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.classfile;
019
020import java.io.DataInput;
021import java.io.DataOutputStream;
022import java.io.IOException;
023
024import org.apache.bcel.Const;
025
026/**
027 * This class is derived from the abstract  {@link Constant}
028 * and represents a reference to a Double object.
029 *
030 * @see     Constant
031 */
032public final class ConstantDouble extends Constant implements ConstantObject {
033
034    private double bytes;
035
036
037    /**
038     * @param bytes Data
039     */
040    public ConstantDouble(final double bytes) {
041        super(Const.CONSTANT_Double);
042        this.bytes = bytes;
043    }
044
045
046    /**
047     * Initialize from another object.
048     */
049    public ConstantDouble(final ConstantDouble c) {
050        this(c.getBytes());
051    }
052
053
054    /**
055     * Initialize instance from file data.
056     *
057     * @param file Input stream
058     * @throws IOException
059     */
060    ConstantDouble(final DataInput file) throws IOException {
061        this(file.readDouble());
062    }
063
064
065    /**
066     * Called by objects that are traversing the nodes of the tree implicitely
067     * defined by the contents of a Java class. I.e., the hierarchy of methods,
068     * fields, attributes, etc. spawns a tree of objects.
069     *
070     * @param v Visitor object
071     */
072    @Override
073    public void accept( final Visitor v ) {
074        v.visitConstantDouble(this);
075    }
076
077
078    /**
079     * Dump constant double to file stream in binary format.
080     *
081     * @param file Output file stream
082     * @throws IOException
083     */
084    @Override
085    public void dump( final DataOutputStream file ) throws IOException {
086        file.writeByte(super.getTag());
087        file.writeDouble(bytes);
088    }
089
090
091    /**
092     * @return data, i.e., 8 bytes.
093     */
094    public double getBytes() {
095        return bytes;
096    }
097
098
099    /**
100     * @param bytes the raw bytes that represent the double value
101     */
102    public void setBytes( final double bytes ) {
103        this.bytes = bytes;
104    }
105
106
107    /**
108     * @return String representation.
109     */
110    @Override
111    public String toString() {
112        return super.toString() + "(bytes = " + bytes + ")";
113    }
114
115
116    /** @return Double object
117     */
118    @Override
119    public Object getConstantValue( final ConstantPool cp ) {
120        return new Double(bytes);
121    }
122}