Help with displaying a JTree

Question

Hi,
I have developed a webspider that cycles through a website detecting all urls and checking for borken links. I currently have build a JTree that takes the current url that is being processed and creates a string and adds it to a JTree. The problem I have is that the urls are printed in the JTree as one long list, e.g.
|Test
|____url 1
|____url 1a
|____url 2
|____url 2a
I would like it to disply like this:
|Test
|____url 1
|-------|____url 1a
|____url 2
|-------|____url 2a
(I have had to place the dashes in so it displays properly)
So that the strucutre of the website can be seen. I have read the JTree tutroial and my code looks like this, sorry its large i'm not too sure which bits to cut out:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.net.*;
import java.io.*;
import java.util.*;
public class gui extends JFrame implements Runnable
      *declare variable, boolean
      *thread, a object and a center
      *pane
     protected URL urlInput;
     protected Thread bgThread;
     protected boolean run = false;
     protected WebSpider webSpider;
     public String brokenUrl;
     public String goodUrl;
     public String deadUrl;
     protected DefaultMutableTreeNode rootNode;
    protected DefaultTreeModel treeModel;
     public gui()
            *create the gui here
           setTitle("Testing Tool");
         setSize(600,600);
         //add Buttons to the tool bar
         start.setText("Start");
         start.setActionCommand("Start");
         toolBar.add(start);
         ButtonListener startListener = new ButtonListener();
             start.addActionListener(startListener);
          cancel.setText("Cancel");
         cancel.setActionCommand("Cancel");
         toolBar.add(cancel);
         ButtonListener cancelListener = new ButtonListener();
             cancel.addActionListener(cancelListener);
             clear.setText("Clear");
         clear.setActionCommand("Clear");
         toolBar.add(clear);
         ButtonListener clearListener = new ButtonListener();
             clear.addActionListener(clearListener);
             close.setText("Close");
         close.setActionCommand("Close");
         toolBar.add(close);
         ButtonListener closeListener = new ButtonListener();
             close.addActionListener(closeListener);
             //creat a simple form
             urlLabel.setText("Enter URL:");
             urlLabel.setBounds(100,36,288,24);
             formTab.add(urlLabel);
             url.setBounds(170,36,288,24);
             formTab.add(url);
             current.setText("Currently Processing: ");
             current.setBounds(100,80,288,24);
             formTab.add(current);
         //add the scrol pane and text area to the error tab
         errorTab.add(errorPane);
         errorPane.setBounds(0,0,580,490);
         errorPane.getViewport().add(errorText);
         //add the scroll pane to the tree tab
         treeTab.add(treePane);
         treePane.setBounds(0,0,580,490);
         //create the JTree
         rootNode = new DefaultMutableTreeNode("Test");
         treeModel = new DefaultTreeModel(rootNode);
         treeModel.addTreeModelListener(new MyTreeModelListener());
         tree = new JTree(treeModel);
         tree.setEditable(true);
         tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
        tree.setShowsRootHandles(true);
         treePane.getViewport().add(tree);
         //create the tabbed window             
        centerPane.setBorder(new javax.swing.border.EtchedBorder());
        formTab.setLayout(null);
        errorTab.setLayout(null);
        treeTab.setLayout(null);
        centerPane.addTab("Search Parameters", formTab);
        centerPane.addTab("Error Messages", errorTab);
        centerPane.addTab("Website Structure", treeTab);
          //add the tool bar and tabbed pane
          getContentPane().add(toolBar, java.awt.BorderLayout.NORTH);
        getContentPane().add(centerPane, java.awt.BorderLayout.CENTER);             
             *create the tool bar pane, a center pane, add the buttons,
             *labels, tabs, a text field for user input here
            javax.swing.JPanel toolBar = new javax.swing.JPanel();
            javax.swing.JButton start = new javax.swing.JButton();
          javax.swing.JButton cancel = new javax.swing.JButton();
          javax.swing.JButton clear = new javax.swing.JButton();
          javax.swing.JButton close = new javax.swing.JButton();      
            javax.swing.JTabbedPane centerPane = new javax.swing.JTabbedPane();
            javax.swing.JPanel formTab = new javax.swing.JPanel();
