plugins/org.eclipse.wst.common.emf/wtpemf/org/eclipse/wst/common/internal/emf/utilities/DOMUtilities.java - webtools-common/webtools.common - Git at Google

 /*******************************************************************************
  * Copyright (c) 2003, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.wst.common.internal.emf.utilities;


 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
 import java.io.UnsupportedEncodingException;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;

 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;

 import org.eclipse.jem.util.logger.proxy.Logger;
 import org.w3c.dom.Document;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 import org.w3c.dom.Text;
 import org.xml.sax.EntityResolver;
 import org.xml.sax.ErrorHandler;
 import org.xml.sax.SAXException;
 import org.xml.sax.SAXParseException;

 /**
  * A class containing common dom manipulation and search functions.
  */
 public class DOMUtilities {
 	// Handy Constants
 	public static final String INDENT_STRING = "\t"; //$NON-NLS-1$
 	public static final String NEWLINE_STRING = System.getProperty("line.separator"); //$NON-NLS-1$
 	//Hack to be removed when the DOM apis change such that there is an easier
 	//way to fluff up and set the doctype
 	private static final String DUMMY_ENTITY_STRING = "dummy"; //$NON-NLS-1$
 	private static final String DUMMY_ENTITY_NODE_STRING = "<dummy/>"; //$NON-NLS-1$
 	private static DocumentBuilder defaultDocumentBuilder;
 	private static EntityResolver defaultEntityResolver;

 	/**
 	 * Returns an iterator that iterates over the sub nodes of a path.
 	 */
 	static public Iterator createPathIterator(String path) {
 		String tPath = path.startsWith("/") ? path.substring(1) : path; //$NON-NLS-1$
 		if (tPath.length() == 0)
 			tPath = null;
 		final String aPath = tPath;

 		return new Iterator() {
 			int prevIndex = 0;
 			int curIndex = 0;
 			String pathString = aPath;

 			public boolean hasNext() {
 				return pathString != null && prevIndex != -1;
 			}

 			public Object next() {
 				curIndex = pathString.indexOf('/', prevIndex);
 				String nodeString = null;
 				if (curIndex != -1)
 					nodeString = pathString.substring(prevIndex, curIndex++);
 				else
 					nodeString = pathString.substring(prevIndex);
 				prevIndex = curIndex;
 				return nodeString;
 			}

 			public void remove() {
 				throw new UnsupportedOperationException();
 			}
 		};
 	}

 	/**
 	 * Get the text for the passed in node.
 	 */
 	static public String getChildText(Node node) {
 		Text textNode = getChildTextNode(node);
 		if (textNode != null)
 			return textNode.getData();
 		return null;
 	}

 	/**
 	 * Get the text for the passed in node.
 	 */
 	static public Text getChildTextNode(Node node) {
 		Node textNode = node.getFirstChild();
 		while (textNode != null && DOMUtilities.isTextNode(textNode)) {
 			if (!isWhitespace(textNode))
 				return (Text) textNode;
 			textNode = textNode.getNextSibling();
 		}
 		return null;
 	}

 	/**
 	 * Return a string representing the current indentation of the node.
 	 */
 	static public String getIndentString(Node node) {
 		Revisit.toDo();
 		return ""; //$NON-NLS-1$
 	}

 	/**
 	 * Get the last non-text child of a node.
 	 *
 	 * @return org.w3c.dom.Node The last non-text child node of
 	 * @node.
 	 * @param node
 	 *            org.w3c.dom.Node The node
 	 */
 	public static Node getLastNodeChild(Node node) {
 		if (node == null)
 			return null;
 		Node child = node.getLastChild();
 		while (child != null && child.getNodeType() == Node.TEXT_NODE)
 			child = child.getPreviousSibling();
 		return child;
 	}

 	/**
 	 * Get the next non-text sibling after a node.
 	 *
 	 * @return org.w3c.dom.Node The first non-text sibling node after
 	 * @node. If there is no next non-text sibling, null is returned.
 	 * @param node
 	 *            org.w3c.dom.Node The node
 	 */
 	public static Node getNextNodeSibling(Node node) {
 		Node sibling = node.getNextSibling();
 		while (sibling != null && sibling.getNodeType() != Node.ELEMENT_NODE)
 			sibling = sibling.getNextSibling();
 		return sibling;
 	}

 	/**
 	 * Get the first child Node with the specified name
 	 */
 	static public Node getNodeChild(Node node, String nodeName) {
 		Node child = null;
 		NodeList children = node.getChildNodes();
 		for (int i = 0; i < children.getLength(); i++) {
 			Node n = children.item(i);
 			if (n.getNodeType() == Node.ELEMENT_NODE && n.getNodeName().equals(nodeName)) {
 				child = n;
 				break;
 			}
 		}
 		return child;
 	}

 	/**
 	 * Traverses the path passed in <pathName>. The path is a string in the form
 	 * 'node1/node2/node3'. This method starts at node.
 	 */
 	static public Node getNodeChildForPath(Node parent, String pathName) {

 		Node curNode = parent;
 		Iterator i = DOMUtilities.createPathIterator(pathName);
 		while (i.hasNext()) {
 			String child = (String) i.next();
 			curNode = DOMUtilities.getNodeChild(curNode, child);
 			if (curNode == null)
 				return null;
 		}
 		return curNode;
 	}

 	/**
 	 * Get the Node children with the specified names
 	 */
 	static public List getNodeChildren(Node node, String[] nodeNames) {
 		NodeList childNodes = node.getChildNodes();
 		ArrayList results = new ArrayList();

 		for (int i = 0; i < childNodes.getLength(); i++) {
 			Node n = childNodes.item(i);
 			if (n.getNodeType() == Node.ELEMENT_NODE) {
 				boolean found = false;
 				for (int j = 0; j < nodeNames.length; j++) {
 					if (nodeNames[j].equals(n.getNodeName())) {
 						found = true;
 						break;
 					}
 				}
 				if (found)
 					results.add(n);
 			}
 		}
 		return results;
 	}

