Access


1   /*
2    * Access.java
3    *
4    * The contents of this file are subject to the terms of the Common Development
5    * and Distribution License (the License). You may not use this file except in
6    * compliance with the License.
7    *
8    * You can obtain a copy of the License at http://www.netbeans.org/cddl.html
9    * or http://www.netbeans.org/cddl.txt.
10   *
11   * When distributing Covered Code, include this CDDL Header Notice in each file
12   * and include the License file at http://www.netbeans.org/cddl.txt.
13   * If applicable, add the following below the CDDL Header, with the fields
14   * enclosed by brackets [] replaced by your own identifying information:
15   * "Portions Copyrighted [year] [name of copyright owner]"
16   *
17   * The Original Software is NetBeans. The Initial Developer of the Original
18   * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
19   * Microsystems, Inc. All Rights Reserved.
20   *
21   * Contributor(s): Thomas Ball
22   *
23   * Version: $Revision: 1.3 $
24   */
25  
26  package org.netbeans.modules.classfile;
27  
28  /**
29   * A utility class defining access flags and access utility methods.
30   * Access flags are as defined by the Java Virtual Machine Specification
31   * Second Edition, tables 4.1, 4.4, 4.5 and 4.7.
32   *
33   * @author Thomas Ball
34   */
35  public class Access {
36  
37      /** Declared public, may be accessed from outside its package. */
38      public static final int PUBLIC       = 0x0001;
39  
40      /** Declared private, usable only within the defining class. */
41      public static final int PRIVATE      = 0x0002;
42  
43      /** Declared protected, may be accessed within subclasses. */
44      public static final int PROTECTED    = 0x0004;
45  
46      /** Declared static. */
47      public static final int STATIC       = 0x0008;
48  
49      /**
50       * Declared final.  For classes this means no subclassing allowed.
51       * For fields it means no further assignment allowed after initialization.
52       * For methods it means that the method cannot be overridden.
53       */
54      public static final int FINAL        = 0x0010;
55  
56      /** Declared synchronized; invocation is wrapped in a monitor lock. */
57      public static final int SYNCHRONIZED = 0x0020;
58  
59      /**
60       * Treat superclass methods specially when invoked by the
61       * <i>invokespecial</i> instruction.  This access only applies to
62       * classes, and shares the same value as SYNCHRONIZED.
63       */
64      public static final int SUPER        = 0x0020;
65  
66      /** Declared volatile; cannot be cached. */
67      public static final int VOLATILE     = 0x0040;
68  
69      /** A bridge method, generated by the compiler. */
70      public static final int BRIDGE       = 0x0040;
71  
72      /** 
73       * Declared transient; not written or read by a persistent object 
74       * manager 
75       */
76      public static final int TRANSIENT    = 0x0080;
77  
78      /** Declared with a variable number of arguments. */
79      public static final int VARARGS      = 0x0080;
80  
81      /** Declared native; implemented in a language other than Java. */
82      public static final int NATIVE       = 0x0100;
83  
84      /** Is an interface, not a class. */
85      public static final int INTERFACE    = 0x0200;
86  
87      /** Declared abstract; must not be instantiated. */
88      public static final int ABSTRACT     = 0x0400;
89  
90      /** Declared strictfp; floating point mode is FP-strict. */
91      public static final int STRICT       = 0x0800;
92  
93      /** Declared synthetic, not present in the source file. */
94      public static final int SYNTHETIC    = 0x1000;
95  
96      /** Declared as an annotation type. */
97      public static final int ANNOTATION   = 0x2000;
98  
99      /** 
100      * For classes, declared as an enum type.  For fields, declared as
101      * an element of an enum.
102      */
103     public static final int ENUM         = 0x4000;
104 
105     /**
106      * Return a text representation for a given set of access flags.  
107      * Here are some examples:
108      * <DL>
109      *  <DD><CODE>"public static final"</CODE>,</DD>
110      *  <DD><CODE>"package private"</CODE>, or</DD>
111      *  <DD><CODE>"protected transient"</CODE>.</DD>
112      * </DL>
113      * Note: only access flags that map to Java modifier keywords are returned.
114      * @param access the mask of flags denoting access permission.
115      * @return a text representation of the access flags.
116      */
117     public static String   toString(int access) {
118         StringBuffer   sb = new StringBuffer  ();
119         if ((access & PUBLIC) == PUBLIC)
120             sb.append("public "); //NOI18N
121         if ((access & PRIVATE) == PRIVATE)
122             sb.append("private "); //NOI18N
123         if ((access & PROTECTED) == PROTECTED)
124             sb.append("protected "); //NOI18N
125         if ((access & (PUBLIC | PRIVATE | PROTECTED)) == 0)
126             sb.append("package private "); //NOI18N
127         if ((access & STATIC) == STATIC)
128             sb.append("static "); //NOI18N
129         if ((access & FINAL) == FINAL)
130             sb.append("final "); //NOI18N
131         if ((access & SYNCHRONIZED) == SYNCHRONIZED)
132             sb.append("synchronized "); //NOI18N
133         if ((access & VOLATILE) == VOLATILE)
134             sb.append("volatile "); //NOI18N
135         if ((access & TRANSIENT) == TRANSIENT)
136             sb.append("transient "); //NOI18N
137         if ((access & NATIVE) == NATIVE)
138             sb.append("native "); //NOI18N
139         if ((access & ABSTRACT) == ABSTRACT)
140             sb.append("abstract "); //NOI18N
141         if ((access & STRICT) == STRICT)
142             sb.append("strict "); //NOI18N
143 
144         // trim trailing space
145         return sb.substring(0, sb.length()-1);
146     }
147 
148     public static boolean isStatic(int access) {
149         return ((access & STATIC) == STATIC);
150     }
151 
152     public static final boolean isPublic(int access) {
153         return ((access & PUBLIC) == PUBLIC);
154     }
155 
156     public static final boolean isProtected(int access) {
157         return ((access & PROTECTED) == PROTECTED);
158     }
159 
160     public static final boolean isPackagePrivate(int access) {
161         return ((access & (PUBLIC | PRIVATE | PROTECTED)) == 0);
162     }
163 
164     public static final boolean isPrivate(int access) {
165         return ((access & PRIVATE) == PRIVATE);
166     }
167 
168     private Access() {
169         // don't allow instantiation
170     }
171 }
172
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