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	/*
	* reserved comment block
	* DO NOT REMOVE OR ALTER!
	*/
	/**
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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.
	*/
	/*
	* Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
	*/
	package org.jcp.xml.dsig.internal.dom;

	import java.security.spec.AlgorithmParameterSpec;
	import java.util.List;

	import javax.xml.XMLConstants;
	import javax.xml.crypto.MarshalException;
	import javax.xml.crypto.XMLCryptoContext;
	import javax.xml.crypto.XMLStructure;
	import javax.xml.crypto.dsig.XMLSignature;
	import javax.xml.crypto.dsig.spec.ExcC14NParameterSpec;
	import javax.xml.crypto.dsig.spec.XPathFilter2ParameterSpec;
	import javax.xml.crypto.dsig.spec.XPathFilterParameterSpec;
	import javax.xml.crypto.dsig.spec.XPathType;
	import javax.xml.crypto.dsig.spec.XSLTTransformParameterSpec;

	import org.w3c.dom.Attr;
	import org.w3c.dom.Document;
	import org.w3c.dom.Element;
	import org.w3c.dom.Node;

	/**
	* Useful static DOM utility methods.
	*
	*/
	public final class DOMUtils {

	// class cannot be instantiated
	private DOMUtils() {}

	/**
	* Returns the owner document of the specified node.
	*
	* @param node the node
	* @return the owner document
	*/
	public static Document getOwnerDocument(Node node) {
	if (node.getNodeType() == Node.DOCUMENT_NODE) {
	return (Document)node;
	} else {
	return node.getOwnerDocument();
	}
	}

	/**
	* Create a QName string from a prefix and local name.
	*
	* @param prefix The prefix, if any. Can be either null or empty.
	* @param localName The local name.
	*
	* @return The string for the qName, for example, "xsd:element".
	*/
	public static String getQNameString(String prefix, String localName) {
	String qName = prefix == null \|\| prefix.length() == 0
	? localName : prefix + ":" + localName;

	return qName;
	}

	/**
	* Creates an element in the specified namespace, with the specified tag
	* and namespace prefix.
	*
	* @param doc the owner document
	* @param tag the tag
	* @param nsURI the namespace URI
	* @param prefix the namespace prefix
	* @return the newly created element
	*/
	public static Element createElement(Document doc, String tag,
	String nsURI, String prefix)
	{
	String qName = (prefix == null \|\| prefix.length() == 0)
	? tag : prefix + ":" + tag;
	return doc.createElementNS(nsURI, qName);
	}

	/**
	* Sets an element's attribute (using DOM level 2) with the
	* specified value and namespace prefix.
	*
	* @param elem the element to set the attribute on
	* @param name the name of the attribute
	* @param value the attribute value. If null, no attribute is set.
	*/
	public static void setAttribute(Element elem, String name, String value) {
	if (value == null) {
	return;
	}
	elem.setAttributeNS(null, name, value);
	}

	/**
	* Sets an element's attribute (using DOM level 2) with the
	* specified value and namespace prefix AND registers the ID value with
	* the specified element. This is for resolving same-document
	* ID references.
	*
	* @param elem the element to set the attribute on
	* @param name the name of the attribute
	* @param value the attribute value. If null, no attribute is set.
	*/
	public static void setAttributeID(Element elem, String name, String value) {
	if (value == null) {
	return;
	}
	elem.setAttributeNS(null, name, value);
	elem.setIdAttributeNS(null, name, true);
	}

	/**
	* Returns the first child element of the specified node, or null if there
	* is no such element.
	*
	* @param node the node
	* @return the first child element of the specified node, or null if there
	* is no such element
	* @throws NullPointerException if {@code node == null}
	*/
	public static Element getFirstChildElement(Node node) {
	Node child = node.getFirstChild();
	while (child != null && child.getNodeType() != Node.ELEMENT_NODE) {
	child = child.getNextSibling();
	}
	return (Element)child;
	}

