Refreshing a JTree without collapsing

Question

I have a problem. I've seen a few topics on this issue but none helped.
I try to refresh a tree and preserve the same structure (with the expanded nodes) after refreshing it. In order to do that i save all the expanded paths from the tree before refreshing it and trying to expand them again after refreshing (using expandPath() function). During refreshing all the nodes (but the root) are removed, then added again.
Could anyone tell me what am i doing wrong?
Thank you in advance,
Claudia

Answer 1

The nodes class extends DefaultMutableTreeNode, yes. Yes, the equal method is called.
Here is the refresh method of the tree.
  public void refresh() {
    ArrayList expandedPaths = getExpandedPaths();
    ((MyTreeModel)getModel()).refresh(); // this method removes the nodes of the tree and readding them
    expandPaths(expandedPaths);
  public ArrayList getExpandedPaths() {
    ArrayList expandedPaths = new ArrayList();
    Enumeration enum = getExpandedDescendants(getPathForRow(0));
    while(enum != null && enum.hasMoreElements()) {
      TreePath tp = (TreePath)enum.nextElement();
      expandedPaths.add(tp);
    return expandedPaths;
  public void expandPaths(ArrayList pathlist) {
    for(int i = 0; i < pathlist.size(); i++) {
      expandPath((TreePath)pathlist.get(i));
  }