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;
023
024import org.apache.bcel.Const;
025
026/**
027 * This class is derived from <em>Attribute</em> and denotes that this class
028 * is an Inner class of another.
029 * to the source file of this class.
030 * It is instantiated from the <em>Attribute.readAttribute()</em> method.
031 *
032 * @see     Attribute
033 */
034public final class InnerClasses extends Attribute {
035
036    private InnerClass[] innerClasses;
037
038
039    /**
040     * Initialize from another object. Note that both objects use the same
041     * references (shallow copy). Use clone() for a physical copy.
042     */
043    public InnerClasses(final InnerClasses c) {
044        this(c.getNameIndex(), c.getLength(), c.getInnerClasses(), c.getConstantPool());
045    }
046
047
048    /**
049     * @param name_index Index in constant pool to CONSTANT_Utf8
050     * @param length Content length in bytes
051     * @param innerClasses array of inner classes attributes
052     * @param constant_pool Array of constants
053     */
054    public InnerClasses(final int name_index, final int length, final InnerClass[] innerClasses,
055            final ConstantPool constant_pool) {
056        super(Const.ATTR_INNER_CLASSES, name_index, length, constant_pool);
057        this.innerClasses = innerClasses != null ? innerClasses : new InnerClass[0];
058    }
059
060
061    /**
062     * Construct object from input stream.
063     *
064     * @param name_index Index in constant pool to CONSTANT_Utf8
065     * @param length Content length in bytes
066     * @param input Input stream
067     * @param constant_pool Array of constants
068     * @throws IOException
069     */
070    InnerClasses(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)
071            throws IOException {
072        this(name_index, length, (InnerClass[]) null, constant_pool);
073        final int number_of_classes = input.readUnsignedShort();
074        innerClasses = new InnerClass[number_of_classes];
075        for (int i = 0; i < number_of_classes; i++) {
076            innerClasses[i] = new InnerClass(input);
077        }
078    }
079
080
081    /**
082     * Called by objects that are traversing the nodes of the tree implicitely
083     * defined by the contents of a Java class. I.e., the hierarchy of methods,
084     * fields, attributes, etc. spawns a tree of objects.
085     *
086     * @param v Visitor object
087     */
088    @Override
089    public void accept( final Visitor v ) {
090        v.visitInnerClasses(this);
091    }
092
093
094    /**
095     * Dump source file attribute to file stream in binary format.
096     *
097     * @param file Output file stream
098     * @throws IOException
099     */
100    @Override
101    public void dump( final DataOutputStream file ) throws IOException {
102        super.dump(file);
103        file.writeShort(innerClasses.length);
104        for (final InnerClass inner_class : innerClasses) {
105            inner_class.dump(file);
106        }
107    }
108
109
110    /**
111     * @return array of inner class "records"
112     */
113    public InnerClass[] getInnerClasses() {
114        return innerClasses;
115    }
116
117
118    /**
119     * @param innerClasses the array of inner classes
120     */
121    public void setInnerClasses( final InnerClass[] innerClasses ) {
122        this.innerClasses = innerClasses != null ? innerClasses : new InnerClass[0];
123    }
124
125
126    /**
127     * @return String representation.
128     */
129    @Override
130    public String toString() {
131        final StringBuilder buf = new StringBuilder();
132        buf.append("InnerClasses(");
133        buf.append(innerClasses.length);
134        buf.append("):\n");
135        for (final InnerClass inner_class : innerClasses) {
136            buf.append(inner_class.toString(super.getConstantPool())).append("\n");
137        }
138        return buf.substring(0, buf.length()-1); // remove the last newline
139    }
140
141
142    /**
143     * @return deep copy of this attribute
144     */
145    @Override
146    public Attribute copy( final ConstantPool _constant_pool ) {
147        // TODO this could be recoded to use a lower level constructor after creating a copy of the inner classes
148        final InnerClasses c = (InnerClasses) clone();
149        c.innerClasses = new InnerClass[innerClasses.length];
150        for (int i = 0; i < innerClasses.length; i++) {
151            c.innerClasses[i] = innerClasses[i].copy();
152        }
153        c.setConstantPool(_constant_pool);
154        return c;
155    }
156}