如何使用默认JButton居中JPanel中的FlowLayout？

import javax.swing.*;
import java.awt.*;

public class MainFrame extends JFrame {

    public MainFrame() {
        setTitle("JButton居中示例");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        // 创建JPanel并设置布局管理器为FlowLayout
        JPanel panel = new JPanel(new FlowLayout(FlowLayout.CENTER));
        
        // 创建JButton并添加到JPanel中
        JButton button = new JButton("按钮");
        panel.add(button);
        
        // 将JPanel添加到主容器中
        add(panel);
        
        pack();
        setLocationRelativeTo(null);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new MainFrame().setVisible(true);
            }
        });
    }
}