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.Proxy;
51 import java.lang.reflect.RecordComponent;
52 import java.lang.reflect.Type;
53 import java.lang.reflect.TypeVariable;
54 import java.lang.constant.Constable;
55 import java.net.URL;
56 import java.security.AllPermission;
57 import java.security.Permissions;
58 import java.security.ProtectionDomain;
59 import java.util.ArrayList;
60 import java.util.Arrays;
61 import java.util.Collection;
62 import java.util.HashMap;
63 import java.util.LinkedHashMap;
64 import java.util.LinkedHashSet;
65 import java.util.List;
66 import java.util.Map;
67 import java.util.Objects;
68 import java.util.Optional;
69 import java.util.Set;
70 import java.util.stream.Collectors;
71
72 import jdk.internal.constant.ConstantUtils;
73 import jdk.internal.loader.BootLoader;
74 import jdk.internal.loader.BuiltinClassLoader;
75 import jdk.internal.misc.Unsafe;
76 import jdk.internal.module.Resources;
77 import jdk.internal.reflect.CallerSensitive;
78 import jdk.internal.reflect.CallerSensitiveAdapter;
79 import jdk.internal.reflect.ConstantPool;
80 import jdk.internal.reflect.Reflection;
81 import jdk.internal.reflect.ReflectionFactory;
82 import jdk.internal.vm.annotation.IntrinsicCandidate;
83 import jdk.internal.vm.annotation.Stable;
84
85 import sun.invoke.util.Wrapper;
86 import sun.reflect.generics.factory.CoreReflectionFactory;
87 import sun.reflect.generics.factory.GenericsFactory;
88 import sun.reflect.generics.repository.ClassRepository;
89 import sun.reflect.generics.repository.MethodRepository;
90 import sun.reflect.generics.repository.ConstructorRepository;
91 import sun.reflect.generics.scope.ClassScope;
92 import sun.reflect.annotation.*;
93
94 /**
95 * Instances of the class {@code Class} represent classes and
96 * interfaces in a running Java application. An enum class and a record
97 * class are kinds of class; an annotation interface is a kind of
98 * interface. Every array also belongs to a class that is reflected as
99 * a {@code Class} object that is shared by all arrays with the same
100 * element type and number of dimensions. The primitive Java types
101 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
102 * int}, {@code long}, {@code float}, and {@code double}), and the
103 * keyword {@code void} are also represented as {@code Class} objects.
104 *
105 * <p> {@code Class} has no public constructor. Instead a {@code Class}
106 * object is constructed automatically by the Java Virtual Machine when
107 * a class is derived from the bytes of a {@code class} file through
108 * the invocation of one of the following methods:
109 * <ul>
110 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
111 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
112 * java.lang.invoke.MethodHandles.Lookup::defineClass}
113 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
114 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
115 * </ul>
116 *
117 * <p> The methods of class {@code Class} expose many characteristics of a
118 * class or interface. Most characteristics are derived from the {@code class}
119 * file that the class loader passed to the Java Virtual Machine or
120 * from the {@code class} file passed to {@code Lookup::defineClass}
121 * or {@code Lookup::defineHiddenClass}.
122 * A few characteristics are determined by the class loading environment
123 * at run time, such as the module returned by {@link #getModule() getModule()}.
124 *
125 * <p> The following example uses a {@code Class} object to print the
126 * class name of an object:
127 *
128 * {@snippet lang="java" :
129 * void printClassName(Object obj) {
130 * System.out.println("The class of " + obj +
131 * " is " + obj.getClass().getName());
132 * }}
133 *
134 * It is also possible to get the {@code Class} object for a named
135 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
136 * (JLS {@jls 15.8.2}).
137 * For example:
138 *
139 * {@snippet lang="java" :
140 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
141 * }
142 *
143 * <p> Some methods of class {@code Class} expose whether the declaration of
144 * a class or interface in Java source code was <em>enclosed</em> within
145 * another declaration. Other methods describe how a class or interface
146 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
147 * classes and interfaces, in the same run-time package, that
148 * allow mutual access to their {@code private} members.
149 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
150 * (JVMS {@jvms 4.7.29}).
151 * One nestmate acts as the
152 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
153 * belong to the nest; each of them in turn records it as the nest host.
154 * The classes and interfaces which belong to a nest, including its host, are
155 * determined when
156 * {@code class} files are generated, for example, a Java compiler
157 * will typically record a top-level class as the host of a nest where the
158 * other members are the classes and interfaces whose declarations are
159 * enclosed within the top-level class declaration.
160 *
161 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
162 * A class or interface created by the invocation of
163 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
164 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
165 * class or interface.
166 * All kinds of class, including enum classes and record classes, may be
167 * hidden classes; all kinds of interface, including annotation interfaces,
168 * may be hidden interfaces.
169 *
170 * The {@linkplain #getName() name of a hidden class or interface} is
171 * not a {@linkplain ClassLoader##binary-name binary name},
172 * which means the following:
173 * <ul>
174 * <li>A hidden class or interface cannot be referenced by the constant pools
175 * of other classes and interfaces.
176 * <li>A hidden class or interface cannot be described in
177 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
178 * {@link #describeConstable() Class::describeConstable},
179 * {@link ClassDesc#of(String) ClassDesc::of}, or
180 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
181 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
182 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
183 * </ul>
184 *
185 * A hidden class or interface is never an array class, but may be
186 * the element type of an array. In all other respects, the fact that
187 * a class or interface is hidden has no bearing on the characteristics
188 * exposed by the methods of class {@code Class}.
189 *
190 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
191 *
192 * Conventionally, a Java compiler, starting from a source file for an
193 * implicitly declared class, say {@code HelloWorld.java}, creates a
194 * similarly-named {@code class} file, {@code HelloWorld.class}, where
195 * the class stored in that {@code class} file is named {@code
196 * "HelloWorld"}, matching the base names of the source and {@code
197 * class} files.
198 *
199 * For the {@code Class} object of an implicitly declared class {@code
200 * HelloWorld}, the methods to get the {@linkplain #getName name} and
201 * {@linkplain #getTypeName type name} return results
202 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
203 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
204 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
205 *
206 * @param <T> the type of the class modeled by this {@code Class}
207 * object. For example, the type of {@code String.class} is {@code
208 * Class<String>}. Use {@code Class<?>} if the class being modeled is
209 * unknown.
210 *
211 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
212 * @since 1.0
213 */
214 public final class Class<T> implements java.io.Serializable,
215 GenericDeclaration,
216 Type,
217 AnnotatedElement,
218 TypeDescriptor.OfField<Class<?>>,
219 Constable {
220 private static final int ANNOTATION= 0x00002000;
221 private static final int ENUM = 0x00004000;
222 private static final int SYNTHETIC = 0x00001000;
223
224 private static native void registerNatives();
225 static {
226 runtimeSetup();
227 }
228
229 // Called from JVM when loading an AOT cache
230 private static void runtimeSetup() {
231 registerNatives();
232 }
233
234 /*
235 * Private constructor. Only the Java Virtual Machine creates Class objects.
236 * This constructor is not used and prevents the default constructor being
237 * generated.
238 */
239 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim) {
240 // Initialize final field for classLoader. The initialization value of non-null
241 // prevents future JIT optimizations from assuming this final field is null.
242 // The following assignments are done directly by the VM without calling this constructor.
243 classLoader = loader;
244 componentType = arrayComponentType;
245 modifiers = mods;
246 protectionDomain = pd;
247 primitive = isPrim;
248 }
249
250 /**
251 * Converts the object to a string. The string representation is the
252 * string "class" or "interface", followed by a space, and then by the
253 * name of the class in the format returned by {@code getName}.
254 * If this {@code Class} object represents a primitive type,
255 * this method returns the name of the primitive type. If
256 * this {@code Class} object represents void this method returns
257 * "void". If this {@code Class} object represents an array type,
258 * this method returns "class " followed by {@code getName}.
259 *
260 * @return a string representation of this {@code Class} object.
261 */
262 public String toString() {
263 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
264 return kind.concat(getName());
265 }
266
267 /**
268 * Returns a string describing this {@code Class}, including
269 * information about modifiers, {@link #isSealed() sealed}/{@code
270 * non-sealed} status, and type parameters.
271 *
272 * The string is formatted as a list of type modifiers, if any,
273 * followed by the kind of type (empty string for primitive types
274 * and {@code class}, {@code enum}, {@code interface},
275 * {@code @interface}, or {@code record} as appropriate), followed
276 * by the type's name, followed by an angle-bracketed
277 * comma-separated list of the type's type parameters, if any,
278 * including informative bounds on the type parameters, if any.
279 *
280 * A space is used to separate modifiers from one another and to
281 * separate any modifiers from the kind of type. The modifiers
282 * occur in canonical order. If there are no type parameters, the
283 * type parameter list is elided.
284 *
285 * For an array type, the string starts with the type name,
286 * followed by an angle-bracketed comma-separated list of the
287 * type's type parameters, if any, followed by a sequence of
288 * {@code []} characters, one set of brackets per dimension of
289 * the array.
290 *
291 * <p>Note that since information about the runtime representation
292 * of a type is being generated, modifiers not present on the
293 * originating source code or illegal on the originating source
294 * code may be present.
295 *
296 * @return a string describing this {@code Class}, including
297 * information about modifiers and type parameters
298 *
299 * @since 1.8
300 */
301 public String toGenericString() {
302 if (isPrimitive()) {
303 return toString();
304 } else {
305 StringBuilder sb = new StringBuilder();
306 Class<?> component = this;
307 int arrayDepth = 0;
308
309 if (isArray()) {
310 do {
311 arrayDepth++;
312 component = component.getComponentType();
313 } while (component.isArray());
314 sb.append(component.getName());
315 } else {
316 // Class modifiers are a superset of interface modifiers
317 int modifiers = getModifiers() & Modifier.classModifiers();
318 if (modifiers != 0) {
319 sb.append(Modifier.toString(modifiers));
320 sb.append(' ');
321 }
322
323 // A class cannot be strictfp and sealed/non-sealed so
324 // it is sufficient to check for sealed-ness after all
325 // modifiers are printed.
326 addSealingInfo(modifiers, sb);
327
328 if (isAnnotation()) {
329 sb.append('@');
330 }
331 if (isInterface()) { // Note: all annotation interfaces are interfaces
332 sb.append("interface");
333 } else {
334 if (isEnum())
335 sb.append("enum");
336 else if (isRecord())
337 sb.append("record");
338 else
339 sb.append("class");
340 }
341 sb.append(' ');
342 sb.append(getName());
343 }
344
345 TypeVariable<?>[] typeparms = component.getTypeParameters();
346 if (typeparms.length > 0) {
347 sb.append(Arrays.stream(typeparms)
348 .map(Class::typeVarBounds)
349 .collect(Collectors.joining(",", "<", ">")));
350 }
351
352 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
353
354 return sb.toString();
355 }
356 }
357
358 private void addSealingInfo(int modifiers, StringBuilder sb) {
359 // A class can be final XOR sealed XOR non-sealed.
360 if (Modifier.isFinal(modifiers)) {
361 return; // no-op
362 } else {
363 if (isSealed()) {
364 sb.append("sealed ");
365 return;
366 } else {
367 // Check for sealed ancestor, which implies this class
368 // is non-sealed.
369 if (hasSealedAncestor(this)) {
370 sb.append("non-sealed ");
371 }
372 }
373 }
374 }
375
376 private boolean hasSealedAncestor(Class<?> clazz) {
377 // From JLS 8.1.1.2:
378 // "It is a compile-time error if a class has a sealed direct
379 // superclass or a sealed direct superinterface, and is not
380 // declared final, sealed, or non-sealed either explicitly or
381 // implicitly.
382 // Thus, an effect of the sealed keyword is to force all
383 // direct subclasses to explicitly declare whether they are
384 // final, sealed, or non-sealed. This avoids accidentally
385 // exposing a sealed class hierarchy to unwanted subclassing."
386
387 // Therefore, will just check direct superclass and
388 // superinterfaces.
389 var superclass = clazz.getSuperclass();
390 if (superclass != null && superclass.isSealed()) {
391 return true;
392 }
393 for (var superinterface : clazz.getInterfaces()) {
394 if (superinterface.isSealed()) {
395 return true;
396 }
397 }
398 return false;
399 }
400
401 static String typeVarBounds(TypeVariable<?> typeVar) {
402 Type[] bounds = typeVar.getBounds();
403 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
404 return typeVar.getName();
405 } else {
406 return typeVar.getName() + " extends " +
407 Arrays.stream(bounds)
408 .map(Type::getTypeName)
409 .collect(Collectors.joining(" & "));
410 }
411 }
412
413 /**
414 * Returns the {@code Class} object associated with the class or
415 * interface with the given string name. Invoking this method is
416 * equivalent to:
417 *
418 * {@snippet lang="java" :
419 * Class.forName(className, true, currentLoader)
420 * }
421 *
422 * where {@code currentLoader} denotes the defining class loader of
423 * the current class.
424 *
425 * <p> For example, the following code fragment returns the
426 * runtime {@code Class} object for the class named
427 * {@code java.lang.Thread}:
428 *
429 * {@snippet lang="java" :
430 * Class<?> t = Class.forName("java.lang.Thread");
431 * }
432 * <p>
433 * A call to {@code forName("X")} causes the class named
434 * {@code X} to be initialized.
435 *
436 * <p>
437 * In cases where this method is called from a context where there is no
438 * caller frame on the stack (e.g. when called directly from a JNI
439 * attached thread), the system class loader is used.
440 *
441 * @param className the {@linkplain ClassLoader##binary-name binary name}
442 * of the class or the string representing an array type
443 * @return the {@code Class} object for the class with the
444 * specified name.
445 * @throws LinkageError if the linkage fails
446 * @throws ExceptionInInitializerError if the initialization provoked
447 * by this method fails
448 * @throws ClassNotFoundException if the class cannot be located
449 *
450 * @jls 12.2 Loading of Classes and Interfaces
451 * @jls 12.3 Linking of Classes and Interfaces
452 * @jls 12.4 Initialization of Classes and Interfaces
453 */
454 @CallerSensitive
455 public static Class<?> forName(String className)
456 throws ClassNotFoundException {
457 Class<?> caller = Reflection.getCallerClass();
458 return forName(className, caller);
459 }
460
461 // Caller-sensitive adapter method for reflective invocation
462 @CallerSensitiveAdapter
463 private static Class<?> forName(String className, Class<?> caller)
464 throws ClassNotFoundException {
465 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
466 : ClassLoader.getClassLoader(caller);
467 if (loader instanceof BuiltinClassLoader bcl) {
468 if (bcl.usePositiveCache) {
469 Class<?> result = bcl.checkPositiveLookupCache(className);
470 if (result != null) {
471 return result;
472 }
473 }
474 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(className)) {
475 throw new ClassNotFoundException(className);
476 }
477 }
478 return forName0(className, true, loader, caller);
479 }
480
481 /**
482 * Returns the {@code Class} object associated with the class or
483 * interface with the given string name, using the given class loader.
484 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
485 * this method attempts to locate and load the class or interface. The specified
486 * class loader is used to load the class or interface. If the parameter
487 * {@code loader} is {@code null}, the class is loaded through the bootstrap
488 * class loader. The class is initialized only if the
489 * {@code initialize} parameter is {@code true} and if it has
490 * not been initialized earlier.
491 *
492 * <p> This method cannot be used to obtain any of the {@code Class} objects
493 * representing primitive types or void, hidden classes or interfaces,
494 * or array classes whose element type is a hidden class or interface.
495 * If {@code name} denotes a primitive type or void, for example {@code I},
496 * an attempt will be made to locate a user-defined class in the unnamed package
497 * whose name is {@code I} instead.
498 * To obtain a {@code Class} object for a named primitive type
499 * such as {@code int} or {@code long} use {@link
500 * #forPrimitiveName(String)}.
501 *
502 * <p> To obtain the {@code Class} object associated with an array class,
503 * the name consists of one or more {@code '['} representing the depth
504 * of the array nesting, followed by the element type as encoded in
505 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
506 *
507 * <p> Examples:
508 * {@snippet lang="java" :
509 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
510 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
511 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
512 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
513 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
514 * }
515 *
516 * <p> A call to {@code getName()} on the {@code Class} object returned
517 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
518 *
519 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
520 * named <i>N</i> to be loaded but not initialized regardless of the value
521 * of the {@code initialize} parameter.
522 *
523 * @apiNote
524 * This method throws errors related to loading, linking or initializing
525 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
526 * <cite>The Java Language Specification</cite>.
527 * In addition, this method does not check whether the requested class
528 * is accessible to its caller.
529 *
530 * @param name the {@linkplain ClassLoader##binary-name binary name}
531 * of the class or the string representing an array class
532 *
533 * @param initialize if {@code true} the class will be initialized
534 * (which implies linking). See Section {@jls
535 * 12.4} of <cite>The Java Language
536 * Specification</cite>.
537 * @param loader class loader from which the class must be loaded
538 * @return class object representing the desired class
539 *
540 * @throws LinkageError if the linkage fails
541 * @throws ExceptionInInitializerError if the initialization provoked
542 * by this method fails
543 * @throws ClassNotFoundException if the class cannot be located by
544 * the specified class loader
545 *
546 * @see java.lang.Class#forName(String)
547 * @see java.lang.ClassLoader
548 *
549 * @jls 12.2 Loading of Classes and Interfaces
550 * @jls 12.3 Linking of Classes and Interfaces
551 * @jls 12.4 Initialization of Classes and Interfaces
552 * @jls 13.1 The Form of a Binary
553 * @since 1.2
554 */
555 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
556 throws ClassNotFoundException
557 {
558 if (loader instanceof BuiltinClassLoader bcl) {
559 if (bcl.usePositiveCache) {
560 Class<?> result = bcl.checkPositiveLookupCache(name);
561 if (result != null) {
562 return result;
563 }
564 }
565 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(name)) {
566 throw new ClassNotFoundException(name);
567 }
568 }
569 return forName0(name, initialize, loader, null);
570 }
571
572 /** Called after security check for system loader access checks have been made. */
573 private static native Class<?> forName0(String name, boolean initialize,
574 ClassLoader loader,
575 Class<?> caller)
576 throws ClassNotFoundException;
577
578
579 /**
580 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
581 * binary name} in the given module.
