1 /* 2 * Copyright (c) 1994, 2022, 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 java.lang; 27 28 import java.lang.annotation.Annotation; 29 import java.lang.constant.ClassDesc; 30 import java.lang.invoke.TypeDescriptor; 31 import java.lang.invoke.MethodHandles; 32 import java.lang.module.ModuleReader; 33 import java.lang.ref.SoftReference; 34 import java.io.IOException; 35 import java.io.InputStream; 36 import java.io.ObjectStreamField; 37 import java.lang.reflect.AnnotatedElement; 38 import java.lang.reflect.AnnotatedType; 39 import java.lang.reflect.Array; 40 import java.lang.reflect.Constructor; 41 import java.lang.reflect.Executable; 42 import java.lang.reflect.Field; 43 import java.lang.reflect.GenericArrayType; 44 import java.lang.reflect.GenericDeclaration; 45 import java.lang.reflect.InvocationTargetException; 46 import java.lang.reflect.Member; 47 import java.lang.reflect.Method; 48 import java.lang.reflect.Modifier; 49 import java.lang.reflect.Proxy; 50 import java.lang.reflect.RecordComponent; 51 import java.lang.reflect.Type; 52 import java.lang.reflect.TypeVariable; 53 import java.lang.constant.Constable; 54 import java.net.URL; 55 import java.security.AccessController; 56 import java.security.PrivilegedAction; 57 import java.util.ArrayList; 58 import java.util.Arrays; 59 import java.util.Collection; 60 import java.util.HashMap; 61 import java.util.HashSet; 62 import java.util.LinkedHashMap; 63 import java.util.LinkedHashSet; 64 import java.util.List; 65 import java.util.Map; 66 import java.util.Objects; 67 import java.util.Optional; 68 import java.util.Set; 69 import java.util.stream.Collectors; 70 71 import jdk.internal.loader.BootLoader; 72 import jdk.internal.loader.BuiltinClassLoader; 73 import jdk.internal.misc.Unsafe; 74 import jdk.internal.module.Resources; 75 import jdk.internal.reflect.CallerSensitive; 76 import jdk.internal.reflect.CallerSensitiveAdapter; 77 import jdk.internal.reflect.ConstantPool; 78 import jdk.internal.reflect.Reflection; 79 import jdk.internal.reflect.ReflectionFactory; 80 import jdk.internal.vm.annotation.ForceInline; 81 import jdk.internal.vm.annotation.IntrinsicCandidate; 82 import sun.invoke.util.Wrapper; 83 import sun.reflect.generics.factory.CoreReflectionFactory; 84 import sun.reflect.generics.factory.GenericsFactory; 85 import sun.reflect.generics.repository.ClassRepository; 86 import sun.reflect.generics.repository.MethodRepository; 87 import sun.reflect.generics.repository.ConstructorRepository; 88 import sun.reflect.generics.scope.ClassScope; 89 import sun.security.util.SecurityConstants; 90 import sun.reflect.annotation.*; 91 import sun.reflect.misc.ReflectUtil; 92 93 /** 94 * Instances of the class {@code Class} represent classes and 95 * interfaces in a running Java application. An enum class and a record 96 * class are kinds of class; an annotation interface is a kind of 97 * interface. Every array also belongs to a class that is reflected as 98 * a {@code Class} object that is shared by all arrays with the same 99 * element type and number of dimensions. The primitive Java types 100 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code 101 * int}, {@code long}, {@code float}, and {@code double}), and the 102 * keyword {@code void} are also represented as {@code Class} objects. 103 * 104 * <p> {@code Class} has no public constructor. Instead a {@code Class} 105 * object is constructed automatically by the Java Virtual Machine when 106 * a class is derived from the bytes of a {@code class} file through 107 * the invocation of one of the following methods: 108 * <ul> 109 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass} 110 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[]) 111 * java.lang.invoke.MethodHandles.Lookup::defineClass} 112 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 113 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass} 114 * </ul> 115 * 116 * <p> The methods of class {@code Class} expose many characteristics of a 117 * class or interface. Most characteristics are derived from the {@code class} 118 * file that the class loader passed to the Java Virtual Machine or 119 * from the {@code class} file passed to {@code Lookup::defineClass} 120 * or {@code Lookup::defineHiddenClass}. 121 * A few characteristics are determined by the class loading environment 122 * at run time, such as the module returned by {@link #getModule() getModule()}. 123 * 124 * <p> The following example uses a {@code Class} object to print the 125 * class name of an object: 126 * 127 * <blockquote><pre> 128 * void printClassName(Object obj) { 129 * System.out.println("The class of " + obj + 130 * " is " + obj.getClass().getName()); 131 * } 132 * </pre></blockquote> 133 * 134 * It is also possible to get the {@code Class} object for a named 135 * class or interface (or for {@code void}) using a <i>class literal</i>. 136 * For example: 137 * 138 * <blockquote> 139 * {@code System.out.println("The name of class Foo is: "+Foo.class.getName());} 140 * </blockquote> 141 * 142 * <p> Some methods of class {@code Class} expose whether the declaration of 143 * a class or interface in Java source code was <em>enclosed</em> within 144 * another declaration. Other methods describe how a class or interface 145 * is situated in a <em>nest</em>. A <a id="nest">nest</a> is a set of 146 * classes and interfaces, in the same run-time package, that 147 * allow mutual access to their {@code private} members. 148 * The classes and interfaces are known as <em>nestmates</em>. 149 * One nestmate acts as the 150 * <em>nest host</em>, and enumerates the other nestmates which 151 * belong to the nest; each of them in turn records it as the nest host. 152 * The classes and interfaces which belong to a nest, including its host, are 153 * determined when 154 * {@code class} files are generated, for example, a Java compiler 155 * will typically record a top-level class as the host of a nest where the 156 * other members are the classes and interfaces whose declarations are 157 * enclosed within the top-level class declaration. 158 * 159 * <p> A class or interface created by the invocation of 160 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 161 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <em>hidden</em>} 162 * class or interface. 163 * All kinds of class, including enum classes and record classes, may be 164 * hidden classes; all kinds of interface, including annotation interfaces, 165 * may be hidden interfaces. 166 * 167 * The {@linkplain #getName() name of a hidden class or interface} is 168 * not a <a href="ClassLoader.html#binary-name">binary name</a>, 169 * which means the following: 170 * <ul> 171 * <li>A hidden class or interface cannot be referenced by the constant pools 172 * of other classes and interfaces. 173 * <li>A hidden class or interface cannot be described in 174 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by 175 * {@link #describeConstable() Class::describeConstable}, 176 * {@link ClassDesc#of(String) ClassDesc::of}, or 177 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}. 178 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName} 179 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}. 180 * </ul> 181 * 182 * A hidden class or interface is never an array class, but may be 183 * the element type of an array. In all other respects, the fact that 184 * a class or interface is hidden has no bearing on the characteristics 185 * exposed by the methods of class {@code Class}. 186 * 187 * @param <T> the type of the class modeled by this {@code Class} 188 * object. For example, the type of {@code String.class} is {@code 189 * Class<String>}. Use {@code Class<?>} if the class being modeled is 190 * unknown. 191 * 192 * @see java.lang.ClassLoader#defineClass(byte[], int, int) 193 * @since 1.0 194 * @jls 15.8.2 Class Literals 195 */ 196 public final class Class<T> implements java.io.Serializable, 197 GenericDeclaration, 198 Type, 199 AnnotatedElement, 200 TypeDescriptor.OfField<Class<?>>, 201 Constable { 202 private static final int ANNOTATION= 0x00002000; 203 private static final int ENUM = 0x00004000; 204 private static final int SYNTHETIC = 0x00001000; 205 206 private static native void registerNatives(); 207 static { 208 registerNatives(); 209 } 210 211 /* 212 * Private constructor. Only the Java Virtual Machine creates Class objects. 213 * This constructor is not used and prevents the default constructor being 214 * generated. 215 */ 216 private Class(ClassLoader loader, Class<?> arrayComponentType) { 217 // Initialize final field for classLoader. The initialization value of non-null 218 // prevents future JIT optimizations from assuming this final field is null. 219 classLoader = loader; 220 componentType = arrayComponentType; 221 } 222 223 /** 224 * Converts the object to a string. The string representation is the 225 * string "class" or "interface", followed by a space, and then by the 226 * name of the class in the format returned by {@code getName}. 227 * If this {@code Class} object represents a primitive type, 228 * this method returns the name of the primitive type. If 229 * this {@code Class} object represents void this method returns 230 * "void". If this {@code Class} object represents an array type, 231 * this method returns "class " followed by {@code getName}. 232 * 233 * @return a string representation of this {@code Class} object. 234 */ 235 public String toString() { 236 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class "; 237 return kind.concat(getName()); 238 } 239 240 /** 241 * Returns a string describing this {@code Class}, including 242 * information about modifiers and type parameters. 243 * 244 * The string is formatted as a list of type modifiers, if any, 245 * followed by the kind of type (empty string for primitive types 246 * and {@code class}, {@code enum}, {@code interface}, 247 * {@code @interface}, or {@code record} as appropriate), followed 248 * by the type's name, followed by an angle-bracketed 249 * comma-separated list of the type's type parameters, if any, 250 * including informative bounds on the type parameters, if any. 251 * 252 * A space is used to separate modifiers from one another and to 253 * separate any modifiers from the kind of type. The modifiers 254 * occur in canonical order. If there are no type parameters, the 255 * type parameter list is elided. 256 * 257 * For an array type, the string starts with the type name, 258 * followed by an angle-bracketed comma-separated list of the 259 * type's type parameters, if any, followed by a sequence of 260 * {@code []} characters, one set of brackets per dimension of 261 * the array. 262 * 263 * <p>Note that since information about the runtime representation 264 * of a type is being generated, modifiers not present on the 265 * originating source code or illegal on the originating source 266 * code may be present. 267 * 268 * @return a string describing this {@code Class}, including 269 * information about modifiers and type parameters 270 * 271 * @since 1.8 272 */ 273 public String toGenericString() { 274 if (isPrimitive()) { 275 return toString(); 276 } else { 277 StringBuilder sb = new StringBuilder(); 278 Class<?> component = this; 279 int arrayDepth = 0; 280 281 if (isArray()) { 282 do { 283 arrayDepth++; 284 component = component.getComponentType(); 285 } while (component.isArray()); 286 sb.append(component.getName()); 287 } else { 288 // Class modifiers are a superset of interface modifiers 289 int modifiers = getModifiers() & Modifier.classModifiers(); 290 if (modifiers != 0) { 291 sb.append(Modifier.toString(modifiers)); 292 sb.append(' '); 293 } 294 295 if (isAnnotation()) { 296 sb.append('@'); 297 } 298 if (isInterface()) { // Note: all annotation interfaces are interfaces 299 sb.append("interface"); 300 } else { 301 if (isEnum()) 302 sb.append("enum"); 303 else if (isRecord()) 304 sb.append("record"); 305 else 306 sb.append("class"); 307 } 308 sb.append(' '); 309 sb.append(getName()); 310 } 311 312 TypeVariable<?>[] typeparms = component.getTypeParameters(); 313 if (typeparms.length > 0) { 314 sb.append(Arrays.stream(typeparms) 315 .map(Class::typeVarBounds) 316 .collect(Collectors.joining(",", "<", ">"))); 317 } 318 319 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth)); 320 321 return sb.toString(); 322 } 323 } 324 325 static String typeVarBounds(TypeVariable<?> typeVar) { 326 Type[] bounds = typeVar.getBounds(); 327 if (bounds.length == 1 && bounds[0].equals(Object.class)) { 328 return typeVar.getName(); 329 } else { 330 return typeVar.getName() + " extends " + 331 Arrays.stream(bounds) 332 .map(Type::getTypeName) 333 .collect(Collectors.joining(" & ")); 334 } 335 } 336 337 /** 338 * Returns the {@code Class} object associated with the class or 339 * interface with the given string name. Invoking this method is 340 * equivalent to: 341 * 342 * <blockquote> 343 * {@code Class.forName(className, true, currentLoader)} 344 * </blockquote> 345 * 346 * where {@code currentLoader} denotes the defining class loader of 347 * the current class. 348 * 349 * <p> For example, the following code fragment returns the 350 * runtime {@code Class} descriptor for the class named 351 * {@code java.lang.Thread}: 352 * 353 * <blockquote> 354 * {@code Class t = Class.forName("java.lang.Thread")} 355 * </blockquote> 356 * <p> 357 * A call to {@code forName("X")} causes the class named 358 * {@code X} to be initialized. 359 * 360 * @param className the fully qualified name of the desired class. 361 * @return the {@code Class} object for the class with the 362 * specified name. 363 * @throws LinkageError if the linkage fails 364 * @throws ExceptionInInitializerError if the initialization provoked 365 * by this method fails 366 * @throws ClassNotFoundException if the class cannot be located 367 * 368 * @jls 12.2 Loading of Classes and Interfaces 369 * @jls 12.3 Linking of Classes and Interfaces 370 * @jls 12.4 Initialization of Classes and Interfaces 371 */ 372 @CallerSensitive 373 public static Class<?> forName(String className) 374 throws ClassNotFoundException { 375 Class<?> caller = Reflection.getCallerClass(); 376 return forName(className, caller); 377 } 378 379 // Caller-sensitive adapter method for reflective invocation 380 @CallerSensitiveAdapter 381 private static Class<?> forName(String className, Class<?> caller) 382 throws ClassNotFoundException { 383 return forName0(className, true, ClassLoader.getClassLoader(caller), caller); 384 } 385 386 /** 387 * Returns the {@code Class} object associated with the class or 388 * interface with the given string name, using the given class loader. 389 * Given the fully qualified name for a class or interface (in the same 390 * format returned by {@code getName}) this method attempts to 391 * locate and load the class or interface. The specified class 392 * loader is used to load the class or interface. If the parameter 393 * {@code loader} is null, the class is loaded through the bootstrap 394 * class loader. The class is initialized only if the 395 * {@code initialize} parameter is {@code true} and if it has 396 * not been initialized earlier. 397 * 398 * <p> If {@code name} denotes a primitive type or void, an attempt 399 * will be made to locate a user-defined class in the unnamed package whose 400 * name is {@code name}. Therefore, this method cannot be used to 401 * obtain any of the {@code Class} objects representing primitive 402 * types or void. 403 * 404 * <p> If {@code name} denotes an array class, the component type of 405 * the array class is loaded but not initialized. 406 * 407 * <p> For example, in an instance method the expression: 408 * 409 * <blockquote> 410 * {@code Class.forName("Foo")} 411 * </blockquote> 412 * 413 * is equivalent to: 414 * 415 * <blockquote> 416 * {@code Class.forName("Foo", true, this.getClass().getClassLoader())} 417 * </blockquote> 418 * 419 * Note that this method throws errors related to loading, linking 420 * or initializing as specified in Sections {@jls 12.2}, {@jls 421 * 12.3}, and {@jls 12.4} of <cite>The Java Language 422 * Specification</cite>. 423 * Note that this method does not check whether the requested class 424 * is accessible to its caller. 425 * 426 * @param name fully qualified name of the desired class 427 428 * @param initialize if {@code true} the class will be initialized 429 * (which implies linking). See Section {@jls 430 * 12.4} of <cite>The Java Language 431 * Specification</cite>. 432 * @param loader class loader from which the class must be loaded 433 * @return class object representing the desired class 434 * 435 * @throws LinkageError if the linkage fails 436 * @throws ExceptionInInitializerError if the initialization provoked 437 * by this method fails 438 * @throws ClassNotFoundException if the class cannot be located by 439 * the specified class loader 440 * @throws SecurityException 441 * if a security manager is present, and the {@code loader} is 442 * {@code null}, and the caller's class loader is not 443 * {@code null}, and the caller does not have the 444 * {@link RuntimePermission}{@code ("getClassLoader")} 445 * 446 * @see java.lang.Class#forName(String) 447 * @see java.lang.ClassLoader 448 * 449 * @jls 12.2 Loading of Classes and Interfaces 450 * @jls 12.3 Linking of Classes and Interfaces 451 * @jls 12.4 Initialization of Classes and Interfaces 452 * @since 1.2 453 */ 454 @CallerSensitive 455 public static Class<?> forName(String name, boolean initialize, 456 ClassLoader loader) 457 throws ClassNotFoundException 458 { 459 Class<?> caller = null; 460 @SuppressWarnings("removal") 461 SecurityManager sm = System.getSecurityManager(); 462 if (sm != null) { 463 // Reflective call to get caller class is only needed if a security manager 464 // is present. Avoid the overhead of making this call otherwise. 465 caller = Reflection.getCallerClass(); 466 } 467 return forName(name, initialize, loader, caller); 468 } 469 470 // Caller-sensitive adapter method for reflective invocation 471 @CallerSensitiveAdapter 472 private static Class<?> forName(String name, boolean initialize, ClassLoader loader, Class<?> caller) 473 throws ClassNotFoundException 474 { 475 @SuppressWarnings("removal") 476 SecurityManager sm = System.getSecurityManager(); 477 if (sm != null) { 478 // Reflective call to get caller class is only needed if a security manager 479 // is present. Avoid the overhead of making this call otherwise. 480 if (loader == null) { 481 ClassLoader ccl = ClassLoader.getClassLoader(caller); 482 if (ccl != null) { 483 sm.checkPermission( 484 SecurityConstants.GET_CLASSLOADER_PERMISSION); 485 } 486 } 487 } 488 return forName0(name, initialize, loader, caller); 489 } 490 491 /** Called after security check for system loader access checks have been made. */ 492 private static native Class<?> forName0(String name, boolean initialize, 493 ClassLoader loader, 494 Class<?> caller) 495 throws ClassNotFoundException; 496 497 498 /** 499 * Returns the {@code Class} with the given <a href="ClassLoader.html#binary-name"> 500 * binary name</a> in the given module. 501 * 502 * <p> This method attempts to locate and load the class or interface. 503 * It does not link the class, and does not run the class initializer. 504 * If the class is not found, this method returns {@code null}. </p> 505 * 506 * <p> If the class loader of the given module defines other modules and 507 * the given name is a class defined in a different module, this method 508 * returns {@code null} after the class is loaded. </p> 509 * 510 * <p> This method does not check whether the requested class is 511 * accessible to its caller. </p> 512 * 513 * @apiNote 514 * This method returns {@code null} on failure rather than 515 * throwing a {@link ClassNotFoundException}, as is done by 516 * the {@link #forName(String, boolean, ClassLoader)} method. 517 * The security check is a stack-based permission check if the caller 518 * loads a class in another module. 519 * 520 * @param module A module 521 * @param name The <a href="ClassLoader.html#binary-name">binary name</a> 522 * of the class 523 * @return {@code Class} object of the given name defined in the given module; 524 * {@code null} if not found. 525 * 526 * @throws NullPointerException if the given module or name is {@code null} 527 * 528 * @throws LinkageError if the linkage fails 529 * 530 * @throws SecurityException 531 * <ul> 532 * <li> if the caller is not the specified module and 533 * {@code RuntimePermission("getClassLoader")} permission is denied; or</li> 534 * <li> access to the module content is denied. For example, 535 * permission check will be performed when a class loader calls 536 * {@link ModuleReader#open(String)} to read the bytes of a class file 537 * in a module.</li> 538 * </ul> 539 * 540 * @jls 12.2 Loading of Classes and Interfaces 541 * @jls 12.3 Linking of Classes and Interfaces 542 * @since 9 543 */ 544 @SuppressWarnings("removal") 545 @CallerSensitive 546 public static Class<?> forName(Module module, String name) { 547 Class<?> caller = null; 548 SecurityManager sm = System.getSecurityManager(); 549 if (sm != null) { 550 caller = Reflection.getCallerClass(); 551 } 552 return forName(module, name, caller); 553 } 554 555 // Caller-sensitive adapter method for reflective invocation 556 @SuppressWarnings("removal") 557 @CallerSensitiveAdapter 558 private static Class<?> forName(Module module, String name, Class<?> caller) { 559 Objects.requireNonNull(module); 560 Objects.requireNonNull(name); 561 562 ClassLoader cl; 563 SecurityManager sm = System.getSecurityManager(); 564 if (sm != null) { 565 if (caller != null && caller.getModule() != module) { 566 // if caller is null, Class.forName is the last java frame on the stack. 567 // java.base has all permissions 568 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION); 569 } 570 PrivilegedAction<ClassLoader> pa = module::getClassLoader; 571 cl = AccessController.doPrivileged(pa); 572 } else { 573 cl = module.getClassLoader(); 574 } 575 576 if (cl != null) { 577 return cl.loadClass(module, name); 578 } else { 579 return BootLoader.loadClass(module, name); 580 } 581 } 582 583 /** 584 * Creates a new instance of the class represented by this {@code Class} 585 * object. The class is instantiated as if by a {@code new} 586 * expression with an empty argument list. The class is initialized if it 587 * has not already been initialized. 