001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.bcel.classfile;
020
021import java.io.DataInput;
022import java.io.DataOutputStream;
023import java.io.IOException;
024
025import org.apache.bcel.Const;
026
027/**
028 * This class is derived from the abstract {@link Constant} and represents a reference to a method handle.
029 *
030 * @see Constant
031 * @since 6.0
032 */
033public final class ConstantMethodHandle extends Constant {
034
035    private int referenceKind;
036    private int referenceIndex;
037
038    /**
039     * Initialize from another object.
040     *
041     * @param c Source to copy.
042     */
043    public ConstantMethodHandle(final ConstantMethodHandle c) {
044        this(c.getReferenceKind(), c.getReferenceIndex());
045    }
046
047    /**
048     * Initialize instance from file data.
049     *
050     * @param file Input stream
051     * @throws IOException if an I/O error occurs.
052     */
053    ConstantMethodHandle(final DataInput file) throws IOException {
054        this(file.readUnsignedByte(), file.readUnsignedShort());
055    }
056
057    public ConstantMethodHandle(final int referenceKind, final int referenceIndex) {
058        super(Const.CONSTANT_MethodHandle);
059        this.referenceKind = referenceKind;
060        this.referenceIndex = referenceIndex;
061    }
062
063    /**
064     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
065     * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
066     *
067     * @param v Visitor object
068     */
069    @Override
070    public void accept(final Visitor v) {
071        v.visitConstantMethodHandle(this);
072    }
073
074    /**
075     * Dump method kind and index to file stream in binary format.
076     *
077     * @param file Output file stream
078     * @throws IOException if an I/O error occurs.
079     */
080    @Override
081    public void dump(final DataOutputStream file) throws IOException {
082        file.writeByte(super.getTag());
083        file.writeByte(referenceKind);
084        file.writeShort(referenceIndex);
085    }
086
087    public int getReferenceIndex() {
088        return referenceIndex;
089    }
090
091    public int getReferenceKind() {
092        return referenceKind;
093    }
094
095    public void setReferenceIndex(final int referenceIndex) {
096        this.referenceIndex = referenceIndex;
097    }
098
099    public void setReferenceKind(final int referenceKind) {
100        this.referenceKind = referenceKind;
101    }
102
103    /**
104     * @return String representation
105     */
106    @Override
107    public String toString() {
108        return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")";
109    }
110}