582 *
583 * <p> This method attempts to locate and load the class or interface.
584 * It does not link the class, and does not run the class initializer.
585 * If the class is not found, this method returns {@code null}. </p>
586 *
587 * <p> If the class loader of the given module defines other modules and
588 * the given name is a class defined in a different module, this method
589 * returns {@code null} after the class is loaded. </p>
590 *
591 * <p> This method does not check whether the requested class is
592 * accessible to its caller. </p>
593 *
594 * @apiNote
595 * This method does not support loading of array types, unlike
596 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
597 * a binary name. This method returns {@code null} on failure rather than
598 * throwing a {@link ClassNotFoundException}, as is done by
599 * the {@link #forName(String, boolean, ClassLoader)} method.
600 *
601 * @param module A module
602 * @param name The {@linkplain ClassLoader##binary-name binary name}
603 * of the class
604 * @return {@code Class} object of the given name defined in the given module;
605 * {@code null} if not found.
606 *
607 * @throws NullPointerException if the given module or name is {@code null}
608 *
609 * @throws LinkageError if the linkage fails
610 *
611 * @jls 12.2 Loading of Classes and Interfaces
612 * @jls 12.3 Linking of Classes and Interfaces
613 * @since 9
614 */
615 public static Class<?> forName(Module module, String name) {
616 Objects.requireNonNull(module);
617 Objects.requireNonNull(name);
618
619 ClassLoader cl = module.getClassLoader();
620 if (cl != null) {
621 return cl.loadClass(module, name);
622 } else {
623 return BootLoader.loadClass(module, name);
624 }
625 }
626
627 /**
628 * {@return the {@code Class} object associated with the
629 * {@linkplain #isPrimitive() primitive type} of the given name}
630 * If the argument is not the name of a primitive type, {@code
631 * null} is returned.
632 *
633 * @param primitiveName the name of the primitive type to find
634 *
635 * @throws NullPointerException if the argument is {@code null}
636 *
637 * @jls 4.2 Primitive Types and Values
638 * @jls 15.8.2 Class Literals
639 * @since 22
640 */
641 public static Class<?> forPrimitiveName(String primitiveName) {
642 return switch(primitiveName) {
643 // Integral types
644 case "int" -> int.class;
645 case "long" -> long.class;
646 case "short" -> short.class;
647 case "char" -> char.class;
648 case "byte" -> byte.class;
649
650 // Floating-point types
651 case "float" -> float.class;
652 case "double" -> double.class;
653
654 // Other types
655 case "boolean" -> boolean.class;
656 case "void" -> void.class;
657
658 default -> null;
659 };
660 }
661
662 /**
663 * Creates a new instance of the class represented by this {@code Class}
664 * object. The class is instantiated as if by a {@code new}
665 * expression with an empty argument list. The class is initialized if it
666 * has not already been initialized.
667 *
668 * @deprecated This method propagates any exception thrown by the
669 * nullary constructor, including a checked exception. Use of
670 * this method effectively bypasses the compile-time exception
671 * checking that would otherwise be performed by the compiler.
672 * The {@link
673 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
674 * Constructor.newInstance} method avoids this problem by wrapping
675 * any exception thrown by the constructor in a (checked) {@link
676 * java.lang.reflect.InvocationTargetException}.
677 *
678 * <p>The call
679 *
680 * {@snippet lang="java" :
681 * clazz.newInstance()
682 * }
683 *
684 * can be replaced by
685 *
686 * {@snippet lang="java" :
687 * clazz.getDeclaredConstructor().newInstance()
688 * }
689 *
690 * The latter sequence of calls is inferred to be able to throw
691 * the additional exception types {@link
692 * InvocationTargetException} and {@link
693 * NoSuchMethodException}. Both of these exception types are
694 * subclasses of {@link ReflectiveOperationException}.
695 *
696 * @return a newly allocated instance of the class represented by this
697 * object.
698 * @throws IllegalAccessException if the class or its nullary
699 * constructor is not accessible.
700 * @throws InstantiationException
701 * if this {@code Class} represents an abstract class,
702 * an interface, an array class, a primitive type, or void;
703 * or if the class has no nullary constructor;
704 * or if the instantiation fails for some other reason.
705 * @throws ExceptionInInitializerError if the initialization
706 * provoked by this method fails.
707 */
708 @CallerSensitive
709 @Deprecated(since="9")
710 public T newInstance()
711 throws InstantiationException, IllegalAccessException
712 {
713 // Constructor lookup
714 Constructor<T> tmpConstructor = cachedConstructor;
715 if (tmpConstructor == null) {
716 if (this == Class.class) {
717 throw new IllegalAccessException(
718 "Can not call newInstance() on the Class for java.lang.Class"
719 );
720 }
721 try {
722 Class<?>[] empty = {};
723 final Constructor<T> c = getReflectionFactory().copyConstructor(
724 getConstructor0(empty, Member.DECLARED));
725 // Disable accessibility checks on the constructor
726 // access check is done with the true caller
727 c.setAccessible(true);
728 cachedConstructor = tmpConstructor = c;
729 } catch (NoSuchMethodException e) {
730 throw (InstantiationException)
731 new InstantiationException(getName()).initCause(e);
732 }
733 }
734
735 try {
736 Class<?> caller = Reflection.getCallerClass();
737 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
738 } catch (InvocationTargetException e) {
739 Unsafe.getUnsafe().throwException(e.getTargetException());
740 // Not reached
741 return null;
742 }
743 }
744
745 private transient volatile Constructor<T> cachedConstructor;
746
747 /**
748 * Determines if the specified {@code Object} is assignment-compatible
749 * with the object represented by this {@code Class}. This method is
750 * the dynamic equivalent of the Java language {@code instanceof}
751 * operator. The method returns {@code true} if the specified
752 * {@code Object} argument is non-null and can be cast to the
753 * reference type represented by this {@code Class} object without
754 * raising a {@code ClassCastException.} It returns {@code false}
755 * otherwise.
756 *
757 * <p> Specifically, if this {@code Class} object represents a
758 * declared class, this method returns {@code true} if the specified
759 * {@code Object} argument is an instance of the represented class (or
760 * of any of its subclasses); it returns {@code false} otherwise. If
761 * this {@code Class} object represents an array class, this method
762 * returns {@code true} if the specified {@code Object} argument
763 * can be converted to an object of the array class by an identity
764 * conversion or by a widening reference conversion; it returns
765 * {@code false} otherwise. If this {@code Class} object
766 * represents an interface, this method returns {@code true} if the
767 * class or any superclass of the specified {@code Object} argument
768 * implements this interface; it returns {@code false} otherwise. If
769 * this {@code Class} object represents a primitive type, this method
770 * returns {@code false}.
771 *
772 * @param obj the object to check
773 * @return true if {@code obj} is an instance of this class
774 *
775 * @since 1.1
776 */
777 @IntrinsicCandidate
778 public native boolean isInstance(Object obj);
779
780
781 /**
782 * Determines if the class or interface represented by this
783 * {@code Class} object is either the same as, or is a superclass or
784 * superinterface of, the class or interface represented by the specified
785 * {@code Class} parameter. It returns {@code true} if so;
786 * otherwise it returns {@code false}. If this {@code Class}
787 * object represents a primitive type, this method returns
788 * {@code true} if the specified {@code Class} parameter is
789 * exactly this {@code Class} object; otherwise it returns
790 * {@code false}.
791 *
792 * <p> Specifically, this method tests whether the type represented by the
793 * specified {@code Class} parameter can be converted to the type
794 * represented by this {@code Class} object via an identity conversion
795 * or via a widening reference conversion. See <cite>The Java Language
796 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
797 * for details.
798 *
799 * @param cls the {@code Class} object to be checked
800 * @return the {@code boolean} value indicating whether objects of the
801 * type {@code cls} can be assigned to objects of this class
802 * @throws NullPointerException if the specified Class parameter is
803 * null.
804 * @since 1.1
805 */
806 @IntrinsicCandidate
807 public native boolean isAssignableFrom(Class<?> cls);
808
809
810 /**
811 * Determines if this {@code Class} object represents an
812 * interface type.
813 *
814 * @return {@code true} if this {@code Class} object represents an interface;
815 * {@code false} otherwise.
816 */
817 public boolean isInterface() {
818 return Modifier.isInterface(modifiers);
819 }
820
821
822 /**
823 * Determines if this {@code Class} object represents an array class.
824 *
825 * @return {@code true} if this {@code Class} object represents an array class;
826 * {@code false} otherwise.
827 * @since 1.1
828 */
829 public boolean isArray() {
830 return componentType != null;
831 }
832
833
834 /**
835 * Determines if this {@code Class} object represents a primitive
836 * type or void.
837 *
838 * <p> There are nine predefined {@code Class} objects to
839 * represent the eight primitive types and void. These are
840 * created by the Java Virtual Machine, and have the same
841 * {@linkplain #getName() names} as the primitive types that they
842 * represent, namely {@code boolean}, {@code byte}, {@code char},
843 * {@code short}, {@code int}, {@code long}, {@code float}, and
844 * {@code double}.
845 *
846 * <p>No other class objects are considered primitive.
847 *
848 * @apiNote
849 * A {@code Class} object represented by a primitive type can be
850 * accessed via the {@code TYPE} public static final variables
851 * defined in the primitive wrapper classes such as {@link
852 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
853 * language, the objects may be referred to by a class literal
854 * expression such as {@code int.class}. The {@code Class} object
855 * for void can be expressed as {@code void.class} or {@link
856 * java.lang.Void#TYPE Void.TYPE}.
857 *
858 * @return true if and only if this class represents a primitive type
859 *
860 * @see java.lang.Boolean#TYPE
861 * @see java.lang.Character#TYPE
862 * @see java.lang.Byte#TYPE
863 * @see java.lang.Short#TYPE
864 * @see java.lang.Integer#TYPE
865 * @see java.lang.Long#TYPE
866 * @see java.lang.Float#TYPE
867 * @see java.lang.Double#TYPE
868 * @see java.lang.Void#TYPE
869 * @since 1.1
870 * @jls 15.8.2 Class Literals
871 */
872 public boolean isPrimitive() {
873 return primitive;
874 }
875
876 /**
877 * Returns true if this {@code Class} object represents an annotation
878 * interface. Note that if this method returns true, {@link #isInterface()}
879 * would also return true, as all annotation interfaces are also interfaces.
880 *
881 * @return {@code true} if this {@code Class} object represents an annotation
882 * interface; {@code false} otherwise
883 * @since 1.5
884 */
885 public boolean isAnnotation() {
886 return (getModifiers() & ANNOTATION) != 0;
887 }
888
889 /**
890 *{@return {@code true} if and only if this class has the synthetic modifier
891 * bit set}
892 *
893 * @jls 13.1 The Form of a Binary
894 * @jvms 4.1 The {@code ClassFile} Structure
895 * @see <a
896 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
897 * programming language and JVM modeling in core reflection</a>
898 * @since 1.5
899 */
900 public boolean isSynthetic() {
901 return (getModifiers() & SYNTHETIC) != 0;
902 }
903
904 /**
905 * Returns the name of the entity (class, interface, array class,
906 * primitive type, or void) represented by this {@code Class} object.
907 *
908 * <p> If this {@code Class} object represents a class or interface,
909 * not an array class, then:
910 * <ul>
911 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
912 * then the {@linkplain ClassLoader##binary-name binary name}
913 * of the class or interface is returned.
914 * <li> If the class or interface is hidden, then the result is a string
915 * of the form: {@code N + '/' + <suffix>}
916 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
917 * indicated by the {@code class} file passed to
918 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
919 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
920 * </ul>
921 *
922 * <p> If this {@code Class} object represents an array class, then
923 * the result is a string consisting of one or more '{@code [}' characters
924 * representing the depth of the array nesting, followed by the element
925 * type as encoded using the following table:
926 *
927 * <blockquote><table class="striped" id="nameFormat">
928 * <caption style="display:none">Element types and encodings</caption>
929 * <thead>
930 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
931 * </thead>
932 * <tbody style="text-align:left">
933 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
934 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
935 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
936 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
937 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
938 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
939 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
940 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
941 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
942 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
943 * </tbody>
944 * </table></blockquote>
945 *
946 * <p> If this {@code Class} object represents a primitive type or {@code void},
947 * then the result is a string with the same spelling as the Java language
948 * keyword which corresponds to the primitive type or {@code void}.
949 *
950 * <p> Examples:
951 * <blockquote><pre>
952 * String.class.getName()
953 * returns "java.lang.String"
954 * Character.UnicodeBlock.class.getName()
955 * returns "java.lang.Character$UnicodeBlock"
956 * byte.class.getName()
957 * returns "byte"
958 * (new Object[3]).getClass().getName()
959 * returns "[Ljava.lang.Object;"
960 * (new int[3][4][5][6][7][8][9]).getClass().getName()
961 * returns "[[[[[[[I"
962 * </pre></blockquote>
963 *
964 * @apiNote
965 * Distinct class objects can have the same name but different class loaders.
966 *
967 * @return the name of the class, interface, or other entity
968 * represented by this {@code Class} object.
969 * @jls 13.1 The Form of a Binary
970 */
971 public String getName() {
972 String name = this.name;
973 return name != null ? name : initClassName();
974 }
975
976 // Cache the name to reduce the number of calls into the VM.
977 // This field would be set by VM itself during initClassName call.
978 private transient String name;
979 private native String initClassName();
980
981 /**
982 * Returns the class loader for the class. Some implementations may use
983 * null to represent the bootstrap class loader. This method will return
984 * null in such implementations if this class was loaded by the bootstrap
985 * class loader.
986 *
987 * <p>If this {@code Class} object
988 * represents a primitive type or void, null is returned.
989 *
990 * @return the class loader that loaded the class or interface
991 * represented by this {@code Class} object.
992 * @see java.lang.ClassLoader
993 */
994 public ClassLoader getClassLoader() {
995 return classLoader;
996 }
997
998 // Package-private to allow ClassLoader access
999 ClassLoader getClassLoader0() { return classLoader; }
1000
1001 /**
1002 * Returns the module that this class or interface is a member of.
1003 *
1004 * If this class represents an array type then this method returns the
1005 * {@code Module} for the element type. If this class represents a
1006 * primitive type or void, then the {@code Module} object for the
1007 * {@code java.base} module is returned.
1008 *
1009 * If this class is in an unnamed module then the {@linkplain
1010 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1011 * loader for this class is returned.
1012 *
1013 * @return the module that this class or interface is a member of
1014 *
1015 * @since 9
1016 */
1017 public Module getModule() {
1018 return module;
1019 }
1020
1021 // set by VM
1022 @Stable
1023 private transient Module module;
1024
1025 // Initialized in JVM not by private constructor
1026 // This field is filtered from reflection access, i.e. getDeclaredField
1027 // will throw NoSuchFieldException
1028 private final ClassLoader classLoader;
1029
1030 private transient Object classData; // Set by VM
1031 private transient Object[] signers; // Read by VM, mutable
1032 private final transient char modifiers; // Set by the VM
1033 private final transient boolean primitive; // Set by the VM if the Class is a primitive type.
1034
1035 // package-private
1036 Object getClassData() {
1037 return classData;
1038 }
1039
1040 /**
1041 * Returns an array of {@code TypeVariable} objects that represent the
1042 * type variables declared by the generic declaration represented by this
1043 * {@code GenericDeclaration} object, in declaration order. Returns an
1044 * array of length 0 if the underlying generic declaration declares no type
1045 * variables.
1046 *
1047 * @return an array of {@code TypeVariable} objects that represent
1048 * the type variables declared by this generic declaration
1049 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1050 * signature of this generic declaration does not conform to
1051 * the format specified in section {@jvms 4.7.9} of
1052 * <cite>The Java Virtual Machine Specification</cite>
1053 * @since 1.5
1054 */
1055 @SuppressWarnings("unchecked")
1056 public TypeVariable<Class<T>>[] getTypeParameters() {
1057 ClassRepository info = getGenericInfo();
1058 if (info != null)
1059 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1060 else
1061 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1062 }
1063
1064
1065 /**
1066 * Returns the {@code Class} representing the direct superclass of the
1067 * entity (class, interface, primitive type or void) represented by
1068 * this {@code Class}. If this {@code Class} represents either the
1069 * {@code Object} class, an interface, a primitive type, or void, then
1070 * null is returned. If this {@code Class} object represents an array class
1071 * then the {@code Class} object representing the {@code Object} class is
1072 * returned.
1073 *
1074 * @return the direct superclass of the class represented by this {@code Class} object
1075 */
1076 @IntrinsicCandidate
1077 public native Class<? super T> getSuperclass();
1078
1079
1080 /**
1081 * Returns the {@code Type} representing the direct superclass of
1082 * the entity (class, interface, primitive type or void) represented by
1083 * this {@code Class} object.
1084 *
1085 * <p>If the superclass is a parameterized type, the {@code Type}
1086 * object returned must accurately reflect the actual type
1087 * arguments used in the source code. The parameterized type
1088 * representing the superclass is created if it had not been
1089 * created before. See the declaration of {@link
1090 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1091 * semantics of the creation process for parameterized types. If
1092 * this {@code Class} object represents either the {@code Object}
1093 * class, an interface, a primitive type, or void, then null is
1094 * returned. If this {@code Class} object represents an array class
1095 * then the {@code Class} object representing the {@code Object} class is
1096 * returned.
1097 *
1098 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1099 * class signature does not conform to the format specified in
1100 * section {@jvms 4.7.9} of <cite>The Java Virtual
1101 * Machine Specification</cite>
1102 * @throws TypeNotPresentException if the generic superclass
1103 * refers to a non-existent type declaration
1104 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1105 * generic superclass refers to a parameterized type that cannot be
1106 * instantiated for any reason
1107 * @return the direct superclass of the class represented by this {@code Class} object
1108 * @since 1.5
1109 */
1110 public Type getGenericSuperclass() {
1111 ClassRepository info = getGenericInfo();
1112 if (info == null) {
1113 return getSuperclass();
1114 }
1115
1116 // Historical irregularity:
1117 // Generic signature marks interfaces with superclass = Object
1118 // but this API returns null for interfaces
1119 if (isInterface()) {
1120 return null;
1121 }
1122
1123 return info.getSuperclass();
1124 }
1125
1126 /**
1127 * Gets the package of this class.
