public SAX2DOM() throws ParserConfigurationException 
{
        
        synchronized (SAX2DOM.class) {
          _document = _factory.newDocumentBuilder().newDocument();
        }
        _root = _document;
}

 public SAX2DOM(Node root) throws ParserConfigurationException 
{
        this(root, null);
}

 public SAX2DOM(Node root,
    Node nextSibling) throws ParserConfigurationException 
{
        _root = root;
        if (root instanceof Document) {
          _document = (Document)root;
        }
        else if (root != null) {
          _document = root.getOwnerDocument();
        }
        else {
          synchronized (SAX2DOM.class) {
              _document = _factory.newDocumentBuilder().newDocument();
          }
          _root = _document;
        }
        _nextSibling = nextSibling;
}

 public  void characters(char[] ch,
    int start,
    int length) 
{
        // Ignore text nodes of length 0
        if (length == 0) {
            return;
        }
        final Node last = (Node)_nodeStk.peek();
        // No text nodes can be children of root (DOM006 exception)
        if (last != _document) {
            final String text = new String(ch, start, length);
            if( _lastSibling != null && _lastSibling.getNodeType() == Node.TEXT_NODE ){
                  ((Text)_lastSibling).appendData(text);
            }
            else if (last == _root && _nextSibling != null) {
                _lastSibling = last.insertBefore(_document.createTextNode(text), _nextSibling);
            }
            else {
                _lastSibling = last.appendChild(_document.createTextNode(text));
            }
        }
}

 public  void comment(char[] ch,
    int start,
    int length) 
{
        final Node last = (Node)_nodeStk.peek();
        Comment comment = _document.createComment(new String(ch,start,length));
        if (comment != null){
          if (last == _root && _nextSibling != null)
              last.insertBefore(comment, _nextSibling);
          else
              last.appendChild(comment);
          _lastSibling = comment;
        }
}

Lexical Handler method to create comment node in DOM tree.

 public  void endCDATA() 
{

}

 public  void endDTD() 
{

}

 public  void endDocument() 
{
        _nodeStk.pop();
}

 public  void endElement(String namespace,
    String localName,
    String qName) 
{
        _nodeStk.pop();
        _lastSibling = null;
}

 public  void endEntity(String name) 
{

}

 public  void endPrefixMapping(String prefix) 
{
        // do nothing
}

 public Node getDOM() 
{
        return _root;
}

 public  void ignorableWhitespace(char[] ch,
    int start,
    int length) 
{

}

This class is only used internally so this method should never be called.

 public  void processingInstruction(String target,
    String data) 
{
        final Node last = (Node)_nodeStk.peek();
        ProcessingInstruction pi = _document.createProcessingInstruction(
                target, data);
        if (pi != null){
          if (last == _root && _nextSibling != null)
              last.insertBefore(pi, _nextSibling);
          else
              last.appendChild(pi);
          _lastSibling = pi;
        }
}

adds processing instruction node to DOM.

 public  void setDocumentLocator(Locator locator) 
{
        this.locator = locator;
}

This class is only used internally so this method should never be called.

 public  void skippedEntity(String name) 
{

}

This class is only used internally so this method should never be called.

 public  void startCDATA() 
{

}

 public  void startDTD(String name,
    String publicId,
    String systemId) throws SAXException 
{

}

 public  void startDocument() 
{
        _nodeStk.push(_root);
}

 public  void startElement(String namespace,
    String localName,
    String qName,
    Attributes attrs) 
{
        if (needToSetDocumentInfo) {
            setDocumentInfo();
            needToSetDocumentInfo = false;
        }
        final Element tmp = (Element)_document.createElementNS(namespace, qName);
        // Add namespace declarations first
        if (_namespaceDecls != null) {
            final int nDecls = _namespaceDecls.size();
            for (int i = 0; i <  nDecls; i++) {
                final String prefix = (String) _namespaceDecls.elementAt(i++);
                if (prefix == null || prefix.equals(EMPTYSTRING)) {
                    tmp.setAttributeNS(XMLNS_URI, XMLNS_PREFIX,
                        (String) _namespaceDecls.elementAt(i));
                }
                else {
                    tmp.setAttributeNS(XMLNS_URI, XMLNS_STRING + prefix,
                        (String) _namespaceDecls.elementAt(i));
                }
            }
            _namespaceDecls.clear();
        }
        // Add attributes to element
/*      final int nattrs = attrs.getLength();
        for (int i = 0; i <  nattrs; i++) {
            if (attrs.getLocalName(i) == null) {
                tmp.setAttribute(attrs.getQName(i), attrs.getValue(i));
            }
            else {
                tmp.setAttributeNS(attrs.getURI(i), attrs.getQName(i),
                    attrs.getValue(i));
            }
        } */
        // Add attributes to element
        final int nattrs = attrs.getLength();
        for (int i = 0; i <  nattrs; i++) {
            // checking if Namespace processing is being done
            String attQName = attrs.getQName(i);
            String attURI = attrs.getURI(i);
            if (attrs.getLocalName(i).equals("")) {
                tmp.setAttribute(attQName, attrs.getValue(i));
                if (attrs.getType(i).equals("ID")) {
                    tmp.setIdAttribute(attQName, true);
                }
            } else {
                tmp.setAttributeNS(attURI, attQName, attrs.getValue(i));
                if (attrs.getType(i).equals("ID")) {
                    tmp.setIdAttributeNS(attURI, attrs.getLocalName(i), true);
                }
            }
        }
        // Append this new node onto current stack node
        Node last = (Node)_nodeStk.peek();
        // If the SAX2DOM is created with a non-null next sibling node,
        // insert the result nodes before the next sibling under the root.
        if (last == _root && _nextSibling != null)
            last.insertBefore(tmp, _nextSibling);
        else
            last.appendChild(tmp);
        // Push this node onto stack
        _nodeStk.push(tmp);
        _lastSibling = null;
}

 public  void startEntity(String name) 
{

}

 public  void startPrefixMapping(String prefix,
    String uri) 
{
        if (_namespaceDecls == null) {
            _namespaceDecls = new Vector(2);
        }
        _namespaceDecls.addElement(prefix);
        _namespaceDecls.addElement(uri);
}