KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > jaxen > DefaultNavigator


1 /*
2  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/DefaultNavigator.java,v 1.16 2005/05/30 12:48:38 elharo Exp $
3  * $Revision: 1.16 $
4  * $Date: 2005/05/30 12:48:38 $
5  *
6  * ====================================================================
7  *
8  * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  *
15  * 1. Redistributions of source code must retain the above copyright
16  * notice, this list of conditions, and the following disclaimer.
17  *
18  * 2. Redistributions in binary form must reproduce the above copyright
19  * notice, this list of conditions, and the disclaimer that follows
20  * these conditions in the documentation and/or other materials
21  * provided with the distribution.
22  *
23  * 3. The name "Jaxen" must not be used to endorse or promote products
24  * derived from this software without prior written permission. For
25  * written permission, please contact license@jaxen.org.
26  *
27  * 4. Products derived from this software may not be called "Jaxen", nor
28  * may "Jaxen" appear in their name, without prior written permission
29  * from the Jaxen Project Management (pm@jaxen.org).
30  *
31  * In addition, we request (but do not require) that you include in the
32  * end-user documentation provided with the redistribution and/or in the
33  * software itself an acknowledgement equivalent to the following:
34  * "This product includes software developed by the
35  * Jaxen Project (http://www.jaxen.org/)."
36  * Alternatively, the acknowledgment may be graphical using the logos
37  * available at http://www.jaxen.org/
38  *
39  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
40  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42  * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
43  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
45  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
46  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
47  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
48  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
49  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * ====================================================================
53  * This software consists of voluntary contributions made by many
54  * individuals on behalf of the Jaxen Project and was originally
55  * created by bob mcwhirter <bob@werken.com> and
56  * James Strachan <jstrachan@apache.org>. For more information on the
57  * Jaxen Project, please see <http://www.jaxen.org/>.
58  *
59  * $Id: DefaultNavigator.java,v 1.16 2005/05/30 12:48:38 elharo Exp $
60  */
61
62
63
64 package org.jaxen;
65
66 import java.util.Iterator JavaDoc;
67
68 import org.jaxen.pattern.Pattern;
69 import org.jaxen.util.AncestorAxisIterator;
70 import org.jaxen.util.AncestorOrSelfAxisIterator;
71 import org.jaxen.util.DescendantAxisIterator;
72 import org.jaxen.util.DescendantOrSelfAxisIterator;
73 import org.jaxen.util.FollowingAxisIterator;
74 import org.jaxen.util.FollowingSiblingAxisIterator;
75 import org.jaxen.util.PrecedingAxisIterator;
76 import org.jaxen.util.PrecedingSiblingAxisIterator;
77 import org.jaxen.util.SelfAxisIterator;
78
79 /** Default implementation of {@link Navigator}.
80  *
81  * <p>
82  * This implementation is an abstract class, since
83  * some required operations cannot be implemented without
84  * additional knowledge of the object model.
85  * </p>
86  *
87  * <p>
88  * When possible, default method implementations build
89  * upon each other, to reduce the number of methods required
90  * to be implemented for each object model. All methods,
91  * of course, may be overridden, to provide more-efficient
92  * implementations.
93  * </p>
94  *
95  * @author bob mcwhirter (bob@werken.com)
96  * @author Erwin Bolwidt (ejb@klomp.org)
97  */
98 public abstract class DefaultNavigator implements Navigator
99 {
100
101     /** Throws <code>UnsupportedAxisException</code>
102      *
103      * @param contextNode
104      * @return never returns
105      * @throws UnsupportedAxisException always
106      */
107     public Iterator JavaDoc getChildAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
108     {
109         throw new UnsupportedAxisException("child");
110     }
111
112     /* (non-Javadoc)
113      * @see org.jaxen.Navigator#getDescendantAxisIterator(java.lang.Object)
114      */
115     public Iterator JavaDoc getDescendantAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
116     {
117         return new DescendantAxisIterator( contextNode,
118                                            this );
119     }
120
121     /** Throws <code>UnsupportedAxisException</code>
122      *
123      * @param contextNode
124      * @return never returns
125      * @throws UnsupportedAxisException
126      */
127     public Iterator JavaDoc getParentAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
128     {
129         throw new UnsupportedAxisException("parent");
130     }
131
132     public Iterator JavaDoc getAncestorAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
133     {
134         return new AncestorAxisIterator( contextNode,
135                                          this );
136     }
137
138
139     public Iterator JavaDoc getFollowingSiblingAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
140     {
141         return new FollowingSiblingAxisIterator( contextNode,
142                                                  this );
143     }
144
145
146     public Iterator JavaDoc getPrecedingSiblingAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
147     {
148         return new PrecedingSiblingAxisIterator( contextNode,
149                                                  this );
150     }
151
152     public Iterator JavaDoc getFollowingAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
153     {
154         return new FollowingAxisIterator( contextNode,
155                                           this );
156
157         // throw new UnsupportedAxisException("following");
158 }
159
160
161     public Iterator JavaDoc getPrecedingAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
162     {
163         return new PrecedingAxisIterator( contextNode,
164                                          this );
165
166         // throw new UnsupportedAxisException("preceding");
167 }
168
169     /** Throws <code>UnsupportedAxisException</code>. Subclasses that
170      * support the attribute axis must override this method.
