Path in JTree

How should I know where I click in jTree, actually I want to read the value of the selected node in JTree.
Thanks
Raheel

You can a implement a selection listener and get the node each time a selection is made.
Or from the API you can glean the method
Object getLastSelectedPathComponent()
Returns the last path component in the first node of the current selection.

Similar Messages

Path and JTree?

Hi everybody !!!
I would like to know how I can get the complete path of the JTree. I use the getLastSelectedPathComponent()) but it display only the folder. Do you know a method that can display the path of the folder?
tree.addMouseListener(new MouseAdapter()
     public void mousePressed(MouseEvent e)
          if (e.getModifiers()==e.BUTTON1_MASK) // Bouton gauche
                         planche.affichageGraphique(tree.getLastSelectedPathComponent());
          else if(e.getModifiers()==e.BUTTON3_MASK) // Bouton droit
                         f_temps.setVisible(true);
Thanks !!!

jTree.getSelectionPath()

Expand a path in JTree

Hi all. Please help, I am trying to programmatically expand JTree with JTree.expandPath(path), but it only works one level downwards from the last physically selected node. Is this a bug, or am I doing something wrong?

If you are using DefaultMutableTreeNode for your nodes, thenTreePath tp = new TreePath(theNode.getPath());gets you a path from the root to theNode. If you want that to be the selection, thentheTree.setSelectionPath(tp);and if you want it to be expanded and viewable thentheTree.expandPath(tp);If you aren't using DefaultMutableTreeNode, you will have to build the TreeNode[] that contains the nodes from the root down to theNode by some kind of loop; the rest of the code still works.

Expanding path on JTree

Hi.
I add a node to the default tree model and an event gets fired back to the listener (in this case the JTree itself). I then expand the path so as to show the new node to the user. A gap appears between the new node and the node in another branch below the new node. If I force a re-render (like with updateUI - erk!) the tree is drawn fine, otherwise its now. See the diagram below. If this a common problem and how do you fix it? Many thanks!
A +
|
+----B
|
+----C
Now I insert a node D, and I get:
A +
|
+----B
| |
| +----D
| <------- big gap :-(
|
+----C

import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
public class Test extends JFrame {
JTree jt = new JTree();
JButton jb = new JButton("Add");
public Test() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = getContentPane();
    content.add(new JScrollPane(jt),BorderLayout.CENTER);
    jt.setExpandsSelectedPaths(true);
    JButton jb = new JButton("Add");
    content.add(jb, BorderLayout.SOUTH);
    jb.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent ae) {
        TreePath tp = jt.getSelectionPath();
        if (tp!=null) {
          DefaultMutableTreeNode dmtn = (DefaultMutableTreeNode)tp.getLastPathComponent();
          DefaultMutableTreeNode newDmtn = new DefaultMutableTreeNode("Something");
          dmtn.add(newDmtn);
          ((javax.swing.tree.DefaultTreeModel)jt.getModel()).nodeStructureChanged(dmtn);
          jt.setSelectionPath(new TreePath(newDmtn.getPath()));
    setSize(200, 300);
    show();
public static void main(String args[]) { new Test(); }
}

Saving expanded paths

I've noticed that JTree keeps the expanded paths in some kind of cache. For example, if you expand a bunch of nodes under a certain parent, then collapse this parent and re-expand it again, all the previous expanded paths under this parent show up expanded again.
This means JTree (or maybe each node) keeps a memory of its expanded state. Is there a way to retrieve all the expanded paths at once? What I would like to do is have my application save these expanded paths (we have to deal with very large trees) to restore them later (for example when the user reloads the application.
Thanks for you thoughts :)

I know that...
My question is more, I want to make an algorythm that saves ALL paths that are expanded, so that I can later re-open the same paths when my application opens up again (after it was closed). What's the best way to do this?
My idea was :
-Put a tree expansion listener on my tree
-In this listener, when the path is expanded save it in some kind of list or Set. This will be a path of tree nodes, so I'll have to retrieve the path of my objects instead.
-Before my application closes, I save this path in some kind of user preferences (in file or in a datastore).
-When my application re-opens, at the time I build my tree, I need to replace my path of objects with their respective path of nodes.
-Then for each path of nodes, call the method
makeVisible(path) of JTree.