588 * 589 * @deprecated This method propagates any exception thrown by the 590 * nullary constructor, including a checked exception. Use of 591 * this method effectively bypasses the compile-time exception 592 * checking that would otherwise be performed by the compiler. 593 * The {@link 594 * java.lang.reflect.Constructor#newInstance(java.lang.Object...) 595 * Constructor.newInstance} method avoids this problem by wrapping 596 * any exception thrown by the constructor in a (checked) {@link 597 * java.lang.reflect.InvocationTargetException}. 598 * 599 * <p>The call 600 * 601 * <pre>{@code 602 * clazz.newInstance() 603 * }</pre> 604 * 605 * can be replaced by 606 * 607 * <pre>{@code 608 * clazz.getDeclaredConstructor().newInstance() 609 * }</pre> 610 * 611 * The latter sequence of calls is inferred to be able to throw 612 * the additional exception types {@link 613 * InvocationTargetException} and {@link 614 * NoSuchMethodException}. Both of these exception types are 615 * subclasses of {@link ReflectiveOperationException}. 616 * 617 * @return a newly allocated instance of the class represented by this 618 * object. 619 * @throws IllegalAccessException if the class or its nullary 620 * constructor is not accessible. 621 * @throws InstantiationException 622 * if this {@code Class} represents an abstract class, 623 * an interface, an array class, a primitive type, or void; 624 * or if the class has no nullary constructor; 625 * or if the instantiation fails for some other reason. 626 * @throws ExceptionInInitializerError if the initialization 627 * provoked by this method fails. 628 * @throws SecurityException 629 * If a security manager, <i>s</i>, is present and 630 * the caller's class loader is not the same as or an 631 * ancestor of the class loader for the current class and 632 * invocation of {@link SecurityManager#checkPackageAccess 633 * s.checkPackageAccess()} denies access to the package 634 * of this class. 635 */ 636 @SuppressWarnings("removal") 637 @CallerSensitive 638 @Deprecated(since="9") 639 public T newInstance() 640 throws InstantiationException, IllegalAccessException 641 { 642 SecurityManager sm = System.getSecurityManager(); 643 if (sm != null) { 644 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false); 645 } 646 647 // Constructor lookup 648 Constructor<T> tmpConstructor = cachedConstructor; 649 if (tmpConstructor == null) { 650 if (this == Class.class) { 651 throw new IllegalAccessException( 652 "Can not call newInstance() on the Class for java.lang.Class" 653 ); 654 } 655 try { 656 Class<?>[] empty = {}; 657 final Constructor<T> c = getReflectionFactory().copyConstructor( 658 getConstructor0(empty, Member.DECLARED)); 659 // Disable accessibility checks on the constructor 660 // access check is done with the true caller 661 java.security.AccessController.doPrivileged( 662 new java.security.PrivilegedAction<>() { 663 public Void run() { 664 c.setAccessible(true); 665 return null; 666 } 667 }); 668 cachedConstructor = tmpConstructor = c; 669 } catch (NoSuchMethodException e) { 670 throw (InstantiationException) 671 new InstantiationException(getName()).initCause(e); 672 } 673 } 674 675 try { 676 Class<?> caller = Reflection.getCallerClass(); 677 return getReflectionFactory().newInstance(tmpConstructor, null, caller); 678 } catch (InvocationTargetException e) { 679 Unsafe.getUnsafe().throwException(e.getTargetException()); 680 // Not reached 681 return null; 682 } 683 } 684 685 private transient volatile Constructor<T> cachedConstructor; 686 687 /** 688 * Determines if the specified {@code Object} is assignment-compatible 689 * with the object represented by this {@code Class}. This method is 690 * the dynamic equivalent of the Java language {@code instanceof} 691 * operator. The method returns {@code true} if the specified 692 * {@code Object} argument is non-null and can be cast to the 693 * reference type represented by this {@code Class} object without 694 * raising a {@code ClassCastException.} It returns {@code false} 695 * otherwise. 696 * 697 * <p> Specifically, if this {@code Class} object represents a 698 * declared class, this method returns {@code true} if the specified 699 * {@code Object} argument is an instance of the represented class (or 700 * of any of its subclasses); it returns {@code false} otherwise. If 701 * this {@code Class} object represents an array class, this method 702 * returns {@code true} if the specified {@code Object} argument 703 * can be converted to an object of the array class by an identity 704 * conversion or by a widening reference conversion; it returns 705 * {@code false} otherwise. If this {@code Class} object 706 * represents an interface, this method returns {@code true} if the 707 * class or any superclass of the specified {@code Object} argument 708 * implements this interface; it returns {@code false} otherwise. If 709 * this {@code Class} object represents a primitive type, this method 710 * returns {@code false}. 711 * 712 * @param obj the object to check 713 * @return true if {@code obj} is an instance of this class 714 * 715 * @since 1.1 716 */ 717 @IntrinsicCandidate 718 public native boolean isInstance(Object obj); 719 720 721 /** 722 * Determines if the class or interface represented by this 723 * {@code Class} object is either the same as, or is a superclass or 724 * superinterface of, the class or interface represented by the specified 725 * {@code Class} parameter. It returns {@code true} if so; 726 * otherwise it returns {@code false}. If this {@code Class} 727 * object represents a primitive type, this method returns 728 * {@code true} if the specified {@code Class} parameter is 729 * exactly this {@code Class} object; otherwise it returns 730 * {@code false}. 731 * 732 * <p> Specifically, this method tests whether the type represented by the 733 * specified {@code Class} parameter can be converted to the type 734 * represented by this {@code Class} object via an identity conversion 735 * or via a widening reference conversion. See <cite>The Java Language 736 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4}, 737 * for details. 738 * 739 * @param cls the {@code Class} object to be checked 740 * @return the {@code boolean} value indicating whether objects of the 741 * type {@code cls} can be assigned to objects of this class 742 * @throws NullPointerException if the specified Class parameter is 743 * null. 744 * @since 1.1 745 */ 746 @IntrinsicCandidate 747 public native boolean isAssignableFrom(Class<?> cls); 748 749 750 /** 751 * Determines if this {@code Class} object represents an 752 * interface type. 753 * 754 * @return {@code true} if this {@code Class} object represents an interface; 755 * {@code false} otherwise. 756 */ 757 @IntrinsicCandidate 758 public native boolean isInterface(); 759 760 761 /** 762 * Determines if this {@code Class} object represents an array class. 763 * 764 * @return {@code true} if this {@code Class} object represents an array class; 765 * {@code false} otherwise. 766 * @since 1.1 767 */ 768 @IntrinsicCandidate 769 public native boolean isArray(); 770 771 772 /** 773 * Determines if the specified {@code Class} object represents a 774 * primitive type. 775 * 776 * <p> There are nine predefined {@code Class} objects to represent 777 * the eight primitive types and void. These are created by the Java 778 * Virtual Machine, and have the same names as the primitive types that 779 * they represent, namely {@code boolean}, {@code byte}, 780 * {@code char}, {@code short}, {@code int}, 781 * {@code long}, {@code float}, and {@code double}. 782 * 783 * <p> These objects may only be accessed via the following public static 784 * final variables, and are the only {@code Class} objects for which 785 * this method returns {@code true}. 786 * 787 * @return true if and only if this class represents a primitive type 788 * 789 * @see java.lang.Boolean#TYPE 790 * @see java.lang.Character#TYPE 791 * @see java.lang.Byte#TYPE 792 * @see java.lang.Short#TYPE 793 * @see java.lang.Integer#TYPE 794 * @see java.lang.Long#TYPE 795 * @see java.lang.Float#TYPE 796 * @see java.lang.Double#TYPE 797 * @see java.lang.Void#TYPE 798 * @since 1.1 799 */ 800 @IntrinsicCandidate 801 public native boolean isPrimitive(); 802 803 /** 804 * Returns true if this {@code Class} object represents an annotation 805 * interface. Note that if this method returns true, {@link #isInterface()} 806 * would also return true, as all annotation interfaces are also interfaces. 807 * 808 * @return {@code true} if this {@code Class} object represents an annotation 809 * interface; {@code false} otherwise 810 * @since 1.5 811 */ 812 public boolean isAnnotation() { 813 return (getModifiers() & ANNOTATION) != 0; 814 } 815 816 /** 817 *{@return {@code true} if and only if this class has the synthetic modifier 818 * bit set} 819 * 820 * @jls 13.1 The Form of a Binary 821 * @jvms 4.1 The {@code ClassFile} Structure 822 * @see <a 823 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java 824 * programming language and JVM modeling in core reflection</a> 825 * @since 1.5 826 */ 827 public boolean isSynthetic() { 828 return (getModifiers() & SYNTHETIC) != 0; 829 } 830 831 /** 832 * Returns the name of the entity (class, interface, array class, 833 * primitive type, or void) represented by this {@code Class} object. 834 * 835 * <p> If this {@code Class} object represents a class or interface, 836 * not an array class, then: 837 * <ul> 838 * <li> If the class or interface is not {@linkplain #isHidden() hidden}, 839 * then the <a href="ClassLoader.html#binary-name">binary name</a> 840 * of the class or interface is returned. 841 * <li> If the class or interface is hidden, then the result is a string 842 * of the form: {@code N + '/' + <suffix>} 843 * where {@code N} is the <a href="ClassLoader.html#binary-name">binary name</a> 844 * indicated by the {@code class} file passed to 845 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 846 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name. 847 * </ul> 848 * 849 * <p> If this {@code Class} object represents an array class, then 850 * the result is a string consisting of one or more '{@code [}' characters 851 * representing the depth of the array nesting, followed by the element 852 * type as encoded using the following table: 853 * 854 * <blockquote><table class="striped"> 855 * <caption style="display:none">Element types and encodings</caption> 856 * <thead> 857 * <tr><th scope="col"> Element Type <th scope="col"> Encoding 858 * </thead> 859 * <tbody style="text-align:left"> 860 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z} 861 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B} 862 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C} 863 * <tr><th scope="row"> class or interface with <a href="ClassLoader.html#binary-name">binary name</a> <i>N</i> 864 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;} 865 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D} 866 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F} 867 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I} 868 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J} 869 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S} 870 * </tbody> 871 * </table></blockquote> 872 * 873 * <p> If this {@code Class} object represents a primitive type or {@code void}, 874 * then the result is a string with the same spelling as the Java language 875 * keyword which corresponds to the primitive type or {@code void}. 876 * 877 * <p> Examples: 878 * <blockquote><pre> 879 * String.class.getName() 880 * returns "java.lang.String" 881 * byte.class.getName() 882 * returns "byte" 883 * (new Object[3]).getClass().getName() 884 * returns "[Ljava.lang.Object;" 885 * (new int[3][4][5][6][7][8][9]).getClass().getName() 886 * returns "[[[[[[[I" 887 * </pre></blockquote> 888 * 889 * @return the name of the class, interface, or other entity 890 * represented by this {@code Class} object. 891 * @jls 13.1 The Form of a Binary 892 */ 893 public String getName() { 894 String name = this.name; 895 return name != null ? name : initClassName(); 896 } 897 898 // Cache the name to reduce the number of calls into the VM. 899 // This field would be set by VM itself during initClassName call. 900 private transient String name; 901 private native String initClassName(); 902 903 /** 904 * Returns the class loader for the class. Some implementations may use 905 * null to represent the bootstrap class loader. This method will return 906 * null in such implementations if this class was loaded by the bootstrap 907 * class loader. 908 * 909 * <p>If this {@code Class} object 910 * represents a primitive type or void, null is returned. 911 * 912 * @return the class loader that loaded the class or interface 913 * represented by this {@code Class} object. 914 * @throws SecurityException 915 * if a security manager is present, and the caller's class loader 916 * is not {@code null} and is not the same as or an ancestor of the 917 * class loader for the class whose class loader is requested, 918 * and the caller does not have the 919 * {@link RuntimePermission}{@code ("getClassLoader")} 920 * @see java.lang.ClassLoader 921 * @see SecurityManager#checkPermission 922 * @see java.lang.RuntimePermission 923 */ 924 @CallerSensitive 925 @ForceInline // to ensure Reflection.getCallerClass optimization 926 public ClassLoader getClassLoader() { 927 ClassLoader cl = classLoader; 928 if (cl == null) 929 return null; 930 @SuppressWarnings("removal") 931 SecurityManager sm = System.getSecurityManager(); 932 if (sm != null) { 933 ClassLoader.checkClassLoaderPermission(cl, Reflection.getCallerClass()); 934 } 935 return cl; 936 } 937 938 // Package-private to allow ClassLoader access 939 ClassLoader getClassLoader0() { return classLoader; } 940 941 /** 942 * Returns the module that this class or interface is a member of. 943 * 944 * If this class represents an array type then this method returns the 945 * {@code Module} for the element type. If this class represents a 946 * primitive type or void, then the {@code Module} object for the 947 * {@code java.base} module is returned. 948 * 949 * If this class is in an unnamed module then the {@linkplain 950 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class 951 * loader for this class is returned. 952 * 953 * @return the module that this class or interface is a member of 954 * 955 * @since 9 956 */ 957 public Module getModule() { 958 return module; 959 } 960 961 // set by VM 962 private transient Module module; 963 964 // Initialized in JVM not by private constructor 965 // This field is filtered from reflection access, i.e. getDeclaredField 966 // will throw NoSuchFieldException 967 private final ClassLoader classLoader; 968 969 // Set by VM 970 private transient Object classData; 971 972 // package-private 973 Object getClassData() { 974 return classData; 975 } 976 977 /** 978 * Returns an array of {@code TypeVariable} objects that represent the 979 * type variables declared by the generic declaration represented by this 980 * {@code GenericDeclaration} object, in declaration order. Returns an 981 * array of length 0 if the underlying generic declaration declares no type 982 * variables. 983 * 984 * @return an array of {@code TypeVariable} objects that represent 985 * the type variables declared by this generic declaration 986 * @throws java.lang.reflect.GenericSignatureFormatError if the generic 987 * signature of this generic declaration does not conform to 988 * the format specified in section {@jvms 4.7.9} of 989 * <cite>The Java Virtual Machine Specification</cite> 990 * @since 1.5 991 */ 992 @SuppressWarnings("unchecked") 993 public TypeVariable<Class<T>>[] getTypeParameters() { 994 ClassRepository info = getGenericInfo(); 995 if (info != null) 996 return (TypeVariable<Class<T>>[])info.getTypeParameters(); 997 else 998 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0]; 999 } 1000 1001 1002 /** 1003 * Returns the {@code Class} representing the direct superclass of the 1004 * entity (class, interface, primitive type or void) represented by 1005 * this {@code Class}. If this {@code Class} represents either the 1006 * {@code Object} class, an interface, a primitive type, or void, then 1007 * null is returned. If this {@code Class} object represents an array class 1008 * then the {@code Class} object representing the {@code Object} class is 1009 * returned. 1010 * 1011 * @return the direct superclass of the class represented by this {@code Class} object 1012 */ 1013 @IntrinsicCandidate 1014 public native Class<? super T> getSuperclass(); 1015 1016 1017 /** 1018 * Returns the {@code Type} representing the direct superclass of 1019 * the entity (class, interface, primitive type or void) represented by 1020 * this {@code Class} object. 1021 * 1022 * <p>If the superclass is a parameterized type, the {@code Type} 1023 * object returned must accurately reflect the actual type 1024 * arguments used in the source code. The parameterized type 1025 * representing the superclass is created if it had not been 1026 * created before. See the declaration of {@link 1027 * java.lang.reflect.ParameterizedType ParameterizedType} for the 1028 * semantics of the creation process for parameterized types. If 1029 * this {@code Class} object represents either the {@code Object} 1030 * class, an interface, a primitive type, or void, then null is 1031 * returned. If this {@code Class} object represents an array class 1032 * then the {@code Class} object representing the {@code Object} class is 1033 * returned. 1034 * 1035 * @throws java.lang.reflect.GenericSignatureFormatError if the generic 1036 * class signature does not conform to the format specified in 1037 * section {@jvms 4.7.9} of <cite>The Java Virtual 1038 * Machine Specification</cite> 1039 * @throws TypeNotPresentException if the generic superclass 1040 * refers to a non-existent type declaration 1041 * @throws java.lang.reflect.MalformedParameterizedTypeException if the 1042 * generic superclass refers to a parameterized type that cannot be 1043 * instantiated for any reason 1044 * @return the direct superclass of the class represented by this {@code Class} object 1045 * @since 1.5 1046 */ 1047 public Type getGenericSuperclass() { 1048 ClassRepository info = getGenericInfo(); 1049 if (info == null) { 1050 return getSuperclass(); 1051 } 1052 1053 // Historical irregularity: 1054 // Generic signature marks interfaces with superclass = Object 1055 // but this API returns null for interfaces 1056 if (isInterface()) { 1057 return null; 1058 } 1059 1060 return info.getSuperclass(); 1061 } 1062 1063 /** 1064 * Gets the package of this class. 1065 * 1066 * <p>If this class represents an array type, a primitive type or void, 1067 * this method returns {@code null}. 1068 * 1069 * @return the package of this class. 1070 * @revised 9 1071 */ 1072 public Package getPackage() { 1073 if (isPrimitive() || isArray()) { 1074 return null; 1075 } 1076 ClassLoader cl = classLoader; 1077 return cl != null ? cl.definePackage(this) 1078 : BootLoader.definePackage(this); 1079 } 1080 1081 /** 1082 * Returns the fully qualified package name. 1083 * 1084 * <p> If this class is a top level class, then this method returns the fully 1085 * qualified name of the package that the class is a member of, or the 1086 * empty string if the class is in an unnamed package. 1087 * 1088 * <p> If this class is a member class, then this method is equivalent to 1089 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass 1090 * enclosing class}. 1091 * 1092 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain 1093 * #isAnonymousClass() anonymous class}, then this method is equivalent to 1094 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass 1095 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or 1096 * {@linkplain #getEnclosingConstructor enclosing constructor}. 1097 * 1098 * <p> If this class represents an array type then this method returns the 1099 * package name of the element type. If this class represents a primitive 1100 * type or void then the package name "{@code java.lang}" is returned. 1101 * 1102 * @return the fully qualified package name 1103 * 1104 * @since 9 1105 * @jls 6.7 Fully Qualified Names 1106 */ 1107 public String getPackageName() { 1108 String pn = this.packageName; 1109 if (pn == null) { 1110 Class<?> c = isArray() ? elementType() : this; 1111 if (c.isPrimitive()) { 1112 pn = "java.lang"; 1113 } else { 1114 String cn = c.getName(); 1115 int dot = cn.lastIndexOf('.'); 1116 pn = (dot != -1) ? cn.substring(0, dot).intern() : ""; 1117 } 1118 this.packageName = pn; 1119 } 1120 return pn; 1121 } 1122 1123 // cached package name 1124 private transient String packageName; 1125 1126 /** 1127 * Returns the interfaces directly implemented by the class or interface 1128 * represented by this {@code Class} object. 1129 * 1130 * <p>If this {@code Class} object represents a class, the return value is an array 1131 * containing objects representing all interfaces directly implemented by 1132 * the class. The order of the interface objects in the array corresponds 1133 * to the order of the interface names in the {@code implements} clause of 1134 * the declaration of the class represented by this {@code Class} object. For example, 1135 * given the declaration: 1136 * <blockquote> 1137 * {@code class Shimmer implements FloorWax, DessertTopping { ... }} 1138 * </blockquote> 1139 * suppose the value of {@code s} is an instance of 1140 * {@code Shimmer}; the value of the expression: 1141 * <blockquote> 1142 * {@code s.getClass().getInterfaces()[0]} 1143 * </blockquote> 1144 * is the {@code Class} object that represents interface 1145 * {@code FloorWax}; and the value of: 1146 * <blockquote> 1147 * {@code s.getClass().getInterfaces()[1]} 1148 * </blockquote> 1149 * is the {@code Class} object that represents interface 1150 * {@code DessertTopping}. 