Back to index...

	/*
	* 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.
	*/
	package com.sun.org.apache.xml.internal.security.utils;

	import java.util.Iterator;
	import java.util.Objects;

	import javax.xml.namespace.NamespaceContext;

	import org.w3c.dom.Node;

	import static javax.xml.XMLConstants.DEFAULT_NS_PREFIX;
	import static javax.xml.XMLConstants.NULL_NS_URI;
	import static javax.xml.XMLConstants.XMLNS_ATTRIBUTE;
	import static javax.xml.XMLConstants.XMLNS_ATTRIBUTE_NS_URI;
	import static javax.xml.XMLConstants.XML_NS_PREFIX;
	import static javax.xml.XMLConstants.XML_NS_URI;

	/**
	* This class adapts the {@link Node} namespace/prefix lookup API to that of {@link NamespaceContext}.
	* There are some differences:
	* <table>
	* <tr>
	* <th>Function</th>
	* <th>{@link NamespaceContext} API</th>
	* <th>{@link Node} API</th>
	* </tr>
	* <tr>
	* <td>Look up the prefix for a given namespace URI.</td>
	* <td>{@link NamespaceContext#getPrefix(String)}</td>
	* <td>{@link Node#lookupPrefix(String)}</td>
	* </tr>
	* <tr>
	* <td>Look up all the prefixes for a given namespace URI.</td>
	* <td>{@link NamespaceContext#getPrefixes(String)}</td>
	* <td>/</td>
	* </tr>
	* <tr>
	* <td>Look up the namespace URI for a given prefix.</td>
	* <td>{@link NamespaceContext#getNamespaceURI(String)}</td>
	* <td>{@link Node#lookupNamespaceURI(String)}</td>
	* </tr>
	* <tr>
	* <td>The default prefix.</td>
	* <td>{@link javax.xml.XMLConstants#DEFAULT_NS_PREFIX}</td>
	* <td>{@code null}</td>
	* </tr>
	* <tr>
	* <td>The default namespace URI.</td>
	* <td>{@link javax.xml.XMLConstants#NULL_NS_URI}</td>
	* <td>{@code null}</td>
	* </tr>
	* </table>
	*/
	public class DOMNamespaceContext implements NamespaceContext {

	private Node context;

	public DOMNamespaceContext(Node context) {
	setContext(context);
	}

	public void setContext(Node context) {
	this.context = context;
	}

	public String getNamespaceURI(String prefix) {
	if (prefix == null) {
	throw new IllegalArgumentException("prefix is null");
	}
	if (prefix.equals(DEFAULT_NS_PREFIX)) {
	prefix = null;
	}
	if (context != null) {
	String namespaceURI = context.lookupNamespaceURI(prefix);
	if (namespaceURI != null) {
	return namespaceURI;
	}
	}
	if (prefix == null) {
	return NULL_NS_URI;
	} else if (prefix.equals(XML_NS_PREFIX)) {
	return XML_NS_URI;
	} else if (prefix.equals(XMLNS_ATTRIBUTE)) {
	return XMLNS_ATTRIBUTE_NS_URI;
	}
	return NULL_NS_URI;
	}

	public String getPrefix(String namespaceURI) {
	if (namespaceURI == null) {
	throw new IllegalArgumentException("namespace URI is null");
	}
	if (namespaceURI.equals(NULL_NS_URI)) {
	namespaceURI = null;
	}
	if (context != null) {
	String prefix = context.lookupPrefix(namespaceURI);
	if (prefix != null) {
	return prefix;
	} else if (Objects.equals(context.lookupNamespaceURI(null), namespaceURI)) {
	// context.lookupPrefix(namespaceURI) returns null when a namespace URI is unbound but also when it is
	// bound to the default prefix.
	// To distinguish the case of an unbound namespace URI from a bound one to the default prefix,
	// we look up the namespace URI for the default prefix (null) and if it matches, we return the default
	// prefix.
	return DEFAULT_NS_PREFIX;
	}
	}
	if (namespaceURI == null) {
	return context.lookupNamespaceURI(null) != null ? null : DEFAULT_NS_PREFIX;
	} else if (namespaceURI.equals(XML_NS_URI)) {
	return XML_NS_PREFIX;
	} else if (namespaceURI.equals(XMLNS_ATTRIBUTE_NS_URI)) {
	return XMLNS_ATTRIBUTE;
	}
	return null;
	}

	/**
	* Throws {@link UnsupportedOperationException}.
	*/
	public Iterator<String> getPrefixes(String namespaceURI) {
	throw new UnsupportedOperationException();
	}
	}

Back to index...