JTree select Node

Is there any method available to select a node by its path in JTree. I have to pass the argument as string type and see the node gets selected. Help !!!!

well, if you have the node and are using DefaultTreeModel, you can call: getPathToRoot(TreeNode)
Not sure how to find the node from the value except to just loop thru the entire tree... or maintain a separate table of value/node objects.

Directory equiv. to FileDialog class?

I want to select directories. The only other option I could think of is to model the drive paths as JTrees and the nodes as AbstractPaths...the problem with this is I can't work out how to initialise the JTree with the drives available on my computer without hard coding them which obviously isn't a very flexible solution! Or perhaps would this be a very long winded way of achieving what I want?

Thanks for your reply, I will look into that JFileChoser class. As I had a bit of spare time this afternoon I decided to try and program what I wanted anyway, found the listRoots() method and produced this;
public class DirectoryListing extends JPanel {
private JTree directoryTree;
//testing...
private DefaultMutableTreeNode selectedNode;
public DirectoryListing() {
    loadDrives();
    directoryTree.setRootVisible(false);
    directoryTree.setToggleClickCount(1);
    directoryTree.addTreeSelectionListener(new MyTreeListener());
    directoryTree.setCellRenderer(new MyCellRenderer());
    directoryTree.setShowsRootHandles(true);
    JScrollPane treeSP = new JScrollPane();
    treeSP.getViewport().add(directoryTree);
    setLayout(new BorderLayout());
    add(treeSP, BorderLayout.CENTER);
public void loadDrives(){
    DefaultMutableTreeNode root = new DefaultMutableTreeNode();
    File[] availableDrives = File.listRoots();
    for (int i = 0; i < availableDrives.length; i++) {
      DefaultMutableTreeNode aNode = new DefaultMutableTreeNode(availableDrives);
root.insert(aNode, root.getChildCount());
directoryLookAhead(aNode);
directoryTree = new JTree(root);
public class MyTreeListener implements TreeSelectionListener {
public void valueChanged(TreeSelectionEvent e) {
selectedNode = (DefaultMutableTreeNode) directoryTree.getLastSelectedPathComponent();
if (selectedNode != null) {
subDirectoryLookAhead(selectedNode);
public class MyCellRenderer extends JLabel implements TreeCellRenderer {
public MyCellRenderer() {
setOpaque(false);
public Component getTreeCellRendererComponent(JTree tree,
Object value,
boolean sel,
boolean expanded,
boolean leaf,
int row,
boolean hasFocus) {
File aFile = (File) ( ( (DefaultMutableTreeNode) value).getUserObject());
String text = aFile.getName();
if(text.length() == 0){
text = aFile.getPath();
setText(text);
if (sel || expanded) {
setIcon(UIManager.getIcon("Tree.openIcon"));
}else {
setIcon(UIManager.getIcon("Tree.closedIcon"));
if (sel) {
setForeground(Color.green);
}else {
setForeground(Color.black);
return this;
public void subDirectoryLookAhead(DefaultMutableTreeNode aNode) {
directoryLookAhead(aNode);
for (Enumeration n = aNode.children() ; n.hasMoreElements() ;) {
DefaultMutableTreeNode subNode = (DefaultMutableTreeNode) n.nextElement();
directoryLookAhead(subNode);
( (DefaultTreeModel) directoryTree.getModel()).reload();
public void directoryLookAhead(DefaultMutableTreeNode aNode){
File aFile = (File) aNode.getUserObject();
File[] directoryListing = aFile.listFiles();
if (directoryListing != null && directoryListing.length > 0 && aNode.getChildCount() == 0) {
for (int i = 0; i < directoryListing.length; i++) {
if (directoryListing[i].isDirectory()) {
aNode.insert(new DefaultMutableTreeNode(directoryListing[i]),aNode.getChildCount());
And, surprising it works, I must be getting better at this lark but alas, there's a few problems;
-You can only select leafs on the JTree - not nodes themselves - this is no good.
-If you invoke the JTree method 'setToggleClickCount' to anything other than 1, the tree keeps collapsing when reloading.
-Regardless of the setToggleClickCount if you double click on a node it also collapses the tree.
-I can't work how to get the hieracy lines to show.
-Finally, when you expand a node such as the windows directory (i.e. one with lots of sub directories) there's a little delay (i.e. its not as efficient as a standard implementation would be, when you run a file selector in any 'properly programed' program :) How does the 'proper' implementation differ from what I've tried to do here?
thanks for looking!

