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; 023import java.util.Arrays; 024import java.util.Iterator; 025import java.util.stream.Stream; 026 027import org.apache.bcel.Const; 028 029/** 030 * This class is derived from <em>Attribute</em> and denotes that this class is an Inner class of another. to the source 031 * file of this class. It is instantiated from the <em>Attribute.readAttribute()</em> method. 032 * 033 * @see Attribute 034 */ 035public final class InnerClasses extends Attribute implements Iterable<InnerClass> { 036 037 /** 038 * Empty array. 039 */ 040 private static final InnerClass[] EMPTY_INNER_CLASSE_ARRAY = {}; 041 042 private InnerClass[] innerClasses; 043 044 /** 045 * Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a 046 * physical copy. 047 */ 048 public InnerClasses(final InnerClasses c) { 049 this(c.getNameIndex(), c.getLength(), c.getInnerClasses(), c.getConstantPool()); 050 } 051 052 /** 053 * Construct object from input stream. 054 * 055 * @param name_index Index in constant pool to CONSTANT_Utf8 056 * @param length Content length in bytes 057 * @param input Input stream 058 * @param constant_pool Array of constants 059 * @throws IOException if an I/O error occurs. 060 */ 061 InnerClasses(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException { 062 this(name_index, length, (InnerClass[]) null, constant_pool); 063 final int number_of_classes = input.readUnsignedShort(); 064 innerClasses = new InnerClass[number_of_classes]; 065 for (int i = 0; i < number_of_classes; i++) { 066 innerClasses[i] = new InnerClass(input); 067 } 068 } 069 070 /** 071 * @param name_index Index in constant pool to CONSTANT_Utf8 072 * @param length Content length in bytes 073 * @param innerClasses array of inner classes attributes 074 * @param constant_pool Array of constants 075 */ 076 public InnerClasses(final int name_index, final int length, final InnerClass[] innerClasses, final ConstantPool constant_pool) { 077 super(Const.ATTR_INNER_CLASSES, name_index, length, constant_pool); 078 this.innerClasses = innerClasses != null ? innerClasses : EMPTY_INNER_CLASSE_ARRAY; 079 } 080 081 /** 082 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. 083 * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects. 084 * 085 * @param v Visitor object 086 */ 087 @Override 088 public void accept(final Visitor v) { 089 v.visitInnerClasses(this); 090 } 091 092 /** 093 * @return deep copy of this attribute 094 */ 095 @Override 096 public Attribute copy(final ConstantPool constantPool) { 097 // TODO this could be recoded to use a lower level constructor after creating a copy of the inner classes 098 final InnerClasses c = (InnerClasses) clone(); 099 c.innerClasses = new InnerClass[innerClasses.length]; 100 Arrays.setAll(c.innerClasses, i -> innerClasses[i].copy()); 101 c.setConstantPool(constantPool); 102 return c; 103 } 104 105 /** 106 * Dump source file attribute to file stream in binary format. 107 * 108 * @param file Output file stream 109 * @throws IOException if an I/O error occurs. 110 */ 111 @Override 112 public void dump(final DataOutputStream file) throws IOException { 113 super.dump(file); 114 file.writeShort(innerClasses.length); 115 for (final InnerClass inner_class : innerClasses) { 116 inner_class.dump(file); 117 } 118 } 119 120 /** 121 * @return array of inner class "records" 122 */ 123 public InnerClass[] getInnerClasses() { 124 return innerClasses; 125 } 126 127 @Override 128 public Iterator<InnerClass> iterator() { 129 return Stream.of(innerClasses).iterator(); 130 } 131 132 /** 133 * @param innerClasses the array of inner classes 134 */ 135 public void setInnerClasses(final InnerClass[] innerClasses) { 136 this.innerClasses = innerClasses != null ? innerClasses : EMPTY_INNER_CLASSE_ARRAY; 137 } 138 139 /** 140 * @return String representation. 141 */ 142 @Override 143 public String toString() { 144 final StringBuilder buf = new StringBuilder(); 145 buf.append("InnerClasses("); 146 buf.append(innerClasses.length); 147 buf.append("):\n"); 148 for (final InnerClass inner_class : innerClasses) { 149 buf.append(inner_class.toString(super.getConstantPool())).append("\n"); 150 } 151 return buf.substring(0, buf.length() - 1); // remove the last newline 152 } 153}