| /** |
| * |
| * 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.AMQException; |
| import org.apache.qpid.server.queue.Filterable; |
| |
| /** |
| * An expression which performs an operation on two expression values |
| */ |
| public abstract class ArithmeticExpression<E extends Exception> extends BinaryExpression<E> |
| { |
| |
| 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(Filterable<E> message) throws E |
| { |
| 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 |
| */ |
| protected abstract Object evaluate(Object lvalue, Object rvalue); |
| |
| } |