How to get the path when i select a directory or a file in a JTree

How to get the path when i select a directory or a file in a JTree

import java.lang.*;
import java.io.*;
import javax.swing.*;
import javax.swing.tree.*;
import java.awt.HeadlessException;
import javax.swing.event.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Iterator;
* @author Frederic FOURGEOT
* @version 1.0
public class JTreeFolder extends JPanel {
protected DefaultMutableTreeNode racine;
JTree tree;
protected JScrollPane scrollpane;
final static int MAX_LEVEL = 1; // niveau max de descente "direct" dans l'arborescence
* Sous-classe FSNode
* @author Frederic FOURGEOT
* @version 1.0
private class FSNode extends DefaultMutableTreeNode {
File file; // contient le fichier li� au noeud
* Constructeur non visible
private FSNode() {
super();
* Constructeur par initialisation
* @param userObject Object
FSNode(Object userObject) {
super(userObject);
* Constructeur par initialisation
* @param userObject Object
* @param newFile File
FSNode(Object userObject, File newFile) {
super(userObject);
file = newFile;
* Definit le fichier lie au noeud
* @param newFile File
public void setFile(File newFile) {
file = newFile;
* Renvoi le fichier lie au noeud
* @return File
public File getFile() {
return file;
public JTree getJTree(){
     return tree ;
* Constructeur
* @throws HeadlessException
public JTreeFolder() throws HeadlessException {
File[] drive;
tree = new JTree();
// cr�ation du noeud sup�rieur
racine = new DefaultMutableTreeNode("Poste de travail");
// cr�ation d'un noeud pour chaque lecteur
drive = File.listRoots();
for (int i = 0 ; i < drive.length ; i++) {
FSNode node = new FSNode(drive, drive[i]);
addFolder(drive[i], node); // on descend dans l'arborescence du lecteur jusqu'� MAX_LEVEL
racine.add(node);
// Gestion d'evenement sur JTree (on �coute les evenements TreeExpansion)
tree.addTreeExpansionListener(new TreeExpansionListener() {
public void treeExpanded(TreeExpansionEvent e) {
// lorsqu'un noeud est ouvert
// on descend dans l'arborescence du noeud jusqu'� MAX_LEVEL
TreePath path = e.getPath();
FSNode node = (FSNode)path.getLastPathComponent();
addFolder(node);
((DefaultTreeModel)tree.getModel()).reload(node); // on recharche uniquement le noeud
public void treeCollapsed(TreeExpansionEvent e) {
// lorsqu'un noeud est referm�
//RIEN
// alimentation du JTree
DefaultTreeModel model = new DefaultTreeModel(racine);
tree.setModel(model);
     setLayout(null);
// ajout du JTree au formulaire
tree.setBounds(0, 0, 240, 290);
scrollpane = new JScrollPane(tree);
     add(scrollpane);
     scrollpane.setBounds(0, 0, 240, 290);
* Recuperation des sous-elements d'un repertoire
* @param driveOrDir
* @param node
public void addFolder(File driveOrDir, DefaultMutableTreeNode node) {
setCursor(new Cursor(3)); // WAIT_CURSOR est DEPRECATED
addFolder(driveOrDir, node, 0);
setCursor(new Cursor(0)); // DEFAULT_CURSOR est DEPRECATED
* Recuperation des sous-elements d'un repertoire
