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 AccessFlag.maskToAccessFlags((location == AccessFlag.Location.CLASS) ?
1410 getClassAccessFlagsRaw() :
1411 getModifiers(),
1412 location);
1413 }
1414
1415 /**
1416 * Gets the signers of this class.
1417 *
1418 * @return the signers of this class, or null if there are no signers. In
1419 * particular, this method returns null if this {@code Class} object represents
1420 * a primitive type or void.
1421 * @since 1.1
1422 */
1423 public Object[] getSigners() {
1424 var signers = this.signers;
1425 return signers == null ? null : signers.clone();
1426 }
1427
1428 /**
1429 * Set the signers of this class.
1430 */
1431 void setSigners(Object[] signers) {
1432 if (!isPrimitive() && !isArray()) {
1433 this.signers = signers;
1434 }
1435 }
1436
1437 /**
1438 * If this {@code Class} object represents a local or anonymous
1439 * class within a method, returns a {@link
1440 * java.lang.reflect.Method Method} object representing the
1441 * immediately enclosing method of the underlying class. Returns
1442 * {@code null} otherwise.
1443 *
1444 * In particular, this method returns {@code null} if the underlying
1445 * class is a local or anonymous class immediately enclosed by a class or
1446 * interface declaration, instance initializer or static initializer.
1447 *
1448 * @return the immediately enclosing method of the underlying class, if
1449 * that class is a local or anonymous class; otherwise {@code null}.
1450 *
1451 * @since 1.5
1452 */
1453 public Method getEnclosingMethod() {
1454 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1455
1456 if (enclosingInfo == null)
1457 return null;
1458 else {
1459 if (!enclosingInfo.isMethod())
1460 return null;
1461
1462 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1463 getFactory());
1464 Class<?> returnType = toClass(typeInfo.getReturnType());
1465 Type [] parameterTypes = typeInfo.getParameterTypes();
1466 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1467
1468 // Convert Types to Classes; returned types *should*
1469 // be class objects since the methodDescriptor's used
1470 // don't have generics information
1471 for(int i = 0; i < parameterClasses.length; i++)
1472 parameterClasses[i] = toClass(parameterTypes[i]);
1473
1474 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1475 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1476
1477 /*
1478 * Loop over all declared methods; match method name,
1479 * number of and type of parameters, *and* return
1480 * type. Matching return type is also necessary
1481 * because of covariant returns, etc.
1482 */
1483 ReflectionFactory fact = getReflectionFactory();
1484 for (Method m : candidates) {
1485 if (m.getName().equals(enclosingInfo.getName()) &&
1486 arrayContentsEq(parameterClasses,
1487 fact.getExecutableSharedParameterTypes(m))) {
1488 // finally, check return type
1489 if (m.getReturnType().equals(returnType)) {
1490 return fact.copyMethod(m);
1491 }
1492 }
1493 }
1494
1495 throw new InternalError("Enclosing method not found");
1496 }
1497 }
1498
1499 private native Object[] getEnclosingMethod0();
1500
1501 private EnclosingMethodInfo getEnclosingMethodInfo() {
1502 Object[] enclosingInfo = getEnclosingMethod0();
1503 if (enclosingInfo == null)
1504 return null;
1505 else {
1506 return new EnclosingMethodInfo(enclosingInfo);
1507 }
1508 }
1509
1510 private static final class EnclosingMethodInfo {
1511 private final Class<?> enclosingClass;
1512 private final String name;
1513 private final String descriptor;
1514
1515 static void validate(Object[] enclosingInfo) {
1516 if (enclosingInfo.length != 3)
1517 throw new InternalError("Malformed enclosing method information");
1518 try {
1519 // The array is expected to have three elements:
1520
1521 // the immediately enclosing class
1522 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1523 assert(enclosingClass != null);
1524
1525 // the immediately enclosing method or constructor's
1526 // name (can be null).
1527 String name = (String)enclosingInfo[1];
1528
1529 // the immediately enclosing method or constructor's
1530 // descriptor (null iff name is).
1531 String descriptor = (String)enclosingInfo[2];
1532 assert((name != null && descriptor != null) || name == descriptor);
1533 } catch (ClassCastException cce) {
1534 throw new InternalError("Invalid type in enclosing method information", cce);
1535 }
1536 }
1537
1538 EnclosingMethodInfo(Object[] enclosingInfo) {
1539 validate(enclosingInfo);
1540 this.enclosingClass = (Class<?>)enclosingInfo[0];
1541 this.name = (String)enclosingInfo[1];
1542 this.descriptor = (String)enclosingInfo[2];
1543 }
1544
1545 boolean isPartial() {
1546 return enclosingClass == null || name == null || descriptor == null;
1547 }
1548
1549 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1550
1551 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1552
1553 Class<?> getEnclosingClass() { return enclosingClass; }
1554
1555 String getName() { return name; }
1556
1557 String getDescriptor() { return descriptor; }
1558
1559 }
1560
1561 private static Class<?> toClass(Type o) {
1562 if (o instanceof GenericArrayType gat)
1563 return toClass(gat.getGenericComponentType()).arrayType();
1564 return (Class<?>)o;
1565 }
1566
1567 /**
1568 * If this {@code Class} object represents a local or anonymous
1569 * class within a constructor, returns a {@link
1570 * java.lang.reflect.Constructor Constructor} object representing
1571 * the immediately enclosing constructor of the underlying
1572 * class. Returns {@code null} otherwise. In particular, this
1573 * method returns {@code null} if the underlying class is a local
1574 * or anonymous class immediately enclosed by a class or
1575 * interface declaration, instance initializer or static initializer.
1576 *
1577 * @return the immediately enclosing constructor of the underlying class, if
1578 * that class is a local or anonymous class; otherwise {@code null}.
