001/*
002 * Copyright 2002-2016 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 org.springframework.asm.MethodVisitor;
020import org.springframework.expression.spel.CodeFlow;
021import org.springframework.expression.spel.support.BooleanTypedValue;
022
023/**
024 * Represents the literal values {@code TRUE} and {@code FALSE}.
025 *
026 * @author Andy Clement
027 * @since 3.0
028 */
029public class BooleanLiteral extends Literal {
030
031        private final BooleanTypedValue value;
032
033
034        public BooleanLiteral(String payload, int pos, boolean value) {
035                super(payload, pos);
036                this.value = BooleanTypedValue.forValue(value);
037                this.exitTypeDescriptor = "Z";
038        }
039
040
041        @Override
042        public BooleanTypedValue getLiteralValue() {
043                return this.value;
044        }
045        
046        @Override
047        public boolean isCompilable() {
048                return true;
049        }
050        
051        @Override
052        public void generateCode(MethodVisitor mv, CodeFlow cf) {
053                if (this.value == BooleanTypedValue.TRUE) {
054                        mv.visitLdcInsn(1);             
055                }
056                else {
057                        mv.visitLdcInsn(0);
058                }
059                cf.pushDescriptor(this.exitTypeDescriptor);
060        }
061
062}