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Java > Open Source Codes > org > apache > commons > jxpath > ri > model > jdom > JDOMAttributeIterator


1 /*
2  * Copyright 1999-2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.commons.jxpath.ri.model.jdom;
17
18 import java.util.ArrayList JavaDoc;
19 import java.util.Collections JavaDoc;
20 import java.util.List JavaDoc;
21
22 import org.apache.commons.jxpath.ri.QName;
23 import org.apache.commons.jxpath.ri.model.NodeIterator;
24 import org.apache.commons.jxpath.ri.model.NodePointer;
25 import org.jdom.Attribute;
26 import org.jdom.Element;
27 import org.jdom.Namespace;
28
29 /**
30  * An iterator of attributes of a DOM Node.
31  *
32  * @author Dmitri Plotnikov
33  * @version $Revision: 1.6 $ $Date: 2004/02/29 14:17:40 $
34  */
35 public class JDOMAttributeIterator implements NodeIterator {
36     private NodePointer parent;
37     private QName name;
38     private List JavaDoc attributes;
39     private int position = 0;
40
41     public JDOMAttributeIterator(NodePointer parent, QName name) {
42         this.parent = parent;
43         this.name = name;
44         if (parent.getNode() instanceof Element) {
45             Element element = (Element) parent.getNode();
46             String JavaDoc prefix = name.getPrefix();
47             Namespace ns;
48             if (prefix != null) {
49                 if (prefix.equals("xml")) {
50                     ns = Namespace.XML_NAMESPACE;
51                 }
52                 else {
53                     ns = element.getNamespace(prefix);
54                     if (ns == null) {
55                         // TBD: no attributes
56 attributes = Collections.EMPTY_LIST;
57                         return;
58                     }
59                 }
60             }
61             else {
62                 ns = Namespace.NO_NAMESPACE;
63             }
64
65             String JavaDoc lname = name.getName();
66             if (!lname.equals("*")) {
67                 attributes = new ArrayList JavaDoc();
68                 if (ns != null) {
69                     Attribute attr = element.getAttribute(lname, ns);
70                     if (attr != null) {
71                         attributes.add(attr);
72                     }
73                 }
74             }
75             else {
76                 attributes = new ArrayList JavaDoc();
77                 List JavaDoc allAttributes = element.getAttributes();
78                 for (int i = 0; i < allAttributes.size(); i++) {
79                     Attribute attr = (Attribute) allAttributes.get(i);
80                     if (attr.getNamespace().equals(ns)) {
81                         attributes.add(attr);
82                     }
83                 }
84             }
85         }
86     }
87
88     /*
89     private boolean testAttr(Attr attr, QName testName) {
90         String nodePrefix = DOMNodePointer.getPrefix(attr);
91         String nodeLocalName = DOMNodePointer.getLocalName(attr);
92
93         if (nodePrefix != null && nodePrefix.equals("xmlns")) {
94             return false;
95         }
96
97         if (nodePrefix == null && nodeLocalName.equals("xmlns")) {
98             return false;
99         }
100
101         String testLocalName = name.getName();
102         if (testLocalName.equals("*") || testLocalName.equals(nodeLocalName)) {
103             String testPrefix = testName.getPrefix();
104
105             if (equalStrings(testPrefix, nodePrefix)) {
106                 return true;
107             }
108
109             String testNS = null;
110             if (testPrefix != null) {
111                 testNS = parent.getNamespaceURI(testPrefix);
112             }
113
114             String nodeNS = null;
115             if (nodePrefix != null) {
116                 nodeNS = parent.getNamespaceURI(nodePrefix);
117             }
118             return equalStrings(testNS, nodeNS);
119         }
120         return false;
121     }
122
123     private static boolean equalStrings(String s1, String s2) {
124         if (s1 == null && s2 != null) {
125             return false;
126         }
127         if (s1 != null && !s1.equals(s2)) {
128             return false;
129         }
130         return true;
131     }
132
133     private Attr getAttribute(Element element, QName name) {
134         String testPrefix = name.getPrefix();
135         String testNS = null;
136
137         if (testPrefix != null) {
138             testNS = parent.getNamespaceURI(testPrefix);
139         }
140
141         if (testNS != null) {
142             Attr attr = element.getAttributeNodeNS(testNS, name.getName());
143             if (attr == null) {
144                 // This may mean that the parser does not support NS for
145                 // attributes, example - the version of Crimson bundled
146                 // with JDK 1.4.0
147                 NamedNodeMap nnm = element.getAttributes();
148                 for (int i = 0; i < nnm.getLength(); i++) {
149                     attr = (Attr)nnm.item(i);
150                     if (testAttr(attr, name)) {
151                         return attr;
152                     }
153                 }
154             }
155             return attr;
156         }
157         else {
158             return element.getAttributeNode(name.getName());
159         }
160     }
161 */
162     public NodePointer getNodePointer() {
163         if (position == 0) {
164             if (!setPosition(1)) {
165                 return null;
166             }
167             position = 0;
168         }
169         int index = position - 1;
170         if (index < 0) {
171             index = 0;
172         }
173         return new JDOMAttributePointer(
174             parent,
175             (Attribute) attributes.get(index));
176     }
177
178     public int getPosition() {
179         return position;
180     }
181
182     public boolean setPosition(int position) {
183         if (attributes == null) {
184             return false;
185         }
186         this.position = position;
187         return position >= 1 && position <= attributes.size();
188     }
189 }
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