1579 *
1580 * @since 1.5
1581 */
1582 public Constructor<?> getEnclosingConstructor() {
1583 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1584
1585 if (enclosingInfo == null)
1586 return null;
1587 else {
1588 if (!enclosingInfo.isConstructor())
1589 return null;
1590
1591 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1592 getFactory());
1593 Type [] parameterTypes = typeInfo.getParameterTypes();
1594 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1595
1596 // Convert Types to Classes; returned types *should*
1597 // be class objects since the methodDescriptor's used
1598 // don't have generics information
1599 for (int i = 0; i < parameterClasses.length; i++)
1600 parameterClasses[i] = toClass(parameterTypes[i]);
1601
1602
1603 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1604 Constructor<?>[] candidates = enclosingCandidate
1605 .privateGetDeclaredConstructors(false);
1606 /*
1607 * Loop over all declared constructors; match number
1608 * of and type of parameters.
1609 */
1610 ReflectionFactory fact = getReflectionFactory();
1611 for (Constructor<?> c : candidates) {
1612 if (arrayContentsEq(parameterClasses,
1613 fact.getExecutableSharedParameterTypes(c))) {
1614 return fact.copyConstructor(c);
1615 }
1616 }
1617
1618 throw new InternalError("Enclosing constructor not found");
1619 }
1620 }
1621
1622
1623 /**
1624 * If the class or interface represented by this {@code Class} object
1625 * is a member of another class, returns the {@code Class} object
1626 * representing the class in which it was declared. This method returns
1627 * null if this class or interface is not a member of any other class. If
1628 * this {@code Class} object represents an array class, a primitive
1629 * type, or void, then this method returns null.
1630 *
1631 * @return the declaring class for this class
1632 * @since 1.1
1633 */
1634 public Class<?> getDeclaringClass() {
1635 return getDeclaringClass0();
1636 }
1637
1638 private native Class<?> getDeclaringClass0();
1639
1640
1641 /**
1642 * Returns the immediately enclosing class of the underlying
1643 * class. If the underlying class is a top level class this
1644 * method returns {@code null}.
1645 * @return the immediately enclosing class of the underlying class
1646 * @since 1.5
1647 */
1648 public Class<?> getEnclosingClass() {
1649 // There are five kinds of classes (or interfaces):
1650 // a) Top level classes
1651 // b) Nested classes (static member classes)
1652 // c) Inner classes (non-static member classes)
1653 // d) Local classes (named classes declared within a method)
1654 // e) Anonymous classes
1655
1656
1657 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1658 // attribute if and only if it is a local class or an
1659 // anonymous class.
1660 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1661 Class<?> enclosingCandidate;
1662
1663 if (enclosingInfo == null) {
1664 // This is a top level or a nested class or an inner class (a, b, or c)
1665 enclosingCandidate = getDeclaringClass0();
1666 } else {
1667 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1668 // This is a local class or an anonymous class (d or e)
1669 if (enclosingClass == this || enclosingClass == null)
1670 throw new InternalError("Malformed enclosing method information");
1671 else
1672 enclosingCandidate = enclosingClass;
1673 }
1674 return enclosingCandidate;
1675 }
1676
1677 /**
1678 * Returns the simple name of the underlying class as given in the
1679 * source code. An empty string is returned if the underlying class is
1680 * {@linkplain #isAnonymousClass() anonymous}.
1681 * A {@linkplain #isSynthetic() synthetic class}, one not present
1682 * in source code, can have a non-empty name including special
1683 * characters, such as "{@code $}".
1684 *
1685 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1686 * component type with "[]" appended. In particular the simple
1687 * name of an array class whose component type is anonymous is "[]".
1688 *
1689 * @return the simple name of the underlying class
1690 * @since 1.5
1691 */
1692 public String getSimpleName() {
1693 ReflectionData<T> rd = reflectionData();
1694 String simpleName = rd.simpleName;
1695 if (simpleName == null) {
1696 rd.simpleName = simpleName = getSimpleName0();
1697 }
1698 return simpleName;
1699 }
1700
1701 private String getSimpleName0() {
1702 if (isArray()) {
1703 return getComponentType().getSimpleName().concat("[]");
1704 }
1705 String simpleName = getSimpleBinaryName();
1706 if (simpleName == null) { // top level class
1707 simpleName = getName();
1708 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1709 }
1710 return simpleName;
1711 }
1712
1713 /**
1714 * Return an informative string for the name of this class or interface.
1715 *
1716 * @return an informative string for the name of this class or interface
1717 * @since 1.8
1718 */
1719 public String getTypeName() {
1720 if (isArray()) {
1721 try {
1722 Class<?> cl = this;
1723 int dimensions = 0;
1724 do {
1725 dimensions++;
1726 cl = cl.getComponentType();
1727 } while (cl.isArray());
1728 return cl.getName().concat("[]".repeat(dimensions));
1729 } catch (Throwable e) { /*FALLTHRU*/ }
1730 }
1731 return getName();
1732 }
1733
1734 /**
1735 * Returns the canonical name of the underlying class as
1736 * defined by <cite>The Java Language Specification</cite>.
1737 * Returns {@code null} if the underlying class does not have a canonical
1738 * name. Classes without canonical names include:
1739 * <ul>
1740 * <li>a {@linkplain #isLocalClass() local class}
1741 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1742 * <li>a {@linkplain #isHidden() hidden class}
1743 * <li>an array whose component type does not have a canonical name</li>
1744 * </ul>
1745 *
1746 * The canonical name for a primitive class is the keyword for the
1747 * corresponding primitive type ({@code byte}, {@code short},
1748 * {@code char}, {@code int}, and so on).
