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| 1 | /* | ||
| 2 | * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved. | ||
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | ||
| 4 | * | ||
| 5 | * This code is free software; you can redistribute it and/or modify it | ||
| 6 | * under the terms of the GNU General Public License version 2 only, as | ||
| 7 | * published by the Free Software Foundation. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | package sun.reflect; | ||
| 27 | |||
| 28 | import java.lang.reflect.Field; | ||
| 29 | import java.lang.reflect.Method; | ||
| 30 | import java.lang.reflect.Constructor; | ||
| 31 | import java.lang.reflect.Modifier; | ||
| 32 | import java.security.AccessController; | ||
| 33 | import java.security.Permission; | ||
| 34 | import java.security.PrivilegedAction; | ||
| 35 | |||
| 36 | /** <P> The master factory for all reflective objects, both those in | ||
| 37 | java.lang.reflect (Fields, Methods, Constructors) as well as their | ||
| 38 | delegates (FieldAccessors, MethodAccessors, ConstructorAccessors). | ||
| 39 | </P> | ||
| 40 | |||
| 41 | <P> The methods in this class are extremely unsafe and can cause | ||
| 42 | subversion of both the language and the verifier. For this reason, | ||
| 43 | they are all instance methods, and access to the constructor of | ||
| 44 | this factory is guarded by a security check, in similar style to | ||
| 45 | {@link sun.misc.Unsafe}. </P> | ||
| 46 | */ | ||
| 47 | |||
| 48 | public class ReflectionFactory { | ||
| 49 | |||
| 50 | private static boolean initted = false; | ||
| 51 | private static Permission reflectionFactoryAccessPerm | ||
| 52 | = new RuntimePermission("reflectionFactoryAccess"); | ||
| 53 | private static ReflectionFactory soleInstance = new ReflectionFactory(); | ||
| 54 | // Provides access to package-private mechanisms in java.lang.reflect | ||
| 55 | private static volatile LangReflectAccess langReflectAccess; | ||
| 56 | |||
| 57 | // | ||
| 58 | // "Inflation" mechanism. Loading bytecodes to implement | ||
| 59 | // Method.invoke() and Constructor.newInstance() currently costs | ||
| 60 | // 3-4x more than an invocation via native code for the first | ||
| 61 | // invocation (though subsequent invocations have been benchmarked | ||
| 62 | // to be over 20x faster). Unfortunately this cost increases | ||
| 63 | // startup time for certain applications that use reflection | ||
| 64 | // intensively (but only once per class) to bootstrap themselves. | ||
| 65 | // To avoid this penalty we reuse the existing JVM entry points | ||
| 66 | // for the first few invocations of Methods and Constructors and | ||
| 67 | // then switch to the bytecode-based implementations. | ||
| 68 | // | ||
| 69 | // Package-private to be accessible to NativeMethodAccessorImpl | ||
| 70 | // and NativeConstructorAccessorImpl | ||
| 71 | private static boolean noInflation = false; | ||
| 72 | private static int inflationThreshold = 15; | ||
| 73 | |||
| 74 | private ReflectionFactory() { | ||
| 75 | } | ||
| 76 | |||
| 77 | /** | ||
| 78 | * A convenience class for acquiring the capability to instantiate | ||
| 79 | * reflective objects. Use this instead of a raw call to {@link | ||
| 80 | * #getReflectionFactory} in order to avoid being limited by the | ||
| 81 | * permissions of your callers. | ||
| 82 | * | ||
| 83 | * <p>An instance of this class can be used as the argument of | ||
