运出力，看我的奥运倒计时问题出在哪里？ （applet，线程的关闭）

Question

程序功能实现一个可以精确到秒的倒计时，所以想用到thread sleep()一下，实现每秒获取一次系统时间。不过这样一来在网页中调用它就关不掉了，必须还得去进程里结束。
欢迎大虾指正！
import java.applet.Applet;
import java.awt.*;
import java.util.Calendar;
import java.util.GregorianCalendar;
import javax.swing.* ;
public class Data extends Applet { boolean b = true ;
Calendar calendar = new GregorianCalendar();
Calendar examdate = new GregorianCalendar(2008,7,8,20,0,0);
Thread t = new Thread();
public void run() {
}

public void paint(Graphics g) {
int sign=0;
int signy=0;
t.start();
try
{
while( calendar.before( examdate ) && b )
{
g.clearRect(5,5,250,70);
g.drawRect(5,5,250,70);
g.setColor(Color.red);
g.drawString( "  现在时刻 :  " +(calendar.get(Calendar.MONTH)+1)+" 月 "+
calendar.get(Calendar.DAY_OF_MONTH) +" 日 "+ calendar.get(Calendar.HOUR_OF_DAY)+
" 时 "+calendar.get(Calendar.MINUTE)+" 分 "+ calendar.get(Calendar.SECOND)+" 秒 ",15,30); if(calendar.get(Calendar.YEAR)!=2008)
signy=1;
else
signy=0;
if(calendar.get(Calendar.HOUR_OF_DAY)>=8)
{
sign=1;
}
else
sign=0; g.drawString( "  离奥运开幕还有 :  "+(365* signy +19-calendar.get(Calendar.DAY_OF_YEAR)-sign)+" 天 "+
(24*sign+7-calendar.get(Calendar.HOUR_OF_DAY)) +" 时 "+ (59-calendar.get(Calendar.MINUTE))+
" 分 " + (60-calendar.get(Calendar.SECOND)) + " 秒 " ,15,60); t.sleep(1000);
calendar = new GregorianCalendar();
} g.drawString("         感 谢 使 用 08 奥 运 倒 计 时 ",15,30);
g.drawString("                   祝  中  国  成  功 !",15,60);
}
catch(InterruptedException e)
{
}
}

public void stop() {
b=false;
System.exit(0);
} public void destroy() {
b=false;
System.exit(0);
}
}

Answer 1

写的就不对 
你在paint里面 不停的循环
主线程都被你阻塞了

Answer 2

/**
 * 
 */
package test3;import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.util.Calendar;
import java.util.GregorianCalendar;public class Data extends Applet
{    boolean  b        = true;    Calendar calendar = new GregorianCalendar();    Calendar examdate = new GregorianCalendar(2008, 7, 8, 20, 0, 0);//    Thread   t        = new Thread();    public void run()
    {
    }    public void init()
    {
        // this.set        new Thread()
        {
            public void run()
            {
                while (calendar.before(examdate) && b)
                {
                    try
                    {                        Thread.sleep(1000);
                    }
                    catch (InterruptedException e)
                    {
                        e.printStackTrace();
                    }
                    calendar = new GregorianCalendar();
                    Data.this.repaint();
                    
                }
            }
        }.start();
    }    public void paint(Graphics g)
    {
        int sign = 0;
        int signy = 0;
//        t.start();        g.clearRect(5, 5, 250, 130);
        g.drawRect(5, 5, 250, 130);
        g.setColor(Color.red);
        g.drawString("  现在时刻 :  " + (calendar.get(Calendar.MONTH) + 1) + " 月 "
                + calendar.get(Calendar.DAY_OF_MONTH) + " 日 "
                + calendar.get(Calendar.HOUR_OF_DAY) + " 时 "
                + calendar.get(Calendar.MINUTE) + " 分 "
                + calendar.get(Calendar.SECOND) + " 秒 ", 15, 30);        if (calendar.get(Calendar.YEAR) != 2008)
            signy = 1;
        else
            signy = 0;
        if (calendar.get(Calendar.HOUR_OF_DAY) >= 8)
        {
            sign = 1;
        }
        else
            sign = 0;        g.drawString(
                "  离奥运开幕还有 :  "
                        + (365 * signy + 19
                                - calendar.get(Calendar.DAY_OF_YEAR) - sign)
                        + " 天 "
                        + (24 * sign + 7 - calendar.get(Calendar.HOUR_OF_DAY))
                        + " 时 " + (59 - calendar.get(Calendar.MINUTE)) + " 分 "
                        + (60 - calendar.get(Calendar.SECOND)) + " 秒 ", 15, 60);        g.drawString("         感 谢 使 用 08 奥 运 倒 计 时 ", 15, 90);
        g.drawString("                   祝  中  国  成  功 !", 15, 120);    }    public void stop()
    {
        b = false;
        System.exit(0);
    }    public void destroy()
    {
        b = false;
        System.exit(0);
    }
}

Answer 3

谢谢insiku(不问世事好多年~~|| PM我时请附上帖子地址) 的指点。
小弟不胜感激，分数已加。另外希望本贴对以后像我这样的菜鸟有所帮助！