Re: JComboBox with DefaultComboBoxModel doesn't allow to add or remove

Knute Johnson <>
Thu, 22 Nov 2012 10:37:42 -0800
On 11/22/2012 4:03 AM, Rotariu Mihai wrote:

I updated my post on another java forum where I have a very simple
example why is not working. If you have the time and the patience
please check

That doesn't really cut it as an SSCCE because it doesn't compile. But
I was intrigued enough to write one for you.

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

public class test extends JPanel {
     static final String[] items = {
"one","two","three","four","five","six" };

     private final Vector<String> vector = new Vector<>();
     private final JComboBox<String> box;

     public test() {
         box = new JComboBox<String>(vector);
         for (String item: items)
         box.addActionListener(new ActionListener() {
             public void actionPerformed(ActionEvent ae) {
                 String item = (String)box.getSelectedItem();
                 // if item is not in list and item is not empty
                 if (!vector.contains(item) && !item.equals("")) {
                     // attempt to blank entry field
                     Component c = box.getEditor().getEditorComponent();
                     if (c instanceof JTextComponent)

         JButton rem = new JButton("Remove All");
         rem.addActionListener(new ActionListener() {
             public void actionPerformed(ActionEvent ae) {
                 Component c = box.getEditor().getEditorComponent();
                 if (c instanceof JTextComponent)


     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 JFrame f = new JFrame("test");
                 test t = new test();


Knute Johnson

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