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Java > Open Source Codes > com > sun > org > apache > bcel > internal > classfile > Unknown


1 package com.sun.org.apache.bcel.internal.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 com.sun.org.apache.bcel.internal.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
64  * from the <em>Attribute.readAttribute()</em> method.
65  *
66  * @version $Id: Unknown.java,v 1.1.1.1 2001/10/29 20:00:04 jvanzyl Exp $
67  * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
68  */
69 public final class Unknown extends Attribute {
70   private byte[] bytes;
71   private String JavaDoc name;
72
73   private static HashMap unknown_attributes = new HashMap();
74
75   /** @return array of unknown attributes, but just one for each kind.
76    */
77   static Unknown[] getUnknownAttributes() {
78     Unknown[] unknowns = new Unknown[unknown_attributes.size()];
79     Iterator entries = unknown_attributes.values().iterator();
80
81     for(int i=0; entries.hasNext(); i++)
82       unknowns[i] = (Unknown)entries.next();
83
84     unknown_attributes.clear();
85     return unknowns;
86   }
87
88   /**
89    * Initialize from another object. Note that both objects use the same
90    * references (shallow copy). Use clone() for a physical copy.
91    */
92   public Unknown(Unknown c) {
93     this(c.getNameIndex(), c.getLength(), c.getBytes(), c.getConstantPool());
94   }
95
96   /**
97    * Create a non-standard attribute.
98    *
99    * @param name_index Index in constant pool
100    * @param length Content length in bytes
101    * @param bytes Attribute contents
102    * @param constant_pool Array of constants
103    */
104   public Unknown(int name_index, int length, byte[] bytes,
105          ConstantPool constant_pool)
106   {
107     super(Constants.ATTR_UNKNOWN, name_index, length, constant_pool);
108     this.bytes = bytes;
109
110     name = ((ConstantUtf8)constant_pool.getConstant(name_index,
111                             Constants.CONSTANT_Utf8)).getBytes();
112     unknown_attributes.put(name, this);
113   }
114
115   /**
116    * Construct object from file stream.
117    * @param name_index Index in constant pool
118    * @param length Content length in bytes
119    * @param file Input stream
120    * @param constant_pool Array of constants
121    * @throw IOException
122    */
123   Unknown(int name_index, int length, DataInputStream file,
124       ConstantPool constant_pool)
125        throws IOException
126   {
127     this(name_index, length, (byte [])null, constant_pool);
128
129     if(length > 0) {
130       bytes = new byte[length];
131       file.readFully(bytes);
132     }
133   }
134
135   /**
136    * Called by objects that are traversing the nodes of the tree implicitely
137    * defined by the contents of a Java class. I.e., the hierarchy of methods,
138    * fields, attributes, etc. spawns a tree of objects.
139    *
140    * @param v Visitor object
141    */
142   public void accept(Visitor v) {
143     v.visitUnknown(this);
144   }
145   /**
146    * Dump unknown bytes to file stream.
147    *
148    * @param file Output file stream
149    * @throw IOException
150    */
151   public final void dump(DataOutputStream file) throws IOException
152   {
153     super.dump(file);
154     if(length > 0)
155       file.write(bytes, 0, length);
156   }
157   /**
158    * @return data bytes.
159    */
160   public final byte[] getBytes() { return bytes; }
161
162   /**
163    * @return name of attribute.
164    */
165   public final String JavaDoc getName() { return name; }
166
167   /**
168    * @param bytes.
169    */
170   public final void setBytes(byte[] bytes) {
171     this.bytes = bytes;
172   }
173
174   /**
175    * @return String representation.
176    */
177   public final String JavaDoc toString() {
178     if(length == 0 || bytes == null)
179       return "(Unknown attribute " + name + ")";
180
181     String JavaDoc hex;
182     if(length > 10) {
183       byte[] tmp = new byte[10];
184       System.arraycopy(bytes, 0, tmp, 0, 10);
185       hex = Utility.toHexString(tmp) + "... (truncated)";
186     }
187     else
188       hex = Utility.toHexString(bytes);
189
190     return "(Unknown attribute " + name + ": " + hex + ")";
191   }
192
193   /**
194    * @return deep copy of this attribute
195    */
196   public Attribute copy(ConstantPool constant_pool) {
197     Unknown c = (Unknown)clone();
198
199     if(bytes != null)
200       c.bytes = (byte[])bytes.clone();
201
202     c.constant_pool = constant_pool;
203     return c;
204   }
205 }
206
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