HELP PLEASE - Trees and JTree

[tecna_enchantix]

I have to use a tree structure to store bookmarks and history in the java tabbed web browser i must create :blink: This is what i have done so far

/**This class is the basis of the tree directory which will be used
 * to represent bookmarks and the browser history.
 * 
 * BrowserMutableTreeNode implements MutableTreeNode, therefore inheriting
 * its methods and those of TreeNode, since MutableTreeNode extends TreeNode.
 * 
 * 	@author CL WILLIAMS 15173534
 */

package cs214.trees;

import javax.swing.tree.MutableTreeNode;
import javax.swing.tree.TreeNode;
import java.util.*;

public class BrowserMutableTreeNode implements MutableTreeNode {
	
	/** This is a user defined object of any type.*/
	
	private Object userObject;
	
	/** This determines whether the node can have children or not.*/
	
	private boolean allowsChildren = true;
	
	/**This is the parent node.*/
	
	protected MutableTreeNode parent;
	
	/**The children are kept in an ArrayList of MutableTreeNodes.*/
	
	protected List <MutableTreeNode> children = new ArrayList<MutableTreeNode>();
	
	public BrowserMutableTreeNode(){
		BrowserMutableTreeNode rootNode = new BrowserMutableTreeNode();
	}
	
	/**This constructor creates a BrowserMutableTreeNode which receives
	 * an object as parameter.
	 * 
	 * @param o
	 * 		The user defined object to be stored in the node.
	 */
	
	public BrowserMutableTreeNode (Object o){
		//BrowserMutableTreeNode node = new BrowserMutableTreeNode(o);
		this.userObject = o;
	//makeNodes(rootNode);
	}
	
	/** This constructor creates a BrowserMutableTreeNode which receives an object 
	 * boolean as parameters.
	 * 
	 * @param o
	 * 		The user defined object to be stored in the node.
	 * 
	 * @param allowsChildren
	 * 		A boolean which returns true if the node is allowed to have
	 * 		children.
	 */		
	
	public BrowserMutableTreeNode (Object o, boolean allowsChildren){
	//BrowserMutableTreeNode node = new BrowserMutableTreeNode(o,allowsChildren);
	this.allowsChildren = allowsChildren;
	}

	/** This method inserts a new child into the ArrayList at the given index.
	 * 
	 * @param newChild
	 * 		The new node which will be inserted.
	 * 
	 * @param index
	 * 		The given index.
	 * 
	 */
	public void insert (MutableTreeNode newChild, int index) throws
		ArrayIndexOutOfBoundsException {
	   
		if (children == null){
		   children = new ArrayList<MutableTreeNode>();
	   }
	
		if(index < 0 || index > children.size()){
			throw new ArrayIndexOutOfBoundsException("You cannot access" +
					"that index.");
			
		}
		children.add(index,newChild);
		newChild.setParent(this);
	//newChild = new BrowserMutableTreeNode(o,true);   
	   
   }

	/** This method removes a node from the tree.
	 * 
	 */
	
	public void remove (MutableTreeNode node){
		
		if(children.remove(node)){
			node.setParent(null);
		}
	}
	
	/**
	 * 
	 * Removes the node at the given index.
	 * 
	 * @param index
	 * 		The given index
	 * 
	 * @throws ArrayIndexOutOfBoundsException
	 * 		This occurs when an illegal index is accessed.		
	 */
	
	public void remove (int index) throws ArrayIndexOutOfBoundsException{
		
		if (index < 0 || index > children.size()){
			throw new ArrayIndexOutOfBoundsException("You cannot access that index.");
		}
		MutableTreeNode child  = children.remove(index);
		child.setParent(null);
		
	}
	
	
	/** 
	 * 
	 * This method sets the user defined object as the object of this node.
	 * 
	 * @param o
	 * 		The user defined object.
	 * 
	 */
	
	public void setUserObject(Object o){
		this.userObject = o;
	}
	
	/**
	 * 
	 *  This method removes the current child from its parent.
	 * 
	 */
	public void removeFromParent(){
		
		if (parent == null){
			return;
		}
		parent.remove(this);
		
