diff options
Diffstat (limited to 'java/broker/src/main/java/org/apache/qpid/server/filter/ArithmeticExpression.java')
-rw-r--r-- | java/broker/src/main/java/org/apache/qpid/server/filter/ArithmeticExpression.java | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/java/broker/src/main/java/org/apache/qpid/server/filter/ArithmeticExpression.java b/java/broker/src/main/java/org/apache/qpid/server/filter/ArithmeticExpression.java new file mode 100644 index 0000000000..0aa5739c1c --- /dev/null +++ b/java/broker/src/main/java/org/apache/qpid/server/filter/ArithmeticExpression.java @@ -0,0 +1,216 @@ +/** + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.qpid.server.filter; +// +// Based on like named file from r450141 of the Apache ActiveMQ project <http://www.activemq.org/site/home.html> +// + + +import org.apache.qpid.server.queue.AMQMessage; + +import javax.jms.JMSException; + +/** + * An expression which performs an operation on two expression values + * + * @version $Revision$ + */ +public abstract class ArithmeticExpression extends BinaryExpression { + + protected static final int INTEGER = 1; + protected static final int LONG = 2; + protected static final int DOUBLE = 3; + + /** + * @param left + * @param right + */ + public ArithmeticExpression(Expression left, Expression right) { + super(left, right); + } + + public static Expression createPlus(Expression left, Expression right) { + return new ArithmeticExpression(left, right) { + protected Object evaluate(Object lvalue, Object rvalue) { + if (lvalue instanceof String) { + String text = (String) lvalue; + String answer = text + rvalue; + return answer; + } + else if (lvalue instanceof Number) { + return plus((Number) lvalue, asNumber(rvalue)); + } + throw new RuntimeException("Cannot call plus operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() { + return "+"; + } + }; + } + + public static Expression createMinus(Expression left, Expression right) { + return new ArithmeticExpression(left, right) { + protected Object evaluate(Object lvalue, Object rvalue) { + if (lvalue instanceof Number) { + return minus((Number) lvalue, asNumber(rvalue)); + } + throw new RuntimeException("Cannot call minus operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() { + return "-"; + } + }; + } + + public static Expression createMultiply(Expression left, Expression right) { + return new ArithmeticExpression(left, right) { + + protected Object evaluate(Object lvalue, Object rvalue) { + if (lvalue instanceof Number) { + return multiply((Number) lvalue, asNumber(rvalue)); + } + throw new RuntimeException("Cannot call multiply operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() { + return "*"; + } + }; + } + + public static Expression createDivide(Expression left, Expression right) { + return new ArithmeticExpression(left, right) { + + protected Object evaluate(Object lvalue, Object rvalue) { + if (lvalue instanceof Number) { + return divide((Number) lvalue, asNumber(rvalue)); + } + throw new RuntimeException("Cannot call divide operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() { + return "/"; + } + }; + } + + public static Expression createMod(Expression left, Expression right) { + return new ArithmeticExpression(left, right) { + + protected Object evaluate(Object lvalue, Object rvalue) { + if (lvalue instanceof Number) { + return mod((Number) lvalue, asNumber(rvalue)); + } + throw new RuntimeException("Cannot call mod operation on: " + lvalue + " and: " + rvalue); + } + + public String getExpressionSymbol() { + return "%"; + } + }; + } + + protected Number plus(Number left, Number right) { + switch (numberType(left, right)) { + case INTEGER: + return new Integer(left.intValue() + right.intValue()); + case LONG: + return new Long(left.longValue() + right.longValue()); + default: + return new Double(left.doubleValue() + right.doubleValue()); + } + } + + protected Number minus(Number left, Number right) { + switch (numberType(left, right)) { + case INTEGER: + return new Integer(left.intValue() - right.intValue()); + case LONG: + return new Long(left.longValue() - right.longValue()); + default: + return new Double(left.doubleValue() - right.doubleValue()); + } + } + + protected Number multiply(Number left, Number right) { + switch (numberType(left, right)) { + case INTEGER: + return new Integer(left.intValue() * right.intValue()); + case LONG: + return new Long(left.longValue() * right.longValue()); + default: + return new Double(left.doubleValue() * right.doubleValue()); + } + } + + protected Number divide(Number left, Number right) { + return new Double(left.doubleValue() / right.doubleValue()); + } + + protected Number mod(Number left, Number right) { + return new Double(left.doubleValue() % right.doubleValue()); + } + + private int numberType(Number left, Number right) { + if (isDouble(left) || isDouble(right)) { + return DOUBLE; + } + else if (left instanceof Long || right instanceof Long) { + return LONG; + } + else { + return INTEGER; + } + } + + private boolean isDouble(Number n) { + return n instanceof Float || n instanceof Double; + } + + protected Number asNumber(Object value) { + if (value instanceof Number) { + return (Number) value; + } + else { + throw new RuntimeException("Cannot convert value: " + value + " into a number"); + } + } + + public Object evaluate(AMQMessage message) throws JMSException { + Object lvalue = left.evaluate(message); + if (lvalue == null) { + return null; + } + Object rvalue = right.evaluate(message); + if (rvalue == null) { + return null; + } + return evaluate(lvalue, rvalue); + } + + + /** + * @param lvalue + * @param rvalue + * @return + */ + abstract protected Object evaluate(Object lvalue, Object rvalue); + +} |