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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 java.util.HashSet; 47 48 import org.exolab.jms.selector.parser.SelectorTokenTypes; 49 50 51 /*** 52 * Default implementation of {@link ExpressionFactory} 53 * 54 * @version $Revision: 1.4 $ $Date: 2003/08/09 15:49:50 $ 55 * @author <a href="mailto:tma@netspacce.net.au">Tim Anderson</a> 56 * @see ExpressionFactory 57 * @see SelectorTokenTypes 58 */ 59 public final class DefaultExpressionFactory implements ExpressionFactory { 60 61 /*** 62 * Create a binary operator expression 63 * 64 * @param operator the operator token type from SelectorTokenTypes 65 * @param left the left-hand side of the binary expression 66 * @param right the right-hand side of the binary expression 67 * @return a new binary expression 68 * @throws SelectorException if the operator is not a valid binary operator 69 */ 70 public Expression binaryOperator(final int operator, final Expression left, 71 final Expression right) 72 throws SelectorException { 73 74 Expression result = null; 75 switch (operator) { 76 case SelectorTokenTypes.LITERAL_and: 77 result = new And(left, right); 78 break; 79 case SelectorTokenTypes.LITERAL_or: 80 result = new Or(left, right); 81 break; 82 case SelectorTokenTypes.EQUAL: 83 result = new Equal(left, right); 84 break; 85 case SelectorTokenTypes.NOT_EQUAL: 86 result = new NotEqual(left, right); 87 break; 88 case SelectorTokenTypes.LT: 89 result = new Less(left, right); 90 break; 91 case SelectorTokenTypes.GT: 92 result = new Greater(left, right); 93 break; 94 case SelectorTokenTypes.LE: 95 result = new LessEqual(left, right); 96 break; 97 case SelectorTokenTypes.GE: 98 result = new GreaterEqual(left, right); 99 break; 100 case SelectorTokenTypes.PLUS: 101 result = new Add(left, right); 102 break; 103 case SelectorTokenTypes.MINUS: 104 result = new Subtract(left, right); 105 break; 106 case SelectorTokenTypes.MULTIPLY: 107 result = new Multiply(left, right); 108 break; 109 case SelectorTokenTypes.DIVIDE: 110 result = new Divide(left, right); 111 break; 112 default: 113 throw new SelectorException("Unknown binary operator type: " 114 + operator); 115 } 116 return result; 117 } 118 119 /*** 120 * Create an unary operator expression 121 * 122 * @param operator the operator token type from SelectorTokenTypes 123 * @param operand the expression to apply the operator to 124 * @return a new unary expression 125 * @throws SelectorException if the operator is not a valid unary operator 126 */ 127 public Expression unaryOperator(final int operator, 128 final Expression operand) 129 throws SelectorException { 130 Expression result = null; 131 switch (operator) { 132 case SelectorTokenTypes.LITERAL_not: 133 result = new Not(operand); 134 break; 135 case SelectorTokenTypes.UNARY_MINUS: 136 result = new UnaryMinus(operand); 137 break; 138 default: 139 throw new SelectorException("Unknown unary operator type: " 140 + operator); 141 } 142 return result; 143 } 144 145 /*** 146 * Create an identifier expression 147 * 148 * @param name the name of the identifier 149 * @return a new identifier expression 150 * @throws SelectorException is name is not a valid identifier 151 */ 152 public Expression identifier(final String name) throws SelectorException { 153 return new Identifier(name); 154 } 155 156 /*** 157 * Create an 'is null' expression 158 * 159 * @param identifier the identifer expression to apply the 'is null' test 160 * @return an 'is null' expression 161 * @throws SelectorException for any error 162 */ 163 public Expression isNull(final Expression identifier) 164 throws SelectorException { 165 return new IsExpression((Identifier) identifier); 166 } 167 168 /*** 169 * Create a 'like' expression 170 * 171 * @param identifier the identifer to apply the 'like' test to 172 * @param pattern the search pattern 173 * @param escape the escape character. This may be null 174 * @return a new 'like' expression 175 * @throws SelectorException if the pattern or escape is invalid 176 */ 177 public Expression like(final Expression identifier, final String pattern, 178 final String escape) throws SelectorException { 179 return new LikeExpression((Identifier) identifier, pattern, escape); 180 } 181 182 /*** 183 * Create a 'between' expression that returns the result of:<br/> 184 * <code>num1 >= num2 and num1 <= num3</code> 185 * when evaluated 186 * 187 * @param num1 an arithmethic expression 188 * @param num2 an arithmethic expression 189 * @param num3 an arithmethic expression 190 * @return a new 'between' expression 191 * @throws SelectorException for any error 192 */ 193 public Expression between(final Expression num1, final Expression num2, 194 final Expression num3) throws SelectorException { 195 return new BetweenExpression(num1, num2, num3); 196 } 197 198 /*** 199 * Create an 'in' expression 200 * 201 * @param identifier string identifer to apply the 'in' test to 202 * @param set the set of string values to compare against 203 * @return a new 'in' expression 204 * @throws SelectorException for any error 205 */ 206 public Expression in(final Expression identifier, final HashSet set) 207 throws SelectorException { 208 return new InExpression((Identifier) identifier, set); 209 } 210 211 /*** 212 * Create a literal expression 213 * 214 * @param type the operator token type from SelectorTokenTypes 215 * @param text the literal text 216 * @return a new literal expression 217 * @throws SelectorException if type is not a valid literal type 218 */ 219 public Expression literal(final int type, final String text) 220 throws SelectorException { 221 Expression result = null; 222 switch (type) { 223 case SelectorTokenTypes.NUM_FLOAT: 224 result = Literal.approxNumericLiteral(text); 225 break; 226 case SelectorTokenTypes.NUM_INT: 227 result = Literal.exactNumericLiteral(text); 228 break; 229 case SelectorTokenTypes.STRING_LITERAL: 230 result = Literal.stringLiteral(text); 231 break; 232 case SelectorTokenTypes.LITERAL_true: 233 result = Literal.booleanLiteral(true); 234 break; 235 case SelectorTokenTypes.LITERAL_false: 236 result = Literal.booleanLiteral(false); 237 break; 238 default: 239 throw new SelectorException("Unknown literal type: " + type); 240 } 241 242 return result; 243 } 244 245 } //-- DefaultExpressionFactory

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