001 /**
002 * GRANITE DATA SERVICES
003 * Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004 *
005 * This file is part of the Granite Data Services Platform.
006 *
007 * Granite Data Services is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * Granite Data Services is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015 * General Public License for more details.
016 *
017 * You should have received a copy of the GNU Lesser General Public
018 * License along with this library; if not, write to the Free Software
019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020 * USA, or see <http://www.gnu.org/licenses/>.
021 */
022 package org.granite.gravity.selector;
023
024 import javax.jms.JMSException;
025
026 /**
027 * An expression which performs an operation on two expression values
028 *
029 * @version $Revision: 1.2 $
030 */
031 public abstract class ArithmeticExpression extends BinaryExpression {
032
033 protected static final int INTEGER = 1;
034 protected static final int LONG = 2;
035 protected static final int DOUBLE = 3;
036
037 /**
038 * @param left
039 * @param right
040 */
041 public ArithmeticExpression(Expression left, Expression right) {
042 super(left, right);
043 }
044
045 public static Expression createPlus(Expression left, Expression right) {
046 return new ArithmeticExpression(left, right) {
047 @Override
048 protected Object evaluate(Object lvalue, Object rvalue) {
049 if (lvalue instanceof String) {
050 String text = (String) lvalue;
051 String answer = text + rvalue;
052 return answer;
053 }
054 else if (lvalue instanceof Number) {
055 return plus((Number) lvalue, asNumber(rvalue));
056 }
057 throw new RuntimeException("Cannot call plus operation on: " + lvalue + " and: " + rvalue);
058 }
059
060 @Override
061 public String getExpressionSymbol() {
062 return "+";
063 }
064 };
065 }
066
067 public static Expression createMinus(Expression left, Expression right) {
068 return new ArithmeticExpression(left, right) {
069 @Override
070 protected Object evaluate(Object lvalue, Object rvalue) {
071 if (lvalue instanceof Number) {
072 return minus((Number) lvalue, asNumber(rvalue));
073 }
074 throw new RuntimeException("Cannot call minus operation on: " + lvalue + " and: " + rvalue);
075 }
076
077 @Override
078 public String getExpressionSymbol() {
079 return "-";
080 }
081 };
082 }
083
084 public static Expression createMultiply(Expression left, Expression right) {
085 return new ArithmeticExpression(left, right) {
086
087 @Override
088 protected Object evaluate(Object lvalue, Object rvalue) {
089 if (lvalue instanceof Number) {
090 return multiply((Number) lvalue, asNumber(rvalue));
091 }
092 throw new RuntimeException("Cannot call multiply operation on: " + lvalue + " and: " + rvalue);
093 }
094
095 @Override
096 public String getExpressionSymbol() {
097 return "*";
098 }
099 };
100 }
101
102 public static Expression createDivide(Expression left, Expression right) {
103 return new ArithmeticExpression(left, right) {
104
105 @Override
106 protected Object evaluate(Object lvalue, Object rvalue) {
107 if (lvalue instanceof Number) {
108 return divide((Number) lvalue, asNumber(rvalue));
109 }
110 throw new RuntimeException("Cannot call divide operation on: " + lvalue + " and: " + rvalue);
111 }
112
113 @Override
114 public String getExpressionSymbol() {
115 return "/";
116 }
117 };
118 }
119
120 public static Expression createMod(Expression left, Expression right) {
121 return new ArithmeticExpression(left, right) {
122
123 @Override
124 protected Object evaluate(Object lvalue, Object rvalue) {
125 if (lvalue instanceof Number) {
126 return mod((Number) lvalue, asNumber(rvalue));
127 }
128 throw new RuntimeException("Cannot call mod operation on: " + lvalue + " and: " + rvalue);
129 }
130
131 @Override
132 public String getExpressionSymbol() {
133 return "%";
134 }
135 };
136 }
137
138 protected Number plus(Number left, Number right) {
139 switch (numberType(left, right)) {
140 case INTEGER:
141 return new Integer(left.intValue() + right.intValue());
142 case LONG:
143 return new Long(left.longValue() + right.longValue());
144 default:
145 return new Double(left.doubleValue() + right.doubleValue());
146 }
147 }
148
149 protected Number minus(Number left, Number right) {
150 switch (numberType(left, right)) {
151 case INTEGER:
152 return new Integer(left.intValue() - right.intValue());
153 case LONG:
154 return new Long(left.longValue() - right.longValue());
155 default:
156 return new Double(left.doubleValue() - right.doubleValue());
157 }
158 }
159
160 protected Number multiply(Number left, Number right) {
161 switch (numberType(left, right)) {
162 case INTEGER:
163 return new Integer(left.intValue() * right.intValue());
164 case LONG:
165 return new Long(left.longValue() * right.longValue());
166 default:
167 return new Double(left.doubleValue() * right.doubleValue());
168 }
169 }
170
171 protected Number divide(Number left, Number right) {
172 return new Double(left.doubleValue() / right.doubleValue());
173 }
174
175 protected Number mod(Number left, Number right) {
176 return new Double(left.doubleValue() % right.doubleValue());
177 }
178
179 private int numberType(Number left, Number right) {
180 if (isDouble(left) || isDouble(right)) {
181 return DOUBLE;
182 }
183 else if (left instanceof Long || right instanceof Long) {
184 return LONG;
185 }
186 else {
187 return INTEGER;
188 }
189 }
190
191 private boolean isDouble(Number n) {
192 return n instanceof Float || n instanceof Double;
193 }
194
195 protected Number asNumber(Object value) {
196 if (value instanceof Number) {
197 return (Number) value;
198 }
199 throw new RuntimeException("Cannot convert value: " + value + " into a number");
200 }
201
202 public Object evaluate(MessageEvaluationContext message) throws JMSException {
203 Object lvalue = left.evaluate(message);
204 if (lvalue == null) {
205 return null;
206 }
207 Object rvalue = right.evaluate(message);
208 if (rvalue == null) {
209 return null;
210 }
211 return evaluate(lvalue, rvalue);
212 }
213
214
215 /**
216 * @param lvalue
217 * @param rvalue
218 * @return the evaluated value
219 */
220 abstract protected Object evaluate(Object lvalue, Object rvalue);
221
222 }