* (avec niveau pour r�cursivit� et arr�t sur MAX_LEVEL)
* @param driveOrDir File
* @param node DefaultMutableTreeNode
* @param level int
private void addFolder(File driveOrDir, DefaultMutableTreeNode node, int level) {
File[] fileList;
fileList = driveOrDir.listFiles();
if (fileList != null) {
sortFiles(fileList); // on tri les elements
// on ne cherche pas plus loin que le niveau maximal d�finit
if (level > MAX_LEVEL - 1) {return;}
// pour chaque �l�ment
try {
for (int i = 0; i < fileList.length; i++) {
// en fonction du type d'�l�ment
if (fileList[i].isDirectory()) {
// si c'est un r�pertoire on cr�� un nouveau noeud
FSNode dir = new FSNode(fileList[i].getName(), fileList[i]);
node.add(dir);
// on recherche les �l�ments (r�cursivit�)
addFolder(fileList[i], dir, ++level);
if (fileList[i].isFile()) {
// si c'est un fichier on ajoute l'�l�ment au noeud
node.add(new FSNode(fileList[i].getName(), fileList[i]));
catch (NullPointerException e) {
// rien
* Recuperation des sous-elements d'un noeud
* @param node
public void addFolder(FSNode node) {
setCursor(new Cursor(3)); // WAIT_CURSOR est DEPRECATED
for (int i = 0 ; i < node.getChildCount() ; i++) {
addFolder(((FSNode)node.getChildAt(i)).getFile(), (FSNode)node.getChildAt(i));
setCursor(new Cursor(0)); // DEFAULT_CURSOR est DEPRECATED
* Tri une liste de fichier
* @param listFile
public void sortFiles(File[] listFile) {
triRapide(listFile, 0, listFile.length - 1);
* QuickSort : Partition
* @param listFile
* @param deb
* @param fin
* @return
private int partition(File[] listFile, int deb, int fin) {
int compt = deb;
File pivot = listFile[deb];
int i = deb - 1;
int j = fin + 1;
while (true) {
do {
j--;
} while (listFile[j].getName().compareToIgnoreCase(pivot.getName()) > 0);
do {
i++;
} while (listFile[i].getName().compareToIgnoreCase(pivot.getName()) < 0);
if (i < j) {
echanger(listFile, i, j);
} else {
return j;
* Tri rapide : quick sort
* @param listFile
* @param deb
* @param fin
private void triRapide(File[] listFile, int deb, int fin) {
if (deb < fin) {
int positionPivot = partition(listFile, deb, fin);
triRapide(listFile, deb, positionPivot);
triRapide(listFile, positionPivot + 1, fin);
* QuickSort : echanger
* @param listFile
* @param posa
* @param posb
private void echanger(File[] listFile, int posa, int posb) {
File tmpFile = listFile[posa];
listFile[posa] = listFile[posb];
listFile[posb] = tmpFile;

How to get the path of the selected Jtree node for deletion purpose

I had one Jtree which show the file structure of the system now i want to get the functionality like when i right click on the node , it should be delete and the file also deleted from my system, for that how can i get the path of that component
i had used
TreePath path = tree.getPathForLocation(loc.x, loc.y);
but it gives the array of objects as (from sop)=> [My Computer, C:\, C:\ANT_HOME, C:\ANT_HOME\lib, C:\ANT_HOME\lib\ant-1.7.0.pom.md5]
i want its last path element how can i get it ?

Call getLastSelectedPathComponent() on the tree.

