    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    /**
    058     * Constructs a ConstantMethodHandle.
    059     *
    060     * @param referenceKind Kind of method reference.
    061     * @param referenceIndex Index to the method reference.
    062     */
    063    public ConstantMethodHandle(final int referenceKind, final int referenceIndex) {
    064        super(Const.CONSTANT_MethodHandle);
    065        this.referenceKind = referenceKind;
    066        this.referenceIndex = referenceIndex;
    067    }
    068
    069    /**
    070     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
    071     * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
    072     *
    073     * @param v Visitor object.
    074     */
    075    @Override
    076    public void accept(final Visitor v) {
    077        v.visitConstantMethodHandle(this);
    078    }
    079
    080    /**
    081     * Dumps method kind and index to file stream in binary format.
    082     *
    083     * @param file Output file stream.
    084     * @throws IOException if an I/O error occurs.
    085     */
    086    @Override
    087    public void dump(final DataOutputStream file) throws IOException {
    088        file.writeByte(super.getTag());
    089        file.writeByte(referenceKind);
    090        file.writeShort(referenceIndex);
    091    }
    092
    093    /**
    094     * Gets the reference index.
    095     *
    096     * @return the reference index.
    097     */
    098    public int getReferenceIndex() {
    099        return referenceIndex;
    100    }
    101
    102    /**
    103     * Gets the reference kind.
    104     *
    105     * @return the reference kind.
    106     */
    107    public int getReferenceKind() {
    108        return referenceKind;
    109    }
    110
    111    /**
    112     * Sets the reference index.
    113     *
    114     * @param referenceIndex the reference index.
    115     */
    116    public void setReferenceIndex(final int referenceIndex) {
    117        this.referenceIndex = referenceIndex;
    118    }
    119
    120    /**
    121     * Sets the reference kind.
    122     *
    123     * @param referenceKind the reference kind.
    124     */
    125    public void setReferenceKind(final int referenceKind) {
    126        this.referenceKind = referenceKind;
    127    }
    128
    129    /**
    130     * @return String representation.
    131     */
    132    @Override
    133    public String toString() {
    134        return super.toString() + "(referenceKind = " + referenceKind + ", referenceIndex = " + referenceIndex + ")";
    135    }
    136}