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 dynamically computed 026 * constant. 027 * 028 * @see Constant 029 * @see <a href="https://bugs.openjdk.java.net/secure/attachment/74618/constant-dynamic.html"> Change request for JEP 030 * 309</a> 031 * @since 6.3 032 */ 033public final class ConstantDynamic extends ConstantCP { 034 035 /** 036 * Initialize from another object. 037 */ 038 public ConstantDynamic(final ConstantDynamic 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 ConstantDynamic(final DataInput file) throws IOException { 049 this(file.readShort(), file.readShort()); 050 } 051 052 public ConstantDynamic(final int bootstrapMethodAttrIndex, final int nameAndTypeIndex) { 053 super(Const.CONSTANT_Dynamic, 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.visitConstantDynamic(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}