1749 *
1750 * <p>An array type has a canonical name if and only if its
1751 * component type has a canonical name. When an array type has a
1752 * canonical name, it is equal to the canonical name of the
1753 * component type followed by "{@code []}".
1754 *
1755 * @return the canonical name of the underlying class if it exists, and
1756 * {@code null} otherwise.
1757 * @jls 6.7 Fully Qualified Names and Canonical Names
1758 * @since 1.5
1759 */
1760 public String getCanonicalName() {
1761 ReflectionData<T> rd = reflectionData();
1762 String canonicalName = rd.canonicalName;
1763 if (canonicalName == null) {
1764 rd.canonicalName = canonicalName = getCanonicalName0();
1765 }
1766 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1767 }
1768
1769 private String getCanonicalName0() {
1770 if (isArray()) {
1771 String canonicalName = getComponentType().getCanonicalName();
1772 if (canonicalName != null)
1773 return canonicalName.concat("[]");
1774 else
1775 return ReflectionData.NULL_SENTINEL;
1776 }
1777 if (isHidden() || isLocalOrAnonymousClass())
1778 return ReflectionData.NULL_SENTINEL;
1779 Class<?> enclosingClass = getEnclosingClass();
1780 if (enclosingClass == null) { // top level class
1781 return getName();
1782 } else {
1783 String enclosingName = enclosingClass.getCanonicalName();
1784 if (enclosingName == null)
1785 return ReflectionData.NULL_SENTINEL;
1786 String simpleName = getSimpleName();
1787 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1788 .append(enclosingName)
1789 .append('.')
1790 .append(simpleName)
1791 .toString();
1792 }
1793 }
1794
1795 /**
1796 * Returns {@code true} if and only if the underlying class
1797 * is an anonymous class.
1798 *
1799 * @apiNote
1800 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1801 *
1802 * @return {@code true} if and only if this class is an anonymous class.
1803 * @since 1.5
1804 * @jls 15.9.5 Anonymous Class Declarations
1805 */
1806 public boolean isAnonymousClass() {
1807 return !isArray() && isLocalOrAnonymousClass() &&
1808 getSimpleBinaryName0() == null;
1809 }
1810
1811 /**
1812 * Returns {@code true} if and only if the underlying class
1813 * is a local class.
1814 *
1815 * @return {@code true} if and only if this class is a local class.
1816 * @since 1.5
1817 * @jls 14.3 Local Class and Interface Declarations
1818 */
1819 public boolean isLocalClass() {
1820 return isLocalOrAnonymousClass() &&
1821 (isArray() || getSimpleBinaryName0() != null);
1822 }
1823
1824 /**
1825 * Returns {@code true} if and only if the underlying class
1826 * is a member class.
1827 *
1828 * @return {@code true} if and only if this class is a member class.
1829 * @since 1.5
1830 * @jls 8.5 Member Class and Interface Declarations
1831 */
1832 public boolean isMemberClass() {
1833 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1834 }
1835
1836 /**
1837 * Returns the "simple binary name" of the underlying class, i.e.,
1838 * the binary name without the leading enclosing class name.
1839 * Returns {@code null} if the underlying class is a top level
1840 * class.
1841 */
1842 private String getSimpleBinaryName() {
1843 if (isTopLevelClass())
1844 return null;
1845 String name = getSimpleBinaryName0();
1846 if (name == null) // anonymous class
1847 return "";
1848 return name;
1849 }
1850
1851 private native String getSimpleBinaryName0();
1852
1853 /**
1854 * Returns {@code true} if this is a top level class. Returns {@code false}
1855 * otherwise.
1856 */
1857 private boolean isTopLevelClass() {
1858 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1859 }
1860
1861 /**
1862 * Returns {@code true} if this is a local class or an anonymous
1863 * class. Returns {@code false} otherwise.
1864 */
1865 private boolean isLocalOrAnonymousClass() {
1866 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1867 // attribute if and only if it is a local class or an
1868 // anonymous class.
1869 return hasEnclosingMethodInfo();
1870 }
1871
1872 private boolean hasEnclosingMethodInfo() {
1873 Object[] enclosingInfo = getEnclosingMethod0();
1874 if (enclosingInfo != null) {
1875 EnclosingMethodInfo.validate(enclosingInfo);
1876 return true;
1877 }
1878 return false;
1879 }
1880
1881 /**
1882 * Returns an array containing {@code Class} objects representing all
1883 * the public classes and interfaces that are members of the class
1884 * represented by this {@code Class} object. This includes public
1885 * class and interface members inherited from superclasses and public class
1886 * and interface members declared by the class. This method returns an
1887 * array of length 0 if this {@code Class} object has no public member
1888 * classes or interfaces. This method also returns an array of length 0 if
1889 * this {@code Class} object represents a primitive type, an array
1890 * class, or void.
1891 *
1892 * @return the array of {@code Class} objects representing the public
1893 * members of this class
1894 * @since 1.1
1895 */
1896 public Class<?>[] getClasses() {
1897 List<Class<?>> list = new ArrayList<>();
1898 Class<?> currentClass = Class.this;
1899 while (currentClass != null) {
1900 for (Class<?> m : currentClass.getDeclaredClasses()) {
1901 if (Modifier.isPublic(m.getModifiers())) {
1902 list.add(m);
1903 }
1904 }
1905 currentClass = currentClass.getSuperclass();
1906 }
1907 return list.toArray(new Class<?>[0]);
1908 }
1909
1910
1911 /**
1912 * Returns an array containing {@code Field} objects reflecting all
1913 * the accessible public fields of the class or interface represented by
1914 * this {@code Class} object.
1915 *
1916 * <p> If this {@code Class} object represents a class or interface with
1917 * no accessible public fields, then this method returns an array of length
1918 * 0.
