1 /* 2 * Copyright (c) 1994, 2025, 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.constant.ConstantDescs; 31 import java.lang.invoke.TypeDescriptor; 32 import java.lang.invoke.MethodHandles; 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.AccessFlag; 40 import java.lang.reflect.Array; 41 import java.lang.reflect.ClassFileFormatVersion; 42 import java.lang.reflect.Constructor; 43 import java.lang.reflect.Executable; 44 import java.lang.reflect.Field; 45 import java.lang.reflect.GenericArrayType; 46 import java.lang.reflect.GenericDeclaration; 47 import java.lang.reflect.InvocationTargetException; 48 import java.lang.reflect.Member; 49 import java.lang.reflect.Method; 50 import java.lang.reflect.Modifier; 51 import java.lang.reflect.RecordComponent; 52 import java.lang.reflect.Type; 53 import java.lang.reflect.TypeVariable; 54 import java.lang.constant.Constable; 55 import java.net.URL; 56 import java.security.AllPermission; 57 import java.security.Permissions; 58 import java.security.ProtectionDomain; 59 import java.util.ArrayList; 60 import java.util.Arrays; 61 import java.util.Collection; 62 import java.util.HashMap; 63 import java.util.HashSet; 64 import java.util.LinkedHashMap; 65 import java.util.LinkedHashSet; 66 import java.util.List; 67 import java.util.Map; 68 import java.util.Objects; 69 import java.util.Optional; 70 import java.util.Set; 71 import java.util.stream.Collectors; 72 73 import jdk.internal.constant.ConstantUtils; 74 import jdk.internal.javac.PreviewFeature; 75 import jdk.internal.loader.BootLoader; 76 import jdk.internal.loader.BuiltinClassLoader; 77 import jdk.internal.misc.PreviewFeatures; 78 import jdk.internal.misc.Unsafe; 79 import jdk.internal.module.Resources; 80 import jdk.internal.reflect.CallerSensitive; 81 import jdk.internal.reflect.CallerSensitiveAdapter; 82 import jdk.internal.reflect.ConstantPool; 83 import jdk.internal.reflect.Reflection; 84 import jdk.internal.reflect.ReflectionFactory; 85 import jdk.internal.util.ModifiedUtf; 86 import jdk.internal.vm.annotation.AOTRuntimeSetup; 87 import jdk.internal.vm.annotation.AOTSafeClassInitializer; 88 import jdk.internal.vm.annotation.IntrinsicCandidate; 89 import jdk.internal.vm.annotation.Stable; 90 91 import sun.invoke.util.Wrapper; 92 import sun.reflect.generics.factory.CoreReflectionFactory; 93 import sun.reflect.generics.factory.GenericsFactory; 94 import sun.reflect.generics.repository.ClassRepository; 95 import sun.reflect.generics.repository.MethodRepository; 96 import sun.reflect.generics.repository.ConstructorRepository; 97 import sun.reflect.generics.scope.ClassScope; 98 import sun.reflect.annotation.*; 99 100 /** 101 * Instances of the class {@code Class} represent classes and 102 * interfaces in a running Java application. An enum class and a record 103 * class are kinds of class; an annotation interface is a kind of 104 * interface. Every array also belongs to a class that is reflected as 105 * a {@code Class} object that is shared by all arrays with the same 106 * element type and number of dimensions. The primitive Java types 107 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code 108 * int}, {@code long}, {@code float}, and {@code double}), and the 109 * keyword {@code void} are also represented as {@code Class} objects. 110 * 111 * <p> {@code Class} has no public constructor. Instead a {@code Class} 112 * object is constructed automatically by the Java Virtual Machine when 113 * a class is derived from the bytes of a {@code class} file through 114 * the invocation of one of the following methods: 115 * <ul> 116 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass} 117 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[]) 118 * java.lang.invoke.MethodHandles.Lookup::defineClass} 119 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 120 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass} 121 * </ul> 122 * 123 * <p> The methods of class {@code Class} expose many characteristics of a 124 * class or interface. Most characteristics are derived from the {@code class} 125 * file that the class loader passed to the Java Virtual Machine or 126 * from the {@code class} file passed to {@code Lookup::defineClass} 127 * or {@code Lookup::defineHiddenClass}. 128 * A few characteristics are determined by the class loading environment 129 * at run time, such as the module returned by {@link #getModule() getModule()}. 130 * 131 * <p> The following example uses a {@code Class} object to print the 132 * class name of an object: 133 * 134 * {@snippet lang="java" : 135 * void printClassName(Object obj) { 136 * System.out.println("The class of " + obj + 137 * " is " + obj.getClass().getName()); 138 * }} 139 * 140 * It is also possible to get the {@code Class} object for a named 141 * class or interface (or for {@code void}) using a <dfn>class literal</dfn> 142 * (JLS {@jls 15.8.2}). 143 * For example: 144 * 145 * {@snippet lang="java" : 146 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class" 147 * } 148 * 149 * <p> Some methods of class {@code Class} expose whether the declaration of 150 * a class or interface in Java source code was <em>enclosed</em> within 151 * another declaration. Other methods describe how a class or interface 152 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of 153 * classes and interfaces, in the same run-time package, that 154 * allow mutual access to their {@code private} members. 155 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn> 156 * (JVMS {@jvms 4.7.29}). 157 * One nestmate acts as the 158 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which 159 * belong to the nest; each of them in turn records it as the nest host. 160 * The classes and interfaces which belong to a nest, including its host, are 161 * determined when 162 * {@code class} files are generated, for example, a Java compiler 163 * will typically record a top-level class as the host of a nest where the 164 * other members are the classes and interfaces whose declarations are 165 * enclosed within the top-level class declaration. 166 * 167 * <h2><a id=hiddenClasses>Hidden Classes</a></h2> 168 * A class or interface created by the invocation of 169 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 170 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>} 171 * class or interface. 172 * All kinds of class, including enum classes and record classes, may be 173 * hidden classes; all kinds of interface, including annotation interfaces, 174 * may be hidden interfaces. 175 * 176 * The {@linkplain #getName() name of a hidden class or interface} is 177 * not a {@linkplain ClassLoader##binary-name binary name}, 178 * which means the following: 179 * <ul> 180 * <li>A hidden class or interface cannot be referenced by the constant pools 181 * of other classes and interfaces. 182 * <li>A hidden class or interface cannot be described in 183 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by 184 * {@link #describeConstable() Class::describeConstable}, 185 * {@link ClassDesc#of(String) ClassDesc::of}, or 186 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}. 187 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName} 188 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}. 189 * </ul> 190 * 191 * A hidden class or interface is never an array class, but may be 192 * the element type of an array. In all other respects, the fact that 193 * a class or interface is hidden has no bearing on the characteristics 194 * exposed by the methods of class {@code Class}. 195 * 196 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2> 197 * 198 * Conventionally, a Java compiler, starting from a source file for an 199 * implicitly declared class, say {@code HelloWorld.java}, creates a 200 * similarly-named {@code class} file, {@code HelloWorld.class}, where 201 * the class stored in that {@code class} file is named {@code 202 * "HelloWorld"}, matching the base names of the source and {@code 203 * class} files. 204 * 205 * For the {@code Class} object of an implicitly declared class {@code 206 * HelloWorld}, the methods to get the {@linkplain #getName name} and 207 * {@linkplain #getTypeName type name} return results 208 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName 209 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and 210 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}. 211 * 212 * @param <T> the type of the class modeled by this {@code Class} 213 * object. For example, the type of {@code String.class} is {@code 214 * Class<String>}. Use {@code Class<?>} if the class being modeled is 215 * unknown. 216 * 217 * @see java.lang.ClassLoader#defineClass(byte[], int, int) 218 * @since 1.0 219 */ 220 @AOTSafeClassInitializer 221 public final class Class<T> implements java.io.Serializable, 222 GenericDeclaration, 223 Type, 224 AnnotatedElement, 225 TypeDescriptor.OfField<Class<?>>, 226 Constable { 227 private static final int ANNOTATION = 0x00002000; 228 private static final int ENUM = 0x00004000; 229 private static final int SYNTHETIC = 0x00001000; 230 231 private static native void registerNatives(); 232 static { 233 runtimeSetup(); 234 } 235 236 /// No significant static final fields; [#resetArchivedStates()] handles 237 /// prevents storing [#reflectionFactory] into AOT image. 238 @AOTRuntimeSetup 239 private static void runtimeSetup() { 240 registerNatives(); 241 } 242 243 /* 244 * Private constructor. Only the Java Virtual Machine creates Class objects. 245 * This constructor is not used and prevents the default constructor being 246 * generated. 247 */ 248 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, char flags) { 249 // Initialize final field for classLoader. The initialization value of non-null 250 // prevents future JIT optimizations from assuming this final field is null. 251 // The following assignments are done directly by the VM without calling this constructor. 252 classLoader = loader; 253 componentType = arrayComponentType; 254 modifiers = mods; 255 protectionDomain = pd; 256 primitive = isPrim; 257 classFileAccessFlags = flags; 258 } 259 260 /** 261 * Converts the object to a string. The string representation is the 262 * string "class" or "interface", followed by a space, and then by the 263 * name of the class in the format returned by {@code getName}. 264 * If this {@code Class} object represents a primitive type, 265 * this method returns the name of the primitive type. If 266 * this {@code Class} object represents void this method returns 267 * "void". If this {@code Class} object represents an array type, 268 * this method returns "class " followed by {@code getName}. 269 * 270 * @return a string representation of this {@code Class} object. 271 */ 272 public String toString() { 273 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class "; 274 return kind.concat(getName()); 275 } 276 277 /** 278 * Returns a string describing this {@code Class}, including 279 * information about modifiers, {@link #isSealed() sealed}/{@code 280 * non-sealed} status, and type parameters. 281 * 282 * The string is formatted as a list of type modifiers, if any, 283 * followed by the kind of type (empty string for primitive types 284 * and {@code class}, {@code enum}, {@code interface}, 285 * {@code @interface}, or {@code record} as appropriate), followed 286 * by the type's name, followed by an angle-bracketed 287 * comma-separated list of the type's type parameters, if any, 288 * including informative bounds on the type parameters, if any. 289 * 290 * A space is used to separate modifiers from one another and to 291 * separate any modifiers from the kind of type. The modifiers 292 * occur in canonical order. If there are no type parameters, the 293 * type parameter list is elided. 294 * 295 * For an array type, the string starts with the type name, 296 * followed by an angle-bracketed comma-separated list of the 297 * type's type parameters, if any, followed by a sequence of 298 * {@code []} characters, one set of brackets per dimension of 299 * the array. 300 * 301 * <p>Note that since information about the runtime representation 302 * of a type is being generated, modifiers not present on the 303 * originating source code or illegal on the originating source 304 * code may be present. 305 * 306 * @return a string describing this {@code Class}, including 307 * information about modifiers and type parameters 308 * 309 * @since 1.8 310 */ 311 public String toGenericString() { 312 if (isPrimitive()) { 313 return toString(); 314 } else { 315 StringBuilder sb = new StringBuilder(); 316 Class<?> component = this; 317 int arrayDepth = 0; 318 319 if (isArray()) { 320 do { 321 arrayDepth++; 322 component = component.getComponentType(); 323 } while (component.isArray()); 324 sb.append(component.getName()); 325 } else { 326 // Class modifiers are a superset of interface modifiers 327 int modifiers = getModifiers() & Modifier.classModifiers(); 328 // Modifier.toString() below mis-interprets SYNCHRONIZED, STRICT, and VOLATILE bits 329 modifiers &= ~(Modifier.SYNCHRONIZED | Modifier.STRICT | Modifier.VOLATILE); 330 if (modifiers != 0) { 331 sb.append(Modifier.toString(modifiers)); 332 sb.append(' '); 333 } 334 335 // A class cannot be strictfp and sealed/non-sealed so 336 // it is sufficient to check for sealed-ness after all 337 // modifiers are printed. 338 addSealingInfo(modifiers, sb); 339 340 if (isAnnotation()) { 341 sb.append('@'); 342 } 343 if (isInterface()) { // Note: all annotation interfaces are interfaces 344 sb.append("interface"); 345 } else { 346 if (isEnum()) 347 sb.append("enum"); 348 else { 349 if (isValue()) { 350 sb.append("value "); 351 } 352 if (isRecord()) 353 sb.append("record"); 354 else 355 sb.append("class"); 356 } 357 } 358 sb.append(' '); 359 sb.append(getName()); 360 } 361 362 TypeVariable<?>[] typeparms = component.getTypeParameters(); 363 if (typeparms.length > 0) { 364 sb.append(Arrays.stream(typeparms) 365 .map(Class::typeVarBounds) 366 .collect(Collectors.joining(",", "<", ">"))); 367 } 368 369 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth)); 370 371 return sb.toString(); 372 } 373 } 374 375 private void addSealingInfo(int modifiers, StringBuilder sb) { 376 // A class can be final XOR sealed XOR non-sealed. 377 if (Modifier.isFinal(modifiers)) { 378 return; // no-op 379 } else { 380 if (isSealed()) { 381 sb.append("sealed "); 382 return; 383 } else { 384 // Check for sealed ancestor, which implies this class 385 // is non-sealed. 386 if (hasSealedAncestor(this)) { 387 sb.append("non-sealed "); 388 } 389 } 390 } 391 } 392 393 private boolean hasSealedAncestor(Class<?> clazz) { 394 // From JLS 8.1.1.2: 395 // "It is a compile-time error if a class has a sealed direct 396 // superclass or a sealed direct superinterface, and is not 397 // declared final, sealed, or non-sealed either explicitly or 398 // implicitly. 399 // Thus, an effect of the sealed keyword is to force all 400 // direct subclasses to explicitly declare whether they are 401 // final, sealed, or non-sealed. This avoids accidentally 402 // exposing a sealed class hierarchy to unwanted subclassing." 403 404 // Therefore, will just check direct superclass and 405 // superinterfaces. 406 var superclass = clazz.getSuperclass(); 407 if (superclass != null && superclass.isSealed()) { 408 return true; 409 } 410 for (var superinterface : clazz.getInterfaces()) { 411 if (superinterface.isSealed()) { 412 return true; 413 } 414 } 415 return false; 416 } 417 418 static String typeVarBounds(TypeVariable<?> typeVar) { 419 Type[] bounds = typeVar.getBounds(); 420 if (bounds.length == 1 && bounds[0].equals(Object.class)) { 421 return typeVar.getName(); 422 } else { 423 return typeVar.getName() + " extends " + 424 Arrays.stream(bounds) 425 .map(Type::getTypeName) 426 .collect(Collectors.joining(" & ")); 427 } 428 } 429 430 /** 431 * Returns the {@code Class} object associated with the class or 432 * interface with the given string name. Invoking this method is 433 * equivalent to: 434 * 435 * {@snippet lang="java" : 436 * Class.forName(className, true, currentLoader) 437 * } 438 * 439 * where {@code currentLoader} denotes the defining class loader of 440 * the current class. 441 * 442 * <p> For example, the following code fragment returns the 443 * runtime {@code Class} object for the class named 444 * {@code java.lang.Thread}: 445 * 446 * {@snippet lang="java" : 447 * Class<?> t = Class.forName("java.lang.Thread"); 448 * } 449 * <p> 450 * A call to {@code forName("X")} causes the class named 451 * {@code X} to be initialized. 452 * 453 * <p> 454 * In cases where this method is called from a context where there is no 455 * caller frame on the stack (e.g. when called directly from a JNI 456 * attached thread), the system class loader is used. 457 * 458 * @param className the {@linkplain ClassLoader##binary-name binary name} 459 * of the class or the string representing an array type 460 * @return the {@code Class} object for the class with the 461 * specified name. 462 * @throws LinkageError if the linkage fails 463 * @throws ExceptionInInitializerError if the initialization provoked 464 * by this method fails 465 * @throws ClassNotFoundException if the class cannot be located 466 * 467 * @jls 12.2 Loading of Classes and Interfaces 468 * @jls 12.3 Linking of Classes and Interfaces 469 * @jls 12.4 Initialization of Classes and Interfaces 470 */ 471 @CallerSensitive 472 public static Class<?> forName(String className) 473 throws ClassNotFoundException { 474 Class<?> caller = Reflection.getCallerClass(); 475 return forName(className, caller); 476 } 477 478 // Caller-sensitive adapter method for reflective invocation 479 @CallerSensitiveAdapter 480 private static Class<?> forName(String className, Class<?> caller) 481 throws ClassNotFoundException { 482 validateClassNameLength(className); 483 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader() 484 : ClassLoader.getClassLoader(caller); 485 return forName0(className, true, loader, caller); 486 } 487 488 /** 489 * Returns the {@code Class} object associated with the class or 490 * interface with the given string name, using the given class loader. 491 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface, 492 * this method attempts to locate and load the class or interface. The specified 493 * class loader is used to load the class or interface. If the parameter 494 * {@code loader} is {@code null}, the class is loaded through the bootstrap 495 * class loader. The class is initialized only if the 496 * {@code initialize} parameter is {@code true} and if it has 497 * not been initialized earlier. 498 * 499 * <p> This method cannot be used to obtain any of the {@code Class} objects 500 * representing primitive types or void, hidden classes or interfaces, 501 * or array classes whose element type is a hidden class or interface. 502 * If {@code name} denotes a primitive type or void, for example {@code I}, 503 * an attempt will be made to locate a user-defined class in the unnamed package 504 * whose name is {@code I} instead. 505 * To obtain a {@code Class} object for a named primitive type 506 * such as {@code int} or {@code long} use {@link 507 * #forPrimitiveName(String)}. 508 * 509 * <p> To obtain the {@code Class} object associated with an array class, 510 * the name consists of one or more {@code '['} representing the depth 511 * of the array nesting, followed by the element type as encoded in 512 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}. 513 * 514 * <p> Examples: 515 * {@snippet lang="java" : 516 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader); 517 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader); 518 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][] 519 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader); 520 * Class<?> fooClass = Class.forName("Foo", true, currentLoader); 521 * } 522 * 523 * <p> A call to {@code getName()} on the {@code Class} object returned 524 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>. 525 * 526 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type 527 * named <i>N</i> to be loaded but not initialized regardless of the value 528 * of the {@code initialize} parameter. 529 * 530 * @apiNote 531 * This method throws errors related to loading, linking or initializing 532 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of 533 * <cite>The Java Language Specification</cite>. 