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Java > Open Source Codes > org > apache > bcel > classfile > SourceFile


1 /*
2  * Copyright 2000-2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  *
16  */
17 package org.apache.bcel.classfile;
18
19 import java.io.DataInputStream JavaDoc;
20 import java.io.DataOutputStream JavaDoc;
21 import java.io.IOException JavaDoc;
22 import org.apache.bcel.Constants;
23
24 /**
25  * This class is derived from <em>Attribute</em> and represents a reference
26  * to the source file of this class. At most one SourceFile attribute
27  * should appear per classfile. The intention of this class is that it is
28  * instantiated from the <em>Attribute.readAttribute()</em> method.
29  *
30  * @version $Id: SourceFile.java 386056 2006-03-15 11:31:56Z tcurdt $
31  * @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
32  * @see Attribute
33  */
34 public final class SourceFile extends Attribute {
35
36     private int sourcefile_index;
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 c) {
44         this(c.getNameIndex(), c.getLength(), c.getSourceFileIndex(), c.getConstantPool());
45     }
46
47
48     /**
49      * Construct object from file stream.
50      * @param name_index Index in constant pool to CONSTANT_Utf8
51      * @param length Content length in bytes
52      * @param file Input stream
53      * @param constant_pool Array of constants
54      * @throws IOException
55      */
56     SourceFile(int name_index, int length, DataInputStream JavaDoc file, ConstantPool constant_pool)
57             throws IOException JavaDoc {
58         this(name_index, length, file.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 constant_pool The constant pool that this attribute is
67      * associated with.
68      * @param sourcefile_index 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(int name_index, int length, int sourcefile_index, ConstantPool constant_pool) {
76         super(Constants.ATTR_SOURCE_FILE, name_index, length, constant_pool);
77         this.sourcefile_index = sourcefile_index;
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     public void accept( Visitor v ) {
89         v.visitSourceFile(this);
90     }
91
92
93     /**
94      * Dump source file attribute to file stream in binary format.
95      *
96      * @param file Output file stream
97      * @throws IOException
98      */
99     public final void dump( DataOutputStream JavaDoc file ) throws IOException JavaDoc {
100         super.dump(file);
101         file.writeShort(sourcefile_index);
102     }
103
104
105     /**
106      * @return Index in constant pool of source file name.
107      */
108     public final int getSourceFileIndex() {
109         return sourcefile_index;
110     }
111
112
113     /**
114      * @param sourcefile_index
115      */
116     public final void setSourceFileIndex( int sourcefile_index ) {
117         this.sourcefile_index = sourcefile_index;
118     }
119
120
121     /**
122      * @return Source file name.
123      */
124     public final String JavaDoc getSourceFileName() {
125         ConstantUtf8 c = (ConstantUtf8) constant_pool.getConstant(sourcefile_index,
126                 Constants.CONSTANT_Utf8);
127         return c.getBytes();
128     }
129
130
131     /**
132      * @return String representation
133      */
134     public final String JavaDoc toString() {
135         return "SourceFile(" + getSourceFileName() + ")";
136     }
137
138
139     /**
140      * @return deep copy of this attribute
141      */
142     public Attribute copy( ConstantPool _constant_pool ) {
143         return (SourceFile) clone();
144     }
145 }
146
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