/*
* Copyright 2002-2015 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 java.math.BigDecimal;
import java.math.BigInteger;
import org.springframework.asm.MethodVisitor;
import org.springframework.expression.EvaluationException;
import org.springframework.expression.Operation;
import org.springframework.expression.TypedValue;
import org.springframework.expression.spel.CodeFlow;
import org.springframework.expression.spel.ExpressionState;
import org.springframework.util.NumberUtils;
/**
* Implements the {@code multiply} operator.
*
* <p>Conversions and promotions are handled as defined in
* <a href="http://java.sun.com/docs/books/jls/third_edition/html/conversions.html">Section 5.6.2 of the
* Java Language Specification</a>, with the addiction of {@code BigDecimal}/{@code BigInteger} management:
*
* <p>If any of the operands is of a reference type, unboxing conversion (Section 5.1.8)
* is performed. Then:<br>
* If either operand is of type {@code BigDecimal}, the other is converted to {@code BigDecimal}.<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>
* If either operand is of type {@code BigInteger}, the other is converted to {@code BigInteger}.<br>
* Otherwise, if either operand is of type long, the other is converted to long.<br>
* Otherwise, both operands are converted to type int.
*
* @author Andy Clement
* @author Juergen Hoeller
* @author Sam Brannen
* @author Giovanni Dall'Oglio Risso
* @since 3.0
*/
public class OpMultiply extends Operator {
public OpMultiply(int pos, SpelNodeImpl... operands) {
super("*", pos, operands);
}
/**
* Implements the {@code multiply} operator directly here for certain types
* of supported operands and otherwise delegates to any registered overloader
* for types not supported here.
* <p>Supported operand types:
* <ul>
* <li>numbers
* <li>String and int ('abc' * 2 == 'abcabc')
* </ul>
*/
@Override
public TypedValue getValueInternal(ExpressionState state) throws EvaluationException {
Object leftOperand = getLeftOperand().getValueInternal(state).getValue();
Object rightOperand = getRightOperand().getValueInternal(state).getValue();
if (leftOperand instanceof Number && rightOperand instanceof Number) {
Number leftNumber = (Number) leftOperand;
Number rightNumber = (Number) rightOperand;
if (leftNumber instanceof BigDecimal || rightNumber instanceof BigDecimal) {
BigDecimal leftBigDecimal = NumberUtils.convertNumberToTargetClass(leftNumber, BigDecimal.class);
BigDecimal rightBigDecimal = NumberUtils.convertNumberToTargetClass(rightNumber, BigDecimal.class);
return new TypedValue(leftBigDecimal.multiply(rightBigDecimal));
}
else if (leftNumber instanceof Double || rightNumber instanceof Double) {
this.exitTypeDescriptor = "D";
return new TypedValue(leftNumber.doubleValue() * rightNumber.doubleValue());
}
else if (leftNumber instanceof Float || rightNumber instanceof Float) {
this.exitTypeDescriptor = "F";
return new TypedValue(leftNumber.floatValue() * rightNumber.floatValue());
}
else if (leftNumber instanceof BigInteger || rightNumber instanceof BigInteger) {
BigInteger leftBigInteger = NumberUtils.convertNumberToTargetClass(leftNumber, BigInteger.class);
BigInteger rightBigInteger = NumberUtils.convertNumberToTargetClass(rightNumber, BigInteger.class);
return new TypedValue(leftBigInteger.multiply(rightBigInteger));
}
else if (leftNumber instanceof Long || rightNumber instanceof Long) {
this.exitTypeDescriptor = "J";
return new TypedValue(leftNumber.longValue() * rightNumber.longValue());
}
else if (CodeFlow.isIntegerForNumericOp(leftNumber) || CodeFlow.isIntegerForNumericOp(rightNumber)) {
this.exitTypeDescriptor = "I";
return new TypedValue(leftNumber.intValue() * rightNumber.intValue());
}
else {
// Unknown Number subtypes -> best guess is double multiplication
return new TypedValue(leftNumber.doubleValue() * rightNumber.doubleValue());
}
}
if (leftOperand instanceof String && rightOperand instanceof Integer) {
int repeats = (Integer) rightOperand;
StringBuilder result = new StringBuilder();
for (int i = 0; i < repeats; i++) {
result.append(leftOperand);
}
return new TypedValue(result.toString());
}
return state.operate(Operation.MULTIPLY, leftOperand, rightOperand);
}
@Override
public boolean isCompilable() {
if (!getLeftOperand().isCompilable()) {
return false;
}
if (this.children.length > 1) {
if (!getRightOperand().isCompilable()) {
return false;
}
}
return (this.exitTypeDescriptor != null);
}
@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
getLeftOperand().generateCode(mv, cf);
String leftDesc = getLeftOperand().exitTypeDescriptor;
CodeFlow.insertNumericUnboxOrPrimitiveTypeCoercion(mv, leftDesc, this.exitTypeDescriptor.charAt(0));
if (this.children.length > 1) {
cf.enterCompilationScope();
getRightOperand().generateCode(mv, cf);
String rightDesc = getRightOperand().exitTypeDescriptor;
cf.exitCompilationScope();
CodeFlow.insertNumericUnboxOrPrimitiveTypeCoercion(mv, rightDesc, this.exitTypeDescriptor.charAt(0));
switch (this.exitTypeDescriptor.charAt(0)) {
case 'I':
mv.visitInsn(IMUL);
break;
case 'J':
mv.visitInsn(LMUL);
break;
case 'F':
mv.visitInsn(FMUL);
break;
case 'D':
mv.visitInsn(DMUL);
break;
default:
throw new IllegalStateException(
"Unrecognized exit type descriptor: '" + this.exitTypeDescriptor + "'");
}
}
cf.pushDescriptor(this.exitTypeDescriptor);
}
}