JComboBox选择更改侦听器？

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

JComboBox<String> comboBox = new JComboBox<String>();
comboBox.addItem("选项1");
comboBox.addItem("选项2");
comboBox.addItem("选项3");

class MyItemListener implements ItemListener {
    public void itemStateChanged(ItemEvent e) {
        if (e.getStateChange() == ItemEvent.SELECTED) {
            JComboBox<String> combo = (JComboBox<String>) e.getSource();
            String selectedItem = (String) combo.getSelectedItem();
            System.out.println("选中的项目：" + selectedItem);
        }
    }
}

MyItemListener myListener = new MyItemListener();
comboBox.addItemListener(myListener);

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class JComboBoxExample {
    public static void main(String[] args) {
        JFrame frame = new JFrame("JComboBox 示例");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 200);

        JComboBox<String> comboBox = new JComboBox<String>();
        comboBox.addItem("选项1");
        comboBox.addItem("选项2");
        comboBox.addItem("选项3");

        MyItemListener myListener = new MyItemListener();
        comboBox.addItemListener(myListener);

        frame.getContentPane().add(comboBox, BorderLayout.NORTH);
        frame.setVisible(true);
    }

    class MyItemListener implements ItemListener {
        public void itemStateChanged(ItemEvent e) {
            if (e.getStateChange() == ItemEvent.SELECTED) {
                JComboBox<String> combo = (JComboBox<String>) e.getSource();
                String selectedItem = (String) combo.getSelectedItem();
                System.out.println("选中的项目：" + selectedItem);
            }
        }
    }
}