1919 *
1920 * <p> If this {@code Class} object represents a class, then this method
1921 * returns the public fields of the class and of all its superclasses and
1922 * superinterfaces.
1923 *
1924 * <p> If this {@code Class} object represents an interface, then this
1925 * method returns the fields of the interface and of all its
1926 * superinterfaces.
1927 *
1928 * <p> If this {@code Class} object represents an array type, a primitive
1929 * type, or void, then this method returns an array of length 0.
1930 *
1931 * <p> The elements in the returned array are not sorted and are not in any
1932 * particular order.
1933 *
1934 * @return the array of {@code Field} objects representing the
1935 * public fields
1936 *
1937 * @since 1.1
1938 * @jls 8.2 Class Members
1939 * @jls 8.3 Field Declarations
1940 */
1941 public Field[] getFields() {
1942 return copyFields(privateGetPublicFields());
1943 }
1944
1945
1946 /**
1947 * Returns an array containing {@code Method} objects reflecting all the
1948 * public methods of the class or interface represented by this {@code
1949 * Class} object, including those declared by the class or interface and
1950 * those inherited from superclasses and superinterfaces.
1951 *
1952 * <p> If this {@code Class} object represents an array type, then the
1953 * returned array has a {@code Method} object for each of the public
1954 * methods inherited by the array type from {@code Object}. It does not
1955 * contain a {@code Method} object for {@code clone()}.
1956 *
1957 * <p> If this {@code Class} object represents an interface then the
1958 * returned array does not contain any implicitly declared methods from
1959 * {@code Object}. Therefore, if no methods are explicitly declared in
1960 * this interface or any of its superinterfaces then the returned array
1961 * has length 0. (Note that a {@code Class} object which represents a class
1962 * always has public methods, inherited from {@code Object}.)
1963 *
1964 * <p> The returned array never contains methods with names {@value
1965 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1966 *
1967 * <p> The elements in the returned array are not sorted and are not in any
1968 * particular order.
1969 *
1970 * <p> Generally, the result is computed as with the following 4 step algorithm.
1971 * Let C be the class or interface represented by this {@code Class} object:
1972 * <ol>
1973 * <li> A union of methods is composed of:
1974 * <ol type="a">
1975 * <li> C's declared public instance and static methods as returned by
1976 * {@link #getDeclaredMethods()} and filtered to include only public
1977 * methods.</li>
1978 * <li> If C is a class other than {@code Object}, then include the result
1979 * of invoking this algorithm recursively on the superclass of C.</li>
1980 * <li> Include the results of invoking this algorithm recursively on all
1981 * direct superinterfaces of C, but include only instance methods.</li>
1982 * </ol></li>
1983 * <li> Union from step 1 is partitioned into subsets of methods with same
1984 * signature (name, parameter types) and return type.</li>
1985 * <li> Within each such subset only the most specific methods are selected.
1986 * Let method M be a method from a set of methods with same signature
1987 * and return type. M is most specific if there is no such method
1988 * N != M from the same set, such that N is more specific than M.
1989 * N is more specific than M if:
1990 * <ol type="a">
1991 * <li> N is declared by a class and M is declared by an interface; or</li>
1992 * <li> N and M are both declared by classes or both by interfaces and
1993 * N's declaring type is the same as or a subtype of M's declaring type
1994 * (clearly, if M's and N's declaring types are the same type, then
1995 * M and N are the same method).</li>
1996 * </ol></li>
1997 * <li> The result of this algorithm is the union of all selected methods from
1998 * step 3.</li>
1999 * </ol>
2000 *
2001 * @apiNote There may be more than one method with a particular name
2002 * and parameter types in a class because while the Java language forbids a
2003 * class to declare multiple methods with the same signature but different
2004 * return types, the Java virtual machine does not. This
2005 * increased flexibility in the virtual machine can be used to
2006 * implement various language features. For example, covariant
2007 * returns can be implemented with {@linkplain
2008 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2009 * method and the overriding method would have the same
2010 * signature but different return types.
2011 *
2012 * @return the array of {@code Method} objects representing the
2013 * public methods of this class
2014 *
2015 * @jls 8.2 Class Members
2016 * @jls 8.4 Method Declarations
2017 * @since 1.1
2018 */
2019 public Method[] getMethods() {
2020 return copyMethods(privateGetPublicMethods());
2021 }
2022
2023
2024 /**
2025 * Returns an array containing {@code Constructor} objects reflecting
2026 * all the public constructors of the class represented by this
2027 * {@code Class} object. An array of length 0 is returned if the
2028 * class has no public constructors, or if the class is an array class, or
2029 * if the class reflects a primitive type or void.
2030 *
2031 * @apiNote
2032 * While this method returns an array of {@code
2033 * Constructor<T>} objects (that is an array of constructors from
2034 * this class), the return type of this method is {@code
2035 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2036 * might be expected. This less informative return type is
2037 * necessary since after being returned from this method, the
2038 * array could be modified to hold {@code Constructor} objects for
2039 * different classes, which would violate the type guarantees of
2040 * {@code Constructor<T>[]}.
2041 *
2042 * @return the array of {@code Constructor} objects representing the
2043 * public constructors of this class
2044 *
2045 * @see #getDeclaredConstructors()
2046 * @since 1.1
2047 */
2048 public Constructor<?>[] getConstructors() {
2049 return copyConstructors(privateGetDeclaredConstructors(true));
2050 }
2051
2052
2053 /**
2054 * Returns a {@code Field} object that reflects the specified public member
2055 * field of the class or interface represented by this {@code Class}
2056 * object. The {@code name} parameter is a {@code String} specifying the
2057 * simple name of the desired field.
