ValueChanged- and keyReleased-Events in JTree

Question

Hello,
Suppose I have Items in a JTree. Any time the selected item changes, heavy work has to be done to get the details of the node and present it to the user.
Suppose further the user uses the arrow-keys to scroll through the list an he holds down the key. I do get many calls to my Listeners valueChanged(TreeSelectionEvent event), but I am interested just in the last event, in order to avoid all the heavy work. How can this be done?
I tried the following, but I do get a keyReleased-Event at any new selection. (Maybe because a nested component of the JTree feels like I had released the arrow-key. Is this a bug?):
private class NodeSelectionEventHandler implements KeyListener, TreeSelectionListener {
private boolean forwardEvents = true;
private EventObject lastEvent;
public void keyTyped(KeyEvent e) {
public void keyPressed(KeyEvent e) {
forwardEvents = false;
public void keyReleased(KeyEvent e) {
//System.out.println(e.getComponent());
// Leider bekomme ich nach jeder auswahl mit Cursortaste auch einen
// keyReleased-Event, obwohl die Taste immer noch gedrueckt ist.
forwardEvents = true;
if (lastEvent != null) {
lastEvent = null;
fireNodeSelectionChanged();
//System.out.println("Last Selection forwarded");
public void valueChanged(TreeSelectionEvent event) {
// there is no event.getValueIsAdjusting() in JDK1.3
handelEvent(event);
private void handelEvent(EventObject event) {
//Thread.dumpStack();
if (forwardEvents) {
lastEvent = null;
fireNodeSelectionChanged();
//System.out.println("Selection forwarded");
else {
lastEvent = event;
//System.out.println("Selection eaten");

Answer 1

I have a JTree from which I generate classes on selection.
To ensure only one event is fired I install two listeners.
I install a mouse listener and capture an event when the mouse is clicked, and I install a key listener and only catch the enter key being pressed as follows:
tree.addMouseListener(new java.awt.event.MouseAdapter() {
          public void mouseClicked(MouseEvent e) {
          showFunction();
tree.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyReleased(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_ENTER) {
showFunction();
This means something happens only if a user clicks on the node with the mouse or selects the node and presses the enter button. I have used this as a general standard throughout my application and it works on all platforms.
Hope this helps