 	/**
 	 * Get the Node children with the specified name
 	 */
 	static public List getNodeChildren(Node node, String nodeName) {
 		NodeList childNodes = node.getChildNodes();
 		ArrayList results = new ArrayList();

 		for (int i = 0; i < childNodes.getLength(); i++) {
 			Node n = childNodes.item(i);
 			if (n.getNodeType() == Node.ELEMENT_NODE && n.getNodeName().equals(nodeName))
 				results.add(n);
 		}
 		return results;
 	}

 	/**
 	 * Get the first non-text sibling before a node.
 	 *
 	 * @return org.w3c.dom.Node The first non-text sibling node before
 	 * @node. If there is no previous non-text sibling, null is returned.
 	 * @param node
 	 *            org.w3c.dom.Node The node
 	 */
 	public static Node getPreviousNodeSibling(Node node) {
 		if (node == null)
 			return null;
 		Node sibling = node.getPreviousSibling();
 		while (sibling != null && DOMUtilities.isTextNode(sibling))
 			sibling = sibling.getPreviousSibling();
 		return sibling;
 	}

 	/**
 	 * Get the first text node before a node.
 	 *
 	 * @return org.w3c.dom.Node The first text node before
 	 * @node. Null if no such node exist.
 	 * @param node
 	 *            org.w3c.dom.Node The node
 	 */
 	public static Text getPreviousText(Node node) {
 		Text sibling = getPreviousTextSibling(node);

 		if (sibling == null && node.getParentNode() != null)
 			sibling = getPreviousText(node.getParentNode());

 		return sibling;
 	}

 	/**
 	 * Get the first text sibling before a node.
 	 *
 	 * @return org.w3c.dom.Node The first text sibling node before
 	 * @node. If there is no previous text sibling, null is returned.
 	 * @param node
 	 *            org.w3c.dom.Node The node
 	 */
 	public static Text getPreviousTextSibling(Node node) {
 		Assert.isNotNull(node);

 		Node sibling = node.getPreviousSibling();
 		Node lastText = null;
 		while (sibling != null && sibling.getNodeType() == Node.TEXT_NODE) {
 			lastText = sibling;
 			sibling = sibling.getPreviousSibling();
 		}
 		return (Text) lastText;
 	}

 	/**
 	 * Get the first text sibling before a node.
 	 *
 	 * @return org.w3c.dom.Node The first text sibling node before
 	 * @node. If there is no previous text sibling, null is returned.
 	 * @param node
 	 *            org.w3c.dom.Node The node
 	 */
 	public static String getTrailingWhitespace(Text node) {
 		Assert.isNotNull(node);

 		String text = node.getData();
 		if (text.length() == 0)
 			return ""; //$NON-NLS-1$

 		int i = text.length() - 1;
 		for (; i >= 0; i--) {
 			if (!Character.isWhitespace(text.charAt(i))) {
 				break;
 			}
 		}

 		return text.substring(++i);
 	}

 	/**
 	 * Inserts <newNode>into <parent>after <refNode>. If <refNode>is null then the node is inserted
 	 * to the beginning of the parent's child nodes.
 	 *
 	 * @param parent
 	 *            org.w3c.dom.Node
 	 * @param newNode
 	 *            org.w3c.dom.Node
 	 * @param refNode
 	 *            org.w3c.dom.Node
 	 */
 	public static void insertAfterNode(Node parent, Node newNode, Node refNode) {
 		Node insertBeforeNode = null;
 		if (refNode != null) {
 			insertBeforeNode = refNode.getNextSibling();
 		}
 		if (refNode == null)
 			insertBeforeNode(parent, newNode, parent.getFirstChild());
 		else
 			insertBeforeNode(parent, newNode, insertBeforeNode);
 	}

 	/**
 	 * Insert a <newNode>into <parent>before <refNode>. This utility method is used to ensure that
 	 * the insertion does not result in two adjacent text nodes. The DOM model does not handle
 	 * adjacent text nodes. They must be joined together.
 	 *
 	 * @param newNode
 	 *            org.w3c.dom.Node
 	 * @param newNode
 	 *            org.w3c.dom.Node
 	 * @param refNode
 	 *            org.w3c.dom.Node
 	 */
 	static public void insertBeforeNode(Node parent, Node newNode, Node refNode) {
 		if (newNode.getNodeType() == Node.TEXT_NODE) {
 			Text textNewNode = (Text) newNode;

 			// If the insert before node is text, join it with the new node.
 			if (refNode != null && refNode.getNodeType() == Node.TEXT_NODE) {
 				Text textRefNode = (Text) refNode;
 				textRefNode.setData(textNewNode.getData() + textRefNode.getData());
 				return;
 			}
 			// If the node we are inserting after is text,
 			// join it with the new node.
 			Node insertAfterNode = (refNode == null) ? parent.getLastChild() : refNode.getPreviousSibling();
 			if (insertAfterNode != null && insertAfterNode.getNodeType() == Node.TEXT_NODE) {
 				Text textInsertAfterNode = (Text) insertAfterNode;
 				textInsertAfterNode.setData(textInsertAfterNode.getData() + textNewNode.getData());
 				return;
 			}
 		}
 		// There is no text node to join to, simple insert the node.
 		parent.insertBefore(newNode, refNode);
 	}

