计时器的实现

[quote]

package org.tarena.day03;

import java.text.SimpleDateFormat;
import java.util.Calendar;

import javax.swing.JFrame;
import javax.swing.JLabel;

public class Test01 extends Thread{

	JFrame jf = new JFrame("计时");
	JLabel jl = new JLabel();

	Test01(){
		jf.add(jl);
	jf.setSize(400, 300);
	jf.setTitle("计时器");
	jf.setVisible(true);
	jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	}

	public void run(){
		int i = 1;
		String date;
		while(i>0){
			date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(Calendar.getInstance().getTime());
			jl.setText(date);
			try {
				Thread.sleep(1000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			if(i > 100){
				i = 1;
			}
			i++;
		}
	}

	public static void main(String[] args) {
		new Test01().start();
	}

}

[/quote]