2058 *
2059 * <p> The field to be reflected is determined by the algorithm that
2060 * follows. Let C be the class or interface represented by this {@code Class} object:
2061 *
2062 * <OL>
2063 * <LI> If C declares a public field with the name specified, that is the
2064 * field to be reflected.</LI>
2065 * <LI> If no field was found in step 1 above, this algorithm is applied
2066 * recursively to each direct superinterface of C. The direct
2067 * superinterfaces are searched in the order they were declared.</LI>
2068 * <LI> If no field was found in steps 1 and 2 above, and C has a
2069 * superclass S, then this algorithm is invoked recursively upon S.
2070 * If C has no superclass, then a {@code NoSuchFieldException}
2071 * is thrown.</LI>
2072 * </OL>
2073 *
2074 * <p> If this {@code Class} object represents an array type, then this
2075 * method does not find the {@code length} field of the array type.
2076 *
2077 * @param name the field name
2078 * @return the {@code Field} object of this class specified by
2079 * {@code name}
2080 * @throws NoSuchFieldException if a field with the specified name is
2081 * not found.
2082 * @throws NullPointerException if {@code name} is {@code null}
2083 *
2084 * @since 1.1
2085 * @jls 8.2 Class Members
2086 * @jls 8.3 Field Declarations
2087 */
2088 public Field getField(String name) throws NoSuchFieldException {
2089 Objects.requireNonNull(name);
2090 Field field = getField0(name);
2091 if (field == null) {
2092 throw new NoSuchFieldException(name);
2093 }
2094 return getReflectionFactory().copyField(field);
2095 }
2096
2097
2098 /**
2099 * Returns a {@code Method} object that reflects the specified public
2100 * member method of the class or interface represented by this
2101 * {@code Class} object. The {@code name} parameter is a
2102 * {@code String} specifying the simple name of the desired method. The
2103 * {@code parameterTypes} parameter is an array of {@code Class}
2104 * objects that identify the method's formal parameter types, in declared
2105 * order. If {@code parameterTypes} is {@code null}, it is
2106 * treated as if it were an empty array.
2107 *
2108 * <p> If this {@code Class} object represents an array type, then this
2109 * method finds any public method inherited by the array type from
2110 * {@code Object} except method {@code clone()}.
2111 *
2112 * <p> If this {@code Class} object represents an interface then this
2113 * method does not find any implicitly declared method from
2114 * {@code Object}. Therefore, if no methods are explicitly declared in
2115 * this interface or any of its superinterfaces, then this method does not
2116 * find any method.
2117 *
2118 * <p> This method does not find any method with name {@value
2119 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2120 *
2121 * <p> Generally, the method to be reflected is determined by the 4 step
2122 * algorithm that follows.
2123 * Let C be the class or interface represented by this {@code Class} object:
2124 * <ol>
2125 * <li> A union of methods is composed of:
2126 * <ol type="a">
2127 * <li> C's declared public instance and static methods as returned by
2128 * {@link #getDeclaredMethods()} and filtered to include only public
2129 * methods that match given {@code name} and {@code parameterTypes}</li>
2130 * <li> If C is a class other than {@code Object}, then include the result
2131 * of invoking this algorithm recursively on the superclass of C.</li>
2132 * <li> Include the results of invoking this algorithm recursively on all
2133 * direct superinterfaces of C, but include only instance methods.</li>
2134 * </ol></li>
2135 * <li> This union is partitioned into subsets of methods with same
2136 * return type (the selection of methods from step 1 also guarantees that
2137 * they have the same method name and parameter types).</li>
2138 * <li> Within each such subset only the most specific methods are selected.
2139 * Let method M be a method from a set of methods with same VM
2140 * signature (return type, name, parameter types).
2141 * M is most specific if there is no such method N != M from the same
2142 * set, such that N is more specific than M. N is more specific than M
2143 * if:
2144 * <ol type="a">
2145 * <li> N is declared by a class and M is declared by an interface; or</li>
2146 * <li> N and M are both declared by classes or both by interfaces and
2147 * N's declaring type is the same as or a subtype of M's declaring type
2148 * (clearly, if M's and N's declaring types are the same type, then
2149 * M and N are the same method).</li>
2150 * </ol></li>
2151 * <li> The result of this algorithm is chosen arbitrarily from the methods
2152 * with most specific return type among all selected methods from step 3.
2153 * Let R be a return type of a method M from the set of all selected methods
2154 * from step 3. M is a method with most specific return type if there is
2155 * no such method N != M from the same set, having return type S != R,
2156 * such that S is a subtype of R as determined by
2157 * R.class.{@link #isAssignableFrom}(S.class).
2158 * </ol>
2159 *
2160 * @apiNote There may be more than one method with matching name and
2161 * parameter types in a class because while the Java language forbids a
2162 * class to declare multiple methods with the same signature but different
2163 * return types, the Java virtual machine does not. This
2164 * increased flexibility in the virtual machine can be used to
2165 * implement various language features. For example, covariant
2166 * returns can be implemented with {@linkplain
2167 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2168 * method and the overriding method would have the same
2169 * signature but different return types. This method would return the
2170 * overriding method as it would have a more specific return type.
2171 *
2172 * @param name the name of the method
2173 * @param parameterTypes the list of parameters
2174 * @return the {@code Method} object that matches the specified
2175 * {@code name} and {@code parameterTypes}
2176 * @throws NoSuchMethodException if a matching method is not found
2177 * or if the name is {@value ConstantDescs#INIT_NAME} or
2178 * {@value ConstantDescs#CLASS_INIT_NAME}.
