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.IOException;
021
022import org.apache.bcel.Const;
023
024/**
025 * This class is derived from the abstract {@link Constant} and represents a reference to a invoke dynamic.
026 *
027 * @see Constant
028 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.4.10"> The
029 *      CONSTANT_InvokeDynamic_info Structure in The Java Virtual Machine Specification</a>
030 * @since 6.0
031 */
032public final class ConstantInvokeDynamic extends ConstantCP {
033
034    /**
035     * Initialize from another object.
036     */
037    public ConstantInvokeDynamic(final ConstantInvokeDynamic c) {
038        this(c.getBootstrapMethodAttrIndex(), c.getNameAndTypeIndex());
039    }
040
041    /**
042     * Initialize instance from file data.
043     *
044     * @param file Input stream
045     * @throws IOException if an I/O error occurs.
046     */
047    ConstantInvokeDynamic(final DataInput file) throws IOException {
048        this(file.readShort(), file.readShort());
049    }
050
051    public ConstantInvokeDynamic(final int bootstrapMethodAttrIndex, final int nameAndTypeIndex) {
052        super(Const.CONSTANT_InvokeDynamic, bootstrapMethodAttrIndex, nameAndTypeIndex);
053    }
054
055    /**
056     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. I.e.,
057     * the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
058     *
059     * @param v Visitor object
060     */
061    @Override
062    public void accept(final Visitor v) {
063        v.visitConstantInvokeDynamic(this);
064    }
065
066    /**
067     * @return Reference (index) to bootstrap method this constant refers to.
068     *
069     *         Note that this method is a functional duplicate of getClassIndex for use by ConstantInvokeDynamic.
070     * @since 6.0
071     */
072    public int getBootstrapMethodAttrIndex() {
073        return super.getClassIndex(); // AKA bootstrap_method_attr_index
074    }
075
076    /**
077     * @return String representation
078     */
079    @Override
080    public String toString() {
081        return super.toString().replace("class_index", "bootstrap_method_attr_index");
082    }
083}