 	/**
 	 * Insert a <newNode>into <parent>before <refNode>. This method will also insert the node before
 	 * any whitespace nodes that appear in the tree before <refNode>. This method will also ensure
 	 * that the insertion does not result in two adjacent text nodes. The DOM model does not handle
 	 * adjacent text nodes. They must be joined together.
 	 *
 	 * @param newNode
 	 *            org.w3c.dom.Node
 	 * @param newNode
 	 *            org.w3c.dom.Node
 	 * @param refNode
 	 *            org.w3c.dom.Node
 	 */
 	static public void insertBeforeNodeAndWhitespace(Node parent, Node newNode, Node refNode) {
 		Node curNode = (refNode == null) ? parent.getLastChild() : refNode.getPreviousSibling();
 		Node lastNode = refNode;

 		while (curNode != null && (DOMUtilities.isWhitespace(curNode) || DOMUtilities.isComment(curNode))) {
 			lastNode = curNode;
 			curNode = curNode.getPreviousSibling();
 		}

 		insertBeforeNode(parent, newNode, lastNode);
 	}

 	/**
 	 * Return whether the node is a text node.
 	 *
 	 * @return boolean Answer true if the node is a text node, false otherwise.
 	 * @param node
 	 *            org.w3c.dom.Node The node to check
 	 */
 	static public boolean isTextNode(Node node) {
 		Assert.isNotNull(node);
 		return (node.getNodeType() == Node.TEXT_NODE) || (node.getNodeType() == Node.CDATA_SECTION_NODE);
 	}

 	/**
 	 * Return whether the node is entirely comment or not.
 	 *
 	 * @return boolean Answer true if the node is whitespace, false otherwise.
 	 * @param node
 	 *            org.w3c.dom.Node The node to check
 	 */
 	static public boolean isComment(Node node) {
 		Assert.isNotNull(node);

 		return node.getNodeType() == Node.COMMENT_NODE;
 	}

 	/**
 	 * Return whether the node is entirely whitepace or not.
 	 *
 	 * @return boolean Answer true if the node is whitespace, false otherwise.
 	 * @param node
 	 *            org.w3c.dom.Node The node to check
 	 */
 	static public boolean isWhitespace(Node node) {
 		Assert.isNotNull(node);

 		if (node.getNodeType() != Node.TEXT_NODE)
 			return false;

 		Text textNode = (Text) node;
 		String text = textNode.getData();
 		if (text == null)
 			return false;

 		for (int i = 0; i < text.length(); i++) {
 			if (!Character.isWhitespace(text.charAt(i))) {
 				return false;
 			}
 		}
 		return true;
 	}

 	/**
 	 * Remove all the children of <node>
 	 */
 	static public void removeAllChildren(Node node) {
 		NodeList list = node.getChildNodes();
 		for (int i = 0; i < list.getLength(); i++) {
 			node.removeChild(list.item(i));
 		}
 	}

 	// traverses the DOM starting at the specified node and returns a list
 	// of nodes matching the search string

 	static public ArrayList getAllNodes(Node node, String nodeName) {
 		ArrayList nodeList = new ArrayList();

 		String[] nodeNames = {nodeName};
 		findAllNodes(node, nodeNames, nodeList);

 		return nodeList;
 	}

 	// traverses the DOM starting at the specified node and returns a list
 	// of nodes matching the search strings

 	static public ArrayList getAllNodes(Node node, String[] nodeNamesArray) {
 		ArrayList nodeList = new ArrayList();
 		findAllNodes(node, nodeNamesArray, nodeList);

 		return nodeList;
 	}

 	// recursive helper for getAllNodes
 	static private void findAllNodes(Node node, String[] nodeNames, ArrayList results) {

 		NodeList nodes = node.getChildNodes();
 		if (nodes != null) {
 			for (int i = 0; i < nodes.getLength(); i++) {
 				for (int j = 0; j < nodeNames.length; j++) {
 					if (nodes.item(i).getNodeName().equals(nodeNames[j])) {
 						results.add(nodes.item(i));
 					}
 				}
 				findAllNodes(nodes.item(i), nodeNames, results);
 			}
 		}
 	}

 	/**
 	 * Returns the system defined JAXP document builder
 	 */
 	static public DocumentBuilder newDefaultDocumentBuilder(DOMLoadOptions options) throws ParserConfigurationException {
 		DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
 		dbf.setValidating(options.isValidate());
 		dbf.setNamespaceAware(options.isValidate());
 		/*
 		 * Causes errors in IBM JDK try { dbf.setAttribute(Renderer.JAXP_SCHEMA_LANGUAGE,
 		 * Renwderer.W3C_XML_SCHEMA); } catch (IllegalArgumentException x) { }
 		 */
 		try {
 			dbf.setAttribute("http://apache.org/xml/features/allow-java-encodings", new Boolean(options.isAllowJavaEncodings())); //$NON-NLS-1$
 		} catch (IllegalArgumentException ignore) {
 			Logger.getLogger().log("Warning: Parser does not support \"http://apache.org/xml/features/allow-java-encodings\"."); //$NON-NLS-1$
 		}
 		try {
 			dbf.setAttribute("http://apache.org/xml/features/validation/schema", new Boolean(options.isValidate())); //$NON-NLS-1$
 		} catch (IllegalArgumentException ignore) {
 			dbf.setValidating(false);
 			Logger.getLogger().log("Warning: Parser does not support \"http://apache.org/xml/features/validation/schema\". Validation will be disabled."); //$NON-NLS-1$
 		}
 		dbf.setExpandEntityReferences(options.isExpandEntityRefererences());
 		DocumentBuilder result = dbf.newDocumentBuilder();
 		result.setErrorHandler(new ErrorHandler() {
 			/*
 			 * (non-Javadoc)
 			 *
 			 * @see org.xml.sax.ErrorHandler#error(org.xml.sax.SAXParseException)
 			 */
 			public void error(SAXParseException arg0) throws SAXException {
 				throw arg0;
 			}

