    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}