Save me!! about JTree refresh!!

Question

Hello ereryone. I met a problem and I tried lots of method,such as reload(),validate(),revalidate(),but it seemed that they doesn't work.
My gui is about: here is a JSplitpane,on the left part ,there is a panel(borderlayou) in it. A button in the panel's west and a JScrollPane in the panel's center. A JTree component in the JScrollPane.
The wished fountion is when the program run, the tree would show the demanded disk file system(read config file to get the root file).when u click the button, a JFilechooser come out and u can choose another dir of the disk. when u click "ok", the tree should show the new file structure of the new dir.
here are 2 java file.
//myclass.java
//myclass.java
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import javax.swing.border.*;
import javax.swing.plaf.basic.*;
import javax.swing.ImageIcon;
import java.awt.dnd.*;
import java.awt.datatransfer.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
public class myclass extends JFrame implements WindowListener{
private JFrame f=null;
private JLabel labeladdress;
private JLabel labelstatus;
private JTree tree;
private JSplitPane splitPane;
private JEditorPane htmlPane;
private JPopupMenu Popup=null;
private DefaultTreeModel treeModel=null;
private String str="";
private boolean statusbarflag=true;
private boolean addressbarflag=true;
String currentpos;
ImageIcon icon=new ImageIcon("icons/paste.gif");
ReadAndWriteXML wp=new ReadAndWriteXML();
public WebPageSave(Vector vec) throws FileNotFoundException, SecurityException,Exception{
wp.address_Vector=new Vector();
wp.readXMLFile("sys/workposition.xml");
f=new JFrame("WebHunter");
Container contentPane=(JPanel)f.getContentPane();
contentPane.setLayout(new BorderLayout());
JPanel panel=new JPanel();
panel.setLayout(new BorderLayout());
paneln.setLayout(new BorderLayout());
contentPane.add(panel,BorderLayout.CENTER);
contentPane.add(paneln,BorderLayout.NORTH);
//添加JTree和JEditorPane
//JTree tree=new JTree();
initialtree(wp.address_Vector.get(0).toString());
final JScrollPane scrollPanel=new JScrollPane(tree);
final JPanel mainleft=new JPanel(new BorderLayout());
JButton jchange=new JButton("change position");
currentpos=wp.address_Vector.get(0).toString();
//the button anonymous class
jchange.addActionListener(new ActionListener(){   //change the dir
public void actionPerformed(ActionEvent event){
JFileChooser chooser=new JFileChooser(currentpos);
chooser.setDialogTitle("choose ur position");
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
int result=chooser.showDialog(f,"ok");
if(result==JFileChooser.APPROVE_OPTION){
int i=JOptionPane.showConfirmDialog(f,"make sure？","notice",JOptionPane.YES_NO_OPTION);
if(i==JOptionPane.YES_OPTION){
try{
//ReadAndWriteXML wp=new ReadAndWriteXML();
wp.address_Vector=new Vector();
wp.readXMLFile("sys/workposition.xml");
FileOperation u=new FileOperation();
u.xcopy(wp.address_Vector.get(0).toString(),chooser.getSelectedFile().toString());
u.delete(new File(wp.address_Vector.get(0).toString()));
}catch(Exception e){
e.printStackTrace();
//write the new positon to the workposition.xml文件
try{
wp.writeXMLFile("sys/workposition.xml",chooser.getSelectedFile().toString());
}catch (Exception e) {
e.printStackTrace();
?????? //refresh tree
try{
ReadAndWriteXML wp=new ReadAndWriteXML();
wp.address_Vector=new Vector();
wp.readXMLFile("sys/workposition.xml");
currentpos=wp.address_Vector.get(0).toString();
//currentpos=chooser.getSelectedFile().toString();
//initialtree(wp.address_Vector.get(0).toString());
initialtree(chooser.getSelectedFile().toString());
//JScrollPane scrollPanel=new JScrollPane(tree);
//mainleft.add(scrollPanel,BorderLayout.CENTER);
//tree.
//mainleft.validate();
JOptionPane.showConfirmDialog(f,"change positon successfully！","notice",JOptionPane.CLOSED_OPTION);
}catch (Exception e1) {
e1.printStackTrace();
mainleft.add(scrollPanel,BorderLayout.CENTER);
mainleft.add(jchange,BorderLayout.SOUTH);
JScrollPane scrollPane2=new JScrollPane(htmlPane);
splitPane=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true,mainleft,scrollPane2);
splitPane.setDividerSize(10);
splitPane.setDividerLocation(180);
panel.add(splitPane,BorderLayout.CENTER);
panel.add(labelstatus,BorderLayout.SOUTH);
f.pack();
f.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
f.setExtendedState(Frame.MAXIMIZED_BOTH);
f.setIconImage(icon.getImage());
//f.setBounds(0,0,1020,725);
f.show();
//f.addWindowListener(new WindowListenerHandle());
f.addWindowListener(this);
}//constructor over!!!
public void initialtree(String s) throws FileNotFoundException,SecurityException,Exception{
//ReadAndWriteXML treefile=new ReadAndWriteXML();
//treefile.address_Vector=new Vector();
//treefile.readXMLFile("sys/workposition.xml");
//tree=new FileTree(s);
//tree.revalidate();
//((DefaultTreeModel)tree.getModel()).nodeStructureChanged((DefaultTreeModel)s);
tree=new showDir().initTree(s);
tree.revalidate();
//DefaultTreeModel model=new DefaultTreeModel(tree.getModel());
