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
020/**
021 * Unknown (non-standard) attributes may be read via user-defined factory objects that can be registered with the
022 * Attribute.addAttributeReader method. These factory objects should implement this interface.
023 *
024 * @see Attribute
025 *
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 name_index An index into the constant pool, indexing a ConstantUtf8 that represents the name of the attribute.
037     *
038     * @param length The length of the data contained in the attribute. This is written into the constant pool and should
039     *        agree with what the factory expects the length to be.
040     *
041     * @param file This is the data input stream that the factory needs to read its data from.
042     *
043     * @param constant_pool This is the constant pool associated with the Attribute that we are constructing.
044     *
045     * @return The user-defined AttributeReader should take this data and use it to construct an attribute. In the case of
046     *         errors, a null can be returned which will cause the parsing of the class file to fail.
047     *
048     * @see Attribute#addAttributeReader( String, AttributeReader )
049     */
050    Attribute createAttribute(int name_index, int length, java.io.DataInputStream file, ConstantPool constant_pool);
051}