534 * In addition, this method does not check whether the requested class 535 * is accessible to its caller. 536 * 537 * @param name the {@linkplain ClassLoader##binary-name binary name} 538 * of the class or the string representing an array class 539 * 540 * @param initialize if {@code true} the class will be initialized 541 * (which implies linking). See Section {@jls 542 * 12.4} of <cite>The Java Language 543 * Specification</cite>. 544 * @param loader class loader from which the class must be loaded 545 * @return class object representing the desired class 546 * 547 * @throws LinkageError if the linkage fails 548 * @throws ExceptionInInitializerError if the initialization provoked 549 * by this method fails 550 * @throws ClassNotFoundException if the class cannot be located by 551 * the specified class loader 552 * 553 * @see java.lang.Class#forName(String) 554 * @see java.lang.ClassLoader 555 * 556 * @jls 12.2 Loading of Classes and Interfaces 557 * @jls 12.3 Linking of Classes and Interfaces 558 * @jls 12.4 Initialization of Classes and Interfaces 559 * @jls 13.1 The Form of a Binary 560 * @since 1.2 561 */ 562 public static Class<?> forName(String name, boolean initialize, ClassLoader loader) 563 throws ClassNotFoundException 564 { 565 validateClassNameLength(name); 566 return forName0(name, initialize, loader, null); 567 } 568 569 /** Called after security check for system loader access checks have been made. */ 570 private static native Class<?> forName0(String name, boolean initialize, 571 ClassLoader loader, 572 Class<?> caller) 573 throws ClassNotFoundException; 574 575 576 /** 577 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name 578 * binary name} in the given module. 579 * 580 * <p> This method attempts to locate and load the class or interface. 581 * It does not link the class, and does not run the class initializer. 582 * If the class is not found, this method returns {@code null}. </p> 583 * 584 * <p> If the class loader of the given module defines other modules and 585 * the given name is a class defined in a different module, this method 586 * returns {@code null} after the class is loaded. </p> 587 * 588 * <p> This method does not check whether the requested class is 589 * accessible to its caller. </p> 590 * 591 * @apiNote 592 * This method does not support loading of array types, unlike 593 * {@link #forName(String, boolean, ClassLoader)}. The class name must be 594 * a binary name. This method returns {@code null} on failure rather than 595 * throwing a {@link ClassNotFoundException}, as is done by 596 * the {@link #forName(String, boolean, ClassLoader)} method. 597 * 598 * @param module A module 599 * @param name The {@linkplain ClassLoader##binary-name binary name} 600 * of the class 601 * @return {@code Class} object of the given name defined in the given module; 602 * {@code null} if not found. 603 * 604 * @throws NullPointerException if the given module or name is {@code null} 605 * 606 * @throws LinkageError if the linkage fails 607 * 608 * @jls 12.2 Loading of Classes and Interfaces 609 * @jls 12.3 Linking of Classes and Interfaces 610 * @since 9 611 */ 612 public static Class<?> forName(Module module, String name) { 613 Objects.requireNonNull(module); 614 Objects.requireNonNull(name); 615 if (!ModifiedUtf.isValidLengthInConstantPool(name)) { 616 return null; 617 } 618 619 ClassLoader cl = module.getClassLoader(); 620 if (cl != null) { 621 return cl.loadClass(module, name); 622 } else { 623 return BootLoader.loadClass(module, name); 624 } 625 } 626 627 /** 628 * {@return {@code true} if this {@code Class} object represents an identity class, 629 * otherwise {@code false}} 630 * 631 * <ul> 632 * <li> 633 * If this {@code Class} object represents an array type this method returns {@code true}. 634 * <li> 635 * If this {@code Class} object represents an interface, a primitive type, 636 * or {@code void} this method returns {@code false}. 637 * <li> 638 * For all other {@code Class} objects, this method returns {@code true} if either 639 * preview features are disabled or {@linkplain Modifier#IDENTITY} is set in the 640 * {@linkplain #getModifiers() class modifiers}. 641 * </ul> 642 * @see AccessFlag#IDENTITY 643 * @since Valhalla 644 */ 645 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true) 646 public boolean isIdentity() { 647 if (isPrimitive()) { 648 return false; 649 } else if (PreviewFeatures.isEnabled()) { 650 return isArray() || Modifier.isIdentity(modifiers); 651 } else { 652 return !isInterface(); 653 } 654 } 655 656 /** 657 * {@return {@code true} if this {@code Class} object represents a value class, 658 * otherwise {@code false}} 659 * <ul> 660 * <li> 661 * If this {@code Class} object represents an array type this method returns {@code false}. 662 * <li> 663 * If this {@code Class} object represents an interface, a primitive type, 664 * or {@code void} this method returns {@code true} only if preview features are enabled. 665 * <li> 666 * For all other {@code Class} objects, this method returns {@code true} only if 667 * preview features are enabled and {@linkplain Modifier#IDENTITY} is not set in the 668 * {@linkplain #getModifiers() class modifiers}. 669 * </ul> 670 * @see AccessFlag#IDENTITY 671 * @since Valhalla 672 */ 673 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true) 674 public boolean isValue() { 675 if (!PreviewFeatures.isEnabled()) { 676 return false; 677 } 678 return !isIdentity(); 679 } 680 681 /** 682 * {@return the {@code Class} object associated with the 683 * {@linkplain #isPrimitive() primitive type} of the given name} 684 * If the argument is not the name of a primitive type, {@code 685 * null} is returned. 686 * 687 * @param primitiveName the name of the primitive type to find 688 * 689 * @throws NullPointerException if the argument is {@code null} 690 * 691 * @jls 4.2 Primitive Types and Values 692 * @jls 15.8.2 Class Literals 693 * @since 22 694 */ 695 public static Class<?> forPrimitiveName(String primitiveName) { 696 return switch(primitiveName) { 697 // Integral types 698 case "int" -> int.class; 699 case "long" -> long.class; 700 case "short" -> short.class; 701 case "char" -> char.class; 702 case "byte" -> byte.class; 703 704 // Floating-point types 705 case "float" -> float.class; 706 case "double" -> double.class; 707 708 // Other types 709 case "boolean" -> boolean.class; 710 case "void" -> void.class; 711 712 default -> null; 713 }; 714 } 715 716 /** 717 * Creates a new instance of the class represented by this {@code Class} 718 * object. The class is instantiated as if by a {@code new} 719 * expression with an empty argument list. The class is initialized if it 720 * has not already been initialized. 721 * 722 * @deprecated This method propagates any exception thrown by the 723 * nullary constructor, including a checked exception. Use of 724 * this method effectively bypasses the compile-time exception 725 * checking that would otherwise be performed by the compiler. 726 * The {@link 727 * java.lang.reflect.Constructor#newInstance(java.lang.Object...) 728 * Constructor.newInstance} method avoids this problem by wrapping 729 * any exception thrown by the constructor in a (checked) {@link 730 * java.lang.reflect.InvocationTargetException}. 731 * 732 * <p>The call 733 * 734 * {@snippet lang="java" : 735 * clazz.newInstance() 736 * } 737 * 738 * can be replaced by 739 * 740 * {@snippet lang="java" : 741 * clazz.getDeclaredConstructor().newInstance() 742 * } 743 * 744 * The latter sequence of calls is inferred to be able to throw 745 * the additional exception types {@link 746 * InvocationTargetException} and {@link 747 * NoSuchMethodException}. Both of these exception types are 748 * subclasses of {@link ReflectiveOperationException}. 749 * 750 * @return a newly allocated instance of the class represented by this 751 * object. 752 * @throws IllegalAccessException if the class or its nullary 753 * constructor is not accessible. 754 * @throws InstantiationException 755 * if this {@code Class} represents an abstract class, 756 * an interface, an array class, a primitive type, or void; 757 * or if the class has no nullary constructor; 758 * or if the instantiation fails for some other reason. 759 * @throws ExceptionInInitializerError if the initialization 760 * provoked by this method fails. 761 */ 762 @CallerSensitive 763 @Deprecated(since="9") 764 public T newInstance() 765 throws InstantiationException, IllegalAccessException 766 { 767 // Constructor lookup 768 Constructor<T> tmpConstructor = cachedConstructor; 769 if (tmpConstructor == null) { 770 if (this == Class.class) { 771 throw new IllegalAccessException( 772 "Can not call newInstance() on the Class for java.lang.Class" 773 ); 774 } 775 try { 776 Class<?>[] empty = {}; 777 final Constructor<T> c = getReflectionFactory().copyConstructor( 778 getConstructor0(empty, Member.DECLARED)); 779 // Disable accessibility checks on the constructor 780 // access check is done with the true caller 781 c.setAccessible(true); 782 cachedConstructor = tmpConstructor = c; 783 } catch (NoSuchMethodException e) { 784 throw (InstantiationException) 785 new InstantiationException(getName()).initCause(e); 786 } 787 } 788 789 try { 790 Class<?> caller = Reflection.getCallerClass(); 791 return getReflectionFactory().newInstance(tmpConstructor, null, caller); 792 } catch (InvocationTargetException e) { 793 Unsafe.getUnsafe().throwException(e.getTargetException()); 794 // Not reached 795 return null; 796 } 797 } 798 799 private transient volatile Constructor<T> cachedConstructor; 800 801 /** 802 * Determines if the specified {@code Object} is assignment-compatible 803 * with the object represented by this {@code Class}. This method is 804 * the dynamic equivalent of the Java language {@code instanceof} 805 * operator. The method returns {@code true} if the specified 806 * {@code Object} argument is non-null and can be cast to the 807 * reference type represented by this {@code Class} object without 808 * raising a {@code ClassCastException.} It returns {@code false} 809 * otherwise. 810 * 811 * <p> Specifically, if this {@code Class} object represents a 812 * declared class, this method returns {@code true} if the specified 813 * {@code Object} argument is an instance of the represented class (or 814 * of any of its subclasses); it returns {@code false} otherwise. If 815 * this {@code Class} object represents an array class, this method 816 * returns {@code true} if the specified {@code Object} argument 817 * can be converted to an object of the array class by an identity 818 * conversion or by a widening reference conversion; it returns 819 * {@code false} otherwise. If this {@code Class} object 820 * represents an interface, this method returns {@code true} if the 821 * class or any superclass of the specified {@code Object} argument 822 * implements this interface; it returns {@code false} otherwise. If 823 * this {@code Class} object represents a primitive type, this method 824 * returns {@code false}. 825 * 826 * @param obj the object to check 827 * @return true if {@code obj} is an instance of this class 828 * 829 * @since 1.1 830 */ 831 @IntrinsicCandidate 832 public native boolean isInstance(Object obj); 833 834 835 /** 836 * Determines if the class or interface represented by this 837 * {@code Class} object is either the same as, or is a superclass or 838 * superinterface of, the class or interface represented by the specified 839 * {@code Class} parameter. It returns {@code true} if so; 840 * otherwise it returns {@code false}. If this {@code Class} 841 * object represents a primitive type, this method returns 842 * {@code true} if the specified {@code Class} parameter is 843 * exactly this {@code Class} object; otherwise it returns 844 * {@code false}. 845 * 846 * <p> Specifically, this method tests whether the type represented by the 847 * specified {@code Class} parameter can be converted to the type 848 * represented by this {@code Class} object via an identity conversion 849 * or via a widening reference conversion. See <cite>The Java Language 850 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4}, 851 * for details. 852 * 853 * @param cls the {@code Class} object to be checked 854 * @return the {@code boolean} value indicating whether objects of the 855 * type {@code cls} can be assigned to objects of this class 856 * @throws NullPointerException if the specified Class parameter is 857 * null. 858 * @since 1.1 859 */ 860 @IntrinsicCandidate 861 public native boolean isAssignableFrom(Class<?> cls); 862 863 864 /** 865 * Determines if this {@code Class} object represents an 866 * interface type. 867 * 868 * @return {@code true} if this {@code Class} object represents an interface; 869 * {@code false} otherwise. 870 */ 871 public boolean isInterface() { 872 return Modifier.isInterface(modifiers); 873 } 874 875 876 /** 877 * Determines if this {@code Class} object represents an array class. 878 * 879 * @return {@code true} if this {@code Class} object represents an array class; 880 * {@code false} otherwise. 881 * @since 1.1 882 */ 883 public boolean isArray() { 884 return componentType != null; 885 } 886 887 888 /** 889 * Determines if this {@code Class} object represents a primitive 890 * type or void. 891 * 892 * <p> There are nine predefined {@code Class} objects to 893 * represent the eight primitive types and void. These are 894 * created by the Java Virtual Machine, and have the same 895 * {@linkplain #getName() names} as the primitive types that they 896 * represent, namely {@code boolean}, {@code byte}, {@code char}, 897 * {@code short}, {@code int}, {@code long}, {@code float}, and 898 * {@code double}. 899 * 900 * <p>No other class objects are considered primitive. 901 * 902 * @apiNote 903 * A {@code Class} object represented by a primitive type can be 904 * accessed via the {@code TYPE} public static final variables 905 * defined in the primitive wrapper classes such as {@link 906 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming 907 * language, the objects may be referred to by a class literal 908 * expression such as {@code int.class}. The {@code Class} object 909 * for void can be expressed as {@code void.class} or {@link 910 * java.lang.Void#TYPE Void.TYPE}. 911 * 912 * @return true if and only if this class represents a primitive type 913 * 914 * @see java.lang.Boolean#TYPE 915 * @see java.lang.Character#TYPE 916 * @see java.lang.Byte#TYPE 917 * @see java.lang.Short#TYPE 918 * @see java.lang.Integer#TYPE 919 * @see java.lang.Long#TYPE 920 * @see java.lang.Float#TYPE 921 * @see java.lang.Double#TYPE 922 * @see java.lang.Void#TYPE 923 * @since 1.1 924 * @jls 15.8.2 Class Literals 925 */ 926 public boolean isPrimitive() { 927 return primitive; 928 } 929 930 /** 931 * Returns true if this {@code Class} object represents an annotation 932 * interface. Note that if this method returns true, {@link #isInterface()} 933 * would also return true, as all annotation interfaces are also interfaces. 934 * 935 * @return {@code true} if this {@code Class} object represents an annotation 936 * interface; {@code false} otherwise 937 * @since 1.5 938 */ 939 public boolean isAnnotation() { 940 return (getModifiers() & ANNOTATION) != 0; 941 } 942 943 /** 944 *{@return {@code true} if and only if this class has the synthetic modifier 945 * bit set} 946 * 947 * @jls 13.1 The Form of a Binary 948 * @jvms 4.1 The {@code ClassFile} Structure 949 * @see <a 950 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java 951 * programming language and JVM modeling in core reflection</a> 952 * @since 1.5 953 */ 954 public boolean isSynthetic() { 955 return (getModifiers() & SYNTHETIC) != 0; 956 } 957 958 /** 959 * Returns the name of the entity (class, interface, array class, 960 * primitive type, or void) represented by this {@code Class} object. 961 * 962 * <p> If this {@code Class} object represents a class or interface, 963 * not an array class, then: 964 * <ul> 965 * <li> If the class or interface is not {@linkplain #isHidden() hidden}, 966 * then the {@linkplain ClassLoader##binary-name binary name} 967 * of the class or interface is returned. 968 * <li> If the class or interface is hidden, then the result is a string 969 * of the form: {@code N + '/' + <suffix>} 970 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name} 971 * indicated by the {@code class} file passed to 972 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 973 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name. 974 * </ul> 975 * 976 * <p> If this {@code Class} object represents an array class, then 977 * the result is a string consisting of one or more '{@code [}' characters 978 * representing the depth of the array nesting, followed by the element 979 * type as encoded using the following table: 980 * 981 * <blockquote><table class="striped" id="nameFormat"> 982 * <caption style="display:none">Element types and encodings</caption> 983 * <thead> 984 * <tr><th scope="col"> Element Type <th scope="col"> Encoding 985 * </thead> 986 * <tbody style="text-align:left"> 987 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z} 988 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B} 989 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C} 990 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i> 991 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;} 992 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D} 993 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F} 994 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I} 995 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J} 996 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S} 997 * </tbody> 998 * </table></blockquote> 999 * 1000 * <p> If this {@code Class} object represents a primitive type or {@code void}, 1001 * then the result is a string with the same spelling as the Java language 1002 * keyword which corresponds to the primitive type or {@code void}. 1003 * 1004 * <p> Examples: 1005 * <blockquote><pre> 1006 * String.class.getName() 1007 * returns "java.lang.String" 1008 * Character.UnicodeBlock.class.getName() 1009 * returns "java.lang.Character$UnicodeBlock" 1010 * byte.class.getName() 1011 * returns "byte" 1012 * (new Object[3]).getClass().getName() 1013 * returns "[Ljava.lang.Object;" 1014 * (new int[3][4][5][6][7][8][9]).getClass().getName() 1015 * returns "[[[[[[[I" 1016 * </pre></blockquote> 1017 * 1018 * @apiNote 1019 * Distinct class objects can have the same name but different class loaders. 1020 * 1021 * @return the name of the class, interface, or other entity 1022 * represented by this {@code Class} object. 1023 * @jls 13.1 The Form of a Binary 1024 */ 1025 public String getName() { 1026 String name = this.name; 1027 return name != null ? name : initClassName(); 1028 } 1029 1030 // Cache the name to reduce the number of calls into the VM. 1031 // This field would be set by VM itself during initClassName call. 1032 private transient String name; 1033 private native String initClassName(); 1034 1035 /** 1036 * Returns the class loader for the class. Some implementations may use 1037 * null to represent the bootstrap class loader. This method will return 1038 * null in such implementations if this class was loaded by the bootstrap 1039 * class loader. 1040 * 1041 * <p>If this {@code Class} object 1042 * represents a primitive type or void, null is returned. 1043 * 1044 * @return the class loader that loaded the class or interface 1045 * represented by this {@code Class} object. 1046 * @see java.lang.ClassLoader 1047 */ 1048 public ClassLoader getClassLoader() { 1049 return classLoader; 1050 } 1051 1052 // Package-private to allow ClassLoader access 1053 ClassLoader getClassLoader0() { return classLoader; } 1054 1055 /** 1056 * Returns the module that this class or interface is a member of. 1057 * 1058 * If this class represents an array type then this method returns the 1059 * {@code Module} for the element type. If this class represents a 1060 * primitive type or void, then the {@code Module} object for the 1061 * {@code java.base} module is returned. 1062 * 1063 * If this class is in an unnamed module then the {@linkplain 1064 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class 1065 * loader for this class is returned. 