Displayed DOM on an tree, then how to modify the tree

Question

Hi,
This my first time here.
I have DOM object parsed from xml. I displayed it on a tree using following 2 classes. My question is how do I reload the treeModelAdapter when I update/insert the tree node? How do I implement valueForPathChanged(...) method? My tree didn't updated using the method.
Note the methods in DefaultTreeModel do not work here.
public class DomToTreeModelAdapter implements TreeModel{
Element element;
public DomToTreeModelAdapter(Element elem) {
element = elem;
public Object getRoot() {
return new AdapterNode(element);
public void valueForPathChanged(TreePath path, Object newValue) {
AdapterNode adapter = new AdapterNode(element);
Object currentNode = path.getLastPathComponent();
Object parentNode = path.getPathComponent(path.getPathCount()-2);
int[] index = {getIndexOfChild(parentNode, currentNode)};
Object[] children = {(Object)newValue};
TreeModelEvent ev = new TreeModelEvent(adapter, path, index, children);
fireTreeNodesChanged( ev);
private Vector listenerList = new Vector();
public void addTreeModelListener( TreeModelListener listener ) {
if ( listener != null && ! listenerList.contains( listener ) ) {
listenerList.addElement( listener );
public void removeTreeModelListener( TreeModelListener listener ) {
if ( listener != null ) {
listenerList.removeElement( listener );
public void fireTreeNodesChanged( TreeModelEvent e ) {
Enumeration listeners = listenerList.elements();
while ( listeners.hasMoreElements() ) {
TreeModelListener listener = (TreeModelListener) listeners.nextElement();
listener.treeNodesChanged( e );
public class AdapterNode {
Node domNode;
public AdapterNode(Node node) { 
domNode = node;
public String toString() { ...
public AdapterNode child(int searchIndex) {
org.w3c.dom.Node node = domNode.getChildNodes().item(searchIndex);
int elementNodeIndex = 0;
for (int i=0; i<domNode.getChildNodes().getLength(); i++) {
node = domNode.getChildNodes().item(i);
if (node.getNodeType() == ELEMENT_TYPE )
&& elementNodeIndex++ == searchIndex) {
break;
return new AdapterNode(node);
public int index(AdapterNode child) {
int count = childCount();
for (int i=0; i<count; i++) {
AdapterNode n = this.child(i);
if (child.toString().equalsIgnoreCase(n.toString())) { return i; }
return -1; // Should never get here.
I also added listener class:
public class DomTreeModelListener implements TreeModelListener {
     Element element;
     public DomTreeModelListener(Element elem){
          element = elem;
     public void treeNodesChanged(TreeModelEvent e) {
          //DefaultMutableTreeNode node;
Object node = e.getTreePath().getLastPathComponent();
System.out.println("node: " + node);
try {
int index = e.getChildIndices()[0];
System.out.println("index: " + index);
//node = node.getChildAt(index);
node = new DomToTreeModelAdapter(element).getChild(node, index);
} catch (NullPointerException exc) {}
What is the problem?
Thank you in advance for any help.

Answer 1

I ment give us a runnable code that demenstrates your problem, try and duplicate it... Dont post use a 5000line class, just one that shows the problem,
ie create a new class that just does what your one is supose to with out all the bits and pieces, if if works then work from there, else post that code.
ps did you also read the code formating tags