1 /*
   2  * reserved comment block
   3  * DO NOT REMOVE OR ALTER!
   4  */
   5 /*
   6  * Licensed to the Apache Software Foundation (ASF) under one or more
   7  * contributor license agreements.  See the NOTICE file distributed with
   8  * this work for additional information regarding copyright ownership.
   9  * The ASF licenses this file to You under the Apache License, Version 2.0
  10  * (the "License"); you may not use this file except in compliance with
  11  * the License.  You may obtain a copy of the License at
  12  *
  13  *      http://www.apache.org/licenses/LICENSE-2.0
  14  *
  15  * Unless required by applicable law or agreed to in writing, software
  16  * distributed under the License is distributed on an "AS IS" BASIS,
  17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18  * See the License for the specific language governing permissions and
  19  * limitations under the License.
  20  */
  21 
  22 package com.sun.org.apache.bcel.internal.classfile;
  23 
  24 import java.io.DataInput;
  25 import java.io.DataOutputStream;
  26 import java.io.IOException;
  27 
  28 import com.sun.org.apache.bcel.internal.Const;
  29 
  30 /**
  31  * This class is derived from <em>Attribute</em> and declares this class as
  32  * `synthetic', i.e., it needs special handling.  The JVM specification
  33  * states "A class member that does not appear in the source code must be
  34  * marked using a Synthetic attribute."  It may appear in the ClassFile
  35  * attribute table, a field_info table or a method_info table.  This class
  36  * is intended to be instantiated from the
  37  * <em>Attribute.readAttribute()</em> method.
  38  *
  39  * @version $Id$
  40  * @see     Attribute
  41  */
  42 public final class Synthetic extends Attribute {
  43 
  44     private byte[] bytes;
  45 
  46 
  47     /**
  48      * Initialize from another object. Note that both objects use the same
  49      * references (shallow copy). Use copy() for a physical copy.
  50      */
  51     public Synthetic(final Synthetic c) {
  52         this(c.getNameIndex(), c.getLength(), c.getBytes(), c.getConstantPool());
  53     }
  54 
  55 
  56     /**
  57      * @param name_index Index in constant pool to CONSTANT_Utf8, which
  58      * should represent the string "Synthetic".
  59      * @param length Content length in bytes - should be zero.
  60      * @param bytes Attribute contents
  61      * @param constant_pool The constant pool this attribute is associated
  62      * with.
  63      */
  64     public Synthetic(final int name_index, final int length, final byte[] bytes, final ConstantPool constant_pool) {
  65         super(Const.ATTR_SYNTHETIC, name_index, length, constant_pool);
  66         this.bytes = bytes;
  67     }
  68 
  69 
  70     /**
  71      * Construct object from input stream.
  72      *
  73      * @param name_index Index in constant pool to CONSTANT_Utf8
  74      * @param length Content length in bytes
  75      * @param input Input stream
  76      * @param constant_pool Array of constants
  77      * @throws IOException
  78      */
  79     Synthetic(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)
  80             throws IOException {
  81         this(name_index, length, (byte[]) null, constant_pool);
  82         if (length > 0) {
  83             bytes = new byte[length];
  84             input.readFully(bytes);
  85             System.err.println("Synthetic attribute with length > 0");
  86         }
  87     }
  88 
  89 
  90     /**
  91      * Called by objects that are traversing the nodes of the tree implicitely
  92      * defined by the contents of a Java class. I.e., the hierarchy of methods,
  93      * fields, attributes, etc. spawns a tree of objects.
  94      *
  95      * @param v Visitor object
  96      */
  97     @Override
  98     public void accept( final Visitor v ) {
  99         v.visitSynthetic(this);
 100     }
 101 
 102 
 103     /**
 104      * Dump source file attribute to file stream in binary format.
 105      *
 106      * @param file Output file stream
 107      * @throws IOException
 108      */
 109     @Override
 110     public final void dump( final DataOutputStream file ) throws IOException {
 111         super.dump(file);
 112         if (super.getLength() > 0) {
 113             file.write(bytes, 0, super.getLength());
 114         }
 115     }
 116 
 117 
 118     /**
 119      * @return data bytes.
 120      */
 121     public final byte[] getBytes() {
 122         return bytes;
 123     }
 124 
 125 
 126     /**
 127      * @param bytes
 128      */
 129     public final void setBytes( final byte[] bytes ) {
 130         this.bytes = bytes;
 131     }
 132 
 133 
 134     /**
 135      * @return String representation.
 136      */
 137     @Override
 138     public final String toString() {
 139         final StringBuilder buf = new StringBuilder("Synthetic");
 140         if (super.getLength() > 0) {
 141             buf.append(" ").append(Utility.toHexString(bytes));
 142         }
 143         return buf.toString();
 144     }
 145 
 146 
 147     /**
 148      * @return deep copy of this attribute
 149      */
 150     @Override
 151     public Attribute copy( final ConstantPool _constant_pool ) {
 152         final Synthetic c = (Synthetic) clone();
 153         if (bytes != null) {
 154             c.bytes = new byte[bytes.length];
 155             System.arraycopy(bytes, 0, c.bytes, 0, bytes.length);
 156         }
 157         c.setConstantPool(_constant_pool);
 158         return c;
 159     }
 160 }