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Java > Open Source Codes > org > jdom > contrib > input > scanner > JakartaRegExpXPathMatcher


1 /*--
2
3  $Id: JakartaRegExpXPathMatcher.java,v 1.4 2004/02/06 09:57:48 jhunter Exp $
4
5  Copyright (C) 2001-2004 Jason Hunter & Brett McLaughlin.
6  All rights reserved.
7
8  Redistribution and use in source and binary forms, with or without
9  modification, are permitted provided that the following conditions
10  are met:
11
12  1. Redistributions of source code must retain the above copyright
13     notice, this list of conditions, and the following disclaimer.
14
15  2. Redistributions in binary form must reproduce the above copyright
16     notice, this list of conditions, and the disclaimer that follows
17     these conditions in the documentation and/or other materials
18     provided with the distribution.
19
20  3. The name "JDOM" must not be used to endorse or promote products
21     derived from this software without prior written permission. For
22     written permission, please contact <request_AT_jdom_DOT_org>.
23
24  4. Products derived from this software may not be called "JDOM", nor
25     may "JDOM" appear in their name, without prior written permission
26     from the JDOM Project Management <request_AT_jdom_DOT_org>.
27
28  In addition, we request (but do not require) that you include in the
29  end-user documentation provided with the redistribution and/or in the
30  software itself an acknowledgement equivalent to the following:
31      "This product includes software developed by the
32       JDOM Project (http://www.jdom.org/)."
33  Alternatively, the acknowledgment may be graphical using the logos
34  available at http://www.jdom.org/images/logos.
35
36  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
37  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
38  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
39  DISCLAIMED. IN NO EVENT SHALL THE JDOM AUTHORS OR THE PROJECT
40  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
43  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
44  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47  SUCH DAMAGE.
48
49  This software consists of voluntary contributions made by many
50  individuals on behalf of the JDOM Project and was originally
51  created by Jason Hunter <jhunter_AT_jdom_DOT_org> and
52  Brett McLaughlin <brett_AT_jdom_DOT_org>. For more information
53  on the JDOM Project, please see <http://www.jdom.org/>.
54
55  */
56
57 package org.jdom.contrib.input.scanner;
58
59
60 import org.jdom.Element;
61 import org.jdom.JDOMException;
62 import org.jdom.xpath.XPath;
63
64 import org.xml.sax.Attributes JavaDoc;
65
66 import org.apache.regexp.RE;
67 import org.apache.regexp.RESyntaxException;
68
69
70 /* package */ class JakartaRegExpXPathMatcher extends XPathMatcher {
71
72    /**
73     * The compiled regular expression this matcher matches.
74     */
75    private final RE re;
76
77    private final XPath test;
78
79    /**
80     * Creates a new XPath matcher using Jakarta RegExp regular
81     * expression matcher implementation.
82     *
83     * @param expression the XPath-like expression to match.
84     * @param listener the element listener to notify when an
85     * element matches the expression.
86     *
87     * @throws JDOMException if one of the arguments is invalid.
88     */
89    public JakartaRegExpXPathMatcher(
90                                 String JavaDoc expression, ElementListener listener)
91                                                         throws JDOMException {
92       super(expression, listener);
93
94       try {
95          String JavaDoc pathPattern = getPathPatternAsRE(expression);
96
97          this.re = new RE(pathPattern);
98
99          String JavaDoc testPattern = getTestPattern(expression);
100          if (testPattern != null) {
101             testPattern = "." + testPattern;
102
103             this.test = XPath.newInstance(testPattern);
104          }
105          else {
106             this.test = null;
107          }
108
109          if (isDebug()) {
110             System.out.println("Listener " + listener + ":");
111             System.out.println(" " + expression +
112                                         " -> RE = " + pathPattern);
113             System.out.println(" " + expression +
114                                         " -> XPath = " + testPattern);
115          }
116       }
117       catch (RESyntaxException ex1) {
118          throw (new JDOMException(
119                         "Illegal XPath expression: " + expression, ex1));
120       }
121    }
122
123    /**
124     * Tries to match an element path and attributes with the XPath
125     * expression this matcher matches.
126     * <p>
127     * This method is invoked when processing the
128     * <code>startElement</code> SAX event.</p>
129     * <p>
130     * This implementation only matches the element path, ignoring
131     * the attributes.</p>
132     *
133     * @param path the path to the element.
134     * @param attrs the SAX attributes of the element.
135     *
136     * @return <code>true</code> is the element matches the XPath
137     * expression, <code>false</code> otherwise.
138     */
139    public boolean match(String JavaDoc path, Attributes JavaDoc attrs) {
140       return (this.re.match(path));
141    }
142
143    /**
144     * Tries to match an element with the XPath expression this
145     * matcher matches.
146     * <p>
147     * This method is invoked when processing the
148     * <code>endElement</code> SAX event. It allows matching on
149     * data not part of the <code>startElement</code> event such
150     * as the presence of child elements.</p>
151     * <p>
152     * This implementation always return <code>true</code> as it
153     * does not support matching on anything but the path.</p>
154     *
155     * @param path the path to the element.
156     * @param elt the JDOM element.
157     *
158     * @return <code>true</code> is the element matches the XPath
159     * expression, <code>false</code> otherwise.
160     */
161    public boolean match(String JavaDoc path, Element elt) {
162       if (this.test != null) {
163          boolean match = false;
164
165          try {
166             match = (this.test.selectNodes(elt).size() != 0);
167          }
168          catch (Exception JavaDoc ex1) {
169             ex1.printStackTrace();
170          }
171          return (match);
172       }
173       else {
174          return (true);
175       }
176    }
177 }
178
179
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