How to force JTree to not display the leaves

Question

Hi
Is there anyway to force JTree to not display the "end nodes" so to speak.
What I want is that if a node is a leaf and is not allowed to have children
I do not want the JTree to display them.
I need this to build a component for a custom file system view like Windows Explorer
which contains a tree with folders on the left and and contents of the currently selected( expanded)
folder on the right. But Explorer does not display any files in the left pane, only folders.
So I need to implement the same in my component

Answer 1

This will give you some things to think aboutimport java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.util.*;
public class Test3 extends JFrame {
  Vector nodes = new Vector();
  DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
  DefaultTreeModel dtm = new DefaultTreeModel(root);
  JTree jt = new JTree(dtm);
  JCheckBox jcb = new JCheckBox("Allow Expansion");
  Random r = new Random();
  int nodeCount=0;
  public Test3() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = getContentPane();
    addNodes(root,0);
    content.add(jcb, BorderLayout.NORTH);
    content.add(new JScrollPane(jt), BorderLayout.CENTER);
    jt.addTreeWillExpandListener(new TreeWillExpandListener() {
      public void treeWillCollapse(TreeExpansionEvent tse) {}
      public void treeWillExpand(TreeExpansionEvent tse) throws ExpandVetoException{
        if (jcb.isSelected()) return;
        TreeNode tn = (TreeNode)tse.getPath().getLastPathComponent();
        Enumeration e = tn.children();
        boolean expand = false;
        while (!expand && e.hasMoreElements()) {
          if (((TreeNode)e.nextElement()).getChildCount()!=0) expand  = true;
        if (!expand) throw new ExpandVetoException(tse);
    setSize(400, 400);
  private void addNodes(DefaultMutableTreeNode parent, int level) {
    int cnt = r.nextInt(3)+3-level;
    for (int i=0; i<cnt; i++) {
      DefaultMutableTreeNode node = new DefaultMutableTreeNode("Node"+nodeCount++);
      parent.add(node);
      nodes.add(node);
      addNodes(node, level+1);
  public static void main(String[] args) { new Test3().setVisible(true); }
}