1128 *
1129 * <p>If this class represents an array type, a primitive type or void,
1130 * this method returns {@code null}.
1131 *
1132 * @return the package of this class.
1133 */
1134 public Package getPackage() {
1135 if (isPrimitive() || isArray()) {
1136 return null;
1137 }
1138 ClassLoader cl = classLoader;
1139 return cl != null ? cl.definePackage(this)
1140 : BootLoader.definePackage(this);
1141 }
1142
1143 /**
1144 * Returns the fully qualified package name.
1145 *
1146 * <p> If this class is a top level class, then this method returns the fully
1147 * qualified name of the package that the class is a member of, or the
1148 * empty string if the class is in an unnamed package.
1149 *
1150 * <p> If this class is a member class, then this method is equivalent to
1151 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1152 * enclosing class}.
1153 *
1154 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1155 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1156 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1157 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1158 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1159 *
1160 * <p> If this class represents an array type then this method returns the
1161 * package name of the element type. If this class represents a primitive
1162 * type or void then the package name "{@code java.lang}" is returned.
1163 *
1164 * @return the fully qualified package name
1165 *
1166 * @since 9
1167 * @jls 6.7 Fully Qualified Names and Canonical Names
1168 */
1169 public String getPackageName() {
1170 String pn = this.packageName;
1171 if (pn == null) {
1172 Class<?> c = isArray() ? elementType() : this;
1173 if (c.isPrimitive()) {
1174 pn = "java.lang";
1175 } else {
1176 String cn = c.getName();
1177 int dot = cn.lastIndexOf('.');
1178 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1179 }
1180 this.packageName = pn;
1181 }
1182 return pn;
1183 }
1184
1185 // cached package name
1186 private transient String packageName;
1187
1188 /**
1189 * Returns the interfaces directly implemented by the class or interface
1190 * represented by this {@code Class} object.
1191 *
1192 * <p>If this {@code Class} object represents a class, the return value is an array
1193 * containing objects representing all interfaces directly implemented by
1194 * the class. The order of the interface objects in the array corresponds
1195 * to the order of the interface names in the {@code implements} clause of
1196 * the declaration of the class represented by this {@code Class} object. For example,
1197 * given the declaration:
1198 * <blockquote>
1199 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1200 * </blockquote>
1201 * suppose the value of {@code s} is an instance of
1202 * {@code Shimmer}; the value of the expression:
1203 * <blockquote>
1204 * {@code s.getClass().getInterfaces()[0]}
1205 * </blockquote>
1206 * is the {@code Class} object that represents interface
1207 * {@code FloorWax}; and the value of:
1208 * <blockquote>
1209 * {@code s.getClass().getInterfaces()[1]}
1210 * </blockquote>
1211 * is the {@code Class} object that represents interface
1212 * {@code DessertTopping}.
1213 *
1214 * <p>If this {@code Class} object represents an interface, the array contains objects
1215 * representing all interfaces directly extended by the interface. The
1216 * order of the interface objects in the array corresponds to the order of
1217 * the interface names in the {@code extends} clause of the declaration of
1218 * the interface represented by this {@code Class} object.
1219 *
1220 * <p>If this {@code Class} object represents a class or interface that implements no
1221 * interfaces, the method returns an array of length 0.
1222 *
1223 * <p>If this {@code Class} object represents a primitive type or void, the method
1224 * returns an array of length 0.
1225 *
1226 * <p>If this {@code Class} object represents an array type, the
1227 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1228 * returned in that order.
1229 *
1230 * @return an array of interfaces directly implemented by this class
1231 */
1232 public Class<?>[] getInterfaces() {
1233 // defensively copy before handing over to user code
1234 return getInterfaces(true);
1235 }
1236
1237 private Class<?>[] getInterfaces(boolean cloneArray) {
1238 ReflectionData<T> rd = reflectionData();
1239 Class<?>[] interfaces = rd.interfaces;
1240 if (interfaces == null) {
1241 interfaces = getInterfaces0();
1242 rd.interfaces = interfaces;
1243 }
1244 // defensively copy if requested
1245 return cloneArray ? interfaces.clone() : interfaces;
1246 }
1247
1248 private native Class<?>[] getInterfaces0();
1249
1250 /**
1251 * Returns the {@code Type}s representing the interfaces
1252 * directly implemented by the class or interface represented by
1253 * this {@code Class} object.
1254 *
1255 * <p>If a superinterface is a parameterized type, the
1256 * {@code Type} object returned for it must accurately reflect
1257 * the actual type arguments used in the source code. The
1258 * parameterized type representing each superinterface is created
1259 * if it had not been created before. See the declaration of
1260 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1261 * for the semantics of the creation process for parameterized
1262 * types.
1263 *
1264 * <p>If this {@code Class} object represents a class, the return value is an array
1265 * containing objects representing all interfaces directly implemented by
1266 * the class. The order of the interface objects in the array corresponds
1267 * to the order of the interface names in the {@code implements} clause of
1268 * the declaration of the class represented by this {@code Class} object.
1269 *
1270 * <p>If this {@code Class} object represents an interface, the array contains objects
1271 * representing all interfaces directly extended by the interface. The
1272 * order of the interface objects in the array corresponds to the order of
1273 * the interface names in the {@code extends} clause of the declaration of
1274 * the interface represented by this {@code Class} object.
1275 *
1276 * <p>If this {@code Class} object represents a class or interface that implements no
1277 * interfaces, the method returns an array of length 0.
1278 *
1279 * <p>If this {@code Class} object represents a primitive type or void, the method
1280 * returns an array of length 0.
1281 *
1282 * <p>If this {@code Class} object represents an array type, the
1283 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1284 * returned in that order.
1285 *
1286 * @throws java.lang.reflect.GenericSignatureFormatError
1287 * if the generic class signature does not conform to the
1288 * format specified in section {@jvms 4.7.9} of <cite>The
1289 * Java Virtual Machine Specification</cite>
1290 * @throws TypeNotPresentException if any of the generic
1291 * superinterfaces refers to a non-existent type declaration
1292 * @throws java.lang.reflect.MalformedParameterizedTypeException
1293 * if any of the generic superinterfaces refer to a parameterized
1294 * type that cannot be instantiated for any reason
1295 * @return an array of interfaces directly implemented by this class
1296 * @since 1.5
1297 */
1298 public Type[] getGenericInterfaces() {
1299 ClassRepository info = getGenericInfo();
1300 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1301 }
1302
1303
1304 /**
1305 * Returns the {@code Class} representing the component type of an
1306 * array. If this class does not represent an array class this method
1307 * returns null.
1308 *
1309 * @return the {@code Class} representing the component type of this
1310 * class if this class is an array
1311 * @see java.lang.reflect.Array
1312 * @since 1.1
1313 */
1314 public Class<?> getComponentType() {
1315 return componentType;
1316 }
1317
1318 // The componentType field's null value is the sole indication that the class
1319 // is an array - see isArray().
1320 private transient final Class<?> componentType;
1321
1322 /*
1323 * Returns the {@code Class} representing the element type of an array class.
1324 * If this class does not represent an array class, then this method returns
1325 * {@code null}.
1326 */
1327 private Class<?> elementType() {
1328 if (!isArray()) return null;
1329
1330 Class<?> c = this;
1331 while (c.isArray()) {
1332 c = c.getComponentType();
1333 }
1334 return c;
1335 }
1336
1337 /**
1338 * Returns the Java language modifiers for this class or interface, encoded
1339 * in an integer. The modifiers consist of the Java Virtual Machine's
1340 * constants for {@code public}, {@code protected},
1341 * {@code private}, {@code final}, {@code static},
1342 * {@code abstract} and {@code interface}; they should be decoded
1343 * using the methods of class {@code Modifier}.
1344 *
1345 * <p> If the underlying class is an array class:
1346 * <ul>
1347 * <li> its {@code public}, {@code private} and {@code protected}
1348 * modifiers are the same as those of its component type
1349 * <li> its {@code abstract} and {@code final} modifiers are always
1350 * {@code true}
1351 * <li> its interface modifier is always {@code false}, even when
1352 * the component type is an interface
1353 * </ul>
1354 * If this {@code Class} object represents a primitive type or
1355 * void, its {@code public}, {@code abstract}, and {@code final}
1356 * modifiers are always {@code true}.
1357 * For {@code Class} objects representing void, primitive types, and
1358 * arrays, the values of other modifiers are {@code false} other
1359 * than as specified above.
1360 *
1361 * <p> The modifier encodings are defined in section {@jvms 4.1}
1362 * of <cite>The Java Virtual Machine Specification</cite>.
1363 *
1364 * @return the {@code int} representing the modifiers for this class
1365 * @see java.lang.reflect.Modifier
1366 * @see #accessFlags()
1367 * @see <a
1368 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1369 * programming language and JVM modeling in core reflection</a>
1370 * @since 1.1
1371 * @jls 8.1.1 Class Modifiers
1372 * @jls 9.1.1 Interface Modifiers
1373 * @jvms 4.1 The {@code ClassFile} Structure
1374 */
1375 public int getModifiers() { return modifiers; }
1376
1377 /**
1378 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1379 * flags} for this class, possibly empty}
1380 *
1381 * <p> If the underlying class is an array class:
1382 * <ul>
1383 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1384 * access flags are the same as those of its component type
1385 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1386 * <li> its {@code INTERFACE} flag is absent, even when the
1387 * component type is an interface
1388 * </ul>
1389 * If this {@code Class} object represents a primitive type or
1390 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1391 * {@code FINAL}.
1392 * For {@code Class} objects representing void, primitive types, and
1393 * arrays, access flags are absent other than as specified above.
1394 *
1395 * @see #getModifiers()
1396 * @jvms 4.1 The ClassFile Structure
1397 * @jvms 4.7.6 The InnerClasses Attribute
1398 * @since 20
1399 */
1400 public Set<AccessFlag> accessFlags() {
1401 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1402 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1403 // and STATIC, which are not allowed on Location.CLASS.
1404 // Use getClassAccessFlagsRaw to expose SUPER status.
1405 var location = (isMemberClass() || isLocalClass() ||
1406 isAnonymousClass() || isArray()) ?
1407 AccessFlag.Location.INNER_CLASS :
1408 AccessFlag.Location.CLASS;
1409 return getReflectionFactory().parseAccessFlags((location == AccessFlag.Location.CLASS) ?
1410 getClassAccessFlagsRaw() : getModifiers(), location, this);
1411 }
1412
1413 /**
1414 * Gets the signers of this class.
1415 *
1416 * @return the signers of this class, or null if there are no signers. In
1417 * particular, this method returns null if this {@code Class} object represents
1418 * a primitive type or void.
1419 * @since 1.1
1420 */
1421 public Object[] getSigners() {
1422 var signers = this.signers;
1423 return signers == null ? null : signers.clone();
1424 }
1425
1426 /**
1427 * Set the signers of this class.
1428 */
1429 void setSigners(Object[] signers) {
1430 if (!isPrimitive() && !isArray()) {
1431 this.signers = signers;
1432 }
1433 }
1434
1435 /**
1436 * If this {@code Class} object represents a local or anonymous
1437 * class within a method, returns a {@link
1438 * java.lang.reflect.Method Method} object representing the
1439 * immediately enclosing method of the underlying class. Returns
1440 * {@code null} otherwise.
1441 *
1442 * In particular, this method returns {@code null} if the underlying
1443 * class is a local or anonymous class immediately enclosed by a class or
1444 * interface declaration, instance initializer or static initializer.
1445 *
1446 * @return the immediately enclosing method of the underlying class, if
1447 * that class is a local or anonymous class; otherwise {@code null}.
1448 *
1449 * @since 1.5
1450 */
1451 public Method getEnclosingMethod() {
1452 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1453
1454 if (enclosingInfo == null)
1455 return null;
1456 else {
1457 if (!enclosingInfo.isMethod())
1458 return null;
1459
1460 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1461 getFactory());
1462 Class<?> returnType = toClass(typeInfo.getReturnType());
1463 Type [] parameterTypes = typeInfo.getParameterTypes();
1464 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1465
1466 // Convert Types to Classes; returned types *should*
1467 // be class objects since the methodDescriptor's used
1468 // don't have generics information
1469 for(int i = 0; i < parameterClasses.length; i++)
1470 parameterClasses[i] = toClass(parameterTypes[i]);
1471
1472 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1473 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1474
1475 /*
1476 * Loop over all declared methods; match method name,
1477 * number of and type of parameters, *and* return
1478 * type. Matching return type is also necessary
1479 * because of covariant returns, etc.
1480 */
1481 ReflectionFactory fact = getReflectionFactory();
1482 for (Method m : candidates) {
1483 if (m.getName().equals(enclosingInfo.getName()) &&
1484 arrayContentsEq(parameterClasses,
1485 fact.getExecutableSharedParameterTypes(m))) {
1486 // finally, check return type
1487 if (m.getReturnType().equals(returnType)) {
1488 return fact.copyMethod(m);
1489 }
1490 }
1491 }
1492
1493 throw new InternalError("Enclosing method not found");
1494 }
1495 }
1496
1497 private native Object[] getEnclosingMethod0();
1498
1499 private EnclosingMethodInfo getEnclosingMethodInfo() {
1500 Object[] enclosingInfo = getEnclosingMethod0();
1501 if (enclosingInfo == null)
1502 return null;
1503 else {
1504 return new EnclosingMethodInfo(enclosingInfo);
1505 }
1506 }
1507
1508 private static final class EnclosingMethodInfo {
1509 private final Class<?> enclosingClass;
1510 private final String name;
1511 private final String descriptor;
1512
1513 static void validate(Object[] enclosingInfo) {
1514 if (enclosingInfo.length != 3)
1515 throw new InternalError("Malformed enclosing method information");
1516 try {
1517 // The array is expected to have three elements:
1518
1519 // the immediately enclosing class
1520 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1521 assert(enclosingClass != null);
1522
1523 // the immediately enclosing method or constructor's
1524 // name (can be null).
1525 String name = (String)enclosingInfo[1];
1526
1527 // the immediately enclosing method or constructor's
1528 // descriptor (null iff name is).
1529 String descriptor = (String)enclosingInfo[2];
1530 assert((name != null && descriptor != null) || name == descriptor);
1531 } catch (ClassCastException cce) {
1532 throw new InternalError("Invalid type in enclosing method information", cce);
1533 }
1534 }
1535
1536 EnclosingMethodInfo(Object[] enclosingInfo) {
1537 validate(enclosingInfo);
1538 this.enclosingClass = (Class<?>)enclosingInfo[0];
1539 this.name = (String)enclosingInfo[1];
1540 this.descriptor = (String)enclosingInfo[2];
1541 }
1542
1543 boolean isPartial() {
1544 return enclosingClass == null || name == null || descriptor == null;
1545 }
1546
1547 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1548
1549 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1550
1551 Class<?> getEnclosingClass() { return enclosingClass; }
1552
1553 String getName() { return name; }
1554
1555 String getDescriptor() { return descriptor; }
1556
1557 }
1558
1559 private static Class<?> toClass(Type o) {
1560 if (o instanceof GenericArrayType gat)
1561 return toClass(gat.getGenericComponentType()).arrayType();
1562 return (Class<?>)o;
1563 }
1564
1565 /**
1566 * If this {@code Class} object represents a local or anonymous
1567 * class within a constructor, returns a {@link
1568 * java.lang.reflect.Constructor Constructor} object representing
1569 * the immediately enclosing constructor of the underlying
1570 * class. Returns {@code null} otherwise. In particular, this
1571 * method returns {@code null} if the underlying class is a local
1572 * or anonymous class immediately enclosed by a class or
1573 * interface declaration, instance initializer or static initializer.
1574 *
1575 * @return the immediately enclosing constructor of the underlying class, if
1576 * that class is a local or anonymous class; otherwise {@code null}.
1577 *
1578 * @since 1.5
1579 */
1580 public Constructor<?> getEnclosingConstructor() {
1581 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1582
1583 if (enclosingInfo == null)
1584 return null;
1585 else {
1586 if (!enclosingInfo.isConstructor())
1587 return null;
1588
1589 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1590 getFactory());
1591 Type [] parameterTypes = typeInfo.getParameterTypes();
1592 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1593
1594 // Convert Types to Classes; returned types *should*
1595 // be class objects since the methodDescriptor's used
1596 // don't have generics information
1597 for (int i = 0; i < parameterClasses.length; i++)
1598 parameterClasses[i] = toClass(parameterTypes[i]);
1599
1600
1601 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1602 Constructor<?>[] candidates = enclosingCandidate
1603 .privateGetDeclaredConstructors(false);
1604 /*
1605 * Loop over all declared constructors; match number
1606 * of and type of parameters.
1607 */
1608 ReflectionFactory fact = getReflectionFactory();
1609 for (Constructor<?> c : candidates) {
1610 if (arrayContentsEq(parameterClasses,
1611 fact.getExecutableSharedParameterTypes(c))) {
1612 return fact.copyConstructor(c);
1613 }
1614 }
1615
1616 throw new InternalError("Enclosing constructor not found");
1617 }
1618 }
1619
1620
1621 /**
1622 * If the class or interface represented by this {@code Class} object
1623 * is a member of another class, returns the {@code Class} object
1624 * representing the class in which it was declared. This method returns
1625 * null if this class or interface is not a member of any other class. If
1626 * this {@code Class} object represents an array class, a primitive
1627 * type, or void, then this method returns null.
1628 *
1629 * @return the declaring class for this class
1630 * @since 1.1
1631 */
1632 public Class<?> getDeclaringClass() {
1633 return getDeclaringClass0();
1634 }
1635
1636 private native Class<?> getDeclaringClass0();
1637
1638
1639 /**
1640 * Returns the immediately enclosing class of the underlying
1641 * class. If the underlying class is a top level class this
1642 * method returns {@code null}.
