1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.bcel.classfile; 19 20 /** 21 * Unknown (non-standard) attributes may be read via user-defined factory 22 * objects that can be registered with the Attribute.addAttributeReader 23 * method. These factory objects should implement this interface. 24 * 25 * @see Attribute 26 * @version $Id$ 27 * @since 6.0 28 */ 29 public interface UnknownAttributeReader { 30 31 /** 32 * When this attribute reader is added via the static method Attribute.addAttributeReader, 33 * an attribute name is associated with it. As the class file parser parses attributes, 34 * it will call various AttributeReaders based on the name of the attributes it is constructing. 35 * 36 * @param name_index An index into the constant pool, indexing a ConstantUtf8 37 * that represents the name of the attribute. 38 * @param length The length of the data contained in the attribute. This is written 39 * into the constant pool and should agree with what the factory expects the length to be. 40 * @param file This is the data input that the factory needs to read its data from. 41 * @param constant_pool This is the constant pool associated with the Attribute that we are constructing. 42 * 43 * @return The user-defined AttributeReader should take this data and use 44 * it to construct an attribute. In the case of errors, a null can be 45 * returned which will cause the parsing of the class file to fail. 46 * 47 * @see Attribute#addAttributeReader(String, UnknownAttributeReader) 48 */ createAttribute( int name_index, int length, java.io.DataInput file, ConstantPool constant_pool )49 Attribute createAttribute( int name_index, int length, java.io.DataInput file, ConstantPool constant_pool ); 50 } 51