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1 package org.apache.bcel.classfile; 2 3 /* ==================================================================== 4 * The Apache Software License, Version 1.1 5 * 6 * Copyright (c) 2001 The Apache Software Foundation. All rights 7 * reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. The end-user documentation included with the redistribution, 22 * if any, must include the following acknowledgment: 23 * "This product includes software developed by the 24 * Apache Software Foundation (http://www.apache.org/)." 25 * Alternately, this acknowledgment may appear in the software itself, 26 * if and wherever such third-party acknowledgments normally appear. 27 * 28 * 4. The names "Apache" and "Apache Software Foundation" and 29 * "Apache BCEL" must not be used to endorse or promote products 30 * derived from this software without prior written permission. For 31 * written permission, please contact apache@apache.org. 32 * 33 * 5. Products derived from this software may not be called "Apache", 34 * "Apache BCEL", nor may "Apache" appear in their name, without 35 * prior written permission of the Apache Software Foundation. 36 * 37 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 38 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 39 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 40 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 41 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 42 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 43 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 44 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 45 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 47 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 * ==================================================================== 50 * 51 * This software consists of voluntary contributions made by many 52 * individuals on behalf of the Apache Software Foundation. For more 53 * information on the Apache Software Foundation, please see 54 * <http://www.apache.org/>;. 55 */ 56 57 import org.apache.bcel.Constants; 58 import java.io.*; 59 import java.util.*; 60 61 /*** 62 * This class represents a reference to an unknown (i.e., 63 * application-specific) attribute of a class. It is instantiated from the 64 * <em>Attribute.readAttribute()</em> method. Applications that need to 65 * read in application-specific attributes should create an <a 66 * href="./AttributeReader.html">AttributeReader</a> implementation and 67 * attach it via <a 68 * href="./Attribute.html#addAttributeReader(java.lang.String, 69 * org.apache.bcel.classfile.AttributeReader)">Attribute.addAttributeReader</a>. 70 71 * 72 * @version $Id: Unknown.java,v 1.3 2002/03/11 16:16:35 mdahm Exp $ 73 * @see org.apache.bcel.classfile.Attribute 74 * @see org.apache.bcel.classfile.AttributeReader 75 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> 76 */ 77 public final class Unknown extends Attribute { 78 private byte[] bytes; 79 private String name; 80 81 private static HashMap unknown_attributes = new HashMap(); 82 83 /*** @return array of unknown attributes, but just one for each kind. 84 */ 85 static Unknown[] getUnknownAttributes() { 86 Unknown[] unknowns = new Unknown[unknown_attributes.size()]; 87 Iterator entries = unknown_attributes.values().iterator(); 88 89 for(int i=0; entries.hasNext(); i++) 90 unknowns[i] = (Unknown)entries.next(); 91 92 unknown_attributes.clear(); 93 return unknowns; 94 } 95 96 /*** 97 * Initialize from another object. Note that both objects use the same 98 * references (shallow copy). Use clone() for a physical copy. 99 */ 100 public Unknown(Unknown c) { 101 this(c.getNameIndex(), c.getLength(), c.getBytes(), c.getConstantPool()); 102 } 103 104 /*** 105 * Create a non-standard attribute. 106 * 107 * @param name_index Index in constant pool 108 * @param length Content length in bytes 109 * @param bytes Attribute contents 110 * @param constant_pool Array of constants 111 */ 112 public Unknown(int name_index, int length, byte[] bytes, 113 ConstantPool constant_pool) 114 { 115 super(Constants.ATTR_UNKNOWN, name_index, length, constant_pool); 116 this.bytes = bytes; 117 118 name = ((ConstantUtf8)constant_pool.getConstant(name_index, 119 Constants.CONSTANT_Utf8)).getBytes(); 120 unknown_attributes.put(name, this); 121 } 122 123 /*** 124 * Construct object from file stream. 125 * @param name_index Index in constant pool 126 * @param length Content length in bytes 127 * @param file Input stream 128 * @param constant_pool Array of constants 129 * @throws IOException 130 */ 131 Unknown(int name_index, int length, DataInputStream file, 132 ConstantPool constant_pool) 133 throws IOException 134 { 135 this(name_index, length, (byte [])null, constant_pool); 136 137 if(length > 0) { 138 bytes = new byte[length]; 139 file.readFully(bytes); 140 } 141 } 142 143 /*** 144 * Called by objects that are traversing the nodes of the tree implicitely 145 * defined by the contents of a Java class. I.e., the hierarchy of methods, 146 * fields, attributes, etc. spawns a tree of objects. 147 * 148 * @param v Visitor object 149 */ 150 public void accept(Visitor v) { 151 v.visitUnknown(this); 152 } 153 /*** 154 * Dump unknown bytes to file stream. 155 * 156 * @param file Output file stream 157 * @throws IOException 158 */ 159 public final void dump(DataOutputStream file) throws IOException 160 { 161 super.dump(file); 162 if(length > 0) 163 file.write(bytes, 0, length); 164 } 165 /*** 166 * @return data bytes. 167 */ 168 public final byte[] getBytes() { return bytes; } 169 170 /*** 171 * @return name of attribute. 172 */ 173 public final String getName() { return name; } 174 175 /*** 176 * @param bytes. 177 */ 178 public final void setBytes(byte[] bytes) { 179 this.bytes = bytes; 180 } 181 182 /*** 183 * @return String representation. 184 */ 185 public final String toString() { 186 if(length == 0 || bytes == null) 187 return "(Unknown attribute " + name + ")"; 188 189 String hex; 190 if(length > 10) { 191 byte[] tmp = new byte[10]; 192 System.arraycopy(bytes, 0, tmp, 0, 10); 193 hex = Utility.toHexString(tmp) + "... (truncated)"; 194 } 195 else 196 hex = Utility.toHexString(bytes); 197 198 return "(Unknown attribute " + name + ": " + hex + ")"; 199 } 200 201 /*** 202 * @return deep copy of this attribute 203 */ 204 public Attribute copy(ConstantPool constant_pool) { 205 Unknown c = (Unknown)clone(); 206 207 if(bytes != null) 208 c.bytes = (byte[])bytes.clone(); 209 210 c.constant_pool = constant_pool; 211 return c; 212 } 213 }

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