Sax to DOM converter
/* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Revised from xmlbeans
import org.w3c.dom.Node;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.ProcessingInstruction;
import org.w3c.dom.Comment;
import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.ContentHandler;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.ext.LexicalHandler;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.DocumentBuilderFactory;
import java.util.Stack;
import java.util.Vector;
public class Sax2Dom
extends DefaultHandler
implements ContentHandler, LexicalHandler
{
public static final String EMPTYSTRING = "";
public static final String XML_PREFIX = "xml";
public static final String XMLNS_PREFIX = "xmlns";
public static final String XMLNS_STRING = "xmlns:";
public static final String XMLNS_URI = "http://www.w3.org/2000/xmlns/";
private Node _root = null;
private Document _document = null;
private Stack _nodeStk = new Stack();
private Vector _namespaceDecls = null;
public Sax2Dom() throws ParserConfigurationException
{
final DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
_document = factory.newDocumentBuilder().newDocument();
_root = _document;
}
public Sax2Dom(Node root) throws ParserConfigurationException
{
_root = root;
if (root instanceof Document)
{
_document = (Document) root;
}
else if (root != null)
{
_document = root.getOwnerDocument();
}
else
{
final DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
_document = factory.newDocumentBuilder().newDocument();
_root = _document;
}
}
public Node getDOM()
{
return _root;
}
public void characters(char[] ch, int start, int length)
{
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);
last.appendChild(_document.createTextNode(text));
}
}
public void startDocument()
{
_nodeStk.push(_root);
}
public void endDocument()
{
_nodeStk.pop();
}
public void startElement(String namespace, String localName, String qName,
Attributes attrs)
{
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));
}
}
// Append this new node onto current stack node
Node last = (Node) _nodeStk.peek();
last.appendChild(tmp);
// Push this node onto stack
_nodeStk.push(tmp);
}
public void endElement(String namespace, String localName, String qName)
{
_nodeStk.pop();
}
public void startPrefixMapping(String prefix, String uri)
{
if (_namespaceDecls == null)
{
_namespaceDecls = new Vector(2);
}
_namespaceDecls.addElement(prefix);
_namespaceDecls.addElement(uri);
}
public void endPrefixMapping(String prefix)
{
// do nothing
}
/**
* This class is only used internally so this method should never
* be called.
*/
public void ignorableWhitespace(char[] ch, int start, int length)
{
}
/**
* adds processing instruction node to DOM.
*/
public void processingInstruction(String target, String data)
{
final Node last = (Node) _nodeStk.peek();
ProcessingInstruction pi = _document.createProcessingInstruction(
target, data);
if (pi != null) last.appendChild(pi);
}
/**
* This class is only used internally so this method should never
* be called.
*/
public void setDocumentLocator(Locator locator)
{
}
/**
* This class is only used internally so this method should never
* be called.
*/
public void skippedEntity(String name)
{
}
/**
* Lexical Handler method to create comment node in DOM tree.
*/
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) last.appendChild(comment);
}
// Lexical Handler methods- not implemented
public void startCDATA()
{
}
public void endCDATA()
{
}
public void startEntity(java.lang.String name)
{
}
public void endEntity(String name)
{
}
public void startDTD(String name, String publicId, String systemId)
throws SAXException
{
}
public void endDTD()
{
}
}
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