1066 * 1067 * @return the module that this class or interface is a member of 1068 * 1069 * @since 9 1070 */ 1071 public Module getModule() { 1072 return module; 1073 } 1074 1075 // set by VM 1076 @Stable 1077 private transient Module module; 1078 1079 // Initialized in JVM not by private constructor 1080 // This field is filtered from reflection access, i.e. getDeclaredField 1081 // will throw NoSuchFieldException 1082 private final ClassLoader classLoader; 1083 1084 private transient Object classData; // Set by VM 1085 private transient Object[] signers; // Read by VM, mutable 1086 private final transient char modifiers; // Set by the VM 1087 private final transient char classFileAccessFlags; // Set by the VM 1088 private final transient boolean primitive; // Set by the VM if the Class is a primitive type. 1089 1090 // package-private 1091 Object getClassData() { 1092 return classData; 1093 } 1094 1095 /** 1096 * Returns an array of {@code TypeVariable} objects that represent the 1097 * type variables declared by the generic declaration represented by this 1098 * {@code GenericDeclaration} object, in declaration order. Returns an 1099 * array of length 0 if the underlying generic declaration declares no type 1100 * variables. 1101 * 1102 * @return an array of {@code TypeVariable} objects that represent 1103 * the type variables declared by this generic declaration 1104 * @throws java.lang.reflect.GenericSignatureFormatError if the generic 1105 * signature of this generic declaration does not conform to 1106 * the format specified in section {@jvms 4.7.9} of 1107 * <cite>The Java Virtual Machine Specification</cite> 1108 * @since 1.5 1109 */ 1110 @SuppressWarnings("unchecked") 1111 public TypeVariable<Class<T>>[] getTypeParameters() { 1112 ClassRepository info = getGenericInfo(); 1113 if (info != null) 1114 return (TypeVariable<Class<T>>[])info.getTypeParameters(); 1115 else 1116 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0]; 1117 } 1118 1119 1120 /** 1121 * Returns the {@code Class} representing the direct superclass of the 1122 * entity (class, interface, primitive type or void) represented by 1123 * this {@code Class}. If this {@code Class} represents either the 1124 * {@code Object} class, an interface, a primitive type, or void, then 1125 * null is returned. If this {@code Class} object represents an array class 1126 * then the {@code Class} object representing the {@code Object} class is 1127 * returned. 1128 * 1129 * @return the direct superclass of the class represented by this {@code Class} object 1130 */ 1131 @IntrinsicCandidate 1132 public native Class<? super T> getSuperclass(); 1133 1134 1135 /** 1136 * Returns the {@code Type} representing the direct superclass of 1137 * the entity (class, interface, primitive type or void) represented by 1138 * this {@code Class} object. 1139 * 1140 * <p>If the superclass is a parameterized type, the {@code Type} 1141 * object returned must accurately reflect the actual type 1142 * arguments used in the source code. The parameterized type 1143 * representing the superclass is created if it had not been 1144 * created before. See the declaration of {@link 1145 * java.lang.reflect.ParameterizedType ParameterizedType} for the 1146 * semantics of the creation process for parameterized types. If 1147 * this {@code Class} object represents either the {@code Object} 1148 * class, an interface, a primitive type, or void, then null is 1149 * returned. If this {@code Class} object represents an array class 1150 * then the {@code Class} object representing the {@code Object} class is 1151 * returned. 1152 * 1153 * @throws java.lang.reflect.GenericSignatureFormatError if the generic 1154 * class signature does not conform to the format specified in 1155 * section {@jvms 4.7.9} of <cite>The Java Virtual 1156 * Machine Specification</cite> 1157 * @throws TypeNotPresentException if the generic superclass 1158 * refers to a non-existent type declaration 1159 * @throws java.lang.reflect.MalformedParameterizedTypeException if the 1160 * generic superclass refers to a parameterized type that cannot be 1161 * instantiated for any reason 1162 * @return the direct superclass of the class represented by this {@code Class} object 1163 * @since 1.5 1164 */ 1165 public Type getGenericSuperclass() { 1166 ClassRepository info = getGenericInfo(); 1167 if (info == null) { 1168 return getSuperclass(); 1169 } 1170 1171 // Historical irregularity: 1172 // Generic signature marks interfaces with superclass = Object 1173 // but this API returns null for interfaces 1174 if (isInterface()) { 1175 return null; 1176 } 1177 1178 return info.getSuperclass(); 1179 } 1180 1181 /** 1182 * Gets the package of this class. 1183 * 1184 * <p>If this class represents an array type, a primitive type or void, 1185 * this method returns {@code null}. 1186 * 1187 * @return the package of this class. 1188 */ 1189 public Package getPackage() { 1190 if (isPrimitive() || isArray()) { 1191 return null; 1192 } 1193 ClassLoader cl = classLoader; 1194 return cl != null ? cl.definePackage(this) 1195 : BootLoader.definePackage(this); 1196 } 1197 1198 /** 1199 * Returns the fully qualified package name. 1200 * 1201 * <p> If this class is a top level class, then this method returns the fully 1202 * qualified name of the package that the class is a member of, or the 1203 * empty string if the class is in an unnamed package. 1204 * 1205 * <p> If this class is a member class, then this method is equivalent to 1206 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass 1207 * enclosing class}. 1208 * 1209 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain 1210 * #isAnonymousClass() anonymous class}, then this method is equivalent to 1211 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass 1212 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or 1213 * {@linkplain #getEnclosingConstructor enclosing constructor}. 1214 * 1215 * <p> If this class represents an array type then this method returns the 1216 * package name of the element type. If this class represents a primitive 1217 * type or void then the package name "{@code java.lang}" is returned. 1218 * 1219 * @return the fully qualified package name 1220 * 1221 * @since 9 1222 * @jls 6.7 Fully Qualified Names and Canonical Names 1223 */ 1224 public String getPackageName() { 1225 String pn = this.packageName; 1226 if (pn == null) { 1227 Class<?> c = isArray() ? elementType() : this; 1228 if (c.isPrimitive()) { 1229 pn = "java.lang"; 1230 } else { 1231 String cn = c.getName(); 1232 int dot = cn.lastIndexOf('.'); 1233 pn = (dot != -1) ? cn.substring(0, dot).intern() : ""; 1234 } 1235 this.packageName = pn; 1236 } 1237 return pn; 1238 } 1239 1240 // cached package name 1241 private transient String packageName; 1242 1243 /** 1244 * Returns the interfaces directly implemented by the class or interface 1245 * represented by this {@code Class} object. 1246 * 1247 * <p>If this {@code Class} object represents a class, the return value is an array 1248 * containing objects representing all interfaces directly implemented by 1249 * the class. The order of the interface objects in the array corresponds 1250 * to the order of the interface names in the {@code implements} clause of 1251 * the declaration of the class represented by this {@code Class} object. For example, 1252 * given the declaration: 1253 * <blockquote> 1254 * {@code class Shimmer implements FloorWax, DessertTopping { ... }} 1255 * </blockquote> 1256 * suppose the value of {@code s} is an instance of 1257 * {@code Shimmer}; the value of the expression: 1258 * <blockquote> 1259 * {@code s.getClass().getInterfaces()[0]} 1260 * </blockquote> 1261 * is the {@code Class} object that represents interface 1262 * {@code FloorWax}; and the value of: 1263 * <blockquote> 1264 * {@code s.getClass().getInterfaces()[1]} 1265 * </blockquote> 1266 * is the {@code Class} object that represents interface 1267 * {@code DessertTopping}. 1268 * 1269 * <p>If this {@code Class} object represents an interface, the array contains objects 1270 * representing all interfaces directly extended by the interface. The 1271 * order of the interface objects in the array corresponds to the order of 1272 * the interface names in the {@code extends} clause of the declaration of 1273 * the interface represented by this {@code Class} object. 1274 * 1275 * <p>If this {@code Class} object represents a class or interface that implements no 1276 * interfaces, the method returns an array of length 0. 1277 * 1278 * <p>If this {@code Class} object represents a primitive type or void, the method 1279 * returns an array of length 0. 1280 * 1281 * <p>If this {@code Class} object represents an array type, the 1282 * interfaces {@code Cloneable} and {@code java.io.Serializable} are 1283 * returned in that order. 1284 * 1285 * @return an array of interfaces directly implemented by this class 1286 */ 1287 public Class<?>[] getInterfaces() { 1288 // defensively copy before handing over to user code 1289 return getInterfaces(true); 1290 } 1291 1292 private Class<?>[] getInterfaces(boolean cloneArray) { 1293 ReflectionData<T> rd = reflectionData(); 1294 Class<?>[] interfaces = rd.interfaces; 1295 if (interfaces == null) { 1296 interfaces = getInterfaces0(); 1297 rd.interfaces = interfaces; 1298 } 1299 // defensively copy if requested 1300 return cloneArray ? interfaces.clone() : interfaces; 1301 } 1302 1303 private native Class<?>[] getInterfaces0(); 1304 1305 /** 1306 * Returns the {@code Type}s representing the interfaces 1307 * directly implemented by the class or interface represented by 1308 * this {@code Class} object. 1309 * 1310 * <p>If a superinterface is a parameterized type, the 1311 * {@code Type} object returned for it must accurately reflect 1312 * the actual type arguments used in the source code. The 1313 * parameterized type representing each superinterface is created 1314 * if it had not been created before. See the declaration of 1315 * {@link java.lang.reflect.ParameterizedType ParameterizedType} 1316 * for the semantics of the creation process for parameterized 1317 * types. 1318 * 1319 * <p>If this {@code Class} object represents a class, the return value is an array 1320 * containing objects representing all interfaces directly implemented by 1321 * the class. The order of the interface objects in the array corresponds 1322 * to the order of the interface names in the {@code implements} clause of 1323 * the declaration of the class represented by this {@code Class} object. 1324 * 1325 * <p>If this {@code Class} object represents an interface, the array contains objects 1326 * representing all interfaces directly extended by the interface. The 1327 * order of the interface objects in the array corresponds to the order of 1328 * the interface names in the {@code extends} clause of the declaration of 1329 * the interface represented by this {@code Class} object. 1330 * 1331 * <p>If this {@code Class} object represents a class or interface that implements no 1332 * interfaces, the method returns an array of length 0. 1333 * 1334 * <p>If this {@code Class} object represents a primitive type or void, the method 1335 * returns an array of length 0. 1336 * 1337 * <p>If this {@code Class} object represents an array type, the 1338 * interfaces {@code Cloneable} and {@code java.io.Serializable} are 1339 * returned in that order. 1340 * 1341 * @throws java.lang.reflect.GenericSignatureFormatError 1342 * if the generic class signature does not conform to the 1343 * format specified in section {@jvms 4.7.9} of <cite>The 1344 * Java Virtual Machine Specification</cite> 1345 * @throws TypeNotPresentException if any of the generic 1346 * superinterfaces refers to a non-existent type declaration 1347 * @throws java.lang.reflect.MalformedParameterizedTypeException 1348 * if any of the generic superinterfaces refer to a parameterized 1349 * type that cannot be instantiated for any reason 1350 * @return an array of interfaces directly implemented by this class 1351 * @since 1.5 1352 */ 1353 public Type[] getGenericInterfaces() { 1354 ClassRepository info = getGenericInfo(); 1355 return (info == null) ? getInterfaces() : info.getSuperInterfaces(); 1356 } 1357 1358 1359 /** 1360 * Returns the {@code Class} representing the component type of an 1361 * array. If this class does not represent an array class this method 1362 * returns null. 1363 * 1364 * @return the {@code Class} representing the component type of this 1365 * class if this class is an array 1366 * @see java.lang.reflect.Array 1367 * @since 1.1 1368 */ 1369 public Class<?> getComponentType() { 1370 return componentType; 1371 } 1372 1373 // The componentType field's null value is the sole indication that the class 1374 // is an array - see isArray(). 1375 private transient final Class<?> componentType; 1376 1377 /* 1378 * Returns the {@code Class} representing the element type of an array class. 1379 * If this class does not represent an array class, then this method returns 1380 * {@code null}. 1381 */ 1382 private Class<?> elementType() { 1383 if (!isArray()) return null; 1384 1385 Class<?> c = this; 1386 while (c.isArray()) { 1387 c = c.getComponentType(); 1388 } 1389 return c; 1390 } 1391 1392 /** 1393 * Returns the Java language modifiers for this class or interface, encoded 1394 * in an integer. The modifiers consist of the Java Virtual Machine's 1395 * constants for {@code public}, {@code protected}, 1396 * {@code private}, {@code final}, {@code static}, 1397 * {@code abstract} and {@code interface}; they should be decoded 1398 * using the methods of class {@code Modifier}. 1399 * 1400 * <p> If the underlying class is an array class: 1401 * <ul> 1402 * <li> its {@code public}, {@code private} and {@code protected} 1403 * modifiers are the same as those of its component type 1404 * <li> its {@code abstract} and {@code final} modifiers are always 1405 * {@code true} 1406 * <li> its interface modifier is always {@code false}, even when 1407 * the component type is an interface 1408 * <li> its {@code identity} modifier is always true 1409 * </ul> 1410 * If this {@code Class} object represents a primitive type or 1411 * void, its {@code public}, {@code abstract}, and {@code final} 1412 * modifiers are always {@code true}. 1413 * For {@code Class} objects representing void, primitive types, and 1414 * arrays, the values of other modifiers are {@code false} other 1415 * than as specified above. 1416 * 1417 * <p> The modifier encodings are defined in section {@jvms 4.1} 1418 * of <cite>The Java Virtual Machine Specification</cite>. 1419 * 1420 * @return the {@code int} representing the modifiers for this class 1421 * @see java.lang.reflect.Modifier 1422 * @see #accessFlags() 1423 * @see <a 1424 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java 1425 * programming language and JVM modeling in core reflection</a> 1426 * @since 1.1 1427 * @jls 8.1.1 Class Modifiers 1428 * @jls 9.1.1 Interface Modifiers 1429 * @jvms 4.1 The {@code ClassFile} Structure 1430 */ 1431 public int getModifiers() { return modifiers; } 1432 1433 /** 1434 * {@return an unmodifiable set of the {@linkplain AccessFlag access 1435 * flags} for this class, possibly empty} 1436 * The {@code AccessFlags} may depend on the class file format version of the class. 1437 * 1438 * <p> If the underlying class is an array class: 1439 * <ul> 1440 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED} 1441 * access flags are the same as those of its component type 1442 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present 1443 * <li> its {@code INTERFACE} flag is absent, even when the 1444 * component type is an interface 1445 * <li> its {@code identity} modifier is always true 1446 * </ul> 1447 * If this {@code Class} object represents a primitive type or 1448 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and 1449 * {@code FINAL}. 1450 * For {@code Class} objects representing void, primitive types, and 1451 * arrays, access flags are absent other than as specified above. 1452 * 1453 * @see #getModifiers() 1454 * @jvms 4.1 The ClassFile Structure 1455 * @jvms 4.7.6 The InnerClasses Attribute 1456 * @since 20 1457 */ 1458 public Set<AccessFlag> accessFlags() { 1459 // Location.CLASS allows SUPER and AccessFlag.MODULE which 1460 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED, 1461 // and STATIC, which are not allowed on Location.CLASS. 1462 // Use getClassFileAccessFlags to expose SUPER status. 1463 // Arrays need to use PRIVATE/PROTECTED from its component modifiers. 1464 var location = (isMemberClass() || isLocalClass() || 1465 isAnonymousClass() || isArray()) ? 1466 AccessFlag.Location.INNER_CLASS : 1467 AccessFlag.Location.CLASS; 1468 int accessFlags = location == AccessFlag.Location.CLASS ? getClassFileAccessFlags() : getModifiers(); 1469 var reflectionFactory = getReflectionFactory(); 1470 var ans = reflectionFactory.parseAccessFlags(accessFlags, location, this); 1471 if (PreviewFeatures.isEnabled() && reflectionFactory.classFileFormatVersion(this) != ClassFileFormatVersion.CURRENT_PREVIEW_FEATURES 1472 && isIdentity()) { 1473 var set = new HashSet<>(ans); 1474 set.add(AccessFlag.IDENTITY); 1475 return Set.copyOf(set); 1476 } 1477 return ans; 1478 } 1479 1480 /** 1481 * Gets the signers of this class. 1482 * 1483 * @return the signers of this class, or null if there are no signers. In 1484 * particular, this method returns null if this {@code Class} object represents 1485 * a primitive type or void. 1486 * @since 1.1 1487 */ 1488 1489 public Object[] getSigners() { 1490 var signers = this.signers; 1491 return signers == null ? null : signers.clone(); 1492 } 1493 1494 /** 1495 * Set the signers of this class. 1496 */ 1497 void setSigners(Object[] signers) { 1498 if (!isPrimitive() && !isArray()) { 1499 this.signers = signers; 1500 } 1501 } 1502 1503 /** 1504 * If this {@code Class} object represents a local or anonymous 1505 * class within a method, returns a {@link 1506 * java.lang.reflect.Method Method} object representing the 1507 * immediately enclosing method of the underlying class. Returns 1508 * {@code null} otherwise. 1509 * 1510 * In particular, this method returns {@code null} if the underlying 1511 * class is a local or anonymous class immediately enclosed by a class or 1512 * interface declaration, instance initializer or static initializer. 1513 * 1514 * @return the immediately enclosing method of the underlying class, if 1515 * that class is a local or anonymous class; otherwise {@code null}. 1516 * 1517 * @since 1.5 1518 */ 1519 public Method getEnclosingMethod() { 1520 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo(); 1521 1522 if (enclosingInfo == null) 1523 return null; 1524 else { 1525 if (!enclosingInfo.isMethod()) 1526 return null; 1527 1528 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(), 1529 getFactory()); 1530 Class<?> returnType = toClass(typeInfo.getReturnType()); 1531 Type [] parameterTypes = typeInfo.getParameterTypes(); 1532 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length]; 1533 1534 // Convert Types to Classes; returned types *should* 1535 // be class objects since the methodDescriptor's used 1536 // don't have generics information 1537 for(int i = 0; i < parameterClasses.length; i++) 1538 parameterClasses[i] = toClass(parameterTypes[i]); 1539 1540 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass(); 1541 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false); 1542 1543 /* 1544 * Loop over all declared methods; match method name, 1545 * number of and type of parameters, *and* return 1546 * type. Matching return type is also necessary 1547 * because of covariant returns, etc. 1548 */ 1549 ReflectionFactory fact = getReflectionFactory(); 1550 for (Method m : candidates) { 1551 if (m.getName().equals(enclosingInfo.getName()) && 1552 arrayContentsEq(parameterClasses, 1553 fact.getExecutableSharedParameterTypes(m))) { 1554 // finally, check return type 1555 if (m.getReturnType().equals(returnType)) { 1556 return fact.copyMethod(m); 1557 } 1558 } 1559 } 1560 1561 throw new InternalError("Enclosing method not found"); 1562 } 1563 } 1564 1565 private native Object[] getEnclosingMethod0(); 1566 1567 private EnclosingMethodInfo getEnclosingMethodInfo() { 1568 Object[] enclosingInfo = getEnclosingMethod0(); 1569 if (enclosingInfo == null) 1570 return null; 1571 else { 1572 return new EnclosingMethodInfo(enclosingInfo); 1573 } 1574 } 1575 1576 private static final class EnclosingMethodInfo { 1577 private final Class<?