如何获取JPopupMenu选择的项目索引？

import javax.swing.*;
import javax.swing.event.PopupMenuEvent;
import javax.swing.event.PopupMenuListener;

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

        JPopupMenu popupMenu = new JPopupMenu();
        popupMenu.add("Item 1");
        popupMenu.add("Item 2");
        popupMenu.add("Item 3");

        JTextField textField = new JTextField();
        textField.setBounds(50, 50, 150, 30);

        textField.setComponentPopupMenu(popupMenu);

        popupMenu.addPopupMenuListener(new PopupMenuListener() {
            @Override
            public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
            }

            @Override
            public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
                JPopupMenu menu = (JPopupMenu) e.getSource();
                int selectedIndex = menu.getSelectionModel().getSelectedIndex();
                textField.setText("Selected index: " + selectedIndex);
            }

            @Override
            public void popupMenuCanceled(PopupMenuEvent e) {
            }
        });

        frame.add(textField);
        frame.setSize(300, 200);
        frame.setLayout(null);
        frame.setVisible(true);
    }
}