1 /***
2 * Redistribution and use of this software and associated documentation
3 * ("Software"), with or without modification, are permitted provided
4 * that the following conditions are met:
5 *
6 * 1. Redistributions of source code must retain copyright
7 * statements and notices. Redistributions must also contain a
8 * copy of this document.
9 *
10 * 2. Redistributions in binary form must reproduce the
11 * above copyright notice, this list of conditions and the
12 * following disclaimer in the documentation and/or other
13 * materials provided with the distribution.
14 *
15 * 3. The name "Exolab" must not be used to endorse or promote
16 * products derived from this Software without prior written
17 * permission of Exoffice Technologies. For written permission,
18 * please contact info@exolab.org.
19 *
20 * 4. Products derived from this Software may not be called "Exolab"
21 * nor may "Exolab" appear in their names without prior written
22 * permission of Exoffice Technologies. Exolab is a registered
23 * trademark of Exoffice Technologies.
24 *
25 * 5. Due credit should be given to the Exolab Project
26 * (http://www.exolab.org/).
27 *
28 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
32 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39 * OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Copyright 2000-2001,2003 (C) Exoffice Technologies Inc. All Rights Reserved.
42 */
43
44 package org.exolab.jms.selector;
45
46 import org.apache.oro.text.regex.MalformedPatternException;
47 import org.apache.oro.text.regex.Pattern;
48 import org.apache.oro.text.regex.Perl5Compiler;
49
50
51 /***
52 * Regular expression factory. This creates a regular expression for a given
53 * SQL92 pattern and escape character.
54 *
55 * @version $Revision: 1.1 $ $Date: 2004/11/26 01:50:44 $
56 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
57 */
58 final class RegexpFactory {
59
60 /***
61 * Private constructor
62 */
63 private RegexpFactory() {
64 }
65
66 /***
67 * Converts the pattern and escape to an ORO <code>Pattern</code>
68 *
69 * @param pattern the pattern
70 * @param escape the escape character. May be null
71 * @return an ORO <code>Pattern</code> corresponding to
72 * <code>pattern</code> and <code>escape</code>
73 * @throws InvalidRegexpException if <code>pattern</code> or
74 * <code>escape</code> are invalid
75 */
76 public static Pattern create(final String pattern, final Character escape)
77 throws InvalidRegexpException {
78 StringBuffer buff = new StringBuffer();
79 buff.append('^');
80
81 for (int i = 0; i < pattern.length(); ++i) {
82 boolean escaped = false;
83 char ch = pattern.charAt(i);
84 if (escape != null && ch == escape.charValue()) {
85 if (++i < pattern.length()) {
86 ch = pattern.charAt(i);
87 escaped = true;
88 } else {
89 throw new InvalidRegexpException(pattern);
90 }
91 }
92
93 switch (ch) {
94 case '_':
95 if (escaped) {
96 buff.append(ch);
97 } else {
98 buff.append('.');
99 }
100 break;
101 case '%':
102 if (escaped) {
103 buff.append(ch);
104 } else {
105 buff.append(".*");
106 }
107 break;
108 case '.':
109 case '[':
110 case ']':
111 case '//':
112 case '+':
113 case '?':
114 case '{':
115 case '}':
116 case '$':
117 case '^':
118 case '|':
119 case '(':
120 case ')':
121
122
123 buff.append('//');
124 buff.append(ch);
125 break;
126 default:
127 buff.append(ch);
128 }
129 }
130 buff.append('$');
131
132 Pattern result = null;
133 try {
134 Perl5Compiler compiler = new Perl5Compiler();
135 result = compiler.compile(buff.toString());
136 } catch (MalformedPatternException exception) {
137
138 throw new InvalidRegexpException(pattern);
139 }
140 return result;
141 }
142
143 }