Save tree the lists of which is class' object

Question

Hi, my question :
how can i save tree the lists of which is class' object?
i save tree with the help of ObjectOutputStream class, but when i read tree object from file i have leaf without name(clean leaf)
how read and save tree in file for normal with it?
Code of my function for save tree:
import javax.swing.JTree;
import java.io.*;
import java.util.*;
public class SaveTree {
    public SaveTree(){
    public void saveTree(JTree tree){
        try{
        ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("tree.info"));
        out.writeObject(tree);
        out.close();
        catch(Exception e){
            e.printStackTrace();
    public JTree loadTree(){
        JTree tree = new JTree();
        try{
            ObjectInputStream in = new ObjectInputStream(new FileInputStream("tree.info"));
            tree = (JTree)in.readObject();
            in.close();
        catch(Exception e){
            e.printStackTrace();
        return tree;
}the code where i create new node as class' object
public void actionPerformed(ActionEvent e) {
        String command = e.getActionCommand();
        if (ADD_COMMAND.equals(command)) {
            //Add button clicked
            book = new DefaultMutableTreeNode(new BookInfo
            (name.getText(),
            "file:///"+ System.getProperty("user.dir") + "/" + ID.getText() + ".html", Integer.parseInt(ID.getText())));           
            treePanel.addObject(book);
            name.setText("");
            ID.setText("");
}my class BookInfo
public class BookInfo {
        public String bookName;
        public String bookURL;
        private int bookID;
        public BookInfo(String book, String filename, int ID) {
            bookID = ID;
            bookName = book;
            bookURL = filename;
            System.out.println(bookURL);
            if (bookURL == null) {
                System.err.println("Couldn't find file: "
                                   + filename);
        public String toString() {
            return bookName;
        public int getID(){
            return bookID;
        public void setID(int ID){
            bookID = ID;
    }thanks for attention ! :)

Answer 1

Jos, thanks for answer :)
Erm, get the TreeModel from the JTree, serialize it and later deserialize it and set it as the TreeModel for your JTree again?
kind regards,
JosHm, i save treeModel the same way, but when i (de)serialize treeModel from file i get clean tree
my function to save treeModel
class Save{
public Save(){}
public DefaultTreeModel loadModel(DefaultTreeModel model){
        try{
            ObjectInputStream in = new ObjectInputStream(new FileInputStream("tree.info"));
            model = (DefaultTreeModel)in.readObject();
            in.close();
        catch(Exception e){
            e.printStackTrace();
        return model;
        public DefaultTreeModel saveModel(DefaultTreeModel model){
        try{
            ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("tree.info"));
            out.writeObject(model);
            out.close();
        catch(Exception e){
            e.printStackTrace();
        //return model;
}and here i init tree with treeModel
Save save = new Save();
DefaultMutableTreeNode root = new DefaultMutableTreeNode(myObject);
DefaultTreeModel model = new DefaultTreeModel(root);
JTree tree = new JTree(save.saveModel(model));
JPanel panel  = new JPanel();
panel.add(new JScrollPane(tree));
this.add(panel);Edited by: Tmrs on May 18, 2008 6:00 AM