    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 */
    017package org.apache.bcel.classfile;
    018
    019import java.io.DataInput;
    020import java.io.DataOutputStream;
    021import java.io.IOException;
    022
    023import org.apache.bcel.Const;
    024
    025/**
    026 * This class is derived from <em>Attribute</em> and represents a reference to the source file of this class. At most
    027 * one SourceFile attribute should appear per classfile. The intention of this class is that it is instantiated from the
    028 * <em>Attribute.readAttribute()</em> method.
    029 *
    030 * @see Attribute
    031 */
    032public final class SourceFile extends Attribute {
    033
    034    private int sourceFileIndex;
    035
    036    /**
    037     * Construct object from input stream.
    038     *
    039     * @param nameIndex Index in constant pool to CONSTANT_Utf8
    040     * @param length Content length in bytes
    041     * @param input Input stream
    042     * @param constantPool Array of constants
    043     * @throws IOException if an I/O error occurs.
    044     */
    045    SourceFile(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
    046        this(nameIndex, length, input.readUnsignedShort(), constantPool);
    047    }
    048
    049    /**
    050     * @param nameIndex Index in constant pool to CONSTANT_Utf8, which should represent the string "SourceFile".
    051     * @param length Content length in bytes, the value should be 2.
    052     * @param constantPool The constant pool that this attribute is associated with.
    053     * @param sourceFileIndex Index in constant pool to CONSTANT_Utf8. This string will be interpreted as the name of the
    054     *        file from which this class was compiled. It will not be interpreted as indicating the name of the directory
    055     *        contqining the file or an absolute path; this information has to be supplied the consumer of this attribute -
    056     *        in many cases, the JVM.
    057     */
    058    public SourceFile(final int nameIndex, final int length, final int sourceFileIndex, final ConstantPool constantPool) {
    059        super(Const.ATTR_SOURCE_FILE, nameIndex, length, constantPool);
    060        this.sourceFileIndex = sourceFileIndex;
    061    }
    062
    063    /**
    064     * Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a
    065     * physical copy.
    066     */
    067    public SourceFile(final SourceFile c) {
    068        this(c.getNameIndex(), c.getLength(), c.getSourceFileIndex(), c.getConstantPool());
    069    }
    070
    071    /**
    072     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
    073     * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
    074     *
    075     * @param v Visitor object
    076     */
    077    @Override
    078    public void accept(final Visitor v) {
    079        v.visitSourceFile(this);
    080    }
    081
    082    /**
    083     * @return deep copy of this attribute
    084     */
    085    @Override
    086    public Attribute copy(final ConstantPool constantPool) {
    087        return (Attribute) clone();
    088    }
    089
    090    /**
    091     * Dump source file attribute to file stream in binary format.
    092     *
    093     * @param file Output file stream
    094     * @throws IOException if an I/O error occurs.
    095     */
    096    @Override
    097    public void dump(final DataOutputStream file) throws IOException {
    098        super.dump(file);
    099        file.writeShort(sourceFileIndex);
    100    }
    101
    102    /**
    103     * @return Index in constant pool of source file name.
    104     */
    105    public int getSourceFileIndex() {
    106        return sourceFileIndex;
    107    }
    108
    109    /**
    110     * @return Source file name.
    111     */
    112    public String getSourceFileName() {
    113        return super.getConstantPool().getConstantUtf8(sourceFileIndex).getBytes();
    114    }
    115
    116    /**
    117     * @param sourceFileIndex
    118     */
    119    public void setSourceFileIndex(final int sourceFileIndex) {
    120        this.sourceFileIndex = sourceFileIndex;
    121    }
    122
    123    /**
    124     * @return String representation
    125     */
    126    @Override
    127    public String toString() {
    128        return "SourceFile: " + getSourceFileName();
    129    }
    130}