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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 49 /*** 50 * This class implements a literal expression. 51 * 52 * @version $Revision: 1.8 $ $Date: 2003/08/09 15:49:50 $ 53 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a> 54 * @see Expression 55 */ 56 class Literal implements Expression { 57 58 /*** 59 * The literal value 60 */ 61 private SObject _value = null; 62 63 /*** 64 * Construct a new <code>Literal</code> expression 65 * 66 * @param value the value of the literal 67 */ 68 protected Literal(final SObject value) { 69 _value = value; 70 } 71 72 /*** 73 * Construct an approximate numeric literal expression 74 * 75 * @param text the literal text 76 * @return an approximate numeric literal expression 77 * @throws SelectorException if <code>text</code> is not a valid 78 * approximate numeric literal 79 */ 80 public static Literal approxNumericLiteral(final String text) 81 throws SelectorException { 82 SDouble value = null; 83 try { 84 value = new SDouble(Double.parseDouble(text)); 85 } catch (NumberFormatException exception) { 86 throw new SelectorException("invalid float: " + text); 87 } 88 return new Literal(value); 89 } 90 91 /*** 92 * Construct an exact numeric literal expression 93 * 94 * @param text the literal text 95 * @return an exact numeric literal expression 96 * @throws SelectorException if <code>text</code> is not a valid exact 97 * numeric literal 98 */ 99 public static Literal exactNumericLiteral(final String text) 100 throws SelectorException { 101 SLong value = null; 102 try { 103 value = new SLong(Long.decode(text).longValue()); 104 } catch (NumberFormatException exception) { 105 throw new SelectorException("invalid integer: " + text); 106 } 107 return new Literal(value); 108 } 109 110 /*** 111 * Construct a string literal expression 112 * 113 * @param text the literal text 114 * @return a string literal expression 115 */ 116 public static Literal stringLiteral(final String text) { 117 return new Literal(new SString(text)) { 118 119 public final String toString() { 120 return "'" + this.getValue().toString() + "'"; 121 } 122 }; 123 } 124 125 /*** 126 * Construct a boolean literal expression 127 * 128 * @param value the boolean literal value 129 * @return a boolean literal expression 130 */ 131 public static Literal booleanLiteral(final boolean value) { 132 SBool bool = SBool.FALSE; 133 if (value) { 134 bool = SBool.TRUE; 135 } 136 return new Literal(bool); 137 } 138 139 /*** 140 * Evaluate the expression 141 * 142 * @param msg the message to use to obtain any header identifier and 143 * property values 144 * @return the evaluated result, or <code>null</code> if the value of the 145 * expression is unknown 146 */ 147 public final SObject evaluate(final Message msg) { 148 return _value; 149 } 150 151 /*** 152 * Return a string representation of the literal 153 * 154 * @return a string representation of the literal 155 */ 156 public String toString() { 157 return getValue().toString(); 158 } 159 160 /*** 161 * Returns the value of the literal 162 * 163 * @return the value of the literal 164 */ 165 protected final SObject getValue() { 166 return _value; 167 } 168 169 } //-- Literal

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