| 84 | * <code>AccessController.doPrivileged</code>. | ||
| 85 | */ | ||
| 86 | public static final class GetReflectionFactoryAction | ||
| 87 | implements PrivilegedAction<ReflectionFactory> { | ||
| 88 | public ReflectionFactory run() { | ||
| 89 | return getReflectionFactory(); | ||
| 90 | } | ||
| 91 | } | ||
| 92 | |||
| 93 | /** | ||
| 94 | * Provides the caller with the capability to instantiate reflective | ||
| 95 | * objects. | ||
| 96 | * | ||
| 97 | * <p> First, if there is a security manager, its | ||
| 98 | * <code>checkPermission</code> method is called with a {@link | ||
| 99 | * java.lang.RuntimePermission} with target | ||
| 100 | * <code>"reflectionFactoryAccess"</code>. This may result in a | ||
| 101 | * security exception. | ||
| 102 | * | ||
| 103 | * <p> The returned <code>ReflectionFactory</code> object should be | ||
| 104 | * carefully guarded by the caller, since it can be used to read and | ||
| 105 | * write private data and invoke private methods, as well as to load | ||
| 106 | * unverified bytecodes. It must never be passed to untrusted code. | ||
| 107 | * | ||
| 108 | * @exception SecurityException if a security manager exists and its | ||
| 109 | * <code>checkPermission</code> method doesn't allow | ||
| 110 | * access to the RuntimePermission "reflectionFactoryAccess". */ | ||
| 111 | public static ReflectionFactory getReflectionFactory() { | ||
| 112 | SecurityManager security = System.getSecurityManager(); | ||
| 113 | if (security != null) { | ||
| 114 | // TO DO: security.checkReflectionFactoryAccess(); | ||
| 115 | security.checkPermission(reflectionFactoryAccessPerm); | ||
| 116 | } | ||
| 117 | return soleInstance; | ||
| 118 | } | ||
| 119 | |||
| 120 | //-------------------------------------------------------------------------- | ||
| 121 | // | ||
| 122 | // Routines used by java.lang.reflect | ||
| 123 | // | ||
| 124 | // | ||
| 125 | |||
| 126 | /** Called only by java.lang.reflect.Modifier's static initializer */ | ||
| 127 | public void setLangReflectAccess(LangReflectAccess access) { | ||
| 128 | langReflectAccess = access; | ||
| 129 | } | ||
| 130 | |||
| 131 | /** | ||
| 132 | * Note: this routine can cause the declaring class for the field | ||
| 133 | * be initialized and therefore must not be called until the | ||
| 134 | * first get/set of this field. | ||
| 135 | * @param field the field | ||
| 136 | * @param override true if caller has overridden aaccessibility | ||
| 137 | */ | ||
| 138 | public FieldAccessor newFieldAccessor(Field field, boolean override) { | ||
| 139 | checkInitted(); | ||
| 140 | return UnsafeFieldAccessorFactory.newFieldAccessor(field, override); | ||
| 141 | } | ||
| 142 | |||
| 143 | public MethodAccessor newMethodAccessor(Method method) { | ||
| 144 | checkInitted(); | ||
| 145 | |||
| 146 | if (noInflation) { | ||
| 147 | return new MethodAccessorGenerator(). | ||
| 148 | generateMethod(method.getDeclaringClass(), | ||
| 149 | method.getName(), | ||
| 150 | method.getParameterTypes(), | ||
| 151 | method.getReturnType(), | ||
| 152 | method.getExceptionTypes(), | ||
| 153 | method.getModifiers()); | ||
| 154 | } else { | ||
| 155 | NativeMethodAccessorImpl acc = | ||
| 156 | new NativeMethodAccessorImpl(method); | ||
| 157 | DelegatingMethodAccessorImpl res = | ||
| 158 | new DelegatingMethodAccessorImpl(acc); | ||
| 159 | acc.setParent(res); | ||
| 160 | return res; | ||
| 161 | } | ||
| 162 | } | ||
| 163 | |||
