001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.classfile;
019
020import java.io.DataInput;
021import java.io.DataOutputStream;
022import java.io.IOException;
023
024import org.apache.bcel.Const;
025
026/**
027 * This class is derived from <em>Attribute</em> and represents a reference
028 * to the source file of this class.  At most one SourceFile attribute
029 * should appear per classfile.  The intention of this class is that it is
030 * instantiated from the <em>Attribute.readAttribute()</em> method.
031 *
032 * @see     Attribute
033 */
034public final class SourceFile extends Attribute {
035
036    private int sourcefile_index;
037
038
039    /**
040     * Initialize from another object. Note that both objects use the same
041     * references (shallow copy). Use clone() for a physical copy.
042     */
043    public SourceFile(final SourceFile c) {
044        this(c.getNameIndex(), c.getLength(), c.getSourceFileIndex(), c.getConstantPool());
045    }
046
047
048    /**
049     * Construct object from input stream.
050     * @param name_index Index in constant pool to CONSTANT_Utf8
051     * @param length Content length in bytes
052     * @param input Input stream
053     * @param constant_pool Array of constants
054     * @throws IOException
055     */
056    SourceFile(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)
057            throws IOException {
058        this(name_index, length, input.readUnsignedShort(), constant_pool);
059    }
060
061
062    /**
063     * @param name_index Index in constant pool to CONSTANT_Utf8, which
064     * should represent the string "SourceFile".
065     * @param length Content length in bytes, the value should be 2.
066     * @param constant_pool The constant pool that this attribute is
067     * associated with.
068     * @param sourcefile_index Index in constant pool to CONSTANT_Utf8.  This
069     * string will be interpreted as the name of the file from which this
070     * class was compiled.  It will not be interpreted as indicating the name
071     * of the directory contqining the file or an absolute path; this
072     * information has to be supplied the consumer of this attribute - in
073     * many cases, the JVM.
074     */
075    public SourceFile(final int name_index, final int length, final int sourcefile_index, final ConstantPool constant_pool) {
076        super(Const.ATTR_SOURCE_FILE, name_index, length, constant_pool);
077        this.sourcefile_index = sourcefile_index;
078    }
079
080
081    /**
082     * Called by objects that are traversing the nodes of the tree implicitely
083     * defined by the contents of a Java class. I.e., the hierarchy of methods,
084     * fields, attributes, etc. spawns a tree of objects.
085     *
086     * @param v Visitor object
087     */
088    @Override
089    public void accept( final Visitor v ) {
090        v.visitSourceFile(this);
091    }
092
093
094    /**
095     * Dump source file attribute to file stream in binary format.
096     *
097     * @param file Output file stream
098     * @throws IOException
099     */
100    @Override
101    public void dump( final DataOutputStream file ) throws IOException {
102        super.dump(file);
103        file.writeShort(sourcefile_index);
104    }
105
106
107    /**
108     * @return Index in constant pool of source file name.
109     */
110    public int getSourceFileIndex() {
111        return sourcefile_index;
112    }
113
114
115    /**
116     * @param sourcefile_index
117     */
118    public void setSourceFileIndex( final int sourcefile_index ) {
119        this.sourcefile_index = sourcefile_index;
120    }
121
122
123    /**
124     * @return Source file name.
125     */
126    public String getSourceFileName() {
127        final ConstantUtf8 c = (ConstantUtf8) super.getConstantPool().getConstant(sourcefile_index,
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}