所见所得(WYSIWYG ) 编辑器问题?

我只想实现 Bullets (ordered list & unordered list)
高手们可以帮我修正吗?import java.awt.*;
import javax.swing.*;
import javax.swing.text.html.*;public class BasicEditor extends JFrame {    private JTextPane editor;    public BasicEditor() {        try {
            JPanel buttonPanel = new JPanel();            editor = new JTextPane();
            editor.setContentType("text/html");            JButton bulletButton = new JButton("Bullets");
            String INSERT_UL_HTML = "<ul><li></li></ul>";
            HTMLEditorKit.InsertHTMLTextAction bulletAction = new HTMLEditorKit.InsertHTMLTextAction("Bullets", INSERT_UL_HTML,
                    HTML.Tag.UL, HTML.Tag.LI,
                    HTML.Tag.BODY, HTML.Tag.UL);
            bulletButton.setAction(bulletAction);
            buttonPanel.setLayout(new FlowLayout());
            buttonPanel.add(bulletButton);            JScrollPane scrollPane = new JScrollPane(editor);
            scrollPane.setPreferredSize(new Dimension(getSize().width * 7 / 8, getSize().height * 5 / 8));            getContentPane().add(buttonPanel, BorderLayout.NORTH);
            getContentPane().add(scrollPane, BorderLayout.CENTER);
            setSize(600, 500);
            setDefaultCloseOperation(EXIT_ON_CLOSE);
        } catch (Exception e) {
            e.printStackTrace();
        }    }    public static void main(String[] args) {
        BasicEditorApplet bea = new BasicEditorApplet();
        bea.setVisible(true);
    }
}