| 164 | public ConstructorAccessor newConstructorAccessor(Constructor c) { | ||
| 165 | checkInitted(); | ||
| 166 | |||
| 167 | Class<?> declaringClass = c.getDeclaringClass(); | ||
| 168 | if (Modifier.isAbstract(declaringClass.getModifiers())) { | ||
| 169 | return new InstantiationExceptionConstructorAccessorImpl(null); | ||
| 170 | } | ||
| 171 | if (declaringClass == Class.class) { | ||
| 172 | return new InstantiationExceptionConstructorAccessorImpl | ||
| 173 | ("Can not instantiate java.lang.Class"); | ||
| 174 | } | ||
| 175 | // Bootstrapping issue: since we use Class.newInstance() in | ||
| 176 | // the ConstructorAccessor generation process, we have to | ||
| 177 | // break the cycle here. | ||
| 178 | if (Reflection.isSubclassOf(declaringClass, | ||
| 179 | ConstructorAccessorImpl.class)) { | ||
| 180 | return new BootstrapConstructorAccessorImpl(c); | ||
| 181 | } | ||
| 182 | |||
| 183 | if (noInflation) { | ||
| 184 | return new MethodAccessorGenerator(). | ||
| 185 | generateConstructor(c.getDeclaringClass(), | ||
| 186 | c.getParameterTypes(), | ||
| 187 | c.getExceptionTypes(), | ||
| 188 | c.getModifiers()); | ||
| 189 | } else { | ||
| 190 | NativeConstructorAccessorImpl acc = | ||
| 191 | new NativeConstructorAccessorImpl(c); | ||
| 192 | DelegatingConstructorAccessorImpl res = | ||
| 193 | new DelegatingConstructorAccessorImpl(acc); | ||
| 194 | acc.setParent(res); | ||
| 195 | return res; | ||
| 196 | } | ||
| 197 | } | ||
| 198 | |||
| 199 | //-------------------------------------------------------------------------- | ||
| 200 | // | ||
| 201 | // Routines used by java.lang | ||
| 202 | // | ||
| 203 | // | ||
| 204 | |||
| 205 | /** Creates a new java.lang.reflect.Field. Access checks as per | ||
| 206 | java.lang.reflect.AccessibleObject are not overridden. */ | ||
| 207 | public Field newField(Class<?> declaringClass, | ||
| 208 | String name, | ||
| 209 | Class<?> type, | ||
| 210 | int modifiers, | ||
| 211 | int slot, | ||
| 212 | String signature, | ||
| 213 | byte[] annotations) | ||
| 214 | { | ||
| 215 | return langReflectAccess().newField(declaringClass, | ||
| 216 | name, | ||
| 217 | type, | ||
| 218 | modifiers, | ||
| 219 | slot, | ||
| 220 | signature, | ||
| 221 | annotations); | ||
| 222 | } | ||
| 223 | |||
| 224 | /** Creates a new java.lang.reflect.Method. Access checks as per | ||
| 225 | java.lang.reflect.AccessibleObject are not overridden. */ | ||
| 226 | public Method newMethod(Class<?> declaringClass, | ||
| 227 | String name, | ||
| 228 | Class<?>[] parameterTypes, | ||
| 229 | Class<?> returnType, | ||
| 230 | Class<?>[] checkedExceptions, | ||
| 231 | int modifiers, | ||
| 232 | int slot, | ||
| 233 | String signature, | ||
| 234 | byte[] annotations, | ||
| 235 | byte[] parameterAnnotations, | ||
| 236 | byte[] annotationDefault) | ||
| 237 | { | ||
| 238 | return langReflectAccess().newMethod(declaringClass, | ||
| 239 | name, | ||
| 240 | parameterTypes, | ||
| 241 | returnType, | ||
| 242 | checkedExceptions, | ||
| 243 | modifiers, | ||
| 244 | slot, | ||
| 245 | signature, | ||
| 246 | annotations, | ||
| 247 | parameterAnnotations, | ||
| 248 | annotationDefault); | ||
| 249 | } | ||
| 250 | |||
| 251 | /** Creates a new java.lang.reflect.Constructor. Access checks as | ||
| 252 | per java.lang.reflect.AccessibleObject are not overridden. */ | ||
| 253 | public Constructor newConstructor(Class<?> declaringClass, | ||
| 254 | Class<?>[] parameterTypes, | ||
