// import javax.swing.tree.*;
    // import java.io.*;
    DefaultTreeModel model;
    DefaultMutableTreeNode root;
 
    private void showBranch (DefaultMutableTreeNode above, 
                             File dir, int level)
    {
       File [] files = dir.listFiles();
       if (files != null)
          for (File f : files)
          {
             DefaultMutableTreeNode node;
             node = new DefaultMutableTreeNode (f.getName());
             above.add (node);
             if (level > 1 && f.isDirectory())
                 showBranch (node, f, level-1);
           }
    }
    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
       File dir = new File ("c:\\");
       root = new DefaultMutableTreeNode (dir.getPath());
       showBranch (root, dir, 2);
 
       model = new DefaultTreeModel (root); 
       jTree1.setModel (model);
    }                                        
 
    private void jTree1ValueChanged(javax.swing.event.TreeSelectionEvent evt) {                                    
       TreePath path = evt.getPath();
       Object obj = path.getLastPathComponent();
       jTextField1.setText ("selected " + obj.getClass() + " : " + obj);
    }                                   
 
    private void jTree1TreeExpanded(javax.swing.event.TreeExpansionEvent evt) {                                    
       TreePath path = evt.getPath();
       Object obj = path.getLastPathComponent();
       jTextField1.setText ("expanded " + obj.getClass() + " : " + obj);
    }