/*
* Copyright 2002-2009 the original author or authors.
*
* Licensed 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.springframework.expression.spel.ast;
import org.springframework.expression.EvaluationException;
import org.springframework.expression.Operation;
import org.springframework.expression.TypedValue;
import org.springframework.expression.spel.ExpressionState;
/**
* Implements the multiply operator. Conversions and promotions:
* http://java.sun.com/docs/books/jls/third_edition/html/conversions.html Section 5.6.2:
*
* <p>If any of the operands is of a reference type, unboxing conversion (�5.1.8) is performed. Then:<br>
* If either operand is of type double, the other is converted to double.<br>
* Otherwise, if either operand is of type float, the other is converted to float.<br>
* Otherwise, if either operand is of type long, the other is converted to long.<br>
* Otherwise, both operands are converted to type int.
*
* <p>
*
* @author Andy Clement
* @since 3.0
*/
public class OpMultiply extends Operator {
public OpMultiply(int pos, SpelNodeImpl... operands) {
super("*", pos, operands);
}
/**
* Implements multiply directly here for some types of operand, otherwise delegates to any registered overloader for
* types it does not recognize. Supported types here are:
* <ul>
* <li>integers
* <li>doubles
* <li>string and int ('abc' * 2 == 'abcabc')
* </ul>
*/
@Override
public TypedValue getValueInternal(ExpressionState state) throws EvaluationException {
Object operandOne = getLeftOperand().getValueInternal(state).getValue();
Object operandTwo = getRightOperand().getValueInternal(state).getValue();
if (operandOne instanceof Number && operandTwo instanceof Number) {
Number leftNumber = (Number) operandOne;
Number rightNumber = (Number) operandTwo;
if (leftNumber instanceof Double || rightNumber instanceof Double) {
return new TypedValue(leftNumber.doubleValue() * rightNumber.doubleValue());
} else if (leftNumber instanceof Long || rightNumber instanceof Long) {
return new TypedValue(leftNumber.longValue() * rightNumber.longValue());
} else {
return new TypedValue(leftNumber.intValue() * rightNumber.intValue());
}
} else if (operandOne instanceof String && operandTwo instanceof Integer) {
int repeats = (Integer) operandTwo;
StringBuilder result = new StringBuilder();
for (int i = 0; i < repeats; i++) {
result.append(operandOne);
}
return new TypedValue(result.toString());
}
return state.operate(Operation.MULTIPLY, operandOne, operandTwo);
}
}
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