如何在调整浏览器大小时调整Java小程序的大小？

import javax.swing.*;
import java.awt.*;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;

public class ResizableJavaApp {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Resizable Java App");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 300);
        frame.setResizable(true);

        JPanel panel = new JPanel();
        panel.setLayout(new BoxLayout(panel, BoxLayout.Y_AXIS));
        JLabel label1 = new JLabel("Label 1");
        JLabel label2 = new JLabel("Label 2");
        panel.add(label1);
        panel.add(label2);

        frame.add(panel);
        frame.setVisible(true);

        frame.addComponentListener(new ComponentAdapter() {
            @Override
            public void componentResized(ComponentEvent e) {
                int width = frame.getWidth();
                int height = frame.getHeight();
                panel.setPreferredSize(new Dimension(width, height));
                frame.pack();
            }
        });
    }
}