2179 * @throws NullPointerException if {@code name} is {@code null}
2180 *
2181 * @jls 8.2 Class Members
2182 * @jls 8.4 Method Declarations
2183 * @since 1.1
2184 */
2185 public Method getMethod(String name, Class<?>... parameterTypes)
2186 throws NoSuchMethodException {
2187 Objects.requireNonNull(name);
2188 Method method = getMethod0(name, parameterTypes);
2189 if (method == null) {
2190 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2191 }
2192 return getReflectionFactory().copyMethod(method);
2193 }
2194
2195 /**
2196 * Returns a {@code Constructor} object that reflects the specified
2197 * public constructor of the class represented by this {@code Class}
2198 * object. The {@code parameterTypes} parameter is an array of
2199 * {@code Class} objects that identify the constructor's formal
2200 * parameter types, in declared order.
2201 *
2202 * If this {@code Class} object represents an inner class
2203 * declared in a non-static context, the formal parameter types
2204 * include the explicit enclosing instance as the first parameter.
2205 *
2206 * <p> The constructor to reflect is the public constructor of the class
2207 * represented by this {@code Class} object whose formal parameter
2208 * types match those specified by {@code parameterTypes}.
2209 *
2210 * @param parameterTypes the parameter array
2211 * @return the {@code Constructor} object of the public constructor that
2212 * matches the specified {@code parameterTypes}
2213 * @throws NoSuchMethodException if a matching constructor is not found,
2214 * including when this {@code Class} object represents
2215 * an interface, a primitive type, an array class, or void.
2216 *
2217 * @see #getDeclaredConstructor(Class[])
2218 * @since 1.1
2219 */
2220 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2221 throws NoSuchMethodException {
2222 return getReflectionFactory().copyConstructor(
2223 getConstructor0(parameterTypes, Member.PUBLIC));
2224 }
2225
2226
2227 /**
2228 * Returns an array of {@code Class} objects reflecting all the
2229 * classes and interfaces declared as members of the class represented by
2230 * this {@code Class} object. This includes public, protected, default
2231 * (package) access, and private classes and interfaces declared by the
2232 * class, but excludes inherited classes and interfaces. This method
2233 * returns an array of length 0 if the class declares no classes or
2234 * interfaces as members, or if this {@code Class} object represents a
2235 * primitive type, an array class, or void.
2236 *
2237 * @return the array of {@code Class} objects representing all the
2238 * declared members of this class
2239 *
2240 * @since 1.1
2241 * @jls 8.5 Member Class and Interface Declarations
2242 */
2243 public Class<?>[] getDeclaredClasses() {
2244 return getDeclaredClasses0();
2245 }
2246
2247
2248 /**
2249 * Returns an array of {@code Field} objects reflecting all the fields
2250 * declared by the class or interface represented by this
2251 * {@code Class} object. This includes public, protected, default
2252 * (package) access, and private fields, but excludes inherited fields.
2253 *
2254 * <p> If this {@code Class} object represents a class or interface with no
2255 * declared fields, then this method returns an array of length 0.
2256 *
2257 * <p> If this {@code Class} object represents an array type, a primitive
2258 * type, or void, then this method returns an array of length 0.
2259 *
2260 * <p> The elements in the returned array are not sorted and are not in any
2261 * particular order.
2262 *
2263 * @return the array of {@code Field} objects representing all the
2264 * declared fields of this class
2265 *
2266 * @since 1.1
2267 * @jls 8.2 Class Members
2268 * @jls 8.3 Field Declarations
2269 */
2270 public Field[] getDeclaredFields() {
2271 return copyFields(privateGetDeclaredFields(false));
2272 }
2273
2274 /**
2275 * Returns an array of {@code RecordComponent} objects representing all the
2276 * record components of this record class, or {@code null} if this class is
2277 * not a record class.
2278 *
2279 * <p> The components are returned in the same order that they are declared
2280 * in the record header. The array is empty if this record class has no
2281 * components. If the class is not a record class, that is {@link
2282 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2283 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2284 * returns a non-null value.
2285 *
2286 * @apiNote
2287 * <p> The following method can be used to find the record canonical constructor:
2288 *
2289 * {@snippet lang="java" :
2290 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2291 * throws NoSuchMethodException {
2292 * Class<?>[] paramTypes =
2293 * Arrays.stream(cls.getRecordComponents())
2294 * .map(RecordComponent::getType)
2295 * .toArray(Class<?>[]::new);
2296 * return cls.getDeclaredConstructor(paramTypes);
2297 * }}
2298 *
2299 * @return An array of {@code RecordComponent} objects representing all the
2300 * record components of this record class, or {@code null} if this
2301 * class is not a record class
2302 *
2303 * @jls 8.10 Record Classes
2304 * @since 16
2305 */
2306 public RecordComponent[] getRecordComponents() {
2307 if (!isRecord()) {
2308 return null;
2309 }
2310 return getRecordComponents0();
2311 }
2312
2313 /**
2314 * Returns an array containing {@code Method} objects reflecting all the
2315 * declared methods of the class or interface represented by this {@code
2316 * Class} object, including public, protected, default (package)
2317 * access, and private methods, but excluding inherited methods.
2318 * The declared methods may include methods <em>not</em> in the
2319 * source of the class or interface, including {@linkplain
2320 * Method#isBridge bridge methods} and other {@linkplain
2321 * Executable#isSynthetic synthetic} methods added by compilers.
2322 *
2323 * <p> If this {@code Class} object represents a class or interface that
2324 * has multiple declared methods with the same name and parameter types,
2325 * but different return types, then the returned array has a {@code Method}
2326 * object for each such method.
2327 *
2328 * <p> If this {@code Class} object represents a class or interface that
2329 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2330 * then the returned array does <em>not</em> have a corresponding {@code
2331 * Method} object.
