1 /*
2 * Copyright 2000-2002 bob mcwhirter & James Strachan.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met:
8 *
9 * * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * * Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * * Neither the name of the Jaxen Project nor the names of its
17 * contributors may be used to endorse or promote products derived
18 * from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
21 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
23 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
24 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 *
32 * ====================================================================
33 * This software consists of voluntary contributions made by many
34 * individuals on behalf of the Jaxen Project and was originally
35 * created by bob mcwhirter <bob@werken.com> and
36 * James Strachan <jstrachan@apache.org>. For more information on the
37 * Jaxen Project, please see <http://www.jaxen.org/>.
38 *
39 */
40
41 package org.jaxen.javabean;
42
43 import org.jaxen.Context;
44 import org.jaxen.BaseXPath;
45 import org.jaxen.JaxenException;
46
47 import java.util.List;
48 import java.util.ArrayList;
49 import java.util.Collection;
50 import java.util.Iterator;
51
52 /** An XPath implementation for JavaBeans.
53 *
54 * <p>This is the main entry point for matching an XPath against a JavaBean
55 * tree. You create a compiled XPath object, then match it against
56 * one or more context nodes using the {@link #selectNodes(Object)}
57 * method, as in the following example:</p>
58 *
59 * <pre>
60 * Node node = ...;
61 * XPath path = new JavaBeanXPath("a/b/c");
62 * List results = path.selectNodes(node);
63 * </pre>
64 *
65 * @see BaseXPath
66 *
67 * @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
68 *
69 */
70 public class JavaBeanXPath extends BaseXPath
71 {
72
73 private static final long serialVersionUID = -1567521943360266313L;
74
75 /** Construct given an XPath expression string.
76 *
77 * @param xpathExpr the XPath expression
78 *
79 * @throws JaxenException if there is a syntax error while
80 * parsing the expression
81 */
82 public JavaBeanXPath(String xpathExpr) throws JaxenException
83 {
84 super( xpathExpr, DocumentNavigator.getInstance() );
85 }
86
87 @Override
88 protected Context getContext(Object node)
89 {
90 if ( node instanceof Context )
91 {
92 return (Context) node;
93 }
94
95 if ( node instanceof Element )
96 {
97 return super.getContext( node );
98 }
99
100 if ( node instanceof List )
101 {
102 List<Element> newList = new ArrayList<Element>();
103
104 for ( Iterator listIter = ((List)node).iterator();
105 listIter.hasNext(); )
106 {
107 newList.add( new Element( null, "root", listIter.next() ) );
108 }
109
110 return super.getContext( newList );
111 }
112
113 return super.getContext( new Element( null, "root", node ) );
114 }
115
116 @Override
117 public Object evaluate(Object node)
118 throws JaxenException
119 {
120 Object result = super.evaluate( node );
121
122 if ( result instanceof Element )
123 {
124 return ((Element)result).getObject();
125 }
126 else if ( result instanceof Collection )
127 {
128 List<Object> newList = new ArrayList<Object>();
129
130 for ( Iterator<Object> listIter = ((Collection)result).iterator();
131 listIter.hasNext(); )
132 {
133 Object member = listIter.next();
134
135 if ( member instanceof Element )
136 {
137 newList.add( ((Element)member).getObject() );
138 }
139 else
140 {
141 newList.add( member );
142 }
143 }
144
145 return newList;
146 }
147
148 return result;
149 }
150 }