用JComboBox实现三级联动

刚刚用JComboBox实现了一个三级联动菜单

 

1. import java.awt.event.ActionEvent;
2. import java.awt.event.ActionListener;
3. import javax.swing.DefaultComboBoxModel;
4. import javax.swing.JComboBox;
5. import javax.swing.JFrame;
6. import javax.swing.JPanel;
8. public class ComboBoxDemo extends JFrame {
10.     private DefaultComboBoxModel model = new DefaultComboBoxModel();
11.     private DefaultComboBoxModel model1 = new DefaultComboBoxModel();
12.     private DefaultComboBoxModel model2 = new DefaultComboBoxModel();
14.     private JComboBox firstComboBox;
15.     private JComboBox secondComboBox;
16.     private JComboBox thirdComboBox;
18.     private String[] first = { "001", "002", "003" };
20.     private String[] second_first = { "00101", "00102", "00103" };
21.     private String[] second_second = { "00201", "00202", "00203" };
22.     private String[] second_third = { "00301", "00302", "00303" };
24.     private String[] third_first_first = { "0010101", "0010102", "0010103" };
25.     private String[] third_second_first = { "0010201", "0010202", "0010203" };
26.     private String[] third_third_first = { "0010301", "0010302", "0010303" };
27.     private String[] third_second_second = { "0020101", "0020102", "0020103" };
28.     private String[] third_first_second = { "0020201", "0020202", "0020203" };
29.     private String[] third_third_second = { "0020301", "0020302", "0020303" };
30.     private String[] third_first_third = { "0030101", "0030102", "0030103" };
31.     private String[] third_second_third = { "0030201", "0030202", "0030203" };
32.     private String[] third_third_third = { "0030301", "0030302", "0030303" };
34.     public ComboBoxDemo() {
35.         setTitle("ComboBoxTest");
36.         setSize(300, 200);
37.         setDefaultCloseOperation(EXIT_ON_CLOSE);
38.         for (int i = 0, n = first.length; i < n; i++) {
39.             model.addElement(first[i]);
40.         }
41.         firstComboBox = new JComboBox(model);
42.         firstComboBox.addActionListener(new ActionListener() {
43.             public void actionPerformed(ActionEvent evt) {
44.                 JComboBox source = (JComboBox) evt.getSource();
45.                 String item = (String) source.getSelectedItem();
46.                 try {
47.                     if (item.equals("001")) {
48.                   &