//treeModel=(DefaultTreeModel) tree.getModel();
//tree.setModel(model);
//treeModel.reload();
tree.setEditable(true);
//FileTree.java
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.io.*;
import java.util.*;
public class FileTree extends JTree {
private static DefaultTreeModel model;
public FileTree(String path) throws FileNotFoundException, SecurityException {
super((TreeModel)null); // Create the JTree itself
// Use horizontal and vertical lines
putClientProperty("JTree.lineStyle", "Angled");
// Create the first node
FileTreeNode rootNode = new FileTreeNode(null, path);
model=new DefaultTreeModel(rootNode);
// Populate the root node with its subdirectories
boolean addedNodes = rootNode.populateDirectories(true);
//model.nodeStructureChanged(rootNode);
setModel(new DefaultTreeModel(rootNode));
//(new DefaultTreeModel(rootNode))this.getModel().reload();
//model.reload();
// Listen for Tree Selection Events
addTreeExpansionListener(new TreeExpansionHandler());
// Returns the full pathname for a path, or null if not a known path
public String getPathName(TreePath path) {
Object o = path.getLastPathComponent();
if (o instanceof FileTreeNode) {
return ((FileTreeNode)o).file.getAbsolutePath();
return null;
// Returns the File for a path, or null if not a known path
public File getFile(TreePath path) {
Object o = path.getLastPathComponent();
if (o instanceof FileTreeNode) {
return ((FileTreeNode)o).file;
return null;
// Inner class that represents a node in this file system tree
protected static class FileTreeNode extends DefaultMutableTreeNode {
public FileTreeNode(File parent, String name)
throws SecurityException, FileNotFoundException {
this.name = name;
// See if this node exists and whether it is a directory
file = new File(parent, name);
if (!file.exists()) {
throw new FileNotFoundException("File " + name + " does not exist");
isDir = file.isDirectory();
// Hold the File as the user object.
setUserObject(file);
// Override isLeaf to check whether this is a directory
public boolean isLeaf() {
return !isDir;
// Override getAllowsChildren to check whether this is a directory
public boolean getAllowsChildren() {
return !isDir;
// For display purposes, we return our own name
public String toString() {
return name;
// If we are a directory, scan our contents and populate
// with children. In addition, populate those children
// if the "descend" flag is true. We only descend once,
// to avoid recursing the whole subtree.
// Returns true if some nodes were added
boolean populateDirectories(boolean descend) {
boolean addedNodes = false;
// Do this only once
if (populated == false) {
if (interim == true) {
// We have had a quick look here before:
// remove the dummy node that we added last time
removeAllChildren();
interim = false;
String[] names = file.list(); // Get list of contents
// Process the directories
for (int i = 0; i < names.length; i++) {
String name = names;
File d = new File(file, name);
try {
FileTreeNode node = new FileTreeNode(file, name);
if (d.isDirectory()) {
//FileTreeNode node = new FileTreeNode(file, name);
this.add(node);
if (descend) {
node.populateDirectories(false);
addedNodes = true;
if (descend == false) {
// Only add one node if not descending
break;
else{   
//FileTreeNode node = new FileTreeNode(file,name);
this.add((MutableTreeNode)node);
//model.reload();
//model.nodeStructureChanged(node);
//((DefaultTreeModel)parent.getModel()).nodeStructureChanged(node);
} catch (Throwable t) {
// Ignore phantoms or access problems
// If we were scanning to get all subdirectories,
// or if we found no subdirectories, there is no
// reason to look at this directory again, so
// set populated to true. Otherwise, we set interim
// so that we look again in the future if we need to
if (descend == true || addedNodes == false) {
populated = true;
} else {
// Just set interim state
interim = true;
return addedNodes;
protected File file; // File object for this node
protected String name; // Name of this node
protected boolean populated;// true if we have been populated
protected boolean interim; // true if we are in interim state
protected boolean isDir; // true if this is a directory
// Inner class that handles Tree Expansion Events
protected class TreeExpansionHandler implements TreeExpansionListener {
public void treeExpanded(TreeExpansionEvent evt) {
TreePath path = evt.getPath(); // The expanded path
JTree tree = (JTree)evt.getSource(); // The tree
// Get the last component of the path and
// arrange to have it fully populated.
FileTreeNode node = (FileTreeNode)path.getLastPathComponent();
if (node.populateDirectories(true)) {
((DefaultTreeModel)tree.getModel()).nodeStructureChanged(node);
public void treeCollapsed(TreeExpansionEvent evt) {
// Nothing to do

Answer 1

There is a method for reloading a tree
Have a look at this:
http://java.sun.com/j2se/1.5.0/docs/api/javax/swing/tree/DefaultTreeModel.html#reload(javax.swing.tree.TreeNode)
Hope I understood your problem and it helps.