java 时间现格式为00:00:00开始计时，如何表示

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

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

public class Test extends JFrame{

JLabel lbl=new JLabel();
Date now=new Date();
public Test() {

now.setHours(0);
now.setMinutes(0);
now.setSeconds(0);

Timer timer=new Timer(1000,new ActionListener(){

public void actionPerformed(ActionEvent e) {

Date now2=new Date(now.getTime()+1000);
now=now2;
SimpleDateFormat formatter = new SimpleDateFormat("HH:mm:ss");

lbl.setText(formatter.format(now));
}

});
timer.start();

this.setLayout(new FlowLayout());
this.add(lbl);

this.setSize(300,200);