package cn.edu.njit.thread;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSpinner;
import javax.swing.SpinnerDateModel;

public class BackTime
{
    public static void main(String[] args)
    {
        BackTimeFrame f = new BackTimeFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
    }
}

class BackTimeFrame extends JFrame
{
    public BackTimeFrame()
    {
        setTitle("倒计时");
        setSize(600, 600);
        setLocation(500, 200);
        BackTimePanel p = new BackTimePanel();
        add(p);
    }
}

class BackTimePanel extends JPanel
{
    private JSpinner sp;
    private JButton b;
    boolean time = true;
    GregorianCalendar gc;

    public BackTimePanel()
    {

        Date now = new Date();
        gc = new GregorianCalendar();
        gc.setTime(now);
        SpinnerDateModel dateModel = new SpinnerDateModel(now, null, null,
                Calendar.SECOND);
        sp = new JSpinner(dateModel);
        JSpinner.DateEditor editor = new JSpinner.DateEditor(sp, "HH小时mm分ss秒");
        sp.setEditor(editor);
        add(sp);
        b = new JButton("倒计时");
        add(b);
        b.addActionListener(new ActionListener()
        {

            public void actionPerformed(ActionEvent e)
            {
                Thread t = new Thread(new Runnable()
                {

                    public void run()
                    {
                        try
                        {
                            long t1 = System.currentTimeMillis();
                            long t2 = System.currentTimeMillis();
                            while (time)
                            {

                                sp.setValue(sp.getPreviousValue());
                                Thread.sleep(1000);

                            }
                        }
                        catch (InterruptedException e)
                        {
                            e.printStackTrace();
                        }

                    }

                });
                t.start();
            }

        });

    }

}


我想请问下，怎么让这个定时器在00：00：00时停下啊！谢谢了···