Display JTree in browser using JSP

Question

i have a program that converts xml file in to tree structure(using Swing). When i run this using eclipse then it is working. Swing is an extension of applet , right. I want to embed this in an HTML page(JSP). so that i can display the tree structure. Its gives class not foung error.
It is not posiible to embed it. I think if it extends an Applet then it will display. But i don't know how to convert that. It gives error if i convert.
pls help
CODE:
package TreeGen;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.xml.sax.SAXException;
import java.io.IOException;
import org.w3c.dom.Document;
// Basic GUI components
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
// GUI components for right-hand side
import javax.swing.JSplitPane;
import javax.swing.JEditorPane;
// GUI support classes
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.event.WindowEvent;
import java.awt.event.WindowAdapter;
// For creating borders
import javax.swing.border.EmptyBorder;
import javax.swing.border.BevelBorder;
import javax.swing.border.CompoundBorder;
// For creating a TreeModel
import javax.swing.tree.*;
import javax.swing.event.*;
import java.util.*;
public class TreeGen extends JPanel
     static Document document;
     boolean compress = false;
     static final int windowHeight = 660;
     static final int leftWidth = 300;
     static final int rightWidth = 640;
     static final int windowWidth = leftWidth + rightWidth;
     public TreeGen()
     EmptyBorder eb = new EmptyBorder(5,5,5,5);
     BevelBorder bb = new BevelBorder(BevelBorder.LOWERED);
     CompoundBorder cb = new CompoundBorder(eb,bb);
     this.setBorder(new CompoundBorder(cb,eb));
     JTree tree = new JTree(new DomToTreeModelAdapter());
     JScrollPane treeView = new JScrollPane(tree);
     treeView.setPreferredSize(
          new Dimension( leftWidth, windowHeight ));
     final
     JEditorPane htmlPane = new JEditorPane("text/html","");
     htmlPane.setEditable(true);
     JScrollPane htmlView = new JScrollPane(htmlPane);
     htmlView.setPreferredSize(
          new Dimension( rightWidth, windowHeight ));
     tree.addTreeSelectionListener(
          new TreeSelectionListener()
          public void valueChanged(TreeSelectionEvent e)
               TreePath p = e.getNewLeadSelectionPath();
               if (p != null)
               AdapterNode adpNode =
                    (AdapterNode) p.getLastPathComponent();
               htmlPane.setText(adpNode.content());
     JSplitPane splitPane =
          new JSplitPane( JSplitPane.HORIZONTAL_SPLIT,
                              treeView,
                              htmlView );
     splitPane.setContinuousLayout( false );
     splitPane.setDividerLocation( leftWidth );
     splitPane.setDividerSize(1);
     splitPane.setPreferredSize(
               new Dimension( windowWidth + 10, windowHeight+10 ));
     this.setLayout(new BorderLayout());
     this.add("Center", splitPane );
     //return menuBar;
     } // constructor
     public static void main(String argv[])
          DocumentBuilderFactory factory =
               DocumentBuilderFactory.newInstance();
          try {
          DocumentBuilder builder = factory.newDocumentBuilder();
          document = builder.parse("C:/Program Files/Apache Software Foundation/Tomcat 5.0/webapps/parser1/sample.xml");
               makeFrame();
          } catch (SAXException sxe){
               System.out.println("ERROR");
          Exception x = sxe;
          if (sxe.getException() != null)
               x = sxe.getException();
          x.printStackTrace();
          } catch (ParserConfigurationException pce) {
               pce.printStackTrace();
          } catch (IOException ioe) {
          ioe.printStackTrace();
     } // main
     public static void makeFrame()
          JFrame frame = new JFrame("DOM Echo");
          frame.addWindowListener(
          new WindowAdapter() {
               public void windowClosing(WindowEvent e) {System.exit(0);}
          final TreeGen echoPanel =
          new TreeGen();
          frame.getContentPane().add("Center", echoPanel );
          frame.pack();
          Dimension screenSize =
          Toolkit.getDefaultToolkit().getScreenSize();
          int w = windowWidth + 10;
          int h = windowHeight + 10;
          frame.setSize(w, h);
          frame.setVisible(true);
     } // makeFrame
     static final String[] typeName = {
          "none",
          "Element",
          "Attr",
          "Text",
          "CDATA",
          "EntityRef",
          "Entity",
          "ProcInstr",
          "Comment",
          "Document",
          "DocType",
          "DocFragment",
          "Notation",
     static final int ELEMENT_TYPE = 1;
     static final int ATTR_TYPE = 2;
     static final int TEXT_TYPE = 3;
     static final int CDATA_TYPE = 4;
     static final int ENTITYREF_TYPE = 5;
     static final int ENTITY_TYPE = 6;
     static final int PROCINSTR_TYPE = 7;
     static final int COMMENT_TYPE = 8;
     static final int DOCUMENT_TYPE = 9;
     static final int DOCTYPE_TYPE = 10;
     static final int DOCFRAG_TYPE = 11;
     static final int NOTATION_TYPE = 12;
static String[] treeElementNames = {
          "slideshow",
          "slide",
          "title", // For slideshow #1
          "slide-title", // For slideshow #10
          "item",
     boolean treeElement(String elementName) {
     for (int i=0; i<treeElementNames.length; i++) {
          //System.out.println(treeElementNames);
          if ( elementName.equals(treeElementNames[i]) )
          return true;
     return false;
     public class AdapterNode
     org.w3c.dom.Node domNode;
     public AdapterNode(org.w3c.dom.Node node)
          domNode = node;
     public String toString()
          String s = typeName[domNode.getNodeType()];
          String nodeName = domNode.getNodeName();
          if (! nodeName.startsWith("#"))
          s += ": " + nodeName;
          if (compress)
          String t = content().trim();
          int x = t.indexOf("\n");
          if (x >= 0) t = t.substring(0, x);
          s += " " + t;
          return s;
