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