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Java > Open Source Codes > org > mr > api > jms > selector > parser > PatternValidator


1 /*
2  * Copyright 2002 by
3  * <a HREF="http://www.coridan.com">Coridan</a>
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7  * 1.1 (the "License"); you may not use this file except in compliance with the
8  * License. You may obtain a copy of the License at
9  * http://www.mozilla.org/MPL/
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11  * Software distributed under the License is distributed on an "AS IS" basis,
12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
13  * for the specific language governing rights and limitations under the
14  * License.
15  *
16  * The Original Code is "MantaRay" (TM).
17  *
18  * The Initial Developer of the Original Code is Coridan.
19  * Portions created by the Initial Developer are Copyright (C) 2006
20  * Coridan Inc. All Rights Reserved.
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22  * Contributor(s): all the names of the contributors are added in the source
23  * code where applicable.
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25  * Alternatively, the contents of this file may be used under the terms of the
26  * LGPL license (the "GNU LESSER GENERAL PUBLIC LICENSE"), in which case the
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33  * of this file under either the MPL or the GNU LESSER GENERAL PUBLIC LICENSE.
34  
35  *
36  * This library is free software; you can redistribute it and/or modify it
37  * under the terms of the MPL as stated above or under the terms of the GNU
38  * Lesser General Public License as published by the Free Software Foundation;
39  * either version 2.1 of the License, or any later version.
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41  * This library is distributed in the hope that it will be useful, but WITHOUT
42  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
43  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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45  */
46 package org.mr.api.jms.selector.parser;
47
48 import org.mr.api.jms.selector.syntax.SelectorException;
49
50 /**
51  * This class validates the format of patterns and escape characters used
52  * in 'like' expressions.
53  *
54  */
55 final class PatternValidator {
56
57     /**
58      * Private constructor,we don't want to create a new instance of PatternValidator
59      */
60     private PatternValidator() {
61     }//PatternValidator
62
63     
64     /**
65      * Validate a pattern and escape
66      *
67      * @param patternNode the pattern node
68      * @param escapeNode the escape node. May be null.
69      * @throws SelectorException if the pattern or escape node are invalid
70      */
71     public static void validate(final SelectorAST patternNode, final SelectorAST escapeNode) throws SelectorException {
72
73         String JavaDoc pattern = patternNode.getText();
74
75         if (escapeNode != null) {
76             String JavaDoc escape = escapeNode.getText();
77             if (escape.length() != 1) {
78                 String JavaDoc msg = "escape must be a single character";
79                 throw new SelectorException(escapeNode.getContext(), msg);
80             }//if
81
82             char esc = escape.charAt(0);
83             for (int i = 0; i < pattern.length(); ++i) {
84                 //char ch = pattern.charAt(i);
85 if (pattern.charAt(i) == esc) {
86                     if (++i >= pattern.length()) {
87                         String JavaDoc msg = "invalid pattern: no character "
88                             + "following last escape character";
89                         throw new SelectorException(patternNode.getContext(),
90                                                     msg);
91                     }//if
92 }//if
93 }//for
94 }//if
95 }//validate
96 }//PatternValidator
97
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