> enclosingClass; 1578 private final String name; 1579 private final String descriptor; 1580 1581 static void validate(Object[] enclosingInfo) { 1582 if (enclosingInfo.length != 3) 1583 throw new InternalError("Malformed enclosing method information"); 1584 try { 1585 // The array is expected to have three elements: 1586 1587 // the immediately enclosing class 1588 Class<?> enclosingClass = (Class<?>)enclosingInfo[0]; 1589 assert(enclosingClass != null); 1590 1591 // the immediately enclosing method or constructor's 1592 // name (can be null). 1593 String name = (String)enclosingInfo[1]; 1594 1595 // the immediately enclosing method or constructor's 1596 // descriptor (null iff name is). 1597 String descriptor = (String)enclosingInfo[2]; 1598 assert((name != null && descriptor != null) || name == descriptor); 1599 } catch (ClassCastException cce) { 1600 throw new InternalError("Invalid type in enclosing method information", cce); 1601 } 1602 } 1603 1604 EnclosingMethodInfo(Object[] enclosingInfo) { 1605 validate(enclosingInfo); 1606 this.enclosingClass = (Class<?>)enclosingInfo[0]; 1607 this.name = (String)enclosingInfo[1]; 1608 this.descriptor = (String)enclosingInfo[2]; 1609 } 1610 1611 boolean isPartial() { 1612 return enclosingClass == null || name == null || descriptor == null; 1613 } 1614 1615 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); } 1616 1617 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); } 1618 1619 Class<?> getEnclosingClass() { return enclosingClass; } 1620 1621 String getName() { return name; } 1622 1623 String getDescriptor() { return descriptor; } 1624 1625 } 1626 1627 private static Class<?> toClass(Type o) { 1628 if (o instanceof GenericArrayType gat) 1629 return toClass(gat.getGenericComponentType()).arrayType(); 1630 return (Class<?>)o; 1631 } 1632 1633 /** 1634 * If this {@code Class} object represents a local or anonymous 1635 * class within a constructor, returns a {@link 1636 * java.lang.reflect.Constructor Constructor} object representing 1637 * the immediately enclosing constructor of the underlying 1638 * class. Returns {@code null} otherwise. In particular, this 1639 * method returns {@code null} if the underlying class is a local 1640 * or anonymous class immediately enclosed by a class or 1641 * interface declaration, instance initializer or static initializer. 1642 * 1643 * @return the immediately enclosing constructor of the underlying class, if 1644 * that class is a local or anonymous class; otherwise {@code null}. 1645 * 1646 * @since 1.5 1647 */ 1648 public Constructor<?> getEnclosingConstructor() { 1649 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo(); 1650 1651 if (enclosingInfo == null) 1652 return null; 1653 else { 1654 if (!enclosingInfo.isConstructor()) 1655 return null; 1656 1657 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(), 1658 getFactory()); 1659 Type [] parameterTypes = typeInfo.getParameterTypes(); 1660 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length]; 1661 1662 // Convert Types to Classes; returned types *should* 1663 // be class objects since the methodDescriptor's used 1664 // don't have generics information 1665 for (int i = 0; i < parameterClasses.length; i++) 1666 parameterClasses[i] = toClass(parameterTypes[i]); 1667 1668 1669 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass(); 1670 Constructor<?>[] candidates = enclosingCandidate 1671 .privateGetDeclaredConstructors(false); 1672 /* 1673 * Loop over all declared constructors; match number 1674 * of and type of parameters. 1675 */ 1676 ReflectionFactory fact = getReflectionFactory(); 1677 for (Constructor<?> c : candidates) { 1678 if (arrayContentsEq(parameterClasses, 1679 fact.getExecutableSharedParameterTypes(c))) { 1680 return fact.copyConstructor(c); 1681 } 1682 } 1683 1684 throw new InternalError("Enclosing constructor not found"); 1685 } 1686 } 1687 1688 1689 /** 1690 * If the class or interface represented by this {@code Class} object 1691 * is a member of another class, returns the {@code Class} object 1692 * representing the class in which it was declared. This method returns 1693 * null if this class or interface is not a member of any other class. If 1694 * this {@code Class} object represents an array class, a primitive 1695 * type, or void, then this method returns null. 1696 * 1697 * @return the declaring class for this class 1698 * @since 1.1 1699 */ 1700 public Class<?> getDeclaringClass() { 1701 return getDeclaringClass0(); 1702 } 1703 1704 private native Class<?> getDeclaringClass0(); 1705 1706 1707 /** 1708 * Returns the immediately enclosing class of the underlying 1709 * class. If the underlying class is a top level class this 1710 * method returns {@code null}. 1711 * @return the immediately enclosing class of the underlying class 1712 * @since 1.5 1713 */ 1714 public Class<?> getEnclosingClass() { 1715 // There are five kinds of classes (or interfaces): 1716 // a) Top level classes 1717 // b) Nested classes (static member classes) 1718 // c) Inner classes (non-static member classes) 1719 // d) Local classes (named classes declared within a method) 1720 // e) Anonymous classes 1721 1722 1723 // JVM Spec 4.7.7: A class must have an EnclosingMethod 1724 // attribute if and only if it is a local class or an 1725 // anonymous class. 1726 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo(); 1727 Class<?> enclosingCandidate; 1728 1729 if (enclosingInfo == null) { 1730 // This is a top level or a nested class or an inner class (a, b, or c) 1731 enclosingCandidate = getDeclaringClass0(); 1732 } else { 1733 Class<?> enclosingClass = enclosingInfo.getEnclosingClass(); 1734 // This is a local class or an anonymous class (d or e) 1735 if (enclosingClass == this || enclosingClass == null) 1736 throw new InternalError("Malformed enclosing method information"); 1737 else 1738 enclosingCandidate = enclosingClass; 1739 } 1740 return enclosingCandidate; 1741 } 1742 1743 /** 1744 * Returns the simple name of the underlying class as given in the 1745 * source code. An empty string is returned if the underlying class is 1746 * {@linkplain #isAnonymousClass() anonymous}. 1747 * A {@linkplain #isSynthetic() synthetic class}, one not present 1748 * in source code, can have a non-empty name including special 1749 * characters, such as "{@code $}". 1750 * 1751 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the 1752 * component type with "[]" appended. In particular the simple 1753 * name of an array class whose component type is anonymous is "[]". 1754 * 1755 * @return the simple name of the underlying class 1756 * @since 1.5 1757 */ 1758 public String getSimpleName() { 1759 ReflectionData<T> rd = reflectionData(); 1760 String simpleName = rd.simpleName; 1761 if (simpleName == null) { 1762 rd.simpleName = simpleName = getSimpleName0(); 1763 } 1764 return simpleName; 1765 } 1766 1767 private String getSimpleName0() { 1768 if (isArray()) { 1769 return getComponentType().getSimpleName().concat("[]"); 1770 } 1771 String simpleName = getSimpleBinaryName(); 1772 if (simpleName == null) { // top level class 1773 simpleName = getName(); 1774 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name 1775 } 1776 return simpleName; 1777 } 1778 1779 /** 1780 * Return an informative string for the name of this class or interface. 1781 * 1782 * @return an informative string for the name of this class or interface 1783 * @since 1.8 1784 */ 1785 public String getTypeName() { 1786 if (isArray()) { 1787 try { 1788 Class<?> cl = this; 1789 int dimensions = 0; 1790 do { 1791 dimensions++; 1792 cl = cl.getComponentType(); 1793 } while (cl.isArray()); 1794 return cl.getName().concat("[]".repeat(dimensions)); 1795 } catch (Throwable e) { /*FALLTHRU*/ } 1796 } 1797 return getName(); 1798 } 1799 1800 /** 1801 * Returns the canonical name of the underlying class as 1802 * defined by <cite>The Java Language Specification</cite>. 1803 * Returns {@code null} if the underlying class does not have a canonical 1804 * name. Classes without canonical names include: 1805 * <ul> 1806 * <li>a {@linkplain #isLocalClass() local class} 1807 * <li>a {@linkplain #isAnonymousClass() anonymous class} 1808 * <li>a {@linkplain #isHidden() hidden class} 1809 * <li>an array whose component type does not have a canonical name</li> 1810 * </ul> 1811 * 1812 * The canonical name for a primitive class is the keyword for the 1813 * corresponding primitive type ({@code byte}, {@code short}, 1814 * {@code char}, {@code int}, and so on). 1815 * 1816 * <p>An array type has a canonical name if and only if its 1817 * component type has a canonical name. When an array type has a 1818 * canonical name, it is equal to the canonical name of the 1819 * component type followed by "{@code []}". 1820 * 1821 * @return the canonical name of the underlying class if it exists, and 1822 * {@code null} otherwise. 1823 * @jls 6.7 Fully Qualified Names and Canonical Names 1824 * @since 1.5 1825 */ 1826 public String getCanonicalName() { 1827 ReflectionData<T> rd = reflectionData(); 1828 String canonicalName = rd.canonicalName; 1829 if (canonicalName == null) { 1830 rd.canonicalName = canonicalName = getCanonicalName0(); 1831 } 1832 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName; 1833 } 1834 1835 private String getCanonicalName0() { 1836 if (isArray()) { 1837 String canonicalName = getComponentType().getCanonicalName(); 1838 if (canonicalName != null) 1839 return canonicalName.concat("[]"); 1840 else 1841 return ReflectionData.NULL_SENTINEL; 1842 } 1843 if (isHidden() || isLocalOrAnonymousClass()) 1844 return ReflectionData.NULL_SENTINEL; 1845 Class<?> enclosingClass = getEnclosingClass(); 1846 if (enclosingClass == null) { // top level class 1847 return getName(); 1848 } else { 1849 String enclosingName = enclosingClass.getCanonicalName(); 1850 if (enclosingName == null) 1851 return ReflectionData.NULL_SENTINEL; 1852 String simpleName = getSimpleName(); 1853 return new StringBuilder(enclosingName.length() + simpleName.length() + 1) 1854 .append(enclosingName) 1855 .append('.') 1856 .append(simpleName) 1857 .toString(); 1858 } 1859 } 1860 1861 /** 1862 * Returns {@code true} if and only if the underlying class 1863 * is an anonymous class. 1864 * 1865 * @apiNote 1866 * An anonymous class is not a {@linkplain #isHidden() hidden class}. 1867 * 1868 * @return {@code true} if and only if this class is an anonymous class. 1869 * @since 1.5 1870 * @jls 15.9.5 Anonymous Class Declarations 1871 */ 1872 public boolean isAnonymousClass() { 1873 return !isArray() && isLocalOrAnonymousClass() && 1874 getSimpleBinaryName0() == null; 1875 } 1876 1877 /** 1878 * Returns {@code true} if and only if the underlying class 1879 * is a local class. 1880 * 1881 * @return {@code true} if and only if this class is a local class. 1882 * @since 1.5 1883 * @jls 14.3 Local Class and Interface Declarations 1884 */ 1885 public boolean isLocalClass() { 1886 return isLocalOrAnonymousClass() && 1887 (isArray() || getSimpleBinaryName0() != null); 1888 } 1889 1890 /** 1891 * Returns {@code true} if and only if the underlying class 1892 * is a member class. 1893 * 1894 * @return {@code true} if and only if this class is a member class. 1895 * @since 1.5 1896 * @jls 8.5 Member Class and Interface Declarations 1897 */ 1898 public boolean isMemberClass() { 1899 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null; 1900 } 1901 1902 /** 1903 * Returns the "simple binary name" of the underlying class, i.e., 1904 * the binary name without the leading enclosing class name. 1905 * Returns {@code null} if the underlying class is a top level 1906 * class. 1907 */ 1908 private String getSimpleBinaryName() { 1909 if (isTopLevelClass()) 1910 return null; 1911 String name = getSimpleBinaryName0(); 1912 if (name == null) // anonymous class 1913 return ""; 1914 return name; 1915 } 1916 1917 private native String getSimpleBinaryName0(); 1918 1919 /** 1920 * Returns {@code true} if this is a top level class. Returns {@code false} 1921 * otherwise. 1922 */ 1923 private boolean isTopLevelClass() { 1924 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null; 1925 } 1926 1927 /** 1928 * Returns {@code true} if this is a local class or an anonymous 1929 * class. Returns {@code false} otherwise. 1930 */ 1931 private boolean isLocalOrAnonymousClass() { 1932 // JVM Spec 4.7.7: A class must have an EnclosingMethod 1933 // attribute if and only if it is a local class or an 1934 // anonymous class. 1935 return hasEnclosingMethodInfo(); 1936 } 1937 1938 private boolean hasEnclosingMethodInfo() { 1939 Object[] enclosingInfo = getEnclosingMethod0(); 1940 if (enclosingInfo != null) { 1941 EnclosingMethodInfo.validate(enclosingInfo); 1942 return true; 1943 } 1944 return false; 1945 } 1946 1947 /** 1948 * Returns an array containing {@code Class} objects representing all 1949 * the public classes and interfaces that are members of the class 1950 * represented by this {@code Class} object. This includes public 1951 * class and interface members inherited from superclasses and public class 1952 * and interface members declared by the class. This method returns an 1953 * array of length 0 if this {@code Class} object has no public member 1954 * classes or interfaces. This method also returns an array of length 0 if 1955 * this {@code Class} object represents a primitive type, an array 1956 * class, or void. 1957 * 1958 * @return the array of {@code Class} objects representing the public 1959 * members of this class 1960 * @since 1.1 1961 */ 1962 public Class<?>[] getClasses() { 1963 List<Class<?>> list = new ArrayList<>(); 1964 Class<?> currentClass = Class.this; 1965 while (currentClass != null) { 1966 for (Class<?> m : currentClass.getDeclaredClasses()) { 1967 if (Modifier.isPublic(m.getModifiers())) { 1968 list.add(m); 1969 } 1970 } 1971 currentClass = currentClass.getSuperclass(); 1972 } 1973 return list.toArray(new Class<?>[0]); 1974 } 1975 1976 1977 /** 1978 * Returns an array containing {@code Field} objects reflecting all 1979 * the accessible public fields of the class or interface represented by 1980 * this {@code Class} object. 1981 * 1982 * <p> If this {@code Class} object represents a class or interface with 1983 * no accessible public fields, then this method returns an array of length 1984 * 0. 1985 * 1986 * <p> If this {@code Class} object represents a class, then this method 1987 * returns the public fields of the class and of all its superclasses and 1988 * superinterfaces. 1989 * 1990 * <p> If this {@code Class} object represents an interface, then this 1991 * method returns the fields of the interface and of all its 1992 * superinterfaces. 1993 * 1994 * <p> If this {@code Class} object represents an array type, a primitive 1995 * type, or void, then this method returns an array of length 0. 1996 * 1997 * <p> The elements in the returned array are not sorted and are not in any 1998 * particular order. 1999 * 2000 * @return the array of {@code Field} objects representing the 2001 * public fields 2002 * 2003 * @since 1.1 2004 * @jls 8.2 Class Members 2005 * @jls 8.3 Field Declarations 2006 */ 2007 public Field[] getFields() { 2008 return copyFields(privateGetPublicFields()); 2009 } 2010 2011 2012 /** 2013 * Returns an array containing {@code Method} objects reflecting all the 2014 * public methods of the class or interface represented by this {@code 2015 * Class} object, including those declared by the class or interface and 2016 * those inherited from superclasses and superinterfaces. 2017 * 2018 * <p> If this {@code Class} object represents an array type, then the 2019 * returned array has a {@code Method} object for each of the public 2020 * methods inherited by the array type from {@code Object}. It does not 2021 * contain a {@code Method} object for {@code clone()}. 2022 * 2023 * <p> If this {@code Class} object represents an interface then the 2024 * returned array does not contain any implicitly declared methods from 2025 * {@code Object}. Therefore, if no methods are explicitly declared in 2026 * this interface or any of its superinterfaces then the returned array 2027 * has length 0. (Note that a {@code Class} object which represents a class 2028 * always has public methods, inherited from {@code Object}.) 2029 * 2030 * <p> The returned array never contains methods with names {@value 2031 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}. 2032 * 2033 * <p> The elements in the returned array are not sorted and are not in any 2034 * particular order. 2035 * 2036 * <p> Generally, the result is computed as with the following 4 step algorithm. 2037 * Let C be the class or interface represented by this {@code Class} object: 2038 * <ol> 2039 * <li> A union of methods is composed of: 2040 * <ol type="a"> 2041 * <li> C's declared public instance and static methods as returned by 2042 * {@link #getDeclaredMethods()} and filtered to include only public 2043 * methods.</li> 2044 * <li> If C is a class other than {@code Object}, then include the result 2045 * of invoking this algorithm recursively on the superclass of C.</li> 2046 * <li> Include the results of invoking this algorithm recursively on all 2047 * direct superinterfaces of C, but include only instance methods.</li> 2048 * </ol></li> 2049 * <li> Union from step 1 is partitioned into subsets of methods with same 2050 * signature (name, parameter types) and return type.</li> 2051 * <li> Within each such subset only the most specific methods are selected. 2052 * Let method M be a method from a set of methods with same signature 2053 * and return type. M is most specific if there is no such method 2054 * N != M from the same set, such that N is more specific than M. 2055 * N is more specific than M if: 2056 * <ol type="a"> 2057 * <li> N is declared by a class and M is declared by an interface; or</li> 2058 * <li> N and M are both declared by classes or both by interfaces and 2059 * N's declaring type is the same as or a subtype of M's declaring type 2060 * (clearly, if M's and N's declaring types are the same type, then 2061 * M and N are the same method).</li> 2062 * </ol></li> 2063 * <li> The result of this algorithm is the union of all selected methods from 2064 * step 3.</li> 2065 * </ol> 2066 * 2067 * @apiNote There may be more than one method with a particular name 2068 * and parameter types in a class because while the Java language forbids a 2069 * class to declare multiple methods with the same signature but different 2070 * return types, the Java virtual machine does not. This 2071 * increased flexibility in the virtual machine can be used to 2072 * implement various language features. For example, covariant 2073 * returns can be implemented with {@linkplain 2074 * java.lang.reflect.Method#isBridge bridge methods}; the bridge 2075 * method and the overriding method would have the same 2076 * signature but different return types. 2077 * 2078 * @return the array of {@code Method} objects representing the 2079 * public methods of this class 2080 * 2081 * @jls 8.2 Class Members 2082 * @jls 8.4 Method Declarations 2083 * @since 1.1 2084 */ 2085 public Method[] getMethods() { 2086 return copyMethods(privateGetPublicMethods()); 2087 } 2088 2089 2090 /** 2091 * Returns an array containing {@code Constructor} objects reflecting 2092 * all the public constructors of the class represented by this 2093 * {@code Class} object. An array of length 0 is returned if the 2094 * class has no public constructors, or if the class is an array class, or 2095 * if the class reflects a primitive type or void. 2096 * 2097 * @apiNote 2098 * While this method returns an array of {@code 2099 * Constructor<T>} objects (that is an array of constructors from 2100 * this class), the return type of this method is {@code 2101 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as 2102 * might be expected. This less informative return type is 2103 * necessary since after being returned from this method, the 2104 * array could be modified to hold {@code Constructor} objects for 2105 * different classes, which would violate the type guarantees of 2106 * {@code Constructor<T>[]}. 2107 * 2108 * @return the array of {@code Constructor} objects representing the 2109 * public constructors of this class 2110 * 2111 * @see #getDeclaredConstructors() 2112 * @since 1.1 2113 */ 2114 public Constructor<?