	}
	
	/** This method sets the parent node of a child.
	 * 
	 * @param newParent
	 * 		The node which will be the parent.
	 */
	
	public void setParent(MutableTreeNode newParent){
		
		this.parent = newParent;
		
	}
	
	/** This method gets the index of a given node.
	 * 
	 * @param node
	 * 		The given node
	 * 
	 * @return children.indexOf(node)
	 * 		The index of the given node
	 */
	
	public int getIndex(TreeNode node){
		 
		return children.indexOf(node);
	    	
	  }

	/** This method checks if the current node is allowed to have children.
	 * 
	 * @return allowsChildren
	 * 		Returns true if the node is allowed to have children.
	 */
	
    public boolean getAllowsChildren(){
    	
    	return allowsChildren;
    }
    
    /** This method returns the child at the given index.
     * 
     * @param childIndex
     * 		The index of the child
     * 
     * @return
     * 		The child at the given index
     * 
     * @throws ArrayIndexOutOfBoundsException
     * 		This occurs when an illegal index is accessed.
     * 		
     *
     */
    public TreeNode getChildAt(int childIndex) throws ArrayIndexOutOfBoundsException{
    	
    	if (childIndex < 0 || childIndex > children.size()) {
    		throw new ArrayIndexOutOfBoundsException("You cannot access that index.");
    	}
    	return children.get(childIndex);
    }
    
    /** This method has no parameters. It simply returns the parent of the current
     * node.
     * 
     * @return parent
     * 		The parent of the node which executed this method call.
     */
    
    public TreeNode getParent(){
    	
    	return parent;
    	
    }
    
    /** This method returns the number of children currently in the array.
     * 
     * @return children.size()
     * 		The size of the ArrayList, i.e. the number of children.
     */
    
    public int getChildCount(){
    	
    	if (children == null){
    		return 0;
    	}
    	
    	return children.size();
    }
    
    /** This method returns true if the child is a leaf node.
     * 
     * @return children.isEmpty();
     * 		Returns true if the child is not null and is a leaf node.
     * 
     */
    
    public boolean isLeaf(){
    	
    	return children.isEmpty();
    	
    }
    
    /**
     * 
     *  This Enumeration class returns an enumeration over the children of the
     * 	ArrayList.
     * 
     * @throws NoSuchElementException
     * 		This occurs when there are no more elements in the tree.
     * @return e
     * 		The enumeration over the list.
     * 
     */
    
    public Enumeration<MutableTreeNode> children() throws NoSuchElementException {
		/*Vector<MutableTreeNode> temp = new Vector<MutableTreeNode>();
		for(Enumeration<MutableTreeNode> e = temp.elements();e.hasMoreElements();)
		return temp;*/
    	Enumeration<MutableTreeNode> e = Collections.enumeration(children);
    	while(e.hasMoreElements()){
    		e.nextElement();
    	}
    	if(e.nextElement() == null){
    		throw new NoSuchElementException("There are no more elements" +
    				"to add to the enumeration.");
    	}
    	return e;
	}
    
    
    @Override
    
    /**This overrides the toString() method.
     * 
     * @return children().toString()
     * 		The string representation of the Enumeration over the ArrayList.
     *
     */
    
    public String toString(){
    	return children().toString();
    }
	    
}

ive attached the question in a pdf file. Im supposed to test if this works by creating a gui. For the bookmark GUI i have:

package cs214.tests;

import javax.swing.JTree;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JButton;
import javax.swing.UIManager;
import javax.swing.tree.MutableTreeNode;
import javax.swing.JEditorPane;
import javax.swing.UIManager;
import javax.swing.JTextField;
import javax.swing.event.TreeSelectionListener;
import javax.swing.event.TreeSelectionEvent;

import java.net.URL;

import java.awt.event.*;

import cs214.trees.BrowserMutableTreeNode;

public class Bookmark implements TreeSelectionListener{
	
	private JTree bookmarkTree;
	//private URL bookmarkURL;
	private BrowserMutableTreeNode newNode;
	private MutableTreeNode node;
	//private String bookmarkName;
	private JTextField currentSelection;
	
	private class BookmarkInfo {
		
		public String bookmarkTitle;
		public String description;
		public URL bookmarkURL;
		public String urlName;
		
		public BookmarkInfo(String title, String desc, String url){
			bookmarkTitle = title;
			description = desc;
			urlName = url;
			
			if (bookmarkURL == null) {
				System.err.println("You cannot have a null url.");
				
