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}
028 * 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 reference_kind;
036    private int reference_index;
037
038
039    /**
040     * Initialize from another object.
041     */
042    public ConstantMethodHandle(final ConstantMethodHandle c) {
043        this(c.getReferenceKind(), c.getReferenceIndex());
044    }
045
046
047    /**
048     * Initialize instance from file data.
049     *
050     * @param file Input stream
051     * @throws IOException
052     */
053    ConstantMethodHandle(final DataInput file) throws IOException {
054        this(file.readUnsignedByte(), file.readUnsignedShort());
055    }
056
057
058    public ConstantMethodHandle(final int reference_kind, final int reference_index) {
059        super(Const.CONSTANT_MethodHandle);
060        this.reference_kind = reference_kind;
061        this.reference_index = reference_index;
062    }
063
064
065    /**
066     * Called by objects that are traversing the nodes of the tree implicitly
067     * defined by the contents of a Java class. I.e., the hierarchy of methods,
068     * fields, attributes, etc. spawns a tree of objects.
069     *
070     * @param v Visitor object
071     */
072    @Override
073    public void accept( final Visitor v ) {
074        v.visitConstantMethodHandle(this);
075    }
076
077
078    /**
079     * Dump method kind and index to file stream in binary format.
080     *
081     * @param file Output file stream
082     * @throws IOException
083     */
084    @Override
085    public void dump( final DataOutputStream file ) throws IOException {
086        file.writeByte(super.getTag());
087        file.writeByte(reference_kind);
088        file.writeShort(reference_index);
089    }
090
091
092    public int getReferenceKind() {
093        return reference_kind;
094    }
095
096
097    public void setReferenceKind(final int reference_kind) {
098        this.reference_kind = reference_kind;
099    }
100
101
102    public int getReferenceIndex() {
103        return reference_index;
104    }
105
106
107    public void setReferenceIndex(final int reference_index) {
108        this.reference_index = reference_index;
109    }
110
111
112    /**
113     * @return String representation
114     */
115    @Override
116    public String toString() {
117        return super.toString() + "(reference_kind = " + reference_kind +
118                ", reference_index = " + reference_index + ")";
119    }
120}