| 255 | Class<?>[] checkedExceptions, | ||
| 256 | int modifiers, | ||
| 257 | int slot, | ||
| 258 | String signature, | ||
| 259 | byte[] annotations, | ||
| 260 | byte[] parameterAnnotations) | ||
| 261 | { | ||
| 262 | return langReflectAccess().newConstructor(declaringClass, | ||
| 263 | parameterTypes, | ||
| 264 | checkedExceptions, | ||
| 265 | modifiers, | ||
| 266 | slot, | ||
| 267 | signature, | ||
| 268 | annotations, | ||
| 269 | parameterAnnotations); | ||
| 270 | } | ||
| 271 | |||
| 272 | /** Gets the MethodAccessor object for a java.lang.reflect.Method */ | ||
| 273 | public MethodAccessor getMethodAccessor(Method m) { | ||
| 274 | return langReflectAccess().getMethodAccessor(m); | ||
| 275 | } | ||
| 276 | |||
| 277 | /** Sets the MethodAccessor object for a java.lang.reflect.Method */ | ||
| 278 | public void setMethodAccessor(Method m, MethodAccessor accessor) { | ||
| 279 | langReflectAccess().setMethodAccessor(m, accessor); | ||
| 280 | } | ||
| 281 | |||
| 282 | /** Gets the ConstructorAccessor object for a | ||
| 283 | java.lang.reflect.Constructor */ | ||
| 284 | public ConstructorAccessor getConstructorAccessor(Constructor c) { | ||
| 285 | return langReflectAccess().getConstructorAccessor(c); | ||
| 286 | } | ||
| 287 | |||
| 288 | /** Sets the ConstructorAccessor object for a | ||
| 289 | java.lang.reflect.Constructor */ | ||
| 290 | public void setConstructorAccessor(Constructor c, | ||
| 291 | ConstructorAccessor accessor) | ||
| 292 | { | ||
| 293 | langReflectAccess().setConstructorAccessor(c, accessor); | ||
| 294 | } | ||
| 295 | |||
| 296 | /** Makes a copy of the passed method. The returned method is a | ||
| 297 | "child" of the passed one; see the comments in Method.java for | ||
| 298 | details. */ | ||
| 299 | public Method copyMethod(Method arg) { | ||
| 300 | return langReflectAccess().copyMethod(arg); | ||
| 301 | } | ||
| 302 | |||
| 303 | /** Makes a copy of the passed field. The returned field is a | ||
| 304 | "child" of the passed one; see the comments in Field.java for | ||
| 305 | details. */ | ||
| 306 | public Field copyField(Field arg) { | ||
| 307 | return langReflectAccess().copyField(arg); | ||
| 308 | } | ||
| 309 | |||
| 310 | /** Makes a copy of the passed constructor. The returned | ||
| 311 | constructor is a "child" of the passed one; see the comments | ||
| 312 | in Constructor.java for details. */ | ||
| 313 | public <T> Constructor<T> copyConstructor(Constructor<T> arg) { | ||
| 314 | return langReflectAccess().copyConstructor(arg); | ||
| 315 | } | ||
| 316 | |||
| 317 | //-------------------------------------------------------------------------- | ||
| 318 | // | ||
| 319 | // Routines used by serialization | ||
| 320 | // | ||
| 321 | // | ||
| 322 | |||
| 323 | public Constructor newConstructorForSerialization | ||
| 324 | (Class<?> classToInstantiate, Constructor constructorToCall) | ||
| 325 | { | ||
| 326 | // Fast path | ||
| 327 | if (constructorToCall.getDeclaringClass() == classToInstantiate) { | ||
| 328 | return constructorToCall; | ||
| 329 | } | ||
| 330 | |||
| 331 | ConstructorAccessor acc = new MethodAccessorGenerator(). | ||
| 332 | generateSerializationConstructor(classToInstantiate, | ||
| 333 | constructorToCall.getParameterTypes(), | ||
| 334 | constructorToCall.getExceptionTypes(), | ||
| 335 | constructorToCall.getModifiers(), | ||
| 336 | constructorToCall.getDeclaringClass()); | ||