171      *
172      * @param contextNode
173      * @return never returns
174      * @throws UnsupportedAxisException
175      */
176     public Iterator JavaDoc getAttributeAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
177     {
178         throw new UnsupportedAxisException("attribute");
179     }
180
181     /** Throws <code>UnsupportedAxisException</code>. Subclasses that
182      * support the namespace axis must override this method.
183      *
184      * @param contextNode
185      * @return never returns
186      * @throws UnsupportedAxisException
187      */
188     public Iterator JavaDoc getNamespaceAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
189     {
190         throw new UnsupportedAxisException("namespace");
191     }
192
193     public Iterator JavaDoc getSelfAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
194     {
195         return new SelfAxisIterator( contextNode );
196     }
197
198     public Iterator JavaDoc getDescendantOrSelfAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
199     {
200         return new DescendantOrSelfAxisIterator( contextNode,
201                                                  this );
202     }
203
204     public Iterator JavaDoc getAncestorOrSelfAxisIterator(Object JavaDoc contextNode) throws UnsupportedAxisException
205     {
206         return new AncestorOrSelfAxisIterator( contextNode,
207                                                this );
208     }
209
210     public Object JavaDoc getDocumentNode(Object JavaDoc contextNode)
211     {
212         return null;
213     }
214     
215     public String JavaDoc translateNamespacePrefixToUri(String JavaDoc prefix, Object JavaDoc element)
216     {
217         return null;
218     }
219
220     public String JavaDoc getProcessingInstructionTarget(Object JavaDoc obj)
221     {
222         return null;
223     }
224
225     public String JavaDoc getProcessingInstructionData(Object JavaDoc obj)
226     {
227         return null;
228     }
229
230     public short getNodeType(Object JavaDoc node)
231     {
232         if ( isElement(node) )
233         {
234             return Pattern.ELEMENT_NODE;
235         }
236         else if ( isAttribute(node) )
237         {
238             return Pattern.ATTRIBUTE_NODE;
239         }
240         else if ( isText(node) )
241         {
242             return Pattern.TEXT_NODE;
243         }
244         else if ( isComment(node) )
245         {
246             return Pattern.COMMENT_NODE;
247         }
248         else if ( isDocument(node) )
249         {
250             return Pattern.DOCUMENT_NODE;
251         }
252         else if ( isProcessingInstruction(node) )
253         {
254             return Pattern.PROCESSING_INSTRUCTION_NODE;
255         }
256         else if ( isNamespace(node) )
257         {
258             return Pattern.NAMESPACE_NODE;
259         }
260         else {
261             return Pattern.UNKNOWN_NODE;
262         }
263     }
264     
265     /**
266      * Default implementation that cannot find parent. Subclasses for
267      * models with parent should override this method.
268      *
269      * @param contextNode the node whose parent to return
270      * @return null
271      * @throws UnsupportedAxisException if the parent axis is not supported
272      */
273     public Object JavaDoc getParentNode(Object JavaDoc contextNode) throws UnsupportedAxisException
274     {
275         Iterator JavaDoc iter = getParentAxisIterator( contextNode );
276         if ( iter != null && iter.hasNext() )
277         {
278             return iter.next();
279         }
280         return null;
281     }
282
283     /**
284      * Default implementation that always returns null. Override in subclass
285      * if the subclass can load documents.
286      *
287      * @param url the URL of the document to load
288      *
289      * @return null
290      * @throws FunctionCallException if an error occurs while loading the
291      * URL; e.g. an I/O error or the document is malformed
292      */
293     public Object JavaDoc getDocument(String JavaDoc url) throws FunctionCallException
294     {
295         return null;
296     }
297
298     /**
299      * Default implementation that cannot find elements. Override in subclass
300      * if subclass does know about attribute types.
301      *
302      * @param contextNode a node from the document in which to look for the
303      * id
304      * @param elementId id to look for
305      *
306      * @return null
307      */
308     public Object JavaDoc getElementById(Object JavaDoc contextNode, String JavaDoc elementId)
309     {
310         return null;
311     }
312     
313 }
314
Popular Tags