            javax.swing.JLabel urlLabel = new javax.swing.JLabel();
            javax.swing.JLabel current = new javax.swing.JLabel();
            javax.swing.JTextField url = new javax.swing.JTextField();
            javax.swing.JPanel errorTab = new javax.swing.JPanel();
            javax.swing.JTextArea errorText = new javax.swing.JTextArea();
            javax.swing.JScrollPane errorPane = new javax.swing.JScrollPane();
            javax.swing.JPanel treeTab = new javax.swing.JPanel();
            javax.swing.JScrollPane treePane = new javax.swing.JScrollPane();
            javax.swing.JTree tree = new javax.swing.JTree();
           *show the gui
          public static void main(String args[])
              (new gui()).setVisible(true);
          *listen for the button presses and set the
          *boolean flag depending on which button is pressed
         class ButtonListener implements ActionListener
              public void actionPerformed(ActionEvent event)
                   Object object = event.getSource();
                   if (object == start)
                        run = true;
                        startActionPerformed(event);
                   if (object == cancel)
                        run = false;
                        startActionPerformed(event);
                   if (object == clear)
                        errorText.setText("");
                        rootNode.removeAllChildren();
                       treeModel.reload();
                   if (object == close)
                        System.exit(0);
          *this method is called when the start or
          *cancel button is pressed.
         void startActionPerformed (ActionEvent event)
              if (run == true && bgThread == null)
                   bgThread = new Thread(this);
                   bgThread.start();
              if (run == false && bgThread != null)
                   webSpider.cancel();
          *this mehtod will start the background thred.
          *the background thread is required so that the
          *GUI is still displayed
         public void run()
              try
                       webSpider = new WebSpider(this);
                     webSpider.clear();
                     urlInput = new URL(url.getText());
                   webSpider.addURL(urlInput);
                   webSpider.run();
                   bgThread = null;
                  catch (MalformedURLException e)
                       addressError addErr = new addressError();
                     addErr.addMsg = "URL ERROR - PLEASE CHECK";
                     SwingUtilities.invokeLater(addErr);
             *this method is called by the web spider
             *once a url is found. Validation of navigation
             *happens here.
            public boolean urlFound(URL urlInput,URL url)
                  CurrentlyProcessing pro = new CurrentlyProcessing();
              pro.msg = url.toString();
              SwingUtilities.invokeLater(pro);
              if (!testLink(url))
                    navigationError navErr = new navigationError();
                    navErr.navMsg = "Broken Link "+url+" caused on "+urlInput+"\n";
                    brokenUrl = url.toString();
                    return false;
              if (!url.getHost().equalsIgnoreCase(urlInput.getHost()))
                    return false;
              else
                     return true;
            //this method is returned if there is no link on a web page
            public void urlNotFound(URL urlInput)
                      deadEnd dEnd = new deadEnd();
                       dEnd.dEMsg = "No links on "+urlInput+"\n";
                       deadUrl = urlInput.toString();                
            //this method is called internally to check that a link works              
            protected boolean testLink(URL url)
               try
                     URLConnection connection = url.openConnection();
                     connection.connect();
                     goodUrl = url.toString();
                     return true;
              catch (IOException e)
                     return false;
            //this method is called when an error is found            
            public void urlError(URL url)
          //this method is called when an email address is found             
            public void emailFound(String email)
          //this method will update any navigation errors found
          class addressError implements Runnable
               public String addMsg;
               public void run()
                    current.setText("Currently Processing: "+ addMsg);