>[] getConstructors() { 2115 return copyConstructors(privateGetDeclaredConstructors(true)); 2116 } 2117 2118 2119 /** 2120 * Returns a {@code Field} object that reflects the specified public member 2121 * field of the class or interface represented by this {@code Class} 2122 * object. The {@code name} parameter is a {@code String} specifying the 2123 * simple name of the desired field. 2124 * 2125 * <p> The field to be reflected is determined by the algorithm that 2126 * follows. Let C be the class or interface represented by this {@code Class} object: 2127 * 2128 * <OL> 2129 * <LI> If C declares a public field with the name specified, that is the 2130 * field to be reflected.</LI> 2131 * <LI> If no field was found in step 1 above, this algorithm is applied 2132 * recursively to each direct superinterface of C. The direct 2133 * superinterfaces are searched in the order they were declared.</LI> 2134 * <LI> If no field was found in steps 1 and 2 above, and C has a 2135 * superclass S, then this algorithm is invoked recursively upon S. 2136 * If C has no superclass, then a {@code NoSuchFieldException} 2137 * is thrown.</LI> 2138 * </OL> 2139 * 2140 * <p> If this {@code Class} object represents an array type, then this 2141 * method does not find the {@code length} field of the array type. 2142 * 2143 * @param name the field name 2144 * @return the {@code Field} object of this class specified by 2145 * {@code name} 2146 * @throws NoSuchFieldException if a field with the specified name is 2147 * not found. 2148 * @throws NullPointerException if {@code name} is {@code null} 2149 * 2150 * @since 1.1 2151 * @jls 8.2 Class Members 2152 * @jls 8.3 Field Declarations 2153 */ 2154 public Field getField(String name) throws NoSuchFieldException { 2155 Objects.requireNonNull(name); 2156 Field field = getField0(name); 2157 if (field == null) { 2158 throw new NoSuchFieldException(name); 2159 } 2160 return getReflectionFactory().copyField(field); 2161 } 2162 2163 2164 /** 2165 * Returns a {@code Method} object that reflects the specified public 2166 * member method of the class or interface represented by this 2167 * {@code Class} object. The {@code name} parameter is a 2168 * {@code String} specifying the simple name of the desired method. The 2169 * {@code parameterTypes} parameter is an array of {@code Class} 2170 * objects that identify the method's formal parameter types, in declared 2171 * order. If {@code parameterTypes} is {@code null}, it is 2172 * treated as if it were an empty array. 2173 * 2174 * <p> If this {@code Class} object represents an array type, then this 2175 * method finds any public method inherited by the array type from 2176 * {@code Object} except method {@code clone()}. 2177 * 2178 * <p> If this {@code Class} object represents an interface then this 2179 * method does not find any implicitly declared method from 2180 * {@code Object}. Therefore, if no methods are explicitly declared in 2181 * this interface or any of its superinterfaces, then this method does not 2182 * find any method. 2183 * 2184 * <p> This method does not find any method with name {@value 2185 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}. 2186 * 2187 * <p> Generally, the method to be reflected is determined by the 4 step 2188 * algorithm that follows. 2189 * Let C be the class or interface represented by this {@code Class} object: 2190 * <ol> 2191 * <li> A union of methods is composed of: 2192 * <ol type="a"> 2193 * <li> C's declared public instance and static methods as returned by 2194 * {@link #getDeclaredMethods()} and filtered to include only public 2195 * methods that match given {@code name} and {@code parameterTypes}</li> 2196 * <li> If C is a class other than {@code Object}, then include the result 2197 * of invoking this algorithm recursively on the superclass of C.</li> 2198 * <li> Include the results of invoking this algorithm recursively on all 2199 * direct superinterfaces of C, but include only instance methods.</li> 2200 * </ol></li> 2201 * <li> This union is partitioned into subsets of methods with same 2202 * return type (the selection of methods from step 1 also guarantees that 2203 * they have the same method name and parameter types).</li> 2204 * <li> Within each such subset only the most specific methods are selected. 2205 * Let method M be a method from a set of methods with same VM 2206 * signature (return type, name, parameter types). 2207 * M is most specific if there is no such method N != M from the same 2208 * set, such that N is more specific than M. N is more specific than M 2209 * if: 2210 * <ol type="a"> 2211 * <li> N is declared by a class and M is declared by an interface; or</li> 2212 * <li> N and M are both declared by classes or both by interfaces and 2213 * N's declaring type is the same as or a subtype of M's declaring type 2214 * (clearly, if M's and N's declaring types are the same type, then 2215 * M and N are the same method).</li> 2216 * </ol></li> 2217 * <li> The result of this algorithm is chosen arbitrarily from the methods 2218 * with most specific return type among all selected methods from step 3. 2219 * Let R be a return type of a method M from the set of all selected methods 2220 * from step 3. M is a method with most specific return type if there is 2221 * no such method N != M from the same set, having return type S != R, 2222 * such that S is a subtype of R as determined by 2223 * R.class.{@link #isAssignableFrom}(S.class). 2224 * </ol> 2225 * 2226 * @apiNote There may be more than one method with matching name and 2227 * parameter types in a class because while the Java language forbids a 2228 * class to declare multiple methods with the same signature but different 2229 * return types, the Java virtual machine does not. This 2230 * increased flexibility in the virtual machine can be used to 2231 * implement various language features. For example, covariant 2232 * returns can be implemented with {@linkplain 2233 * java.lang.reflect.Method#isBridge bridge methods}; the bridge 2234 * method and the overriding method would have the same 2235 * signature but different return types. This method would return the 2236 * overriding method as it would have a more specific return type. 2237 * 2238 * @param name the name of the method 2239 * @param parameterTypes the list of parameters 2240 * @return the {@code Method} object that matches the specified 2241 * {@code name} and {@code parameterTypes} 2242 * @throws NoSuchMethodException if a matching method is not found 2243 * or if the name is {@value ConstantDescs#INIT_NAME} or 2244 * {@value ConstantDescs#CLASS_INIT_NAME}. 2245 * @throws NullPointerException if {@code name} is {@code null} 2246 * 2247 * @jls 8.2 Class Members 2248 * @jls 8.4 Method Declarations 2249 * @since 1.1 2250 */ 2251 public Method getMethod(String name, Class<?>... parameterTypes) 2252 throws NoSuchMethodException { 2253 Objects.requireNonNull(name); 2254 Method method = getMethod0(name, parameterTypes); 2255 if (method == null) { 2256 throw new NoSuchMethodException(methodToString(name, parameterTypes)); 2257 } 2258 return getReflectionFactory().copyMethod(method); 2259 } 2260 2261 /** 2262 * Returns a {@code Constructor} object that reflects the specified 2263 * public constructor of the class represented by this {@code Class} 2264 * object. The {@code parameterTypes} parameter is an array of 2265 * {@code Class} objects that identify the constructor's formal 2266 * parameter types, in declared order. 2267 * 2268 * If this {@code Class} object represents an inner class 2269 * declared in a non-static context, the formal parameter types 2270 * include the explicit enclosing instance as the first parameter. 2271 * 2272 * <p> The constructor to reflect is the public constructor of the class 2273 * represented by this {@code Class} object whose formal parameter 2274 * types match those specified by {@code parameterTypes}. 2275 * 2276 * @param parameterTypes the parameter array 2277 * @return the {@code Constructor} object of the public constructor that 2278 * matches the specified {@code parameterTypes} 2279 * @throws NoSuchMethodException if a matching constructor is not found, 2280 * including when this {@code Class} object represents 2281 * an interface, a primitive type, an array class, or void. 2282 * 2283 * @see #getDeclaredConstructor(Class[]) 2284 * @since 1.1 2285 */ 2286 public Constructor<T> getConstructor(Class<?>... parameterTypes) 2287 throws NoSuchMethodException { 2288 return getReflectionFactory().copyConstructor( 2289 getConstructor0(parameterTypes, Member.PUBLIC)); 2290 } 2291 2292 2293 /** 2294 * Returns an array of {@code Class} objects reflecting all the 2295 * classes and interfaces declared as members of the class represented by 2296 * this {@code Class} object. This includes public, protected, default 2297 * (package) access, and private classes and interfaces declared by the 2298 * class, but excludes inherited classes and interfaces. This method 2299 * returns an array of length 0 if the class declares no classes or 2300 * interfaces as members, or if this {@code Class} object represents a 2301 * primitive type, an array class, or void. 2302 * 2303 * @return the array of {@code Class} objects representing all the 2304 * declared members of this class 2305 * 2306 * @since 1.1 2307 * @jls 8.5 Member Class and Interface Declarations 2308 */ 2309 public Class<?>[] getDeclaredClasses() { 2310 return getDeclaredClasses0(); 2311 } 2312 2313 2314 /** 2315 * Returns an array of {@code Field} objects reflecting all the fields 2316 * declared by the class or interface represented by this 2317 * {@code Class} object. This includes public, protected, default 2318 * (package) access, and private fields, but excludes inherited fields. 2319 * 2320 * <p> If this {@code Class} object represents a class or interface with no 2321 * declared fields, then this method returns an array of length 0. 2322 * 2323 * <p> If this {@code Class} object represents an array type, a primitive 2324 * type, or void, then this method returns an array of length 0. 2325 * 2326 * <p> The elements in the returned array are not sorted and are not in any 2327 * particular order. 2328 * 2329 * @return the array of {@code Field} objects representing all the 2330 * declared fields of this class 2331 * 2332 * @since 1.1 2333 * @jls 8.2 Class Members 2334 * @jls 8.3 Field Declarations 2335 */ 2336 public Field[] getDeclaredFields() { 2337 return copyFields(privateGetDeclaredFields(false)); 2338 } 2339 2340 /** 2341 * Returns an array of {@code RecordComponent} objects representing all the 2342 * record components of this record class, or {@code null} if this class is 2343 * not a record class. 2344 * 2345 * <p> The components are returned in the same order that they are declared 2346 * in the record header. The array is empty if this record class has no 2347 * components. If the class is not a record class, that is {@link 2348 * #isRecord()} returns {@code false}, then this method returns {@code null}. 2349 * Conversely, if {@link #isRecord()} returns {@code true}, then this method 2350 * returns a non-null value. 2351 * 2352 * @apiNote 2353 * <p> The following method can be used to find the record canonical constructor: 2354 * 2355 * {@snippet lang="java" : 2356 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls) 2357 * throws NoSuchMethodException { 2358 * Class<?>[] paramTypes = 2359 * Arrays.stream(cls.getRecordComponents()) 2360 * .map(RecordComponent::getType) 2361 * .toArray(Class<?>[]::new); 2362 * return cls.getDeclaredConstructor(paramTypes); 2363 * }} 2364 * 2365 * @return An array of {@code RecordComponent} objects representing all the 2366 * record components of this record class, or {@code null} if this 2367 * class is not a record class 2368 * 2369 * @jls 8.10 Record Classes 2370 * @since 16 2371 */ 2372 public RecordComponent[] getRecordComponents() { 2373 if (!isRecord()) { 2374 return null; 2375 } 2376 return getRecordComponents0(); 2377 } 2378 2379 /** 2380 * Returns an array containing {@code Method} objects reflecting all the 2381 * declared methods of the class or interface represented by this {@code 2382 * Class} object, including public, protected, default (package) 2383 * access, and private methods, but excluding inherited methods. 2384 * The declared methods may include methods <em>not</em> in the 2385 * source of the class or interface, including {@linkplain 2386 * Method#isBridge bridge methods} and other {@linkplain 2387 * Executable#isSynthetic synthetic} methods added by compilers. 2388 * 2389 * <p> If this {@code Class} object represents a class or interface that 2390 * has multiple declared methods with the same name and parameter types, 2391 * but different return types, then the returned array has a {@code Method} 2392 * object for each such method. 2393 * 2394 * <p> If this {@code Class} object represents a class or interface that 2395 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME}, 2396 * then the returned array does <em>not</em> have a corresponding {@code 2397 * Method} object. 2398 * 2399 * <p> If this {@code Class} object represents a class or interface with no 2400 * declared methods, then the returned array has length 0. 2401 * 2402 * <p> If this {@code Class} object represents an array type, a primitive 2403 * type, or void, then the returned array has length 0. 2404 * 2405 * <p> The elements in the returned array are not sorted and are not in any 2406 * particular order. 2407 * 2408 * @return the array of {@code Method} objects representing all the 2409 * declared methods of this class 2410 * 2411 * @jls 8.2 Class Members 2412 * @jls 8.4 Method Declarations 2413 * @see <a 2414 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java 2415 * programming language and JVM modeling in core reflection</a> 2416 * @since 1.1 2417 */ 2418 public Method[] getDeclaredMethods() { 2419 return copyMethods(privateGetDeclaredMethods(false)); 2420 } 2421 2422 /** 2423 * Returns an array of {@code Constructor} objects reflecting all the 2424 * constructors implicitly or explicitly declared by the class represented by this 2425 * {@code Class} object. These are public, protected, default 2426 * (package) access, and private constructors. The elements in the array 2427 * returned are not sorted and are not in any particular order. If the 2428 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array. 2429 * If a record class has a canonical constructor (JLS {@jls 2430 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array. 2431 * 2432 * This method returns an array of length 0 if this {@code Class} 2433 * object represents an interface, a primitive type, an array class, or 2434 * void. 2435 * 2436 * @return the array of {@code Constructor} objects representing all the 2437 * declared constructors of this class 2438 * 2439 * @since 1.1 2440 * @see #getConstructors() 2441 * @jls 8.8 Constructor Declarations 2442 */ 2443 public Constructor<?>[] getDeclaredConstructors() { 2444 return copyConstructors(privateGetDeclaredConstructors(false)); 2445 } 2446 2447 2448 /** 2449 * Returns a {@code Field} object that reflects the specified declared 2450 * field of the class or interface represented by this {@code Class} 2451 * object. The {@code name} parameter is a {@code String} that specifies 2452 * the simple name of the desired field. 2453 * 2454 * <p> If this {@code Class} object represents an array type, then this 2455 * method does not find the {@code length} field of the array type. 2456 * 2457 * @param name the name of the field 2458 * @return the {@code Field} object for the specified field in this 2459 * class 2460 * @throws NoSuchFieldException if a field with the specified name is 2461 * not found. 2462 * @throws NullPointerException if {@code name} is {@code null} 2463 * 2464 * @since 1.1 2465 * @jls 8.2 Class Members 2466 * @jls 8.3 Field Declarations 2467 */ 2468 public Field getDeclaredField(String name) throws NoSuchFieldException { 2469 Objects.requireNonNull(name); 2470 Field field = searchFields(privateGetDeclaredFields(false), name); 2471 if (field == null) { 2472 throw new NoSuchFieldException(name); 2473 } 2474 return getReflectionFactory().copyField(field); 2475 } 2476 2477 2478 /** 2479 * Returns a {@code Method} object that reflects the specified 2480 * declared method of the class or interface represented by this 2481 * {@code Class} object. The {@code name} parameter is a 2482 * {@code String} that specifies the simple name of the desired 2483 * method, and the {@code parameterTypes} parameter is an array of 2484 * {@code Class} objects that identify the method's formal parameter 2485 * types, in declared order. If more than one method with the same 2486 * parameter types is declared in a class, and one of these methods has a 2487 * return type that is more specific than any of the others, that method is 2488 * returned; otherwise one of the methods is chosen arbitrarily. If the 2489 * name is {@value ConstantDescs#INIT_NAME} or {@value 2490 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException} 2491 * is raised. 2492 * 2493 * <p> If this {@code Class} object represents an array type, then this 2494 * method does not find the {@code clone()} method. 2495 * 2496 * @param name the name of the method 2497 * @param parameterTypes the parameter array 2498 * @return the {@code Method} object for the method of this class 2499 * matching the specified name and parameters 2500 * @throws NoSuchMethodException if a matching method is not found. 2501 * @throws NullPointerException if {@code name} is {@code null} 2502 * 2503 * @jls 8.2 Class Members 2504 * @jls 8.4 Method Declarations 2505 * @since 1.1 2506 */ 2507 public Method getDeclaredMethod(String name, Class<?>... parameterTypes) 2508 throws NoSuchMethodException { 2509 Objects.requireNonNull(name); 2510 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes); 2511 if (method == null) { 2512 throw new NoSuchMethodException(methodToString(name, parameterTypes)); 2513 } 2514 return getReflectionFactory().copyMethod(method); 2515 } 2516 2517 /** 2518 * Returns the list of {@code Method} objects for the declared public 2519 * methods of this class or interface that have the specified method name 2520 * and parameter types. 2521 * 2522 * @param name the name of the method 2523 * @param parameterTypes the parameter array 2524 * @return the list of {@code Method} objects for the public methods of 2525 * this class matching the specified name and parameters 2526 */ 2527 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) { 2528 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true); 2529 ReflectionFactory factory = getReflectionFactory(); 2530 List<Method> result = new ArrayList<>(); 2531 for (Method method : methods) { 2532 if (method.getName().equals(name) 2533 && Arrays.equals( 2534 factory.getExecutableSharedParameterTypes(method), 2535 parameterTypes)) { 2536 result.add(factory.copyMethod(method)); 2537 } 2538 } 2539 return result; 2540 } 2541 2542 /** 2543 * Returns the most specific {@code Method} object of this class, super class or 2544 * interface that have the specified method name and parameter types. 2545 * 2546 * @param publicOnly true if only public methods are examined, otherwise all methods 2547 * @param name the name of the method 2548 * @param parameterTypes the parameter array 2549 * @return the {@code Method} object for the method found from this class matching 2550 * the specified name and parameters, or null if not found 2551 */ 2552 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) { 2553 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly); 2554 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific()); 2555 } 2556 2557 /** 2558 * Returns a {@code Constructor} object that reflects the specified 2559 * constructor of the class represented by this 2560 * {@code Class} object. The {@code parameterTypes} parameter is 2561 * an array of {@code Class} objects that identify the constructor's 2562 * formal parameter types, in declared order. 2563 * 2564 * If this {@code Class} object represents an inner class 2565 * declared in a non-static context, the formal parameter types 2566 * include the explicit enclosing instance as the first parameter. 