1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/javabean/JavaBeanXPath.java,v 1.4 2005/06/28 13:44:46 elharo Exp $
3 * $Revision: 1.4 $
4 * $Date: 2005/06/28 13:44:46 $
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: JavaBeanXPath.java,v 1.4 2005/06/28 13:44:46 elharo Exp $
60 */
61
62 package org.jaxen.javabean;
63
64 import org.jaxen.Context;
65 import org.jaxen.BaseXPath;
66 import org.jaxen.JaxenException;
67
68 import java.util.List;
69 import java.util.ArrayList;
70 import java.util.Collection;
71 import java.util.Iterator;
72
73 /*** An XPath implementation for JavaBeans.
74 *
75 * <p>This is the main entry point for matching an XPath against a JavaBean
76 * tree. You create a compiled XPath object, then match it against
77 * one or more context nodes using the {@link #selectNodes(Object)}
78 * method, as in the following example:</p>
79 *
80 * <pre>
81 * Node node = ...;
82 * XPath path = new JavaBeanXPath("a/b/c");
83 * List results = path.selectNodes(node);
84 * </pre>
85 *
86 * @see BaseXPath
87 *
88 * @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
89 *
90 * @version $Revision: 1.4 $
91 */
92 public class JavaBeanXPath extends BaseXPath
93 {
94 /*** Construct given an XPath expression string.
95 *
96 * @param xpathExpr The XPath expression.
97 *
98 * @throws JaxenException if there is a syntax error while
99 * parsing the expression
100 */
101 public JavaBeanXPath(String xpathExpr) throws JaxenException
102 {
103 super( xpathExpr, DocumentNavigator.getInstance() );
104 }
105
106 protected Context getContext(Object node)
107 {
108 if ( node instanceof Context )
109 {
110 return (Context) node;
111 }
112
113 if ( node instanceof Element )
114 {
115 return super.getContext( node );
116 }
117
118 if ( node instanceof List )
119 {
120 List newList = new ArrayList();
121
122 for ( Iterator listIter = ((List)node).iterator();
123 listIter.hasNext(); )
124 {
125 newList.add( new Element( null, "root", listIter.next() ) );
126 }
127
128 return super.getContext( newList );
129 }
130
131 return super.getContext( new Element( null, "root", node ) );
132 }
133
134 public Object evaluate(Object node)
135 throws JaxenException
136 {
137 Object result = super.evaluate( node );
138
139 if ( result instanceof Element )
140 {
141 return ((Element)result).getObject();
142 }
143 else if ( result instanceof Collection )
144 {
145 List newList = new ArrayList();
146
147 for ( Iterator listIter = ((Collection)result).iterator();
148 listIter.hasNext(); )
149 {
150 Object member = listIter.next();
151
152 if ( member instanceof Element )
153 {
154 newList.add( ((Element)member).getObject() );
155 }
156 else
157 {
158 newList.add( member );
159 }
160 }
161
162 return newList;
163 }
164
165 return result;
166 }
167 }