1151 * 1152 * <p>If this {@code Class} object represents an interface, the array contains objects 1153 * representing all interfaces directly extended by the interface. The 1154 * order of the interface objects in the array corresponds to the order of 1155 * the interface names in the {@code extends} clause of the declaration of 1156 * the interface represented by this {@code Class} object. 1157 * 1158 * <p>If this {@code Class} object represents a class or interface that implements no 1159 * interfaces, the method returns an array of length 0. 1160 * 1161 * <p>If this {@code Class} object represents a primitive type or void, the method 1162 * returns an array of length 0. 1163 * 1164 * <p>If this {@code Class} object represents an array type, the 1165 * interfaces {@code Cloneable} and {@code java.io.Serializable} are 1166 * returned in that order. 1167 * 1168 * @return an array of interfaces directly implemented by this class 1169 */ 1170 public Class<?>[] getInterfaces() { 1171 // defensively copy before handing over to user code 1172 return getInterfaces(true); 1173 } 1174 1175 private Class<?>[] getInterfaces(boolean cloneArray) { 1176 ReflectionData<T> rd = reflectionData(); 1177 if (rd == null) { 1178 // no cloning required 1179 return getInterfaces0(); 1180 } else { 1181 Class<?>[] interfaces = rd.interfaces; 1182 if (interfaces == null) { 1183 interfaces = getInterfaces0(); 1184 rd.interfaces = interfaces; 1185 } 1186 // defensively copy if requested 1187 return cloneArray ? interfaces.clone() : interfaces; 1188 } 1189 } 1190 1191 private native Class<?>[] getInterfaces0(); 1192 1193 /** 1194 * Returns the {@code Type}s representing the interfaces 1195 * directly implemented by the class or interface represented by 1196 * this {@code Class} object. 1197 * 1198 * <p>If a superinterface is a parameterized type, the 1199 * {@code Type} object returned for it must accurately reflect 1200 * the actual type arguments used in the source code. The 1201 * parameterized type representing each superinterface is created 1202 * if it had not been created before. See the declaration of 1203 * {@link java.lang.reflect.ParameterizedType ParameterizedType} 1204 * for the semantics of the creation process for parameterized 1205 * types. 1206 * 1207 * <p>If this {@code Class} object represents a class, the return value is an array 1208 * containing objects representing all interfaces directly implemented by 1209 * the class. The order of the interface objects in the array corresponds 1210 * to the order of the interface names in the {@code implements} clause of 1211 * the declaration of the class represented by this {@code Class} object. 1212 * 1213 * <p>If this {@code Class} object represents an interface, the array contains objects 1214 * representing all interfaces directly extended by the interface. The 1215 * order of the interface objects in the array corresponds to the order of 1216 * the interface names in the {@code extends} clause of the declaration of 1217 * the interface represented by this {@code Class} object. 1218 * 1219 * <p>If this {@code Class} object represents a class or interface that implements no 1220 * interfaces, the method returns an array of length 0. 1221 * 1222 * <p>If this {@code Class} object represents a primitive type or void, the method 1223 * returns an array of length 0. 1224 * 1225 * <p>If this {@code Class} object represents an array type, the 1226 * interfaces {@code Cloneable} and {@code java.io.Serializable} are 1227 * returned in that order. 1228 * 1229 * @throws java.lang.reflect.GenericSignatureFormatError 1230 * if the generic class signature does not conform to the 1231 * format specified in section {@jvms 4.7.9} of <cite>The 1232 * Java Virtual Machine Specification</cite> 1233 * @throws TypeNotPresentException if any of the generic 1234 * superinterfaces refers to a non-existent type declaration 1235 * @throws java.lang.reflect.MalformedParameterizedTypeException 1236 * if any of the generic superinterfaces refer to a parameterized 1237 * type that cannot be instantiated for any reason 1238 * @return an array of interfaces directly implemented by this class 1239 * @since 1.5 1240 */ 1241 public Type[] getGenericInterfaces() { 1242 ClassRepository info = getGenericInfo(); 1243 return (info == null) ? getInterfaces() : info.getSuperInterfaces(); 1244 } 1245 1246 1247 /** 1248 * Returns the {@code Class} representing the component type of an 1249 * array. If this class does not represent an array class this method 1250 * returns null. 1251 * 1252 * @return the {@code Class} representing the component type of this 1253 * class if this class is an array 1254 * @see java.lang.reflect.Array 1255 * @since 1.1 1256 */ 1257 public Class<?> getComponentType() { 1258 // Only return for array types. Storage may be reused for Class for instance types. 1259 if (isArray()) { 1260 return componentType; 1261 } else { 1262 return null; 1263 } 1264 } 1265 1266 private final Class<?> componentType; 1267 1268 /* 1269 * Returns the {@code Class} representing the element type of an array class. 1270 * If this class does not represent an array class, then this method returns 1271 * {@code null}. 1272 */ 1273 private Class<?> elementType() { 1274 if (!isArray()) return null; 1275 1276 Class<?> c = this; 1277 while (c.isArray()) { 1278 c = c.getComponentType(); 1279 } 1280 return c; 1281 } 1282 1283 /** 1284 * Returns the Java language modifiers for this class or interface, encoded 1285 * in an integer. The modifiers consist of the Java Virtual Machine's 1286 * constants for {@code public}, {@code protected}, 1287 * {@code private}, {@code final}, {@code static}, 1288 * {@code abstract} and {@code interface}; they should be decoded 1289 * using the methods of class {@code Modifier}. 1290 * 1291 * <p> If the underlying class is an array class, then its 1292 * {@code public}, {@code private} and {@code protected} 1293 * modifiers are the same as those of its component type. If this 1294 * {@code Class} object represents a primitive type or void, its 1295 * {@code public} modifier is always {@code true}, and its 1296 * {@code protected} and {@code private} modifiers are always 1297 * {@code false}. If this {@code Class} object represents an array class, a 1298 * primitive type or void, then its {@code final} modifier is always 1299 * {@code true} and its interface modifier is always 1300 * {@code false}. The values of its other modifiers are not determined 1301 * by this specification. 1302 * 1303 * <p> The modifier encodings are defined in section {@jvms 4.1} 1304 * of <cite>The Java Virtual Machine Specification</cite>. 1305 * 1306 * @return the {@code int} representing the modifiers for this class 1307 * @see java.lang.reflect.Modifier 1308 * @see <a 1309 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java 1310 * programming language and JVM modeling in core reflection</a> 1311 * @since 1.1 1312 * @jls 8.1.1 Class Modifiers 1313 * @jls 9.1.1. Interface Modifiers 1314 */ 1315 @IntrinsicCandidate 1316 public native int getModifiers(); 1317 1318 1319 /** 1320 * Gets the signers of this class. 1321 * 1322 * @return the signers of this class, or null if there are no signers. In 1323 * particular, this method returns null if this {@code Class} object represents 1324 * a primitive type or void. 1325 * @since 1.1 1326 */ 1327 public native Object[] getSigners(); 1328 1329 1330 /** 1331 * Set the signers of this class. 1332 */ 1333 native void setSigners(Object[] signers); 1334 1335 1336 /** 1337 * If this {@code Class} object represents a local or anonymous 1338 * class within a method, returns a {@link 1339 * java.lang.reflect.Method Method} object representing the 1340 * immediately enclosing method of the underlying class. Returns 1341 * {@code null} otherwise. 1342 * 1343 * In particular, this method returns {@code null} if the underlying 1344 * class is a local or anonymous class immediately enclosed by a class or 1345 * interface declaration, instance initializer or static initializer. 1346 * 1347 * @return the immediately enclosing method of the underlying class, if 1348 * that class is a local or anonymous class; otherwise {@code null}. 1349 * 1350 * @throws SecurityException 1351 * If a security manager, <i>s</i>, is present and any of the 1352 * following conditions is met: 1353 * 1354 * <ul> 1355 * 1356 * <li> the caller's class loader is not the same as the 1357 * class loader of the enclosing class and invocation of 1358 * {@link SecurityManager#checkPermission 1359 * s.checkPermission} method with 1360 * {@code RuntimePermission("accessDeclaredMembers")} 1361 * denies access to the methods within the enclosing class 1362 * 1363 * <li> the caller's class loader is not the same as or an 1364 * ancestor of the class loader for the enclosing class and 1365 * invocation of {@link SecurityManager#checkPackageAccess 1366 * s.checkPackageAccess()} denies access to the package 1367 * of the enclosing class 1368 * 1369 * </ul> 1370 * @since 1.5 1371 */ 1372 @CallerSensitive 1373 public Method getEnclosingMethod() throws SecurityException { 1374 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo(); 1375 1376 if (enclosingInfo == null) 1377 return null; 1378 else { 1379 if (!enclosingInfo.isMethod()) 1380 return null; 1381 1382 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(), 1383 getFactory()); 1384 Class<?> returnType = toClass(typeInfo.getReturnType()); 1385 Type [] parameterTypes = typeInfo.getParameterTypes(); 1386 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length]; 1387 1388 // Convert Types to Classes; returned types *should* 1389 // be class objects since the methodDescriptor's used 1390 // don't have generics information 1391 for(int i = 0; i < parameterClasses.length; i++) 1392 parameterClasses[i] = toClass(parameterTypes[i]); 1393 1394 // Perform access check 1395 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass(); 1396 @SuppressWarnings("removal") 1397 SecurityManager sm = System.getSecurityManager(); 1398 if (sm != null) { 1399 enclosingCandidate.checkMemberAccess(sm, Member.DECLARED, 1400 Reflection.getCallerClass(), true); 1401 } 1402 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false); 1403 1404 /* 1405 * Loop over all declared methods; match method name, 1406 * number of and type of parameters, *and* return 1407 * type. Matching return type is also necessary 1408 * because of covariant returns, etc. 1409 */ 1410 ReflectionFactory fact = getReflectionFactory(); 1411 for (Method m : candidates) { 1412 if (m.getName().equals(enclosingInfo.getName()) && 1413 arrayContentsEq(parameterClasses, 1414 fact.getExecutableSharedParameterTypes(m))) { 1415 // finally, check return type 1416 if (m.getReturnType().equals(returnType)) { 1417 return fact.copyMethod(m); 1418 } 1419 } 1420 } 1421 1422 throw new InternalError("Enclosing method not found"); 1423 } 1424 } 1425 1426 private native Object[] getEnclosingMethod0(); 1427 1428 private EnclosingMethodInfo getEnclosingMethodInfo() { 1429 Object[] enclosingInfo = getEnclosingMethod0(); 1430 if (enclosingInfo == null) 1431 return null; 1432 else { 1433 return new EnclosingMethodInfo(enclosingInfo); 1434 } 1435 } 1436 1437 private static final class EnclosingMethodInfo { 1438 private final Class<?> enclosingClass; 1439 private final String name; 1440 private final String descriptor; 1441 1442 static void validate(Object[] enclosingInfo) { 1443 if (enclosingInfo.length != 3) 1444 throw new InternalError("Malformed enclosing method information"); 1445 try { 1446 // The array is expected to have three elements: 1447 1448 // the immediately enclosing class 1449 Class<?> enclosingClass = (Class<?>)enclosingInfo[0]; 1450 assert(enclosingClass != null); 1451 1452 // the immediately enclosing method or constructor's 1453 // name (can be null). 1454 String name = (String)enclosingInfo[1]; 1455 1456 // the immediately enclosing method or constructor's 1457 // descriptor (null iff name is). 1458 String descriptor = (String)enclosingInfo[2]; 1459 assert((name != null && descriptor != null) || name == descriptor); 1460 } catch (ClassCastException cce) { 1461 throw new InternalError("Invalid type in enclosing method information", cce); 1462 } 1463 } 1464 1465 EnclosingMethodInfo(Object[] enclosingInfo) { 1466 validate(enclosingInfo); 1467 this.enclosingClass = (Class<?>)enclosingInfo[0]; 1468 this.name = (String)enclosingInfo[1]; 1469 this.descriptor = (String)enclosingInfo[2]; 1470 } 1471 1472 boolean isPartial() { 1473 return enclosingClass == null || name == null || descriptor == null; 1474 } 1475 1476 boolean isConstructor() { return !isPartial() && "<init>".equals(name); } 1477 1478 boolean isMethod() { return !isPartial() && !isConstructor() && !"<clinit>".equals(name); } 1479 1480 Class<?> getEnclosingClass() { return enclosingClass; } 1481 1482 String getName() { return name; } 1483 1484 String getDescriptor() { return descriptor; } 1485 1486 } 1487 1488 private static Class<?> toClass(Type o) { 1489 if (o instanceof GenericArrayType) 1490 return Array.newInstance(toClass(((GenericArrayType)o).getGenericComponentType()), 1491 0) 1492 .getClass(); 1493 return (Class<?>)o; 1494 } 1495 1496 /** 1497 * If this {@code Class} object represents a local or anonymous 1498 * class within a constructor, returns a {@link 1499 * java.lang.reflect.Constructor Constructor} object representing 1500 * the immediately enclosing constructor of the underlying 1501 * class. Returns {@code null} otherwise. In particular, this 1502 * method returns {@code null} if the underlying class is a local 1503 * or anonymous class immediately enclosed by a class or 1504 * interface declaration, instance initializer or static initializer. 1505 * 1506 * @return the immediately enclosing constructor of the underlying class, if 1507 * that class is a local or anonymous class; otherwise {@code null}. 1508 * @throws SecurityException 1509 * If a security manager, <i>s</i>, is present and any of the 1510 * following conditions is met: 1511 * 1512 * <ul> 1513 * 1514 * <li> the caller's class loader is not the same as the 1515 * class loader of the enclosing class and invocation of 1516 * {@link SecurityManager#checkPermission 1517 * s.checkPermission} method with 1518 * {@code RuntimePermission("accessDeclaredMembers")} 1519 * denies access to the constructors within the enclosing class 1520 * 1521 * <li> the caller's class loader is not the same as or an 1522 * ancestor of the class loader for the enclosing class and 1523 * invocation of {@link SecurityManager#checkPackageAccess 1524 * s.checkPackageAccess()} denies access to the package 1525 * of the enclosing class 1526 * 1527 * </ul> 1528 * @since 1.5 1529 */ 1530 @CallerSensitive 1531 public Constructor<?> getEnclosingConstructor() throws SecurityException { 1532 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo(); 1533 1534 if (enclosingInfo == null) 1535 return null; 1536 else { 1537 if (!enclosingInfo.isConstructor()) 1538 return null; 1539 1540 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(), 1541 getFactory()); 1542 Type [] parameterTypes = typeInfo.getParameterTypes(); 1543 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length]; 1544 1545 // Convert Types to Classes; returned types *should* 1546 // be class objects since the methodDescriptor's used 1547 // don't have generics information 1548 for(int i = 0; i < parameterClasses.length; i++) 1549 parameterClasses[i] = toClass(parameterTypes[i]); 1550 1551 // Perform access check 1552 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass(); 1553 @SuppressWarnings("removal") 1554 SecurityManager sm = System.getSecurityManager(); 1555 if (sm != null) { 1556 enclosingCandidate.checkMemberAccess(sm, Member.DECLARED, 1557 Reflection.getCallerClass(), true); 1558 } 1559 1560 Constructor<?>[] candidates = enclosingCandidate 1561 .privateGetDeclaredConstructors(false); 1562 /* 1563 * Loop over all declared constructors; match number 1564 * of and type of parameters. 1565 */ 1566 ReflectionFactory fact = getReflectionFactory(); 1567 for (Constructor<?> c : candidates) { 1568 if (arrayContentsEq(parameterClasses, 1569 fact.getExecutableSharedParameterTypes(c))) { 1570 return fact.copyConstructor(c); 1571 } 1572 } 1573 1574 throw new InternalError("Enclosing constructor not found"); 1575 } 1576 } 1577 1578 1579 /** 1580 * If the class or interface represented by this {@code Class} object 1581 * is a member of another class, returns the {@code Class} object 1582 * representing the class in which it was declared. This method returns 1583 * null if this class or interface is not a member of any other class. If 1584 * this {@code Class} object represents an array class, a primitive 1585 * type, or void, then this method returns null. 1586 * 1587 * @return the declaring class for this class 1588 * @throws SecurityException 1589 * If a security manager, <i>s</i>, is present and the caller's 1590 * class loader is not the same as or an ancestor of the class 1591 * loader for the declaring class and invocation of {@link 1592 * SecurityManager#checkPackageAccess s.checkPackageAccess()} 1593 * denies access to the package of the declaring class 1594 * @since 1.1 1595 */ 1596 @CallerSensitive 1597 public Class<?> getDeclaringClass() throws SecurityException { 1598 final Class<?> candidate = getDeclaringClass0(); 1599 1600 if (candidate != null) { 1601 @SuppressWarnings("removal") 1602 SecurityManager sm = System.getSecurityManager(); 1603 if (sm != null) { 1604 candidate.checkPackageAccess(sm, 1605 ClassLoader.getClassLoader(Reflection.getCallerClass()), true); 1606 } 1607 } 1608 return candidate; 1609 } 1610 1611 private native Class<?> getDeclaringClass0(); 1612 1613 1614 /** 1615 * Returns the immediately enclosing class of the underlying 1616 * class. If the underlying class is a top level class this 1617 * method returns {@code null}. 1618 * @return the immediately enclosing class of the underlying class 1619 * @throws SecurityException 1620 * If a security manager, <i>s</i>, is present and the caller's 1621 * class loader is not the same as or an ancestor of the class 1622 * loader for the enclosing class and invocation of {@link 1623 * SecurityManager#checkPackageAccess s.checkPackageAccess()} 1624 * denies access to the package of the enclosing class 1625 * @since 1.5 1626 */ 1627 @CallerSensitive 1628 public Class<?> getEnclosingClass() throws SecurityException { 1629 // There are five kinds of classes (or interfaces): 1630 // a) Top level classes 1631 // b) Nested classes (static member classes) 1632 // c) Inner classes (non-static member classes) 1633 // d) Local classes (named classes declared within a method) 1634 // e) Anonymous classes 1635 1636 1637 // JVM Spec 4.7.7: A class must have an EnclosingMethod 1638 // attribute if and only if it is a local class or an 1639 // anonymous class. 1640 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo(); 1641 Class<?> enclosingCandidate; 1642 1643 if (enclosingInfo == null) { 1644 // This is a top level or a nested class or an inner class (a, b, or c) 1645 enclosingCandidate = getDeclaringClass0(); 1646 } else { 1647 Class<?> enclosingClass = enclosingInfo.getEnclosingClass(); 1648 // This is a local class or an anonymous class (d or e) 1649 if (enclosingClass == this || enclosingClass == null) 1650 throw new InternalError("Malformed enclosing method information"); 1651 else 1652 enclosingCandidate = enclosingClass; 1653 } 1654 1655 if (enclosingCandidate != null) { 1656 @SuppressWarnings("removal") 1657 SecurityManager sm = System.getSecurityManager(); 1658 if (sm != null) { 1659 enclosingCandidate.checkPackageAccess(sm, 1660 ClassLoader.getClassLoader(Reflection.getCallerClass()), true); 1661 } 1662 } 1663 return enclosingCandidate; 1664 } 1665 1666 /** 1667 * Returns the simple name of the underlying class as given in the 1668 * source code. An empty string is returned if the underlying class is 1669 * {@linkplain #isAnonymousClass() anonymous}. 1670 * A {@linkplain #isSynthetic() synthetic class}, one not present 1671 * in source code, can have a non-empty name including special 1672 * characters, such as "{@code $}". 1673 * 1674 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the 1675 * component type with "[]" appended. In particular the simple 1676 * name of an array class whose component type is anonymous is "[]". 1677 * 1678 * @return the simple name of the underlying class 1679 * @since 1.5 1680 */ 1681 public String getSimpleName() { 1682 ReflectionData<T> rd = reflectionData(); 1683 String simpleName = rd.simpleName; 1684 if (simpleName == null) { 1685 rd.simpleName = simpleName = getSimpleName0(); 1686 } 1687 return simpleName; 1688 } 1689 1690 private String getSimpleName0() { 1691 if (isArray()) { 1692 return getComponentType().getSimpleName().concat("[]"); 1693 } 1694 String simpleName = getSimpleBinaryName(); 1695 if (simpleName == null) { // top level class 1696 simpleName = getName(); 1697 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name 1698 } 1699 return simpleName; 1700 } 1701 1702 /** 1703 * Return an informative string for the name of this class or interface. 1704 * 1705 * @return an informative string for the name of this class or interface 1706 * @since 1.8 1707 */ 1708 public String getTypeName() { 1709 if (isArray()) { 1710 try { 1711 Class<?> cl = this; 1712 int dimensions = 0; 1713 do { 1714 dimensions++; 1715 cl = cl.getComponentType(); 1716 } while (cl.isArray()); 1717 return cl.getName().concat("[]".repeat(dimensions)); 1718 } catch (Throwable e) { /*FALLTHRU*/ } 1719 } 1720 return getName(); 1721 } 1722 1723 /** 1724 * Returns the canonical name of the underlying class as 1725 * defined by <cite>The Java Language Specification</cite>. 1726 * Returns {@code null} if the underlying class does not have a canonical 1727 * name. Classes without canonical names include: 1728 * <ul> 1729 * <li>a {@linkplain #isLocalClass() local class} 1730 * <li>a {@linkplain #isAnonymousClass() anonymous class} 1731 * <li>a {@linkplain #isHidden() hidden class} 1732 * <li>an array whose component type does not have a canonical name</li> 1733 * </ul> 1734 * 1735 * The canonical name for a primitive class is the keyword for the 1736 * corresponding primitive type ({@code byte}, {@code short}, 1737 * {@code char}, {@code int}, and so on). 