2567 * 2568 * @param parameterTypes the parameter array 2569 * @return The {@code Constructor} object for the constructor with the 2570 * specified parameter list 2571 * @throws NoSuchMethodException if a matching constructor is not found, 2572 * including when this {@code Class} object represents 2573 * an interface, a primitive type, an array class, or void. 2574 * 2575 * @see #getConstructor(Class[]) 2576 * @since 1.1 2577 */ 2578 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes) 2579 throws NoSuchMethodException { 2580 return getReflectionFactory().copyConstructor( 2581 getConstructor0(parameterTypes, Member.DECLARED)); 2582 } 2583 2584 /** 2585 * Finds a resource with a given name. 2586 * 2587 * <p> If this class is in a named {@link Module Module} then this method 2588 * will attempt to find the resource in the module. This is done by 2589 * delegating to the module's class loader {@link 2590 * ClassLoader#findResource(String,String) findResource(String,String)} 2591 * method, invoking it with the module name and the absolute name of the 2592 * resource. Resources in named modules are subject to the rules for 2593 * encapsulation specified in the {@code Module} {@link 2594 * Module#getResourceAsStream getResourceAsStream} method and so this 2595 * method returns {@code null} when the resource is a 2596 * non-"{@code .class}" resource in a package that is not open to the 2597 * caller's module. 2598 * 2599 * <p> Otherwise, if this class is not in a named module then the rules for 2600 * searching resources associated with a given class are implemented by the 2601 * defining {@linkplain ClassLoader class loader} of the class. This method 2602 * delegates to this {@code Class} object's class loader. 2603 * If this {@code Class} object was loaded by the bootstrap class loader, 2604 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}. 2605 * 2606 * <p> Before delegation, an absolute resource name is constructed from the 2607 * given resource name using this algorithm: 2608 * 2609 * <ul> 2610 * 2611 * <li> If the {@code name} begins with a {@code '/'} 2612 * (<code>'\u002f'</code>), then the absolute name of the resource is the 2613 * portion of the {@code name} following the {@code '/'}. 2614 * 2615 * <li> Otherwise, the absolute name is of the following form: 2616 * 2617 * <blockquote> 2618 * {@code modified_package_name/name} 2619 * </blockquote> 2620 * 2621 * <p> Where the {@code modified_package_name} is the package name of this 2622 * object with {@code '/'} substituted for {@code '.'} 2623 * (<code>'\u002e'</code>). 2624 * 2625 * </ul> 2626 * 2627 * @param name name of the desired resource 2628 * @return A {@link java.io.InputStream} object; {@code null} if no 2629 * resource with this name is found, or the resource is in a package 2630 * that is not {@linkplain Module#isOpen(String, Module) open} to at 2631 * least the caller module. 2632 * @throws NullPointerException If {@code name} is {@code null} 2633 * 2634 * @see Module#getResourceAsStream(String) 2635 * @since 1.1 2636 */ 2637 @CallerSensitive 2638 public InputStream getResourceAsStream(String name) { 2639 name = resolveName(name); 2640 2641 Module thisModule = getModule(); 2642 if (thisModule.isNamed()) { 2643 // check if resource can be located by caller 2644 if (Resources.canEncapsulate(name) 2645 && !isOpenToCaller(name, Reflection.getCallerClass())) { 2646 return null; 2647 } 2648 2649 // resource not encapsulated or in package open to caller 2650 String mn = thisModule.getName(); 2651 ClassLoader cl = classLoader; 2652 try { 2653 2654 // special-case built-in class loaders to avoid the 2655 // need for a URL connection 2656 if (cl == null) { 2657 return BootLoader.findResourceAsStream(mn, name); 2658 } else if (cl instanceof BuiltinClassLoader bcl) { 2659 return bcl.findResourceAsStream(mn, name); 2660 } else { 2661 URL url = cl.findResource(mn, name); 2662 return (url != null) ? url.openStream() : null; 2663 } 2664 2665 } catch (IOException | SecurityException e) { 2666 return null; 2667 } 2668 } 2669 2670 // unnamed module 2671 ClassLoader cl = classLoader; 2672 if (cl == null) { 2673 return ClassLoader.getSystemResourceAsStream(name); 2674 } else { 2675 return cl.getResourceAsStream(name); 2676 } 2677 } 2678 2679 /** 2680 * Finds a resource with a given name. 2681 * 2682 * <p> If this class is in a named {@link Module Module} then this method 2683 * will attempt to find the resource in the module. This is done by 2684 * delegating to the module's class loader {@link 2685 * ClassLoader#findResource(String,String) findResource(String,String)} 2686 * method, invoking it with the module name and the absolute name of the 2687 * resource. Resources in named modules are subject to the rules for 2688 * encapsulation specified in the {@code Module} {@link 2689 * Module#getResourceAsStream getResourceAsStream} method and so this 2690 * method returns {@code null} when the resource is a 2691 * non-"{@code .class}" resource in a package that is not open to the 2692 * caller's module. 2693 * 2694 * <p> Otherwise, if this class is not in a named module then the rules for 2695 * searching resources associated with a given class are implemented by the 2696 * defining {@linkplain ClassLoader class loader} of the class. This method 2697 * delegates to this {@code Class} object's class loader. 2698 * If this {@code Class} object was loaded by the bootstrap class loader, 2699 * the method delegates to {@link ClassLoader#getSystemResource}. 2700 * 2701 * <p> Before delegation, an absolute resource name is constructed from the 2702 * given resource name using this algorithm: 2703 * 2704 * <ul> 2705 * 2706 * <li> If the {@code name} begins with a {@code '/'} 2707 * (<code>'\u002f'</code>), then the absolute name of the resource is the 2708 * portion of the {@code name} following the {@code '/'}. 2709 * 2710 * <li> Otherwise, the absolute name is of the following form: 2711 * 2712 * <blockquote> 2713 * {@code modified_package_name/name} 2714 * </blockquote> 2715 * 2716 * <p> Where the {@code modified_package_name} is the package name of this 2717 * object with {@code '/'} substituted for {@code '.'} 2718 * (<code>'\u002e'</code>). 2719 * 2720 * </ul> 2721 * 2722 * @param name name of the desired resource 2723 * @return A {@link java.net.URL} object; {@code null} if no resource with 2724 * this name is found, the resource cannot be located by a URL, or the 2725 * resource is in a package that is not 2726 * {@linkplain Module#isOpen(String, Module) open} to at least the caller 2727 * module. 2728 * @throws NullPointerException If {@code name} is {@code null} 2729 * @since 1.1 2730 */ 2731 @CallerSensitive 2732 public URL getResource(String name) { 2733 name = resolveName(name); 2734 2735 Module thisModule = getModule(); 2736 if (thisModule.isNamed()) { 2737 // check if resource can be located by caller 2738 if (Resources.canEncapsulate(name) 2739 && !isOpenToCaller(name, Reflection.getCallerClass())) { 2740 return null; 2741 } 2742 2743 // resource not encapsulated or in package open to caller 2744 String mn = thisModule.getName(); 2745 ClassLoader cl = classLoader; 2746 try { 2747 if (cl == null) { 2748 return BootLoader.findResource(mn, name); 2749 } else { 2750 return cl.findResource(mn, name); 2751 } 2752 } catch (IOException ioe) { 2753 return null; 2754 } 2755 } 2756 2757 // unnamed module 2758 ClassLoader cl = classLoader; 2759 if (cl == null) { 2760 return ClassLoader.getSystemResource(name); 2761 } else { 2762 return cl.getResource(name); 2763 } 2764 } 2765 2766 /** 2767 * Returns true if a resource with the given name can be located by the 2768 * given caller. All resources in a module can be located by code in 2769 * the module. For other callers, then the package needs to be open to 2770 * the caller. 2771 */ 2772 private boolean isOpenToCaller(String name, Class<?> caller) { 2773 // assert getModule().isNamed(); 2774 Module thisModule = getModule(); 2775 Module callerModule = (caller != null) ? caller.getModule() : null; 2776 if (callerModule != thisModule) { 2777 String pn = Resources.toPackageName(name); 2778 if (thisModule.getDescriptor().packages().contains(pn)) { 2779 if (callerModule == null) { 2780 // no caller, return true if the package is open to all modules 2781 return thisModule.isOpen(pn); 2782 } 2783 if (!thisModule.isOpen(pn, callerModule)) { 2784 // package not open to caller 2785 return false; 2786 } 2787 } 2788 } 2789 return true; 2790 } 2791 2792 private transient final ProtectionDomain protectionDomain; 2793 2794 /** Holder for the protection domain returned when the internal domain is null */ 2795 private static class Holder { 2796 private static final ProtectionDomain allPermDomain; 2797 static { 2798 Permissions perms = new Permissions(); 2799 perms.add(new AllPermission()); 2800 allPermDomain = new ProtectionDomain(null, perms); 2801 } 2802 } 2803 2804 /** 2805 * Returns the {@code ProtectionDomain} of this class. 2806 * 2807 * @return the ProtectionDomain of this class 2808 * 2809 * @see java.security.ProtectionDomain 2810 * @since 1.2 2811 */ 2812 public ProtectionDomain getProtectionDomain() { 2813 if (protectionDomain == null) { 2814 return Holder.allPermDomain; 2815 } else { 2816 return protectionDomain; 2817 } 2818 } 2819 2820 /* 2821 * Returns the Class object for the named primitive type. Type parameter T 2822 * avoids redundant casts for trusted code. 2823 */ 2824 static native <T> Class<T> getPrimitiveClass(String name); 2825 2826 /** 2827 * Add a package name prefix if the name is not absolute. Remove leading "/" 2828 * if name is absolute 2829 */ 2830 private String resolveName(String name) { 2831 if (!name.startsWith("/")) { 2832 String baseName = getPackageName(); 2833 if (!baseName.isEmpty()) { 2834 int len = baseName.length() + 1 + name.length(); 2835 StringBuilder sb = new StringBuilder(len); 2836 name = sb.append(baseName.replace('.', '/')) 2837 .append('/') 2838 .append(name) 2839 .toString(); 2840 } 2841 } else { 2842 name = name.substring(1); 2843 } 2844 return name; 2845 } 2846 2847 /** 2848 * Atomic operations support. 2849 */ 2850 private static class Atomic { 2851 // initialize Unsafe machinery here, since we need to call Class.class instance method 2852 // and have to avoid calling it in the static initializer of the Class class... 2853 private static final Unsafe unsafe = Unsafe.getUnsafe(); 2854 // offset of Class.reflectionData instance field 2855 private static final long reflectionDataOffset 2856 = unsafe.objectFieldOffset(Class.class, "reflectionData"); 2857 // offset of Class.annotationType instance field 2858 private static final long annotationTypeOffset 2859 = unsafe.objectFieldOffset(Class.class, "annotationType"); 2860 // offset of Class.annotationData instance field 2861 private static final long annotationDataOffset 2862 = unsafe.objectFieldOffset(Class.class, "annotationData"); 2863 2864 static <T> boolean casReflectionData(Class<?> clazz, 2865 SoftReference<ReflectionData<T>> oldData, 2866 SoftReference<ReflectionData<T>> newData) { 2867 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData); 2868 } 2869 2870 static boolean casAnnotationType(Class<?> clazz, 2871 AnnotationType oldType, 2872 AnnotationType newType) { 2873 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType); 2874 } 2875 2876 static boolean casAnnotationData(Class<?> clazz, 2877 AnnotationData oldData, 2878 AnnotationData newData) { 2879 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData); 2880 } 2881 } 2882 2883 /** 2884 * Reflection support. 2885 */ 2886 2887 // Reflection data caches various derived names and reflective members. Cached 2888 // values may be invalidated when JVM TI RedefineClasses() is called 2889 private static class ReflectionData<T> { 2890 volatile Field[] declaredFields; 2891 volatile Field[] publicFields; 2892 volatile Method[] declaredMethods; 2893 volatile Method[] publicMethods; 2894 volatile Constructor<T>[] declaredConstructors; 2895 volatile Constructor<T>[] publicConstructors; 2896 // Intermediate results for getFields and getMethods 2897 volatile Field[] declaredPublicFields; 2898 volatile Method[] declaredPublicMethods; 2899 volatile Class<?>[] interfaces; 2900 2901 // Cached names 2902 String simpleName; 2903 String canonicalName; 2904 static final String NULL_SENTINEL = new String(); 2905 2906 // Value of classRedefinedCount when we created this ReflectionData instance 2907 final int redefinedCount; 2908 2909 ReflectionData(int redefinedCount) { 2910 this.redefinedCount = redefinedCount; 2911 } 2912 } 2913 2914 private transient volatile SoftReference<ReflectionData<T>> reflectionData; 2915 2916 // Incremented by the VM on each call to JVM TI RedefineClasses() 2917 // that redefines this class or a superclass. 2918 private transient volatile int classRedefinedCount; 2919 2920 // Lazily create and cache ReflectionData 2921 private ReflectionData<T> reflectionData() { 2922 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData; 2923 int classRedefinedCount = this.classRedefinedCount; 2924 ReflectionData<T> rd; 2925 if (reflectionData != null && 2926 (rd = reflectionData.get()) != null && 2927 rd.redefinedCount == classRedefinedCount) { 2928 return rd; 2929 } 2930 // else no SoftReference or cleared SoftReference or stale ReflectionData 2931 // -> create and replace new instance 2932 return newReflectionData(reflectionData, classRedefinedCount); 2933 } 2934 2935 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData, 2936 int classRedefinedCount) { 2937 while (true) { 2938 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount); 2939 // try to CAS it... 2940 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) { 2941 return rd; 2942 } 2943 // else retry 2944 oldReflectionData = this.reflectionData; 2945 classRedefinedCount = this.classRedefinedCount; 2946 if (oldReflectionData != null && 2947 (rd = oldReflectionData.get()) != null && 2948 rd.redefinedCount == classRedefinedCount) { 2949 return rd; 2950 } 2951 } 2952 } 2953 2954 // Generic signature handling 2955 private native String getGenericSignature0(); 2956 2957 // Generic info repository; lazily initialized 2958 private transient volatile ClassRepository genericInfo; 2959 2960 // accessor for factory 2961 private GenericsFactory getFactory() { 2962 // create scope and factory 2963 return CoreReflectionFactory.make(this, ClassScope.make(this)); 2964 } 2965 2966 // accessor for generic info repository; 2967 // generic info is lazily initialized 2968 private ClassRepository getGenericInfo() { 2969 ClassRepository genericInfo = this.genericInfo; 2970 if (genericInfo == null) { 2971 String signature = getGenericSignature0(); 2972 if (signature == null) { 2973 genericInfo = ClassRepository.NONE; 2974 } else { 2975 genericInfo = ClassRepository.make(signature, getFactory()); 2976 } 2977 this.genericInfo = genericInfo; 2978 } 2979 return (genericInfo != ClassRepository.NONE) ? genericInfo : null; 2980 } 2981 2982 // Annotations handling 2983 native byte[] getRawAnnotations(); 2984 // Since 1.8 2985 native byte[] getRawTypeAnnotations(); 2986 static byte[] getExecutableTypeAnnotationBytes(Executable ex) { 2987 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex); 2988 } 2989 2990 native ConstantPool getConstantPool(); 2991 2992 // 2993 // 2994 // java.lang.reflect.Field handling 2995 // 2996 // 2997 2998 // Returns an array of "root" fields. These Field objects must NOT 2999 // be propagated to the outside world, but must instead be copied 3000 // via ReflectionFactory.copyField. 3001 private Field[] privateGetDeclaredFields(boolean publicOnly) { 3002 Field[] res; 3003 ReflectionData<T> rd = reflectionData(); 3004 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields; 3005 if (res != null) return res; 3006 // No cached value available; request value from VM 3007 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly)); 3008 if (publicOnly) { 3009 rd.declaredPublicFields = res; 3010 } else { 3011 rd.declaredFields = res; 3012 } 3013 return res; 3014 } 3015 3016 // Returns an array of "root" fields. These Field objects must NOT 3017 // be propagated to the outside world, but must instead be copied 3018 // via ReflectionFactory.copyField. 3019 private Field[] privateGetPublicFields() { 3020 Field[] res; 3021 ReflectionData<T> rd = reflectionData(); 3022 res = rd.publicFields; 3023 if (res != null) return res; 3024 3025 // Use a linked hash set to ensure order is preserved and 3026 // fields from common super interfaces are not duplicated 3027 LinkedHashSet<Field> fields = new LinkedHashSet<>(); 3028 3029 // Local fields 3030 addAll(fields, privateGetDeclaredFields(true)); 3031 3032 // Direct superinterfaces, recursively 3033 for (Class<?> si : getInterfaces(/* cloneArray */ false)) { 3034 addAll(fields, si.privateGetPublicFields()); 3035 } 3036 3037 // Direct superclass, recursively 3038 Class<?> sc = getSuperclass(); 3039 if (sc != null) { 3040 addAll(fields, sc.privateGetPublicFields()); 3041 } 3042 3043 res = fields.toArray(new Field[0]); 3044 rd.publicFields = res; 3045 return res; 3046 } 3047 3048 private static void addAll(Collection<Field> c, Field[] o) { 3049 for (Field f : o) { 3050 c.add(f); 3051 } 3052 } 3053 3054 3055 // 3056 // 3057 // java.lang.reflect.Constructor handling 3058 // 3059 // 3060 3061 // Returns an array of "root" constructors. These Constructor 3062 // objects must NOT be propagated to the outside world, but must 3063 // instead be copied via ReflectionFactory.copyConstructor. 3064 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) { 3065 Constructor<T>[] res; 3066 ReflectionData<T> rd = reflectionData(); 3067 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors; 3068 if (res != null) return res; 3069 // No cached value available; request value from VM 3070 if (isInterface()) { 3071 @SuppressWarnings("unchecked") 3072 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0]; 3073 res = temporaryRes; 3074 } else { 3075 res = getDeclaredConstructors0(publicOnly); 3076 } 3077 if (publicOnly) { 3078 rd.publicConstructors = res; 3079 } else { 3080 rd.declaredConstructors = res; 3081 } 3082 return res; 3083 } 3084 3085 // 3086 // 3087 // java.lang.reflect.Method handling 3088 // 3089 // 3090 3091 // Returns an array of "root" methods. These Method objects must NOT 3092 // be propagated to the outside world, but must instead be copied 3093 // via ReflectionFactory.copyMethod. 3094 private Method[] privateGetDeclaredMethods(boolean publicOnly) { 3095 Method[] res; 3096 ReflectionData<T> rd = reflectionData(); 3097 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods; 3098 if (res != null) return res; 3099 // No cached value available; request value from VM 3100 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly)); 3101 if (publicOnly) { 3102 rd.declaredPublicMethods = res; 3103 } else { 3104 rd.declaredMethods = res; 3105 } 3106 return res; 3107 } 3108 3109 // Returns an array of "root" methods. These Method objects must NOT 3110 // be propagated to the outside world, but must instead be copied 3111 // via ReflectionFactory.copyMethod. 3112 private Method[] privateGetPublicMethods() { 3113 Method[] res; 3114 ReflectionData<T> rd = reflectionData(); 3115 res = rd.publicMethods; 3116 if (res != null) return res; 3117 3118 // No cached value available; compute value recursively. 3119 // Start by fetching public declared methods... 3120 PublicMethods pms = new PublicMethods(); 3121 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) { 3122 pms.merge(m); 3123 } 3124 // ...then recur over superclass methods... 3125 Class<?> sc = getSuperclass(); 3126 if (sc != null) { 3127 for (Method m : sc.privateGetPublicMethods()) { 3128 pms.merge(m); 3129 } 3130 } 3131 // ...and finally over direct superinterfaces. 3132 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) { 3133 for (Method m : intf.privateGetPublicMethods()) { 3134 // static interface methods are not inherited 3135 if (!Modifier.isStatic(m.getModifiers())) { 3136 pms.merge(m); 3137 } 3138 } 3139 } 3140 3141 res = pms.toArray(); 3142 rd.publicMethods = res; 3143 return res; 3144 } 3145 3146 3147 // 3148 // Helpers for fetchers of one field, method, or constructor 3149 // 3150 3151 // This method does not copy the returned Field object! 3152 private static Field searchFields(Field[] fields, String name) { 3153 for (Field field : fields) { 3154 if (field.getName().equals(name)) { 3155 return field; 3156 } 3157 } 3158 return null; 3159 } 3160 3161 // Returns a "root" Field object. This Field object must NOT 3162 // be propagated to the outside world, but must instead be copied 3163 // via ReflectionFactory.copyField. 