001/* 002 * Copyright 2002-2019 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.expression.spel.ast; 018 019import java.math.BigDecimal; 020import java.math.BigInteger; 021 022import org.springframework.asm.MethodVisitor; 023import org.springframework.expression.EvaluationException; 024import org.springframework.expression.Operation; 025import org.springframework.expression.TypedValue; 026import org.springframework.expression.spel.CodeFlow; 027import org.springframework.expression.spel.ExpressionState; 028import org.springframework.util.Assert; 029import org.springframework.util.NumberUtils; 030 031/** 032 * Implements the {@code multiply} operator. 033 * 034 * <p>Conversions and promotions are handled as defined in 035 * <a href="https://java.sun.com/docs/books/jls/third_edition/html/conversions.html">Section 5.6.2 of the 036 * Java Language Specification</a>, with the addiction of {@code BigDecimal}/{@code BigInteger} management: 037 * 038 * <p>If any of the operands is of a reference type, unboxing conversion (Section 5.1.8) 039 * is performed. Then:<br> 040 * If either operand is of type {@code BigDecimal}, the other is converted to {@code BigDecimal}.<br> 041 * If either operand is of type double, the other is converted to double.<br> 042 * Otherwise, if either operand is of type float, the other is converted to float.<br> 043 * If either operand is of type {@code BigInteger}, the other is converted to {@code BigInteger}.<br> 044 * Otherwise, if either operand is of type long, the other is converted to long.<br> 045 * Otherwise, both operands are converted to type int. 046 * 047 * @author Andy Clement 048 * @author Juergen Hoeller 049 * @author Sam Brannen 050 * @author Giovanni Dall'Oglio Risso 051 * @since 3.0 052 */ 053public class OpMultiply extends Operator { 054 055 public OpMultiply(int startPos, int endPos, SpelNodeImpl... operands) { 056 super("*", startPos, endPos, operands); 057 } 058 059 060 /** 061 * Implements the {@code multiply} operator directly here for certain types 062 * of supported operands and otherwise delegates to any registered overloader 063 * for types not supported here. 064 * <p>Supported operand types: 065 * <ul> 066 * <li>numbers 067 * <li>String and int ('abc' * 2 == 'abcabc') 068 * </ul> 069 */ 070 @Override 071 public TypedValue getValueInternal(ExpressionState state) throws EvaluationException { 072 Object leftOperand = getLeftOperand().getValueInternal(state).getValue(); 073 Object rightOperand = getRightOperand().getValueInternal(state).getValue(); 074 075 if (leftOperand instanceof Number && rightOperand instanceof Number) { 076 Number leftNumber = (Number) leftOperand; 077 Number rightNumber = (Number) rightOperand; 078 079 if (leftNumber instanceof BigDecimal || rightNumber instanceof BigDecimal) { 080 BigDecimal leftBigDecimal = NumberUtils.convertNumberToTargetClass(leftNumber, BigDecimal.class); 081 BigDecimal rightBigDecimal = NumberUtils.convertNumberToTargetClass(rightNumber, BigDecimal.class); 082 return new TypedValue(leftBigDecimal.multiply(rightBigDecimal)); 083 } 084 else if (leftNumber instanceof Double || rightNumber instanceof Double) { 085 this.exitTypeDescriptor = "D"; 086 return new TypedValue(leftNumber.doubleValue() * rightNumber.doubleValue()); 087 } 088 else if (leftNumber instanceof Float || rightNumber instanceof Float) { 089 this.exitTypeDescriptor = "F"; 090 return new TypedValue(leftNumber.floatValue() * rightNumber.floatValue()); 091 } 092 else if (leftNumber instanceof BigInteger || rightNumber instanceof BigInteger) { 093 BigInteger leftBigInteger = NumberUtils.convertNumberToTargetClass(leftNumber, BigInteger.class); 094 BigInteger rightBigInteger = NumberUtils.convertNumberToTargetClass(rightNumber, BigInteger.class); 095 return new TypedValue(leftBigInteger.multiply(rightBigInteger)); 096 } 097 else if (leftNumber instanceof Long || rightNumber instanceof Long) { 098 this.exitTypeDescriptor = "J"; 099 return new TypedValue(leftNumber.longValue() * rightNumber.longValue()); 100 } 101 else if (CodeFlow.isIntegerForNumericOp(leftNumber) || CodeFlow.isIntegerForNumericOp(rightNumber)) { 102 this.exitTypeDescriptor = "I"; 103 return new TypedValue(leftNumber.intValue() * rightNumber.intValue()); 104 } 105 else { 106 // Unknown Number subtypes -> best guess is double multiplication 107 return new TypedValue(leftNumber.doubleValue() * rightNumber.doubleValue()); 108 } 109 } 110 111 if (leftOperand instanceof String && rightOperand instanceof Integer) { 112 int repeats = (Integer) rightOperand; 113 StringBuilder result = new StringBuilder(); 114 for (int i = 0; i < repeats; i++) { 115 result.append(leftOperand); 116 } 117 return new TypedValue(result.toString()); 118 } 119 120 return state.operate(Operation.MULTIPLY, leftOperand, rightOperand); 121 } 122 123 @Override 124 public boolean isCompilable() { 125 if (!getLeftOperand().isCompilable()) { 126 return false; 127 } 128 if (this.children.length > 1) { 129 if (!getRightOperand().isCompilable()) { 130 return false; 131 } 132 } 133 return (this.exitTypeDescriptor != null); 134 } 135 136 @Override 137 public void generateCode(MethodVisitor mv, CodeFlow cf) { 138 getLeftOperand().generateCode(mv, cf); 139 String leftDesc = getLeftOperand().exitTypeDescriptor; 140 String exitDesc = this.exitTypeDescriptor; 141 Assert.state(exitDesc != null, "No exit type descriptor"); 142 char targetDesc = exitDesc.charAt(0); 143 CodeFlow.insertNumericUnboxOrPrimitiveTypeCoercion(mv, leftDesc, targetDesc); 144 if (this.children.length > 1) { 145 cf.enterCompilationScope(); 146 getRightOperand().generateCode(mv, cf); 147 String rightDesc = getRightOperand().exitTypeDescriptor; 148 cf.exitCompilationScope(); 149 CodeFlow.insertNumericUnboxOrPrimitiveTypeCoercion(mv, rightDesc, targetDesc); 150 switch (targetDesc) { 151 case 'I': 152 mv.visitInsn(IMUL); 153 break; 154 case 'J': 155 mv.visitInsn(LMUL); 156 break; 157 case 'F': 158 mv.visitInsn(FMUL); 159 break; 160 case 'D': 161 mv.visitInsn(DMUL); 162 break; 163 default: 164 throw new IllegalStateException( 165 "Unrecognized exit type descriptor: '" + this.exitTypeDescriptor + "'"); 166 } 167 } 168 cf.pushDescriptor(this.exitTypeDescriptor); 169 } 170 171}