1738 * 1739 * <p>An array type has a canonical name if and only if its 1740 * component type has a canonical name. When an array type has a 1741 * canonical name, it is equal to the canonical name of the 1742 * component type followed by "{@code []}". 1743 * 1744 * @return the canonical name of the underlying class if it exists, and 1745 * {@code null} otherwise. 1746 * @jls 6.7 Fully Qualified Names and Canonical Names 1747 * @since 1.5 1748 */ 1749 public String getCanonicalName() { 1750 ReflectionData<T> rd = reflectionData(); 1751 String canonicalName = rd.canonicalName; 1752 if (canonicalName == null) { 1753 rd.canonicalName = canonicalName = getCanonicalName0(); 1754 } 1755 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName; 1756 } 1757 1758 private String getCanonicalName0() { 1759 if (isArray()) { 1760 String canonicalName = getComponentType().getCanonicalName(); 1761 if (canonicalName != null) 1762 return canonicalName.concat("[]"); 1763 else 1764 return ReflectionData.NULL_SENTINEL; 1765 } 1766 if (isHidden() || isLocalOrAnonymousClass()) 1767 return ReflectionData.NULL_SENTINEL; 1768 Class<?> enclosingClass = getEnclosingClass(); 1769 if (enclosingClass == null) { // top level class 1770 return getName(); 1771 } else { 1772 String enclosingName = enclosingClass.getCanonicalName(); 1773 if (enclosingName == null) 1774 return ReflectionData.NULL_SENTINEL; 1775 String simpleName = getSimpleName(); 1776 return new StringBuilder(enclosingName.length() + simpleName.length() + 1) 1777 .append(enclosingName) 1778 .append('.') 1779 .append(simpleName) 1780 .toString(); 1781 } 1782 } 1783 1784 /** 1785 * Returns {@code true} if and only if the underlying class 1786 * is an anonymous class. 1787 * 1788 * @apiNote 1789 * An anonymous class is not a {@linkplain #isHidden() hidden class}. 1790 * 1791 * @return {@code true} if and only if this class is an anonymous class. 1792 * @since 1.5 1793 * @jls 15.9.5 Anonymous Class Declarations 1794 */ 1795 public boolean isAnonymousClass() { 1796 return !isArray() && isLocalOrAnonymousClass() && 1797 getSimpleBinaryName0() == null; 1798 } 1799 1800 /** 1801 * Returns {@code true} if and only if the underlying class 1802 * is a local class. 1803 * 1804 * @return {@code true} if and only if this class is a local class. 1805 * @since 1.5 1806 * @jls 14.3 Local Class Declarations 1807 */ 1808 public boolean isLocalClass() { 1809 return isLocalOrAnonymousClass() && 1810 (isArray() || getSimpleBinaryName0() != null); 1811 } 1812 1813 /** 1814 * Returns {@code true} if and only if the underlying class 1815 * is a member class. 1816 * 1817 * @return {@code true} if and only if this class is a member class. 1818 * @since 1.5 1819 * @jls 8.5 Member Type Declarations 1820 */ 1821 public boolean isMemberClass() { 1822 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null; 1823 } 1824 1825 /** 1826 * Returns the "simple binary name" of the underlying class, i.e., 1827 * the binary name without the leading enclosing class name. 1828 * Returns {@code null} if the underlying class is a top level 1829 * class. 1830 */ 1831 private String getSimpleBinaryName() { 1832 if (isTopLevelClass()) 1833 return null; 1834 String name = getSimpleBinaryName0(); 1835 if (name == null) // anonymous class 1836 return ""; 1837 return name; 1838 } 1839 1840 private native String getSimpleBinaryName0(); 1841 1842 /** 1843 * Returns {@code true} if this is a top level class. Returns {@code false} 1844 * otherwise. 1845 */ 1846 private boolean isTopLevelClass() { 1847 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null; 1848 } 1849 1850 /** 1851 * Returns {@code true} if this is a local class or an anonymous 1852 * class. Returns {@code false} otherwise. 1853 */ 1854 private boolean isLocalOrAnonymousClass() { 1855 // JVM Spec 4.7.7: A class must have an EnclosingMethod 1856 // attribute if and only if it is a local class or an 1857 // anonymous class. 1858 return hasEnclosingMethodInfo(); 1859 } 1860 1861 private boolean hasEnclosingMethodInfo() { 1862 Object[] enclosingInfo = getEnclosingMethod0(); 1863 if (enclosingInfo != null) { 1864 EnclosingMethodInfo.validate(enclosingInfo); 1865 return true; 1866 } 1867 return false; 1868 } 1869 1870 /** 1871 * Returns an array containing {@code Class} objects representing all 1872 * the public classes and interfaces that are members of the class 1873 * represented by this {@code Class} object. This includes public 1874 * class and interface members inherited from superclasses and public class 1875 * and interface members declared by the class. This method returns an 1876 * array of length 0 if this {@code Class} object has no public member 1877 * classes or interfaces. This method also returns an array of length 0 if 1878 * this {@code Class} object represents a primitive type, an array 1879 * class, or void. 1880 * 1881 * @return the array of {@code Class} objects representing the public 1882 * members of this class 1883 * @throws SecurityException 1884 * If a security manager, <i>s</i>, is present and 1885 * the caller's class loader is not the same as or an 1886 * ancestor of the class loader for the current class and 1887 * invocation of {@link SecurityManager#checkPackageAccess 1888 * s.checkPackageAccess()} denies access to the package 1889 * of this class. 1890 * 1891 * @since 1.1 1892 */ 1893 @SuppressWarnings("removal") 1894 @CallerSensitive 1895 public Class<?>[] getClasses() { 1896 SecurityManager sm = System.getSecurityManager(); 1897 if (sm != null) { 1898 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false); 1899 } 1900 1901 // Privileged so this implementation can look at DECLARED classes, 1902 // something the caller might not have privilege to do. The code here 1903 // is allowed to look at DECLARED classes because (1) it does not hand 1904 // out anything other than public members and (2) public member access 1905 // has already been ok'd by the SecurityManager. 1906 1907 return java.security.AccessController.doPrivileged( 1908 new java.security.PrivilegedAction<>() { 1909 public Class<?>[] run() { 1910 List<Class<?>> list = new ArrayList<>(); 1911 Class<?> currentClass = Class.this; 1912 while (currentClass != null) { 1913 for (Class<?> m : currentClass.getDeclaredClasses()) { 1914 if (Modifier.isPublic(m.getModifiers())) { 1915 list.add(m); 1916 } 1917 } 1918 currentClass = currentClass.getSuperclass(); 1919 } 1920 return list.toArray(new Class<?>[0]); 1921 } 1922 }); 1923 } 1924 1925 1926 /** 1927 * Returns an array containing {@code Field} objects reflecting all 1928 * the accessible public fields of the class or interface represented by 1929 * this {@code Class} object. 1930 * 1931 * <p> If this {@code Class} object represents a class or interface with 1932 * no accessible public fields, then this method returns an array of length 1933 * 0. 1934 * 1935 * <p> If this {@code Class} object represents a class, then this method 1936 * returns the public fields of the class and of all its superclasses and 1937 * superinterfaces. 1938 * 1939 * <p> If this {@code Class} object represents an interface, then this 1940 * method returns the fields of the interface and of all its 1941 * superinterfaces. 1942 * 1943 * <p> If this {@code Class} object represents an array type, a primitive 1944 * type, or void, then this method returns an array of length 0. 1945 * 1946 * <p> The elements in the returned array are not sorted and are not in any 1947 * particular order. 1948 * 1949 * @return the array of {@code Field} objects representing the 1950 * public fields 1951 * @throws SecurityException 1952 * If a security manager, <i>s</i>, is present and 1953 * the caller's class loader is not the same as or an 1954 * ancestor of the class loader for the current class and 1955 * invocation of {@link SecurityManager#checkPackageAccess 1956 * s.checkPackageAccess()} denies access to the package 1957 * of this class. 1958 * 1959 * @since 1.1 1960 * @jls 8.2 Class Members 1961 * @jls 8.3 Field Declarations 1962 */ 1963 @CallerSensitive 1964 public Field[] getFields() throws SecurityException { 1965 @SuppressWarnings("removal") 1966 SecurityManager sm = System.getSecurityManager(); 1967 if (sm != null) { 1968 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true); 1969 } 1970 return copyFields(privateGetPublicFields()); 1971 } 1972 1973 1974 /** 1975 * Returns an array containing {@code Method} objects reflecting all the 1976 * public methods of the class or interface represented by this {@code 1977 * Class} object, including those declared by the class or interface and 1978 * those inherited from superclasses and superinterfaces. 1979 * 1980 * <p> If this {@code Class} object represents an array type, then the 1981 * returned array has a {@code Method} object for each of the public 1982 * methods inherited by the array type from {@code Object}. It does not 1983 * contain a {@code Method} object for {@code clone()}. 1984 * 1985 * <p> If this {@code Class} object represents an interface then the 1986 * returned array does not contain any implicitly declared methods from 1987 * {@code Object}. Therefore, if no methods are explicitly declared in 1988 * this interface or any of its superinterfaces then the returned array 1989 * has length 0. (Note that a {@code Class} object which represents a class 1990 * always has public methods, inherited from {@code Object}.) 1991 * 1992 * <p> The returned array never contains methods with names "{@code <init>}" 1993 * or "{@code <clinit>}". 1994 * 1995 * <p> The elements in the returned array are not sorted and are not in any 1996 * particular order. 1997 * 1998 * <p> Generally, the result is computed as with the following 4 step algorithm. 1999 * Let C be the class or interface represented by this {@code Class} object: 2000 * <ol> 2001 * <li> A union of methods is composed of: 2002 * <ol type="a"> 2003 * <li> C's declared public instance and static methods as returned by 2004 * {@link #getDeclaredMethods()} and filtered to include only public 2005 * methods.</li> 2006 * <li> If C is a class other than {@code Object}, then include the result 2007 * of invoking this algorithm recursively on the superclass of C.</li> 2008 * <li> Include the results of invoking this algorithm recursively on all 2009 * direct superinterfaces of C, but include only instance methods.</li> 2010 * </ol></li> 2011 * <li> Union from step 1 is partitioned into subsets of methods with same 2012 * signature (name, parameter types) and return type.</li> 2013 * <li> Within each such subset only the most specific methods are selected. 2014 * Let method M be a method from a set of methods with same signature 2015 * and return type. M is most specific if there is no such method 2016 * N != M from the same set, such that N is more specific than M. 2017 * N is more specific than M if: 2018 * <ol type="a"> 2019 * <li> N is declared by a class and M is declared by an interface; or</li> 2020 * <li> N and M are both declared by classes or both by interfaces and 2021 * N's declaring type is the same as or a subtype of M's declaring type 2022 * (clearly, if M's and N's declaring types are the same type, then 2023 * M and N are the same method).</li> 2024 * </ol></li> 2025 * <li> The result of this algorithm is the union of all selected methods from 2026 * step 3.</li> 2027 * </ol> 2028 * 2029 * @apiNote There may be more than one method with a particular name 2030 * and parameter types in a class because while the Java language forbids a 2031 * class to declare multiple methods with the same signature but different 2032 * return types, the Java virtual machine does not. This 2033 * increased flexibility in the virtual machine can be used to 2034 * implement various language features. For example, covariant 2035 * returns can be implemented with {@linkplain 2036 * java.lang.reflect.Method#isBridge bridge methods}; the bridge 2037 * method and the overriding method would have the same 2038 * signature but different return types. 2039 * 2040 * @return the array of {@code Method} objects representing the 2041 * public methods of this class 2042 * @throws SecurityException 2043 * If a security manager, <i>s</i>, is present and 2044 * the caller's class loader is not the same as or an 2045 * ancestor of the class loader for the current class and 2046 * invocation of {@link SecurityManager#checkPackageAccess 2047 * s.checkPackageAccess()} denies access to the package 2048 * of this class. 2049 * 2050 * @jls 8.2 Class Members 2051 * @jls 8.4 Method Declarations 2052 * @since 1.1 2053 */ 2054 @CallerSensitive 2055 public Method[] getMethods() throws SecurityException { 2056 @SuppressWarnings("removal") 2057 SecurityManager sm = System.getSecurityManager(); 2058 if (sm != null) { 2059 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true); 2060 } 2061 return copyMethods(privateGetPublicMethods()); 2062 } 2063 2064 2065 /** 2066 * Returns an array containing {@code Constructor} objects reflecting 2067 * all the public constructors of the class represented by this 2068 * {@code Class} object. An array of length 0 is returned if the 2069 * class has no public constructors, or if the class is an array class, or 2070 * if the class reflects a primitive type or void. 2071 * 2072 * @apiNote 2073 * While this method returns an array of {@code 2074 * Constructor<T>} objects (that is an array of constructors from 2075 * this class), the return type of this method is {@code 2076 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as 2077 * might be expected. This less informative return type is 2078 * necessary since after being returned from this method, the 2079 * array could be modified to hold {@code Constructor} objects for 2080 * different classes, which would violate the type guarantees of 2081 * {@code Constructor<T>[]}. 2082 * 2083 * @return the array of {@code Constructor} objects representing the 2084 * public constructors of this class 2085 * @throws SecurityException 2086 * If a security manager, <i>s</i>, is present and 2087 * the caller's class loader is not the same as or an 2088 * ancestor of the class loader for the current class and 2089 * invocation of {@link SecurityManager#checkPackageAccess 2090 * s.checkPackageAccess()} denies access to the package 2091 * of this class. 2092 * 2093 * @see #getDeclaredConstructors() 2094 * @since 1.1 2095 */ 2096 @CallerSensitive 2097 public Constructor<?>[] getConstructors() throws SecurityException { 2098 @SuppressWarnings("removal") 2099 SecurityManager sm = System.getSecurityManager(); 2100 if (sm != null) { 2101 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true); 2102 } 2103 return copyConstructors(privateGetDeclaredConstructors(true)); 2104 } 2105 2106 2107 /** 2108 * Returns a {@code Field} object that reflects the specified public member 2109 * field of the class or interface represented by this {@code Class} 2110 * object. The {@code name} parameter is a {@code String} specifying the 2111 * simple name of the desired field. 2112 * 2113 * <p> The field to be reflected is determined by the algorithm that 2114 * follows. Let C be the class or interface represented by this {@code Class} object: 2115 * 2116 * <OL> 2117 * <LI> If C declares a public field with the name specified, that is the 2118 * field to be reflected.</LI> 2119 * <LI> If no field was found in step 1 above, this algorithm is applied 2120 * recursively to each direct superinterface of C. The direct 2121 * superinterfaces are searched in the order they were declared.</LI> 2122 * <LI> If no field was found in steps 1 and 2 above, and C has a 2123 * superclass S, then this algorithm is invoked recursively upon S. 2124 * If C has no superclass, then a {@code NoSuchFieldException} 2125 * is thrown.</LI> 2126 * </OL> 2127 * 2128 * <p> If this {@code Class} object represents an array type, then this 2129 * method does not find the {@code length} field of the array type. 2130 * 2131 * @param name the field name 2132 * @return the {@code Field} object of this class specified by 2133 * {@code name} 2134 * @throws NoSuchFieldException if a field with the specified name is 2135 * not found. 2136 * @throws NullPointerException if {@code name} is {@code null} 2137 * @throws SecurityException 2138 * If a security manager, <i>s</i>, is present and 2139 * the caller's class loader is not the same as or an 2140 * ancestor of the class loader for the current class and 2141 * invocation of {@link SecurityManager#checkPackageAccess 2142 * s.checkPackageAccess()} denies access to the package 2143 * of this class. 2144 * 2145 * @since 1.1 2146 * @jls 8.2 Class Members 2147 * @jls 8.3 Field Declarations 2148 */ 2149 @CallerSensitive 2150 public Field getField(String name) 2151 throws NoSuchFieldException, SecurityException { 2152 Objects.requireNonNull(name); 2153 @SuppressWarnings("removal") 2154 SecurityManager sm = System.getSecurityManager(); 2155 if (sm != null) { 2156 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true); 2157 } 2158 Field field = getField0(name); 2159 if (field == null) { 2160 throw new NoSuchFieldException(name); 2161 } 2162 return getReflectionFactory().copyField(field); 2163 } 2164 2165 2166 /** 2167 * Returns a {@code Method} object that reflects the specified public 2168 * member method of the class or interface represented by this 2169 * {@code Class} object. The {@code name} parameter is a 2170 * {@code String} specifying the simple name of the desired method. The 2171 * {@code parameterTypes} parameter is an array of {@code Class} 2172 * objects that identify the method's formal parameter types, in declared 2173 * order. If {@code parameterTypes} is {@code null}, it is 2174 * treated as if it were an empty array. 2175 * 2176 * <p> If this {@code Class} object represents an array type, then this 2177 * method finds any public method inherited by the array type from 2178 * {@code Object} except method {@code clone()}. 2179 * 2180 * <p> If this {@code Class} object represents an interface then this 2181 * method does not find any implicitly declared method from 2182 * {@code Object}. Therefore, if no methods are explicitly declared in 2183 * this interface or any of its superinterfaces, then this method does not 2184 * find any method. 2185 * 2186 * <p> This method does not find any method with name "{@code <init>}" or 2187 * "{@code <clinit>}". 2188 * 2189 * <p> Generally, the method to be reflected is determined by the 4 step 2190 * algorithm that follows. 2191 * Let C be the class or interface represented by this {@code Class} object: 2192 * <ol> 2193 * <li> A union of methods is composed of: 2194 * <ol type="a"> 2195 * <li> C's declared public instance and static methods as returned by 2196 * {@link #getDeclaredMethods()} and filtered to include only public 2197 * methods that match given {@code name} and {@code parameterTypes}</li> 2198 * <li> If C is a class other than {@code Object}, then include the result 2199 * of invoking this algorithm recursively on the superclass of C.</li> 2200 * <li> Include the results of invoking this algorithm recursively on all 2201 * direct superinterfaces of C, but include only instance methods.</li> 2202 * </ol></li> 2203 * <li> This union is partitioned into subsets of methods with same 2204 * return type (the selection of methods from step 1 also guarantees that 2205 * they have the same method name and parameter types).</li> 2206 * <li> Within each such subset only the most specific methods are selected. 2207 * Let method M be a method from a set of methods with same VM 2208 * signature (return type, name, parameter types). 2209 * M is most specific if there is no such method N != M from the same 2210 * set, such that N is more specific than M. N is more specific than M 2211 * if: 2212 * <ol type="a"> 2213 * <li> N is declared by a class and M is declared by an interface; or</li> 2214 * <li> N and M are both declared by classes or both by interfaces and 2215 * N's declaring type is the same as or a subtype of M's declaring type 2216 * (clearly, if M's and N's declaring types are the same type, then 2217 * M and N are the same method).</li> 2218 * </ol></li> 2219 * <li> The result of this algorithm is chosen arbitrarily from the methods 2220 * with most specific return type among all selected methods from step 3. 2221 * Let R be a return type of a method M from the set of all selected methods 2222 * from step 3. M is a method with most specific return type if there is 2223 * no such method N != M from the same set, having return type S != R, 2224 * such that S is a subtype of R as determined by 2225 * R.class.{@link #isAssignableFrom}(S.class). 2226 * </ol> 2227 * 2228 * @apiNote There may be more than one method with matching name and 2229 * parameter types in a class because while the Java language forbids a 2230 * class to declare multiple methods with the same signature but different 2231 * return types, the Java virtual machine does not. This 2232 * increased flexibility in the virtual machine can be used to 2233 * implement various language features. For example, covariant 2234 * returns can be implemented with {@linkplain 2235 * java.lang.reflect.Method#isBridge bridge methods}; the bridge 2236 * method and the overriding method would have the same 2237 * signature but different return types. This method would return the 2238 * overriding method as it would have a more specific return type. 2239 * 2240 * @param name the name of the method 2241 * @param parameterTypes the list of parameters 2242 * @return the {@code Method} object that matches the specified 2243 * {@code name} and {@code parameterTypes} 2244 * @throws NoSuchMethodException if a matching method is not found 2245 * or if the name is "<init>"or "<clinit>". 2246 * @throws NullPointerException if {@code name} is {@code null} 2247 * @throws SecurityException 2248 * If a security manager, <i>s</i>, is present and 2249 * the caller's class loader is not the same as or an 2250 * ancestor of the class loader for the current class and 2251 * invocation of {@link SecurityManager#checkPackageAccess 2252 * s.checkPackageAccess()} denies access to the package 2253 * of this class. 