3164 private Field getField0(String name) { 3165 // Note: the intent is that the search algorithm this routine 3166 // uses be equivalent to the ordering imposed by 3167 // privateGetPublicFields(). It fetches only the declared 3168 // public fields for each class, however, to reduce the number 3169 // of Field objects which have to be created for the common 3170 // case where the field being requested is declared in the 3171 // class which is being queried. 3172 Field res; 3173 // Search declared public fields 3174 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) { 3175 return res; 3176 } 3177 // Direct superinterfaces, recursively 3178 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false); 3179 for (Class<?> c : interfaces) { 3180 if ((res = c.getField0(name)) != null) { 3181 return res; 3182 } 3183 } 3184 // Direct superclass, recursively 3185 if (!isInterface()) { 3186 Class<?> c = getSuperclass(); 3187 if (c != null) { 3188 if ((res = c.getField0(name)) != null) { 3189 return res; 3190 } 3191 } 3192 } 3193 return null; 3194 } 3195 3196 // This method does not copy the returned Method object! 3197 private static Method searchMethods(Method[] methods, 3198 String name, 3199 Class<?>[] parameterTypes) 3200 { 3201 ReflectionFactory fact = getReflectionFactory(); 3202 Method res = null; 3203 for (Method m : methods) { 3204 if (m.getName().equals(name) 3205 && arrayContentsEq(parameterTypes, 3206 fact.getExecutableSharedParameterTypes(m)) 3207 && (res == null 3208 || (res.getReturnType() != m.getReturnType() 3209 && res.getReturnType().isAssignableFrom(m.getReturnType())))) 3210 res = m; 3211 } 3212 return res; 3213 } 3214 3215 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0]; 3216 3217 // Returns a "root" Method object. This Method object must NOT 3218 // be propagated to the outside world, but must instead be copied 3219 // via ReflectionFactory.copyMethod. 3220 private Method getMethod0(String name, Class<?>[] parameterTypes) { 3221 PublicMethods.MethodList res = getMethodsRecursive( 3222 name, 3223 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes, 3224 /* includeStatic */ true, /* publicOnly */ true); 3225 return res == null ? null : res.getMostSpecific(); 3226 } 3227 3228 // Returns a list of "root" Method objects. These Method objects must NOT 3229 // be propagated to the outside world, but must instead be copied 3230 // via ReflectionFactory.copyMethod. 3231 private PublicMethods.MethodList getMethodsRecursive(String name, 3232 Class<?>[] parameterTypes, 3233 boolean includeStatic, 3234 boolean publicOnly) { 3235 // 1st check declared methods 3236 Method[] methods = privateGetDeclaredMethods(publicOnly); 3237 PublicMethods.MethodList res = PublicMethods.MethodList 3238 .filter(methods, name, parameterTypes, includeStatic); 3239 // if there is at least one match among declared methods, we need not 3240 // search any further as such match surely overrides matching methods 3241 // declared in superclass(es) or interface(s). 3242 if (res != null) { 3243 return res; 3244 } 3245 3246 // if there was no match among declared methods, 3247 // we must consult the superclass (if any) recursively... 3248 Class<?> sc = getSuperclass(); 3249 if (sc != null) { 3250 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly); 3251 } 3252 3253 // ...and coalesce the superclass methods with methods obtained 3254 // from directly implemented interfaces excluding static methods... 3255 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) { 3256 res = PublicMethods.MethodList.merge( 3257 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly)); 3258 } 3259 3260 return res; 3261 } 3262 3263 // Returns a "root" Constructor object. This Constructor object must NOT 3264 // be propagated to the outside world, but must instead be copied 3265 // via ReflectionFactory.copyConstructor. 3266 private Constructor<T> getConstructor0(Class<?>[] parameterTypes, 3267 int which) throws NoSuchMethodException 3268 { 3269 ReflectionFactory fact = getReflectionFactory(); 3270 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC)); 3271 for (Constructor<T> constructor : constructors) { 3272 if (arrayContentsEq(parameterTypes, 3273 fact.getExecutableSharedParameterTypes(constructor))) { 3274 return constructor; 3275 } 3276 } 3277 throw new NoSuchMethodException(methodToString("<init>", parameterTypes)); 3278 } 3279 3280 // 3281 // Other helpers and base implementation 3282 // 3283 3284 private static boolean arrayContentsEq(Object[] a1, Object[] a2) { 3285 if (a1 == null) { 3286 return a2 == null || a2.length == 0; 3287 } 3288 3289 if (a2 == null) { 3290 return a1.length == 0; 3291 } 3292 3293 if (a1.length != a2.length) { 3294 return false; 3295 } 3296 3297 for (int i = 0; i < a1.length; i++) { 3298 if (a1[i] != a2[i]) { 3299 return false; 3300 } 3301 } 3302 3303 return true; 3304 } 3305 3306 private static Field[] copyFields(Field[] arg) { 3307 Field[] out = new Field[arg.length]; 3308 ReflectionFactory fact = getReflectionFactory(); 3309 for (int i = 0; i < arg.length; i++) { 3310 out[i] = fact.copyField(arg[i]); 3311 } 3312 return out; 3313 } 3314 3315 private static Method[] copyMethods(Method[] arg) { 3316 Method[] out = new Method[arg.length]; 3317 ReflectionFactory fact = getReflectionFactory(); 3318 for (int i = 0; i < arg.length; i++) { 3319 out[i] = fact.copyMethod(arg[i]); 3320 } 3321 return out; 3322 } 3323 3324 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) { 3325 Constructor<U>[] out = arg.clone(); 3326 ReflectionFactory fact = getReflectionFactory(); 3327 for (int i = 0; i < out.length; i++) { 3328 out[i] = fact.copyConstructor(out[i]); 3329 } 3330 return out; 3331 } 3332 3333 private native Field[] getDeclaredFields0(boolean publicOnly); 3334 private native Method[] getDeclaredMethods0(boolean publicOnly); 3335 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly); 3336 private native Class<?>[] getDeclaredClasses0(); 3337 3338 /* 3339 * Returns an array containing the components of the Record attribute, 3340 * or null if the attribute is not present. 3341 * 3342 * Note that this method returns non-null array on a class with 3343 * the Record attribute even if this class is not a record. 3344 */ 3345 private native RecordComponent[] getRecordComponents0(); 3346 private native boolean isRecord0(); 3347 3348 /** 3349 * Helper method to get the method name from arguments. 3350 */ 3351 private String methodToString(String name, Class<?>[] argTypes) { 3352 return getName() + '.' + name + 3353 ((argTypes == null || argTypes.length == 0) ? 3354 "()" : 3355 Arrays.stream(argTypes) 3356 .map(c -> c == null ? "null" : c.getName()) 3357 .collect(Collectors.joining(",", "(", ")"))); 3358 } 3359 3360 /** use serialVersionUID from JDK 1.1 for interoperability */ 3361 @java.io.Serial 3362 private static final long serialVersionUID = 3206093459760846163L; 3363 3364 3365 /** 3366 * Class Class is special cased within the Serialization Stream Protocol. 3367 * 3368 * A Class instance is written initially into an ObjectOutputStream in the 3369 * following format: 3370 * <pre> 3371 * {@code TC_CLASS} ClassDescriptor 3372 * A ClassDescriptor is a special cased serialization of 3373 * a {@code java.io.ObjectStreamClass} instance. 3374 * </pre> 3375 * A new handle is generated for the initial time the class descriptor 3376 * is written into the stream. Future references to the class descriptor 3377 * are written as references to the initial class descriptor instance. 3378 * 3379 * @see java.io.ObjectStreamClass 3380 */ 3381 @java.io.Serial 3382 private static final ObjectStreamField[] serialPersistentFields = 3383 new ObjectStreamField[0]; 3384 3385 3386 /** 3387 * Returns the assertion status that would be assigned to this 3388 * class if it were to be initialized at the time this method is invoked. 3389 * If this class has had its assertion status set, the most recent 3390 * setting will be returned; otherwise, if any package default assertion 3391 * status pertains to this class, the most recent setting for the most 3392 * specific pertinent package default assertion status is returned; 3393 * otherwise, if this class is not a system class (i.e., it has a 3394 * class loader) its class loader's default assertion status is returned; 3395 * otherwise, the system class default assertion status is returned. 3396 * 3397 * @apiNote 3398 * Few programmers will have any need for this method; it is provided 3399 * for the benefit of the JDK itself. (It allows a class to determine at 3400 * the time that it is initialized whether assertions should be enabled.) 3401 * Note that this method is not guaranteed to return the actual 3402 * assertion status that was (or will be) associated with the specified 3403 * class when it was (or will be) initialized. 3404 * 3405 * @return the desired assertion status of the specified class. 3406 * @see java.lang.ClassLoader#setClassAssertionStatus 3407 * @see java.lang.ClassLoader#setPackageAssertionStatus 3408 * @see java.lang.ClassLoader#setDefaultAssertionStatus 3409 * @since 1.4 3410 */ 3411 public boolean desiredAssertionStatus() { 3412 ClassLoader loader = classLoader; 3413 // If the loader is null this is a system class, so ask the VM 3414 if (loader == null) 3415 return desiredAssertionStatus0(this); 3416 3417 // If the classloader has been initialized with the assertion 3418 // directives, ask it. Otherwise, ask the VM. 3419 synchronized(loader.assertionLock) { 3420 if (loader.classAssertionStatus != null) { 3421 return loader.desiredAssertionStatus(getName()); 3422 } 3423 } 3424 return desiredAssertionStatus0(this); 3425 } 3426 3427 // Retrieves the desired assertion status of this class from the VM 3428 private static native boolean desiredAssertionStatus0(Class<?> clazz); 3429 3430 /** 3431 * Returns true if and only if this class was declared as an enum in the 3432 * source code. 3433 * 3434 * Note that {@link java.lang.Enum} is not itself an enum class. 3435 * 3436 * Also note that if an enum constant is declared with a class body, 3437 * the class of that enum constant object is an anonymous class 3438 * and <em>not</em> the class of the declaring enum class. The 3439 * {@link Enum#getDeclaringClass} method of an enum constant can 3440 * be used to get the class of the enum class declaring the 3441 * constant. 3442 * 3443 * @return true if and only if this class was declared as an enum in the 3444 * source code 3445 * @since 1.5 3446 * @jls 8.9.1 Enum Constants 3447 */ 3448 public boolean isEnum() { 3449 // An enum must both directly extend java.lang.Enum and have 3450 // the ENUM bit set; classes for specialized enum constants 3451 // don't do the former. 3452 return (this.getModifiers() & ENUM) != 0 && 3453 this.getSuperclass() == java.lang.Enum.class; 3454 } 3455 3456 /** 3457 * Returns {@code true} if and only if this class is a record class. 3458 * 3459 * <p> The {@linkplain #getSuperclass() direct superclass} of a record 3460 * class is {@code java.lang.Record}. A record class is {@linkplain 3461 * Modifier#FINAL final}. A record class has (possibly zero) record 3462 * components; {@link #getRecordComponents()} returns a non-null but 3463 * possibly empty value for a record. 3464 * 3465 * <p> Note that class {@link Record} is not a record class and thus 3466 * invoking this method on class {@code Record} returns {@code false}. 3467 * 3468 * @return true if and only if this class is a record class, otherwise false 3469 * @jls 8.10 Record Classes 3470 * @since 16 3471 */ 3472 public boolean isRecord() { 3473 // this superclass and final modifier check is not strictly necessary 3474 // they are intrinsified and serve as a fast-path check 3475 return getSuperclass() == java.lang.Record.class && 3476 (this.getModifiers() & Modifier.FINAL) != 0 && 3477 isRecord0(); 3478 } 3479 3480 // Fetches the factory for reflective objects 3481 private static ReflectionFactory getReflectionFactory() { 3482 var factory = reflectionFactory; 3483 if (factory != null) { 3484 return factory; 3485 } 3486 return reflectionFactory = ReflectionFactory.getReflectionFactory(); 3487 } 3488 private static ReflectionFactory reflectionFactory; 3489 3490 /** 3491 * When CDS is enabled, the Class class may be aot-initialized. However, 3492 * we can't archive reflectionFactory, so we reset it to null, so it 3493 * will be allocated again at runtime. 3494 */ 3495 private static void resetArchivedStates() { 3496 reflectionFactory = null; 3497 } 3498 3499 /** 3500 * Returns the elements of this enum class or null if this 3501 * Class object does not represent an enum class. 3502 * 3503 * @return an array containing the values comprising the enum class 3504 * represented by this {@code Class} object in the order they're 3505 * declared, or null if this {@code Class} object does not 3506 * represent an enum class 3507 * @since 1.5 3508 * @jls 8.9.1 Enum Constants 3509 */ 3510 public T[] getEnumConstants() { 3511 T[] values = getEnumConstantsShared(); 3512 return (values != null) ? values.clone() : null; 3513 } 3514 3515 /** 3516 * Returns the elements of this enum class or null if this 3517 * Class object does not represent an enum class; 3518 * identical to getEnumConstants except that the result is 3519 * uncloned, cached, and shared by all callers. 3520 */ 3521 T[] getEnumConstantsShared() { 3522 T[] constants = enumConstants; 3523 if (constants == null) { 3524 if (!isEnum()) return null; 3525 try { 3526 final Method values = getMethod("values"); 3527 values.setAccessible(true); 3528 @SuppressWarnings("unchecked") 3529 T[] temporaryConstants = (T[])values.invoke(null); 3530 enumConstants = constants = temporaryConstants; 3531 } 3532 // These can happen when users concoct enum-like classes 3533 // that don't comply with the enum spec. 3534 catch (InvocationTargetException | NoSuchMethodException | 3535 IllegalAccessException | NullPointerException | 3536 ClassCastException ex) { return null; } 3537 } 3538 return constants; 3539 } 3540 private transient volatile T[] enumConstants; 3541 3542 /** 3543 * Returns a map from simple name to enum constant. This package-private 3544 * method is used internally by Enum to implement 3545 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)} 3546 * efficiently. Note that the map is returned by this method is 3547 * created lazily on first use. Typically it won't ever get created. 3548 */ 3549 Map<String, T> enumConstantDirectory() { 3550 Map<String, T> directory = enumConstantDirectory; 3551 if (directory == null) { 3552 T[] universe = getEnumConstantsShared(); 3553 if (universe == null) 3554 throw new IllegalArgumentException( 3555 getName() + " is not an enum class"); 3556 directory = HashMap.newHashMap(universe.length); 3557 for (T constant : universe) { 3558 directory.put(((Enum<?>)constant).name(), constant); 3559 } 3560 enumConstantDirectory = directory; 3561 } 3562 return directory; 3563 } 3564 private transient volatile Map<String, T> enumConstantDirectory; 3565 3566 /** 3567 * Casts an object to the class or interface represented 3568 * by this {@code Class} object. 3569 * 3570 * @param obj the object to be cast 3571 * @return the object after casting, or null if obj is null 3572 * 3573 * @throws ClassCastException if the object is not 3574 * null and is not assignable to the type T. 3575 * 3576 * @since 1.5 3577 */ 3578 @SuppressWarnings("unchecked") 3579 @IntrinsicCandidate 3580 public T cast(Object obj) { 3581 if (obj != null && !isInstance(obj)) 3582 throw new ClassCastException(cannotCastMsg(obj)); 3583 return (T) obj; 3584 } 3585 3586 private String cannotCastMsg(Object obj) { 3587 return "Cannot cast " + obj.getClass().getName() + " to " + getName(); 3588 } 3589 3590 /** 3591 * Casts this {@code Class} object to represent a subclass of the class 3592 * represented by the specified class object. Checks that the cast 3593 * is valid, and throws a {@code ClassCastException} if it is not. If 3594 * this method succeeds, it always returns a reference to this {@code Class} object. 3595 * 3596 * <p>This method is useful when a client needs to "narrow" the type of 3597 * a {@code Class} object to pass it to an API that restricts the 3598 * {@code Class} objects that it is willing to accept. A cast would 3599 * generate a compile-time warning, as the correctness of the cast 3600 * could not be checked at runtime (because generic types are implemented 3601 * by erasure). 3602 * 3603 * @param <U> the type to cast this {@code Class} object to 3604 * @param clazz the class of the type to cast this {@code Class} object to 3605 * @return this {@code Class} object, cast to represent a subclass of 3606 * the specified class object. 3607 * @throws ClassCastException if this {@code Class} object does not 3608 * represent a subclass of the specified class (here "subclass" includes 3609 * the class itself). 3610 * @since 1.5 3611 */ 3612 @SuppressWarnings("unchecked") 3613 public <U> Class<? extends U> asSubclass(Class<U> clazz) { 3614 if (clazz.isAssignableFrom(this)) 3615 return (Class<? extends U>) this; 3616 else 3617 throw new ClassCastException(this.toString()); 3618 } 3619 3620 /** 3621 * {@inheritDoc} 3622 * <p>Note that any annotation returned by this method is a 3623 * declaration annotation. 3624 * 3625 * @throws NullPointerException {@inheritDoc} 3626 * @since 1.5 3627 */ 3628 @Override 3629 @SuppressWarnings("unchecked") 3630 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) { 3631 Objects.requireNonNull(annotationClass); 3632 3633 return (A) annotationData().annotations.get(annotationClass); 3634 } 3635 3636 /** 3637 * {@inheritDoc} 3638 * @throws NullPointerException {@inheritDoc} 3639 * @since 1.5 3640 */ 3641 @Override 3642 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) { 3643 return GenericDeclaration.super.isAnnotationPresent(annotationClass); 3644 } 3645 3646 /** 3647 * {@inheritDoc} 3648 * <p>Note that any annotations returned by this method are 3649 * declaration annotations. 3650 * 3651 * @throws NullPointerException {@inheritDoc} 3652 * @since 1.8 3653 */ 3654 @Override 3655 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) { 3656 Objects.requireNonNull(annotationClass); 3657 3658 AnnotationData annotationData = annotationData(); 3659 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations, 3660 this, 3661 annotationClass); 3662 } 3663 3664 /** 3665 * {@inheritDoc} 3666 * <p>Note that any annotations returned by this method are 3667 * declaration annotations. 3668 * 3669 * @since 1.5 3670 */ 3671 @Override 3672 public Annotation[] getAnnotations() { 3673 return AnnotationParser.toArray(annotationData().annotations); 3674 } 3675 3676 /** 3677 * {@inheritDoc} 3678 * <p>Note that any annotation returned by this method is a 3679 * declaration annotation. 3680 * 3681 * @throws NullPointerException {@inheritDoc} 3682 * @since 1.8 3683 */ 3684 @Override 3685 @SuppressWarnings("unchecked") 3686 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) { 3687 Objects.requireNonNull(annotationClass); 3688 3689 return (A) annotationData().declaredAnnotations.get(annotationClass); 3690 } 3691 3692 /** 3693 * {@inheritDoc} 3694 * <p>Note that any annotations returned by this method are 3695 * declaration annotations. 3696 * 3697 * @throws NullPointerException {@inheritDoc} 3698 * @since 1.8 3699 */ 3700 @Override 3701 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) { 3702 Objects.requireNonNull(annotationClass); 3703 3704 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations, 3705 annotationClass); 3706 } 3707 3708 /** 3709 * {@inheritDoc} 3710 * <p>Note that any annotations returned by this method are 3711 * declaration annotations. 