- 001
/* - 002
* @(#)Modifier.java 1.28 05/11/17 - 003 *
- 004 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
- 005 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- 006
*/ - 007
- 008package java.lang.reflect;
- 009
- 010import java.security.AccessController;
- 011import sun.reflect.LangReflectAccess;
- 012import sun.reflect.ReflectionFactory;
- 013
- 014/**
- 015 * The Modifier class provides <code>static</code> methods and
- 016 * constants to decode class and member access modifiers. The sets of
- 017 * modifiers are represented as integers with distinct bit positions
- 018 * representing different modifiers. The values for the constants
- 019 * representing the modifiers are taken from <a
- 020 * href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/VMSpecTOC.doc.html"><i>The
- 021 * Java</i><sup><small>TM</small></sup> <i>Virtual Machine Specification, Second
- 022 * edition</i></a> tables
- 023 * <a href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#75734">4.1</a>,
- 024 * <a href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#88358">4.4</a>,
- 025 * <a href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#75568">4.5</a>, and
- 026 * <a href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/ClassFile.doc.html#88478">4.7</a>.
- 027 *
- 028 * @see Class#getModifiers()
- 029 * @see Member#getModifiers()
- 030 *
- 031 * @author Nakul Saraiya
- 032 * @author Kenneth Russell
- 033 */
- 034public
- 035class Modifier {
- 036
- 037 /*
- 038 * Bootstrapping protocol between java.lang and java.lang.reflect
- 039 * packages
- 040 */
- 041 static {
- 042 sun.reflect.ReflectionFactory factory =
- 043 (sun.reflect.ReflectionFactory) AccessController.doPrivileged(
- 044 new ReflectionFactory.GetReflectionFactoryAction()
- 045 );
- 046 factory.setLangReflectAccess(new java.lang.reflect.ReflectAccess());
- 047 }
- 048
- 049 /**
- 050 * Return <tt>true</tt> if the integer argument includes the
- 051 * <tt>public</tt> modifier, <tt>false</tt> otherwise.
- 052 *
- 053 * @param mod a set of modifiers
- 054 * @return <tt>true</tt> if <code>mod</code> includes the
- 055 * <tt>public</tt> modifier; <tt>false</tt> otherwise.
- 056 */
- 057 public static boolean isPublic(int mod) {
- 058 return (mod & PUBLIC) != 0;
- 059 }
- 060
- 061 /**
- 062 * Return <tt>true</tt> if the integer argument includes the
- 063 * <tt>private</tt> modifier, <tt>false</tt> otherwise.
- 064 *
- 065 * @param mod a set of modifiers
- 066 * @return <tt>true</tt> if <code>mod</code> includes the
- 067 * <tt>private</tt> modifier; <tt>false</tt> otherwise.
- 068 */
- 069 public static boolean isPrivate(int mod) {
- 070 return (mod & PRIVATE) != 0;
- 071 }
- 072
- 073 /**
- 074 * Return <tt>true</tt> if the integer argument includes the
- 075 * <tt>protected</tt> modifier, <tt>false</tt> otherwise.
- 076 *
- 077 * @param mod a set of modifiers
- 078 * @return <tt>true</tt> if <code>mod</code> includes the
- 079 * <tt>protected</tt> modifier; <tt>false</tt> otherwise.
- 080 */
- 081 public static boolean isProtected(int mod) {
- 082 return (mod & PROTECTED) != 0;
- 083 }
- 084
- 085 /**
- 086 * Return <tt>true</tt> if the integer argument includes the
- 087 * <tt>static</tt> modifier, <tt>false</tt> otherwise.
- 088 *
- 089 * @param mod a set of modifiers
- 090 * @return <tt>true</tt> if <code>mod</code> includes the
- 091 * <tt>static</tt> modifier; <tt>false</tt> otherwise.
- 092 */
- 093 public static boolean isStatic(int mod) {
- 094 return (mod & STATIC) != 0;
- 095 }
- 096
- 097 /**
- 098 * Return <tt>true</tt> if the integer argument includes the
- 099 * <tt>final</tt> modifier, <tt>false</tt> otherwise.
- 100 *
- 101 * @param mod a set of modifiers
- 102 * @return <tt>true</tt> if <code>mod</code> includes the
- 103 * <tt>final</tt> modifier; <tt>false</tt> otherwise.
- 104 */
- 105 public static boolean isFinal(int mod) {
- 106 return (mod & FINAL) != 0;
- 107 }
- 108
- 109 /**
- 110 * Return <tt>true</tt> if the integer argument includes the
- 111 * <tt>synchronized</tt> modifier, <tt>false</tt> otherwise.
- 112 *
- 113 * @param mod a set of modifiers
- 114 * @return <tt>true</tt> if <code>mod</code> includes the
- 115 * <tt>synchronized</tt> modifier; <tt>false</tt> otherwise.