 			/*
 			 * (non-Javadoc)
 			 *
 			 * @see org.xml.sax.ErrorHandler#fatalError(org.xml.sax.SAXParseException)
 			 */
 			public void fatalError(SAXParseException arg0) throws SAXException {
 				throw arg0;
 			}

 			public void warning(SAXParseException arg0) throws SAXException {
 				Logger.getLogger().logWarning(arg0);
 			}

 		});
 		return result;
 	}

 	/**
 	 * Creates a stub document, where the DocumentType is defined by the parameters.
 	 */
 	static public Document createNewDocument(String doctype, String publicId, String systemId) throws ParserConfigurationException, SAXException, IOException {
 		DocumentBuilder builder = getDefaultDocumentBuilder();
 		InputStream in = createHeaderInputStream(doctype, publicId, systemId, true);
 		Document result = builder.parse(in);
 		removeDummyEntity(result);
 		removeExtraneousComments(result);
 		return result;
 	}

 	public static Document loadDocument(InputStream in, DOMLoadOptions options, EntityResolver resolver) throws ParserConfigurationException, SAXException, IOException {
 		DocumentBuilder builder = DOMUtilities.newDefaultDocumentBuilder(options);
 		builder.setEntityResolver(resolver);
 		Document result = builder.parse(in);
 		removeExtraneousComments(result);
 		return result;
 	}

 	/**
 	 * At the time of this writing, the DOM Level 2 APIs are not advanced enough for setting the
 	 * document type; so the only parser independent way of accomplishing this is by creating a
 	 * stream and parsing it.
 	 */
 	public static InputStream createHeaderInputStream(String doctype, String publicId, String systemId) {
 		return createHeaderInputStream(doctype, publicId, systemId, false);
 	}


 	private static InputStream createHeaderInputStream(String doctype, String publicId, String systemId, boolean includeDummy) {
         ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

 		// The prior code (which is still in the catch block), uses
 		// the system default encoding [System.getProperty("file.encoding")];
 		// on Z/OS this is Cp1047. The combination of "UTF-8" in the header
 		// and "Cp1047" in the writer create an unusable input stream.

 		PrintWriter writer;

 		try {
 			OutputStreamWriter outputWriter = new OutputStreamWriter(outputStream, "UTF-8"); //$NON-NLS-1$
 			// throws UnsupportedEncodingException
 			writer = new PrintWriter(outputWriter);
 		} catch (UnsupportedEncodingException e) {
 			// Should never get here (earlier code)
 			writer = new PrintWriter(outputStream);
 		}

 		writeHeader(writer, doctype, publicId, systemId);
 		if (includeDummy)
 			addDummyEntity(writer);
 		writer.flush();
 		writer.close();

 		byte[] bytes = outputStream.toByteArray();
 		return new ByteArrayInputStream(bytes);
 	}


 	private static void writeHeader(PrintWriter writer, String doctype, String publicId, String systemId) {
 		writer.write("<?xml version=\""); //$NON-NLS-1$
 		writer.write("1.0"); //$NON-NLS-1$
 		writer.write("\" encoding=\""); //$NON-NLS-1$
 		writer.write("UTF-8"); //$NON-NLS-1$
 		writer.write("\"?>"); //$NON-NLS-1$
 		writer.println();

 		if (doctype != null) {
 			writer.write("<!DOCTYPE "); //$NON-NLS-1$
 			writer.write(doctype);
 			writer.write(" PUBLIC \""); //$NON-NLS-1$
 			writer.write(publicId);
 			writer.write("\" \""); //$NON-NLS-1$
 			writer.write(systemId);
 			writer.write("\">"); //$NON-NLS-1$
 			writer.println();
 		}
 	}

 	private static void addDummyEntity(PrintWriter writer) {
 		Revisit.revisit();
 		writer.println(DUMMY_ENTITY_NODE_STRING);
 		//Major hack because we can not parse an empty document
 	}

 	private static void removeDummyEntity(Document doc) {
 		doc.removeChild(getNodeChild(doc, DUMMY_ENTITY_STRING));
 	}

 	private static void removeExtraneousComments(Document doc) {
 		//another major hack because of a bug in XML4J 4.0.7 that added all the
 		//comments from the dtd to the document. Can be removed after we move up
 		//Xerces levels
 		Node aNode = doc.getFirstChild();
 		while (aNode != null) {
 			Node nextNode = aNode.getNextSibling();
 			if (aNode.getNodeType() == Node.COMMENT_NODE)
 				doc.removeChild(aNode);
 			aNode = nextNode;
 		}
 	}

 	/**
 	 * For performance, cache a static instance of the JAXP registered document builder. Validation
 	 * is disabled for this instance. If you need validation, use
 	 * {@link #newDefaultDocumentBuilder(boolean, boolean, boolean)}
 	 *
 	 * @return DocumentBuilder
 	 * @throws ParserConfigurationException
 	 *             if JAXP is not configured correctly
 	 */
 	public static DocumentBuilder getDefaultDocumentBuilder() throws ParserConfigurationException {
 		if (defaultDocumentBuilder == null) {
 			DOMLoadOptions opts = new DOMLoadOptions();
 			opts.setAllowJavaEncodings(true);
 			opts.setExpandEntityRefererences(true);
 			opts.setValidate(false);
 			defaultDocumentBuilder = newDefaultDocumentBuilder(opts);
 			defaultDocumentBuilder.setEntityResolver(defaultEntityResolver);
 			defaultDocumentBuilder.setErrorHandler(new ErrorHandler() {
 				/*
 				 * (non-Javadoc)
 				 *
 				 * @see org.xml.sax.ErrorHandler#error(org.xml.sax.SAXParseException)
 				 */
 				public void error(SAXParseException exception) throws SAXException {