2254 * 2255 * @jls 8.2 Class Members 2256 * @jls 8.4 Method Declarations 2257 * @since 1.1 2258 */ 2259 @CallerSensitive 2260 public Method getMethod(String name, Class<?>... parameterTypes) 2261 throws NoSuchMethodException, SecurityException { 2262 Objects.requireNonNull(name); 2263 @SuppressWarnings("removal") 2264 SecurityManager sm = System.getSecurityManager(); 2265 if (sm != null) { 2266 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true); 2267 } 2268 Method method = getMethod0(name, parameterTypes); 2269 if (method == null) { 2270 throw new NoSuchMethodException(methodToString(name, parameterTypes)); 2271 } 2272 return getReflectionFactory().copyMethod(method); 2273 } 2274 2275 /** 2276 * Returns a {@code Constructor} object that reflects the specified 2277 * public constructor of the class represented by this {@code Class} 2278 * object. The {@code parameterTypes} parameter is an array of 2279 * {@code Class} objects that identify the constructor's formal 2280 * parameter types, in declared order. 2281 * 2282 * If this {@code Class} object represents an inner class 2283 * declared in a non-static context, the formal parameter types 2284 * include the explicit enclosing instance as the first parameter. 2285 * 2286 * <p> The constructor to reflect is the public constructor of the class 2287 * represented by this {@code Class} object whose formal parameter 2288 * types match those specified by {@code parameterTypes}. 2289 * 2290 * @param parameterTypes the parameter array 2291 * @return the {@code Constructor} object of the public constructor that 2292 * matches the specified {@code parameterTypes} 2293 * @throws NoSuchMethodException if a matching constructor is not found, 2294 * including when this {@code Class} object represents 2295 * an interface, a primitive type, an array class, or void. 2296 * @throws SecurityException 2297 * If a security manager, <i>s</i>, is present and 2298 * the caller's class loader is not the same as or an 2299 * ancestor of the class loader for the current class and 2300 * invocation of {@link SecurityManager#checkPackageAccess 2301 * s.checkPackageAccess()} denies access to the package 2302 * of this class. 2303 * 2304 * @see #getDeclaredConstructor(Class<?>[]) 2305 * @since 1.1 2306 */ 2307 @CallerSensitive 2308 public Constructor<T> getConstructor(Class<?>... parameterTypes) 2309 throws NoSuchMethodException, SecurityException 2310 { 2311 @SuppressWarnings("removal") 2312 SecurityManager sm = System.getSecurityManager(); 2313 if (sm != null) { 2314 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true); 2315 } 2316 return getReflectionFactory().copyConstructor( 2317 getConstructor0(parameterTypes, Member.PUBLIC)); 2318 } 2319 2320 2321 /** 2322 * Returns an array of {@code Class} objects reflecting all the 2323 * classes and interfaces declared as members of the class represented by 2324 * this {@code Class} object. This includes public, protected, default 2325 * (package) access, and private classes and interfaces declared by the 2326 * class, but excludes inherited classes and interfaces. This method 2327 * returns an array of length 0 if the class declares no classes or 2328 * interfaces as members, or if this {@code Class} object represents a 2329 * primitive type, an array class, or void. 2330 * 2331 * @return the array of {@code Class} objects representing all the 2332 * declared members of this class 2333 * @throws SecurityException 2334 * If a security manager, <i>s</i>, is present and any of the 2335 * following conditions is met: 2336 * 2337 * <ul> 2338 * 2339 * <li> the caller's class loader is not the same as the 2340 * class loader of this class and invocation of 2341 * {@link SecurityManager#checkPermission 2342 * s.checkPermission} method with 2343 * {@code RuntimePermission("accessDeclaredMembers")} 2344 * denies access to the declared classes within this class 2345 * 2346 * <li> the caller's class loader is not the same as or an 2347 * ancestor of the class loader for the current class and 2348 * invocation of {@link SecurityManager#checkPackageAccess 2349 * s.checkPackageAccess()} denies access to the package 2350 * of this class 2351 * 2352 * </ul> 2353 * 2354 * @since 1.1 2355 * @jls 8.5 Member Type Declarations 2356 */ 2357 @CallerSensitive 2358 public Class<?>[] getDeclaredClasses() throws SecurityException { 2359 @SuppressWarnings("removal") 2360 SecurityManager sm = System.getSecurityManager(); 2361 if (sm != null) { 2362 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), false); 2363 } 2364 return getDeclaredClasses0(); 2365 } 2366 2367 2368 /** 2369 * Returns an array of {@code Field} objects reflecting all the fields 2370 * declared by the class or interface represented by this 2371 * {@code Class} object. This includes public, protected, default 2372 * (package) access, and private fields, but excludes inherited fields. 2373 * 2374 * <p> If this {@code Class} object represents a class or interface with no 2375 * declared fields, then this method returns an array of length 0. 2376 * 2377 * <p> If this {@code Class} object represents an array type, a primitive 2378 * type, or void, then this method returns an array of length 0. 2379 * 2380 * <p> The elements in the returned array are not sorted and are not in any 2381 * particular order. 2382 * 2383 * @return the array of {@code Field} objects representing all the 2384 * declared fields of this class 2385 * @throws SecurityException 2386 * If a security manager, <i>s</i>, is present and any of the 2387 * following conditions is met: 2388 * 2389 * <ul> 2390 * 2391 * <li> the caller's class loader is not the same as the 2392 * class loader of this class and invocation of 2393 * {@link SecurityManager#checkPermission 2394 * s.checkPermission} method with 2395 * {@code RuntimePermission("accessDeclaredMembers")} 2396 * denies access to the declared fields within this class 2397 * 2398 * <li> the caller's class loader is not the same as or an 2399 * ancestor of the class loader for the current class and 2400 * invocation of {@link SecurityManager#checkPackageAccess 2401 * s.checkPackageAccess()} denies access to the package 2402 * of this class 2403 * 2404 * </ul> 2405 * 2406 * @since 1.1 2407 * @jls 8.2 Class Members 2408 * @jls 8.3 Field Declarations 2409 */ 2410 @CallerSensitive 2411 public Field[] getDeclaredFields() throws SecurityException { 2412 @SuppressWarnings("removal") 2413 SecurityManager sm = System.getSecurityManager(); 2414 if (sm != null) { 2415 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true); 2416 } 2417 return copyFields(privateGetDeclaredFields(false)); 2418 } 2419 2420 /** 2421 * Returns an array of {@code RecordComponent} objects representing all the 2422 * record components of this record class, or {@code null} if this class is 2423 * not a record class. 2424 * 2425 * <p> The components are returned in the same order that they are declared 2426 * in the record header. The array is empty if this record class has no 2427 * components. If the class is not a record class, that is {@link 2428 * #isRecord()} returns {@code false}, then this method returns {@code null}. 2429 * Conversely, if {@link #isRecord()} returns {@code true}, then this method 2430 * returns a non-null value. 2431 * 2432 * @apiNote 2433 * <p> The following method can be used to find the record canonical constructor: 2434 * 2435 * <pre>{@code 2436 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls) 2437 * throws NoSuchMethodException { 2438 * Class<?>[] paramTypes = 2439 * Arrays.stream(cls.getRecordComponents()) 2440 * .map(RecordComponent::getType) 2441 * .toArray(Class<?>[]::new); 2442 * return cls.getDeclaredConstructor(paramTypes); 2443 * }}</pre> 2444 * 2445 * @return An array of {@code RecordComponent} objects representing all the 2446 * record components of this record class, or {@code null} if this 2447 * class is not a record class 2448 * @throws SecurityException 2449 * If a security manager, <i>s</i>, is present and any of the 2450 * following conditions is met: 2451 * 2452 * <ul> 2453 * 2454 * <li> the caller's class loader is not the same as the 2455 * class loader of this class and invocation of 2456 * {@link SecurityManager#checkPermission 2457 * s.checkPermission} method with 2458 * {@code RuntimePermission("accessDeclaredMembers")} 2459 * denies access to the declared methods within this class 2460 * 2461 * <li> the caller's class loader is not the same as or an 2462 * ancestor of the class loader for the current class and 2463 * invocation of {@link SecurityManager#checkPackageAccess 2464 * s.checkPackageAccess()} denies access to the package 2465 * of this class 2466 * 2467 * </ul> 2468 * 2469 * @jls 8.10 Record Classes 2470 * @since 16 2471 */ 2472 @CallerSensitive 2473 public RecordComponent[] getRecordComponents() { 2474 @SuppressWarnings("removal") 2475 SecurityManager sm = System.getSecurityManager(); 2476 if (sm != null) { 2477 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true); 2478 } 2479 if (!isRecord()) { 2480 return null; 2481 } 2482 return getRecordComponents0(); 2483 } 2484 2485 /** 2486 * Returns an array containing {@code Method} objects reflecting all the 2487 * declared methods of the class or interface represented by this {@code 2488 * Class} object, including public, protected, default (package) 2489 * access, and private methods, but excluding inherited methods. 2490 * The declared methods may include methods <em>not</em> in the 2491 * source of the class or interface, including {@linkplain 2492 * Method#isBridge bridge methods} and other {@linkplain 2493 * Executable#isSynthetic synthetic} methods added by compilers. 2494 * 2495 * <p> If this {@code Class} object represents a class or interface that 2496 * has multiple declared methods with the same name and parameter types, 2497 * but different return types, then the returned array has a {@code Method} 2498 * object for each such method. 2499 * 2500 * <p> If this {@code Class} object represents a class or interface that 2501 * has a class initialization method {@code <clinit>}, then the returned 2502 * array does <em>not</em> have a corresponding {@code Method} object. 2503 * 2504 * <p> If this {@code Class} object represents a class or interface with no 2505 * declared methods, then the returned array has length 0. 2506 * 2507 * <p> If this {@code Class} object represents an array type, a primitive 2508 * type, or void, then the returned array has length 0. 2509 * 2510 * <p> The elements in the returned array are not sorted and are not in any 2511 * particular order. 2512 * 2513 * @return the array of {@code Method} objects representing all the 2514 * declared methods of this class 2515 * @throws SecurityException 2516 * If a security manager, <i>s</i>, is present and any of the 2517 * following conditions is met: 2518 * 2519 * <ul> 2520 * 2521 * <li> the caller's class loader is not the same as the 2522 * class loader of this class and invocation of 2523 * {@link SecurityManager#checkPermission 2524 * s.checkPermission} method with 2525 * {@code RuntimePermission("accessDeclaredMembers")} 2526 * denies access to the declared methods within this class 2527 * 2528 * <li> the caller's class loader is not the same as or an 2529 * ancestor of the class loader for the current class and 2530 * invocation of {@link SecurityManager#checkPackageAccess 2531 * s.checkPackageAccess()} denies access to the package 2532 * of this class 2533 * 2534 * </ul> 2535 * 2536 * @jls 8.2 Class Members 2537 * @jls 8.4 Method Declarations 2538 * @see <a 2539 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java 2540 * programming language and JVM modeling in core reflection</a> 2541 * @since 1.1 2542 */ 2543 @CallerSensitive 2544 public Method[] getDeclaredMethods() throws SecurityException { 2545 @SuppressWarnings("removal") 2546 SecurityManager sm = System.getSecurityManager(); 2547 if (sm != null) { 2548 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true); 2549 } 2550 return copyMethods(privateGetDeclaredMethods(false)); 2551 } 2552 2553 /** 2554 * Returns an array of {@code Constructor} objects reflecting all the 2555 * constructors implicitly or explicitly declared by the class represented by this 2556 * {@code Class} object. These are public, protected, default 2557 * (package) access, and private constructors. The elements in the array 2558 * returned are not sorted and are not in any particular order. If the 2559 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array. 2560 * If a record class has a canonical constructor (JLS {@jls 2561 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array. 2562 * 2563 * This method returns an array of length 0 if this {@code Class} 2564 * object represents an interface, a primitive type, an array class, or 2565 * void. 2566 * 2567 * @return the array of {@code Constructor} objects representing all the 2568 * declared constructors of this class 2569 * @throws SecurityException 2570 * If a security manager, <i>s</i>, is present and any of the 2571 * following conditions is met: 2572 * 2573 * <ul> 2574 * 2575 * <li> the caller's class loader is not the same as the 2576 * class loader of this class and invocation of 2577 * {@link SecurityManager#checkPermission 2578 * s.checkPermission} method with 2579 * {@code RuntimePermission("accessDeclaredMembers")} 2580 * denies access to the declared constructors within this class 2581 * 2582 * <li> the caller's class loader is not the same as or an 2583 * ancestor of the class loader for the current class and 2584 * invocation of {@link SecurityManager#checkPackageAccess 2585 * s.checkPackageAccess()} denies access to the package 2586 * of this class 2587 * 2588 * </ul> 2589 * 2590 * @since 1.1 2591 * @see #getConstructors() 2592 * @jls 8.8 Constructor Declarations 2593 */ 2594 @CallerSensitive 2595 public Constructor<?>[] getDeclaredConstructors() throws SecurityException { 2596 @SuppressWarnings("removal") 2597 SecurityManager sm = System.getSecurityManager(); 2598 if (sm != null) { 2599 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true); 2600 } 2601 return copyConstructors(privateGetDeclaredConstructors(false)); 2602 } 2603 2604 2605 /** 2606 * Returns a {@code Field} object that reflects the specified declared 2607 * field of the class or interface represented by this {@code Class} 2608 * object. The {@code name} parameter is a {@code String} that specifies 2609 * the simple name of the desired field. 2610 * 2611 * <p> If this {@code Class} object represents an array type, then this 2612 * method does not find the {@code length} field of the array type. 2613 * 2614 * @param name the name of the field 2615 * @return the {@code Field} object for the specified field in this 2616 * class 2617 * @throws NoSuchFieldException if a field with the specified name is 2618 * not found. 2619 * @throws NullPointerException if {@code name} is {@code null} 2620 * @throws SecurityException 2621 * If a security manager, <i>s</i>, is present and any of the 2622 * following conditions is met: 2623 * 2624 * <ul> 2625 * 2626 * <li> the caller's class loader is not the same as the 2627 * class loader of this class and invocation of 2628 * {@link SecurityManager#checkPermission 2629 * s.checkPermission} method with 2630 * {@code RuntimePermission("accessDeclaredMembers")} 2631 * denies access to the declared field 2632 * 2633 * <li> the caller's class loader is not the same as or an 2634 * ancestor of the class loader for the current class and 2635 * invocation of {@link SecurityManager#checkPackageAccess 2636 * s.checkPackageAccess()} denies access to the package 2637 * of this class 2638 * 2639 * </ul> 2640 * 2641 * @since 1.1 2642 * @jls 8.2 Class Members 2643 * @jls 8.3 Field Declarations 2644 */ 2645 @CallerSensitive 2646 public Field getDeclaredField(String name) 2647 throws NoSuchFieldException, SecurityException { 2648 Objects.requireNonNull(name); 2649 @SuppressWarnings("removal") 2650 SecurityManager sm = System.getSecurityManager(); 2651 if (sm != null) { 2652 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true); 2653 } 2654 Field field = searchFields(privateGetDeclaredFields(false), name); 2655 if (field == null) { 2656 throw new NoSuchFieldException(name); 2657 } 2658 return getReflectionFactory().copyField(field); 2659 } 2660 2661 2662 /** 2663 * Returns a {@code Method} object that reflects the specified 2664 * declared method of the class or interface represented by this 2665 * {@code Class} object. The {@code name} parameter is a 2666 * {@code String} that specifies the simple name of the desired 2667 * method, and the {@code parameterTypes} parameter is an array of 2668 * {@code Class} objects that identify the method's formal parameter 2669 * types, in declared order. If more than one method with the same 2670 * parameter types is declared in a class, and one of these methods has a 2671 * return type that is more specific than any of the others, that method is 2672 * returned; otherwise one of the methods is chosen arbitrarily. If the 2673 * name is "<init>"or "<clinit>" a {@code NoSuchMethodException} 2674 * is raised. 2675 * 2676 * <p> If this {@code Class} object represents an array type, then this 2677 * method does not find the {@code clone()} method. 2678 * 2679 * @param name the name of the method 2680 * @param parameterTypes the parameter array 2681 * @return the {@code Method} object for the method of this class 2682 * matching the specified name and parameters 2683 * @throws NoSuchMethodException if a matching method is not found. 2684 * @throws NullPointerException if {@code name} is {@code null} 2685 * @throws SecurityException 2686 * If a security manager, <i>s</i>, is present and any of the 2687 * following conditions is met: 2688 * 2689 * <ul> 2690 * 2691 * <li> the caller's class loader is not the same as the 2692 * class loader of this class and invocation of 2693 * {@link SecurityManager#checkPermission 2694 * s.checkPermission} method with 2695 * {@code RuntimePermission("accessDeclaredMembers")} 2696 * denies access to the declared method 2697 * 2698 * <li> the caller's class loader is not the same as or an 2699 * ancestor of the class loader for the current class and 2700 * invocation of {@link SecurityManager#checkPackageAccess 2701 * s.checkPackageAccess()} denies access to the package 2702 * of this class 2703 * 2704 * </ul> 2705 * 2706 * @jls 8.2 Class Members 2707 * @jls 8.4 Method Declarations 2708 * @since 1.1 2709 */ 2710 @CallerSensitive 2711 public Method getDeclaredMethod(String name, Class<?>... parameterTypes) 2712 throws NoSuchMethodException, SecurityException { 2713 Objects.requireNonNull(name); 2714 @SuppressWarnings("removal") 2715 SecurityManager sm = System.getSecurityManager(); 2716 if (sm != null) { 2717 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true); 2718 } 2719 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes); 2720 if (method == null) { 2721 throw new NoSuchMethodException(methodToString(name, parameterTypes)); 2722 } 2723 return getReflectionFactory().copyMethod(method); 2724 } 2725 2726 /** 2727 * Returns the list of {@code Method} objects for the declared public 2728 * methods of this class or interface that have the specified method name 2729 * and parameter types. 2730 * 2731 * @param name the name of the method 2732 * @param parameterTypes the parameter array 2733 * @return the list of {@code Method} objects for the public methods of 2734 * this class matching the specified name and parameters 2735 */ 2736 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) { 2737 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true); 2738 ReflectionFactory factory = getReflectionFactory(); 2739 List<Method> result = new ArrayList<>(); 2740 for (Method method : methods) { 2741 if (method.getName().equals(name) 2742 && Arrays.equals( 2743 factory.getExecutableSharedParameterTypes(method), 2744 parameterTypes)) { 2745 result.add(factory.copyMethod(method)); 2746 } 2747 } 2748 return result; 2749 } 2750 2751 /** 2752 * Returns a {@code Constructor} object that reflects the specified 2753 * constructor of the class represented by this 2754 * {@code Class} object. The {@code parameterTypes} parameter is 2755 * an array of {@code Class} objects that identify the constructor's 2756 * formal parameter types, in declared order. 2757 * 2758 * If this {@code Class} object represents an inner class 2759 * declared in a non-static context, the formal parameter types 2760 * include the explicit enclosing instance as the first parameter. 2761 * 2762 * @param parameterTypes the parameter array 2763 * @return The {@code Constructor} object for the constructor with the 2764 * specified parameter list 2765 * @throws NoSuchMethodException if a matching constructor is not found, 2766 * including when this {@code Class} object represents 2767 * an interface, a primitive type, an array class, or void. 2768 * @throws SecurityException 2769 * If a security manager, <i>s</i>, is present and any of the 2770 * following conditions is met: 2771 * 2772 * <ul> 2773 * 2774 * <li> the caller's class loader is not the same as the 2775 * class loader of this class and invocation of 2776 * {@link SecurityManager#checkPermission 2777 * s.checkPermission} method with 2778 * {@code RuntimePermission("accessDeclaredMembers")} 2779 * denies access to the declared constructor 2780 * 2781 * <li> the caller's class loader is not the same as or an 2782 * ancestor of the class loader for the current class and 2783 * invocation of {@link SecurityManager#checkPackageAccess 2784 * s.checkPackageAccess()} denies access to the package 2785 * of this class 2786 * 2787 * </ul> 2788 * 2789 * @see #getConstructor(Class<?