    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 *
    017 */
    018package org.apache.bcel.generic;
    019
    020/**
    021 * DCONST - Push 0.0 or 1.0, other values cause an exception
    022 *
    023 * <PRE>Stack: ... -&gt; ..., </PRE>
    024 *
    025 */
    026public class DCONST extends Instruction implements ConstantPushInstruction {
    027
    028    private double value;
    029
    030
    031    /**
    032     * Empty constructor needed for Instruction.readInstruction.
    033     * Not to be used otherwise.
    034     */
    035    DCONST() {
    036    }
    037
    038
    039    public DCONST(final double f) {
    040        super(org.apache.bcel.Const.DCONST_0, (short) 1);
    041        if (f == 0.0) {
    042            super.setOpcode(org.apache.bcel.Const.DCONST_0);
    043        } else if (f == 1.0) {
    044            super.setOpcode(org.apache.bcel.Const.DCONST_1);
    045        } else {
    046            throw new ClassGenException("DCONST can be used only for 0.0 and 1.0: " + f);
    047        }
    048        value = f;
    049    }
    050
    051
    052    @Override
    053    public Number getValue() {
    054        return new Double(value);
    055    }
    056
    057
    058    /** @return Type.DOUBLE
    059     */
    060    @Override
    061    public Type getType( final ConstantPoolGen cp ) {
    062        return Type.DOUBLE;
    063    }
    064
    065
    066    /**
    067     * Call corresponding visitor method(s). The order is:
    068     * Call visitor methods of implemented interfaces first, then
    069     * call methods according to the class hierarchy in descending order,
    070     * i.e., the most specific visitXXX() call comes last.
    071     *
    072     * @param v Visitor object
    073     */
    074    @Override
    075    public void accept( final Visitor v ) {
    076        v.visitPushInstruction(this);
    077        v.visitStackProducer(this);
    078        v.visitTypedInstruction(this);
    079        v.visitConstantPushInstruction(this);
    080        v.visitDCONST(this);
    081    }
    082}