可以给我几个JTree的例子吗

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;

public class TreeEditTest {
public static void main(String[] args) {
JFrame frame = new TreeEditFrame();
frame.show();
}
}

class TreeEditFrame extends JFrame implements ActionListener {
public TreeEditFrame() {
setTitle("TreeEditTest");
setSize(300, 200);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});

// construct tree

TreeNode root = makeSampleTree();
model = new DefaultTreeModel(root);
tree = new JTree(model);
DefaultTreeCellRenderer renderer=new DefaultTreeCellRenderer();
renderer.setLeafIcon(new ImageIcon("1.gif"));
renderer.setClosedIcon(new ImageIcon("2.gif"));
renderer.setOpenIcon(new ImageIcon("3.gif&