 				}

 				/*
 				 * (non-Javadoc)
 				 *
 				 * @see org.xml.sax.ErrorHandler#fatalError(org.xml.sax.SAXParseException)
 				 */
 				public void fatalError(SAXParseException exception) throws SAXException {

 				}

 				/*
 				 * (non-Javadoc)
 				 *
 				 * @see org.xml.sax.ErrorHandler#warning(org.xml.sax.SAXParseException)
 				 */
 				public void warning(SAXParseException exception) throws SAXException {

 				}

 			});
 		}

 		return defaultDocumentBuilder;
 	}

 	/**
 	 * @return
 	 */
 	public static EntityResolver getDefaultEntityResolver() {
 		return defaultEntityResolver;
 	}

 	/**
 	 * @param resolver
 	 */
 	public static void setDefaultEntityResolver(EntityResolver resolver) {
 		defaultEntityResolver = resolver;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2003, 2006 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.wst.common.internal.emf.utilities;


	import java.io.ByteArrayInputStream;
	import java.io.ByteArrayOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStreamWriter;
	import java.io.PrintWriter;
	import java.io.UnsupportedEncodingException;
	import java.util.ArrayList;
	import java.util.Iterator;
	import java.util.List;

	import javax.xml.parsers.DocumentBuilder;
	import javax.xml.parsers.DocumentBuilderFactory;
	import javax.xml.parsers.ParserConfigurationException;

	import org.eclipse.jem.util.logger.proxy.Logger;
	import org.w3c.dom.Document;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;
	import org.w3c.dom.Text;
	import org.xml.sax.EntityResolver;
	import org.xml.sax.ErrorHandler;
	import org.xml.sax.SAXException;
	import org.xml.sax.SAXParseException;

	/**
	* A class containing common dom manipulation and search functions.
	*/
	public class DOMUtilities {
	// Handy Constants
	public static final String INDENT_STRING = "\t"; //$NON-NLS-1$
	public static final String NEWLINE_STRING = System.getProperty("line.separator"); //$NON-NLS-1$
	//Hack to be removed when the DOM apis change such that there is an easier
	//way to fluff up and set the doctype
	private static final String DUMMY_ENTITY_STRING = "dummy"; //$NON-NLS-1$
	private static final String DUMMY_ENTITY_NODE_STRING = "<dummy/>"; //$NON-NLS-1$
	private static DocumentBuilder defaultDocumentBuilder;
	private static EntityResolver defaultEntityResolver;

	/**
	* Returns an iterator that iterates over the sub nodes of a path.
	*/
	static public Iterator createPathIterator(String path) {
	String tPath = path.startsWith("/") ? path.substring(1) : path; //$NON-NLS-1$
	if (tPath.length() == 0)
	tPath = null;
	final String aPath = tPath;

	return new Iterator() {
	int prevIndex = 0;
	int curIndex = 0;
	String pathString = aPath;

	public boolean hasNext() {
	return pathString != null && prevIndex != -1;
	}

	public Object next() {
	curIndex = pathString.indexOf('/', prevIndex);
	String nodeString = null;
	if (curIndex != -1)
	nodeString = pathString.substring(prevIndex, curIndex++);
	else
	nodeString = pathString.substring(prevIndex);
	prevIndex = curIndex;
	return nodeString;
	}

	public void remove() {
	throw new UnsupportedOperationException();
	}
	};
	}

	/**
	* Get the text for the passed in node.
	*/
	static public String getChildText(Node node) {
	Text textNode = getChildTextNode(node);
	if (textNode != null)
	return textNode.getData();
	return null;
	}

	/**
	* Get the text for the passed in node.
	*/
	static public Text getChildTextNode(Node node) {
	Node textNode = node.getFirstChild();
	while (textNode != null && DOMUtilities.isTextNode(textNode)) {
	if (!isWhitespace(textNode))
	return (Text) textNode;
	textNode = textNode.getNextSibling();
	}
	return null;
	}

	/**
	* Return a string representing the current indentation of the node.
	*/
	static public String getIndentString(Node node) {
	Revisit.toDo();
	return ""; //$NON-NLS-1$
	}

	/**
	* Get the last non-text child of a node.
	*
	* @return org.w3c.dom.Node The last non-text child node of
	* @node.
	* @param node
	* org.w3c.dom.Node The node
	*/
	public static Node getLastNodeChild(Node node) {
	if (node == null)
	return null;
	Node child = node.getLastChild();
	while (child != null && child.getNodeType() == Node.TEXT_NODE)
	child = child.getPreviousSibling();
	return child;
	}

	/**
	* Get the next non-text sibling after a node.
	*
	* @return org.w3c.dom.Node The first non-text sibling node after
	* @node. If there is no next non-text sibling, null is returned.
	* @param node
	* org.w3c.dom.Node The node
	*/
	public static Node getNextNodeSibling(Node node) {
	Node sibling = node.getNextSibling();
	while (sibling != null && sibling.getNodeType() != Node.ELEMENT_NODE)
	sibling = sibling.getNextSibling();
	return sibling;
	}

	/**
	* Get the first child Node with the specified name
	*/
	static public Node getNodeChild(Node node, String nodeName) {
	Node child = null;
	NodeList children = node.getChildNodes();
	for (int i = 0; i < children.getLength(); i++) {
	Node n = children.item(i);
	if (n.getNodeType() == Node.ELEMENT_NODE && n.getNodeName().equals(nodeName)) {
	child = n;
	break;
	}
	}
	return child;
	}

	/**
	* Traverses the path passed in <pathName>. The path is a string in the form
	* 'node1/node2/node3'. This method starts at node.
	*/
	static public Node getNodeChildForPath(Node parent, String pathName) {