1643 * @return the immediately enclosing class of the underlying class
1644 * @since 1.5
1645 */
1646 public Class<?> getEnclosingClass() {
1647 // There are five kinds of classes (or interfaces):
1648 // a) Top level classes
1649 // b) Nested classes (static member classes)
1650 // c) Inner classes (non-static member classes)
1651 // d) Local classes (named classes declared within a method)
1652 // e) Anonymous classes
1653
1654
1655 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1656 // attribute if and only if it is a local class or an
1657 // anonymous class.
1658 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1659 Class<?> enclosingCandidate;
1660
1661 if (enclosingInfo == null) {
1662 // This is a top level or a nested class or an inner class (a, b, or c)
1663 enclosingCandidate = getDeclaringClass0();
1664 } else {
1665 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1666 // This is a local class or an anonymous class (d or e)
1667 if (enclosingClass == this || enclosingClass == null)
1668 throw new InternalError("Malformed enclosing method information");
1669 else
1670 enclosingCandidate = enclosingClass;
1671 }
1672 return enclosingCandidate;
1673 }
1674
1675 /**
1676 * Returns the simple name of the underlying class as given in the
1677 * source code. An empty string is returned if the underlying class is
1678 * {@linkplain #isAnonymousClass() anonymous}.
1679 * A {@linkplain #isSynthetic() synthetic class}, one not present
1680 * in source code, can have a non-empty name including special
1681 * characters, such as "{@code $}".
1682 *
1683 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1684 * component type with "[]" appended. In particular the simple
1685 * name of an array class whose component type is anonymous is "[]".
1686 *
1687 * @return the simple name of the underlying class
1688 * @since 1.5
1689 */
1690 public String getSimpleName() {
1691 ReflectionData<T> rd = reflectionData();
1692 String simpleName = rd.simpleName;
1693 if (simpleName == null) {
1694 rd.simpleName = simpleName = getSimpleName0();
1695 }
1696 return simpleName;
1697 }
1698
1699 private String getSimpleName0() {
1700 if (isArray()) {
1701 return getComponentType().getSimpleName().concat("[]");
1702 }
1703 String simpleName = getSimpleBinaryName();
1704 if (simpleName == null) { // top level class
1705 simpleName = getName();
1706 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1707 }
1708 return simpleName;
1709 }
1710
1711 /**
1712 * Return an informative string for the name of this class or interface.
1713 *
1714 * @return an informative string for the name of this class or interface
1715 * @since 1.8
1716 */
1717 public String getTypeName() {
1718 if (isArray()) {
1719 try {
1720 Class<?> cl = this;
1721 int dimensions = 0;
1722 do {
1723 dimensions++;
1724 cl = cl.getComponentType();
1725 } while (cl.isArray());
1726 return cl.getName().concat("[]".repeat(dimensions));
1727 } catch (Throwable e) { /*FALLTHRU*/ }
1728 }
1729 return getName();
1730 }
1731
1732 /**
1733 * Returns the canonical name of the underlying class as
1734 * defined by <cite>The Java Language Specification</cite>.
1735 * Returns {@code null} if the underlying class does not have a canonical
1736 * name. Classes without canonical names include:
1737 * <ul>
1738 * <li>a {@linkplain #isLocalClass() local class}
1739 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1740 * <li>a {@linkplain #isHidden() hidden class}
1741 * <li>an array whose component type does not have a canonical name</li>
1742 * </ul>
1743 *
1744 * The canonical name for a primitive class is the keyword for the
1745 * corresponding primitive type ({@code byte}, {@code short},
1746 * {@code char}, {@code int}, and so on).
1747 *
1748 * <p>An array type has a canonical name if and only if its
1749 * component type has a canonical name. When an array type has a
1750 * canonical name, it is equal to the canonical name of the
1751 * component type followed by "{@code []}".
1752 *
1753 * @return the canonical name of the underlying class if it exists, and
1754 * {@code null} otherwise.
1755 * @jls 6.7 Fully Qualified Names and Canonical Names
1756 * @since 1.5
1757 */
1758 public String getCanonicalName() {
1759 ReflectionData<T> rd = reflectionData();
1760 String canonicalName = rd.canonicalName;
1761 if (canonicalName == null) {
1762 rd.canonicalName = canonicalName = getCanonicalName0();
1763 }
1764 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1765 }
1766
1767 private String getCanonicalName0() {
1768 if (isArray()) {
1769 String canonicalName = getComponentType().getCanonicalName();
1770 if (canonicalName != null)
1771 return canonicalName.concat("[]");
1772 else
1773 return ReflectionData.NULL_SENTINEL;
1774 }
1775 if (isHidden() || isLocalOrAnonymousClass())
1776 return ReflectionData.NULL_SENTINEL;
1777 Class<?> enclosingClass = getEnclosingClass();
1778 if (enclosingClass == null) { // top level class
1779 return getName();
1780 } else {
1781 String enclosingName = enclosingClass.getCanonicalName();
1782 if (enclosingName == null)
1783 return ReflectionData.NULL_SENTINEL;
1784 String simpleName = getSimpleName();
1785 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1786 .append(enclosingName)
1787 .append('.')
1788 .append(simpleName)
1789 .toString();
1790 }
1791 }
1792
1793 /**
1794 * Returns {@code true} if and only if the underlying class
1795 * is an anonymous class.
1796 *
1797 * @apiNote
1798 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1799 *
1800 * @return {@code true} if and only if this class is an anonymous class.
1801 * @since 1.5
1802 * @jls 15.9.5 Anonymous Class Declarations
1803 */
1804 public boolean isAnonymousClass() {
1805 return !isArray() && isLocalOrAnonymousClass() &&
1806 getSimpleBinaryName0() == null;
1807 }
1808
1809 /**
1810 * Returns {@code true} if and only if the underlying class
1811 * is a local class.
1812 *
1813 * @return {@code true} if and only if this class is a local class.
1814 * @since 1.5
1815 * @jls 14.3 Local Class and Interface Declarations
1816 */
1817 public boolean isLocalClass() {
1818 return isLocalOrAnonymousClass() &&
1819 (isArray() || getSimpleBinaryName0() != null);
1820 }
1821
1822 /**
1823 * Returns {@code true} if and only if the underlying class
1824 * is a member class.
1825 *
1826 * @return {@code true} if and only if this class is a member class.
1827 * @since 1.5
1828 * @jls 8.5 Member Class and Interface Declarations
1829 */
1830 public boolean isMemberClass() {
1831 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1832 }
1833
1834 /**
1835 * Returns the "simple binary name" of the underlying class, i.e.,
1836 * the binary name without the leading enclosing class name.
1837 * Returns {@code null} if the underlying class is a top level
1838 * class.
1839 */
1840 private String getSimpleBinaryName() {
1841 if (isTopLevelClass())
1842 return null;
1843 String name = getSimpleBinaryName0();
1844 if (name == null) // anonymous class
1845 return "";
1846 return name;
1847 }
1848
1849 private native String getSimpleBinaryName0();
1850
1851 /**
1852 * Returns {@code true} if this is a top level class. Returns {@code false}
1853 * otherwise.
1854 */
1855 private boolean isTopLevelClass() {
1856 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1857 }
1858
1859 /**
1860 * Returns {@code true} if this is a local class or an anonymous
1861 * class. Returns {@code false} otherwise.
1862 */
1863 private boolean isLocalOrAnonymousClass() {
1864 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1865 // attribute if and only if it is a local class or an
1866 // anonymous class.
1867 return hasEnclosingMethodInfo();
1868 }
1869
1870 private boolean hasEnclosingMethodInfo() {
1871 Object[] enclosingInfo = getEnclosingMethod0();
1872 if (enclosingInfo != null) {
1873 EnclosingMethodInfo.validate(enclosingInfo);
1874 return true;
1875 }
1876 return false;
1877 }
1878
1879 /**
1880 * Returns an array containing {@code Class} objects representing all
1881 * the public classes and interfaces that are members of the class
1882 * represented by this {@code Class} object. This includes public
1883 * class and interface members inherited from superclasses and public class
1884 * and interface members declared by the class. This method returns an
1885 * array of length 0 if this {@code Class} object has no public member
1886 * classes or interfaces. This method also returns an array of length 0 if
1887 * this {@code Class} object represents a primitive type, an array
1888 * class, or void.
1889 *
1890 * @return the array of {@code Class} objects representing the public
1891 * members of this class
1892 * @since 1.1
1893 */
1894 public Class<?>[] getClasses() {
1895 List<Class<?>> list = new ArrayList<>();
1896 Class<?> currentClass = Class.this;
1897 while (currentClass != null) {
1898 for (Class<?> m : currentClass.getDeclaredClasses()) {
1899 if (Modifier.isPublic(m.getModifiers())) {
1900 list.add(m);
1901 }
1902 }
1903 currentClass = currentClass.getSuperclass();
1904 }
1905 return list.toArray(new Class<?>[0]);
1906 }
1907
1908
1909 /**
1910 * Returns an array containing {@code Field} objects reflecting all
1911 * the accessible public fields of the class or interface represented by
1912 * this {@code Class} object.
1913 *
1914 * <p> If this {@code Class} object represents a class or interface with
1915 * no accessible public fields, then this method returns an array of length
1916 * 0.
1917 *
1918 * <p> If this {@code Class} object represents a class, then this method
1919 * returns the public fields of the class and of all its superclasses and
1920 * superinterfaces.
1921 *
1922 * <p> If this {@code Class} object represents an interface, then this
1923 * method returns the fields of the interface and of all its
1924 * superinterfaces.
1925 *
1926 * <p> If this {@code Class} object represents an array type, a primitive
1927 * type, or void, then this method returns an array of length 0.
1928 *
1929 * <p> The elements in the returned array are not sorted and are not in any
1930 * particular order.
1931 *
1932 * @return the array of {@code Field} objects representing the
1933 * public fields
1934 *
1935 * @since 1.1
1936 * @jls 8.2 Class Members
1937 * @jls 8.3 Field Declarations
1938 */
1939 public Field[] getFields() {
1940 return copyFields(privateGetPublicFields());
1941 }
1942
1943
1944 /**
1945 * Returns an array containing {@code Method} objects reflecting all the
1946 * public methods of the class or interface represented by this {@code
1947 * Class} object, including those declared by the class or interface and
1948 * those inherited from superclasses and superinterfaces.
1949 *
1950 * <p> If this {@code Class} object represents an array type, then the
1951 * returned array has a {@code Method} object for each of the public
1952 * methods inherited by the array type from {@code Object}. It does not
1953 * contain a {@code Method} object for {@code clone()}.
1954 *
1955 * <p> If this {@code Class} object represents an interface then the
1956 * returned array does not contain any implicitly declared methods from
1957 * {@code Object}. Therefore, if no methods are explicitly declared in
1958 * this interface or any of its superinterfaces then the returned array
1959 * has length 0. (Note that a {@code Class} object which represents a class
1960 * always has public methods, inherited from {@code Object}.)
1961 *
1962 * <p> The returned array never contains methods with names {@value
1963 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1964 *
1965 * <p> The elements in the returned array are not sorted and are not in any
1966 * particular order.
1967 *
1968 * <p> Generally, the result is computed as with the following 4 step algorithm.
1969 * Let C be the class or interface represented by this {@code Class} object:
1970 * <ol>
1971 * <li> A union of methods is composed of:
1972 * <ol type="a">
1973 * <li> C's declared public instance and static methods as returned by
1974 * {@link #getDeclaredMethods()} and filtered to include only public
1975 * methods.</li>
1976 * <li> If C is a class other than {@code Object}, then include the result
1977 * of invoking this algorithm recursively on the superclass of C.</li>
1978 * <li> Include the results of invoking this algorithm recursively on all
1979 * direct superinterfaces of C, but include only instance methods.</li>
1980 * </ol></li>
1981 * <li> Union from step 1 is partitioned into subsets of methods with same
1982 * signature (name, parameter types) and return type.</li>
1983 * <li> Within each such subset only the most specific methods are selected.
1984 * Let method M be a method from a set of methods with same signature
1985 * and return type. M is most specific if there is no such method
1986 * N != M from the same set, such that N is more specific than M.
1987 * N is more specific than M if:
1988 * <ol type="a">
1989 * <li> N is declared by a class and M is declared by an interface; or</li>
1990 * <li> N and M are both declared by classes or both by interfaces and
1991 * N's declaring type is the same as or a subtype of M's declaring type
1992 * (clearly, if M's and N's declaring types are the same type, then
1993 * M and N are the same method).</li>
1994 * </ol></li>
1995 * <li> The result of this algorithm is the union of all selected methods from
1996 * step 3.</li>
1997 * </ol>
1998 *
1999 * @apiNote There may be more than one method with a particular name
2000 * and parameter types in a class because while the Java language forbids a
2001 * class to declare multiple methods with the same signature but different
2002 * return types, the Java virtual machine does not. This
2003 * increased flexibility in the virtual machine can be used to
2004 * implement various language features. For example, covariant
2005 * returns can be implemented with {@linkplain
2006 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2007 * method and the overriding method would have the same
2008 * signature but different return types.
2009 *
2010 * @return the array of {@code Method} objects representing the
2011 * public methods of this class
2012 *
2013 * @jls 8.2 Class Members
2014 * @jls 8.4 Method Declarations
2015 * @since 1.1
2016 */
2017 public Method[] getMethods() {
2018 return copyMethods(privateGetPublicMethods());
2019 }
2020
2021
2022 /**
2023 * Returns an array containing {@code Constructor} objects reflecting
2024 * all the public constructors of the class represented by this
2025 * {@code Class} object. An array of length 0 is returned if the
2026 * class has no public constructors, or if the class is an array class, or
2027 * if the class reflects a primitive type or void.
2028 *
2029 * @apiNote
2030 * While this method returns an array of {@code
2031 * Constructor<T>} objects (that is an array of constructors from
2032 * this class), the return type of this method is {@code
2033 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2034 * might be expected. This less informative return type is
2035 * necessary since after being returned from this method, the
2036 * array could be modified to hold {@code Constructor} objects for
2037 * different classes, which would violate the type guarantees of
2038 * {@code Constructor<T>[]}.
2039 *
2040 * @return the array of {@code Constructor} objects representing the
2041 * public constructors of this class
2042 *
2043 * @see #getDeclaredConstructors()
2044 * @since 1.1
2045 */
2046 public Constructor<?>[] getConstructors() {
2047 return copyConstructors(privateGetDeclaredConstructors(true));
2048 }
2049
2050
2051 /**
2052 * Returns a {@code Field} object that reflects the specified public member
2053 * field of the class or interface represented by this {@code Class}
2054 * object. The {@code name} parameter is a {@code String} specifying the
2055 * simple name of the desired field.
2056 *
2057 * <p> The field to be reflected is determined by the algorithm that
2058 * follows. Let C be the class or interface represented by this {@code Class} object:
2059 *
2060 * <OL>
2061 * <LI> If C declares a public field with the name specified, that is the
2062 * field to be reflected.</LI>
2063 * <LI> If no field was found in step 1 above, this algorithm is applied
2064 * recursively to each direct superinterface of C. The direct
2065 * superinterfaces are searched in the order they were declared.</LI>
2066 * <LI> If no field was found in steps 1 and 2 above, and C has a
2067 * superclass S, then this algorithm is invoked recursively upon S.
2068 * If C has no superclass, then a {@code NoSuchFieldException}
2069 * is thrown.</LI>
2070 * </OL>
2071 *
2072 * <p> If this {@code Class} object represents an array type, then this
2073 * method does not find the {@code length} field of the array type.
2074 *
2075 * @param name the field name
2076 * @return the {@code Field} object of this class specified by
2077 * {@code name}
2078 * @throws NoSuchFieldException if a field with the specified name is
2079 * not found.
2080 * @throws NullPointerException if {@code name} is {@code null}
2081 *
2082 * @since 1.1
2083 * @jls 8.2 Class Members
2084 * @jls 8.3 Field Declarations
2085 */
2086 public Field getField(String name) throws NoSuchFieldException {
2087 Objects.requireNonNull(name);
2088 Field field = getField0(name);
2089 if (field == null) {
2090 throw new NoSuchFieldException(name);
2091 }
2092 return getReflectionFactory().copyField(field);
2093 }
2094
2095
2096 /**
2097 * Returns a {@code Method} object that reflects the specified public
2098 * member method of the class or interface represented by this
2099 * {@code Class} object. The {@code name} parameter is a
2100 * {@code String} specifying the simple name of the desired method. The
2101 * {@code parameterTypes} parameter is an array of {@code Class}
2102 * objects that identify the method's formal parameter types, in declared
2103 * order. If {@code parameterTypes} is {@code null}, it is
2104 * treated as if it were an empty array.
2105 *
2106 * <p> If this {@code Class} object represents an array type, then this
2107 * method finds any public method inherited by the array type from
2108 * {@code Object} except method {@code clone()}.
2109 *
2110 * <p> If this {@code Class} object represents an interface then this
2111 * method does not find any implicitly declared method from
2112 * {@code Object}. Therefore, if no methods are explicitly declared in
2113 * this interface or any of its superinterfaces, then this method does not
2114 * find any method.
2115 *
2116 * <p> This method does not find any method with name {@value
2117 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2118 *
2119 * <p> Generally, the method to be reflected is determined by the 4 step
2120 * algorithm that follows.
2121 * Let C be the class or interface represented by this {@code Class} object:
2122 * <ol>
2123 * <li> A union of methods is composed of:
2124 * <ol type="a">
2125 * <li> C's declared public instance and static methods as returned by
2126 * {@link #getDeclaredMethods()} and filtered to include only public
2127 * methods that match given {@code name} and {@code parameterTypes}</li>
2128 * <li> If C is a class other than {@code Object}, then include the result
2129 * of invoking this algorithm recursively on the superclass of C.</li>
2130 * <li> Include the results of invoking this algorithm recursively on all
2131 * direct superinterfaces of C, but include only instance methods.</li>
2132 * </ol></li>
2133 * <li> This union is partitioned into subsets of methods with same
2134 * return type (the selection of methods from step 1 also guarantees that
2135 * they have the same method name and parameter types).</li>
2136 * <li> Within each such subset only the most specific methods are selected.
2137 * Let method M be a method from a set of methods with same VM
2138 * signature (return type, name, parameter types).