Problem Expanding certain paths in a JTree

I am working with a JTree and trying to do the following:
My JTree is initially defined using the following code:
rootNode = new DefaultMutableTreeNode();
DefaultTreeModel treeModel = new DefaultTreeModel(rootNode);
tree = new JTree(treeModel);
//treeListener = new TreeSelectionListener();
tree.addTreeSelectionListener(treeListener);
DefaultTreeCellRenderer renderer = new DefaultTreeCellRenderer();
renderer.setLeafIcon(null);
tree.setCellRenderer(renderer);
tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
tree.setShowsRootHandles(true);
tree.setAutoscrolls(true);
tree.setExpandsSelectedPaths(true);
When a user selects a node, and presses some button, I get and save the current path (of the selected component) like this:
TreePath currentPath = tree.getSelectionPath();
Then I do some action on it, then repopulate the JTree
I have the following code at the bottom of the JTree populating method in an effort to expand the path in the tree which was last selected:
tree.expandPath(currentPath);
tree.setVisible(true);
tree.updateUI();
The problem is that when the tree repopulates, it stays completely collapsed, and I can't seem to figure out how automatically make it viewable in an expanded state (I don't want the user to have to go expand each expandable node by clicking beside it)
Does anyone know how to either expand the whole tree from the very beginning, or expand just the selected path?
Thanks in advance for your help,
Noha

To expand on path there is jtree.expandPath(treepath);
To expand the whole tree, I wrote a recursive method.

JTree path

I built a JTree thanks to several DefaultMutableTreeNode, wich were instantiate by:
new DefaultMutableTreeNode ( MyCategory );
MyCategory is an object from a class I made by my self (class CategoryNode)
The snag is, once I have this tree, I retrieve a given CategoryNode, and I must set the selection of my tree so that this CategoryNode is the one that will be selected.
I do not understand how to do it. I tried with the "setSelectionPath(TreePath path) " method, but I do not know how to built the TreePath. I do not understand how it works.
Someone can help me ? Someone as an example of this ?
Thank you very much !
Sylvain.

My english as bad as yours:-))
i'm russian
Just an example of finding suitable node.
import javax.swing.*;
import javax.swing.tree.*;
class Test extends JFrame
public Test()
super("Test");
DefaultMutableTreeNode root=new DefaultMutableTreeNode("ROOT");
DefaultMutableTreeNode n1=new DefaultMutableTreeNode("1");
DefaultMutableTreeNode n2=new DefaultMutableTreeNode("1_1");
n1.add(n2);
String category="founded";
n2=new DefaultMutableTreeNode("1_2");
n1.add(n2);
root.add(n1);
DefaultMutableTreeNode nnnn=new DefaultMutableTreeNode(category);
n2.add(nnnn);
n1=new DefaultMutableTreeNode("2");
root.add(n1);
JTree tree=new JTree(root);
DefaultMutableTreeNode node=findNode(root,category);
tree.setSelectionPath(new TreePath(node.getPath()));
JScrollPane scroll=new JScrollPane(tree);
getContentPane().add(scroll);
setSize(300,300);
setVisible(true);
public DefaultMutableTreeNode findNode(DefaultMutableTreeNode localRoot,Object category) {
DefaultMutableTreeNode resultNode=null;
if (localRoot.getUserObject().equals(category)) {
return localRoot;
int cnt=localRoot.getChildCount();
for (int i=0; i<cnt; i++) {
DefaultMutableTreeNode tempNode=findNode((DefaultMutableTreeNode)localRoot.getChildAt(i),category);
if (tempNode!=null) {
return tempNode;
return resultNode;
public static void main(String a[])
new Test();
best regards
Stas

JTree path selection

I have a JTree on the left scrollpane and on clicking the value of a node, I display the value in a text field on the right scrollpane. I change the value and set the value in the JTree . I am unable to make the edited tree path selected. The methods provided in the API do not seem to work.

