如何在JTextPane中设置对齐？

import javax.swing.*;
import javax.swing.text.*;

public class JTextPaneAlignmentExample {
    public static void main(String[] args) {
        JFrame frame = new JFrame("JTextPane Alignment Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JTextPane textPane = new JTextPane();
        textPane.setText("This is a sample text.");
        
        StyledDocument doc = textPane.getStyledDocument();
        Style style = doc.addStyle("alignStyle", null);
        StyleConstants.setAlignment(style, StyleConstants.ALIGN_CENTER);
        doc.setParagraphAttributes(0, doc.getLength(), style, false);

        frame.getContentPane().add(new JScrollPane(textPane));
        frame.setSize(300, 200);
        frame.setVisible(true);
    }
}