	Node curNode = parent;
	Iterator i = DOMUtilities.createPathIterator(pathName);
	while (i.hasNext()) {
	String child = (String) i.next();
	curNode = DOMUtilities.getNodeChild(curNode, child);
	if (curNode == null)
	return null;
	}
	return curNode;
	}

	/**
	* Get the Node children with the specified names
	*/
	static public List getNodeChildren(Node node, String[] nodeNames) {
	NodeList childNodes = node.getChildNodes();
	ArrayList results = new ArrayList();

	for (int i = 0; i < childNodes.getLength(); i++) {
	Node n = childNodes.item(i);
	if (n.getNodeType() == Node.ELEMENT_NODE) {
	boolean found = false;
	for (int j = 0; j < nodeNames.length; j++) {
	if (nodeNames[j].equals(n.getNodeName())) {
	found = true;
	break;
	}
	}
	if (found)
	results.add(n);
	}
	}
	return results;
	}

	/**
	* Get the Node children with the specified name
	*/
	static public List getNodeChildren(Node node, String nodeName) {
	NodeList childNodes = node.getChildNodes();
	ArrayList results = new ArrayList();

	for (int i = 0; i < childNodes.getLength(); i++) {
	Node n = childNodes.item(i);
	if (n.getNodeType() == Node.ELEMENT_NODE && n.getNodeName().equals(nodeName))
	results.add(n);
	}
	return results;
	}

	/**
	* Get the first non-text sibling before a node.
	*
	* @return org.w3c.dom.Node The first non-text sibling node before
	* @node. If there is no previous non-text sibling, null is returned.
	* @param node
	* org.w3c.dom.Node The node
	*/
	public static Node getPreviousNodeSibling(Node node) {
	if (node == null)
	return null;
	Node sibling = node.getPreviousSibling();
	while (sibling != null && DOMUtilities.isTextNode(sibling))
	sibling = sibling.getPreviousSibling();
	return sibling;
	}

	/**
	* Get the first text node before a node.
	*
	* @return org.w3c.dom.Node The first text node before
	* @node. Null if no such node exist.
	* @param node
	* org.w3c.dom.Node The node
	*/
	public static Text getPreviousText(Node node) {
	Text sibling = getPreviousTextSibling(node);

	if (sibling == null && node.getParentNode() != null)
	sibling = getPreviousText(node.getParentNode());

	return sibling;
	}

	/**
	* Get the first text sibling before a node.
	*
	* @return org.w3c.dom.Node The first text sibling node before
	* @node. If there is no previous text sibling, null is returned.
	* @param node
	* org.w3c.dom.Node The node
	*/
	public static Text getPreviousTextSibling(Node node) {
	Assert.isNotNull(node);

	Node sibling = node.getPreviousSibling();
	Node lastText = null;
	while (sibling != null && sibling.getNodeType() == Node.TEXT_NODE) {
	lastText = sibling;
	sibling = sibling.getPreviousSibling();
	}
	return (Text) lastText;
	}

	/**
	* Get the first text sibling before a node.
	*
	* @return org.w3c.dom.Node The first text sibling node before
	* @node. If there is no previous text sibling, null is returned.
	* @param node
	* org.w3c.dom.Node The node
	*/
	public static String getTrailingWhitespace(Text node) {
	Assert.isNotNull(node);

	String text = node.getData();
	if (text.length() == 0)
	return ""; //$NON-NLS-1$

	int i = text.length() - 1;
	for (; i >= 0; i--) {
	if (!Character.isWhitespace(text.charAt(i))) {
	break;
	}
	}

	return text.substring(++i);
	}

	/**
	* Inserts <newNode>into <parent>after <refNode>. If <refNode>is null then the node is inserted
	* to the beginning of the parent's child nodes.
	*
	* @param parent
	* org.w3c.dom.Node
	* @param newNode
	* org.w3c.dom.Node
	* @param refNode
	* org.w3c.dom.Node
	*/
	public static void insertAfterNode(Node parent, Node newNode, Node refNode) {
	Node insertBeforeNode = null;
	if (refNode != null) {
	insertBeforeNode = refNode.getNextSibling();
	}
	if (refNode == null)
	insertBeforeNode(parent, newNode, parent.getFirstChild());
	else
	insertBeforeNode(parent, newNode, insertBeforeNode);
	}

	/**
	* Insert a <newNode>into <parent>before <refNode>. This utility method is used to ensure that
	* the insertion does not result in two adjacent text nodes. The DOM model does not handle
	* adjacent text nodes. They must be joined together.
	*
	* @param newNode
	* org.w3c.dom.Node
	* @param newNode
	* org.w3c.dom.Node
	* @param refNode
	* org.w3c.dom.Node
	*/
	static public void insertBeforeNode(Node parent, Node newNode, Node refNode) {
	if (newNode.getNodeType() == Node.TEXT_NODE) {
	Text textNewNode = (Text) newNode;

	// If the insert before node is text, join it with the new node.
	if (refNode != null && refNode.getNodeType() == Node.TEXT_NODE) {
	Text textRefNode = (Text) refNode;
	textRefNode.setData(textNewNode.getData() + textRefNode.getData());
	return;
	}
	// If the node we are inserting after is text,
	// join it with the new node.
	Node insertAfterNode = (refNode == null) ? parent.getLastChild() : refNode.getPreviousSibling();
	if (insertAfterNode != null && insertAfterNode.getNodeType() == Node.TEXT_NODE) {
	Text textInsertAfterNode = (Text) insertAfterNode;
	textInsertAfterNode.setData(textInsertAfterNode.getData() + textNewNode.getData());
	return;
	}
	}
	// There is no text node to join to, simple insert the node.
	parent.insertBefore(newNode, refNode);
	}

