以下是引用心无旁骛在2010-3-7 00:08:17的发言:
时分秒计时呢

 import java.util.*;
import java.awt.*;
import javax.swing.*;
public class Date2010_1 extends JFrame implements Runnable{
    
    private JLabel lbl;
    private GregorianCalendar g;
    private GregorianCalendar f;
    private long dMillis;
    private long dDay;
    private long dHour;
    private long dMin;
    private long dSec;
    
    public Date2010_1() {
        this.setLayout(null);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setBounds(200, 200, 800, 100);
        lbl = new JLabel();
        lbl.setBounds(0,0,800,100);
        lbl.setFont(new Font(null, Font.BOLD, 30));
        lbl.setForeground(Color.red);
        this.add(lbl);
        this.setTitle("2012");
        this.setVisible(true);
    }
   
  public void run() {
      while(true) {
          try {
          g = new GregorianCalendar();  
        f = new GregorianCalendar(2012, Calendar.DECEMBER, 21,0,0,0);    
        dMillis = f.getTimeInMillis() - g.getTimeInMillis();
        dDay = dMillis/(24*60*60*1000);
        dHour = 24 - g.get(Calendar.HOUR_OF_DAY);
        dMin = 60 - g.get(Calendar.MINUTE) ;
        dSec = 60 - g.get(Calendar.SECOND) ;
        String str = "今天距离2012年12月21日还有"+dDay+"日" + dHour + "小时" +dMin +"分钟" + dSec + "秒";
        lbl.setText(str);
   
        Thread.sleep(1000);
        } catch (Exception ex) {
        }
      }
  }
    
    public static void main(String[] args) {
        Date2010_1 date2010 = new Date2010_1();
        Thread th = new Thread(date2010);
        th.start();
    }
}