Java Swing - 如何在JFrame上使用Timer创建计数器

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

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

public class Main {

  public static void main(String[] args) {
    new Main();
  }

  public Main() {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLayout(new BorderLayout());
    frame.add(new TestPane());
    frame.pack();
    frame.setVisible(true);
  }
}

class TestPane extends JPanel {
  JLabel label;
  Timer timer;
  int count;
  public TestPane() {
    label = new JLabel("...");
    setLayout(new GridBagLayout());
    add(label);
    timer = new Timer(500, new ActionListener() {
      @Override
      public void actionPerformed(ActionEvent e) {
        count++;
        if (count < 100000) {
          label.setText(Integer.toString(count));
        } else {
          ((Timer) (e.getSource())).stop();
        }
      }
    });
    timer.setInitialDelay(0);
    timer.start();
  }
  @Override
  public Dimension getPreferredSize() {
    return new Dimension(200, 200);
  }
}