2332 *
2333 * <p> If this {@code Class} object represents a class or interface with no
2334 * declared methods, then the returned array has length 0.
2335 *
2336 * <p> If this {@code Class} object represents an array type, a primitive
2337 * type, or void, then the returned array has length 0.
2338 *
2339 * <p> The elements in the returned array are not sorted and are not in any
2340 * particular order.
2341 *
2342 * @return the array of {@code Method} objects representing all the
2343 * declared methods of this class
2344 *
2345 * @jls 8.2 Class Members
2346 * @jls 8.4 Method Declarations
2347 * @see <a
2348 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2349 * programming language and JVM modeling in core reflection</a>
2350 * @since 1.1
2351 */
2352 public Method[] getDeclaredMethods() {
2353 return copyMethods(privateGetDeclaredMethods(false));
2354 }
2355
2356 /**
2357 * Returns an array of {@code Constructor} objects reflecting all the
2358 * constructors implicitly or explicitly declared by the class represented by this
2359 * {@code Class} object. These are public, protected, default
2360 * (package) access, and private constructors. The elements in the array
2361 * returned are not sorted and are not in any particular order. If the
2362 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2363 * If a record class has a canonical constructor (JLS {@jls
2364 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2365 *
2366 * This method returns an array of length 0 if this {@code Class}
2367 * object represents an interface, a primitive type, an array class, or
2368 * void.
2369 *
2370 * @return the array of {@code Constructor} objects representing all the
2371 * declared constructors of this class
2372 *
2373 * @since 1.1
2374 * @see #getConstructors()
2375 * @jls 8.8 Constructor Declarations
2376 */
2377 public Constructor<?>[] getDeclaredConstructors() {
2378 return copyConstructors(privateGetDeclaredConstructors(false));
2379 }
2380
2381
2382 /**
2383 * Returns a {@code Field} object that reflects the specified declared
2384 * field of the class or interface represented by this {@code Class}
2385 * object. The {@code name} parameter is a {@code String} that specifies
2386 * the simple name of the desired field.
2387 *
2388 * <p> If this {@code Class} object represents an array type, then this
2389 * method does not find the {@code length} field of the array type.
2390 *
2391 * @param name the name of the field
2392 * @return the {@code Field} object for the specified field in this
2393 * class
2394 * @throws NoSuchFieldException if a field with the specified name is
2395 * not found.
2396 * @throws NullPointerException if {@code name} is {@code null}
2397 *
2398 * @since 1.1
2399 * @jls 8.2 Class Members
2400 * @jls 8.3 Field Declarations
2401 */
2402 public Field getDeclaredField(String name) throws NoSuchFieldException {
2403 Objects.requireNonNull(name);
2404 Field field = searchFields(privateGetDeclaredFields(false), name);
2405 if (field == null) {
2406 throw new NoSuchFieldException(name);
2407 }
2408 return getReflectionFactory().copyField(field);
2409 }
2410
2411
2412 /**
2413 * Returns a {@code Method} object that reflects the specified
2414 * declared method of the class or interface represented by this
2415 * {@code Class} object. The {@code name} parameter is a
2416 * {@code String} that specifies the simple name of the desired
2417 * method, and the {@code parameterTypes} parameter is an array of
2418 * {@code Class} objects that identify the method's formal parameter
2419 * types, in declared order. If more than one method with the same
2420 * parameter types is declared in a class, and one of these methods has a
2421 * return type that is more specific than any of the others, that method is
2422 * returned; otherwise one of the methods is chosen arbitrarily. If the
2423 * name is {@value ConstantDescs#INIT_NAME} or {@value
2424 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2425 * is raised.
2426 *
2427 * <p> If this {@code Class} object represents an array type, then this
2428 * method does not find the {@code clone()} method.
2429 *
2430 * @param name the name of the method
2431 * @param parameterTypes the parameter array
2432 * @return the {@code Method} object for the method of this class
2433 * matching the specified name and parameters
2434 * @throws NoSuchMethodException if a matching method is not found.
2435 * @throws NullPointerException if {@code name} is {@code null}
2436 *
2437 * @jls 8.2 Class Members
2438 * @jls 8.4 Method Declarations
2439 * @since 1.1
2440 */
2441 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2442 throws NoSuchMethodException {
2443 Objects.requireNonNull(name);
2444 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2445 if (method == null) {
2446 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2447 }
2448 return getReflectionFactory().copyMethod(method);
2449 }
2450
2451 /**
2452 * Returns the list of {@code Method} objects for the declared public
2453 * methods of this class or interface that have the specified method name
2454 * and parameter types.
2455 *
2456 * @param name the name of the method
2457 * @param parameterTypes the parameter array
2458 * @return the list of {@code Method} objects for the public methods of
2459 * this class matching the specified name and parameters
2460 */
2461 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2462 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2463 ReflectionFactory factory = getReflectionFactory();
2464 List<Method> result = new ArrayList<>();
2465 for (Method method : methods) {
2466 if (method.getName().equals(name)
2467 && Arrays.equals(
2468 factory.getExecutableSharedParameterTypes(method),
2469 parameterTypes)) {
2470 result.add(factory.copyMethod(method));
2471 }
2472 }
2473 return result;
2474 }
2475
2476 /**
2477 * Returns the most specific {@code Method} object of this class, super class or
2478 * interface that have the specified method name and parameter types.
2479 *
2480 * @param publicOnly true if only public methods are examined, otherwise all methods
2481 * @param name the name of the method
2482 * @param parameterTypes the parameter array
2483 * @return the {@code Method} object for the method found from this class matching
2484 * the specified name and parameters, or null if not found
2485 */
2486 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2487 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2488 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2489 }
2490
2491 /**
2492 * Returns a {@code Constructor} object that reflects the specified
2493 * constructor of the class represented by this
2494 * {@code Class} object. The {@code parameterTypes} parameter is
2495 * an array of {@code Class} objects that identify the constructor's
2496 * formal parameter types, in declared order.
