001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.bcel.classfile;
020
021/**
022 * Unknown (non-standard) attributes may be read via user-defined factory objects that can be registered with the
023 * Attribute.addAttributeReader method. These factory objects should implement this interface.
024 *
025 * @see Attribute
026 * @deprecated Use UnknownAttributeReader instead
027 */
028@java.lang.Deprecated
029public interface AttributeReader {
030
031    /**
032     * When this attribute reader is added via the static method Attribute.addAttributeReader, an attribute name is
033     * associated with it. As the class file parser parses attributes, it will call various AttributeReaders based on the
034     * name of the attributes it is constructing.
035     *
036     * @param nameIndex An index into the constant pool, indexing a ConstantUtf8 that represents the name of the attribute.
037     * @param length The length of the data contained in the attribute. This is written into the constant pool and should
038     *        agree with what the factory expects the length to be.
039     *
040     * @param file This is the data input stream that the factory needs to read its data from.
041     * @param constantPool This is the constant pool associated with the Attribute that we are constructing.
042     * @return The user-defined AttributeReader should take this data and use it to construct an attribute. In the case of
043     *         errors, a null can be returned which will cause the parsing of the class file to fail.
044     *
045     * @see Attribute#addAttributeReader( String, AttributeReader )
046     */
047    Attribute createAttribute(int nameIndex, int length, java.io.DataInputStream file, ConstantPool constantPool);
048}