	/**
	* Returns the first child element of the specified node and checks that
	* the local name is equal to {@code localName} and the namespace is equal to
	* {@code namespaceURI}
	*
	* @param node the node
	* @return the first child element of the specified node
	* @throws NullPointerException if {@code node == null}
	* @throws MarshalException if no such element or the local name is not
	* equal to {@code localName}
	*/
	public static Element getFirstChildElement(Node node, String localName, String namespaceURI)
	throws MarshalException
	{
	return verifyElement(getFirstChildElement(node), localName, namespaceURI);
	}

	private static Element verifyElement(Element elem, String localName, String namespaceURI)
	throws MarshalException
	{
	if (elem == null) {
	throw new MarshalException("Missing " + localName + " element");
	}
	String name = elem.getLocalName();
	String namespace = elem.getNamespaceURI();
	if (!name.equals(localName) \|\| namespace == null && namespaceURI != null
	\|\| namespace != null && !namespace.equals(namespaceURI)) {
	throw new MarshalException("Invalid element name: " +
	namespace + ":" + name + ", expected " + namespaceURI + ":" + localName);
	}
	return elem;
	}

	/**
	* Returns the last child element of the specified node, or null if there
	* is no such element.
	*
	* @param node the node
	* @return the last child element of the specified node, or null if there
	* is no such element
	* @throws NullPointerException if {@code node == null}
	*/
	public static Element getLastChildElement(Node node) {
	Node child = node.getLastChild();
	while (child != null && child.getNodeType() != Node.ELEMENT_NODE) {
	child = child.getPreviousSibling();
	}
	return (Element)child;
	}

	/**
	* Returns the next sibling element of the specified node, or null if there
	* is no such element.
	*
	* @param node the node
	* @return the next sibling element of the specified node, or null if there
	* is no such element
	* @throws NullPointerException if {@code node == null}
	*/
	public static Element getNextSiblingElement(Node node) {
	Node sibling = node.getNextSibling();
	while (sibling != null && sibling.getNodeType() != Node.ELEMENT_NODE) {
	sibling = sibling.getNextSibling();
	}
	return (Element)sibling;
	}

	/**
	* Returns the next sibling element of the specified node and checks that
	* the local name is equal to {@code localName} and the namespace is equal to
	* {@code namespaceURI}
	*
	* @param node the node
	* @return the next sibling element of the specified node
	* @throws NullPointerException if {@code node == null}
	* @throws MarshalException if no such element or the local name is not
	* equal to {@code localName}
	*/
	public static Element getNextSiblingElement(Node node, String localName, String namespaceURI)
	throws MarshalException
	{
	return verifyElement(getNextSiblingElement(node), localName, namespaceURI);
	}

	/**
	* Returns the attribute value for the attribute with the specified name.
	* Returns null if there is no such attribute, or
	* the empty string if the attribute value is empty.
	*
	* <p>This works around a limitation of the DOM
	* {@code Element.getAttributeNode} method, which does not distinguish
	* between an unspecified attribute and an attribute with a value of
	* "" (it returns "" for both cases).
	*
	* @param elem the element containing the attribute
	* @param name the name of the attribute
	* @return the attribute value (may be null if unspecified)
	*/
	public static String getAttributeValue(Element elem, String name) {
	Attr attr = elem.getAttributeNodeNS(null, name);
	return (attr == null) ? null : attr.getValue();
	}

	/**
	* Returns the attribute value for the attribute with the specified name.
	* Returns null if there is no such attribute, or
	* the empty string if the attribute value is empty.
	*
	* <p>This works around a limitation of the DOM
	* {@code Element.getAttributeNode} method, which does not distinguish
	* between an unspecified attribute and an attribute with a value of
	* "" (it returns "" for both cases).
	*
	* @param elem the element containing the attribute
	* @param name the name of the attribute
	* @return the attribute value (may be null if unspecified)
	*/
	public static <N> String getIdAttributeValue(Element elem, String name) {
	Attr attr = elem.getAttributeNodeNS(null, name);
	if (attr != null && !attr.isId()) {
	elem.setIdAttributeNode(attr, true);
	}
	return (attr == null) ? null : attr.getValue();
	}

	/**
	* Returns the prefix associated with the specified namespace URI
	*
	* @param context contains the namespace map
	* @param nsURI the namespace URI
	* @return the prefix associated with the specified namespace URI, or
	* null if not set
	*/
	public static String getNSPrefix(XMLCryptoContext context, String nsURI) {
	if (context != null) {
	return context.getNamespacePrefix
	(nsURI, context.getDefaultNamespacePrefix());
	} else {
	return null;
	}
	}

	/**
	* Returns the prefix associated with the XML Signature namespace URI
	*
	* @param context contains the namespace map
	* @return the prefix associated with the specified namespace URI, or
	* null if not set
	*/
	public static String getSignaturePrefix(XMLCryptoContext context) {
	return getNSPrefix(context, XMLSignature.XMLNS);
	}