>[]) 2790 * @since 1.1 2791 */ 2792 @CallerSensitive 2793 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes) 2794 throws NoSuchMethodException, SecurityException 2795 { 2796 @SuppressWarnings("removal") 2797 SecurityManager sm = System.getSecurityManager(); 2798 if (sm != null) { 2799 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true); 2800 } 2801 2802 return getReflectionFactory().copyConstructor( 2803 getConstructor0(parameterTypes, Member.DECLARED)); 2804 } 2805 2806 /** 2807 * Finds a resource with a given name. 2808 * 2809 * <p> If this class is in a named {@link Module Module} then this method 2810 * will attempt to find the resource in the module. This is done by 2811 * delegating to the module's class loader {@link 2812 * ClassLoader#findResource(String,String) findResource(String,String)} 2813 * method, invoking it with the module name and the absolute name of the 2814 * resource. Resources in named modules are subject to the rules for 2815 * encapsulation specified in the {@code Module} {@link 2816 * Module#getResourceAsStream getResourceAsStream} method and so this 2817 * method returns {@code null} when the resource is a 2818 * non-"{@code .class}" resource in a package that is not open to the 2819 * caller's module. 2820 * 2821 * <p> Otherwise, if this class is not in a named module then the rules for 2822 * searching resources associated with a given class are implemented by the 2823 * defining {@linkplain ClassLoader class loader} of the class. This method 2824 * delegates to this {@code Class} object's class loader. 2825 * If this {@code Class} object was loaded by the bootstrap class loader, 2826 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}. 2827 * 2828 * <p> Before delegation, an absolute resource name is constructed from the 2829 * given resource name using this algorithm: 2830 * 2831 * <ul> 2832 * 2833 * <li> If the {@code name} begins with a {@code '/'} 2834 * (<code>'\u002f'</code>), then the absolute name of the resource is the 2835 * portion of the {@code name} following the {@code '/'}. 2836 * 2837 * <li> Otherwise, the absolute name is of the following form: 2838 * 2839 * <blockquote> 2840 * {@code modified_package_name/name} 2841 * </blockquote> 2842 * 2843 * <p> Where the {@code modified_package_name} is the package name of this 2844 * object with {@code '/'} substituted for {@code '.'} 2845 * (<code>'\u002e'</code>). 2846 * 2847 * </ul> 2848 * 2849 * @param name name of the desired resource 2850 * @return A {@link java.io.InputStream} object; {@code null} if no 2851 * resource with this name is found, the resource is in a package 2852 * that is not {@linkplain Module#isOpen(String, Module) open} to at 2853 * least the caller module, or access to the resource is denied 2854 * by the security manager. 2855 * @throws NullPointerException If {@code name} is {@code null} 2856 * 2857 * @see Module#getResourceAsStream(String) 2858 * @since 1.1 2859 * @revised 9 2860 */ 2861 @CallerSensitive 2862 public InputStream getResourceAsStream(String name) { 2863 name = resolveName(name); 2864 2865 Module thisModule = getModule(); 2866 if (thisModule.isNamed()) { 2867 // check if resource can be located by caller 2868 if (Resources.canEncapsulate(name) 2869 && !isOpenToCaller(name, Reflection.getCallerClass())) { 2870 return null; 2871 } 2872 2873 // resource not encapsulated or in package open to caller 2874 String mn = thisModule.getName(); 2875 ClassLoader cl = classLoader; 2876 try { 2877 2878 // special-case built-in class loaders to avoid the 2879 // need for a URL connection 2880 if (cl == null) { 2881 return BootLoader.findResourceAsStream(mn, name); 2882 } else if (cl instanceof BuiltinClassLoader) { 2883 return ((BuiltinClassLoader) cl).findResourceAsStream(mn, name); 2884 } else { 2885 URL url = cl.findResource(mn, name); 2886 return (url != null) ? url.openStream() : null; 2887 } 2888 2889 } catch (IOException | SecurityException e) { 2890 return null; 2891 } 2892 } 2893 2894 // unnamed module 2895 ClassLoader cl = classLoader; 2896 if (cl == null) { 2897 return ClassLoader.getSystemResourceAsStream(name); 2898 } else { 2899 return cl.getResourceAsStream(name); 2900 } 2901 } 2902 2903 /** 2904 * Finds a resource with a given name. 2905 * 2906 * <p> If this class is in a named {@link Module Module} then this method 2907 * will attempt to find the resource in the module. This is done by 2908 * delegating to the module's class loader {@link 2909 * ClassLoader#findResource(String,String) findResource(String,String)} 2910 * method, invoking it with the module name and the absolute name of the 2911 * resource. Resources in named modules are subject to the rules for 2912 * encapsulation specified in the {@code Module} {@link 2913 * Module#getResourceAsStream getResourceAsStream} method and so this 2914 * method returns {@code null} when the resource is a 2915 * non-"{@code .class}" resource in a package that is not open to the 2916 * caller's module. 2917 * 2918 * <p> Otherwise, if this class is not in a named module then the rules for 2919 * searching resources associated with a given class are implemented by the 2920 * defining {@linkplain ClassLoader class loader} of the class. This method 2921 * delegates to this {@code Class} object's class loader. 2922 * If this {@code Class} object was loaded by the bootstrap class loader, 2923 * the method delegates to {@link ClassLoader#getSystemResource}. 2924 * 2925 * <p> Before delegation, an absolute resource name is constructed from the 2926 * given resource name using this algorithm: 2927 * 2928 * <ul> 2929 * 2930 * <li> If the {@code name} begins with a {@code '/'} 2931 * (<code>'\u002f'</code>), then the absolute name of the resource is the 2932 * portion of the {@code name} following the {@code '/'}. 2933 * 2934 * <li> Otherwise, the absolute name is of the following form: 2935 * 2936 * <blockquote> 2937 * {@code modified_package_name/name} 2938 * </blockquote> 2939 * 2940 * <p> Where the {@code modified_package_name} is the package name of this 2941 * object with {@code '/'} substituted for {@code '.'} 2942 * (<code>'\u002e'</code>). 2943 * 2944 * </ul> 2945 * 2946 * @param name name of the desired resource 2947 * @return A {@link java.net.URL} object; {@code null} if no resource with 2948 * this name is found, the resource cannot be located by a URL, the 2949 * resource is in a package that is not 2950 * {@linkplain Module#isOpen(String, Module) open} to at least the caller 2951 * module, or access to the resource is denied by the security 2952 * manager. 2953 * @throws NullPointerException If {@code name} is {@code null} 2954 * @since 1.1 2955 * @revised 9 2956 */ 2957 @CallerSensitive 2958 public URL getResource(String name) { 2959 name = resolveName(name); 2960 2961 Module thisModule = getModule(); 2962 if (thisModule.isNamed()) { 2963 // check if resource can be located by caller 2964 if (Resources.canEncapsulate(name) 2965 && !isOpenToCaller(name, Reflection.getCallerClass())) { 2966 return null; 2967 } 2968 2969 // resource not encapsulated or in package open to caller 2970 String mn = thisModule.getName(); 2971 ClassLoader cl = classLoader; 2972 try { 2973 if (cl == null) { 2974 return BootLoader.findResource(mn, name); 2975 } else { 2976 return cl.findResource(mn, name); 2977 } 2978 } catch (IOException ioe) { 2979 return null; 2980 } 2981 } 2982 2983 // unnamed module 2984 ClassLoader cl = classLoader; 2985 if (cl == null) { 2986 return ClassLoader.getSystemResource(name); 2987 } else { 2988 return cl.getResource(name); 2989 } 2990 } 2991 2992 /** 2993 * Returns true if a resource with the given name can be located by the 2994 * given caller. All resources in a module can be located by code in 2995 * the module. For other callers, then the package needs to be open to 2996 * the caller. 2997 */ 2998 private boolean isOpenToCaller(String name, Class<?> caller) { 2999 // assert getModule().isNamed(); 3000 Module thisModule = getModule(); 3001 Module callerModule = (caller != null) ? caller.getModule() : null; 3002 if (callerModule != thisModule) { 3003 String pn = Resources.toPackageName(name); 3004 if (thisModule.getDescriptor().packages().contains(pn)) { 3005 if (callerModule == null && !thisModule.isOpen(pn)) { 3006 // no caller, package not open 3007 return false; 3008 } 3009 if (!thisModule.isOpen(pn, callerModule)) { 3010 // package not open to caller 3011 return false; 3012 } 3013 } 3014 } 3015 return true; 3016 } 3017 3018 3019 /** protection domain returned when the internal domain is null */ 3020 private static java.security.ProtectionDomain allPermDomain; 3021 3022 /** 3023 * Returns the {@code ProtectionDomain} of this class. If there is a 3024 * security manager installed, this method first calls the security 3025 * manager's {@code checkPermission} method with a 3026 * {@code RuntimePermission("getProtectionDomain")} permission to 3027 * ensure it's ok to get the 3028 * {@code ProtectionDomain}. 3029 * 3030 * @return the ProtectionDomain of this class 3031 * 3032 * @throws SecurityException 3033 * if a security manager exists and its 3034 * {@code checkPermission} method doesn't allow 3035 * getting the ProtectionDomain. 3036 * 3037 * @see java.security.ProtectionDomain 3038 * @see SecurityManager#checkPermission 3039 * @see java.lang.RuntimePermission 3040 * @since 1.2 3041 */ 3042 public java.security.ProtectionDomain getProtectionDomain() { 3043 @SuppressWarnings("removal") 3044 SecurityManager sm = System.getSecurityManager(); 3045 if (sm != null) { 3046 sm.checkPermission(SecurityConstants.GET_PD_PERMISSION); 3047 } 3048 return protectionDomain(); 3049 } 3050 3051 // package-private 3052 java.security.ProtectionDomain protectionDomain() { 3053 java.security.ProtectionDomain pd = getProtectionDomain0(); 3054 if (pd == null) { 3055 if (allPermDomain == null) { 3056 java.security.Permissions perms = 3057 new java.security.Permissions(); 3058 perms.add(SecurityConstants.ALL_PERMISSION); 3059 allPermDomain = 3060 new java.security.ProtectionDomain(null, perms); 3061 } 3062 pd = allPermDomain; 3063 } 3064 return pd; 3065 } 3066 3067 /** 3068 * Returns the ProtectionDomain of this class. 3069 */ 3070 private native java.security.ProtectionDomain getProtectionDomain0(); 3071 3072 /* 3073 * Return the Virtual Machine's Class object for the named 3074 * primitive type. 3075 */ 3076 static native Class<?> getPrimitiveClass(String name); 3077 3078 /* 3079 * Check if client is allowed to access members. If access is denied, 3080 * throw a SecurityException. 3081 * 3082 * This method also enforces package access. 3083 * 3084 * <p> Default policy: allow all clients access with normal Java access 3085 * control. 3086 * 3087 * <p> NOTE: should only be called if a SecurityManager is installed 3088 */ 3089 private void checkMemberAccess(@SuppressWarnings("removal") SecurityManager sm, int which, 3090 Class<?> caller, boolean checkProxyInterfaces) { 3091 /* Default policy allows access to all {@link Member#PUBLIC} members, 3092 * as well as access to classes that have the same class loader as the caller. 3093 * In all other cases, it requires RuntimePermission("accessDeclaredMembers") 3094 * permission. 3095 */ 3096 final ClassLoader ccl = ClassLoader.getClassLoader(caller); 3097 if (which != Member.PUBLIC) { 3098 final ClassLoader cl = classLoader; 3099 if (ccl != cl) { 3100 sm.checkPermission(SecurityConstants.CHECK_MEMBER_ACCESS_PERMISSION); 3101 } 3102 } 3103 this.checkPackageAccess(sm, ccl, checkProxyInterfaces); 3104 } 3105 3106 /* 3107 * Checks if a client loaded in ClassLoader ccl is allowed to access this 3108 * class under the current package access policy. If access is denied, 3109 * throw a SecurityException. 3110 * 3111 * NOTE: this method should only be called if a SecurityManager is active 3112 */ 3113 private void checkPackageAccess(@SuppressWarnings("removal") SecurityManager sm, final ClassLoader ccl, 3114 boolean checkProxyInterfaces) { 3115 final ClassLoader cl = classLoader; 3116 3117 if (ReflectUtil.needsPackageAccessCheck(ccl, cl)) { 3118 String pkg = this.getPackageName(); 3119 if (!pkg.isEmpty()) { 3120 // skip the package access check on a proxy class in default proxy package 3121 if (!Proxy.isProxyClass(this) || ReflectUtil.isNonPublicProxyClass(this)) { 3122 sm.checkPackageAccess(pkg); 3123 } 3124 } 3125 } 3126 // check package access on the proxy interfaces 3127 if (checkProxyInterfaces && Proxy.isProxyClass(this)) { 3128 ReflectUtil.checkProxyPackageAccess(ccl, this.getInterfaces()); 3129 } 3130 } 3131 3132 /* 3133 * Checks if a client loaded in ClassLoader ccl is allowed to access the provided 3134 * classes under the current package access policy. If access is denied, 3135 * throw a SecurityException. 3136 * 3137 * NOTE: this method should only be called if a SecurityManager is active 3138 * classes must be non-empty 3139 * all classes provided must be loaded by the same ClassLoader 3140 * NOTE: this method does not support Proxy classes 3141 */ 3142 private static void checkPackageAccessForPermittedSubclasses(@SuppressWarnings("removal") SecurityManager sm, 3143 final ClassLoader ccl, Class<?>[] subClasses) { 3144 final ClassLoader cl = subClasses[0].classLoader; 3145 3146 if (ReflectUtil.needsPackageAccessCheck(ccl, cl)) { 3147 Set<String> packages = new HashSet<>(); 3148 3149 for (Class<?> c : subClasses) { 3150 if (Proxy.isProxyClass(c)) 3151 throw new InternalError("a permitted subclass should not be a proxy class: " + c); 3152 String pkg = c.getPackageName(); 3153 if (!pkg.isEmpty()) { 3154 packages.add(pkg); 3155 } 3156 } 3157 for (String pkg : packages) { 3158 sm.checkPackageAccess(pkg); 3159 } 3160 } 3161 } 3162 3163 /** 3164 * Add a package name prefix if the name is not absolute. Remove leading "/" 3165 * if name is absolute 3166 */ 3167 private String resolveName(String name) { 3168 if (!name.startsWith("/")) { 3169 String baseName = getPackageName(); 3170 if (!baseName.isEmpty()) { 3171 int len = baseName.length() + 1 + name.length(); 3172 StringBuilder sb = new StringBuilder(len); 3173 name = sb.append(baseName.replace('.', '/')) 3174 .append('/') 3175 .append(name) 3176 .toString(); 3177 } 3178 } else { 3179 name = name.substring(1); 3180 } 3181 return name; 3182 } 3183 3184 /** 3185 * Atomic operations support. 3186 */ 3187 private static class Atomic { 3188 // initialize Unsafe machinery here, since we need to call Class.class instance method 3189 // and have to avoid calling it in the static initializer of the Class class... 3190 private static final Unsafe unsafe = Unsafe.getUnsafe(); 3191 // offset of Class.reflectionData instance field 3192 private static final long reflectionDataOffset 3193 = unsafe.objectFieldOffset(Class.class, "reflectionData"); 3194 // offset of Class.annotationType instance field 3195 private static final long annotationTypeOffset 3196 = unsafe.objectFieldOffset(Class.class, "annotationType"); 3197 // offset of Class.annotationData instance field 3198 private static final long annotationDataOffset 3199 = unsafe.objectFieldOffset(Class.class, "annotationData"); 3200 3201 static <T> boolean casReflectionData(Class<?> clazz, 3202 SoftReference<ReflectionData<T>> oldData, 3203 SoftReference<ReflectionData<T>> newData) { 3204 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData); 3205 } 3206 3207 static boolean casAnnotationType(Class<?> clazz, 3208 AnnotationType oldType, 3209 AnnotationType newType) { 3210 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType); 3211 } 3212 3213 static boolean casAnnotationData(Class<?> clazz, 3214 AnnotationData oldData, 3215 AnnotationData newData) { 3216 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData); 3217 } 3218 } 3219 3220 /** 3221 * Reflection support. 3222 */ 3223 3224 // Reflection data caches various derived names and reflective members. Cached 3225 // values may be invalidated when JVM TI RedefineClasses() is called 3226 private static class ReflectionData<T> { 3227 volatile Field[] declaredFields; 3228 volatile Field[] publicFields; 3229 volatile Method[] declaredMethods; 3230 volatile Method[] publicMethods; 3231 volatile Constructor<T>[] declaredConstructors; 3232 volatile Constructor<T>[] publicConstructors; 3233 // Intermediate results for getFields and getMethods 3234 volatile Field[] declaredPublicFields; 3235 volatile Method[] declaredPublicMethods; 3236 volatile Class<?>[] interfaces; 3237 3238 // Cached names 3239 String simpleName; 3240 String canonicalName; 3241 static final String NULL_SENTINEL = new String(); 3242 3243 // Value of classRedefinedCount when we created this ReflectionData instance 3244 final int redefinedCount; 3245 3246 ReflectionData(int redefinedCount) { 3247 this.redefinedCount = redefinedCount; 3248 } 3249 } 3250 3251 private transient volatile SoftReference<ReflectionData<T>> reflectionData; 3252 3253 // Incremented by the VM on each call to JVM TI RedefineClasses() 3254 // that redefines this class or a superclass. 3255 private transient volatile int classRedefinedCount; 3256 3257 // Lazily create and cache ReflectionData 3258 private ReflectionData<T> reflectionData() { 3259 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData; 3260 int classRedefinedCount = this.classRedefinedCount; 3261 ReflectionData<T> rd; 3262 if (reflectionData != null && 3263 (rd = reflectionData.get()) != null && 3264 rd.redefinedCount == classRedefinedCount) { 3265 return rd; 3266 } 3267 // else no SoftReference or cleared SoftReference or stale ReflectionData 3268 // -> create and replace new instance 3269 return newReflectionData(reflectionData, classRedefinedCount); 3270 } 3271 3272 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData, 3273 int classRedefinedCount) { 3274 while (true) { 3275 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount); 3276 // try to CAS it... 3277 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) { 3278 return rd; 3279 } 3280 // else retry 3281 oldReflectionData = this.reflectionData; 3282 classRedefinedCount = this.classRedefinedCount; 3283 if (oldReflectionData != null && 3284 (rd = oldReflectionData.get()) != null && 3285 rd.redefinedCount == classRedefinedCount) { 3286 return rd; 3287 } 3288 } 3289 } 3290 3291 // Generic signature handling 3292 private native String getGenericSignature0(); 3293 3294 // Generic info repository; lazily initialized 3295 private transient volatile ClassRepository genericInfo; 3296 3297 // accessor for factory 3298 private GenericsFactory getFactory() { 3299 // create scope and factory 3300 return CoreReflectionFactory.make(this, ClassScope.make(this)); 3301 } 3302 3303 // accessor for generic info repository; 3304 // generic info is lazily initialized 3305 private ClassRepository getGenericInfo() { 3306 ClassRepository genericInfo = this.genericInfo; 3307 if (genericInfo == null) { 3308 String signature = getGenericSignature0(); 3309 if (signature == null) { 3310 genericInfo = ClassRepository.NONE; 3311 } else { 3312 genericInfo = ClassRepository.make(signature, getFactory()); 3313 } 3314 this.genericInfo = genericInfo; 3315 } 3316 return (genericInfo != ClassRepository.NONE) ? genericInfo : null; 3317 } 3318 3319 // Annotations handling 3320 native byte[] getRawAnnotations(); 3321 // Since 1.8 3322 native byte[] getRawTypeAnnotations(); 3323 static byte[] getExecutableTypeAnnotationBytes(Executable ex) { 3324 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex); 3325 } 3326 3327 native ConstantPool getConstantPool(); 3328 3329 // 3330 // 3331 // java.lang.reflect.Field handling 3332 // 3333 // 3334 3335 // Returns an array of "root" fields. These Field objects must NOT 3336 // be propagated to the outside world, but must instead be copied 3337 // via ReflectionFactory.copyField. 3338 private Field[] privateGetDeclaredFields(boolean publicOnly) { 3339 Field[] res; 3340 ReflectionData<T> rd = reflectionData(); 3341 if (rd != null) { 3342 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields; 3343 if (res != null) return res; 3344 } 3345 // No cached value available; request value from VM 3346 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly)); 3347 if (rd != null) { 3348 if (publicOnly) { 3349 rd.declaredPublicFields = res; 3350 } else { 3351 rd.declaredFields = res; 3352 } 3353 } 3354 return res; 3355 } 3356 3357 // Returns an array of "root" fields. These Field objects must NOT 3358 // be propagated to the outside world, but must instead be copied 3359 // via ReflectionFactory.copyField. 3360 private Field[] privateGetPublicFields() { 3361 Field[] res; 3362 ReflectionData<T> rd = reflectionData(); 3363 if (rd != null) { 3364 res = rd.publicFields; 3365 if (res != null) return res; 3366 } 3367 3368 // Use a linked hash set to ensure order is preserved and 3369 // fields from common super interfaces are not duplicated 3370 LinkedHashSet<Field> fields = new LinkedHashSet<>(); 3371 3372 // Local fields 3373 addAll(fields, privateGetDeclaredFields(true)); 3374 3375 // Direct superinterfaces, recursively 3376 for (Class<?> si : getInterfaces()) { 3377 addAll(fields, si.privateGetPublicFields()); 3378 } 3379 3380 // Direct superclass, recursively 3381 Class<?> sc = getSuperclass(); 3382 if (sc != null) { 3383 addAll(fields, sc.privateGetPublicFields()); 3384 } 3385 3386 res = fields.toArray(new Field[0]); 3387 if (rd != null) { 3388 rd.publicFields = res; 3389 } 3390 return res; 3391 } 3392 3393 private static void addAll(Collection<Field> c, Field[] o) { 3394 for (Field f : o) { 3395 c.add(f); 3396 } 3397 } 3398 3399 3400 // 3401 // 3402 // java.lang.reflect.Constructor handling 3403 // 3404 // 3405 3406 // Returns an array of "root" constructors. These Constructor 3407 // objects must NOT be propagated to the outside world, but must 3408 // instead be copied via ReflectionFactory.copyConstructor. 3409 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) { 3410 Constructor<T>[] res; 3411 ReflectionData<T> rd = reflectionData(); 3412 if (rd != null) { 3413 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors; 3414 if (res != null) return res; 3415 } 3416 // No cached value available; request value from VM 3417 if (isInterface()) { 3418 @SuppressWarnings("unchecked") 3419 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0]; 3420 res = temporaryRes; 3421 } else { 3422 res = getDeclaredConstructors0(publicOnly); 3423 } 3424 if (rd != null) { 3425 if (publicOnly) { 3426 rd.publicConstructors = res; 3427 } else { 3428 rd.declaredConstructors = res; 3429 } 3430 } 3431 return res; 3432 } 3433 3434 // 3435 // 3436 // java.lang.reflect.Method handling 3437 // 3438 // 3439 3440 // Returns an array of "root" methods. These Method objects must NOT 3441 // be propagated to the outside world, but must instead be copied 3442 // via ReflectionFactory.copyMethod. 