DnD with JTree

Question

Hi All,
I am creating two JTree ojects and registering it for DnD by calling method setDragEnabled(true). I created Class that extends from TransferHandler which contains all the required method including importData(). I have also created class for Transferable. But when i try to perform drag from one tree and drop it on another tree it is not working, but if I do it on the same tree it is working fine which I don't want to do. Here are the code snippets that create tree object and initialization.
JPanel panel = new JPanel();
JTree onTree = new JTree(new Vector());
onTree.setCellRenderer(new MyTreeCellRenderer());
onTree.setShowsRootHandles(true);
transferHandler1 = new MyTransferHandler();
onTree.setTransferHandler(transferHandler1);
onTree.setDragEnabled(true);
MyObjectJB myObj = (MyObjectJB) createData();
AdPlanningTreeNode root = new AdPlanningTreeNode(spot);
AdPlanningTreeNode spotNode = constructSubTree(root, spot);
JTree offTree = new JTree(root);
offTree.setCellRenderer(new DisplayTreeCellRenderer());
offTree.setShowsRootHandles(true);
transferHandler2 = new DisplayTransferHandler();
offTree.setTransferHandler(transferHandler2);
offTree.setDragEnabled(true);
AdPlanningJScrollPane offScroller = new AdPlanningJScrollPane(offTree);
AdPlanningJScrollPane onScroller = new AdPlanningJScrollPane(onTree);
panel.add(offScroller);
panel.add(onScroller);Here is code in importData() method of MyTransferHandler.
public boolean importData(JComponent comp, Transferable t) {
boolean isImported = false;
try {
     if (!canImport(comp, t.getTransferDataFlavors())) {
          System.out.println("MyTransferHandler.importData ; can not import");
          return false;
     JTree targetTree = (JTree) comp;
     TreePath parentPath = targetTree.getSelectionPath();
     MyTreeNode parentNode = null;
     DefaultTreeModel model = (DefaultTreeModel) targetTree.getModel();
     MyObject item = (MyObject) DeepCopyUtil.createDeepCopy(t.getTransferData(SUPPORTED_FLAVORS));
     MyTreeNode node = new MyTreeNode((MyObjectJB) item);
     if (parentPath == null) {
          model.setRoot(node);
          targetTree.setSelectionRow(0);
          targetTree.repaint();
     else {
          parentNode = (MyTreeNode) parentPath.getLastPathComponent();
          model.insertNodeInto(node, parentNode, 0);
     isImported = true;
catch (UnsupportedFlavorException e) {
     e.printStackTrace();
     return false;
catch (IOException e) {
     e.printStackTrace();
     return false;
catch (Exception e) {
     e.printStackTrace();
     return false;
System.out.println("DisplayTransferHandler.importData completed");
return isImported;
One important thing is after dragging and importData method calls
model.setRoot(node), then model is showing change in data but not reflected in Tree.

Answer 1

Following link may help you understand: http://forums.java.net/jive/thread.jspa?threadID=9196