			}
			
			
		}
		
		public String toString(){
			return bookmarkTitle;
		}
		
	}
	
	public void makeNewNodes(BrowserMutableTreeNode top) {
		BrowserMutableTreeNode topNode = null;
		BrowserMutableTreeNode bookmark = null;
		
		topNode = new BrowserMutableTreeNode("Bookmarks");
		top.insert(topNode, 0);
		
		bookmark = new BrowserMutableTreeNode(new BookmarkInfo("Google","The Google Search Engine","www.google.com"));
		topNode.insert(bookmark,0);
		
		
		
	}
	
	public void valueChanged(TreeSelectionEvent event) {
	    MutableTreeNode node = (MutableTreeNode)bookmarkTree.getLastSelectedPathComponent();
		
		currentSelection.setText
	      ("Current Selection: " +
	       bookmarkTree.getLastSelectedPathComponent().toString());
	  }

	
	private static void createAndShowGUI() {
        /*if (useSystemLookAndFeel) {
            try {
                UIManager.setLookAndFeel(
                    UIManager.getSystemLookAndFeelClassName());
            } catch (Exception e) {
                System.err.println("Couldn't use system look and feel.");
            }
        }*/

        //Create and set up the window.
        JFrame frame = new JFrame("TreeDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel = new JPanel();
        //Add content to the window.
        bookmarkTree = new JTree(newNode);
        bookmarkTree.addTreeSelectionListener(this);
        frame.add(Bookmark);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
    	  
        //Schedule a job for the event dispatch thread:
        //creating and showing this application's GUI.
    	
    	new Bookmark();
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
		
		//BrowserMutableTreeNode topNode = new BrowserMutableTreeNode("Bookmarks");
		
		
		
		
	}

for the folder GUI i have:

/** This is the test file to create a folder tree.
 * 
 * @author CL WILLIAMS 15173534
 * 
 */

package cs214.tests;

import javax.swing.JRootPane;
import javax.swing.JTree;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JButton;
import javax.swing.tree.MutableTreeNode;

import java.awt.event.*;

import cs214.trees.BrowserMutableTreeNode;

public class Folder {
	
	private  static JTree folderTree;
	String folderName;
	private BrowserMutableTreeNode newNode;
	private MutableTreeNode node;
	
	public static void main(String[] args){
		
		BrowserMutableTreeNode topFolder = new BrowserMutableTreeNode("Root Folder",true);
		BrowserMutableTreeNode topFolderDescription = new BrowserMutableTreeNode("This is the root folder.");
		BrowserMutableTreeNode Folder1 = new BrowserMutableTreeNode("Folder 1",true);
		BrowserMutableTreeNode Folder1Description = new BrowserMutableTreeNode("This is the 1st folder in the root folder.");
		BrowserMutableTreeNode folder2 = new BrowserMutableTreeNode("Folder 2",true);
		BrowserMutableTreeNode folder2Description = new BrowserMutableTreeNode("This is the 2nd folder.");
		BrowserMutableTreeNode folder3 = new BrowserMutableTreeNode("Folder 3",true);
		BrowserMutableTreeNode folder3Description = new BrowserMutableTreeNode("1st Folder in Folder 2");
		
	//	folderTree = new JTree("Root Folder");
		JFrame frame = new JFrame("Bookmark JTree");
		JPanel panel = new JPanel();
		
		folderTree = new JTree(topFolder);
		topFolder.insert(topFolderDescription,0);
		topFolder.insert(Folder1,1);
		Folder1.insert(Folder1Description, 2);
		
		
		panel.add(folderTree);
		//panel.add(button);
		frame.add(panel);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setUndecorated(true);
		frame.getRootPane().setWindowDecorationStyle(JRootPane.PLAIN_DIALOG);
		frame.setSize(200,300);
		frame.setVisible(true);
		
		
		
	}
}

So all i need to know is if this tree structure actually works. Please can anyone help asap? thank you

i also have to extend the structure so that new bookmarks etc can be added and saved to disk :dizzy: