Секундомер

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.TimerTask;

public class InputPanel extends JFrame{
	private JPanel panel = new JPanel(new GridLayout(1, 1, 1, 1));
	public TimerLabel tl = new TimerLabel();
	public InputPanel(){
		final JFrame f = new JFrame();
		final JPanel contentPane = new JPanel();
		contentPane.add(new JLabel("Запустить секундомер?", JLabel.CENTER));
		contentPane.add(new JButton(new AbstractAction("Запустить"){
			public void actionPerformed(ActionEvent e){
				setContentPane(new BPanel());
				setSize(500, 340);
				Container container = getContentPane();
				// setLocationRelativeTo(null);             -      окно по центру экрана

				JButton button1 = new JButton("Stop");
				panel.add(button1);
				ActionListener actionListener = new TestActionListener();
				button1.addActionListener(actionListener);
				JButton button = new JButton("Запустить с начала");
				panel.add(button);
				ActionListener actionListene = new Test();
				button.addActionListener(actionListene);
				setResizable(false);// окно не меняет размер
				panel.setBackground(Color.BLACK);
				container.add(panel);
				panel.add(tl);
				panel.setAlignmentX(JLabel.RIGHT_ALIGNMENT);
				Font font = new Font("Verdana", Font.PLAIN, 32);
				tl.setFont(font);
				tl.setForeground(Color.WHITE);
				f.setVisible(false);
				setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
			}
		}));
		contentPane.add(new JButton(new AbstractAction("Выход"){
			public void actionPerformed(ActionEvent e)
				System.exit(0);
		}));

		f.setContentPane(contentPane);
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		SwingUtilities.invokeLater(new Runnable(){
			public void run(){
				f.pack();
				f.show();
			}
		});
	}
	class TimerLabel extends JLabel{
		public java.util.Timer timer = new java.util.Timer();
		public TimerLabel()
			timer.scheduleAtFixedRate(timerTask, 0, 1000);
		public TimerTask timerTask = new TimerTask(){
			private volatile int time = -1;
			private Runnable refresher = new Runnable(){
				public void run(){
					int t = time;
					DecimalFormat decimalFormat = new DecimalFormat("00"); // задаем формат вывода секундомера
					TimerLabel.this.setText(decimalFormat.format(t / 60) + ":" + decimalFormat.format(t % 60));
				}
			};
			public void run(){
				time++;
				SwingUtilities.invokeLater(refresher);
			}

		};
		public void StopTimer()
			timer.cancel();
	}
	public static void main(String[] args) throws InterruptedException{
		JFrame app = new InputPanel();
		app.setVisible(true);
	}
	public class TestActionListener implements ActionListener{
		public void actionPerformed(ActionEvent e)
			tl.StopTimer();
	}
	public class Test implements ActionListener{
		public void actionPerformed(ActionEvent e){
			JFrame app = new InputPanel();
			app.setVisible(true);
		}
	}
}

class BPanel extends JPanel{
	public void paintComponent(Graphics g){
		Image im = null;
		try {
			im = ImageIO.read(new File("q.jpg"));
                }
		catch (IOException e)
		g.drawImage(im, 0, 0, null);
	}
}