2139 * M is most specific if there is no such method N != M from the same
2140 * set, such that N is more specific than M. N is more specific than M
2141 * if:
2142 * <ol type="a">
2143 * <li> N is declared by a class and M is declared by an interface; or</li>
2144 * <li> N and M are both declared by classes or both by interfaces and
2145 * N's declaring type is the same as or a subtype of M's declaring type
2146 * (clearly, if M's and N's declaring types are the same type, then
2147 * M and N are the same method).</li>
2148 * </ol></li>
2149 * <li> The result of this algorithm is chosen arbitrarily from the methods
2150 * with most specific return type among all selected methods from step 3.
2151 * Let R be a return type of a method M from the set of all selected methods
2152 * from step 3. M is a method with most specific return type if there is
2153 * no such method N != M from the same set, having return type S != R,
2154 * such that S is a subtype of R as determined by
2155 * R.class.{@link #isAssignableFrom}(S.class).
2156 * </ol>
2157 *
2158 * @apiNote There may be more than one method with matching name and
2159 * parameter types in a class because while the Java language forbids a
2160 * class to declare multiple methods with the same signature but different
2161 * return types, the Java virtual machine does not. This
2162 * increased flexibility in the virtual machine can be used to
2163 * implement various language features. For example, covariant
2164 * returns can be implemented with {@linkplain
2165 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2166 * method and the overriding method would have the same
2167 * signature but different return types. This method would return the
2168 * overriding method as it would have a more specific return type.
2169 *
2170 * @param name the name of the method
2171 * @param parameterTypes the list of parameters
2172 * @return the {@code Method} object that matches the specified
2173 * {@code name} and {@code parameterTypes}
2174 * @throws NoSuchMethodException if a matching method is not found
2175 * or if the name is {@value ConstantDescs#INIT_NAME} or
2176 * {@value ConstantDescs#CLASS_INIT_NAME}.
2177 * @throws NullPointerException if {@code name} is {@code null}
2178 *
2179 * @jls 8.2 Class Members
2180 * @jls 8.4 Method Declarations
2181 * @since 1.1
2182 */
2183 public Method getMethod(String name, Class<?>... parameterTypes)
2184 throws NoSuchMethodException {
2185 Objects.requireNonNull(name);
2186 Method method = getMethod0(name, parameterTypes);
2187 if (method == null) {
2188 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2189 }
2190 return getReflectionFactory().copyMethod(method);
2191 }
2192
2193 /**
2194 * Returns a {@code Constructor} object that reflects the specified
2195 * public constructor of the class represented by this {@code Class}
2196 * object. The {@code parameterTypes} parameter is an array of
2197 * {@code Class} objects that identify the constructor's formal
2198 * parameter types, in declared order.
2199 *
2200 * If this {@code Class} object represents an inner class
2201 * declared in a non-static context, the formal parameter types
2202 * include the explicit enclosing instance as the first parameter.
2203 *
2204 * <p> The constructor to reflect is the public constructor of the class
2205 * represented by this {@code Class} object whose formal parameter
2206 * types match those specified by {@code parameterTypes}.
2207 *
2208 * @param parameterTypes the parameter array
2209 * @return the {@code Constructor} object of the public constructor that
2210 * matches the specified {@code parameterTypes}
2211 * @throws NoSuchMethodException if a matching constructor is not found,
2212 * including when this {@code Class} object represents
2213 * an interface, a primitive type, an array class, or void.
2214 *
2215 * @see #getDeclaredConstructor(Class[])
2216 * @since 1.1
2217 */
2218 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2219 throws NoSuchMethodException {
2220 return getReflectionFactory().copyConstructor(
2221 getConstructor0(parameterTypes, Member.PUBLIC));
2222 }
2223
2224
2225 /**
2226 * Returns an array of {@code Class} objects reflecting all the
2227 * classes and interfaces declared as members of the class represented by
2228 * this {@code Class} object. This includes public, protected, default
2229 * (package) access, and private classes and interfaces declared by the
2230 * class, but excludes inherited classes and interfaces. This method
2231 * returns an array of length 0 if the class declares no classes or
2232 * interfaces as members, or if this {@code Class} object represents a
2233 * primitive type, an array class, or void.
2234 *
2235 * @return the array of {@code Class} objects representing all the
2236 * declared members of this class
2237 *
2238 * @since 1.1
2239 * @jls 8.5 Member Class and Interface Declarations
2240 */
2241 public Class<?>[] getDeclaredClasses() {
2242 return getDeclaredClasses0();
2243 }
2244
2245
2246 /**
2247 * Returns an array of {@code Field} objects reflecting all the fields
2248 * declared by the class or interface represented by this
2249 * {@code Class} object. This includes public, protected, default
2250 * (package) access, and private fields, but excludes inherited fields.
2251 *
2252 * <p> If this {@code Class} object represents a class or interface with no
2253 * declared fields, then this method returns an array of length 0.
2254 *
2255 * <p> If this {@code Class} object represents an array type, a primitive
2256 * type, or void, then this method returns an array of length 0.
2257 *
2258 * <p> The elements in the returned array are not sorted and are not in any
2259 * particular order.
2260 *
2261 * @return the array of {@code Field} objects representing all the
2262 * declared fields of this class
2263 *
2264 * @since 1.1
2265 * @jls 8.2 Class Members
2266 * @jls 8.3 Field Declarations
2267 */
2268 public Field[] getDeclaredFields() {
2269 return copyFields(privateGetDeclaredFields(false));
2270 }
2271
2272 /**
2273 * Returns an array of {@code RecordComponent} objects representing all the
2274 * record components of this record class, or {@code null} if this class is
2275 * not a record class.
2276 *
2277 * <p> The components are returned in the same order that they are declared
2278 * in the record header. The array is empty if this record class has no
2279 * components. If the class is not a record class, that is {@link
2280 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2281 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2282 * returns a non-null value.
2283 *
2284 * @apiNote
2285 * <p> The following method can be used to find the record canonical constructor:
2286 *
2287 * {@snippet lang="java" :
2288 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2289 * throws NoSuchMethodException {
2290 * Class<?>[] paramTypes =
2291 * Arrays.stream(cls.getRecordComponents())
2292 * .map(RecordComponent::getType)
2293 * .toArray(Class<?>[]::new);
2294 * return cls.getDeclaredConstructor(paramTypes);
2295 * }}
2296 *
2297 * @return An array of {@code RecordComponent} objects representing all the
2298 * record components of this record class, or {@code null} if this
2299 * class is not a record class
2300 *
2301 * @jls 8.10 Record Classes
2302 * @since 16
2303 */
2304 public RecordComponent[] getRecordComponents() {
2305 if (!isRecord()) {
2306 return null;
2307 }
2308 return getRecordComponents0();
2309 }
2310
2311 /**
2312 * Returns an array containing {@code Method} objects reflecting all the
2313 * declared methods of the class or interface represented by this {@code
2314 * Class} object, including public, protected, default (package)
2315 * access, and private methods, but excluding inherited methods.
2316 * The declared methods may include methods <em>not</em> in the
2317 * source of the class or interface, including {@linkplain
2318 * Method#isBridge bridge methods} and other {@linkplain
2319 * Executable#isSynthetic synthetic} methods added by compilers.
2320 *
2321 * <p> If this {@code Class} object represents a class or interface that
2322 * has multiple declared methods with the same name and parameter types,
2323 * but different return types, then the returned array has a {@code Method}
2324 * object for each such method.
2325 *
2326 * <p> If this {@code Class} object represents a class or interface that
2327 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2328 * then the returned array does <em>not</em> have a corresponding {@code
2329 * Method} object.
2330 *
2331 * <p> If this {@code Class} object represents a class or interface with no
2332 * declared methods, then the returned array has length 0.
2333 *
2334 * <p> If this {@code Class} object represents an array type, a primitive
2335 * type, or void, then the returned array has length 0.
2336 *
2337 * <p> The elements in the returned array are not sorted and are not in any
2338 * particular order.
2339 *
2340 * @return the array of {@code Method} objects representing all the
2341 * declared methods of this class
2342 *
2343 * @jls 8.2 Class Members
2344 * @jls 8.4 Method Declarations
2345 * @see <a
2346 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2347 * programming language and JVM modeling in core reflection</a>
2348 * @since 1.1
2349 */
2350 public Method[] getDeclaredMethods() {
2351 return copyMethods(privateGetDeclaredMethods(false));
2352 }
2353
2354 /**
2355 * Returns an array of {@code Constructor} objects reflecting all the
2356 * constructors implicitly or explicitly declared by the class represented by this
2357 * {@code Class} object. These are public, protected, default
2358 * (package) access, and private constructors. The elements in the array
2359 * returned are not sorted and are not in any particular order. If the
2360 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2361 * If a record class has a canonical constructor (JLS {@jls
2362 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2363 *
2364 * This method returns an array of length 0 if this {@code Class}
2365 * object represents an interface, a primitive type, an array class, or
2366 * void.
2367 *
2368 * @return the array of {@code Constructor} objects representing all the
2369 * declared constructors of this class
2370 *
2371 * @since 1.1
2372 * @see #getConstructors()
2373 * @jls 8.8 Constructor Declarations
2374 */
2375 public Constructor<?>[] getDeclaredConstructors() {
2376 return copyConstructors(privateGetDeclaredConstructors(false));
2377 }
2378
2379
2380 /**
2381 * Returns a {@code Field} object that reflects the specified declared
2382 * field of the class or interface represented by this {@code Class}
2383 * object. The {@code name} parameter is a {@code String} that specifies
2384 * the simple name of the desired field.
2385 *
2386 * <p> If this {@code Class} object represents an array type, then this
2387 * method does not find the {@code length} field of the array type.
2388 *
2389 * @param name the name of the field
2390 * @return the {@code Field} object for the specified field in this
2391 * class
2392 * @throws NoSuchFieldException if a field with the specified name is
2393 * not found.
2394 * @throws NullPointerException if {@code name} is {@code null}
2395 *
2396 * @since 1.1
2397 * @jls 8.2 Class Members
2398 * @jls 8.3 Field Declarations
2399 */
2400 public Field getDeclaredField(String name) throws NoSuchFieldException {
2401 Objects.requireNonNull(name);
2402 Field field = searchFields(privateGetDeclaredFields(false), name);
2403 if (field == null) {
2404 throw new NoSuchFieldException(name);
2405 }
2406 return getReflectionFactory().copyField(field);
2407 }
2408
2409
2410 /**
2411 * Returns a {@code Method} object that reflects the specified
2412 * declared method of the class or interface represented by this
2413 * {@code Class} object. The {@code name} parameter is a
2414 * {@code String} that specifies the simple name of the desired
2415 * method, and the {@code parameterTypes} parameter is an array of
2416 * {@code Class} objects that identify the method's formal parameter
2417 * types, in declared order. If more than one method with the same
2418 * parameter types is declared in a class, and one of these methods has a
2419 * return type that is more specific than any of the others, that method is
2420 * returned; otherwise one of the methods is chosen arbitrarily. If the
2421 * name is {@value ConstantDescs#INIT_NAME} or {@value
2422 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2423 * is raised.
2424 *
2425 * <p> If this {@code Class} object represents an array type, then this
2426 * method does not find the {@code clone()} method.
2427 *
2428 * @param name the name of the method
2429 * @param parameterTypes the parameter array
2430 * @return the {@code Method} object for the method of this class
2431 * matching the specified name and parameters
2432 * @throws NoSuchMethodException if a matching method is not found.
2433 * @throws NullPointerException if {@code name} is {@code null}
2434 *
2435 * @jls 8.2 Class Members
2436 * @jls 8.4 Method Declarations
2437 * @since 1.1
2438 */
2439 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2440 throws NoSuchMethodException {
2441 Objects.requireNonNull(name);
2442 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2443 if (method == null) {
2444 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2445 }
2446 return getReflectionFactory().copyMethod(method);
2447 }
2448
2449 /**
2450 * Returns the list of {@code Method} objects for the declared public
2451 * methods of this class or interface that have the specified method name
2452 * and parameter types.
2453 *
2454 * @param name the name of the method
2455 * @param parameterTypes the parameter array
2456 * @return the list of {@code Method} objects for the public methods of
2457 * this class matching the specified name and parameters
2458 */
2459 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2460 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2461 ReflectionFactory factory = getReflectionFactory();
2462 List<Method> result = new ArrayList<>();
2463 for (Method method : methods) {
2464 if (method.getName().equals(name)
2465 && Arrays.equals(
2466 factory.getExecutableSharedParameterTypes(method),
2467 parameterTypes)) {
2468 result.add(factory.copyMethod(method));
2469 }
2470 }
2471 return result;
2472 }
2473
2474 /**
2475 * Returns the most specific {@code Method} object of this class, super class or
2476 * interface that have the specified method name and parameter types.
2477 *
2478 * @param publicOnly true if only public methods are examined, otherwise all methods
2479 * @param name the name of the method
2480 * @param parameterTypes the parameter array
2481 * @return the {@code Method} object for the method found from this class matching
2482 * the specified name and parameters, or null if not found
2483 */
2484 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2485 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2486 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2487 }
2488
2489 /**
2490 * Returns a {@code Constructor} object that reflects the specified
2491 * constructor of the class represented by this
2492 * {@code Class} object. The {@code parameterTypes} parameter is
2493 * an array of {@code Class} objects that identify the constructor's
2494 * formal parameter types, in declared order.
2495 *
2496 * If this {@code Class} object represents an inner class
2497 * declared in a non-static context, the formal parameter types
2498 * include the explicit enclosing instance as the first parameter.
2499 *
2500 * @param parameterTypes the parameter array
2501 * @return The {@code Constructor} object for the constructor with the
2502 * specified parameter list
2503 * @throws NoSuchMethodException if a matching constructor is not found,
2504 * including when this {@code Class} object represents
2505 * an interface, a primitive type, an array class, or void.
2506 *
2507 * @see #getConstructor(Class[])
2508 * @since 1.1
2509 */
2510 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2511 throws NoSuchMethodException {
2512 return getReflectionFactory().copyConstructor(
2513 getConstructor0(parameterTypes, Member.DECLARED));
2514 }
2515
2516 /**
2517 * Finds a resource with a given name.
2518 *
2519 * <p> If this class is in a named {@link Module Module} then this method
2520 * will attempt to find the resource in the module. This is done by
2521 * delegating to the module's class loader {@link
2522 * ClassLoader#findResource(String,String) findResource(String,String)}
2523 * method, invoking it with the module name and the absolute name of the
2524 * resource. Resources in named modules are subject to the rules for
2525 * encapsulation specified in the {@code Module} {@link
2526 * Module#getResourceAsStream getResourceAsStream} method and so this
2527 * method returns {@code null} when the resource is a
2528 * non-"{@code .class}" resource in a package that is not open to the
2529 * caller's module.
2530 *
2531 * <p> Otherwise, if this class is not in a named module then the rules for
2532 * searching resources associated with a given class are implemented by the
2533 * defining {@linkplain ClassLoader class loader} of the class. This method
2534 * delegates to this {@code Class} object's class loader.
2535 * If this {@code Class} object was loaded by the bootstrap class loader,
2536 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2537 *
2538 * <p> Before delegation, an absolute resource name is constructed from the
2539 * given resource name using this algorithm:
2540 *
2541 * <ul>
2542 *
2543 * <li> If the {@code name} begins with a {@code '/'}
2544 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2545 * portion of the {@code name} following the {@code '/'}.
2546 *
2547 * <li> Otherwise, the absolute name is of the following form:
2548 *
2549 * <blockquote>
2550 * {@code modified_package_name/name}
2551 * </blockquote>
2552 *
2553 * <p> Where the {@code modified_package_name} is the package name of this
2554 * object with {@code '/'} substituted for {@code '.'}
2555 * (<code>'\u002e'</code>).
2556 *
2557 * </ul>
2558 *
2559 * @param name name of the desired resource
2560 * @return A {@link java.io.InputStream} object; {@code null} if no
2561 * resource with this name is found, or the resource is in a package
2562 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2563 * least the caller module.
2564 * @throws NullPointerException If {@code name} is {@code null}
2565 *
2566 * @see Module#getResourceAsStream(String)
2567 * @since 1.1
2568 */
2569 @CallerSensitive
2570 public InputStream getResourceAsStream(String name) {
2571 name = resolveName(name);
2572
2573 Module thisModule = getModule();
2574 if (thisModule.isNamed()) {
2575 // check if resource can be located by caller
2576 if (Resources.canEncapsulate(name)
2577 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2578 return null;
2579 }
2580
2581 // resource not encapsulated or in package open to caller
2582 String mn = thisModule.getName();
2583 ClassLoader cl = classLoader;
2584 try {
2585
2586 // special-case built-in class loaders to avoid the
2587 // need for a URL connection
2588 if (cl == null) {
2589 return BootLoader.findResourceAsStream(mn, name);
2590 } else if (cl instanceof BuiltinClassLoader bcl) {
2591 return bcl.findResourceAsStream(mn, name);
2592 } else {
2593 URL url = cl.findResource(mn, name);
2594 return (url != null) ? url.openStream() : null;
2595 }
2596
2597 } catch (IOException | SecurityException e) {
2598 return null;
2599 }
2600 }
2601
2602 // unnamed module
2603 ClassLoader cl = classLoader;
2604 if (cl == null) {
2605 return ClassLoader.getSystemResourceAsStream(name);
2606 } else {
2607 return cl.getResourceAsStream(name);
2608 }
2609 }
2610
2611 /**
2612 * Finds a resource with a given name.
2613 *
2614 * <p> If this class is in a named {@link Module Module} then this method
2615 * will attempt to find the resource in the module. This is done by
2616 * delegating to the module's class loader {@link
2617 * ClassLoader#findResource(String,String) findResource(String,String)}
2618 * method, invoking it with the module name and the absolute name of the
2619 * resource. Resources in named modules are subject to the rules for
2620 * encapsulation specified in the {@code Module} {@link
2621 * Module#getResourceAsStream getResourceAsStream} method and so this
2622 * method returns {@code null} when the resource is a
2623 * non-"{@code .class}" resource in a package that is not open to the
2624 * caller's module.
2625 *
2626 * <p> Otherwise, if this class is not in a named module then the rules for
2627 * searching resources associated with a given class are implemented by the
2628 * defining {@linkplain ClassLoader class loader} of the class. This method
2629 * delegates to this {@code Class} object's class loader.