                    errorText.append(addMsg);
          class navigationError implements Runnable
               public String navMsg;
               public void run()
                    errorText.append(navMsg);
          class deadEnd implements Runnable
               public String dEMsg;
               public void run()
                    errorText.append(dEMsg);
          //this method will update the currently processing field on the GUI
          public class CurrentlyProcessing implements Runnable
               public String msg;
              //public String msgInfo = msg;
                 public void run()
                     current.setText("Currently Processing: " + msg );
                     addObject(msg);
         //add a node to the tree
            public DefaultMutableTreeNode addObject (Object child)
             DefaultMutableTreeNode parentNode = null;
             return addObject(parentNode, child, true);
         public DefaultMutableTreeNode addObject(DefaultMutableTreeNode parent,Object child,boolean shouldBeVisible)
             DefaultMutableTreeNode childNode = new DefaultMutableTreeNode(child);
             if (parent == null)
                 parent = rootNode;
             treeModel.insertNodeInto(childNode, parent, parent.getChildCount());
             if (shouldBeVisible)
                 tree.scrollPathToVisible(new TreePath(childNode.getPath()));
                  return childNode;
         //listener for the tree model     
         public class MyTreeModelListener implements TreeModelListener
              public void treeNodesChanged (TreeModelEvent e)
                   DefaultMutableTreeNode node;
                   node = (DefaultMutableTreeNode)
                   (e.getTreePath().getLastPathComponent());
                   try
                        int index = e.getChildIndices()[0];
                        node = (DefaultMutableTreeNode)
                        (node.getChildAt(index));
                   catch (NullPointerException exc)
              public void treeNodesInserted(TreeModelEvent e)
              public void treeStructureChanged(TreeModelEvent e)
              public void treeNodesRemoved(TreeModelEvent e)
}It uses a class called webspider which i have not attached, if required please let me know. I beleive that in addObject I am adding all nodes to the root as children.
Any help would be much appreciated.
Many Thanks
MRv

Answer 1

I would recomend you create your own JTree class for this.
Here are a few things I set in my constructor within the JTree:
// turn on tooltips
ToolTipManager.sharedInstance().registerComponent(this);
// used by two setters so create reference
RollupTreeCellRenderer renderer = new RollupTreeCellRenderer();
// customizing the icons for the tree
// setting the folder icons
renderer.setOpenIcon(IconLoader.getIcon("Open.gif"));
renderer.setClosedIcon(IconLoader.getIcon("Folder.gif"));
// inventory icon
renderer.setLeafIcon(IconLoader.getIcon("Document.gif"));
// add renderer to highlight Inventory nodes with Red or Blue text
setCellRenderer(renderer);
Here is the renderer class example:
class RollupTreeCellRenderer
extends DefaultTreeCellRenderer
* Configures the renderer based on the passed in components.
* The value is set from messaging the tree with
* <code>convertValueToText</code>, which ultimately invokes
* <code>toString</code> on <code>value</code>.
* The foreground color is set based on the selection and the icon
* is set based on on leaf and expanded.
* @param tree JTree
* @param value Object
* @param sel boolean
* @param expanded boolean
* @param leaf boolean
* @param row int
* @param hasFocus boolean
* @return Component
public Component getTreeCellRendererComponent(JTree tree, Object value,
boolean sel,
boolean expanded,
boolean leaf, int row,
boolean hasFocus)
// call super for default behavior
super.getTreeCellRendererComponent(tree,
value,
sel,
expanded,
leaf,
row,
hasFocus);
// if the current node is selected do NOT over-ride
// the default colors
if (sel)
return this;
// cast to our wrapper Node class
RollupNode node = (RollupNode) value;
if (node.isInventory())
if (RollupMediator.getInstance().nodeInList(node))
setForeground(RollupTree.FOUND);
setToolTipText("Click to find positions count");
else
setForeground(RollupTree.NOT_FOUND);
setToolTipText("Inventory not in current business date");
else
setToolTipText("Double click to edit name");
return this;
} // Renderer
Let me know if you need more examples.
BTW
I the TreeCellRenderer example is not public so I can add it to the bottom of the file that contains my custom JTree.