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