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