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Java > Open Source Codes > proguard > classfile > util > ExternalTypeEnumeration


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.classfile.util;
22
23 import proguard.classfile.*;
24
25
26 /**
27  * An <code>ExternalTypeEnumeration</code> provides an enumeration of all
28  * types listed in a given external descriptor string. The method name can
29  * be retrieved separately.
30  * <p>
31  * A <code>ExternalTypeEnumeration</code> object can be reused for processing
32  * different subsequent descriptors, by means of the <code>setDescriptor</code>
33  * method.
34  *
35  * @author Eric Lafortune
36  */
37 public class ExternalTypeEnumeration
38 {
39     private String JavaDoc descriptor;
40     private int index;
41
42
43     public ExternalTypeEnumeration(String JavaDoc descriptor)
44     {
45         setDescriptor(descriptor);
46     }
47
48
49     ExternalTypeEnumeration()
50     {
51     }
52
53
54     void setDescriptor(String JavaDoc descriptor)
55     {
56         this.descriptor = descriptor;
57
58         reset();
59     }
60
61
62     public void reset()
63     {
64         index = descriptor.indexOf(ClassConstants.EXTERNAL_METHOD_ARGUMENTS_OPEN) + 1;
65
66         if (index < 1)
67         {
68             throw new IllegalArgumentException JavaDoc("Missing opening parenthesis in descriptor ["+descriptor+"]");
69         }
70     }
71
72
73     public boolean hasMoreTypes()
74     {
75         return index < descriptor.length() - 1;
76     }
77
78
79     public String JavaDoc nextType()
80     {
81         int startIndex = index;
82
83         // Find the next separating comma.
84 index = descriptor.indexOf(ClassConstants.EXTERNAL_METHOD_ARGUMENTS_SEPARATOR,
85                                    startIndex);
86
87         // Otherwise find the closing parenthesis.
88 if (index < 0)
89         {
90             index = descriptor.indexOf(ClassConstants.EXTERNAL_METHOD_ARGUMENTS_CLOSE,
91                                        startIndex);
92             if (index < 0)
93             {
94                 throw new IllegalArgumentException JavaDoc("Missing closing parenthesis in descriptor ["+descriptor+"]");
95             }
96         }
97
98         return descriptor.substring(startIndex, index++).trim();
99     }
100
101
102     public String JavaDoc methodName()
103     {
104         return descriptor.substring(0, descriptor.indexOf(ClassConstants.EXTERNAL_METHOD_ARGUMENTS_OPEN)).trim();
105     }
106 }
107
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