1 /* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5 package com.sun.org.apache.bcel.internal.classfile; 6 7 /* ==================================================================== 8 * The Apache Software License, Version 1.1 9 * 10 * Copyright (c) 2001 The Apache Software Foundation. All rights 11 * reserved. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in 22 * the documentation and/or other materials provided with the 23 * distribution. 24 * 25 * 3. The end-user documentation included with the redistribution, 26 * if any, must include the following acknowledgment: 27 * "This product includes software developed by the 28 * Apache Software Foundation (http://www.apache.org/)." 29 * Alternately, this acknowledgment may appear in the software itself, 30 * if and wherever such third-party acknowledgments normally appear. 31 * 32 * 4. The names "Apache" and "Apache Software Foundation" and 33 * "Apache BCEL" must not be used to endorse or promote products 34 * derived from this software without prior written permission. For 35 * written permission, please contact apache@apache.org. 36 * 37 * 5. Products derived from this software may not be called "Apache", 38 * "Apache BCEL", nor may "Apache" appear in their name, without 39 * prior written permission of the Apache Software Foundation. 40 * 41 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 42 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 52 * SUCH DAMAGE. 53 * ==================================================================== 54 * 55 * This software consists of voluntary contributions made by many 56 * individuals on behalf of the Apache Software Foundation. For more 57 * information on the Apache Software Foundation, please see 58 * <http://www.apache.org/>. 59 */ 60 61 import com.sun.org.apache.bcel.internal.Constants; 62 import java.io.*; 63 import java.util.*; 64 65 /** 66 * This class represents a reference to an unknown (i.e., 67 * application-specific) attribute of a class. It is instantiated from the 68 * <em>Attribute.readAttribute()</em> method. Applications that need to 69 * read in application-specific attributes should create an <a 70 * href="./AttributeReader.html">AttributeReader</a> implementation and 71 * attach it via <a 72 * href="./Attribute.html#addAttributeReader(java.lang.String, 73 * com.sun.org.apache.bcel.internal.classfile.AttributeReader)">Attribute.addAttributeReader</a>. 74 75 * 76 * @see com.sun.org.apache.bcel.internal.classfile.Attribute 77 * @see com.sun.org.apache.bcel.internal.classfile.AttributeReader 78 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> 79 */ 80 public final class Unknown extends Attribute { 81 private byte[] bytes; 82 private String name; 83 84 private static HashMap unknown_attributes = new HashMap(); 85 86 /** @return array of unknown attributes, but just one for each kind. 87 */ 88 static Unknown[] getUnknownAttributes() { 89 Unknown[] unknowns = new Unknown[unknown_attributes.size()]; 90 Iterator entries = unknown_attributes.values().iterator(); 91 92 for(int i=0; entries.hasNext(); i++) 93 unknowns[i] = (Unknown)entries.next(); 94 95 unknown_attributes.clear(); 96 return unknowns; 97 } 98 99 /** 100 * Initialize from another object. Note that both objects use the same 101 * references (shallow copy). Use clone() for a physical copy. 102 */ 103 public Unknown(Unknown c) { 104 this(c.getNameIndex(), c.getLength(), c.getBytes(), c.getConstantPool()); 105 } 106 107 /** 108 * Create a non-standard attribute. 109 * 110 * @param name_index Index in constant pool 111 * @param length Content length in bytes 112 * @param bytes Attribute contents 113 * @param constant_pool Array of constants 114 */ 115 public Unknown(int name_index, int length, byte[] bytes, 116 ConstantPool constant_pool) 117 { 118 super(Constants.ATTR_UNKNOWN, name_index, length, constant_pool); 119 this.bytes = bytes; 120 121 name = ((ConstantUtf8)constant_pool.getConstant(name_index, 122 Constants.CONSTANT_Utf8)).getBytes(); 123 unknown_attributes.put(name, this); 124 } 125 126 /** 127 * Construct object from file stream. 128 * @param name_index Index in constant pool 129 * @param length Content length in bytes 130 * @param file Input stream 131 * @param constant_pool Array of constants 132 * @throws IOException 133 */ 134 Unknown(int name_index, int length, DataInputStream file, 135 ConstantPool constant_pool) 136 throws IOException 137 { 138 this(name_index, length, (byte [])null, constant_pool); 139 140 if(length > 0) { 141 bytes = new byte[length]; 142 file.readFully(bytes); 143 } 144 } 145 146 /** 147 * Called by objects that are traversing the nodes of the tree implicitely 148 * defined by the contents of a Java class. I.e., the hierarchy of methods, 149 * fields, attributes, etc. spawns a tree of objects. 150 * 151 * @param v Visitor object 152 */ 153 public void accept(Visitor v) { 154 v.visitUnknown(this); 155 } 156 /** 157 * Dump unknown bytes to file stream. 158 * 159 * @param file Output file stream 160 * @throws IOException 161 */ 162 public final void dump(DataOutputStream file) throws IOException 163 { 164 super.dump(file); 165 if(length > 0) 166 file.write(bytes, 0, length); 167 } 168 /** 169 * @return data bytes. 170 */ 171 public final byte[] getBytes() { return bytes; } 172 173 /** 174 * @return name of attribute. 175 */ 176 public final String getName() { return name; } 177 178 /** 179 * @param bytes. 180 */ 181 public final void setBytes(byte[] bytes) { 182 this.bytes = bytes; 183 } 184 185 /** 186 * @return String representation. 187 */ 188 public final String toString() { 189 if(length == 0 || bytes == null) 190 return "(Unknown attribute " + name + ")"; 191 192 String hex; 193 if(length > 10) { 194 byte[] tmp = new byte[10]; 195 System.arraycopy(bytes, 0, tmp, 0, 10); 196 hex = Utility.toHexString(tmp) + "... (truncated)"; 197 } 198 else 199 hex = Utility.toHexString(bytes); 200 201 return "(Unknown attribute " + name + ": " + hex + ")"; 202 } 203 204 /** 205 * @return deep copy of this attribute 206 */ 207 public Attribute copy(ConstantPool constant_pool) { 208 Unknown c = (Unknown)clone(); 209 210 if(bytes != null) 211 c.bytes = (byte[])bytes.clone(); 212 213 c.constant_pool = constant_pool; 214 return c; 215 } 216 }