001/**
002 * Copyright 2005-2016 The Kuali Foundation
003 *
004 * Licensed under the Educational Community License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.opensource.org/licenses/ecl2.php
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.kuali.rice.ken.util;
017
018import java.util.ArrayList;
019import java.util.Iterator;
020import java.util.List;
021
022import javax.xml.namespace.NamespaceContext;
023
024import org.apache.log4j.Logger;
025import org.w3c.dom.Document;
026
027/**
028 * XPath NamespaceContext implementation that delegates all lookups to a DOM Document,
029 * which supplies all prefix/NS mappings defined in the doc.
030 * @author Kuali Rice Team (rice.collab@kuali.org)
031 */
032public class DocumentNamespaceContext implements NamespaceContext {
033    private static final Logger LOG = Logger.getLogger(DocumentNamespaceContext.class);
034
035    // the DOM Document
036    private final Document doc;
037
038    /**
039     * Constructs a DocumentNamespaceContext.java.
040     * @param doc
041     */
042    public DocumentNamespaceContext(Document doc) {
043        this.doc = doc;
044    }
045
046    /**
047     * @see javax.xml.namespace.NamespaceContext#getNamespaceURI(java.lang.String)
048     */
049    public String getNamespaceURI(String prefix) {
050        LOG.debug("getNamespaceURI(" + prefix + ")");
051        if (prefix == null) {
052            throw new IllegalArgumentException("The prefix cannot be null.");
053        }
054        if (prefix.length() == 0) {
055            return doc.lookupNamespaceURI(null);
056        }
057        return doc.lookupNamespaceURI(prefix);
058    }
059
060    /**
061     * @see javax.xml.namespace.NamespaceContext#getPrefix(java.lang.String)
062     */
063    public String getPrefix(String namespaceURI) {
064        LOG.debug("getPrefix(" + namespaceURI + ")");
065        if (namespaceURI == null) {
066            throw new IllegalArgumentException("The namespace uri cannot be null.");
067        }
068        return doc.lookupPrefix(namespaceURI);
069    }
070
071    /**
072     * @see javax.xml.namespace.NamespaceContext#getPrefixes(java.lang.String)
073     */
074    public Iterator getPrefixes(String namespaceURI) {
075        LOG.debug("getPrefixes(" + namespaceURI + ")");
076        if (namespaceURI == null) {
077            throw new IllegalArgumentException("The namespace uri cannot be null.");
078        }
079        List<String> list = new ArrayList<String>(1);
080        String s = getPrefix(namespaceURI);
081        if (s != null) {
082            list.add(s);
083        }
084        return list.iterator();
085    }
086}