	/**
	* Insert a <newNode>into <parent>before <refNode>. This method will also insert the node before
	* any whitespace nodes that appear in the tree before <refNode>. This method will also ensure
	* that the insertion does not result in two adjacent text nodes. The DOM model does not handle
	* adjacent text nodes. They must be joined together.
	*
	* @param newNode
	* org.w3c.dom.Node
	* @param newNode
	* org.w3c.dom.Node
	* @param refNode
	* org.w3c.dom.Node
	*/
	static public void insertBeforeNodeAndWhitespace(Node parent, Node newNode, Node refNode) {
	Node curNode = (refNode == null) ? parent.getLastChild() : refNode.getPreviousSibling();
	Node lastNode = refNode;

	while (curNode != null && (DOMUtilities.isWhitespace(curNode) \|\| DOMUtilities.isComment(curNode))) {
	lastNode = curNode;
	curNode = curNode.getPreviousSibling();
	}

	insertBeforeNode(parent, newNode, lastNode);
	}

	/**
	* Return whether the node is a text node.
	*
	* @return boolean Answer true if the node is a text node, false otherwise.
	* @param node
	* org.w3c.dom.Node The node to check
	*/
	static public boolean isTextNode(Node node) {
	Assert.isNotNull(node);
	return (node.getNodeType() == Node.TEXT_NODE) \|\| (node.getNodeType() == Node.CDATA_SECTION_NODE);
	}

	/**
	* Return whether the node is entirely comment or not.
	*
	* @return boolean Answer true if the node is whitespace, false otherwise.
	* @param node
	* org.w3c.dom.Node The node to check
	*/
	static public boolean isComment(Node node) {
	Assert.isNotNull(node);

	return node.getNodeType() == Node.COMMENT_NODE;
	}

	/**
	* Return whether the node is entirely whitepace or not.
	*
	* @return boolean Answer true if the node is whitespace, false otherwise.
	* @param node
	* org.w3c.dom.Node The node to check
	*/
	static public boolean isWhitespace(Node node) {
	Assert.isNotNull(node);

	if (node.getNodeType() != Node.TEXT_NODE)
	return false;

	Text textNode = (Text) node;
	String text = textNode.getData();
	if (text == null)
	return false;

	for (int i = 0; i < text.length(); i++) {
	if (!Character.isWhitespace(text.charAt(i))) {
	return false;
	}
	}
	return true;
	}

	/**
	* Remove all the children of <node>
	*/
	static public void removeAllChildren(Node node) {
	NodeList list = node.getChildNodes();
	for (int i = 0; i < list.getLength(); i++) {
	node.removeChild(list.item(i));
	}
	}

	// traverses the DOM starting at the specified node and returns a list
	// of nodes matching the search string

	static public ArrayList getAllNodes(Node node, String nodeName) {
	ArrayList nodeList = new ArrayList();

	String[] nodeNames = {nodeName};
	findAllNodes(node, nodeNames, nodeList);

	return nodeList;
	}

	// traverses the DOM starting at the specified node and returns a list
	// of nodes matching the search strings

	static public ArrayList getAllNodes(Node node, String[] nodeNamesArray) {
	ArrayList nodeList = new ArrayList();
	findAllNodes(node, nodeNamesArray, nodeList);

	return nodeList;
	}

	// recursive helper for getAllNodes
	static private void findAllNodes(Node node, String[] nodeNames, ArrayList results) {

	NodeList nodes = node.getChildNodes();
	if (nodes != null) {
	for (int i = 0; i < nodes.getLength(); i++) {
	for (int j = 0; j < nodeNames.length; j++) {
	if (nodes.item(i).getNodeName().equals(nodeNames[j])) {
	results.add(nodes.item(i));
	}
	}
	findAllNodes(nodes.item(i), nodeNames, results);
	}
	}
	}

	/**
	* Returns the system defined JAXP document builder
	*/
	static public DocumentBuilder newDefaultDocumentBuilder(DOMLoadOptions options) throws ParserConfigurationException {
	DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
	dbf.setValidating(options.isValidate());
	dbf.setNamespaceAware(options.isValidate());
	/*
	* Causes errors in IBM JDK try { dbf.setAttribute(Renderer.JAXP_SCHEMA_LANGUAGE,
	* Renwderer.W3C_XML_SCHEMA); } catch (IllegalArgumentException x) { }
	*/
	try {
	dbf.setAttribute("http://apache.org/xml/features/allow-java-encodings", new Boolean(options.isAllowJavaEncodings())); //$NON-NLS-1$
	} catch (IllegalArgumentException ignore) {
	Logger.getLogger().log("Warning: Parser does not support \"http://apache.org/xml/features/allow-java-encodings\"."); //$NON-NLS-1$
	}
	try {
	dbf.setAttribute("http://apache.org/xml/features/validation/schema", new Boolean(options.isValidate())); //$NON-NLS-1$
	} catch (IllegalArgumentException ignore) {
	dbf.setValidating(false);
	Logger.getLogger().log("Warning: Parser does not support \"http://apache.org/xml/features/validation/schema\". Validation will be disabled."); //$NON-NLS-1$
	}
	dbf.setExpandEntityReferences(options.isExpandEntityRefererences());
	DocumentBuilder result = dbf.newDocumentBuilder();
	result.setErrorHandler(new ErrorHandler() {
	/*
	* (non-Javadoc)
	*
	* @see org.xml.sax.ErrorHandler#error(org.xml.sax.SAXParseException)
	*/
	public void error(SAXParseException arg0) throws SAXException {
	throw arg0;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.xml.sax.ErrorHandler#fatalError(org.xml.sax.SAXParseException)
	*/
	public void fatalError(SAXParseException arg0) throws SAXException {
	throw arg0;
	}

	public void warning(SAXParseException arg0) throws SAXException {
	Logger.getLogger().logWarning(arg0);
	}