2630 * If this {@code Class} object was loaded by the bootstrap class loader,
2631 * the method delegates to {@link ClassLoader#getSystemResource}.
2632 *
2633 * <p> Before delegation, an absolute resource name is constructed from the
2634 * given resource name using this algorithm:
2635 *
2636 * <ul>
2637 *
2638 * <li> If the {@code name} begins with a {@code '/'}
2639 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2640 * portion of the {@code name} following the {@code '/'}.
2641 *
2642 * <li> Otherwise, the absolute name is of the following form:
2643 *
2644 * <blockquote>
2645 * {@code modified_package_name/name}
2646 * </blockquote>
2647 *
2648 * <p> Where the {@code modified_package_name} is the package name of this
2649 * object with {@code '/'} substituted for {@code '.'}
2650 * (<code>'\u002e'</code>).
2651 *
2652 * </ul>
2653 *
2654 * @param name name of the desired resource
2655 * @return A {@link java.net.URL} object; {@code null} if no resource with
2656 * this name is found, the resource cannot be located by a URL, or the
2657 * resource is in a package that is not
2658 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2659 * module.
2660 * @throws NullPointerException If {@code name} is {@code null}
2661 * @since 1.1
2662 */
2663 @CallerSensitive
2664 public URL getResource(String name) {
2665 name = resolveName(name);
2666
2667 Module thisModule = getModule();
2668 if (thisModule.isNamed()) {
2669 // check if resource can be located by caller
2670 if (Resources.canEncapsulate(name)
2671 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2672 return null;
2673 }
2674
2675 // resource not encapsulated or in package open to caller
2676 String mn = thisModule.getName();
2677 ClassLoader cl = classLoader;
2678 try {
2679 if (cl == null) {
2680 return BootLoader.findResource(mn, name);
2681 } else {
2682 return cl.findResource(mn, name);
2683 }
2684 } catch (IOException ioe) {
2685 return null;
2686 }
2687 }
2688
2689 // unnamed module
2690 ClassLoader cl = classLoader;
2691 if (cl == null) {
2692 return ClassLoader.getSystemResource(name);
2693 } else {
2694 return cl.getResource(name);
2695 }
2696 }
2697
2698 /**
2699 * Returns true if a resource with the given name can be located by the
2700 * given caller. All resources in a module can be located by code in
2701 * the module. For other callers, then the package needs to be open to
2702 * the caller.
2703 */
2704 private boolean isOpenToCaller(String name, Class<?> caller) {
2705 // assert getModule().isNamed();
2706 Module thisModule = getModule();
2707 Module callerModule = (caller != null) ? caller.getModule() : null;
2708 if (callerModule != thisModule) {
2709 String pn = Resources.toPackageName(name);
2710 if (thisModule.getDescriptor().packages().contains(pn)) {
2711 if (callerModule == null) {
2712 // no caller, return true if the package is open to all modules
2713 return thisModule.isOpen(pn);
2714 }
2715 if (!thisModule.isOpen(pn, callerModule)) {
2716 // package not open to caller
2717 return false;
2718 }
2719 }
2720 }
2721 return true;
2722 }
2723
2724 private transient final ProtectionDomain protectionDomain;
2725
2726 /** Holder for the protection domain returned when the internal domain is null */
2727 private static class Holder {
2728 private static final ProtectionDomain allPermDomain;
2729 static {
2730 Permissions perms = new Permissions();
2731 perms.add(new AllPermission());
2732 allPermDomain = new ProtectionDomain(null, perms);
2733 }
2734 }
2735
2736 /**
2737 * Returns the {@code ProtectionDomain} of this class.
2738 *
2739 * @return the ProtectionDomain of this class
2740 *
2741 * @see java.security.ProtectionDomain
2742 * @since 1.2
2743 */
2744 public ProtectionDomain getProtectionDomain() {
2745 if (protectionDomain == null) {
2746 return Holder.allPermDomain;
2747 } else {
2748 return protectionDomain;
2749 }
2750 }
2751
2752 /*
2753 * Returns the Class object for the named primitive type. Type parameter T
2754 * avoids redundant casts for trusted code.
2755 */
2756 static native <T> Class<T> getPrimitiveClass(String name);
2757
2758 /**
2759 * Add a package name prefix if the name is not absolute. Remove leading "/"
2760 * if name is absolute
2761 */
2762 private String resolveName(String name) {
2763 if (!name.startsWith("/")) {
2764 String baseName = getPackageName();
2765 if (!baseName.isEmpty()) {
2766 int len = baseName.length() + 1 + name.length();
2767 StringBuilder sb = new StringBuilder(len);
2768 name = sb.append(baseName.replace('.', '/'))
2769 .append('/')
2770 .append(name)
2771 .toString();
2772 }
2773 } else {
2774 name = name.substring(1);
2775 }
2776 return name;
2777 }
2778
2779 /**
2780 * Atomic operations support.
2781 */
2782 private static class Atomic {
2783 // initialize Unsafe machinery here, since we need to call Class.class instance method
2784 // and have to avoid calling it in the static initializer of the Class class...
2785 private static final Unsafe unsafe = Unsafe.getUnsafe();
2786 // offset of Class.reflectionData instance field
2787 private static final long reflectionDataOffset
2788 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2789 // offset of Class.annotationType instance field
2790 private static final long annotationTypeOffset
2791 = unsafe.objectFieldOffset(Class.class, "annotationType");
2792 // offset of Class.annotationData instance field
2793 private static final long annotationDataOffset
2794 = unsafe.objectFieldOffset(Class.class, "annotationData");
2795
2796 static <T> boolean casReflectionData(Class<?> clazz,
2797 ReflectionData<T> oldData,
2798 ReflectionData<T> newData) {
2799 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2800 }
2801
2802 static boolean casAnnotationType(Class<?> clazz,
2803 AnnotationType oldType,
2804 AnnotationType newType) {
2805 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2806 }
2807
2808 static boolean casAnnotationData(Class<?> clazz,
2809 AnnotationData oldData,
2810 AnnotationData newData) {
2811 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2812 }
2813 }
2814
2815 /**
2816 * Reflection support.
2817 */
2818
2819 // Reflection data caches various derived names and reflective members. Cached
2820 // values may be invalidated when JVM TI RedefineClasses() is called
2821 private static class ReflectionData<T> {
2822 volatile Field[] declaredFields;
2823 volatile Field[] publicFields;
2824 volatile Method[] declaredMethods;
2825 volatile Method[] publicMethods;
2826 volatile Constructor<T>[] declaredConstructors;
2827 volatile Constructor<T>[] publicConstructors;
2828 // Intermediate results for getFields and getMethods
2829 volatile Field[] declaredPublicFields;
2830 volatile Method[] declaredPublicMethods;
2831 volatile Class<?>[] interfaces;
2832
2833 // Cached names
2834 String simpleName;
2835 String canonicalName;
2836 static final String NULL_SENTINEL = new String();
2837
2838 // Value of classRedefinedCount when we created this ReflectionData instance
2839 final int redefinedCount;
2840
2841 ReflectionData(int redefinedCount) {
2842 this.redefinedCount = redefinedCount;
2843 }
2844 }
2845
2846 private transient volatile ReflectionData<T> reflectionData;
2847
2848 // Incremented by the VM on each call to JVM TI RedefineClasses()
2849 // that redefines this class or a superclass.
2850 private transient volatile int classRedefinedCount;
2851
2852 // Lazily create and cache ReflectionData
2853 private ReflectionData<T> reflectionData() {
2854 ReflectionData<T> reflectionData = this.reflectionData;
2855 int classRedefinedCount = this.classRedefinedCount;
2856 if (reflectionData != null &&
2857 reflectionData.redefinedCount == classRedefinedCount) {
2858 return reflectionData;
2859 }
2860 // else no SoftReference or cleared SoftReference or stale ReflectionData
2861 // -> create and replace new instance
2862 return newReflectionData(reflectionData, classRedefinedCount);
2863 }
2864
2865 private ReflectionData<T> newReflectionData(ReflectionData<T> oldReflectionData,
2866 int classRedefinedCount) {
2867 while (true) {
2868 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2869 // try to CAS it...
2870 if (Atomic.casReflectionData(this, oldReflectionData, rd)) {
2871 return rd;
2872 }
2873 // else retry
2874 oldReflectionData = this.reflectionData;
2875 classRedefinedCount = this.classRedefinedCount;
2876 if (oldReflectionData != null && oldReflectionData.redefinedCount == classRedefinedCount) {
2877 return rd;
2878 }
2879 }
2880 }
2881
2882 // Generic signature handling
2883 private native String getGenericSignature0();
2884
2885 // Generic info repository; lazily initialized
2886 private transient volatile ClassRepository genericInfo;
2887
2888 // accessor for factory
2889 private GenericsFactory getFactory() {
2890 // create scope and factory
2891 return CoreReflectionFactory.make(this, ClassScope.make(this));
2892 }
2893
2894 // accessor for generic info repository;
2895 // generic info is lazily initialized
2896 private ClassRepository getGenericInfo() {
2897 ClassRepository genericInfo = this.genericInfo;
2898 if (genericInfo == null) {
2899 String signature = getGenericSignature0();
2900 if (signature == null) {
2901 genericInfo = ClassRepository.NONE;
2902 } else {
2903 genericInfo = ClassRepository.make(signature, getFactory());
2904 }
2905 this.genericInfo = genericInfo;
2906 }
2907 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2908 }
2909
2910 // Annotations handling
2911 native byte[] getRawAnnotations();
2912 // Since 1.8
2913 native byte[] getRawTypeAnnotations();
2914 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2915 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2916 }
2917
2918 native ConstantPool getConstantPool();
2919
2920 //
2921 //
2922 // java.lang.reflect.Field handling
2923 //
2924 //
2925
2926 // Returns an array of "root" fields. These Field objects must NOT
2927 // be propagated to the outside world, but must instead be copied
2928 // via ReflectionFactory.copyField.
2929 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2930 Field[] res;
2931 ReflectionData<T> rd = reflectionData();
2932 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2933 if (res != null) return res;
2934 // No cached value available; request value from VM
2935 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2936 if (publicOnly) {
2937 rd.declaredPublicFields = res;
2938 } else {
2939 rd.declaredFields = res;
2940 }
2941 return res;
2942 }
2943
2944 // Returns an array of "root" fields. These Field objects must NOT
2945 // be propagated to the outside world, but must instead be copied
2946 // via ReflectionFactory.copyField.
2947 private Field[] privateGetPublicFields() {
2948 Field[] res;
2949 ReflectionData<T> rd = reflectionData();
2950 res = rd.publicFields;
2951 if (res != null) return res;
2952
2953 // Use a linked hash set to ensure order is preserved and
2954 // fields from common super interfaces are not duplicated
2955 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2956
2957 // Local fields
2958 addAll(fields, privateGetDeclaredFields(true));
2959
2960 // Direct superinterfaces, recursively
2961 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2962 addAll(fields, si.privateGetPublicFields());
2963 }
2964
2965 // Direct superclass, recursively
2966 Class<?> sc = getSuperclass();
2967 if (sc != null) {
2968 addAll(fields, sc.privateGetPublicFields());
2969 }
2970
2971 res = fields.toArray(new Field[0]);
2972 rd.publicFields = res;
2973 return res;
2974 }
2975
2976 private static void addAll(Collection<Field> c, Field[] o) {
2977 for (Field f : o) {
2978 c.add(f);
2979 }
2980 }
2981
2982
2983 //
2984 //
2985 // java.lang.reflect.Constructor handling
2986 //
2987 //
2988
2989 // Returns an array of "root" constructors. These Constructor
2990 // objects must NOT be propagated to the outside world, but must
2991 // instead be copied via ReflectionFactory.copyConstructor.
2992 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
2993 Constructor<T>[] res;
2994 ReflectionData<T> rd = reflectionData();
2995 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
2996 if (res != null) return res;
2997 // No cached value available; request value from VM
2998 if (isInterface()) {
2999 @SuppressWarnings("unchecked")
3000 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3001 res = temporaryRes;
3002 } else {
3003 res = getDeclaredConstructors0(publicOnly);
3004 }
3005 if (publicOnly) {
3006 rd.publicConstructors = res;
3007 } else {
3008 rd.declaredConstructors = res;
3009 }
3010 return res;
3011 }
3012
3013 //
3014 //
3015 // java.lang.reflect.Method handling
3016 //
3017 //
3018
3019 // Returns an array of "root" methods. These Method objects must NOT
3020 // be propagated to the outside world, but must instead be copied
3021 // via ReflectionFactory.copyMethod.
3022 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3023 Method[] res;
3024 ReflectionData<T> rd = reflectionData();
3025 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3026 if (res != null) return res;
3027 // No cached value available; request value from VM
3028 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3029 if (publicOnly) {
3030 rd.declaredPublicMethods = res;
3031 } else {
3032 rd.declaredMethods = res;
3033 }
3034 return res;
3035 }
3036
3037 // Returns an array of "root" methods. These Method objects must NOT
3038 // be propagated to the outside world, but must instead be copied
3039 // via ReflectionFactory.copyMethod.
3040 private Method[] privateGetPublicMethods() {
3041 Method[] res;
3042 ReflectionData<T> rd = reflectionData();
3043 res = rd.publicMethods;
3044 if (res != null) return res;
3045
3046 // No cached value available; compute value recursively.
3047 // Start by fetching public declared methods...
3048 PublicMethods pms = new PublicMethods();
3049 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3050 pms.merge(m);
3051 }
3052 // ...then recur over superclass methods...
3053 Class<?> sc = getSuperclass();
3054 if (sc != null) {
3055 for (Method m : sc.privateGetPublicMethods()) {
3056 pms.merge(m);
3057 }
3058 }
3059 // ...and finally over direct superinterfaces.
3060 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3061 for (Method m : intf.privateGetPublicMethods()) {
3062 // static interface methods are not inherited
3063 if (!Modifier.isStatic(m.getModifiers())) {
3064 pms.merge(m);
3065 }
3066 }
3067 }
3068
3069 res = pms.toArray();
3070 rd.publicMethods = res;
3071 return res;
3072 }
3073
3074
3075 //
3076 // Helpers for fetchers of one field, method, or constructor
3077 //
3078
3079 // This method does not copy the returned Field object!
3080 private static Field searchFields(Field[] fields, String name) {
3081 for (Field field : fields) {
3082 if (field.getName().equals(name)) {
3083 return field;
3084 }
3085 }
3086 return null;
3087 }
3088
3089 // Returns a "root" Field object. This Field object must NOT
3090 // be propagated to the outside world, but must instead be copied
3091 // via ReflectionFactory.copyField.
3092 private Field getField0(String name) {
3093 // Note: the intent is that the search algorithm this routine
3094 // uses be equivalent to the ordering imposed by
3095 // privateGetPublicFields(). It fetches only the declared
3096 // public fields for each class, however, to reduce the number
3097 // of Field objects which have to be created for the common
3098 // case where the field being requested is declared in the
3099 // class which is being queried.
3100 Field res;
3101 // Search declared public fields
3102 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3103 return res;
3104 }
3105 // Direct superinterfaces, recursively
3106 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3107 for (Class<?> c : interfaces) {
3108 if ((res = c.getField0(name)) != null) {
3109 return res;
3110 }
3111 }
3112 // Direct superclass, recursively
3113 if (!isInterface()) {
3114 Class<?> c = getSuperclass();
3115 if (c != null) {
3116 if ((res = c.getField0(name)) != null) {
3117 return res;
3118 }
3119 }
3120 }
3121 return null;
3122 }
3123
3124 // This method does not copy the returned Method object!
3125 private static Method searchMethods(Method[] methods,
3126 String name,
3127 Class<?>[] parameterTypes)
3128 {
3129 ReflectionFactory fact = getReflectionFactory();
3130 Method res = null;
3131 for (Method m : methods) {
3132 if (m.getName().equals(name)
3133 && arrayContentsEq(parameterTypes,
3134 fact.getExecutableSharedParameterTypes(m))
3135 && (res == null
3136 || (res.getReturnType() != m.getReturnType()
3137 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3138 res = m;
3139 }
3140 return res;
3141 }
3142
3143 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3144
3145 // Returns a "root" Method object. This Method object must NOT
3146 // be propagated to the outside world, but must instead be copied
3147 // via ReflectionFactory.copyMethod.
3148 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3149 PublicMethods.MethodList res = getMethodsRecursive(
3150 name,
3151 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3152 /* includeStatic */ true, /* publicOnly */ true);
3153 return res == null ? null : res.getMostSpecific();
3154 }
3155
3156 // Returns a list of "root" Method objects. These Method objects must NOT
3157 // be propagated to the outside world, but must instead be copied
3158 // via ReflectionFactory.copyMethod.
3159 private PublicMethods.MethodList getMethodsRecursive(String name,
3160 Class<?>[] parameterTypes,
3161 boolean includeStatic,
3162 boolean publicOnly) {
3163 // 1st check declared methods
3164 Method[] methods = privateGetDeclaredMethods(publicOnly);
3165 PublicMethods.MethodList res = PublicMethods.MethodList
3166 .filter(methods, name, parameterTypes, includeStatic);
3167 // if there is at least one match among declared methods, we need not
3168 // search any further as such match surely overrides matching methods
3169 // declared in superclass(es) or interface(s).
3170 if (res != null) {
3171 return res;
3172 }
3173
3174 // if there was no match among declared methods,
3175 // we must consult the superclass (if any) recursively...
3176 Class<?> sc = getSuperclass();
3177 if (sc != null) {
3178 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3179 }
3180
3181 // ...and coalesce the superclass methods with methods obtained
3182 // from directly implemented interfaces excluding static methods...
3183 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3184 res = PublicMethods.MethodList.merge(
3185 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3186 }
3187
3188 return res;
3189 }
3190
3191 // Returns a "root" Constructor object. This Constructor object must NOT
3192 // be propagated to the outside world, but must instead be copied
3193 // via ReflectionFactory.copyConstructor.