3443 private Method[] privateGetDeclaredMethods(boolean publicOnly) { 3444 Method[] res; 3445 ReflectionData<T> rd = reflectionData(); 3446 if (rd != null) { 3447 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods; 3448 if (res != null) return res; 3449 } 3450 // No cached value available; request value from VM 3451 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly)); 3452 if (rd != null) { 3453 if (publicOnly) { 3454 rd.declaredPublicMethods = res; 3455 } else { 3456 rd.declaredMethods = res; 3457 } 3458 } 3459 return res; 3460 } 3461 3462 // Returns an array of "root" methods. These Method objects must NOT 3463 // be propagated to the outside world, but must instead be copied 3464 // via ReflectionFactory.copyMethod. 3465 private Method[] privateGetPublicMethods() { 3466 Method[] res; 3467 ReflectionData<T> rd = reflectionData(); 3468 if (rd != null) { 3469 res = rd.publicMethods; 3470 if (res != null) return res; 3471 } 3472 3473 // No cached value available; compute value recursively. 3474 // Start by fetching public declared methods... 3475 PublicMethods pms = new PublicMethods(); 3476 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) { 3477 pms.merge(m); 3478 } 3479 // ...then recur over superclass methods... 3480 Class<?> sc = getSuperclass(); 3481 if (sc != null) { 3482 for (Method m : sc.privateGetPublicMethods()) { 3483 pms.merge(m); 3484 } 3485 } 3486 // ...and finally over direct superinterfaces. 3487 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) { 3488 for (Method m : intf.privateGetPublicMethods()) { 3489 // static interface methods are not inherited 3490 if (!Modifier.isStatic(m.getModifiers())) { 3491 pms.merge(m); 3492 } 3493 } 3494 } 3495 3496 res = pms.toArray(); 3497 if (rd != null) { 3498 rd.publicMethods = res; 3499 } 3500 return res; 3501 } 3502 3503 3504 // 3505 // Helpers for fetchers of one field, method, or constructor 3506 // 3507 3508 // This method does not copy the returned Field object! 3509 private static Field searchFields(Field[] fields, String name) { 3510 for (Field field : fields) { 3511 if (field.getName().equals(name)) { 3512 return field; 3513 } 3514 } 3515 return null; 3516 } 3517 3518 // Returns a "root" Field object. This Field object must NOT 3519 // be propagated to the outside world, but must instead be copied 3520 // via ReflectionFactory.copyField. 3521 private Field getField0(String name) { 3522 // Note: the intent is that the search algorithm this routine 3523 // uses be equivalent to the ordering imposed by 3524 // privateGetPublicFields(). It fetches only the declared 3525 // public fields for each class, however, to reduce the number 3526 // of Field objects which have to be created for the common 3527 // case where the field being requested is declared in the 3528 // class which is being queried. 3529 Field res; 3530 // Search declared public fields 3531 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) { 3532 return res; 3533 } 3534 // Direct superinterfaces, recursively 3535 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false); 3536 for (Class<?> c : interfaces) { 3537 if ((res = c.getField0(name)) != null) { 3538 return res; 3539 } 3540 } 3541 // Direct superclass, recursively 3542 if (!isInterface()) { 3543 Class<?> c = getSuperclass(); 3544 if (c != null) { 3545 if ((res = c.getField0(name)) != null) { 3546 return res; 3547 } 3548 } 3549 } 3550 return null; 3551 } 3552 3553 // This method does not copy the returned Method object! 3554 private static Method searchMethods(Method[] methods, 3555 String name, 3556 Class<?>[] parameterTypes) 3557 { 3558 ReflectionFactory fact = getReflectionFactory(); 3559 Method res = null; 3560 for (Method m : methods) { 3561 if (m.getName().equals(name) 3562 && arrayContentsEq(parameterTypes, 3563 fact.getExecutableSharedParameterTypes(m)) 3564 && (res == null 3565 || (res.getReturnType() != m.getReturnType() 3566 && res.getReturnType().isAssignableFrom(m.getReturnType())))) 3567 res = m; 3568 } 3569 return res; 3570 } 3571 3572 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0]; 3573 3574 // Returns a "root" Method object. This Method object must NOT 3575 // be propagated to the outside world, but must instead be copied 3576 // via ReflectionFactory.copyMethod. 3577 private Method getMethod0(String name, Class<?>[] parameterTypes) { 3578 PublicMethods.MethodList res = getMethodsRecursive( 3579 name, 3580 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes, 3581 /* includeStatic */ true); 3582 return res == null ? null : res.getMostSpecific(); 3583 } 3584 3585 // Returns a list of "root" Method objects. These Method objects must NOT 3586 // be propagated to the outside world, but must instead be copied 3587 // via ReflectionFactory.copyMethod. 3588 private PublicMethods.MethodList getMethodsRecursive(String name, 3589 Class<?>[] parameterTypes, 3590 boolean includeStatic) { 3591 // 1st check declared public methods 3592 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true); 3593 PublicMethods.MethodList res = PublicMethods.MethodList 3594 .filter(methods, name, parameterTypes, includeStatic); 3595 // if there is at least one match among declared methods, we need not 3596 // search any further as such match surely overrides matching methods 3597 // declared in superclass(es) or interface(s). 3598 if (res != null) { 3599 return res; 3600 } 3601 3602 // if there was no match among declared methods, 3603 // we must consult the superclass (if any) recursively... 3604 Class<?> sc = getSuperclass(); 3605 if (sc != null) { 3606 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic); 3607 } 3608 3609 // ...and coalesce the superclass methods with methods obtained 3610 // from directly implemented interfaces excluding static methods... 3611 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) { 3612 res = PublicMethods.MethodList.merge( 3613 res, intf.getMethodsRecursive(name, parameterTypes, 3614 /* includeStatic */ false)); 3615 } 3616 3617 return res; 3618 } 3619 3620 // Returns a "root" Constructor object. This Constructor object must NOT 3621 // be propagated to the outside world, but must instead be copied 3622 // via ReflectionFactory.copyConstructor. 3623 private Constructor<T> getConstructor0(Class<?>[] parameterTypes, 3624 int which) throws NoSuchMethodException 3625 { 3626 ReflectionFactory fact = getReflectionFactory(); 3627 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC)); 3628 for (Constructor<T> constructor : constructors) { 3629 if (arrayContentsEq(parameterTypes, 3630 fact.getExecutableSharedParameterTypes(constructor))) { 3631 return constructor; 3632 } 3633 } 3634 throw new NoSuchMethodException(methodToString("<init>", parameterTypes)); 3635 } 3636 3637 // 3638 // Other helpers and base implementation 3639 // 3640 3641 private static boolean arrayContentsEq(Object[] a1, Object[] a2) { 3642 if (a1 == null) { 3643 return a2 == null || a2.length == 0; 3644 } 3645 3646 if (a2 == null) { 3647 return a1.length == 0; 3648 } 3649 3650 if (a1.length != a2.length) { 3651 return false; 3652 } 3653 3654 for (int i = 0; i < a1.length; i++) { 3655 if (a1[i] != a2[i]) { 3656 return false; 3657 } 3658 } 3659 3660 return true; 3661 } 3662 3663 private static Field[] copyFields(Field[] arg) { 3664 Field[] out = new Field[arg.length]; 3665 ReflectionFactory fact = getReflectionFactory(); 3666 for (int i = 0; i < arg.length; i++) { 3667 out[i] = fact.copyField(arg[i]); 3668 } 3669 return out; 3670 } 3671 3672 private static Method[] copyMethods(Method[] arg) { 3673 Method[] out = new Method[arg.length]; 3674 ReflectionFactory fact = getReflectionFactory(); 3675 for (int i = 0; i < arg.length; i++) { 3676 out[i] = fact.copyMethod(arg[i]); 3677 } 3678 return out; 3679 } 3680 3681 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) { 3682 Constructor<U>[] out = arg.clone(); 3683 ReflectionFactory fact = getReflectionFactory(); 3684 for (int i = 0; i < out.length; i++) { 3685 out[i] = fact.copyConstructor(out[i]); 3686 } 3687 return out; 3688 } 3689 3690 private native Field[] getDeclaredFields0(boolean publicOnly); 3691 private native Method[] getDeclaredMethods0(boolean publicOnly); 3692 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly); 3693 private native Class<?>[] getDeclaredClasses0(); 3694 3695 /* 3696 * Returns an array containing the components of the Record attribute, 3697 * or null if the attribute is not present. 3698 * 3699 * Note that this method returns non-null array on a class with 3700 * the Record attribute even if this class is not a record. 3701 */ 3702 private native RecordComponent[] getRecordComponents0(); 3703 private native boolean isRecord0(); 3704 3705 /** 3706 * Helper method to get the method name from arguments. 3707 */ 3708 private String methodToString(String name, Class<?>[] argTypes) { 3709 return getName() + '.' + name + 3710 ((argTypes == null || argTypes.length == 0) ? 3711 "()" : 3712 Arrays.stream(argTypes) 3713 .map(c -> c == null ? "null" : c.getName()) 3714 .collect(Collectors.joining(",", "(", ")"))); 3715 } 3716 3717 /** use serialVersionUID from JDK 1.1 for interoperability */ 3718 @java.io.Serial 3719 private static final long serialVersionUID = 3206093459760846163L; 3720 3721 3722 /** 3723 * Class Class is special cased within the Serialization Stream Protocol. 3724 * 3725 * A Class instance is written initially into an ObjectOutputStream in the 3726 * following format: 3727 * <pre> 3728 * {@code TC_CLASS} ClassDescriptor 3729 * A ClassDescriptor is a special cased serialization of 3730 * a {@code java.io.ObjectStreamClass} instance. 3731 * </pre> 3732 * A new handle is generated for the initial time the class descriptor 3733 * is written into the stream. Future references to the class descriptor 3734 * are written as references to the initial class descriptor instance. 3735 * 3736 * @see java.io.ObjectStreamClass 3737 */ 3738 @java.io.Serial 3739 private static final ObjectStreamField[] serialPersistentFields = 3740 new ObjectStreamField[0]; 3741 3742 3743 /** 3744 * Returns the assertion status that would be assigned to this 3745 * class if it were to be initialized at the time this method is invoked. 3746 * If this class has had its assertion status set, the most recent 3747 * setting will be returned; otherwise, if any package default assertion 3748 * status pertains to this class, the most recent setting for the most 3749 * specific pertinent package default assertion status is returned; 3750 * otherwise, if this class is not a system class (i.e., it has a 3751 * class loader) its class loader's default assertion status is returned; 3752 * otherwise, the system class default assertion status is returned. 3753 * 3754 * @apiNote 3755 * Few programmers will have any need for this method; it is provided 3756 * for the benefit of the JDK itself. (It allows a class to determine at 3757 * the time that it is initialized whether assertions should be enabled.) 3758 * Note that this method is not guaranteed to return the actual 3759 * assertion status that was (or will be) associated with the specified 3760 * class when it was (or will be) initialized. 3761 * 3762 * @return the desired assertion status of the specified class. 3763 * @see java.lang.ClassLoader#setClassAssertionStatus 3764 * @see java.lang.ClassLoader#setPackageAssertionStatus 3765 * @see java.lang.ClassLoader#setDefaultAssertionStatus 3766 * @since 1.4 3767 */ 3768 public boolean desiredAssertionStatus() { 3769 ClassLoader loader = classLoader; 3770 // If the loader is null this is a system class, so ask the VM 3771 if (loader == null) 3772 return desiredAssertionStatus0(this); 3773 3774 // If the classloader has been initialized with the assertion 3775 // directives, ask it. Otherwise, ask the VM. 3776 synchronized(loader.assertionLock) { 3777 if (loader.classAssertionStatus != null) { 3778 return loader.desiredAssertionStatus(getName()); 3779 } 3780 } 3781 return desiredAssertionStatus0(this); 3782 } 3783 3784 // Retrieves the desired assertion status of this class from the VM 3785 private static native boolean desiredAssertionStatus0(Class<?> clazz); 3786 3787 /** 3788 * Returns true if and only if this class was declared as an enum in the 3789 * source code. 3790 * 3791 * Note that {@link java.lang.Enum} is not itself an enum class. 3792 * 3793 * Also note that if an enum constant is declared with a class body, 3794 * the class of that enum constant object is an anonymous class 3795 * and <em>not</em> the class of the declaring enum class. The 3796 * {@link Enum#getDeclaringClass} method of an enum constant can 3797 * be used to get the class of the enum class declaring the 3798 * constant. 3799 * 3800 * @return true if and only if this class was declared as an enum in the 3801 * source code 3802 * @since 1.5 3803 * @jls 8.9.1 Enum Constants 3804 */ 3805 public boolean isEnum() { 3806 // An enum must both directly extend java.lang.Enum and have 3807 // the ENUM bit set; classes for specialized enum constants 3808 // don't do the former. 3809 return (this.getModifiers() & ENUM) != 0 && 3810 this.getSuperclass() == java.lang.Enum.class; 3811 } 3812 3813 /** 3814 * Returns {@code true} if and only if this class is a record class. 3815 * 3816 * <p> The {@linkplain #getSuperclass() direct superclass} of a record 3817 * class is {@code java.lang.Record}. A record class is {@linkplain 3818 * Modifier#FINAL final}. A record class has (possibly zero) record 3819 * components; {@link #getRecordComponents()} returns a non-null but 3820 * possibly empty value for a record. 3821 * 3822 * <p> Note that class {@link Record} is not a record class and thus 3823 * invoking this method on class {@code Record} returns {@code false}. 3824 * 3825 * @return true if and only if this class is a record class, otherwise false 3826 * @jls 8.10 Record Classes 3827 * @since 16 3828 */ 3829 public boolean isRecord() { 3830 // this superclass and final modifier check is not strictly necessary 3831 // they are intrinsified and serve as a fast-path check 3832 return getSuperclass() == java.lang.Record.class && 3833 (this.getModifiers() & Modifier.FINAL) != 0 && 3834 isRecord0(); 3835 } 3836 3837 // Fetches the factory for reflective objects 3838 @SuppressWarnings("removal") 3839 private static ReflectionFactory getReflectionFactory() { 3840 var factory = reflectionFactory; 3841 if (factory != null) { 3842 return factory; 3843 } 3844 return reflectionFactory = 3845 java.security.AccessController.doPrivileged 3846 (new ReflectionFactory.GetReflectionFactoryAction()); 3847 } 3848 private static ReflectionFactory reflectionFactory; 3849 3850 /** 3851 * Returns the elements of this enum class or null if this 3852 * Class object does not represent an enum class. 3853 * 3854 * @return an array containing the values comprising the enum class 3855 * represented by this {@code Class} object in the order they're 3856 * declared, or null if this {@code Class} object does not 3857 * represent an enum class 3858 * @since 1.5 3859 * @jls 8.9.1 Enum Constants 3860 */ 3861 public T[] getEnumConstants() { 3862 T[] values = getEnumConstantsShared(); 3863 return (values != null) ? values.clone() : null; 3864 } 3865 3866 /** 3867 * Returns the elements of this enum class or null if this 3868 * Class object does not represent an enum class; 3869 * identical to getEnumConstants except that the result is 3870 * uncloned, cached, and shared by all callers. 3871 */ 3872 @SuppressWarnings("removal") 3873 T[] getEnumConstantsShared() { 3874 T[] constants = enumConstants; 3875 if (constants == null) { 3876 if (!isEnum()) return null; 3877 try { 3878 final Method values = getMethod("values"); 3879 java.security.AccessController.doPrivileged( 3880 new java.security.PrivilegedAction<>() { 3881 public Void run() { 3882 values.setAccessible(true); 3883 return null; 3884 } 3885 }); 3886 @SuppressWarnings("unchecked") 3887 T[] temporaryConstants = (T[])values.invoke(null); 3888 enumConstants = constants = temporaryConstants; 3889 } 3890 // These can happen when users concoct enum-like classes 3891 // that don't comply with the enum spec. 3892 catch (InvocationTargetException | NoSuchMethodException | 3893 IllegalAccessException ex) { return null; } 3894 } 3895 return constants; 3896 } 3897 private transient volatile T[] enumConstants; 3898 3899 /** 3900 * Returns a map from simple name to enum constant. This package-private 3901 * method is used internally by Enum to implement 3902 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)} 3903 * efficiently. Note that the map is returned by this method is 3904 * created lazily on first use. Typically it won't ever get created. 3905 */ 3906 Map<String, T> enumConstantDirectory() { 3907 Map<String, T> directory = enumConstantDirectory; 3908 if (directory == null) { 3909 T[] universe = getEnumConstantsShared(); 3910 if (universe == null) 3911 throw new IllegalArgumentException( 3912 getName() + " is not an enum class"); 3913 directory = new HashMap<>((int)(universe.length / 0.75f) + 1); 3914 for (T constant : universe) { 3915 directory.put(((Enum<?>)constant).name(), constant); 3916 } 3917 enumConstantDirectory = directory; 3918 } 3919 return directory; 3920 } 3921 private transient volatile Map<String, T> enumConstantDirectory; 3922 3923 /** 3924 * Casts an object to the class or interface represented 3925 * by this {@code Class} object. 3926 * 3927 * @param obj the object to be cast 3928 * @return the object after casting, or null if obj is null 3929 * 3930 * @throws ClassCastException if the object is not 3931 * null and is not assignable to the type T. 3932 * 3933 * @since 1.5 3934 */ 3935 @SuppressWarnings("unchecked") 3936 @IntrinsicCandidate 3937 public T cast(Object obj) { 3938 if (obj != null && !isInstance(obj)) 3939 throw new ClassCastException(cannotCastMsg(obj)); 3940 return (T) obj; 3941 } 3942 3943 private String cannotCastMsg(Object obj) { 3944 return "Cannot cast " + obj.getClass().getName() + " to " + getName(); 3945 } 3946 3947 /** 3948 * Casts this {@code Class} object to represent a subclass of the class 3949 * represented by the specified class object. Checks that the cast 3950 * is valid, and throws a {@code ClassCastException} if it is not. If 3951 * this method succeeds, it always returns a reference to this {@code Class} object. 3952 * 3953 * <p>This method is useful when a client needs to "narrow" the type of 3954 * a {@code Class} object to pass it to an API that restricts the 3955 * {@code Class} objects that it is willing to accept. A cast would 3956 * generate a compile-time warning, as the correctness of the cast 3957 * could not be checked at runtime (because generic types are implemented 3958 * by erasure). 3959 * 3960 * @param <U> the type to cast this {@code Class} object to 3961 * @param clazz the class of the type to cast this {@code Class} object to 3962 * @return this {@code Class} object, cast to represent a subclass of 3963 * the specified class object. 3964 * @throws ClassCastException if this {@code Class} object does not 3965 * represent a subclass of the specified class (here "subclass" includes 3966 * the class itself). 3967 * @since 1.5 3968 */ 3969 @SuppressWarnings("unchecked") 3970 public <U> Class<? extends U> asSubclass(Class<U> clazz) { 3971 if (clazz.isAssignableFrom(this)) 3972 return (Class<? extends U>) this; 3973 else 3974 throw new ClassCastException(this.toString()); 3975 } 3976 3977 /** 3978 * {@inheritDoc} 3979 * <p>Note that any annotation returned by this method is a 3980 * declaration annotation. 3981 * 3982 * @throws NullPointerException {@inheritDoc} 3983 * @since 1.5 3984 */ 3985 @Override 3986 @SuppressWarnings("unchecked") 3987 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) { 3988 Objects.requireNonNull(annotationClass); 3989 3990 return (A) annotationData().annotations.get(annotationClass); 3991 } 3992 3993 /** 3994 * {@inheritDoc} 3995 * @throws NullPointerException {@inheritDoc} 3996 * @since 1.5 3997 */ 3998 @Override 3999 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) { 4000 return GenericDeclaration.super.isAnnotationPresent(annotationClass); 4001 } 4002 4003 /** 4004 * {@inheritDoc} 4005 * <p>Note that any annotations returned by this method are 4006 * declaration annotations. 4007 * 4008 * @throws NullPointerException {@inheritDoc} 4009 * @since 1.8 4010 */ 4011 @Override 4012 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) { 4013 Objects.requireNonNull(annotationClass); 4014 4015 AnnotationData annotationData = annotationData(); 4016 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations, 4017 this, 4018 annotationClass); 4019 } 4020 4021 /** 4022 * {@inheritDoc} 4023 * <p>Note that any annotations returned by this method are 4024 * declaration annotations. 4025 * 4026 * @since 1.5 4027 */ 4028 @Override 4029 public Annotation[] getAnnotations() { 4030 return AnnotationParser.toArray(annotationData().annotations); 4031 } 4032 4033 /** 4034 * {@inheritDoc} 4035 * <p>Note that any annotation returned by this method is a 4036 * declaration annotation. 4037 * 4038 * @throws NullPointerException {@inheritDoc} 4039 * @since 1.8 4040 */ 4041 @Override 4042 @SuppressWarnings("unchecked") 4043 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) { 4044 Objects.requireNonNull(annotationClass); 4045 4046 return (A) annotationData().declaredAnnotations.get(annotationClass); 4047 } 4048 4049 /** 4050 * {@inheritDoc} 4051 * <p>Note that any annotations returned by this method are 4052 * declaration annotations. 4053 * 4054 * @throws NullPointerException {@inheritDoc} 4055 * @since 1.8 4056 */ 4057 @Override 4058 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) { 4059 Objects.requireNonNull(annotationClass); 4060 4061 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations, 4062 annotationClass); 4063 } 4064 4065 /** 4066 * {@inheritDoc} 4067 * <p>Note that any annotations returned by this method are 4068 * declaration annotations. 