如何使用BorderLayout创建可移动的JPanel？

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

JFrame frame = new JFrame("可移动的JPanel示例");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(400, 400);

JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());

JPanel movablePanel = new JPanel();
movablePanel.setBackground(Color.BLUE);

movablePanel.addMouseListener(new MouseAdapter() {
    private int xOffset;
    private int yOffset;

    @Override
    public void mousePressed(MouseEvent e) {
        xOffset = e.getX();
        yOffset = e.getY();
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        int x = e.getXOnScreen() - xOffset;
        int y = e.getYOnScreen() - yOffset;
        frame.setLocation(x, y);
    }
});

panel.add(movablePanel, BorderLayout.CENTER);

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