How to save the changes made in Jtree to the source file

[rohit singh Patel]

Hi Friends,

I'm a newbie in Java and we are creating one application where we fetch the data from a file and creating a tree structure (JTree) and we are able to change the data in JTree but the changes which we made in JTree are not reflecting in our file. Please help me out with this how to push back the data to the same file with changes we made in JTree.

Thanks
Rohit Singh

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.StringTokenizer;

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

public class SelectableTree2 extends JFrame implements TreeSelectionListener {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	public static void main(String[] args) throws IOException {
		new SelectableTree2();
	}

	private JTree tree;
	private JTextField currentSelectionField;

	public SelectableTree2() throws IOException {
		super("JTree Selections");
		JPopupMenu popup; 
		
		WindowUtilities.setNativeLookAndFeel();
		addWindowListener(new ExitListener());
		Container content = getContentPane();

		File f = new File("F:\\JAVA\\Test.txt");
		if (!f.exists() || f.length() < 0) {
			System.out.println("The specified file does not exist");
		} else {
			FileReader fr = new FileReader(f);
			BufferedReader reader = new BufferedReader(fr);
			int i = 0;
			String st = "";
			DefaultMutableTreeNode tempNode = null;
			DefaultMutableTreeNode root = new DefaultMutableTreeNode("Dyna Menu");
			DefaultMutableTreeNode child = null;
			DefaultMutableTreeNode na;
			DefaultMutableTreeNode[] NodeArr = new DefaultMutableTreeNode[100];
			DefaultMutableTreeNode tempnode1 = null;
			String NA_ID="NA";
			na = new DefaultMutableTreeNode(NA_ID);
			root.add(na);
			tempNode = na;
			
			while ((st = reader.readLine()) != null) {
				StringTokenizer stoke = new StringTokenizer(st);
				String sno = stoke.nextToken();
				String grandChild_name = stoke.nextToken();
				String child_id = stoke.nextToken();
				child = new DefaultMutableTreeNode(grandChild_name);
				if (child_id.equals(tempNode.toString())) {
					tempNode.add(child);
					NodeArr[i] = child;
					i++;
				}
				else
				{
					for(int k=0; k<NodeArr.length; k++){
						if (NodeArr[k]!=null) 
						{
							String Nodename = NodeArr[k].toString();
							if (Nodename.equals(child_id)){
								tempnode1= new DefaultMutableTreeNode(grandChild_name);
								NodeArr[k].add(tempnode1);
							}
						}
					}
					NodeArr[i] = tempnode1;
					i++;
				}
			}
			tree = new JTree(root);
			tree.addTreeSelectionListener(this);
			content.add(new JScrollPane(tree), BorderLayout.CENTER);
			currentSelectionField = new JTextField("Current Selected Field: NONE");
			content.add(currentSelectionField, BorderLayout.SOUTH);
			setSize(500, 550);
			setVisible(true);					    
		}
		
		popup = new JPopupMenu(); 
		
		popup.setInvoker(tree); 
        PopupHandler handler = new PopupHandler(tree, popup); 
        popup.add(getMenuItem("add child",   handler)); 
        popup.add(getMenuItem("add sibling", handler)); 
        tree.setEditable(true);
	}
	
	 private JMenuItem getMenuItem(String s, ActionListener al) { 
	        JMenuItem menuItem = new JMenuItem(s); 
	        menuItem.setActionCommand(s.toUpperCase()); 
	        menuItem.addActionListener(al); 
	        
	        return menuItem; 
	        }

	public void valueChanged(TreeSelectionEvent event) {
		currentSelectionField.setText("Current Selected Field: "
				+ tree.getLastSelectedPathComponent().toString());
	}
    
}   

[Darryl Burke]

Rohit, please UseOneThreadPerQuestion. I'm locking this, discussion can continue in http://www.coderanch.com/t/566587/GUI/java/Changes-which-we-made-JTree