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.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 invoke dynamic.
027 *
028 * @see Constant
029 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.4.10"> The
030 *      CONSTANT_InvokeDynamic_info Structure in The Java Virtual Machine Specification</a>
031 * @since 6.0
032 */
033public final class ConstantInvokeDynamic extends ConstantCP {
034
035    /**
036     * Initialize from another object.
037     */
038    public ConstantInvokeDynamic(final ConstantInvokeDynamic c) {
039        this(c.getBootstrapMethodAttrIndex(), c.getNameAndTypeIndex());
040    }
041
042    /**
043     * Initialize instance from file data.
044     *
045     * @param file Input stream
046     * @throws IOException if an I/O error occurs.
047     */
048    ConstantInvokeDynamic(final DataInput file) throws IOException {
049        this(file.readShort(), file.readShort());
050    }
051
052    public ConstantInvokeDynamic(final int bootstrapMethodAttrIndex, final int nameAndTypeIndex) {
053        super(Const.CONSTANT_InvokeDynamic, bootstrapMethodAttrIndex, nameAndTypeIndex);
054    }
055
056    /**
057     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
058     * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
059     *
060     * @param v Visitor object
061     */
062    @Override
063    public void accept(final Visitor v) {
064        v.visitConstantInvokeDynamic(this);
065    }
066
067    /**
068     * @return Reference (index) to bootstrap method this constant refers to.
069     *
070     *         Note that this method is a functional duplicate of getClassIndex for use by ConstantInvokeDynamic.
071     * @since 6.0
072     */
073    public int getBootstrapMethodAttrIndex() {
074        return super.getClassIndex(); // AKA bootstrap_method_attr_index
075    }
076
077    /**
078     * @return String representation
079     */
080    @Override
081    public String toString() {
082        return super.toString().replace("class_index", "bootstrap_method_attr_index");
083    }
084}