/*
 * Copyright 2002-2018 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.asm.Label;
import org.springframework.asm.MethodVisitor;
import org.springframework.expression.EvaluationException;
import org.springframework.expression.spel.CodeFlow;
import org.springframework.expression.spel.ExpressionState;
import org.springframework.expression.spel.SpelEvaluationException;
import org.springframework.expression.spel.SpelMessage;
import org.springframework.expression.spel.support.BooleanTypedValue;
import org.springframework.lang.Nullable;

Represents the boolean OR operation.
Author:Andy Clement, Mark Fisher, Oliver Becker
Since:3.0
/** * Represents the boolean OR operation. * * @author Andy Clement * @author Mark Fisher * @author Oliver Becker * @since 3.0 */
public class OpOr extends Operator { public OpOr(int pos, SpelNodeImpl... operands) { super("or", pos, operands); this.exitTypeDescriptor = "Z"; } @Override public BooleanTypedValue getValueInternal(ExpressionState state) throws EvaluationException { if (getBooleanValue(state, getLeftOperand())) { // no need to evaluate right operand return BooleanTypedValue.TRUE; } return BooleanTypedValue.forValue(getBooleanValue(state, getRightOperand())); } private boolean getBooleanValue(ExpressionState state, SpelNodeImpl operand) { try { Boolean value = operand.getValue(state, Boolean.class); assertValueNotNull(value); return value; } catch (SpelEvaluationException ee) { ee.setPosition(operand.getStartPosition()); throw ee; } } private void assertValueNotNull(@Nullable Boolean value) { if (value == null) { throw new SpelEvaluationException(SpelMessage.TYPE_CONVERSION_ERROR, "null", "boolean"); } } @Override public boolean isCompilable() { SpelNodeImpl left = getLeftOperand(); SpelNodeImpl right = getRightOperand(); return (left.isCompilable() && right.isCompilable() && CodeFlow.isBooleanCompatible(left.exitTypeDescriptor) && CodeFlow.isBooleanCompatible(right.exitTypeDescriptor)); } @Override public void generateCode(MethodVisitor mv, CodeFlow cf) { // pseudo: if (leftOperandValue) { result=true; } else { result=rightOperandValue; } Label elseTarget = new Label(); Label endOfIf = new Label(); cf.enterCompilationScope(); getLeftOperand().generateCode(mv, cf); cf.unboxBooleanIfNecessary(mv); cf.exitCompilationScope(); mv.visitJumpInsn(IFEQ, elseTarget); mv.visitLdcInsn(1); // TRUE mv.visitJumpInsn(GOTO,endOfIf); mv.visitLabel(elseTarget); cf.enterCompilationScope(); getRightOperand().generateCode(mv, cf); cf.unboxBooleanIfNecessary(mv); cf.exitCompilationScope(); mv.visitLabel(endOfIf); cf.pushDescriptor(this.exitTypeDescriptor); } }