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.classfile;
018
019import java.io.DataInput;
020import java.io.DataOutputStream;
021import java.io.IOException;
022
023import org.apache.bcel.Const;
024
025/**
026 * This class is derived from the abstract {@link Constant} and represents a reference to a method handle.
027 *
028 * @see Constant
029 * @since 6.0
030 */
031public final class ConstantMethodHandle extends Constant {
032
033    private int referenceKind;
034    private int referenceIndex;
035
036    /**
037     * Initialize from another object.
038     *
039     * @param c Source to copy.
040     */
041    public ConstantMethodHandle(final ConstantMethodHandle c) {
042        this(c.getReferenceKind(), c.getReferenceIndex());
043    }
044
045    /**
046     * Initialize instance from file data.
047     *
048     * @param file Input stream
049     * @throws IOException if an I/O error occurs.
050     */
051    ConstantMethodHandle(final DataInput file) throws IOException {
052        this(file.readUnsignedByte(), file.readUnsignedShort());
053    }
054
055    public ConstantMethodHandle(final int referenceKind, final int referenceIndex) {
056        super(Const.CONSTANT_MethodHandle);
057        this.referenceKind = referenceKind;
058        this.referenceIndex = referenceIndex;
059    }
060
061    /**
062     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
063     * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
064     *
065     * @param v Visitor object
066     */
067    @Override
068    public void accept(final Visitor v) {
069        v.visitConstantMethodHandle(this);
070    }
071
072    /**
073     * Dump method kind and index to file stream in binary format.
074     *
075     * @param file Output file stream
076     * @throws IOException if an I/O error occurs.
077     */
078    @Override
079    public void dump(final DataOutputStream file) throws IOException {
080        file.writeByte(super.getTag());
081        file.writeByte(referenceKind);
082        file.writeShort(referenceIndex);
083    }
084
085    public int getReferenceIndex() {
086        return referenceIndex;
087    }
088
089    public int getReferenceKind() {
090        return referenceKind;
091    }
092
093    public void setReferenceIndex(final int referenceIndex) {
094        this.referenceIndex = referenceIndex;
095    }
096
097    public void setReferenceKind(final int referenceKind) {
098        this.referenceKind = referenceKind;
099    }
100
101    /**
102     * @return String representation
103     */
104    @Override
105    public String toString() {
106        return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")";
107    }
108}