| 337 | Constructor c = newConstructor(constructorToCall.getDeclaringClass(), | ||
| 338 | constructorToCall.getParameterTypes(), | ||
| 339 | constructorToCall.getExceptionTypes(), | ||
| 340 | constructorToCall.getModifiers(), | ||
| 341 | langReflectAccess(). | ||
| 342 | getConstructorSlot(constructorToCall), | ||
| 343 | langReflectAccess(). | ||
| 344 | getConstructorSignature(constructorToCall), | ||
| 345 | langReflectAccess(). | ||
| 346 | getConstructorAnnotations(constructorToCall), | ||
| 347 | langReflectAccess(). | ||
| 348 | getConstructorParameterAnnotations(constructorToCall)); | ||
| 349 | setConstructorAccessor(c, acc); | ||
| 350 | return c; | ||
| 351 | } | ||
| 352 | |||
| 353 | //-------------------------------------------------------------------------- | ||
| 354 | // | ||
| 355 | // Internals only below this point | ||
| 356 | // | ||
| 357 | |||
| 358 | static int inflationThreshold() { | ||
| 359 | return inflationThreshold; | ||
| 360 | } | ||
| 361 | |||
| 362 | /** We have to defer full initialization of this class until after | ||
| 363 | the static initializer is run since java.lang.reflect.Method's | ||
| 364 | static initializer (more properly, that for | ||
| 365 | java.lang.reflect.AccessibleObject) causes this class's to be | ||
| 366 | run, before the system properties are set up. */ | ||
| 367 | private static void checkInitted() { | ||
| 368 | if (initted) return; | ||
| 369 | AccessController.doPrivileged( | ||
| 370 | new PrivilegedAction<Void>() { | ||
| 371 | public Void run() { | ||
| 372 | // Tests to ensure the system properties table is fully | ||
| 373 | // initialized. This is needed because reflection code is | ||
| 374 | // called very early in the initialization process (before | ||
| 375 | // command-line arguments have been parsed and therefore | ||
| 376 | // these user-settable properties installed.) We assume that | ||
| 377 | // if System.out is non-null then the System class has been | ||
| 378 | // fully initialized and that the bulk of the startup code | ||
| 379 | // has been run. | ||
| 380 | |||
| 381 | if (System.out == null) { | ||
| 382 | // java.lang.System not yet fully initialized | ||
| 383 | return null; | ||
| 384 | } | ||
| 385 | |||
| 386 | String val = System.getProperty("sun.reflect.noInflation"); | ||
| 387 | if (val != null && val.equals("true")) { | ||
| 388 | noInflation = true; | ||
| 389 | } | ||
| 390 | |||
| 391 | val = System.getProperty("sun.reflect.inflationThreshold"); | ||
| 392 | if (val != null) { | ||
| 393 | try { | ||
| 394 | inflationThreshold = Integer.parseInt(val); | ||
| 395 | } catch (NumberFormatException e) { | ||
| 396 | throw (RuntimeException) | ||
| 397 | new RuntimeException("Unable to parse property sun.reflect.inflationThreshold"). | ||
| 398 | initCause(e); | ||
| 399 | } | ||
| 400 | } | ||
| 401 | |||
| 402 | initted = true; | ||
| 403 | return null; | ||
| 404 | } | ||
| 405 | }); | ||
| 406 | } | ||
| 407 | |||
| 408 | private static LangReflectAccess langReflectAccess() { | ||
| 409 | if (langReflectAccess == null) { | ||
| 410 | // Call a static method to get class java.lang.reflect.Modifier | ||
| 411 | // initialized. Its static initializer will cause | ||
| 412 | // setLangReflectAccess() to be called from the context of the | ||
| 413 | // java.lang.reflect package. | ||
| 414 | Modifier.isPublic(Modifier.PUBLIC); | ||
| 415 | } | ||
| 416 | return langReflectAccess; | ||
| 417 | } | ||
| 418 | } | ||