001/**
002 * Copyright 2005-2017 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
024/**
025 * XPath NamespaceContext implementation that delegates in sequence to a list of NamespaceContexts,
026 * returning the first match. 
027 * @author Kuali Rice Team (rice.collab@kuali.org)
028 */
029public class CompoundNamespaceContext implements NamespaceContext {
030    private final List<NamespaceContext> contexts;
031
032    /**
033     * Constructs a CompoundNamespaceContext.java.
034     * @param first
035     * @param second
036     */
037    public CompoundNamespaceContext(NamespaceContext first, NamespaceContext second) {
038        this.contexts = new ArrayList<NamespaceContext>(2);
039        this.contexts.add(first);
040        this.contexts.add(second);
041    }
042    
043    /**
044     * Constructs a CompoundNamespaceContext.java.
045     * @param contexts
046     */
047    public CompoundNamespaceContext(List<NamespaceContext> contexts) {
048        this.contexts = contexts;
049    }
050
051    /**
052     * @see javax.xml.namespace.NamespaceContext#getNamespaceURI(java.lang.String)
053     */
054    public String getNamespaceURI(String prefix) {
055        if (prefix == null) {
056            throw new IllegalArgumentException("The prefix cannot be null.");
057        }
058        for (NamespaceContext nc: contexts) {
059            String uri = nc.getNamespaceURI(prefix);
060            if (uri != null) {
061                return uri;
062            }
063        }
064        return null;
065    }
066
067    /**
068     * @see javax.xml.namespace.NamespaceContext#getPrefix(java.lang.String)
069     */
070    public String getPrefix(String namespaceURI) {
071        if (namespaceURI == null) {
072            throw new IllegalArgumentException("The namespace uri cannot be null.");
073        }
074        for (NamespaceContext nc: contexts) {
075            String prefix = nc.getPrefix(namespaceURI);
076            if (prefix != null) {
077                return prefix;
078            }
079        }
080        return null;
081    }
082
083    /**
084     * @see javax.xml.namespace.NamespaceContext#getPrefixes(java.lang.String)
085     */
086    public Iterator getPrefixes(String namespaceURI) {
087        if (namespaceURI == null) {
088            throw new IllegalArgumentException("The namespace uri cannot be null.");
089        }
090        for (NamespaceContext nc: contexts) {
091            Iterator prefixes = nc.getPrefixes(namespaceURI);
092            if (prefixes != null) {
093                return prefixes;
094            }
095        }
096        return null;
097    }
098}