Don't the JTree.makeVisible( ... ) or JTree.scrollPathToVisible( ... ) methods help?
kind regards,
Jos
Edited by: JosAH on Aug 23, 2009 6:19 PM: typo

JTree Path expansion help

Hi,
I have made my own jtree to load all the directories in the c drive. I am making a simple windows type browser. I allow users to select a driectory and create a new directory within it. The thing is, once this new directory is created it doesnt show up so i reinitialize the JTree to load all the directories again, and this time the new directory shows up in the directory it was created in. The problem is that before i reinitialize the tree again, i save a treepath for the directory the user is creating a new directory in., but after i reinitialize the tree i need to expand back to that path, i try using expandPath(savedTreePath) but its not working. Any ideas? Code is below.
private class NewFolderListener implements ActionListener {
          public void actionPerformed(ActionEvent evt) {
               DefaultMutableTreeNode selectedNode = (DefaultMutableTreeNode) tree
                         .getLastSelectedPathComponent();
               if (selectedNode == null) {
                    System.out.println("New folder not created");
                    return;
               File temp = (File) selectedNode.getUserObject();
               String newFolderPath = temp.getAbsolutePath() + "\\" + "New Folder";
               System.out.println(temp);
               temp = new File(newFolderPath);
               temp.mkdir();
                        TreePath tp = new TreePath(selectedNode.getPath);
               makeTree();
                         tree.expandPath(tp);
//Reinitialize tree method
private void makeTree() {
          try {
               //setLook();
               tree = new SimpleTree("C:\\");
               //location.setText("C:\\");
               splitPane.setLeftComponent(new JScrollPane(tree));
               tree.addTreeSelectionListener(new TreeSelectionListener() {
                   public void valueChanged(TreeSelectionEvent e) {
                       DefaultMutableTreeNode node = (DefaultMutableTreeNode)
                                          tree.getLastSelectedPathComponent();
                       if(node!=null){
                            MyFile mf = (MyFile)node.getUserObject();
                            location.setText(mf.getAbsolutePath());
                            fselected = mf;
                       makeRightPane();
               tree.setExpandsSelectedPaths(true);
               //cp.validate();
          } catch (Exception e) {
     }Anyone have any idea what i am doing wrong?

Well ive tried using the tree model, calling methods
such as reload() reload(node) , but none of the
reloaded the new directory which was created for the
node.The reload() method is only useful when you have modified existing nodes.
Use other methods defined in DefaultTreeModel to change tree structure.

Jtree; searching node by inserting path name

Hello,
I have a jtree which allows me to explore my harddisk.
The thing I want is finding a directory by inserting a path name ( with a JTextfield).
I am already able to reveice the inserted path.
But how do I let the JTree go to that inserted path name?
For more information, just ask.
Grtz

well, if you have the node and are using DefaultTreeModel, you can call: getPathToRoot(TreeNode)
Not sure how to find the node from the value except to just loop thru the entire tree... or maintain a separate table of value/node objects.

JTree path question

I have created a program that basically simulates single celled organisms in a random (non graphical) world, and I want to use a JTree to show the family history and allow the user to bring up an organism's stats by clicking on in the the Jtree, but I have a problem. Each organism has a unique ID number (starting at 0) and that's what I want to display on the tree. I have the code working to add the new organisms to the root, but I want them added as a child to the parent (each child has only one parent for these organisms), but I don't know how to do it. I tried using insertNodeInto but since everything after the root is dynamically generated I don't know how to identify the parent correctly (just using the ID doesn't seem to do anything). Do I need to create a method that somehow copies the entire treemodel into a collection and steps through it? I have the organisms in a collection already (an arraylist to be exact), so I could figure out the lineage by stepping through that, but then how do I build a 'selection path' object that will work to tell Java exactly where I want the child to go? Is the selection path just some kind of array, or is it even possible to build a selection path without a user clicking on a tree node? I hope you can figure out what I'm trying to say here and I appreciate any help you can give.

Start by creating a Map that has your organisms as the key and the nodes they are in as the value. Or just let the organism include a reference to the node that contains it. Either of those would allow you to identify the TreeNode that contains a particular organism.

Path in JTree

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