	});
	return result;
	}

	/**
	* Creates a stub document, where the DocumentType is defined by the parameters.
	*/
	static public Document createNewDocument(String doctype, String publicId, String systemId) throws ParserConfigurationException, SAXException, IOException {
	DocumentBuilder builder = getDefaultDocumentBuilder();
	InputStream in = createHeaderInputStream(doctype, publicId, systemId, true);
	Document result = builder.parse(in);
	removeDummyEntity(result);
	removeExtraneousComments(result);
	return result;
	}

	public static Document loadDocument(InputStream in, DOMLoadOptions options, EntityResolver resolver) throws ParserConfigurationException, SAXException, IOException {
	DocumentBuilder builder = DOMUtilities.newDefaultDocumentBuilder(options);
	builder.setEntityResolver(resolver);
	Document result = builder.parse(in);
	removeExtraneousComments(result);
	return result;
	}

	/**
	* At the time of this writing, the DOM Level 2 APIs are not advanced enough for setting the
	* document type; so the only parser independent way of accomplishing this is by creating a
	* stream and parsing it.
	*/
	public static InputStream createHeaderInputStream(String doctype, String publicId, String systemId) {
	return createHeaderInputStream(doctype, publicId, systemId, false);
	}



	private static InputStream createHeaderInputStream(String doctype, String publicId, String systemId, boolean includeDummy) {
	ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

	// The prior code (which is still in the catch block), uses
	// the system default encoding [System.getProperty("file.encoding")];
	// on Z/OS this is Cp1047. The combination of "UTF-8" in the header
	// and "Cp1047" in the writer create an unusable input stream.

	PrintWriter writer;

	try {
	OutputStreamWriter outputWriter = new OutputStreamWriter(outputStream, "UTF-8"); //$NON-NLS-1$
	// throws UnsupportedEncodingException
	writer = new PrintWriter(outputWriter);
	} catch (UnsupportedEncodingException e) {
	// Should never get here (earlier code)
	writer = new PrintWriter(outputStream);
	}

	writeHeader(writer, doctype, publicId, systemId);
	if (includeDummy)
	addDummyEntity(writer);
	writer.flush();
	writer.close();

	byte[] bytes = outputStream.toByteArray();
	return new ByteArrayInputStream(bytes);
	}


	private static void writeHeader(PrintWriter writer, String doctype, String publicId, String systemId) {
	writer.write("<?xml version=\""); //$NON-NLS-1$
	writer.write("1.0"); //$NON-NLS-1$
	writer.write("\" encoding=\""); //$NON-NLS-1$
	writer.write("UTF-8"); //$NON-NLS-1$
	writer.write("\"?>"); //$NON-NLS-1$
	writer.println();

	if (doctype != null) {
	writer.write("<!DOCTYPE "); //$NON-NLS-1$
	writer.write(doctype);
	writer.write(" PUBLIC \""); //$NON-NLS-1$
	writer.write(publicId);
	writer.write("\" \""); //$NON-NLS-1$
	writer.write(systemId);
	writer.write("\">"); //$NON-NLS-1$
	writer.println();
	}
	}

	private static void addDummyEntity(PrintWriter writer) {
	Revisit.revisit();
	writer.println(DUMMY_ENTITY_NODE_STRING);
	//Major hack because we can not parse an empty document
	}

	private static void removeDummyEntity(Document doc) {
	doc.removeChild(getNodeChild(doc, DUMMY_ENTITY_STRING));
	}

	private static void removeExtraneousComments(Document doc) {
	//another major hack because of a bug in XML4J 4.0.7 that added all the
	//comments from the dtd to the document. Can be removed after we move up
	//Xerces levels
	Node aNode = doc.getFirstChild();
	while (aNode != null) {
	Node nextNode = aNode.getNextSibling();
	if (aNode.getNodeType() == Node.COMMENT_NODE)
	doc.removeChild(aNode);
	aNode = nextNode;
	}
	}

	/**
	* For performance, cache a static instance of the JAXP registered document builder. Validation
	* is disabled for this instance. If you need validation, use
	* {@link #newDefaultDocumentBuilder(boolean, boolean, boolean)}
	*
	* @return DocumentBuilder
	* @throws ParserConfigurationException
	* if JAXP is not configured correctly
	*/
	public static DocumentBuilder getDefaultDocumentBuilder() throws ParserConfigurationException {
	if (defaultDocumentBuilder == null) {
	DOMLoadOptions opts = new DOMLoadOptions();
	opts.setAllowJavaEncodings(true);
	opts.setExpandEntityRefererences(true);
	opts.setValidate(false);
	defaultDocumentBuilder = newDefaultDocumentBuilder(opts);
	defaultDocumentBuilder.setEntityResolver(defaultEntityResolver);
	defaultDocumentBuilder.setErrorHandler(new ErrorHandler() {
	/*
	* (non-Javadoc)
	*
	* @see org.xml.sax.ErrorHandler#error(org.xml.sax.SAXParseException)
	*/
	public void error(SAXParseException exception) throws SAXException {

	}

	/*
	* (non-Javadoc)
	*
	* @see org.xml.sax.ErrorHandler#fatalError(org.xml.sax.SAXParseException)
	*/
	public void fatalError(SAXParseException exception) throws SAXException {

	}

	/*
	* (non-Javadoc)
	*
	* @see org.xml.sax.ErrorHandler#warning(org.xml.sax.SAXParseException)
	*/
	public void warning(SAXParseException exception) throws SAXException {

	}

	});
	}

	return defaultDocumentBuilder;
	}

	/**
	* @return
	*/
	public static EntityResolver getDefaultEntityResolver() {
	return defaultEntityResolver;
	}

	/**
	* @param resolver
	*/
	public static void setDefaultEntityResolver(EntityResolver resolver) {
	defaultEntityResolver = resolver;
	}

	}