001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.jxpath.ri.model.dom;
018    
019    import org.apache.commons.jxpath.ri.Compiler;
020    import org.apache.commons.jxpath.ri.QName;
021    import org.apache.commons.jxpath.ri.compiler.NodeTest;
022    import org.apache.commons.jxpath.ri.compiler.NodeTypeTest;
023    import org.apache.commons.jxpath.ri.model.NodePointer;
024    
025    /**
026     * Represents a namespace node.
027     *
028     * @author Dmitri Plotnikov
029     * @version $Revision: 652884 $ $Date: 2008-05-02 15:02:00 -0500 (Fri, 02 May 2008) $
030     */
031    public class NamespacePointer extends NodePointer {
032        private String prefix;
033        private String namespaceURI;
034    
035        private static final long serialVersionUID = -7622456151550131709L;
036    
037        /**
038         * Create a new NamespacePointer.
039         * @param parent parent pointer
040         * @param prefix associated ns prefix.
041         */
042        public NamespacePointer(NodePointer parent, String prefix) {
043            super(parent);
044            this.prefix = prefix;
045        }
046    
047        /**
048         * Create a new NamespacePointer.
049         * @param parent parent pointer
050         * @param prefix associated ns prefix.
051         * @param namespaceURI associated ns URI.
052         */
053        public NamespacePointer(
054            NodePointer parent,
055            String prefix,
056            String namespaceURI) {
057            super(parent);
058            this.prefix = prefix;
059            this.namespaceURI = namespaceURI;
060        }
061    
062        public QName getName() {
063            return new QName(prefix);
064        }
065    
066        public Object getBaseValue() {
067            return null;
068        }
069    
070        public boolean isCollection() {
071            return false;
072        }
073    
074        public int getLength() {
075            return 1;
076        }
077    
078        public Object getImmediateNode() {
079            return getNamespaceURI();
080        }
081    
082        public String getNamespaceURI() {
083            if (namespaceURI == null) {
084                namespaceURI = parent.getNamespaceURI(prefix);
085            }
086            return namespaceURI;
087        }
088    
089        public boolean isLeaf() {
090            return true;
091        }
092    
093        /**
094         * Throws UnsupportedOperationException.
095         * @param value Object
096         */
097        public void setValue(Object value) {
098            throw new UnsupportedOperationException("Cannot modify DOM trees");
099        }
100    
101        public boolean testNode(NodeTest nodeTest) {
102            return nodeTest == null
103                || ((nodeTest instanceof NodeTypeTest)
104                    && ((NodeTypeTest) nodeTest).getNodeType()
105                        == Compiler.NODE_TYPE_NODE);
106        }
107    
108        public String asPath() {
109            StringBuffer buffer = new StringBuffer();
110            if (parent != null) {
111                buffer.append(parent.asPath());
112                if (buffer.length() == 0
113                    || buffer.charAt(buffer.length() - 1) != '/') {
114                    buffer.append('/');
115                }
116            }
117            buffer.append("namespace::");
118            buffer.append(prefix);
119            return buffer.toString();
120        }
121    
122        public int hashCode() {
123            return prefix.hashCode();
124        }
125    
126        public boolean equals(Object object) {
127            if (object == this) {
128                return true;
129            }
130    
131            if (!(object instanceof NamespacePointer)) {
132                return false;
133            }
134    
135            NamespacePointer other = (NamespacePointer) object;
136            return prefix.equals(other.prefix);
137        }
138    
139        public int compareChildNodePointers(
140            NodePointer pointer1,
141            NodePointer pointer2) {
142            // Won't happen - namespaces don't have children
143            return 0;
144        }
145    }