Decompiler


1   /* Decompiler Copyright (C) 2000-2002 Jochen Hoenicke.
2    *
3    * This program is free software; you can redistribute it and/or modify
4    * it under the terms of the GNU Lesser General Public License as published by
5    * the Free Software Foundation; either version 2, or (at your option)
6    * any later version.
7    *
8    * This program is distributed in the hope that it will be useful,
9    * but WITHOUT ANY WARRANTY; without even the implied warranty of
10   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11   * GNU General Public License for more details.
12   *
13   * You should have received a copy of the GNU Lesser General Public License
14   * along with this program; see the file COPYING.LESSER.  If not, write to
15   * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
16   *
17   * $Id: Decompiler.java,v 4.2.2.2 2002/05/28 17:34:03 hoenicke Exp $
18   */
19  
20  package jode.decompiler;
21  import jode.GlobalOptions;
22  import jode.bytecode.SearchPath;
23  import jode.bytecode.ClassInfo;
24  import java.io.File  ;
25  import java.io.PrintWriter  ;
26  import java.io.Writer  ;
27  import java.io.BufferedWriter  ;
28  
29  /**
30   * This is the interface that other java classes may use to decompile
31   * classes.  Feel free to use it in your own GNU GPL'ed project.
32   * Please tell me about your project.<br>
33   *
34   * Note that the GNU GPL doesn't allow you to use this interface in
35   * commercial programs. 
36   * 
37   * @author <a HREF="mailto:jochen@gnu.org">Jochen Hoenicke</a>
38   * @version 1.0
39   */
40  public class Decompiler {
41      private SearchPath searchPath = null;
42      private int importPackageLimit = ImportHandler.DEFAULT_PACKAGE_LIMIT;
43      private int importClassLimit = ImportHandler.DEFAULT_CLASS_LIMIT;
44  
45      /**
46       * We need a different pathSeparatorChar, since ':' (used for most
47       * UNIX System) is used a protocol separator in URLs.  
48       *
49       * We currently allow both pathSeparatorChar and
50       * altPathSeparatorChar and decide if it is a protocol separator
51       * by context.  
52       */
53      public static final char altPathSeparatorChar
54      = SearchPath.altPathSeparatorChar;
55  
56      /**
57       * Create a new decompiler.
58       */
59      public Decompiler() {
60      }
61      
62      /**
63       * Sets the class path.  Should be called once before decompile is
64       * called, otherwise the system class path is used.
65       * @param classpath A comma separated classpath.
66       * @exception NullPointerException if classpath is null.
67       * @see #setClassPath(String[])
68       */
69      public void setClassPath(String   classpath) {
70      searchPath = new SearchPath(classpath);
71      }
72  
73      /**
74       * Set the class path.  Should be called once before decompile is
75       * called, otherwise the system class path is used.
76       * @param classpath a non empty array of jar files and directories; 
77       *                  URLs are allowed, too.
78       * @exception NullPointerException if classpath is null.
79       * @exception IndexOutOfBoundsException if classpath array is empty.
80       * @see #setClassPath(String)
81       */
82      public void setClassPath(String  [] classpath) {
83      StringBuffer   sb = new StringBuffer  (classpath[0]);
84      for (int i = 1; i < classpath.length; i++)
85          sb.append(altPathSeparatorChar).append(classpath[i]);
86      searchPath = new SearchPath(sb.toString());
87      }
88  
89      private static final String  [] optionStrings = {
90      "lvt", "inner", "anonymous", "push", "pretty", "decrypt",
91      "onetime", "immediate", "verify", "contrafo"
92      };
93  
94      /**
95       * Set an option.
96       * @param option the option (pretty, style, decrypt, verify, etc.)
97       * @param value ("1"/"0" for on/off, "sun"/"gnu" for style)
98       * @exception IllegalArgumentException if option or value is invalid.
99       */
100     public void setOption(String   option, String   value) {
101     if (option.equals("style")) {
102         if (value.equals("gnu"))
103         Options.outputStyle = Options.GNU_STYLE;
104         else if (value.equals("sun"))
105         Options.outputStyle = Options.SUN_STYLE;
106         else if (value.equals("pascal"))
107         Options.outputStyle = Options.PASCAL_STYLE;
108         else
109         throw new IllegalArgumentException  ("Invalid style "+value);
110         return;
111     }
112     if (option.equals("import")) {
113         int comma = value.indexOf(',');
114         int packLimit = Integer.parseInt(value.substring(0, comma));
115         if (packLimit == 0)
116         packLimit = Integer.MAX_VALUE;
117         int clazzLimit = Integer.parseInt(value.substring(comma+1));
118         if (clazzLimit == 0)
119         clazzLimit = Integer.MAX_VALUE;
120         if (clazzLimit < 0 || packLimit < 0)
121         throw new IllegalArgumentException  
122             ("Option import doesn't allow negative parameters");
123         importPackageLimit = packLimit;
124         importClassLimit = clazzLimit;
125         return;
126     }
127     if (option.equals("verbose")) {
128         GlobalOptions.verboseLevel = Integer.parseInt(value);
129         return;
130     }
131     for (int i=0; i < optionStrings.length; i++) {
132         if (option.equals(optionStrings[i])) {
133         if (value.equals("0") 
134             || value.equals("off")
135             || value.equals("no"))
136             Options.options &= ~(1 << i);
137         else if (value.equals("1") 
138              || value.equals("on")
139              || value.equals("yes"))
140             Options.options |= 1 << i;
141         else
142             throw new IllegalArgumentException  ("Illegal value for "+
143                                option);
144         return;
145         }
146     }
147     throw new IllegalArgumentException  ("Illegal option: "+option);
148     }
149     
150     
151     /**
152      * Set the stream where copyright and warnings/errors are printed
153      * to.
154      * @param errorStream the error stream. Note that this is a
155      * PrintWriter, not a PrintStream (which are deprecated since 1.1).
156      */
157     public void setErr(PrintWriter   errorStream) {
158     GlobalOptions.err = errorStream;
159     }
160 
161    /**
162     * Decompile a class.
163     * @param className full-qualified classname, dot separated, e.g. 
164     *             "java.lang.Object"
165     * @param writer The stream where the decompiled code should be
166     *        written.  Hint:  Use a BufferedWriter for good performance.
167     * @param progress A progress listener (see below).  Null if you
168     *        don't need information about progress.
169     * @exception IllegalArgumentException if className isn't correct.
170     * @exception jode.jvm.VerifyException The code
171     *        isn't valid or a dependent class, needed for type
172     *        guessing, couldn't be found.
173     * @exception IOException if writer throws an exception.
174     * @exception RuntimeException If jode has a bug ;-)
175     */
176    public void decompile(String   className, Writer   writer,   
177              ProgressListener progress) 
178      throws java.io.IOException   {
179        if (searchPath == null) {
180        String   classPath = System.getProperty("java.class.path")
181            .replace(File.pathSeparatorChar, altPathSeparatorChar);
182        searchPath = new SearchPath(classPath);
183        }
184 
185        ClassInfo.setClassPath(searchPath);
186        ClassInfo clazz = ClassInfo.forName(className);
187        ImportHandler imports = new ImportHandler(importPackageLimit,
188                          importClassLimit);
189        TabbedPrintWriter tabbedWriter = 
190      new TabbedPrintWriter(writer, imports, false);
191        ClassAnalyzer clazzAna = new ClassAnalyzer(null, clazz, imports);
192        clazzAna.dumpJavaFile(tabbedWriter, progress);
193        writer.flush();
194    }
195 }
196
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