	/**
	* Removes all children nodes from the specified node.
	*
	* @param node the parent node whose children are to be removed
	*/
	public static void removeAllChildren(Node node) {
	Node firstChild = node.getFirstChild();
	while (firstChild != null) {
	Node nodeToRemove = firstChild;
	firstChild = firstChild.getNextSibling();
	node.removeChild(nodeToRemove);
	}
	}

	/**
	* Compares 2 nodes for equality.
	*/
	public static boolean nodesEqual(Node thisNode, Node otherNode) {
	return thisNode.isEqualNode(otherNode);
	}

	/**
	* Checks if child element has same owner document before
	* appending to the parent, and imports it to the parent's document
	* if necessary.
	*/
	public static void appendChild(Node parent, Node child) {
	Document ownerDoc = getOwnerDocument(parent);
	if (child.getOwnerDocument() != ownerDoc) {
	parent.appendChild(ownerDoc.importNode(child, true));
	} else {
	parent.appendChild(child);
	}
	}

	public static boolean paramsEqual(AlgorithmParameterSpec spec1,
	AlgorithmParameterSpec spec2) {
	if (spec1 == spec2) {
	return true;
	}
	if (spec1 instanceof XPathFilter2ParameterSpec &&
	spec2 instanceof XPathFilter2ParameterSpec) {
	return paramsEqual((XPathFilter2ParameterSpec)spec1,
	(XPathFilter2ParameterSpec)spec2);
	}
	if (spec1 instanceof ExcC14NParameterSpec &&
	spec2 instanceof ExcC14NParameterSpec) {
	return paramsEqual((ExcC14NParameterSpec) spec1,
	(ExcC14NParameterSpec)spec2);
	}
	if (spec1 instanceof XPathFilterParameterSpec &&
	spec2 instanceof XPathFilterParameterSpec) {
	return paramsEqual((XPathFilterParameterSpec)spec1,
	(XPathFilterParameterSpec)spec2);
	}
	if (spec1 instanceof XSLTTransformParameterSpec &&
	spec2 instanceof XSLTTransformParameterSpec) {
	return paramsEqual((XSLTTransformParameterSpec)spec1,
	(XSLTTransformParameterSpec)spec2);
	}
	return false;
	}

	private static boolean paramsEqual(XPathFilter2ParameterSpec spec1,
	XPathFilter2ParameterSpec spec2)
	{
	@SuppressWarnings("unchecked")
	List<XPathType> types = spec1.getXPathList();
	@SuppressWarnings("unchecked")
	List<XPathType> otypes = spec2.getXPathList();
	int size = types.size();
	if (size != otypes.size()) {
	return false;
	}
	for (int i = 0; i < size; i++) {
	XPathType type = types.get(i);
	XPathType otype = otypes.get(i);
	if (!type.getExpression().equals(otype.getExpression()) \|\|
	!type.getNamespaceMap().equals(otype.getNamespaceMap()) \|\|
	type.getFilter() != otype.getFilter()) {
	return false;
	}
	}
	return true;
	}

	private static boolean paramsEqual(ExcC14NParameterSpec spec1,
	ExcC14NParameterSpec spec2)
	{
	return spec1.getPrefixList().equals(spec2.getPrefixList());
	}

	private static boolean paramsEqual(XPathFilterParameterSpec spec1,
	XPathFilterParameterSpec spec2)
	{
	return spec1.getXPath().equals(spec2.getXPath()) &&
	spec1.getNamespaceMap().equals(spec2.getNamespaceMap());
	}

	private static boolean paramsEqual(XSLTTransformParameterSpec spec1,
	XSLTTransformParameterSpec spec2)
	{

	XMLStructure ostylesheet = spec2.getStylesheet();
	if (!(ostylesheet instanceof javax.xml.crypto.dom.DOMStructure)) {
	return false;
	}
	Node ostylesheetElem =
	((javax.xml.crypto.dom.DOMStructure) ostylesheet).getNode();
	XMLStructure stylesheet = spec1.getStylesheet();
	Node stylesheetElem =
	((javax.xml.crypto.dom.DOMStructure) stylesheet).getNode();
	return nodesEqual(stylesheetElem, ostylesheetElem);
	}

	public static boolean isNamespace(Node node)
	{
	if (Node.ATTRIBUTE_NODE == node.getNodeType()) {
	final String namespaceURI = node.getNamespaceURI();
	return XMLConstants.XMLNS_ATTRIBUTE_NS_URI.equals(namespaceURI);
	}
	return false;
	}
	}

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