4069 * 4070 * @since 1.5 4071 */ 4072 @Override 4073 public Annotation[] getDeclaredAnnotations() { 4074 return AnnotationParser.toArray(annotationData().declaredAnnotations); 4075 } 4076 4077 // annotation data that might get invalidated when JVM TI RedefineClasses() is called 4078 private static class AnnotationData { 4079 final Map<Class<? extends Annotation>, Annotation> annotations; 4080 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations; 4081 4082 // Value of classRedefinedCount when we created this AnnotationData instance 4083 final int redefinedCount; 4084 4085 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations, 4086 Map<Class<? extends Annotation>, Annotation> declaredAnnotations, 4087 int redefinedCount) { 4088 this.annotations = annotations; 4089 this.declaredAnnotations = declaredAnnotations; 4090 this.redefinedCount = redefinedCount; 4091 } 4092 } 4093 4094 // Annotations cache 4095 @SuppressWarnings("UnusedDeclaration") 4096 private transient volatile AnnotationData annotationData; 4097 4098 private AnnotationData annotationData() { 4099 while (true) { // retry loop 4100 AnnotationData annotationData = this.annotationData; 4101 int classRedefinedCount = this.classRedefinedCount; 4102 if (annotationData != null && 4103 annotationData.redefinedCount == classRedefinedCount) { 4104 return annotationData; 4105 } 4106 // null or stale annotationData -> optimistically create new instance 4107 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount); 4108 // try to install it 4109 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) { 4110 // successfully installed new AnnotationData 4111 return newAnnotationData; 4112 } 4113 } 4114 } 4115 4116 private AnnotationData createAnnotationData(int classRedefinedCount) { 4117 Map<Class<? extends Annotation>, Annotation> declaredAnnotations = 4118 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this); 4119 Class<?> superClass = getSuperclass(); 4120 Map<Class<? extends Annotation>, Annotation> annotations = null; 4121 if (superClass != null) { 4122 Map<Class<? extends Annotation>, Annotation> superAnnotations = 4123 superClass.annotationData().annotations; 4124 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) { 4125 Class<? extends Annotation> annotationClass = e.getKey(); 4126 if (AnnotationType.getInstance(annotationClass).isInherited()) { 4127 if (annotations == null) { // lazy construction 4128 annotations = new LinkedHashMap<>((Math.max( 4129 declaredAnnotations.size(), 4130 Math.min(12, declaredAnnotations.size() + superAnnotations.size()) 4131 ) * 4 + 2) / 3 4132 ); 4133 } 4134 annotations.put(annotationClass, e.getValue()); 4135 } 4136 } 4137 } 4138 if (annotations == null) { 4139 // no inherited annotations -> share the Map with declaredAnnotations 4140 annotations = declaredAnnotations; 4141 } else { 4142 // at least one inherited annotation -> declared may override inherited 4143 annotations.putAll(declaredAnnotations); 4144 } 4145 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount); 4146 } 4147 4148 // Annotation interfaces cache their internal (AnnotationType) form 4149 4150 @SuppressWarnings("UnusedDeclaration") 4151 private transient volatile AnnotationType annotationType; 4152 4153 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) { 4154 return Atomic.casAnnotationType(this, oldType, newType); 4155 } 4156 4157 AnnotationType getAnnotationType() { 4158 return annotationType; 4159 } 4160 4161 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() { 4162 return annotationData().declaredAnnotations; 4163 } 4164 4165 /* Backing store of user-defined values pertaining to this class. 4166 * Maintained by the ClassValue class. 4167 */ 4168 transient ClassValue.ClassValueMap classValueMap; 4169 4170 /** 4171 * Returns an {@code AnnotatedType} object that represents the use of a 4172 * type to specify the superclass of the entity represented by this {@code 4173 * Class} object. (The <em>use</em> of type Foo to specify the superclass 4174 * in '... extends Foo' is distinct from the <em>declaration</em> of class 4175 * Foo.) 4176 * 4177 * <p> If this {@code Class} object represents a class whose declaration 4178 * does not explicitly indicate an annotated superclass, then the return 4179 * value is an {@code AnnotatedType} object representing an element with no 4180 * annotations. 4181 * 4182 * <p> If this {@code Class} represents either the {@code Object} class, an 4183 * interface type, an array type, a primitive type, or void, the return 4184 * value is {@code null}. 4185 * 4186 * @return an object representing the superclass 4187 * @since 1.8 4188 */ 4189 public AnnotatedType getAnnotatedSuperclass() { 4190 if (this == Object.class || 4191 isInterface() || 4192 isArray() || 4193 isPrimitive() || 4194 this == Void.TYPE) { 4195 return null; 4196 } 4197 4198 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this); 4199 } 4200 4201 /** 4202 * Returns an array of {@code AnnotatedType} objects that represent the use 4203 * of types to specify superinterfaces of the entity represented by this 4204 * {@code Class} object. (The <em>use</em> of type Foo to specify a 4205 * superinterface in '... implements Foo' is distinct from the 4206 * <em>declaration</em> of interface Foo.) 4207 * 4208 * <p> If this {@code Class} object represents a class, the return value is 4209 * an array containing objects representing the uses of interface types to 4210 * specify interfaces implemented by the class. The order of the objects in 4211 * the array corresponds to the order of the interface types used in the 4212 * 'implements' clause of the declaration of this {@code Class} object. 4213 * 4214 * <p> If this {@code Class} object represents an interface, the return 4215 * value is an array containing objects representing the uses of interface 4216 * types to specify interfaces directly extended by the interface. The 4217 * order of the objects in the array corresponds to the order of the 4218 * interface types used in the 'extends' clause of the declaration of this 4219 * {@code Class} object. 4220 * 4221 * <p> If this {@code Class} object represents a class or interface whose 4222 * declaration does not explicitly indicate any annotated superinterfaces, 4223 * the return value is an array of length 0. 4224 * 4225 * <p> If this {@code Class} object represents either the {@code Object} 4226 * class, an array type, a primitive type, or void, the return value is an 4227 * array of length 0. 4228 * 4229 * @return an array representing the superinterfaces 4230 * @since 1.8 4231 */ 4232 public AnnotatedType[] getAnnotatedInterfaces() { 4233 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this); 4234 } 4235 4236 private native Class<?> getNestHost0(); 4237 4238 /** 4239 * Returns the nest host of the <a href=#nest>nest</a> to which the class 4240 * or interface represented by this {@code Class} object belongs. 4241 * Every class and interface belongs to exactly one nest. 4242 * 4243 * If the nest host of this class or interface has previously 4244 * been determined, then this method returns the nest host. 4245 * If the nest host of this class or interface has 4246 * not previously been determined, then this method determines the nest 4247 * host using the algorithm of JVMS 5.4.4, and returns it. 4248 * 4249 * Often, a class or interface belongs to a nest consisting only of itself, 4250 * in which case this method returns {@code this} to indicate that the class 4251 * or interface is the nest host. 4252 * 4253 * <p>If this {@code Class} object represents a primitive type, an array type, 4254 * or {@code void}, then this method returns {@code this}, 4255 * indicating that the represented entity belongs to the nest consisting only of 4256 * itself, and is the nest host. 4257 * 4258 * @return the nest host of this class or interface 4259 * 4260 * @throws SecurityException 4261 * If the returned class is not the current class, and 4262 * if a security manager, <i>s</i>, is present and the caller's 4263 * class loader is not the same as or an ancestor of the class 4264 * loader for the returned class and invocation of {@link 4265 * SecurityManager#checkPackageAccess s.checkPackageAccess()} 4266 * denies access to the package of the returned class 4267 * @since 11 4268 * @jvms 4.7.28 The {@code NestHost} Attribute 4269 * @jvms 4.7.29 The {@code NestMembers} Attribute 4270 * @jvms 5.4.4 Access Control 4271 */ 4272 @CallerSensitive 4273 public Class<?> getNestHost() { 4274 if (isPrimitive() || isArray()) { 4275 return this; 4276 } 4277 4278 Class<?> host = getNestHost0(); 4279 if (host == this) { 4280 return this; 4281 } 4282 // returning a different class requires a security check 4283 @SuppressWarnings("removal") 4284 SecurityManager sm = System.getSecurityManager(); 4285 if (sm != null) { 4286 checkPackageAccess(sm, 4287 ClassLoader.getClassLoader(Reflection.getCallerClass()), true); 4288 } 4289 return host; 4290 } 4291 4292 /** 4293 * Determines if the given {@code Class} is a nestmate of the 4294 * class or interface represented by this {@code Class} object. 4295 * Two classes or interfaces are nestmates 4296 * if they have the same {@linkplain #getNestHost() nest host}. 4297 * 4298 * @param c the class to check 4299 * @return {@code true} if this class and {@code c} are members of 4300 * the same nest; and {@code false} otherwise. 4301 * 4302 * @since 11 4303 */ 4304 public boolean isNestmateOf(Class<?> c) { 4305 if (this == c) { 4306 return true; 4307 } 4308 if (isPrimitive() || isArray() || 4309 c.isPrimitive() || c.isArray()) { 4310 return false; 4311 } 4312 4313 return getNestHost() == c.getNestHost(); 4314 } 4315 4316 private native Class<?>[] getNestMembers0(); 4317 4318 /** 4319 * Returns an array containing {@code Class} objects representing all the 4320 * classes and interfaces that are members of the nest to which the class 4321 * or interface represented by this {@code Class} object belongs. 4322 * 4323 * First, this method obtains the {@linkplain #getNestHost() nest host}, 4324 * {@code H}, of the nest to which the class or interface represented by 4325 * this {@code Class} object belongs. The zeroth element of the returned 4326 * array is {@code H}. 4327 * 4328 * Then, for each class or interface {@code C} which is recorded by {@code H} 4329 * as being a member of its nest, this method attempts to obtain the {@code Class} 4330 * object for {@code C} (using {@linkplain #getClassLoader() the defining class 4331 * loader} of the current {@code Class} object), and then obtains the 4332 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs. 4333 * The classes and interfaces which are recorded by {@code H} as being members 4334 * of its nest, and for which {@code H} can be determined as their nest host, 4335 * are indicated by subsequent elements of the returned array. The order of 4336 * such elements is unspecified. Duplicates are permitted. 4337 * 4338 * <p>If this {@code Class} object represents a primitive type, an array type, 4339 * or {@code void}, then this method returns a single-element array containing 4340 * {@code this}. 4341 * 4342 * @apiNote 4343 * The returned array includes only the nest members recorded in the {@code NestMembers} 4344 * attribute, and not any hidden classes that were added to the nest via 4345 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 4346 * Lookup::defineHiddenClass}. 4347 * 4348 * @return an array of all classes and interfaces in the same nest as 4349 * this class or interface 4350 * 4351 * @throws SecurityException 4352 * If any returned class is not the current class, and 4353 * if a security manager, <i>s</i>, is present and the caller's 4354 * class loader is not the same as or an ancestor of the class 4355 * loader for that returned class and invocation of {@link 4356 * SecurityManager#checkPackageAccess s.checkPackageAccess()} 4357 * denies access to the package of that returned class 4358 * 4359 * @since 11 4360 * @see #getNestHost() 4361 * @jvms 4.7.28 The {@code NestHost} Attribute 4362 * @jvms 4.7.29 The {@code NestMembers} Attribute 4363 */ 4364 @CallerSensitive 4365 public Class<?>[] getNestMembers() { 4366 if (isPrimitive() || isArray()) { 4367 return new Class<?>[] { this }; 4368 } 4369 Class<?>[] members = getNestMembers0(); 4370 // Can't actually enable this due to bootstrapping issues 4371 // assert(members.length != 1 || members[0] == this); // expected invariant from VM 4372 4373 if (members.length > 1) { 4374 // If we return anything other than the current class we need 4375 // a security check 4376 @SuppressWarnings("removal") 4377 SecurityManager sm = System.getSecurityManager(); 4378 if (sm != null) { 4379 checkPackageAccess(sm, 4380 ClassLoader.getClassLoader(Reflection.getCallerClass()), true); 4381 } 4382 } 4383 return members; 4384 } 4385 4386 /** 4387 * Returns the descriptor string of the entity (class, interface, array class, 4388 * primitive type, or {@code void}) represented by this {@code Class} object. 4389 * 4390 * <p> If this {@code Class} object represents a class or interface, 4391 * not an array class, then: 4392 * <ul> 4393 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden}, 4394 * then the result is a field descriptor (JVMS {@jvms 4.3.2}) 4395 * for the class or interface. Calling 4396 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor} 4397 * with the result descriptor string produces a {@link ClassDesc ClassDesc} 4398 * describing this class or interface. 4399 * <li> If the class or interface is {@linkplain Class#isHidden() hidden}, 4400 * then the result is a string of the form: 4401 * <blockquote> 4402 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"} 4403 * </blockquote> 4404 * where <em>N</em> is the <a href="ClassLoader.html#binary-name">binary name</a> 4405 * encoded in internal form indicated by the {@code class} file passed to 4406 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 4407 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name. 4408 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}. 4409 * The result string is not a type descriptor. 4410 * </ul> 4411 * 4412 * <p> If this {@code Class} object represents an array class, then 4413 * the result is a string consisting of one or more '{@code [}' characters 4414 * representing the depth of the array nesting, followed by the 4415 * descriptor string of the element type. 4416 * <ul> 4417 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class 4418 * or interface, then this array class can be described nominally. 4419 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor} 4420 * with the result descriptor string produces a {@link ClassDesc ClassDesc} 4421 * describing this array class. 4422 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or 4423 * interface, then this array class cannot be described nominally. 4424 * The result string is not a type descriptor. 4425 * </ul> 4426 * 4427 * <p> If this {@code Class} object represents a primitive type or 4428 * {@code void}, then the result is a field descriptor string which 4429 * is a one-letter code corresponding to a primitive type or {@code void} 4430 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}). 4431 * 4432 * @apiNote 4433 * This is not a strict inverse of {@link #forName}; 4434 * distinct classes which share a common name but have different class loaders 4435 * will have identical descriptor strings. 4436 * 4437 * @return the descriptor string for this {@code Class} object 4438 * @jvms 4.3.2 Field Descriptors 4439 * @since 12 4440 */ 4441 @Override 4442 public String descriptorString() { 4443 if (isPrimitive()) 4444 return Wrapper.forPrimitiveType(this).basicTypeString(); 4445 4446 if (isArray()) { 4447 return "[" + componentType.descriptorString(); 4448 } else if (isHidden()) { 4449 String name = getName(); 4450 int index = name.indexOf('/'); 4451 return new StringBuilder(name.length() + 2) 4452 .append('L') 4453 .append(name.substring(0, index).replace('.', '/')) 4454 .append('.') 4455 .append(name, index + 1, name.length()) 4456 .append(';') 4457 .toString(); 4458 } else { 4459 String name = getName().replace('.', '/'); 4460 return new StringBuilder(name.length() + 2) 4461 .append('L') 4462 .append(name) 4463 .append(';') 4464 .toString(); 4465 } 4466 } 4467 4468 /** 4469 * Returns the component type of this {@code Class}, if it describes 4470 * an array type, or {@code null} otherwise. 4471 * 4472 * @implSpec 4473 * Equivalent to {@link Class#getComponentType()}. 4474 * 4475 * @return a {@code Class} describing the component type, or {@code null} 4476 * if this {@code Class} does not describe an array type 4477 * @since 12 4478 */ 4479 @Override 4480 public Class<?> componentType() { 4481 return isArray() ? componentType : null; 4482 } 4483 4484 /** 4485 * Returns a {@code Class} for an array type whose component type 4486 * is described by this {@linkplain Class}. 4487 * 4488 * @throws UnsupportedOperationException if this component type is {@linkplain 4489 * Void#TYPE void} or if the number of dimensions of the resulting array 4490 * type would exceed 255. 4491 * @return a {@code Class} describing the array type 4492 * @jvms 4.3.2 Field Descriptors 4493 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure 4494 * @since 12 4495 */ 4496 @Override 4497 public Class<?> arrayType() { 4498 try { 4499 return Array.newInstance(this, 0).getClass(); 4500 } catch (IllegalArgumentException iae) { 4501 throw new UnsupportedOperationException(iae); 4502 } 4503 } 4504 4505 /** 4506 * Returns a nominal descriptor for this instance, if one can be 4507 * constructed, or an empty {@link Optional} if one cannot be. 4508 * 4509 * @return An {@link Optional} containing the resulting nominal descriptor, 4510 * or an empty {@link Optional} if one cannot be constructed. 4511 * @since 12 4512 */ 4513 @Override 4514 public Optional<ClassDesc> describeConstable() { 4515 Class<?> c = isArray() ? elementType() : this; 4516 return c.isHidden() ? Optional.empty() 4517 : Optional.of(ClassDesc.ofDescriptor(descriptorString())); 4518 } 4519 4520 /** 4521 * Returns {@code true} if and only if the underlying class is a hidden class. 4522 * 4523 * @return {@code true} if and only if this class is a hidden class. 4524 * 4525 * @since 15 4526 * @see MethodHandles.Lookup#defineHiddenClass 4527 */ 4528 @IntrinsicCandidate 4529 public native boolean isHidden(); 4530 4531 /** 4532 * Returns an array containing {@code Class} objects representing the 4533 * direct subinterfaces or subclasses permitted to extend or 4534 * implement this class or interface if it is sealed. The order of such elements 4535 * is unspecified. The array is empty if this sealed class or interface has no 4536 * permitted subclass. If this {@code Class} object represents a primitive type, 4537 * {@code void}, an array type, or a class or interface that is not sealed, 4538 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}. 4539 * Conversely, if {@link #isSealed()} returns {@code true}, then this method 4540 * returns a non-null value. 4541 * 4542 * For each class or interface {@code C} which is recorded as a permitted 4543 * direct subinterface or subclass of this class or interface, 4544 * this method attempts to obtain the {@code Class} 4545 * object for {@code C} (using {@linkplain #getClassLoader() the defining class 4546 * loader} of the current {@code Class} object). 4547 * The {@code Class} objects which can be obtained and which are direct 4548 * subinterfaces or subclasses of this class or interface, 4549 * are indicated by elements of the returned array. If a {@code Class} object 4550 * cannot be obtained, it is silently ignored, and not included in the result 4551 * array. 4552 * 4553 * @return an array of {@code Class} objects of the permitted subclasses of this class or interface, 4554 * or {@code null} if this class or interface is not sealed. 4555 * 4556 * @throws SecurityException 4557 * If a security manager, <i>s</i>, is present and the caller's 4558 * class loader is not the same as or an ancestor of the class 4559 * loader for that returned class and invocation of {@link 4560 * SecurityManager#checkPackageAccess s.checkPackageAccess()} 4561 * denies access to the package of any class in the returned array. 4562 * 4563 * @jls 8.1 Class Declarations 4564 * @jls 9.1 Interface Declarations 4565 * @since 17 4566 */ 4567 @CallerSensitive 4568 public Class<?>[] getPermittedSubclasses() { 4569 Class<?>[] subClasses; 4570 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) { 4571 return null; 4572 } 4573 if (subClasses.length > 0) { 4574 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) { 4575 subClasses = Arrays.stream(subClasses) 4576 .filter(this::isDirectSubType) 4577 .toArray(s -> new Class<?>[s]); 4578 } 4579 } 4580 if (subClasses.length > 0) { 4581 // If we return some classes we need a security check: 4582 @SuppressWarnings("removal") 4583 SecurityManager sm = System.getSecurityManager(); 4584 if (sm != null) { 4585 checkPackageAccessForPermittedSubclasses(sm, 4586 ClassLoader.getClassLoader(Reflection.getCallerClass()), 4587 subClasses); 4588 } 4589 } 4590 return subClasses; 4591 } 4592 4593 private boolean isDirectSubType(Class<?> c) { 4594 if (isInterface()) { 4595 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) { 4596 if (i == this) { 4597 return true; 4598 } 4599 } 4600 } else { 4601 return c.getSuperclass() == this; 4602 } 4603 return false; 4604 } 4605 4606 /** 4607 * Returns {@code true} if and only if this {@code Class} object represents 4608 * a sealed class or interface. If this {@code Class} object represents a 4609 * primitive type, {@code void}, or an array type, this method returns 4610 * {@code false}. A sealed class or interface has (possibly zero) permitted 4611 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but 4612 * possibly empty value for a sealed class or interface. 4613 * 4614 * @return {@code true} if and only if this {@code Class} object represents 4615 * a sealed class or interface. 4616 * 4617 * @jls 8.1 Class Declarations 4618 * @jls 9.1 Interface Declarations 4619 * @since 17 4620 */ 4621 public boolean isSealed() { 4622 if (isArray() || isPrimitive()) { 4623 return false; 4624 } 4625 return getPermittedSubclasses() != null; 4626 } 4627 4628 private native Class<?>[] getPermittedSubclasses0(); 4629 }