3194 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3195 int which) throws NoSuchMethodException
3196 {
3197 ReflectionFactory fact = getReflectionFactory();
3198 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3199 for (Constructor<T> constructor : constructors) {
3200 if (arrayContentsEq(parameterTypes,
3201 fact.getExecutableSharedParameterTypes(constructor))) {
3202 return constructor;
3203 }
3204 }
3205 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3206 }
3207
3208 //
3209 // Other helpers and base implementation
3210 //
3211
3212 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3213 if (a1 == null) {
3214 return a2 == null || a2.length == 0;
3215 }
3216
3217 if (a2 == null) {
3218 return a1.length == 0;
3219 }
3220
3221 if (a1.length != a2.length) {
3222 return false;
3223 }
3224
3225 for (int i = 0; i < a1.length; i++) {
3226 if (a1[i] != a2[i]) {
3227 return false;
3228 }
3229 }
3230
3231 return true;
3232 }
3233
3234 private static Field[] copyFields(Field[] arg) {
3235 Field[] out = new Field[arg.length];
3236 ReflectionFactory fact = getReflectionFactory();
3237 for (int i = 0; i < arg.length; i++) {
3238 out[i] = fact.copyField(arg[i]);
3239 }
3240 return out;
3241 }
3242
3243 private static Method[] copyMethods(Method[] arg) {
3244 Method[] out = new Method[arg.length];
3245 ReflectionFactory fact = getReflectionFactory();
3246 for (int i = 0; i < arg.length; i++) {
3247 out[i] = fact.copyMethod(arg[i]);
3248 }
3249 return out;
3250 }
3251
3252 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3253 Constructor<U>[] out = arg.clone();
3254 ReflectionFactory fact = getReflectionFactory();
3255 for (int i = 0; i < out.length; i++) {
3256 out[i] = fact.copyConstructor(out[i]);
3257 }
3258 return out;
3259 }
3260
3261 private native Field[] getDeclaredFields0(boolean publicOnly);
3262 private native Method[] getDeclaredMethods0(boolean publicOnly);
3263 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3264 private native Class<?>[] getDeclaredClasses0();
3265
3266 /*
3267 * Returns an array containing the components of the Record attribute,
3268 * or null if the attribute is not present.
3269 *
3270 * Note that this method returns non-null array on a class with
3271 * the Record attribute even if this class is not a record.
3272 */
3273 private native RecordComponent[] getRecordComponents0();
3274 private native boolean isRecord0();
3275
3276 /**
3277 * Helper method to get the method name from arguments.
3278 */
3279 private String methodToString(String name, Class<?>[] argTypes) {
3280 return getName() + '.' + name +
3281 ((argTypes == null || argTypes.length == 0) ?
3282 "()" :
3283 Arrays.stream(argTypes)
3284 .map(c -> c == null ? "null" : c.getName())
3285 .collect(Collectors.joining(",", "(", ")")));
3286 }
3287
3288 /** use serialVersionUID from JDK 1.1 for interoperability */
3289 @java.io.Serial
3290 private static final long serialVersionUID = 3206093459760846163L;
3291
3292
3293 /**
3294 * Class Class is special cased within the Serialization Stream Protocol.
3295 *
3296 * A Class instance is written initially into an ObjectOutputStream in the
3297 * following format:
3298 * <pre>
3299 * {@code TC_CLASS} ClassDescriptor
3300 * A ClassDescriptor is a special cased serialization of
3301 * a {@code java.io.ObjectStreamClass} instance.
3302 * </pre>
3303 * A new handle is generated for the initial time the class descriptor
3304 * is written into the stream. Future references to the class descriptor
3305 * are written as references to the initial class descriptor instance.
3306 *
3307 * @see java.io.ObjectStreamClass
3308 */
3309 @java.io.Serial
3310 private static final ObjectStreamField[] serialPersistentFields =
3311 new ObjectStreamField[0];
3312
3313
3314 /**
3315 * Returns the assertion status that would be assigned to this
3316 * class if it were to be initialized at the time this method is invoked.
3317 * If this class has had its assertion status set, the most recent
3318 * setting will be returned; otherwise, if any package default assertion
3319 * status pertains to this class, the most recent setting for the most
3320 * specific pertinent package default assertion status is returned;
3321 * otherwise, if this class is not a system class (i.e., it has a
3322 * class loader) its class loader's default assertion status is returned;
3323 * otherwise, the system class default assertion status is returned.
3324 *
3325 * @apiNote
3326 * Few programmers will have any need for this method; it is provided
3327 * for the benefit of the JDK itself. (It allows a class to determine at
3328 * the time that it is initialized whether assertions should be enabled.)
3329 * Note that this method is not guaranteed to return the actual
3330 * assertion status that was (or will be) associated with the specified
3331 * class when it was (or will be) initialized.
3332 *
3333 * @return the desired assertion status of the specified class.
3334 * @see java.lang.ClassLoader#setClassAssertionStatus
3335 * @see java.lang.ClassLoader#setPackageAssertionStatus
3336 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3337 * @since 1.4
3338 */
3339 public boolean desiredAssertionStatus() {
3340 ClassLoader loader = classLoader;
3341 // If the loader is null this is a system class, so ask the VM
3342 if (loader == null)
3343 return desiredAssertionStatus0(this);
3344
3345 // If the classloader has been initialized with the assertion
3346 // directives, ask it. Otherwise, ask the VM.
3347 synchronized(loader.assertionLock) {
3348 if (loader.classAssertionStatus != null) {
3349 return loader.desiredAssertionStatus(getName());
3350 }
3351 }
3352 return desiredAssertionStatus0(this);
3353 }
3354
3355 // Retrieves the desired assertion status of this class from the VM
3356 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3357
3358 /**
3359 * Returns true if and only if this class was declared as an enum in the
3360 * source code.
3361 *
3362 * Note that {@link java.lang.Enum} is not itself an enum class.
3363 *
3364 * Also note that if an enum constant is declared with a class body,
3365 * the class of that enum constant object is an anonymous class
3366 * and <em>not</em> the class of the declaring enum class. The
3367 * {@link Enum#getDeclaringClass} method of an enum constant can
3368 * be used to get the class of the enum class declaring the
3369 * constant.
3370 *
3371 * @return true if and only if this class was declared as an enum in the
3372 * source code
3373 * @since 1.5
3374 * @jls 8.9.1 Enum Constants
3375 */
3376 public boolean isEnum() {
3377 // An enum must both directly extend java.lang.Enum and have
3378 // the ENUM bit set; classes for specialized enum constants
3379 // don't do the former.
3380 return (this.getModifiers() & ENUM) != 0 &&
3381 this.getSuperclass() == java.lang.Enum.class;
3382 }
3383
3384 /**
3385 * Returns {@code true} if and only if this class is a record class.
3386 *
3387 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3388 * class is {@code java.lang.Record}. A record class is {@linkplain
3389 * Modifier#FINAL final}. A record class has (possibly zero) record
3390 * components; {@link #getRecordComponents()} returns a non-null but
3391 * possibly empty value for a record.
3392 *
3393 * <p> Note that class {@link Record} is not a record class and thus
3394 * invoking this method on class {@code Record} returns {@code false}.
3395 *
3396 * @return true if and only if this class is a record class, otherwise false
3397 * @jls 8.10 Record Classes
3398 * @since 16
3399 */
3400 public boolean isRecord() {
3401 // this superclass and final modifier check is not strictly necessary
3402 // they are intrinsified and serve as a fast-path check
3403 return getSuperclass() == java.lang.Record.class &&
3404 (this.getModifiers() & Modifier.FINAL) != 0 &&
3405 isRecord0();
3406 }
3407
3408 // Fetches the factory for reflective objects
3409 private static ReflectionFactory getReflectionFactory() {
3410 var factory = reflectionFactory;
3411 if (factory != null) {
3412 return factory;
3413 }
3414 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3415 }
3416 private static ReflectionFactory reflectionFactory;
3417
3418 /**
3419 * When CDS is enabled, the Class class may be aot-initialized. However,
3420 * we can't archive reflectionFactory, so we reset it to null, so it
3421 * will be allocated again at runtime.
3422 */
3423 private static void resetArchivedStates() {
3424 reflectionFactory = null;
3425 }
3426
3427 /**
3428 * Returns the elements of this enum class or null if this
3429 * Class object does not represent an enum class.
3430 *
3431 * @return an array containing the values comprising the enum class
3432 * represented by this {@code Class} object in the order they're
3433 * declared, or null if this {@code Class} object does not
3434 * represent an enum class
3435 * @since 1.5
3436 * @jls 8.9.1 Enum Constants
3437 */
3438 public T[] getEnumConstants() {
3439 T[] values = getEnumConstantsShared();
3440 return (values != null) ? values.clone() : null;
3441 }
3442
3443 /**
3444 * Returns the elements of this enum class or null if this
3445 * Class object does not represent an enum class;
3446 * identical to getEnumConstants except that the result is
3447 * uncloned, cached, and shared by all callers.
3448 */
3449 T[] getEnumConstantsShared() {
3450 T[] constants = enumConstants;
3451 if (constants == null) {
3452 if (!isEnum()) return null;
3453 try {
3454 final Method values = getMethod("values");
3455 values.setAccessible(true);
3456 @SuppressWarnings("unchecked")
3457 T[] temporaryConstants = (T[])values.invoke(null);
3458 enumConstants = constants = temporaryConstants;
3459 }
3460 // These can happen when users concoct enum-like classes
3461 // that don't comply with the enum spec.
3462 catch (InvocationTargetException | NoSuchMethodException |
3463 IllegalAccessException | NullPointerException |
3464 ClassCastException ex) { return null; }
3465 }
3466 return constants;
3467 }
3468 private transient volatile T[] enumConstants;
3469
3470 /**
3471 * Returns a map from simple name to enum constant. This package-private
3472 * method is used internally by Enum to implement
3473 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3474 * efficiently. Note that the map is returned by this method is
3475 * created lazily on first use. Typically it won't ever get created.
3476 */
3477 Map<String, T> enumConstantDirectory() {
3478 Map<String, T> directory = enumConstantDirectory;
3479 if (directory == null) {
3480 T[] universe = getEnumConstantsShared();
3481 if (universe == null)
3482 throw new IllegalArgumentException(
3483 getName() + " is not an enum class");
3484 directory = HashMap.newHashMap(universe.length);
3485 for (T constant : universe) {
3486 directory.put(((Enum<?>)constant).name(), constant);
3487 }
3488 enumConstantDirectory = directory;
3489 }
3490 return directory;
3491 }
3492 private transient volatile Map<String, T> enumConstantDirectory;
3493
3494 /**
3495 * Casts an object to the class or interface represented
3496 * by this {@code Class} object.
3497 *
3498 * @param obj the object to be cast
3499 * @return the object after casting, or null if obj is null
3500 *
3501 * @throws ClassCastException if the object is not
3502 * null and is not assignable to the type T.
3503 *
3504 * @since 1.5
3505 */
3506 @SuppressWarnings("unchecked")
3507 @IntrinsicCandidate
3508 public T cast(Object obj) {
3509 if (obj != null && !isInstance(obj))
3510 throw new ClassCastException(cannotCastMsg(obj));
3511 return (T) obj;
3512 }
3513
3514 private String cannotCastMsg(Object obj) {
3515 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3516 }
3517
3518 /**
3519 * Casts this {@code Class} object to represent a subclass of the class
3520 * represented by the specified class object. Checks that the cast
3521 * is valid, and throws a {@code ClassCastException} if it is not. If
3522 * this method succeeds, it always returns a reference to this {@code Class} object.
3523 *
3524 * <p>This method is useful when a client needs to "narrow" the type of
3525 * a {@code Class} object to pass it to an API that restricts the
3526 * {@code Class} objects that it is willing to accept. A cast would
3527 * generate a compile-time warning, as the correctness of the cast
3528 * could not be checked at runtime (because generic types are implemented
3529 * by erasure).
3530 *
3531 * @param <U> the type to cast this {@code Class} object to
3532 * @param clazz the class of the type to cast this {@code Class} object to
3533 * @return this {@code Class} object, cast to represent a subclass of
3534 * the specified class object.
3535 * @throws ClassCastException if this {@code Class} object does not
3536 * represent a subclass of the specified class (here "subclass" includes
3537 * the class itself).
3538 * @since 1.5
3539 */
3540 @SuppressWarnings("unchecked")
3541 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3542 if (clazz.isAssignableFrom(this))
3543 return (Class<? extends U>) this;
3544 else
3545 throw new ClassCastException(this.toString());
3546 }
3547
3548 /**
3549 * {@inheritDoc}
3550 * <p>Note that any annotation returned by this method is a
3551 * declaration annotation.
3552 *
3553 * @throws NullPointerException {@inheritDoc}
3554 * @since 1.5
3555 */
3556 @Override
3557 @SuppressWarnings("unchecked")
3558 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3559 Objects.requireNonNull(annotationClass);
3560
3561 return (A) annotationData().annotations.get(annotationClass);
3562 }
3563
3564 /**
3565 * {@inheritDoc}
3566 * @throws NullPointerException {@inheritDoc}
3567 * @since 1.5
3568 */
3569 @Override
3570 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3571 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3572 }
3573
3574 /**
3575 * {@inheritDoc}
3576 * <p>Note that any annotations returned by this method are
3577 * declaration annotations.
3578 *
3579 * @throws NullPointerException {@inheritDoc}
3580 * @since 1.8
3581 */
3582 @Override
3583 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3584 Objects.requireNonNull(annotationClass);
3585
3586 AnnotationData annotationData = annotationData();
3587 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3588 this,
3589 annotationClass);
3590 }
3591
3592 /**
3593 * {@inheritDoc}
3594 * <p>Note that any annotations returned by this method are
3595 * declaration annotations.
3596 *
3597 * @since 1.5
3598 */
3599 @Override
3600 public Annotation[] getAnnotations() {
3601 return AnnotationParser.toArray(annotationData().annotations);
3602 }
3603
3604 /**
3605 * {@inheritDoc}
3606 * <p>Note that any annotation returned by this method is a
3607 * declaration annotation.
3608 *
3609 * @throws NullPointerException {@inheritDoc}
3610 * @since 1.8
3611 */
3612 @Override
3613 @SuppressWarnings("unchecked")
3614 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3615 Objects.requireNonNull(annotationClass);
3616
3617 return (A) annotationData().declaredAnnotations.get(annotationClass);
3618 }
3619
3620 /**
3621 * {@inheritDoc}
3622 * <p>Note that any annotations returned by this method are
3623 * declaration annotations.
3624 *
3625 * @throws NullPointerException {@inheritDoc}
3626 * @since 1.8
3627 */
3628 @Override
3629 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3630 Objects.requireNonNull(annotationClass);
3631
3632 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3633 annotationClass);
3634 }
3635
3636 /**
3637 * {@inheritDoc}
3638 * <p>Note that any annotations returned by this method are
3639 * declaration annotations.
3640 *
3641 * @since 1.5
3642 */
3643 @Override
3644 public Annotation[] getDeclaredAnnotations() {
3645 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3646 }
3647
3648 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3649 private static class AnnotationData {
3650 final Map<Class<? extends Annotation>, Annotation> annotations;
3651 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3652
3653 // Value of classRedefinedCount when we created this AnnotationData instance
3654 final int redefinedCount;
3655
3656 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3657 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3658 int redefinedCount) {
3659 this.annotations = annotations;
3660 this.declaredAnnotations = declaredAnnotations;
3661 this.redefinedCount = redefinedCount;
3662 }
3663 }
3664
3665 // Annotations cache
3666 @SuppressWarnings("UnusedDeclaration")
3667 private transient volatile AnnotationData annotationData;
3668
3669 private AnnotationData annotationData() {
3670 while (true) { // retry loop
3671 AnnotationData annotationData = this.annotationData;
3672 int classRedefinedCount = this.classRedefinedCount;
3673 if (annotationData != null &&
3674 annotationData.redefinedCount == classRedefinedCount) {
3675 return annotationData;
3676 }
3677 // null or stale annotationData -> optimistically create new instance
3678 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3679 // try to install it
3680 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3681 // successfully installed new AnnotationData
3682 return newAnnotationData;
3683 }
3684 }
3685 }
3686
3687 private AnnotationData createAnnotationData(int classRedefinedCount) {
3688 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3689 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3690 Class<?> superClass = getSuperclass();
3691 Map<Class<? extends Annotation>, Annotation> annotations = null;
3692 if (superClass != null) {
3693 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3694 superClass.annotationData().annotations;
3695 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3696 Class<? extends Annotation> annotationClass = e.getKey();
3697 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3698 if (annotations == null) { // lazy construction
3699 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3700 declaredAnnotations.size(),
3701 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3702 )
3703 );
3704 }
3705 annotations.put(annotationClass, e.getValue());
3706 }
3707 }
3708 }
3709 if (annotations == null) {
3710 // no inherited annotations -> share the Map with declaredAnnotations
3711 annotations = declaredAnnotations;
3712 } else {
3713 // at least one inherited annotation -> declared may override inherited
3714 annotations.putAll(declaredAnnotations);
3715 }
3716 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3717 }
3718
3719 // Annotation interfaces cache their internal (AnnotationType) form
3720
3721 @SuppressWarnings("UnusedDeclaration")
3722 private transient volatile AnnotationType annotationType;
3723
3724 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3725 return Atomic.casAnnotationType(this, oldType, newType);
3726 }
3727
3728 AnnotationType getAnnotationType() {
3729 return annotationType;
3730 }
3731
3732 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3733 return annotationData().declaredAnnotations;
3734 }
3735
3736 /* Backing store of user-defined values pertaining to this class.
3737 * Maintained by the ClassValue class.
3738 */
3739 transient ClassValue.ClassValueMap classValueMap;
3740
3741 /**
3742 * Returns an {@code AnnotatedType} object that represents the use of a
3743 * type to specify the superclass of the entity represented by this {@code
3744 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3745 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3746 * Foo.)
3747 *
3748 * <p> If this {@code Class} object represents a class whose declaration
3749 * does not explicitly indicate an annotated superclass, then the return
3750 * value is an {@code AnnotatedType} object representing an element with no
3751 * annotations.
3752 *
3753 * <p> If this {@code Class} represents either the {@code Object} class, an
3754 * interface type, an array type, a primitive type, or void, the return
3755 * value is {@code null}.