          if (domNode.getNodeValue() != null)
          if (s.startsWith("ProcInstr"))
               s += ", ";
          else
               s += ": ";
          // Trim the value to get rid of NL's at the front
          String t = domNode.getNodeValue().trim();
          int x = t.indexOf("\n");
          if (x >= 0) t = t.substring(0, x);
          s += t;
          return s;
     public String content()
          String s = "";
          org.w3c.dom.NodeList nodeList = domNode.getChildNodes();
          for (int i=0; i<nodeList.getLength(); i++)
          org.w3c.dom.Node node = nodeList.item(i);
          int type = node.getNodeType();
          //System.out.println(type);
          AdapterNode adpNode = new AdapterNode(node); //inefficient, but works
          if (type == ELEMENT_TYPE)
               if ( treeElement(node.getNodeName()) ) continue;
               s += "<" + node.getNodeName() + ">";
               s += adpNode.content();
               s += "</" + node.getNodeName() + ">";
          else if (type == TEXT_TYPE)
               s += node.getNodeValue();
          else if (type == ENTITYREF_TYPE)
               s += adpNode.content();
          else if (type == CDATA_TYPE)
               StringBuffer sb = new StringBuffer( node.getNodeValue() );
               for (int j=0; j<sb.length(); j++)
               if (sb.charAt(j) == '<')
                    sb.setCharAt(j, '&');
                    sb.insert(j+1, "lt;");
                    j += 3;
               else if (sb.charAt(j) == '&')
                    sb.setCharAt(j, '&');
                    sb.insert(j+1, "amp;");
                    j += 4;
               s += "<pre>" + sb + "\n</pre>";
          return s;
     public int index(AdapterNode child)
          int count = childCount();
          for (int i=0; i<count; i++)
          AdapterNode n = this.child(i);
          if (child.domNode == n.domNode) return i;
          return -1; // Should never get here.
     public AdapterNode child(int searchIndex)
          org.w3c.dom.Node node =
               domNode.getChildNodes().item(searchIndex);
          if (compress)
          int elementNodeIndex = 0;
          for (int i=0; i<domNode.getChildNodes().getLength(); i++)
               node = domNode.getChildNodes().item(i);
               if (node.getNodeType() == ELEMENT_TYPE
               && treeElement( node.getNodeName() )
               && elementNodeIndex++ == searchIndex)
               break;
          return new AdapterNode(node);
     public int childCount()
          if (!compress)
          return domNode.getChildNodes().getLength();
          int count = 0;
          for (int i=0; i<domNode.getChildNodes().getLength(); i++)
          org.w3c.dom.Node node = domNode.getChildNodes().item(i);
          if (node.getNodeType() == ELEMENT_TYPE
          && treeElement( node.getNodeName() ))
               ++count;
          return count;
     public class DomToTreeModelAdapter
     implements javax.swing.tree.TreeModel
     public Object getRoot()
          return new AdapterNode(document);
     public boolean isLeaf(Object aNode)
          AdapterNode node = (AdapterNode) aNode;
          if (node.childCount() > 0) return false;
          return true;
     public int getChildCount(Object parent)
          AdapterNode node = (AdapterNode) parent;
          return node.childCount();
     public Object getChild(Object parent, int index)
          AdapterNode node = (AdapterNode) parent;
          return node.child(index);
     public int getIndexOfChild(Object parent, Object child)
          AdapterNode node = (AdapterNode) parent;
          return node.index((AdapterNode) child);
     public void valueForPathChanged(TreePath path, Object newValue)
     private Vector listenerList = new Vector();
     public void addTreeModelListener(TreeModelListener listener)
          if ( listener != null
          && ! listenerList.contains( listener ) )
          listenerList.addElement( listener );
     public void removeTreeModelListener(TreeModelListener listener)
          if ( listener != null )
          listenerList.removeElement( listener );
     public void fireTreeNodesChanged( TreeModelEvent e )
          Enumeration listeners = listenerList.elements();
          while ( listeners.hasMoreElements() )
          TreeModelListener listener =
               (TreeModelListener) listeners.nextElement();
          listener.treeNodesChanged( e );
     public void fireTreeNodesInserted( TreeModelEvent e )
          Enumeration listeners = listenerList.elements();
          while ( listeners.hasMoreElements() )
          TreeModelListener listener =
               (TreeModelListener) listeners.nextElement();
          listener.treeNodesInserted( e );
     public void fireTreeNodesRemoved( TreeModelEvent e )
          Enumeration listeners = listenerList.elements();
          while ( listeners.hasMoreElements() )
          TreeModelListener listener =
               (TreeModelListener) listeners.nextElement();
          listener.treeNodesRemoved( e );
     public void fireTreeStructureChanged( TreeModelEvent e )
          Enumeration listeners = listenerList.elements();
          while ( listeners.hasMoreElements() )
          TreeModelListener listener =
               (TreeModelListener) listeners.nextElement();
          listener.treeStructureChanged( e );

Answer 1

I actually had to do this a few months ago. There are ways to perform this kind display using various distributed object (i.e., using MS Word OLE objects to "interpret" the byte for you, etc.). But this soon got extremely difficult to manage (and I actually had to use Perl/CGI for the majority of it).
The solution I went with was to implement a "cache" directory on the web server. Basically, the JSP/Servlet can simply check the cache and if file not there, create it from the database. Then send a redirect back to the browser to this newly-created file. The browser will then appropriately open the document. I tested this with both Netscape and IE browsers and common MIME types such as text files, MS Office docs, zip files, PDFs, RTFs.
Not ideal, but unfortunately the best I came up with.