/*
* Copyright 2002-2014 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.core.convert.TypeDescriptor;
import org.springframework.expression.EvaluationException;
import org.springframework.expression.Operation;
import org.springframework.expression.TypeConverter;
import org.springframework.expression.TypedValue;
import org.springframework.expression.spel.CodeFlow;
import org.springframework.expression.spel.ExpressionState;
import org.springframework.util.Assert;
import org.springframework.util.NumberUtils;
/**
* The plus operator will:
* <ul>
* <li>add numbers
* <li>concatenate strings
* </ul>
*
* <p>It can be used as a unary operator for numbers.
* The standard promotions are performed when the operand types vary (double+int=double).
* For other options it defers to the registered overloader.
*
* @author Andy Clement
* @author Juergen Hoeller
* @author Ivo Smid
* @author Giovanni Dall'Oglio Risso
* @since 3.0
*/
public class OpPlus extends Operator {
public OpPlus(int pos, SpelNodeImpl... operands) {
super("+", pos, operands);
Assert.notEmpty(operands);
}
@Override
public TypedValue getValueInternal(ExpressionState state) throws EvaluationException {
SpelNodeImpl leftOp = getLeftOperand();
SpelNodeImpl rightOp = getRightOperand();
if (rightOp == null) { // if only one operand, then this is unary plus
Object operandOne = leftOp.getValueInternal(state).getValue();
if (operandOne instanceof Number) {
if (operandOne instanceof Double) {
this.exitTypeDescriptor = "D";
}
else if (operandOne instanceof Float) {
this.exitTypeDescriptor = "F";
}
else if (operandOne instanceof Long) {
this.exitTypeDescriptor = "J";
}
else if (operandOne instanceof Integer) {
this.exitTypeDescriptor = "I";
}
return new TypedValue(operandOne);
}
return state.operate(Operation.ADD, operandOne, null);
}
TypedValue operandOneValue = leftOp.getValueInternal(state);
Object leftOperand = operandOneValue.getValue();
TypedValue operandTwoValue = rightOp.getValueInternal(state);
Object rightOperand = operandTwoValue.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.add(rightBigDecimal));
}
else if (leftNumber instanceof Double || rightNumber instanceof Double) {
if (leftNumber.getClass() == rightNumber.getClass()) {
this.exitTypeDescriptor = "D";
}
return new TypedValue(leftNumber.doubleValue() + rightNumber.doubleValue());
}
else if (leftNumber instanceof Float || rightNumber instanceof Float) {
if (leftNumber.getClass() == rightNumber.getClass()) {
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.add(rightBigInteger));
}
else if (leftNumber instanceof Long || rightNumber instanceof Long) {
if (leftNumber.getClass() == rightNumber.getClass()) {
this.exitTypeDescriptor = "J";
}
return new TypedValue(leftNumber.longValue() + rightNumber.longValue());
}
else if (CodeFlow.isIntegerForNumericOp(leftNumber) || CodeFlow.isIntegerForNumericOp(rightNumber)) {
if (leftNumber instanceof Integer && rightNumber instanceof Integer) {
this.exitTypeDescriptor = "I";
}
return new TypedValue(leftNumber.intValue() + rightNumber.intValue());
}
else {
// Unknown Number subtypes -> best guess is double addition
return new TypedValue(leftNumber.doubleValue() + rightNumber.doubleValue());
}
}
if (leftOperand instanceof String && rightOperand instanceof String) {
this.exitTypeDescriptor = "Ljava/lang/String";
return new TypedValue((String) leftOperand + rightOperand);
}
if (leftOperand instanceof String) {
return new TypedValue(
leftOperand + (rightOperand == null ? "null" : convertTypedValueToString(operandTwoValue, state)));
}
if (rightOperand instanceof String) {
return new TypedValue(
(leftOperand == null ? "null" : convertTypedValueToString(operandOneValue, state)) + rightOperand);
}
return state.operate(Operation.ADD, leftOperand, rightOperand);
}
@Override
public String toStringAST() {
if (this.children.length < 2) { // unary plus
return "+" + getLeftOperand().toStringAST();
}
return super.toStringAST();
}
@Override
public SpelNodeImpl getRightOperand() {
if (this.children.length < 2) {
return null;
}
return this.children[1];
}
/**
* Convert operand value to string using registered converter or using
* {@code toString} method.
* @param value typed value to be converted
* @param state expression state
* @return {@code TypedValue} instance converted to {@code String}
*/
private static String convertTypedValueToString(TypedValue value, ExpressionState state) {
TypeConverter typeConverter = state.getEvaluationContext().getTypeConverter();
TypeDescriptor typeDescriptor = TypeDescriptor.valueOf(String.class);
if (typeConverter.canConvert(value.getTypeDescriptor(), typeDescriptor)) {
return String.valueOf(typeConverter.convertValue(value.getValue(),
value.getTypeDescriptor(), typeDescriptor));
}
return String.valueOf(value.getValue());
}
@Override
public boolean isCompilable() {
if (!getLeftOperand().isCompilable()) {
return false;
}
if (this.children.length > 1) {
if (!getRightOperand().isCompilable()) {
return false;
}
}
return (this.exitTypeDescriptor != null);
}
/**
* Walk through a possible tree of nodes that combine strings and append
* them all to the same (on stack) StringBuilder.
*/
private void walk(MethodVisitor mv, CodeFlow cf, SpelNodeImpl operand) {
if (operand instanceof OpPlus) {
OpPlus plus = (OpPlus)operand;
walk(mv,cf,plus.getLeftOperand());
walk(mv,cf,plus.getRightOperand());
}
else {
cf.enterCompilationScope();
operand.generateCode(mv,cf);
cf.exitCompilationScope();
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "append", "(Ljava/lang/String;)Ljava/lang/StringBuilder;", false);
}
}
@Override
public void generateCode(MethodVisitor mv, CodeFlow cf) {
if (this.exitTypeDescriptor == "Ljava/lang/String") {
mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
mv.visitInsn(DUP);
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "()V", false);
walk(mv,cf,getLeftOperand());
walk(mv,cf,getRightOperand());
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;", false);
}
else {
getLeftOperand().generateCode(mv, cf);
String leftDesc = getLeftOperand().exitTypeDescriptor;
if (!CodeFlow.isPrimitive(leftDesc)) {
CodeFlow.insertUnboxInsns(mv, this.exitTypeDescriptor.charAt(0), leftDesc);
}
if (this.children.length > 1) {
cf.enterCompilationScope();
getRightOperand().generateCode(mv, cf);
String rightDesc = getRightOperand().exitTypeDescriptor;
cf.exitCompilationScope();
if (!CodeFlow.isPrimitive(rightDesc)) {
CodeFlow.insertUnboxInsns(mv, this.exitTypeDescriptor.charAt(0), rightDesc);
}
switch (this.exitTypeDescriptor.charAt(0)) {
case 'I':
mv.visitInsn(IADD);
break;
case 'J':
mv.visitInsn(LADD);
break;
case 'F':
mv.visitInsn(FADD);
break;
case 'D':
mv.visitInsn(DADD);
break;
default:
throw new IllegalStateException(
"Unrecognized exit type descriptor: '" + this.exitTypeDescriptor + "'");
}
}
}
cf.pushDescriptor(this.exitTypeDescriptor);
}
}