JComboBox takes ages to load/refresh when tried to add more items.

Question

Swing gurus ...
Here is the test app generated from VA3.5 concept is the
same - JComboBox takes long time to add data items to itself when added more items.
In this senario, I tried to load about 500 items into the combo box, takes about 2+ minutes to load. I have an app which needs to show about 1K items in the pick list ( ComboBox ) - which takes any where from 4 - 10 min - this is not acceptable - are there any ways we can load more items into combo box ? Help is really appreciated.
Example:
* Insert the type's description here.
* Creation date: (6/28/2001 11:23:26 AM)
* @author: Administrator
public class ComboTest extends javax.swing.JFrame {
     private javax.swing.JPanel ivjJFrameContentPane = null;
     private javax.swing.JButton ivjLoadBtn = null;
     private javax.swing.JComboBox ivjTestCombo = null;
* ComboTest constructor comment.
public ComboTest() {
     super();
     initialize();
* ComboTest constructor comment.
* @param title java.lang.String
public ComboTest(String title) {
     super(title);
* connEtoC1: (LoadBtn.action.actionPerformed(java.awt.event.ActionEvent) --> ComboTest.loadBtn_ActionPerformed(Ljava.awt.event.ActionEvent;)V)
* @param arg1 java.awt.event.ActionEvent
/* WARNING: THIS METHOD WILL BE REGENERATED. */
private void connEtoC1(java.awt.event.ActionEvent arg1) {
     try {
          // user code begin {1}
          // user code end
          this.loadBtn_ActionPerformed(arg1);
          // user code begin {2}
          // user code end
     } catch (java.lang.Throwable ivjExc) {
          // user code begin {3}
          // user code end
          handleException(ivjExc);
* Return the JFrameContentPane property value.
* @return javax.swing.JPanel
/* WARNING: THIS METHOD WILL BE REGENERATED. */
private javax.swing.JPanel getJFrameContentPane() {
     if (ivjJFrameContentPane == null) {
          try {
               ivjJFrameContentPane = new javax.swing.JPanel();
               ivjJFrameContentPane.setName("JFrameContentPane");
               ivjJFrameContentPane.setLayout(null);
               getJFrameContentPane().add(getTestCombo(), getTestCombo().getName());
               getJFrameContentPane().add(getLoadBtn(), getLoadBtn().getName());
               // user code begin {1}
               // user code end
          } catch (java.lang.Throwable ivjExc) {
               // user code begin {2}
               // user code end
               handleException(ivjExc);
     return ivjJFrameContentPane;
* Return the LoadBtn property value.
* @return javax.swing.JButton
/* WARNING: THIS METHOD WILL BE REGENERATED. */
private javax.swing.JButton getLoadBtn() {
     if (ivjLoadBtn == null) {
          try {
               ivjLoadBtn = new javax.swing.JButton();
               ivjLoadBtn.setName("LoadBtn");
               ivjLoadBtn.setText("Load");
               ivjLoadBtn.setBounds(248, 41, 85, 25);
               // user code begin {1}
               // user code end
          } catch (java.lang.Throwable ivjExc) {
               // user code begin {2}
               // user code end
               handleException(ivjExc);
     return ivjLoadBtn;
* Return the TestCombo property value.
* @return javax.swing.JComboBox
/* WARNING: THIS METHOD WILL BE REGENERATED. */
private javax.swing.JComboBox getTestCombo() {
     if (ivjTestCombo == null) {
          try {
               ivjTestCombo = new javax.swing.JComboBox();
               ivjTestCombo.setName("TestCombo");
               ivjTestCombo.setDoubleBuffered(true);
               ivjTestCombo.setBounds(78, 41, 164, 23);
               // user code begin {1}
               // user code end
          } catch (java.lang.Throwable ivjExc) {
               // user code begin {2}
               // user code end
               handleException(ivjExc);
     return ivjTestCombo;
* Called whenever the part throws an exception.
* @param exception java.lang.Throwable
private void handleException(java.lang.Throwable exception) {
     /* Uncomment the following lines to print uncaught exceptions to stdout */
     // System.out.println("--------- UNCAUGHT EXCEPTION ---------");
     // exception.printStackTrace(System.out);
* Initializes connections
* @exception java.lang.Exception The exception description.
/* WARNING: THIS METHOD WILL BE REGENERATED. */
private void initConnections() throws java.lang.Exception {
     // user code begin {1}
     // user code end
     getLoadBtn().addActionListener(new java.awt.event.ActionListener() {
          public void actionPerformed(java.awt.event.ActionEvent e) {
               connEtoC1(e);
* Initialize the class.
/* WARNING: THIS METHOD WILL BE REGENERATED. */
private void initialize() {
     try {
          // user code begin {1}
          // user code end
          setName("ComboTest");
          setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
          setSize(426, 131);
          setTitle("Test App");
          setContentPane(getJFrameContentPane());
          initConnections();
     } catch (java.lang.Throwable ivjExc) {
          handleException(ivjExc);
     // user code begin {2}
     // user code end
* Comment
public void loadBtn_ActionPerformed(java.awt.event.ActionEvent actionEvent)
     String val = "String Item: ";
     for ( int i=0; i<500; i++ )
          getTestCombo().addItem( val + i);
     return;
* main entrypoint - starts the part when it is run as an application
* @param args java.lang.String[]
public static void main(java.lang.String[] args) {
     try {
          ComboTest aComboTest;
          aComboTest = new ComboTest();
          aComboTest.addWindowListener(new java.awt.event.WindowAdapter() {
               public void windowClosing(java.awt.event.WindowEvent e) {
                    System.exit(0);
          aComboTest.show();
          java.awt.Insets insets = aComboTest.getInsets();
          aComboTest.setSize(aComboTest.getWidth() + insets.left + insets.right, aComboTest.getHeight() + insets.top + insets.bottom);
          aComboTest.setVisible(true);
     } catch (Throwable exception) {
          System.err.println("Exception occurred in main() of javax.swing.JFrame");
          exception.printStackTrace(System.out);

Answer 1

The "Really fast combo boxes" thread referred to by lk555 can be summarized as follows:
1. RegFish wrote a custom JComboBox that handles large numbers of elements better than a standard JComboBox does.
2. You can download his code at http://www.reddfish.co.nz/freesoftware/PoliteComboBox.jar
3. You may want to reconsider your design, since a JComboBox with more than a few dozen elements is usually too hard for the user to use (see various postings in the long thread).