Java SE (Java Platform, Standard Edition)

Dear all friends:
sorry to bother,
I have following code can edit the leaf of the JTree,
But after i edit it, I found what I updated is lost, How can I persist all changes I made to these edited leaves and nodes(not leaf).
ie, to keep all these changes until i update them later.
Foe Example, I change node name from "blue" in Directory of Color to "NewHouse", then after I exit editing, node not return to blue but keep "NewHouse".

thanks

sunny

import java.awt.BorderLayout;
import java.util.EventObject;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeCellEditor;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeNode;

public class EditLeafSample {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Editable Tree");
    JTree tree = new JTree();
    tree.setEditable(true);

    DefaultTreeCellRenderer renderer = (DefaultTreeCellRenderer) tree.getCellRenderer();
    TreeCellEditor editor = new LeafCellEditor(tree, renderer);
    tree.setCellEditor(editor);

    JScrollPane scrollPane = new JScrollPane(tree);
    frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
    frame.setSize(300, 150);
    frame.setVisible(true);
  }
}

class LeafCellEditor extends DefaultTreeCellEditor {

  public LeafCellEditor(JTree tree, DefaultTreeCellRenderer renderer) {
    super(tree, renderer);
  }

  public LeafCellEditor(JTree tree, DefaultTreeCellRenderer renderer,
      TreeCellEditor editor) {
    super(tree, renderer, editor);
  }

  public boolean isCellEditable(EventObject event) {
    // Get initial setting
    boolean returnValue = super.isCellEditable(event);
    // If still possible, check if current tree node is a leaf
    if (returnValue) {
      Object node = tree.getLastSelectedPathComponent();
      if ((node != null) && (node instanceof TreeNode)) {
        TreeNode treeNode = (TreeNode) node;
        returnValue = treeNode.isLeaf();
      }
    }
    return returnValue;
  }
}