DataEntryRewriter.java revision cfead78069f3dc32998dc118ee08cab3867acea2 
1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2011 Eric Lafortune (eric@graphics.cornell.edu)
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the Free
9 * Software Foundation; either version 2 of the License, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21package proguard.io;
22
23import proguard.classfile.*;
24
25import java.io.*;
26
27/**
28 * This DataEntryReader writes the resource data entries that it reads to a
29 * given DataEntryWriter, updating their contents based on the renamed classes
30 * in the given ClassPool.
31 *
32 * @author Eric Lafortune
33 */
34public class DataEntryRewriter extends DataEntryCopier
35{
36    private final ClassPool classPool;
37
38
39    /**
40     * Creates a new DataEntryRewriter.
41     */
42    public DataEntryRewriter(ClassPool       classPool,
43                             DataEntryWriter dataEntryWriter)
44    {
45        super(dataEntryWriter);
46
47        this.classPool = classPool;
48    }
49
50
51    // Implementations for DataEntryCopier.
52
53    protected void copyData(InputStream  inputStream,
54                            OutputStream outputStream)
55    throws IOException
56    {
57        Reader reader = new BufferedReader(new InputStreamReader(inputStream));
58        Writer writer = new BufferedWriter(new OutputStreamWriter(outputStream));
59
60        copyData(reader, writer);
61
62        writer.flush();
63        outputStream.flush();
64    }
65
66
67    /**
68     * Copies all data that it can read from the given reader to the given
69     * writer.
70     */
71    protected void copyData(Reader reader,
72                            Writer writer)
73    throws IOException
74    {
75        StringBuffer word = new StringBuffer();
76
77        while (true)
78        {
79            int i = reader.read();
80            if (i < 0)
81            {
82                break;
83            }
84
85            // Is the character part of a word?
86            char c = (char)i;
87            if (Character.isJavaIdentifierPart(c) ||
88                c == '.' ||
89                c == '-')
90            {
91                // Collect the characters in this word.
92                word.append(c);
93            }
94            else
95            {
96                // Write out the updated word, if any.
97                writeUpdatedWord(writer, word.toString());
98                word.setLength(0);
99
100                // Write out the character that terminated it.
101                writer.write(c);
102            }
103        }
104
105        // Write out the final word.
106        writeUpdatedWord(writer, word.toString());
107    }
108
109
110    // Small utility methods.
111
112    /**
113     * Writes the given word to the given writer, after having adapted it,
114     * based on the renamed class names.
115     */
116    private void writeUpdatedWord(Writer writer, String word)
117    throws IOException
118    {
119        if (word.length() > 0)
120        {
121            String newWord = word;
122
123            boolean containsDots = word.indexOf('.') >= 0;
124
125            // Replace dots by forward slashes.
126            String className = containsDots ?
127                word.replace('.', ClassConstants.INTERNAL_PACKAGE_SEPARATOR) :
128                word;
129
130            // Find the class corrsponding to the word.
131            Clazz clazz = classPool.getClass(className);
132            if (clazz != null)
133            {
134                // Update the word if necessary.
135                String newClassName = clazz.getName();
136                if (!className.equals(newClassName))
137                {
138                    // Replace forward slashes by dots.
139                    newWord = containsDots ?
140                        newClassName.replace(ClassConstants.INTERNAL_PACKAGE_SEPARATOR, '.') :
141                        newClassName;
142                }
143            }
144
145            writer.write(newWord);
146        }
147    }
148}
149