    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.DataOutputStream;
    021import java.io.IOException;
    022import java.util.Arrays;
    023import java.util.Iterator;
    024import java.util.stream.Stream;
    025
    026import org.apache.bcel.Const;
    027
    028/**
    029 * This class is derived from <em>Attribute</em> and denotes that this class is an Inner class of another. to the source
    030 * file of this class. It is instantiated from the <em>Attribute.readAttribute()</em> method.
    031 *
    032 * @see Attribute
    033 */
    034public final class InnerClasses extends Attribute implements Iterable<InnerClass> {
    035
    036    /**
    037     * Empty array.
    038     */
    039    private static final InnerClass[] EMPTY_INNER_CLASSE_ARRAY = {};
    040
    041    private InnerClass[] innerClasses;
    042
    043    /**
    044     * Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a
    045     * physical copy.
    046     */
    047    public InnerClasses(final InnerClasses c) {
    048        this(c.getNameIndex(), c.getLength(), c.getInnerClasses(), c.getConstantPool());
    049    }
    050
    051    /**
    052     * Construct object from input stream.
    053     *
    054     * @param nameIndex Index in constant pool to CONSTANT_Utf8
    055     * @param length Content length in bytes
    056     * @param input Input stream
    057     * @param constantPool Array of constants
    058     * @throws IOException if an I/O error occurs.
    059     */
    060    InnerClasses(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
    061        this(nameIndex, length, (InnerClass[]) null, constantPool);
    062        final int classCount = input.readUnsignedShort();
    063        innerClasses = new InnerClass[classCount];
    064        for (int i = 0; i < classCount; i++) {
    065            innerClasses[i] = new InnerClass(input);
    066        }
    067    }
    068
    069    /**
    070     * @param nameIndex Index in constant pool to CONSTANT_Utf8
    071     * @param length Content length in bytes
    072     * @param innerClasses array of inner classes attributes
    073     * @param constantPool Array of constants
    074     */
    075    public InnerClasses(final int nameIndex, final int length, final InnerClass[] innerClasses, final ConstantPool constantPool) {
    076        super(Const.ATTR_INNER_CLASSES, nameIndex, length, constantPool);
    077        this.innerClasses = innerClasses != null ? innerClasses : EMPTY_INNER_CLASSE_ARRAY;
    078    }
    079
    080    /**
    081     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
    082     * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
    083     *
    084     * @param v Visitor object
    085     */
    086    @Override
    087    public void accept(final Visitor v) {
    088        v.visitInnerClasses(this);
    089    }
    090
    091    /**
    092     * @return deep copy of this attribute
    093     */
    094    @Override
    095    public Attribute copy(final ConstantPool constantPool) {
    096        // TODO this could be recoded to use a lower level constructor after creating a copy of the inner classes
    097        final InnerClasses c = (InnerClasses) clone();
    098        c.innerClasses = new InnerClass[innerClasses.length];
    099        Arrays.setAll(c.innerClasses, i -> innerClasses[i].copy());
    100        c.setConstantPool(constantPool);
    101        return c;
    102    }
    103
    104    /**
    105     * Dump source file attribute to file stream in binary format.
    106     *
    107     * @param file Output file stream
    108     * @throws IOException if an I/O error occurs.
    109     */
    110    @Override
    111    public void dump(final DataOutputStream file) throws IOException {
    112        super.dump(file);
    113        file.writeShort(innerClasses.length);
    114        for (final InnerClass innerClass : innerClasses) {
    115            innerClass.dump(file);
    116        }
    117    }
    118
    119    /**
    120     * @return array of inner class "records"
    121     */
    122    public InnerClass[] getInnerClasses() {
    123        return innerClasses;
    124    }
    125
    126    @Override
    127    public Iterator<InnerClass> iterator() {
    128        return Stream.of(innerClasses).iterator();
    129    }
    130
    131    /**
    132     * @param innerClasses the array of inner classes
    133     */
    134    public void setInnerClasses(final InnerClass[] innerClasses) {
    135        this.innerClasses = innerClasses != null ? innerClasses : EMPTY_INNER_CLASSE_ARRAY;
    136    }
    137
    138    /**
    139     * @return String representation.
    140     */
    141    @Override
    142    public String toString() {
    143        final StringBuilder buf = new StringBuilder();
    144        buf.append("InnerClasses(");
    145        buf.append(innerClasses.length);
    146        buf.append("):\n");
    147        for (final InnerClass innerClass : innerClasses) {
    148            buf.append(innerClass.toString(super.getConstantPool())).append("\n");
    149        }
    150        return buf.substring(0, buf.length() - 1); // remove the last newline
    151    }
    152}