3712 * 3713 * @since 1.5 3714 */ 3715 @Override 3716 public Annotation[] getDeclaredAnnotations() { 3717 return AnnotationParser.toArray(annotationData().declaredAnnotations); 3718 } 3719 3720 // annotation data that might get invalidated when JVM TI RedefineClasses() is called 3721 private static class AnnotationData { 3722 final Map<Class<? extends Annotation>, Annotation> annotations; 3723 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations; 3724 3725 // Value of classRedefinedCount when we created this AnnotationData instance 3726 final int redefinedCount; 3727 3728 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations, 3729 Map<Class<? extends Annotation>, Annotation> declaredAnnotations, 3730 int redefinedCount) { 3731 this.annotations = annotations; 3732 this.declaredAnnotations = declaredAnnotations; 3733 this.redefinedCount = redefinedCount; 3734 } 3735 } 3736 3737 // Annotations cache 3738 @SuppressWarnings("UnusedDeclaration") 3739 private transient volatile AnnotationData annotationData; 3740 3741 private AnnotationData annotationData() { 3742 while (true) { // retry loop 3743 AnnotationData annotationData = this.annotationData; 3744 int classRedefinedCount = this.classRedefinedCount; 3745 if (annotationData != null && 3746 annotationData.redefinedCount == classRedefinedCount) { 3747 return annotationData; 3748 } 3749 // null or stale annotationData -> optimistically create new instance 3750 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount); 3751 // try to install it 3752 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) { 3753 // successfully installed new AnnotationData 3754 return newAnnotationData; 3755 } 3756 } 3757 } 3758 3759 private AnnotationData createAnnotationData(int classRedefinedCount) { 3760 Map<Class<? extends Annotation>, Annotation> declaredAnnotations = 3761 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this); 3762 Class<?> superClass = getSuperclass(); 3763 Map<Class<? extends Annotation>, Annotation> annotations = null; 3764 if (superClass != null) { 3765 Map<Class<? extends Annotation>, Annotation> superAnnotations = 3766 superClass.annotationData().annotations; 3767 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) { 3768 Class<? extends Annotation> annotationClass = e.getKey(); 3769 if (AnnotationType.getInstance(annotationClass).isInherited()) { 3770 if (annotations == null) { // lazy construction 3771 annotations = LinkedHashMap.newLinkedHashMap(Math.max( 3772 declaredAnnotations.size(), 3773 Math.min(12, declaredAnnotations.size() + superAnnotations.size()) 3774 ) 3775 ); 3776 } 3777 annotations.put(annotationClass, e.getValue()); 3778 } 3779 } 3780 } 3781 if (annotations == null) { 3782 // no inherited annotations -> share the Map with declaredAnnotations 3783 annotations = declaredAnnotations; 3784 } else { 3785 // at least one inherited annotation -> declared may override inherited 3786 annotations.putAll(declaredAnnotations); 3787 } 3788 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount); 3789 } 3790 3791 // Annotation interfaces cache their internal (AnnotationType) form 3792 3793 @SuppressWarnings("UnusedDeclaration") 3794 private transient volatile AnnotationType annotationType; 3795 3796 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) { 3797 return Atomic.casAnnotationType(this, oldType, newType); 3798 } 3799 3800 AnnotationType getAnnotationType() { 3801 return annotationType; 3802 } 3803 3804 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() { 3805 return annotationData().declaredAnnotations; 3806 } 3807 3808 /* Backing store of user-defined values pertaining to this class. 3809 * Maintained by the ClassValue class. 3810 */ 3811 transient ClassValue.ClassValueMap classValueMap; 3812 3813 /** 3814 * Returns an {@code AnnotatedType} object that represents the use of a 3815 * type to specify the superclass of the entity represented by this {@code 3816 * Class} object. (The <em>use</em> of type Foo to specify the superclass 3817 * in '... extends Foo' is distinct from the <em>declaration</em> of class 3818 * Foo.) 3819 * 3820 * <p> If this {@code Class} object represents a class whose declaration 3821 * does not explicitly indicate an annotated superclass, then the return 3822 * value is an {@code AnnotatedType} object representing an element with no 3823 * annotations. 3824 * 3825 * <p> If this {@code Class} represents either the {@code Object} class, an 3826 * interface type, an array type, a primitive type, or void, the return 3827 * value is {@code null}. 3828 * 3829 * @return an object representing the superclass 3830 * @since 1.8 3831 */ 3832 public AnnotatedType getAnnotatedSuperclass() { 3833 if (this == Object.class || 3834 isInterface() || 3835 isArray() || 3836 isPrimitive() || 3837 this == Void.TYPE) { 3838 return null; 3839 } 3840 3841 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this); 3842 } 3843 3844 /** 3845 * Returns an array of {@code AnnotatedType} objects that represent the use 3846 * of types to specify superinterfaces of the entity represented by this 3847 * {@code Class} object. (The <em>use</em> of type Foo to specify a 3848 * superinterface in '... implements Foo' is distinct from the 3849 * <em>declaration</em> of interface Foo.) 3850 * 3851 * <p> If this {@code Class} object represents a class, the return value is 3852 * an array containing objects representing the uses of interface types to 3853 * specify interfaces implemented by the class. The order of the objects in 3854 * the array corresponds to the order of the interface types used in the 3855 * 'implements' clause of the declaration of this {@code Class} object. 3856 * 3857 * <p> If this {@code Class} object represents an interface, the return 3858 * value is an array containing objects representing the uses of interface 3859 * types to specify interfaces directly extended by the interface. The 3860 * order of the objects in the array corresponds to the order of the 3861 * interface types used in the 'extends' clause of the declaration of this 3862 * {@code Class} object. 3863 * 3864 * <p> If this {@code Class} object represents a class or interface whose 3865 * declaration does not explicitly indicate any annotated superinterfaces, 3866 * the return value is an array of length 0. 3867 * 3868 * <p> If this {@code Class} object represents either the {@code Object} 3869 * class, an array type, a primitive type, or void, the return value is an 3870 * array of length 0. 3871 * 3872 * @return an array representing the superinterfaces 3873 * @since 1.8 3874 */ 3875 public AnnotatedType[] getAnnotatedInterfaces() { 3876 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this); 3877 } 3878 3879 private native Class<?> getNestHost0(); 3880 3881 /** 3882 * Returns the nest host of the <a href=#nest>nest</a> to which the class 3883 * or interface represented by this {@code Class} object belongs. 3884 * Every class and interface belongs to exactly one nest. 3885 * 3886 * If the nest host of this class or interface has previously 3887 * been determined, then this method returns the nest host. 3888 * If the nest host of this class or interface has 3889 * not previously been determined, then this method determines the nest 3890 * host using the algorithm of JVMS 5.4.4, and returns it. 3891 * 3892 * Often, a class or interface belongs to a nest consisting only of itself, 3893 * in which case this method returns {@code this} to indicate that the class 3894 * or interface is the nest host. 3895 * 3896 * <p>If this {@code Class} object represents a primitive type, an array type, 3897 * or {@code void}, then this method returns {@code this}, 3898 * indicating that the represented entity belongs to the nest consisting only of 3899 * itself, and is the nest host. 3900 * 3901 * @return the nest host of this class or interface 3902 * 3903 * @since 11 3904 * @jvms 4.7.28 The {@code NestHost} Attribute 3905 * @jvms 4.7.29 The {@code NestMembers} Attribute 3906 * @jvms 5.4.4 Access Control 3907 */ 3908 public Class<?> getNestHost() { 3909 if (isPrimitive() || isArray()) { 3910 return this; 3911 } 3912 return getNestHost0(); 3913 } 3914 3915 /** 3916 * Determines if the given {@code Class} is a nestmate of the 3917 * class or interface represented by this {@code Class} object. 3918 * Two classes or interfaces are nestmates 3919 * if they have the same {@linkplain #getNestHost() nest host}. 3920 * 3921 * @param c the class to check 3922 * @return {@code true} if this class and {@code c} are members of 3923 * the same nest; and {@code false} otherwise. 3924 * 3925 * @since 11 3926 */ 3927 public boolean isNestmateOf(Class<?> c) { 3928 if (this == c) { 3929 return true; 3930 } 3931 if (isPrimitive() || isArray() || 3932 c.isPrimitive() || c.isArray()) { 3933 return false; 3934 } 3935 3936 return getNestHost() == c.getNestHost(); 3937 } 3938 3939 private native Class<?>[] getNestMembers0(); 3940 3941 /** 3942 * Returns an array containing {@code Class} objects representing all the 3943 * classes and interfaces that are members of the nest to which the class 3944 * or interface represented by this {@code Class} object belongs. 3945 * 3946 * First, this method obtains the {@linkplain #getNestHost() nest host}, 3947 * {@code H}, of the nest to which the class or interface represented by 3948 * this {@code Class} object belongs. The zeroth element of the returned 3949 * array is {@code H}. 3950 * 3951 * Then, for each class or interface {@code C} which is recorded by {@code H} 3952 * as being a member of its nest, this method attempts to obtain the {@code Class} 3953 * object for {@code C} (using {@linkplain #getClassLoader() the defining class 3954 * loader} of the current {@code Class} object), and then obtains the 3955 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs. 3956 * The classes and interfaces which are recorded by {@code H} as being members 3957 * of its nest, and for which {@code H} can be determined as their nest host, 3958 * are indicated by subsequent elements of the returned array. The order of 3959 * such elements is unspecified. Duplicates are permitted. 3960 * 3961 * <p>If this {@code Class} object represents a primitive type, an array type, 3962 * or {@code void}, then this method returns a single-element array containing 3963 * {@code this}. 3964 * 3965 * @apiNote 3966 * The returned array includes only the nest members recorded in the {@code NestMembers} 3967 * attribute, and not any hidden classes that were added to the nest via 3968 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 3969 * Lookup::defineHiddenClass}. 3970 * 3971 * @return an array of all classes and interfaces in the same nest as 3972 * this class or interface 3973 * 3974 * @since 11 3975 * @see #getNestHost() 3976 * @jvms 4.7.28 The {@code NestHost} Attribute 3977 * @jvms 4.7.29 The {@code NestMembers} Attribute 3978 */ 3979 public Class<?>[] getNestMembers() { 3980 if (isPrimitive() || isArray()) { 3981 return new Class<?>[] { this }; 3982 } 3983 Class<?>[] members = getNestMembers0(); 3984 // Can't actually enable this due to bootstrapping issues 3985 // assert(members.length != 1 || members[0] == this); // expected invariant from VM 3986 return members; 3987 } 3988 3989 /** 3990 * Returns the descriptor string of the entity (class, interface, array class, 3991 * primitive type, or {@code void}) represented by this {@code Class} object. 3992 * 3993 * <p> If this {@code Class} object represents a class or interface, 3994 * not an array class, then: 3995 * <ul> 3996 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden}, 3997 * then the result is a field descriptor (JVMS {@jvms 4.3.2}) 3998 * for the class or interface. Calling 3999 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor} 4000 * with the result descriptor string produces a {@link ClassDesc ClassDesc} 4001 * describing this class or interface. 4002 * <li> If the class or interface is {@linkplain Class#isHidden() hidden}, 4003 * then the result is a string of the form: 4004 * <blockquote> 4005 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"} 4006 * </blockquote> 4007 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name} 4008 * encoded in internal form indicated by the {@code class} file passed to 4009 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...) 4010 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name. 4011 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}. 4012 * The result string is not a type descriptor. 4013 * </ul> 4014 * 4015 * <p> If this {@code Class} object represents an array class, then 4016 * the result is a string consisting of one or more '{@code [}' characters 4017 * representing the depth of the array nesting, followed by the 4018 * descriptor string of the element type. 4019 * <ul> 4020 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class 4021 * or interface, then this array class can be described nominally. 4022 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor} 4023 * with the result descriptor string produces a {@link ClassDesc ClassDesc} 4024 * describing this array class. 4025 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or 4026 * interface, then this array class cannot be described nominally. 4027 * The result string is not a type descriptor. 4028 * </ul> 4029 * 4030 * <p> If this {@code Class} object represents a primitive type or 4031 * {@code void}, then the result is a field descriptor string which 4032 * is a one-letter code corresponding to a primitive type or {@code void} 4033 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}). 4034 * 4035 * @return the descriptor string for this {@code Class} object 4036 * @jvms 4.3.2 Field Descriptors 4037 * @since 12 4038 */ 4039 @Override 4040 public String descriptorString() { 4041 if (isPrimitive()) 4042 return Wrapper.forPrimitiveType(this).basicTypeString(); 4043 4044 if (isArray()) { 4045 return "[".concat(componentType.descriptorString()); 4046 } else if (isHidden()) { 4047 String name = getName(); 4048 int index = name.indexOf('/'); 4049 return new StringBuilder(name.length() + 2) 4050 .append('L') 4051 .append(name.substring(0, index).replace('.', '/')) 4052 .append('.') 4053 .append(name, index + 1, name.length()) 4054 .append(';') 4055 .toString(); 4056 } else { 4057 String name = getName().replace('.', '/'); 4058 return StringConcatHelper.concat("L", name, ";"); 4059 } 4060 } 4061 4062 /** 4063 * Returns the component type of this {@code Class}, if it describes 4064 * an array type, or {@code null} otherwise. 4065 * 4066 * @implSpec 4067 * Equivalent to {@link Class#getComponentType()}. 4068 * 4069 * @return a {@code Class} describing the component type, or {@code null} 4070 * if this {@code Class} does not describe an array type 4071 * @since 12 4072 */ 4073 @Override 4074 public Class<?> componentType() { 4075 return getComponentType(); 4076 } 4077 4078 /** 4079 * Returns a {@code Class} for an array type whose component type 4080 * is described by this {@linkplain Class}. 4081 * 4082 * @throws UnsupportedOperationException if this component type is {@linkplain 4083 * Void#TYPE void} or if the number of dimensions of the resulting array 4084 * type would exceed 255. 4085 * @return a {@code Class} describing the array type 4086 * @jvms 4.3.2 Field Descriptors 4087 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure 4088 * @since 12 4089 */ 4090 @Override 4091 public Class<?> arrayType() { 4092 try { 4093 return Array.newInstance(this, 0).getClass(); 4094 } catch (IllegalArgumentException iae) { 4095 throw new UnsupportedOperationException(iae); 4096 } 4097 } 4098 4099 /** 4100 * Returns a nominal descriptor for this instance, if one can be 4101 * constructed, or an empty {@link Optional} if one cannot be. 4102 * 4103 * @return An {@link Optional} containing the resulting nominal descriptor, 4104 * or an empty {@link Optional} if one cannot be constructed. 4105 * @since 12 4106 */ 4107 @Override 4108 public Optional<ClassDesc> describeConstable() { 4109 Class<?> c = isArray() ? elementType() : this; 4110 return c.isHidden() ? Optional.empty() 4111 : Optional.of(ConstantUtils.classDesc(this)); 4112 } 4113 4114 /** 4115 * Returns {@code true} if and only if the underlying class is a hidden class. 4116 * 4117 * @return {@code true} if and only if this class is a hidden class. 4118 * 4119 * @since 15 4120 * @see MethodHandles.Lookup#defineHiddenClass 4121 * @see Class##hiddenClasses Hidden Classes 4122 */ 4123 @IntrinsicCandidate 4124 public native boolean isHidden(); 4125 4126 /** 4127 * Returns an array containing {@code Class} objects representing the 4128 * direct subinterfaces or subclasses permitted to extend or 4129 * implement this class or interface if it is sealed. The order of such elements 4130 * is unspecified. The array is empty if this sealed class or interface has no 4131 * permitted subclass. If this {@code Class} object represents a primitive type, 4132 * {@code void}, an array type, or a class or interface that is not sealed, 4133 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}. 4134 * Conversely, if {@link #isSealed()} returns {@code true}, then this method 4135 * returns a non-null value. 4136 * 4137 * For each class or interface {@code C} which is recorded as a permitted 4138 * direct subinterface or subclass of this class or interface, 4139 * this method attempts to obtain the {@code Class} 4140 * object for {@code C} (using {@linkplain #getClassLoader() the defining class 4141 * loader} of the current {@code Class} object). 4142 * The {@code Class} objects which can be obtained and which are direct 4143 * subinterfaces or subclasses of this class or interface, 4144 * are indicated by elements of the returned array. If a {@code Class} object 4145 * cannot be obtained, it is silently ignored, and not included in the result 4146 * array. 4147 * 4148 * @return an array of {@code Class} objects of the permitted subclasses of this class 4149 * or interface, or {@code null} if this class or interface is not sealed. 4150 * 4151 * @jls 8.1 Class Declarations 4152 * @jls 9.1 Interface Declarations 4153 * @since 17 4154 */ 4155 public Class<?>[] getPermittedSubclasses() { 4156 Class<?>[] subClasses; 4157 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) { 4158 return null; 4159 } 4160 if (subClasses.length > 0) { 4161 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) { 4162 subClasses = Arrays.stream(subClasses) 4163 .filter(this::isDirectSubType) 4164 .toArray(s -> new Class<?>[s]); 4165 } 4166 } 4167 return subClasses; 4168 } 4169 4170 private boolean isDirectSubType(Class<?> c) { 4171 if (isInterface()) { 4172 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) { 4173 if (i == this) { 4174 return true; 4175 } 4176 } 4177 } else { 4178 return c.getSuperclass() == this; 4179 } 4180 return false; 4181 } 4182 4183 /** 4184 * Returns {@code true} if and only if this {@code Class} object represents 4185 * a sealed class or interface. If this {@code Class} object represents a 4186 * primitive type, {@code void}, or an array type, this method returns 4187 * {@code false}. A sealed class or interface has (possibly zero) permitted 4188 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but 4189 * possibly empty value for a sealed class or interface. 4190 * 4191 * @return {@code true} if and only if this {@code Class} object represents 4192 * a sealed class or interface. 4193 * 4194 * @jls 8.1 Class Declarations 4195 * @jls 9.1 Interface Declarations 4196 * @since 17 4197 */ 4198 public boolean isSealed() { 4199 if (isArray() || isPrimitive()) { 4200 return false; 4201 } 4202 return getPermittedSubclasses() != null; 4203 } 4204 4205 private native Class<?>[] getPermittedSubclasses0(); 4206 4207 /* 4208 * Return the class's major and minor class file version packed into an int. 4209 * The high order 16 bits contain the class's minor version. The low order 4210 * 16 bits contain the class's major version. 4211 * 4212 * If the class is an array type then the class file version of its element 4213 * type is returned. If the class is a primitive type then the latest class 4214 * file major version is returned and zero is returned for the minor version. 4215 */ 4216 /* package-private */ 4217 int getClassFileVersion() { 4218 Class<?> c = isArray() ? elementType() : this; 4219 return c.getClassFileVersion0(); 4220 } 4221 4222 private native int getClassFileVersion0(); 4223 4224 /** 4225 * Return the access flags as they were in the class's bytecode, including 4226 * the original setting of ACC_SUPER. 4227 * 4228 * If this {@code Class} object represents a primitive type or 4229 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and 4230 * {@code FINAL}. 4231 * If this {@code Class} object represents an array type, return 0. 4232 */ 4233 int getClassFileAccessFlags() { 4234 return classFileAccessFlags; 4235 } 4236 4237 // Validates the length of the class name and throws an exception if it exceeds the maximum allowed length. 4238 private static void validateClassNameLength(String name) throws ClassNotFoundException { 4239 if (!ModifiedUtf.isValidLengthInConstantPool(name)) { 4240 throw new ClassNotFoundException( 4241 "Class name length exceeds limit of " 4242 + ModifiedUtf.CONSTANT_POOL_UTF8_MAX_BYTES 4243 + ": " + name.substring(0,256) + "..."); 4244 } 4245 } 4246 }