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Java > Open Source Codes > proguard > io > ClassRewriter


1 /*
2  * ProGuard -- shrinking, optimization, obfuscation, and preverification
3  * of Java bytecode.
4  *
5  * Copyright (c) 2002-2007 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  */
21 package proguard.io;
22
23 import proguard.classfile.*;
24 import proguard.classfile.io.ProgramClassWriter;
25
26 import java.io.*;
27
28
29 /**
30  * This DataEntryReader reads class entries and writes their corresponding
31  * versions from the ClassPool to a given DataEntryWriter.
32  *
33  * @author Eric Lafortune
34  */
35 public class ClassRewriter implements DataEntryReader
36 {
37     private ClassPool classPool;
38     private DataEntryWriter dataEntryWriter;
39
40
41     public ClassRewriter(ClassPool classPool,
42                          DataEntryWriter dataEntryWriter)
43     {
44         this.classPool = classPool;
45         this.dataEntryWriter = dataEntryWriter;
46     }
47
48
49     // Implementations for DataEntryReader.
50
51     public void read(DataEntry dataEntry) throws IOException
52     {
53         String JavaDoc inputName = dataEntry.getName();
54         String JavaDoc className = inputName.substring(0, inputName.length() - ClassConstants.CLASS_FILE_EXTENSION.length());
55
56         // Find the modified class corrsponding to the input entry.
57 ProgramClass programClass = (ProgramClass)classPool.getClass(className);
58         if (programClass != null)
59         {
60             // Rename the data entry if necessary.
61 String JavaDoc newClassName = programClass.getName();
62             if (!className.equals(newClassName))
63             {
64                 dataEntry = new RenamedDataEntry(dataEntry, newClassName + ClassConstants.CLASS_FILE_EXTENSION);
65             }
66
67             // Get the output entry corresponding to this input entry.
68 OutputStream outputStream = dataEntryWriter.getOutputStream(dataEntry);
69             if (outputStream != null)
70             {
71                 // Write the class to the output entry.
72 DataOutputStream classOutputStream = new DataOutputStream(outputStream);
73
74                 new ProgramClassWriter(classOutputStream).visitProgramClass(programClass);
75
76                 classOutputStream.flush();
77             }
78         }
79     }
80 }
81
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