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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  import java.io.DataInput;
21  import java.io.DataOutputStream;
22  import java.io.IOException;
23  
24  import org.apache.bcel.Const;
25  
26  /**
27   * This class is derived from <em>Attribute</em> and represents a reference
28   * to the source file of this class.  At most one SourceFile attribute
29   * should appear per classfile.  The intention of this class is that it is
30   * instantiated from the <em>Attribute.readAttribute()</em> method.
31   *
32   * @version $Id: SourceFile.html 1018313 2017-09-18 09:03:04Z britter $
33   * @see     Attribute
34   */
35  public final class SourceFile extends Attribute {
36  
37      private int sourcefile_index;
38  
39  
40      /**
41       * Initialize from another object. Note that both objects use the same
42       * references (shallow copy). Use clone() for a physical copy.
43       */
44      public SourceFile(final SourceFile c) {
45          this(c.getNameIndex(), c.getLength(), c.getSourceFileIndex(), c.getConstantPool());
46      }
47  
48  
49      /**
50       * Construct object from input stream.
51       * @param name_index Index in constant pool to CONSTANT_Utf8
52       * @param length Content length in bytes
53       * @param input Input stream
54       * @param constant_pool Array of constants
55       * @throws IOException
56       */
57      SourceFile(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)
58              throws IOException {
59          this(name_index, length, input.readUnsignedShort(), constant_pool);
60      }
61  
62  
63      /**
64       * @param name_index Index in constant pool to CONSTANT_Utf8, which
65       * should represent the string "SourceFile".
66       * @param length Content length in bytes, the value should be 2.
67       * @param constant_pool The constant pool that this attribute is
68       * associated with.
69       * @param sourcefile_index Index in constant pool to CONSTANT_Utf8.  This
70       * string will be interpreted as the name of the file from which this
71       * class was compiled.  It will not be interpreted as indicating the name
72       * of the directory contqining the file or an absolute path; this
73       * information has to be supplied the consumer of this attribute - in
74       * many cases, the JVM.
75       */
76      public SourceFile(final int name_index, final int length, final int sourcefile_index, final ConstantPool constant_pool) {
77          super(Const.ATTR_SOURCE_FILE, name_index, length, constant_pool);
78          this.sourcefile_index = sourcefile_index;
79      }
80  
81  
82      /**
83       * Called by objects that are traversing the nodes of the tree implicitely
84       * defined by the contents of a Java class. I.e., the hierarchy of methods,
85       * fields, attributes, etc. spawns a tree of objects.
86       *
87       * @param v Visitor object
88       */
89      @Override
90      public void accept( final Visitor v ) {
91          v.visitSourceFile(this);
92      }
93  
94  
95      /**
96       * Dump source file attribute to file stream in binary format.
97       *
98       * @param file Output file stream
99       * @throws IOException
100      */
101     @Override
102     public final void dump( final DataOutputStream file ) throws IOException {
103         super.dump(file);
104         file.writeShort(sourcefile_index);
105     }
106 
107 
108     /**
109      * @return Index in constant pool of source file name.
110      */
111     public final int getSourceFileIndex() {
112         return sourcefile_index;
113     }
114 
115 
116     /**
117      * @param sourcefile_index
118      */
119     public final void setSourceFileIndex( final int sourcefile_index ) {
120         this.sourcefile_index = sourcefile_index;
121     }
122 
123 
124     /**
125      * @return Source file name.
126      */
127     public final String getSourceFileName() {
128         final ConstantUtf8 c = (ConstantUtf8) super.getConstantPool().getConstant(sourcefile_index,
129                 Const.CONSTANT_Utf8);
130         return c.getBytes();
131     }
132 
133 
134     /**
135      * @return String representation
136      */
137     @Override
138     public final String toString() {
139         return "SourceFile: " + getSourceFileName();
140     }
141 
142 
143     /**
144      * @return deep copy of this attribute
145      */
146     @Override
147     public Attribute copy( final ConstantPool _constant_pool ) {
148         return (Attribute) clone();
149     }
150 }