Drop&Drag problem

Question

Hi ,everyone:
I want to drag one jtree node to one jtable cell.The tree's node I added my own class: "TreeBranch".
DefaultMutableTreeNode node=new DefaultMutableTreeNode(TreeBranch);The proplem is when I drag a tree node ,I find the "TreeBranch" class in the "(DefaultMutableTreeNode) path.getLastPathComponent()" and the variable "transferable" before the process: "source.startDrag(dge,DragSource.DefaultCopyDrop,transferable,this);"in the TreeDragSource.java .But when in the TableDropTarget.java,I accept the Transferable object ,the TreeNode's userObject is null if the node is my own class TreeBranch .If the node 's userObject is a string ,that was retained.
The variable "transferable" is the TransferableTreeNode's object.The class TransferableTreeNode implements Transferable.And The class TransferableTreeNode is:
// TransferableTreeNode.java
// A Transferable TreePath to be used with Drag & Drop applications.
import java.io.*;
import java.awt.dnd.*;
import java.awt.datatransfer.*;
import javax.swing.tree.*;
import com.clousoft.xbrlview.config.*;
public class TransferableTreeNode implements Transferable {
  public static DataFlavor TREE_PATH_FLAVOR = new DataFlavor(TreePath.class,
                                 "Tree Path");
  DataFlavor flavors[] = { TREE_PATH_FLAVOR };
  TreePath path;
  public TransferableTreeNode(TreePath tp) {
    path = tp;
  public synchronized DataFlavor[] getTransferDataFlavors() {
    return flavors;
  public boolean isDataFlavorSupported(DataFlavor flavor) {
    return (flavor.getRepresentationClass() == TreePath.class);
  public synchronized Object getTransferData(DataFlavor flavor)
    throws UnsupportedFlavorException, IOException {
    if (isDataFlavorSupported(flavor)) {
      return (Object)path;
    } else {
      throw new UnsupportedFlavorException(flavor);
}Who can tell me how to retain my own class type in the tree path when drag and drop.
Thanks !

Answer 1

At a guess, I'd say your data flavour indicates a
serialisable Java object. Thus it will be serialising
your tree node class but your user object probably
isn't serialisable and so doesn't survive the
transit.
In fact, DefaultMutableTreeNode quietly ignores
non-serialisable user objects when serialising
itself.
You could make your user object serialisable but that
may lead to unnecessary copying of it. If you want to
maintain a reference to the user object in your tableCan you me tell me the details ,because I touch the
(rather than receiving a copy of it) you should
probably be using a JVM-local object data flavour
instead.
Hope this helps.Excuse me!
Can you tell me the details because I did not know how to do it using a JVM-local object dataflavour or make my user object serialisable .I am a tenderfoot. Thank you .