如何在Java中创建带有unicode图像的JButton？

import javax.swing.*;
import java.awt.*;
import java.awt.geom.Rectangle2D;

public class UnicodeJButtonExample {

    public static void main(String[] args) {
        JFrame frame = new JFrame("Unicode JButton Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        JButton button = createUnicodeButton("\u2605", 24);
        frame.getContentPane().add(button);
        
        frame.pack();
        frame.setVisible(true);
    }
    
    public static JButton createUnicodeButton(String unicode, int fontSize) {
        JButton button = new JButton() {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                Graphics2D g2d = (Graphics2D) g;
                Font font = getFont().deriveFont(Font.PLAIN, fontSize);
                g2d.setFont(font);
                
                FontMetrics fm = g2d.getFontMetrics();
                Rectangle2D textBounds = fm.getStringBounds(unicode, g2d);
                
                int x = (getWidth() - (int) textBounds.getWidth()) / 2;
                int y = (getHeight() - (int) textBounds.getHeight()) / 2 + fm.getAscent();
                
                g2d.drawString(unicode, x, y);
            }
        };
        
        button.setPreferredSize(new Dimension(fontSize, fontSize));
        button.setFocusPainted(false);
        
        return button;
    }
}