Once again, File Tree refreshing

Question

Ok, so I created my own implementation of a JTree to display a file system. Works fine and everything, but I want it to update in a regular interval.
Right now my own model extends TreeModel and I put a class containing the file object as custom data in DefaultMutableTree objects.
Now I tried all kinds of things like reload(), nodeStructureChanged() and similar stuff, but I can't get it to update.
Here's my current code:
FileTreeModel:
public class FileTreeModel extends DefaultTreeModel {
    private ArrayList treeModelListeners = new ArrayList();
    private DefaultMutableTreeNode rootFile;
    public FileTreeModel(DefaultMutableTreeNode root) {
         super(root);
        rootFile= root;
//////////////// Fire events //////////////////////////////////////////////
     * The only event raised by this model is TreeStructureChanged with the
     * root as path, i.e. the whole tree has changed.
    protected void fireTreeStructureChanged(DefaultMutableTreeNode oldRoot) {
        int len = treeModelListeners.size();
        TreeModelEvent e = new TreeModelEvent(this,
                                              new Object[] {oldRoot});
        for (int i = 0; i < len; i++) {
            ((TreeModelListener)treeModelListeners.get(i)).
                    treeStructureChanged(e);
//////////////// TreeModel interface implementation ///////////////////////
     * Adds a listener for the TreeModelEvent posted after the tree changes.
    @SuppressWarnings("unchecked")
     public void addTreeModelListener(TreeModelListener l) {
        treeModelListeners.add(l);
     * Returns the child of parent at index index in the parent's child array.
    public Object getChild(Object parent, int index) {
         if(((DefaultMutableTreeNode)parent).getUserObject() instanceof String){
               return ((DefaultMutableTreeNode)parent).getChildAt(index);
         FileNode[] files=getOrderedList((FileNode)((DefaultMutableTreeNode)parent).getUserObject());
         if(files.length>index){
               return new DefaultMutableTreeNode(files[index]);
          return null;
     public int getChildCount(Object parent) {
          //if root
          if(((DefaultMutableTreeNode)parent).getUserObject() instanceof String){
               return ((DefaultMutableTreeNode)parent).getChildCount();
          FileNode[] files=getOrderedList((FileNode)((DefaultMutableTreeNode)parent).getUserObject());
          if(files!=null){
               return files.length;
          return 0;               
     public boolean isLeaf(Object FileNode) {
          if(((DefaultMutableTreeNode)FileNode).getUserObject() instanceof String){
               return false;
          }else{
               FileNode f=(FileNode)((DefaultMutableTreeNode)FileNode).getUserObject();
               return f.get().isFile();
     * Returns the index of child in parent.
    public int getIndexOfChild(Object parent, Object child) {
         FileNode[] files=getOrderedList((FileNode)((DefaultMutableTreeNode)parent).getUserObject());
        if(files!=null){
             for(int i=0;i<files.length;i++){
                  if(files.equals((FileNode)((DefaultMutableTreeNode)child).getUserObject())){
               return i;
return -1;
* Returns the root of the tree.
public Object getRoot() {
return rootFile;
* Removes a listener previously added with addTreeModelListener().
public void removeTreeModelListener(TreeModelListener l) {
treeModelListeners.remove(l);
* Messaged when the user has altered the value for the item
* identified by path to newValue. Not used for now.
public void valueForPathChanged(TreePath path, Object newValue) {
System.out.println("*** valueForPathChanged : "
+ path + " --> " + newValue);
//get ordered list, so that dirs appear first
public FileNode[] getOrderedList(FileNode f){
     if(f!=null){
          File[] fc=f.get().listFiles();
          if(fc!=null){
               ArrayList<FileNode> fchildren=new ArrayList<FileNode>();
               //Implementation of manual file filter is required because of special
               //folders, atleast in windows
               for(int i=0;i<fc.length;i++){
                    if(fc[i].isDirectory()){/!fc[i].getName().equals(FileSystemView.getFileSystemView().getSystemDisplayName(fc[i]))){
                         fchildren.add(new FileNode(fc[i]));
                         continue;
               String extension = Utils.getExtension(fc[i]);
          if (extension != null) {
          if (extension.equals(Utils.alb)) {
               fchildren.add(new FileNode(fc[i]));
               FileNode[] fret=new FileNode[fchildren.size()];
               int pos=0;
               for(int i=0;i<fret.length;i++){
                    if(((FileNode)fchildren.get(i)).get().isDirectory()){
                         fret[pos]=((FileNode)fchildren.get(i));
                         pos++;
               for(int i=0;i<fret.length;i++){
                    if(!((FileNode)fchildren.get(i)).get().isDirectory()){
                         fret[pos]=((FileNode)fchildren.get(i));
                         pos++;
               return fret;
     return null;
JFileTree:
public class JFileTree extends JTree {
    public JFileTree() {         
        getSelectionModel().setSelectionMode(
                TreeSelectionModel.SINGLE_TREE_SELECTION);
        DefaultTreeCellRenderer renderer = new DefaultTreeCellRenderer();
        setCellRenderer(renderer);
    }and FileNode:
//slightly modified to return filename instead of path in tostring() to fit into trees
public class FileNode{
     private File f;
     public FileNode(File file) {
          f=file;
     public String toString(){
          return FileSystemView.getFileSystemView().getSystemDisplayName(f);
     public File get() {
          return f;
     public void set(File f) {
          this.f = f;
}I searched quite a bit in these forums but only found places where it said to use reload or one of the functions to insert nodes or so which isn't applicable in the case of a file system.
I could really need some help here, as I have been messing around for quite some time but couldn't get it working properly.
Does anyone know of a complete and proper implemented FileTree? The sun examples act a bit different, and the other examples I could find weren't complete in the aspect of refreshing the contents.
Message was edited by:
Fragman
Message was edited by:
Fragman

Answer 1

I searched quite a bit in these forums...Well you should probably be searching the Swing forums where Swing related questions should be posted.
I don't know much about using JTree, but I see no reason to create a custom TreeModel. Use the DefaultTreeModel. It handles parent/child relationships which is all a directory structure is.
In either case start with a simple example. That is hard code two different tree structures and then have a button to toggle the tree model. Once you understand how that works then you move on a more dynamic structure.
The code you posted doesn't help use since it is not compileable or executable.
If you need further help then you need to create a [url http://homepage1.nifty.com/algafield/sscce.html]Short, Self Contained, Compilable and Executable, Example Program that demonstrates the incorrect behaviour, because I can't guess exactly what you are doing based on the information provided.
And don't forget to use the [url http://forum.java.sun.com/help.jspa?sec=formatting]Code Formatting Tags so the code retains its original formatting.