在系统中添加或删除文件后更新JTree

Question

我有一个JTree在C盘上显示和传输目录和文件。在这个JTree中，用户可以通过拖放来改变文件的位置。我已经实现了TransferHandler类来处理DefaultMutableTreeNode的传输，同时将文件从一个位置传输到另一个位置。从我第一次拖放文件就可以了（该文件的defaultMutableTreeNode被删除，并创建了新的defaultMutableTreeNode，此文件也在磁盘上传输）。但问题是我第二次这样做。 JTree在更改后不会更新，我无法拖放defaultMutableTreeNode。

我呼叫所有可能的更新功能，例如updateUI，他们没有工作。我花了三天时间，我不知道该怎么做。 我从类扩展TransferHandler中粘贴了两个函数。我认为jtree应该在这个函数中更新。任何人都可以看看它并告诉我何时更新这棵树以及如何？

//bundle up selected files into one list and export it
protected Transferable createTransferable(JComponent c) {
   DefaultMutableTreeNode tmpNode;
   JTree node = (JTree)c;
   TreePath[] treePaths = node.getSelectionPaths();
   if(treePaths != null) {
      ArrayList<DefaultMutableTreeNode> nodesToCopy = new ArrayList<DefaultMutableTreeNode>();
      fileToCopy = new ArrayList<File>();
      ArrayList<DefaultMutableTreeNode> nodesToRemove = new ArrayList<DefaultMutableTreeNode>();
      fileToRemove = new ArrayList<File>();
      DefaultMutableTreeNode topNode = (DefaultMutableTreeNode)treePaths[0].getLastPathComponent();
    //  File dir = (File)topNode.getUserObject();
      for(int i=0; i<treePaths.length; i++) {
          DefaultMutableTreeNode currentNode = 
                  (DefaultMutableTreeNode)treePaths[i].getLastPathComponent();
          File file = (File)currentNode.getUserObject();
          if(currentNode.getLevel() < topNode.getLevel()) 
              break;
          if (file.isDirectory()) {
              tmpNode = FileNodeTree.createNodes(null,file);
              nodesToCopy.add(tmpNode);
              fileToCopy.add(file);
              fileToRemove.add(file);
              nodesToRemove.add(currentNode);
          } else {    
              nodesToCopy.add(copyToNode(file));
              fileToCopy.add(file);
              nodesToRemove.add(currentNode);
              fileToRemove.add(file);
          }
      }
      DefaultMutableTreeNode[] nodes = nodesToCopy.toArray(
              new DefaultMutableTreeNode[nodesToCopy.size()]);
      removeNodes = nodesToRemove.toArray(
              new DefaultMutableTreeNode[nodesToRemove.size()]);
      return new FilesTransferable(nodes);
   }
   return null;
}

private DefaultMutableTreeNode copyToNode(File node) {
    return new DefaultMutableTreeNode(node);
}


public boolean importData(TransferHandler.TransferSupport support) {
   DefaultMutableTreeNode[] nodes = null;
   if(!canImport(support))
       return false;

   try {
      nodes = (DefaultMutableTreeNode[]) support.getTransferable().getTransferData(fileFlavor);
      for(DefaultMutableTreeNode nodess : nodes)
          System.out.println("nodess: "+nodess);
   } catch (IOException e) {
       throw new RuntimeException(e);
   } catch (UnsupportedFlavorException e1) {
       System.err.println("UnsupportedFlavorException: "+e1.getMessage());
   }

   //fetch the drop location, path & childIndex
   JTree.DropLocation dropLoc = (JTree.DropLocation)support.getDropLocation();
   TreePath path = dropLoc.getPath();

   int childIndex = dropLoc.getChildIndex();

   //create new nodes and insert it into JTree
   DefaultMutableTreeNode parent = (DefaultMutableTreeNode) path.getLastPathComponent();
   File top = (File)parent.getUserObject();
   JTree tree = (JTree)support.getComponent();

   DefaultTreeModel model = (DefaultTreeModel) tree.getModel();
   //configure for dropMode
   int index = childIndex;   //for dropMode.INSERT
   if(childIndex == -1)     //for dropMode.ON
       index = parent.getChildCount();
  //insert data into JTree
   for(int i=0; i<nodes.length; i++) 
       model.insertNodeInto(nodes[i], parent, index++);
   try {
        for(File file : fileToCopy) {
            if(file.isDirectory()) {
                FileUtils.copyDirectory(file, new File(top+"/"+file.getName()));

            } else {
            Files.copy(file.toPath(), 
                    (new File(top+"/"+file.getName()).toPath()), StandardCopyOption.REPLACE_EXISTING);
            }
        }
   } catch (IOException e) {
           System.err.println("Cannot copy to other directory " + e.getMessage());
           }
   return true;