- 116 */
- 117 public static boolean isSynchronized(int mod) {
- 118 return (mod & SYNCHRONIZED) != 0;
- 119 }
- 120
- 121 /**
- 122 * Return <tt>true</tt> if the integer argument includes the
- 123 * <tt>volatile</tt> modifier, <tt>false</tt> otherwise.
- 124 *
- 125 * @param mod a set of modifiers
- 126 * @return <tt>true</tt> if <code>mod</code> includes the
- 127 * <tt>volatile</tt> modifier; <tt>false</tt> otherwise.
- 128 */
- 129 public static boolean isVolatile(int mod) {
- 130 return (mod & VOLATILE) != 0;
- 131 }
- 132
- 133 /**
- 134 * Return <tt>true</tt> if the integer argument includes the
- 135 * <tt>transient</tt> modifier, <tt>false</tt> otherwise.
- 136 *
- 137 * @param mod a set of modifiers
- 138 * @return <tt>true</tt> if <code>mod</code> includes the
- 139 * <tt>transient</tt> modifier; <tt>false</tt> otherwise.
- 140 */
- 141 public static boolean isTransient(int mod) {
- 142 return (mod & TRANSIENT) != 0;
- 143 }
- 144
- 145 /**
- 146 * Return <tt>true</tt> if the integer argument includes the
- 147 * <tt>native</tt> modifier, <tt>false</tt> otherwise.
- 148 *
- 149 * @param mod a set of modifiers
- 150 * @return <tt>true</tt> if <code>mod</code> includes the
- 151 * <tt>native</tt> modifier; <tt>false</tt> otherwise.
- 152 */
- 153 public static boolean isNative(int mod) {
- 154 return (mod & NATIVE) != 0;
- 155 }
- 156
- 157 /**
- 158 * Return <tt>true</tt> if the integer argument includes the
- 159 * <tt>interface</tt> modifier, <tt>false</tt> otherwise.
- 160 *
- 161 * @param mod a set of modifiers
- 162 * @return <tt>true</tt> if <code>mod</code> includes the
- 163 * <tt>interface</tt> modifier; <tt>false</tt> otherwise.
- 164 */
- 165 public static boolean isInterface(int mod) {
- 166 return (mod & INTERFACE) != 0;
- 167 }
- 168
- 169 /**
- 170 * Return <tt>true</tt> if the integer argument includes the
- 171 * <tt>abstract</tt> modifier, <tt>false</tt> otherwise.
- 172 *
- 173 * @param mod a set of modifiers
- 174 * @return <tt>true</tt> if <code>mod</code> includes the
- 175 * <tt>abstract</tt> modifier; <tt>false</tt> otherwise.
- 176 */
- 177 public static boolean isAbstract(int mod) {
- 178 return (mod & ABSTRACT) != 0;
- 179 }
- 180
- 181 /**
- 182 * Return <tt>true</tt> if the integer argument includes the
- 183 * <tt>strictfp</tt> modifier, <tt>false</tt> otherwise.
- 184 *
- 185 * @param mod a set of modifiers
- 186 * @return <tt>true</tt> if <code>mod</code> includes the
- 187 * <tt>strictfp</tt> modifier; <tt>false</tt> otherwise.
- 188 */
- 189 public static boolean isStrict(int mod) {
- 190 return (mod & STRICT) != 0;
- 191 }
- 192
- 193 /**
- 194 * Return a string describing the access modifier flags in
- 195 * the specified modifier. For example:
- 196 * <blockquote><pre>
- 197 * public final synchronized strictfp
- 198 * </pre></blockquote>
- 199 * The modifier names are returned in an order consistent with the
- 200 * suggested modifier orderings given in <a
- 201 * href="http://java.sun.com/docs/books/jls/second_edition/html/j.title.doc.html"><em>The
- 202 * Java Language Specification, Second Edition</em></a> sections
- 203 * <a href="http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#21613">§8.1.1</a>,
- 204 * <a href="http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#78091">§8.3.1</a>,
- 205 * <a href="http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#78188">§8.4.3</a>,
- 206 * <a href="http://java.sun.com/docs/books/jls/second_edition/html/classes.doc.html#42018">§8.8.3</a>, and
- 207 * <a href="http://java.sun.com/docs/books/jls/second_edition/html/interfaces.doc.html#235947">§9.1.1</a>.
- 208 * The full modifier ordering used by this method is:
- 209 * <blockquote> <code>
- 210 * public protected private abstract static final transient
- 211 * volatile synchronized native strictfp
- 212 * interface </code> </blockquote>
- 213 * The <code>interface</code> modifier discussed in this class is
- 214 * not a true modifier in the Java language and it appears after
- 215 * all other modifiers listed by this method. This method may
- 216 * return a string of modifiers that are not valid modifiers of a
- 217 * Java entity; in other words, no checking is done on the
- 218 * possible validity of the combination of modifiers represented
- 219 * by the input.
