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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 javax.jms.Message; 47 48 import org.apache.oro.text.regex.Pattern; 49 import org.apache.oro.text.regex.PatternMatcher; 50 import org.apache.oro.text.regex.Perl5Matcher; 51 52 53 /*** 54 * This class implements a 'like' expression. 55 * This is an expression that returns true if a identifier's value matches 56 * a pattern 57 * 58 * @version $Revision: 1.5 $ $Date: 2003/08/09 15:49:50 $ 59 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a> 60 * @see Identifier 61 * @see IdentifierExpression 62 * @see RegexpFactory 63 */ 64 class LikeExpression extends IdentifierExpression { 65 66 /*** 67 * The regular expression 68 */ 69 private final Pattern _regexp; 70 71 /*** 72 * The pattern matcher 73 */ 74 private final PatternMatcher _matcher; 75 76 /*** 77 * The pattern 78 */ 79 private final String _pattern; 80 81 /*** 82 * The escape character. May be null. 83 */ 84 private final String _escape; 85 86 87 /*** 88 * Construct a new <code>LikeExpression</code> 89 * 90 * @param identifier the identifier 91 * @param pattern the pattern 92 * @param escape the escape character. May be null. 93 * @throws SelectorException if <code>pattern</code> or <code>escape</code> 94 * are invalid 95 */ 96 public LikeExpression(final Identifier identifier, final String pattern, 97 final String escape) throws SelectorException { 98 super(identifier); 99 _pattern = pattern; 100 _escape = escape; 101 _regexp = getRegexp(_pattern, _escape); 102 _matcher = new Perl5Matcher(); 103 } 104 105 /*** 106 * Evaluate the expression 107 * 108 * @param msg the message to use to obtain any header identifier and 109 * property values 110 * @return the evaluated result, or <code>null</code> if the value of the 111 * expression is unknown 112 * @throws TypeMismatchException if the expression tries to evaluate 113 * mismatched types. 114 */ 115 public final SObject evaluate(final Message msg) 116 throws TypeMismatchException { 117 SBool result = null; 118 SString value = TypeCaster.castToString(identifier().evaluate(msg), 119 "like expression"); 120 if (value != null) { 121 if (_matcher.matches((String) value.getObject(), _regexp)) { 122 result = SBool.TRUE; 123 } else { 124 result = SBool.FALSE; 125 } 126 } 127 return result; 128 } 129 130 /*** 131 * Return a string representation of this expression. 132 * 133 * @return a string representation of this expression 134 */ 135 public final String toString() { 136 StringBuffer result = new StringBuffer(); 137 result.append('('); 138 result.append(identifier().toString()); 139 result.append(" like '"); 140 result.append(_pattern); 141 result.append('\''); 142 if (_escape != null) { 143 result.append(" escape '"); 144 result.append(_escape); 145 result.append('\''); 146 } 147 result.append(')'); 148 return result.toString(); 149 } 150 151 /*** 152 * Converts the pattern and escape to an ORO <code>Pattern</code> 153 * 154 * @param pattern the pattern 155 * @param escape the escape character. May be null 156 * @return an ORO <code>Pattern</code> corresponding to 157 * <code>pattern</code> and <code>escape</code> 158 * @throws SelectorException if <code>pattern</code> or <code>escape</code> 159 * are invalid 160 */ 161 private Pattern getRegexp(final String pattern, final String escape) 162 throws SelectorException { 163 Pattern result = null; 164 Character esc = null; 165 166 if (escape != null) { 167 if (escape.length() != 1) { 168 throw new SelectorException("Invalid escape: " + escape); 169 } 170 esc = new Character(escape.charAt(0)); 171 } 172 173 try { 174 result = RegexpFactory.create(pattern, esc); 175 } catch (InvalidRegexpException err) { 176 throw new SelectorException("Invalid pattern: " + pattern); 177 } 178 return result; 179 } 180 181 } //-- LikeExpression

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