3756 *
3757 * @return an object representing the superclass
3758 * @since 1.8
3759 */
3760 public AnnotatedType getAnnotatedSuperclass() {
3761 if (this == Object.class ||
3762 isInterface() ||
3763 isArray() ||
3764 isPrimitive() ||
3765 this == Void.TYPE) {
3766 return null;
3767 }
3768
3769 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3770 }
3771
3772 /**
3773 * Returns an array of {@code AnnotatedType} objects that represent the use
3774 * of types to specify superinterfaces of the entity represented by this
3775 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3776 * superinterface in '... implements Foo' is distinct from the
3777 * <em>declaration</em> of interface Foo.)
3778 *
3779 * <p> If this {@code Class} object represents a class, the return value is
3780 * an array containing objects representing the uses of interface types to
3781 * specify interfaces implemented by the class. The order of the objects in
3782 * the array corresponds to the order of the interface types used in the
3783 * 'implements' clause of the declaration of this {@code Class} object.
3784 *
3785 * <p> If this {@code Class} object represents an interface, the return
3786 * value is an array containing objects representing the uses of interface
3787 * types to specify interfaces directly extended by the interface. The
3788 * order of the objects in the array corresponds to the order of the
3789 * interface types used in the 'extends' clause of the declaration of this
3790 * {@code Class} object.
3791 *
3792 * <p> If this {@code Class} object represents a class or interface whose
3793 * declaration does not explicitly indicate any annotated superinterfaces,
3794 * the return value is an array of length 0.
3795 *
3796 * <p> If this {@code Class} object represents either the {@code Object}
3797 * class, an array type, a primitive type, or void, the return value is an
3798 * array of length 0.
3799 *
3800 * @return an array representing the superinterfaces
3801 * @since 1.8
3802 */
3803 public AnnotatedType[] getAnnotatedInterfaces() {
3804 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3805 }
3806
3807 private native Class<?> getNestHost0();
3808
3809 /**
3810 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3811 * or interface represented by this {@code Class} object belongs.
3812 * Every class and interface belongs to exactly one nest.
3813 *
3814 * If the nest host of this class or interface has previously
3815 * been determined, then this method returns the nest host.
3816 * If the nest host of this class or interface has
3817 * not previously been determined, then this method determines the nest
3818 * host using the algorithm of JVMS 5.4.4, and returns it.
3819 *
3820 * Often, a class or interface belongs to a nest consisting only of itself,
3821 * in which case this method returns {@code this} to indicate that the class
3822 * or interface is the nest host.
3823 *
3824 * <p>If this {@code Class} object represents a primitive type, an array type,
3825 * or {@code void}, then this method returns {@code this},
3826 * indicating that the represented entity belongs to the nest consisting only of
3827 * itself, and is the nest host.
3828 *
3829 * @return the nest host of this class or interface
3830 *
3831 * @since 11
3832 * @jvms 4.7.28 The {@code NestHost} Attribute
3833 * @jvms 4.7.29 The {@code NestMembers} Attribute
3834 * @jvms 5.4.4 Access Control
3835 */
3836 public Class<?> getNestHost() {
3837 if (isPrimitive() || isArray()) {
3838 return this;
3839 }
3840 return getNestHost0();
3841 }
3842
3843 /**
3844 * Determines if the given {@code Class} is a nestmate of the
3845 * class or interface represented by this {@code Class} object.
3846 * Two classes or interfaces are nestmates
3847 * if they have the same {@linkplain #getNestHost() nest host}.
3848 *
3849 * @param c the class to check
3850 * @return {@code true} if this class and {@code c} are members of
3851 * the same nest; and {@code false} otherwise.
3852 *
3853 * @since 11
3854 */
3855 public boolean isNestmateOf(Class<?> c) {
3856 if (this == c) {
3857 return true;
3858 }
3859 if (isPrimitive() || isArray() ||
3860 c.isPrimitive() || c.isArray()) {
3861 return false;
3862 }
3863
3864 return getNestHost() == c.getNestHost();
3865 }
3866
3867 private native Class<?>[] getNestMembers0();
3868
3869 /**
3870 * Returns an array containing {@code Class} objects representing all the
3871 * classes and interfaces that are members of the nest to which the class
3872 * or interface represented by this {@code Class} object belongs.
3873 *
3874 * First, this method obtains the {@linkplain #getNestHost() nest host},
3875 * {@code H}, of the nest to which the class or interface represented by
3876 * this {@code Class} object belongs. The zeroth element of the returned
3877 * array is {@code H}.
3878 *
3879 * Then, for each class or interface {@code C} which is recorded by {@code H}
3880 * as being a member of its nest, this method attempts to obtain the {@code Class}
3881 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3882 * loader} of the current {@code Class} object), and then obtains the
3883 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3884 * The classes and interfaces which are recorded by {@code H} as being members
3885 * of its nest, and for which {@code H} can be determined as their nest host,
3886 * are indicated by subsequent elements of the returned array. The order of
3887 * such elements is unspecified. Duplicates are permitted.
3888 *
3889 * <p>If this {@code Class} object represents a primitive type, an array type,
3890 * or {@code void}, then this method returns a single-element array containing
3891 * {@code this}.
3892 *
3893 * @apiNote
3894 * The returned array includes only the nest members recorded in the {@code NestMembers}
3895 * attribute, and not any hidden classes that were added to the nest via
3896 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3897 * Lookup::defineHiddenClass}.
3898 *
3899 * @return an array of all classes and interfaces in the same nest as
3900 * this class or interface
3901 *
3902 * @since 11
3903 * @see #getNestHost()
3904 * @jvms 4.7.28 The {@code NestHost} Attribute
3905 * @jvms 4.7.29 The {@code NestMembers} Attribute
3906 */
3907 public Class<?>[] getNestMembers() {
3908 if (isPrimitive() || isArray()) {
3909 return new Class<?>[] { this };
3910 }
3911 Class<?>[] members = getNestMembers0();
3912 // Can't actually enable this due to bootstrapping issues
3913 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3914 return members;
3915 }
3916
3917 /**
3918 * Returns the descriptor string of the entity (class, interface, array class,
3919 * primitive type, or {@code void}) represented by this {@code Class} object.
3920 *
3921 * <p> If this {@code Class} object represents a class or interface,
3922 * not an array class, then:
3923 * <ul>
3924 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3925 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3926 * for the class or interface. Calling
3927 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3928 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3929 * describing this class or interface.
3930 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3931 * then the result is a string of the form:
3932 * <blockquote>
3933 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3934 * </blockquote>
3935 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3936 * encoded in internal form indicated by the {@code class} file passed to
3937 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3938 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3939 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3940 * The result string is not a type descriptor.
3941 * </ul>
3942 *
3943 * <p> If this {@code Class} object represents an array class, then
3944 * the result is a string consisting of one or more '{@code [}' characters
3945 * representing the depth of the array nesting, followed by the
3946 * descriptor string of the element type.
3947 * <ul>
3948 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3949 * or interface, then this array class can be described nominally.
3950 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3951 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3952 * describing this array class.
3953 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3954 * interface, then this array class cannot be described nominally.
3955 * The result string is not a type descriptor.
3956 * </ul>
3957 *
3958 * <p> If this {@code Class} object represents a primitive type or
3959 * {@code void}, then the result is a field descriptor string which
3960 * is a one-letter code corresponding to a primitive type or {@code void}
3961 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3962 *
3963 * @return the descriptor string for this {@code Class} object
3964 * @jvms 4.3.2 Field Descriptors
3965 * @since 12
3966 */
3967 @Override
3968 public String descriptorString() {
3969 if (isPrimitive())
3970 return Wrapper.forPrimitiveType(this).basicTypeString();
3971
3972 if (isArray()) {
3973 return "[".concat(componentType.descriptorString());
3974 } else if (isHidden()) {
3975 String name = getName();
3976 int index = name.indexOf('/');
3977 return new StringBuilder(name.length() + 2)
3978 .append('L')
3979 .append(name.substring(0, index).replace('.', '/'))
3980 .append('.')
3981 .append(name, index + 1, name.length())
3982 .append(';')
3983 .toString();
3984 } else {
3985 String name = getName().replace('.', '/');
3986 return StringConcatHelper.concat("L", name, ";");
3987 }
3988 }
3989
3990 /**
3991 * Returns the component type of this {@code Class}, if it describes
3992 * an array type, or {@code null} otherwise.
3993 *
3994 * @implSpec
3995 * Equivalent to {@link Class#getComponentType()}.
3996 *
3997 * @return a {@code Class} describing the component type, or {@code null}
3998 * if this {@code Class} does not describe an array type
3999 * @since 12
4000 */
4001 @Override
4002 public Class<?> componentType() {
4003 return getComponentType();
4004 }
4005
4006 /**
4007 * Returns a {@code Class} for an array type whose component type
4008 * is described by this {@linkplain Class}.
4009 *
4010 * @throws UnsupportedOperationException if this component type is {@linkplain
4011 * Void#TYPE void} or if the number of dimensions of the resulting array
4012 * type would exceed 255.
4013 * @return a {@code Class} describing the array type
4014 * @jvms 4.3.2 Field Descriptors
4015 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4016 * @since 12
4017 */
4018 @Override
4019 public Class<?> arrayType() {
4020 try {
4021 return Array.newInstance(this, 0).getClass();
4022 } catch (IllegalArgumentException iae) {
4023 throw new UnsupportedOperationException(iae);
4024 }
4025 }
4026
4027 /**
4028 * Returns a nominal descriptor for this instance, if one can be
4029 * constructed, or an empty {@link Optional} if one cannot be.
4030 *
4031 * @return An {@link Optional} containing the resulting nominal descriptor,
4032 * or an empty {@link Optional} if one cannot be constructed.
4033 * @since 12
4034 */
4035 @Override
4036 public Optional<ClassDesc> describeConstable() {
4037 Class<?> c = isArray() ? elementType() : this;
4038 return c.isHidden() ? Optional.empty()
4039 : Optional.of(ConstantUtils.classDesc(this));
4040 }
4041
4042 /**
4043 * Returns {@code true} if and only if the underlying class is a hidden class.
4044 *
4045 * @return {@code true} if and only if this class is a hidden class.
4046 *
4047 * @since 15
4048 * @see MethodHandles.Lookup#defineHiddenClass
4049 * @see Class##hiddenClasses Hidden Classes
4050 */
4051 @IntrinsicCandidate
4052 public native boolean isHidden();
4053
4054 /**
4055 * Returns an array containing {@code Class} objects representing the
4056 * direct subinterfaces or subclasses permitted to extend or
4057 * implement this class or interface if it is sealed. The order of such elements
4058 * is unspecified. The array is empty if this sealed class or interface has no
4059 * permitted subclass. If this {@code Class} object represents a primitive type,
4060 * {@code void}, an array type, or a class or interface that is not sealed,
4061 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4062 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4063 * returns a non-null value.
4064 *
4065 * For each class or interface {@code C} which is recorded as a permitted
4066 * direct subinterface or subclass of this class or interface,
4067 * this method attempts to obtain the {@code Class}
4068 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4069 * loader} of the current {@code Class} object).
4070 * The {@code Class} objects which can be obtained and which are direct
4071 * subinterfaces or subclasses of this class or interface,
4072 * are indicated by elements of the returned array. If a {@code Class} object
4073 * cannot be obtained, it is silently ignored, and not included in the result
4074 * array.
4075 *
4076 * @return an array of {@code Class} objects of the permitted subclasses of this class
4077 * or interface, or {@code null} if this class or interface is not sealed.
4078 *
4079 * @jls 8.1 Class Declarations
4080 * @jls 9.1 Interface Declarations
4081 * @since 17
4082 */
4083 public Class<?>[] getPermittedSubclasses() {
4084 Class<?>[] subClasses;
4085 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4086 return null;
4087 }
4088 if (subClasses.length > 0) {
4089 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4090 subClasses = Arrays.stream(subClasses)
4091 .filter(this::isDirectSubType)
4092 .toArray(s -> new Class<?>[s]);
4093 }
4094 }
4095 return subClasses;
4096 }
4097
4098 private boolean isDirectSubType(Class<?> c) {
4099 if (isInterface()) {
4100 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4101 if (i == this) {
4102 return true;
4103 }
4104 }
4105 } else {
4106 return c.getSuperclass() == this;
4107 }
4108 return false;
4109 }
4110
4111 /**
4112 * Returns {@code true} if and only if this {@code Class} object represents
4113 * a sealed class or interface. If this {@code Class} object represents a
4114 * primitive type, {@code void}, or an array type, this method returns
4115 * {@code false}. A sealed class or interface has (possibly zero) permitted
4116 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4117 * possibly empty value for a sealed class or interface.
4118 *
4119 * @return {@code true} if and only if this {@code Class} object represents
4120 * a sealed class or interface.
4121 *
4122 * @jls 8.1 Class Declarations
4123 * @jls 9.1 Interface Declarations
4124 * @since 17
4125 */
4126 public boolean isSealed() {
4127 if (isArray() || isPrimitive()) {
4128 return false;
4129 }
4130 return getPermittedSubclasses() != null;
4131 }
4132
4133 private native Class<?>[] getPermittedSubclasses0();
4134
4135 /*
4136 * Return the class's major and minor class file version packed into an int.
4137 * The high order 16 bits contain the class's minor version. The low order
4138 * 16 bits contain the class's major version.
4139 *
4140 * If the class is an array type then the class file version of its element
4141 * type is returned. If the class is a primitive type then the latest class
4142 * file major version is returned and zero is returned for the minor version.
4143 */
4144 int getClassFileVersion() {
4145 Class<?> c = isArray() ? elementType() : this;
4146 return c.getClassFileVersion0();
4147 }
4148
4149 private native int getClassFileVersion0();
4150
4151 /*
4152 * Return the access flags as they were in the class's bytecode, including
4153 * the original setting of ACC_SUPER.
4154 *
4155 * If the class is an array type then the access flags of the element type is
4156 * returned. If the class is a primitive then ACC_ABSTRACT | ACC_FINAL | ACC_PUBLIC.
4157 */
4158 private int getClassAccessFlagsRaw() {
4159 Class<?> c = isArray() ? elementType() : this;
4160 return c.getClassAccessFlagsRaw0();
4161 }
4162
4163 private native int getClassAccessFlagsRaw0();
4164
4165 // Support for "OLD" CDS workflow -- {
4166 private static final int RD_PUBLIC_METHODS = (1 << 0);
4167 private static final int RD_PUBLIC_FIELDS = (1 << 1);
4168 private static final int RD_DECLARED_CTORS = (1 << 2);
4169 private static final int RD_PUBLIC_CTORS = (1 << 3);
4170 private static final int RD_DECLARED_METHODS = (1 << 4);
4171 private static final int RD_DECLARED_PUBLIC_METHODS = (1 << 5);
4172 private static final int RD_DECLARED_FIELDS = (1 << 6);
4173 private static final int RD_DECLARED_PUBLIC_FIELDS = (1 << 7);
4174 private static final int RD_DECLARED_INTERFACES = (1 << 8);
4175 private static final int RD_DECLARED_SIMPLE_NAME = (1 << 9);
4176 private static final int RD_DECLARED_CANONICAL_NAME = (1 << 10);
4177 private static final int CLS_NAME = (1 << 10);
4178
4179
4180 private int encodeReflectionData() {
4181 int flags = CLS_NAME;
4182 if (reflectionData != null) {
4183 flags = (reflectionData.publicMethods != null ? RD_PUBLIC_METHODS : 0) |
4184 (reflectionData.publicFields != null ? RD_PUBLIC_FIELDS : 0) |
4185 (reflectionData.declaredConstructors != null ? RD_DECLARED_CTORS : 0) |
4186 (reflectionData.publicConstructors != null ? RD_PUBLIC_CTORS : 0) |
4187 (reflectionData.declaredMethods != null ? RD_DECLARED_METHODS : 0) |
4188 (reflectionData.declaredPublicMethods != null ? RD_DECLARED_PUBLIC_METHODS : 0) |
4189 (reflectionData.declaredFields != null ? RD_DECLARED_FIELDS : 0) |
4190 (reflectionData.declaredPublicFields != null ? RD_DECLARED_PUBLIC_FIELDS : 0) |
4191 (reflectionData.interfaces != null ? RD_DECLARED_INTERFACES : 0) |
4192 (reflectionData.simpleName != null ? RD_DECLARED_SIMPLE_NAME : 0) |
4193 (reflectionData.canonicalName != null ? RD_DECLARED_CANONICAL_NAME : 0);
4194 }
4195 return flags;
4196 }
4197 private void generateReflectionData(int flags) {
4198 if ((flags & CLS_NAME ) != 0) { getName(); } // String name
4199 if ((flags & RD_PUBLIC_METHODS ) != 0) { privateGetPublicMethods(); } // Method[] publicMethods;
4200 if ((flags & RD_PUBLIC_FIELDS ) != 0) { privateGetPublicFields(); } // Field[] publicFields;
4201 if ((flags & RD_DECLARED_CTORS ) != 0) { privateGetDeclaredConstructors(false); } // Constructor<T>[] declaredConstructors;
4202 if ((flags & RD_PUBLIC_CTORS ) != 0) { privateGetDeclaredConstructors(true); } // Constructor<T>[] publicConstructors;
4203 if ((flags & RD_DECLARED_METHODS ) != 0) { privateGetDeclaredMethods(false); } // Method[] declaredMethods;
4204 if ((flags & RD_DECLARED_PUBLIC_METHODS) != 0) { privateGetDeclaredMethods(true); } // Method[] declaredPublicMethods;
4205 if ((flags & RD_DECLARED_FIELDS ) != 0) { privateGetDeclaredFields(false); } // Field[] declaredFields;
4206 if ((flags & RD_DECLARED_PUBLIC_FIELDS ) != 0) { privateGetDeclaredFields(true); } // Field[] declaredPublicFields;
4207 if ((flags & RD_DECLARED_INTERFACES ) != 0) { getInterfaces(false); } // Class<?>[] interfaces;
4208 if ((flags & RD_DECLARED_SIMPLE_NAME ) != 0) { getSimpleName(); } // String simpleName;
4209 if ((flags & RD_DECLARED_CANONICAL_NAME) != 0) { getCanonicalName(); } // String canonicalName;
4210 }
4211
4212 // -- }
4213 }