- 220 *
- 221 * @param mod a set of modifiers
- 222 * @return a string representation of the set of modifiers
- 223 * represented by <code>mod</code>
- 224 */
- 225 public static String toString(int mod) {
- 226 StringBuffer sb = new StringBuffer();
- 227 int len;
- 228
- 229 if ((mod & PUBLIC) != 0) sb.append("public ");
- 230 if ((mod & PROTECTED) != 0) sb.append("protected ");
- 231 if ((mod & PRIVATE) != 0) sb.append("private ");
- 232
- 233 /* Canonical order */
- 234 if ((mod & ABSTRACT) != 0) sb.append("abstract ");
- 235 if ((mod & STATIC) != 0) sb.append("static ");
- 236 if ((mod & FINAL) != 0) sb.append("final ");
- 237 if ((mod & TRANSIENT) != 0) sb.append("transient ");
- 238 if ((mod & VOLATILE) != 0) sb.append("volatile ");
- 239 if ((mod & SYNCHRONIZED) != 0) sb.append("synchronized ");
- 240 if ((mod & NATIVE) != 0) sb.append("native ");
- 241 if ((mod & STRICT) != 0) sb.append("strictfp ");
- 242 if ((mod & INTERFACE) != 0) sb.append("interface ");
- 243
- 244 if ((len = sb.length()) > 0) /* trim trailing space */
- 245 return sb.toString().substring(0, len-1);
- 246 return "";
- 247 }
- 248
- 249 /*
- 250 * Access modifier flag constants from <em>The Java Virtual
- 251 * Machine Specification, Second Edition</em>, tables 4.1, 4.4,
- 252 * 4.5, and 4.7.
- 253 */
- 254
- 255 /**
- 256 * The <code>int</code> value representing the <code>public</code>
- 257 * modifier.
- 258 */
- 259 public static final int PUBLIC = 0x00000001;
- 260
- 261 /**
- 262 * The <code>int</code> value representing the <code>private</code>
- 263 * modifier.
- 264 */
- 265 public static final int PRIVATE = 0x00000002;
- 266
- 267 /**
- 268 * The <code>int</code> value representing the <code>protected</code>
- 269 * modifier.
- 270 */
- 271 public static final int PROTECTED = 0x00000004;
- 272
- 273 /**
- 274 * The <code>int</code> value representing the <code>static</code>
- 275 * modifier.
- 276 */
- 277 public static final int STATIC = 0x00000008;
- 278
- 279 /**
- 280 * The <code>int</code> value representing the <code>final</code>
- 281 * modifier.
- 282 */
- 283 public static final int FINAL = 0x00000010;
- 284
- 285 /**
- 286 * The <code>int</code> value representing the <code>synchronized</code>
- 287 * modifier.
- 288 */
- 289 public static final int SYNCHRONIZED = 0x00000020;
- 290
- 291 /**
- 292 * The <code>int</code> value representing the <code>volatile</code>
- 293 * modifier.
- 294 */
- 295 public static final int VOLATILE = 0x00000040;
- 296
- 297 /**
- 298 * The <code>int</code> value representing the <code>transient</code>
- 299 * modifier.
- 300 */
- 301 public static final int TRANSIENT = 0x00000080;
- 302
- 303 /**
- 304 * The <code>int</code> value representing the <code>native</code>
- 305 * modifier.
- 306 */
- 307 public static final int NATIVE = 0x00000100;
- 308
- 309 /**
- 310 * The <code>int</code> value representing the <code>interface</code>
- 311 * modifier.
- 312 */
- 313 public static final int INTERFACE = 0x00000200;
- 314
- 315 /**
- 316 * The <code>int</code> value representing the <code>abstract</code>
- 317 * modifier.
- 318 */
- 319 public static final int ABSTRACT = 0x00000400;
- 320
- 321 /**
- 322 * The <code>int</code> value representing the <code>strictfp</code>
- 323 * modifier.
- 324 */
- 325 public static final int STRICT = 0x00000800;
- 326
- 327 // Bits not (yet) exposed in the public API either because they
- 328 // have different meanings for fields and methods and there is no
- 329 // way to distinguish between the two in this class, or because
- 330 // they are not Java programming language keywords
- 331 static final int BRIDGE = 0x00000040;
- 332 static final int VARARGS = 0x00000080;
- 333 static final int SYNTHETIC = 0x00001000;
- 334 static final int ANNOTATION= 0x00002000;
- 335 static final int ENUM = 0x00004000;
- 336 static boolean isSynthetic(int mod) {
- 337 return (mod & SYNTHETIC) != 0;
- 338 }
- 339}
