    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 */
    017package org.apache.bcel.generic;
    018
    019/**
    020 * DCONST - Push 0.0 or 1.0, other values cause an exception
    021 *
    022 * <PRE>
    023 * Stack: ... -&gt; ...,
    024 * </PRE>
    025 */
    026public class DCONST extends Instruction implements ConstantPushInstruction {
    027
    028    private final double value;
    029
    030    /**
    031     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
    032     */
    033    DCONST() {
    034        this(0);
    035    }
    036
    037    public DCONST(final double f) {
    038        super(org.apache.bcel.Const.DCONST_0, (short) 1);
    039        if (f == 0.0) {
    040            super.setOpcode(org.apache.bcel.Const.DCONST_0);
    041        } else if (f == 1.0) {
    042            super.setOpcode(org.apache.bcel.Const.DCONST_1);
    043        } else {
    044            throw new ClassGenException("DCONST can be used only for 0.0 and 1.0: " + f);
    045        }
    046        value = f;
    047    }
    048
    049    /**
    050     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
    051     * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
    052     *
    053     * @param v Visitor object
    054     */
    055    @Override
    056    public void accept(final Visitor v) {
    057        v.visitPushInstruction(this);
    058        v.visitStackProducer(this);
    059        v.visitTypedInstruction(this);
    060        v.visitConstantPushInstruction(this);
    061        v.visitDCONST(this);
    062    }
    063
    064    /**
    065     * @return Type.DOUBLE
    066     */
    067    @Override
    068    public Type getType(final ConstantPoolGen cp) {
    069        return Type.DOUBLE;
    070    }
    071
    072    @Override
    073    public Number getValue() {
    074        return Double.valueOf(value);
    075    }
    076}