如何在jTextPane中换行文本？

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

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

        JTextPane textPane = new JTextPane();
        textPane.setEditable(false);

        StyledDocument doc = textPane.getStyledDocument();

        Style style = doc.addStyle("StyleName", null);
        StyleConstants.setFontFamily(style, "Arial");
        StyleConstants.setFontSize(style, 12);
        StyleConstants.setForeground(style, Color.BLACK);

        ParagraphStyle paragraphStyle = doc.addStyle("ParagraphStyle", null);
        StyleConstants.setLineSpacing(paragraphStyle, 1.5f);
        StyleConstants.setFirstLineIndent(paragraphStyle, 20);

        doc.setParagraphAttributes(0, doc.getLength(), paragraphStyle, false);

        try {
            doc.insertString(doc.getLength(), "This is the first line.\n", style);
            doc.insertString(doc.getLength(), "This is the second line.\n", style);
            doc.insertString(doc.getLength(), "This is the third line.\n", style);
        } catch (BadLocationException e) {
            e.printStackTrace();
        }

        JScrollPane scrollPane = new JScrollPane(textPane);
        frame.getContentPane().add(scrollPane);

        frame.setSize(300, 200);
        frame.setVisible(true);
    }
}