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} and represents a reference to a method handle.
028 *
029 * @see Constant
030 * @since 6.0
031 */
032public final class ConstantMethodHandle extends Constant {
033
034    private int referenceKind;
035    private int referenceIndex;
036
037    /**
038     * Initialize from another object.
039     */
040    public ConstantMethodHandle(final ConstantMethodHandle c) {
041        this(c.getReferenceKind(), c.getReferenceIndex());
042    }
043
044    /**
045     * Initialize instance from file data.
046     *
047     * @param file Input stream
048     * @throws IOException if an I/O error occurs.
049     */
050    ConstantMethodHandle(final DataInput file) throws IOException {
051        this(file.readUnsignedByte(), file.readUnsignedShort());
052    }
053
054    public ConstantMethodHandle(final int reference_kind, final int reference_index) {
055        super(Const.CONSTANT_MethodHandle);
056        this.referenceKind = reference_kind;
057        this.referenceIndex = reference_index;
058    }
059
060    /**
061     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
062     * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
063     *
064     * @param v Visitor object
065     */
066    @Override
067    public void accept(final Visitor v) {
068        v.visitConstantMethodHandle(this);
069    }
070
071    /**
072     * Dump method kind and index to file stream in binary format.
073     *
074     * @param file Output file stream
075     * @throws IOException if an I/O error occurs.
076     */
077    @Override
078    public void dump(final DataOutputStream file) throws IOException {
079        file.writeByte(super.getTag());
080        file.writeByte(referenceKind);
081        file.writeShort(referenceIndex);
082    }
083
084    public int getReferenceIndex() {
085        return referenceIndex;
086    }
087
088    public int getReferenceKind() {
089        return referenceKind;
090    }
091
092    public void setReferenceIndex(final int reference_index) {
093        this.referenceIndex = reference_index;
094    }
095
096    public void setReferenceKind(final int reference_kind) {
097        this.referenceKind = reference_kind;
098    }
099
100    /**
101     * @return String representation
102     */
103    @Override
104    public String toString() {
105        return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")";
106    }
107}