2497 *
2498 * If this {@code Class} object represents an inner class
2499 * declared in a non-static context, the formal parameter types
2500 * include the explicit enclosing instance as the first parameter.
2501 *
2502 * @param parameterTypes the parameter array
2503 * @return The {@code Constructor} object for the constructor with the
2504 * specified parameter list
2505 * @throws NoSuchMethodException if a matching constructor is not found,
2506 * including when this {@code Class} object represents
2507 * an interface, a primitive type, an array class, or void.
2508 *
2509 * @see #getConstructor(Class[])
2510 * @since 1.1
2511 */
2512 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2513 throws NoSuchMethodException {
2514 return getReflectionFactory().copyConstructor(
2515 getConstructor0(parameterTypes, Member.DECLARED));
2516 }
2517
2518 /**
2519 * Finds a resource with a given name.
2520 *
2521 * <p> If this class is in a named {@link Module Module} then this method
2522 * will attempt to find the resource in the module. This is done by
2523 * delegating to the module's class loader {@link
2524 * ClassLoader#findResource(String,String) findResource(String,String)}
2525 * method, invoking it with the module name and the absolute name of the
2526 * resource. Resources in named modules are subject to the rules for
2527 * encapsulation specified in the {@code Module} {@link
2528 * Module#getResourceAsStream getResourceAsStream} method and so this
2529 * method returns {@code null} when the resource is a
2530 * non-"{@code .class}" resource in a package that is not open to the
2531 * caller's module.
2532 *
2533 * <p> Otherwise, if this class is not in a named module then the rules for
2534 * searching resources associated with a given class are implemented by the
2535 * defining {@linkplain ClassLoader class loader} of the class. This method
2536 * delegates to this {@code Class} object's class loader.
2537 * If this {@code Class} object was loaded by the bootstrap class loader,
2538 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2539 *
2540 * <p> Before delegation, an absolute resource name is constructed from the
2541 * given resource name using this algorithm:
2542 *
2543 * <ul>
2544 *
2545 * <li> If the {@code name} begins with a {@code '/'}
2546 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2547 * portion of the {@code name} following the {@code '/'}.
2548 *
2549 * <li> Otherwise, the absolute name is of the following form:
2550 *
2551 * <blockquote>
2552 * {@code modified_package_name/name}
2553 * </blockquote>
2554 *
2555 * <p> Where the {@code modified_package_name} is the package name of this
2556 * object with {@code '/'} substituted for {@code '.'}
2557 * (<code>'\u002e'</code>).
2558 *
2559 * </ul>
2560 *
2561 * @param name name of the desired resource
2562 * @return A {@link java.io.InputStream} object; {@code null} if no
2563 * resource with this name is found, or the resource is in a package
2564 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2565 * least the caller module.
2566 * @throws NullPointerException If {@code name} is {@code null}
2567 *
2568 * @see Module#getResourceAsStream(String)
2569 * @since 1.1
2570 */
2571 @CallerSensitive
2572 public InputStream getResourceAsStream(String name) {
2573 name = resolveName(name);
2574
2575 Module thisModule = getModule();
2576 if (thisModule.isNamed()) {
2577 // check if resource can be located by caller
2578 if (Resources.canEncapsulate(name)
2579 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2580 return null;
2581 }
2582
2583 // resource not encapsulated or in package open to caller
2584 String mn = thisModule.getName();
2585 ClassLoader cl = classLoader;
2586 try {
2587
2588 // special-case built-in class loaders to avoid the
2589 // need for a URL connection
2590 if (cl == null) {
2591 return BootLoader.findResourceAsStream(mn, name);
2592 } else if (cl instanceof BuiltinClassLoader bcl) {
2593 return bcl.findResourceAsStream(mn, name);
2594 } else {
2595 URL url = cl.findResource(mn, name);
2596 return (url != null) ? url.openStream() : null;
2597 }
2598
2599 } catch (IOException | SecurityException e) {
2600 return null;
2601 }
2602 }
2603
2604 // unnamed module
2605 ClassLoader cl = classLoader;
2606 if (cl == null) {
2607 return ClassLoader.getSystemResourceAsStream(name);
2608 } else {
2609 return cl.getResourceAsStream(name);
2610 }
2611 }
2612
2613 /**
2614 * Finds a resource with a given name.
2615 *
2616 * <p> If this class is in a named {@link Module Module} then this method
2617 * will attempt to find the resource in the module. This is done by
2618 * delegating to the module's class loader {@link
2619 * ClassLoader#findResource(String,String) findResource(String,String)}
2620 * method, invoking it with the module name and the absolute name of the
2621 * resource. Resources in named modules are subject to the rules for
2622 * encapsulation specified in the {@code Module} {@link
2623 * Module#getResourceAsStream getResourceAsStream} method and so this
2624 * method returns {@code null} when the resource is a
2625 * non-"{@code .class}" resource in a package that is not open to the
2626 * caller's module.
2627 *
2628 * <p> Otherwise, if this class is not in a named module then the rules for
2629 * searching resources associated with a given class are implemented by the
2630 * defining {@linkplain ClassLoader class loader} of the class. This method
2631 * delegates to this {@code Class} object's class loader.
2632 * If this {@code Class} object was loaded by the bootstrap class loader,
2633 * the method delegates to {@link ClassLoader#getSystemResource}.
2634 *
2635 * <p> Before delegation, an absolute resource name is constructed from the
2636 * given resource name using this algorithm:
2637 *
2638 * <ul>
2639 *
2640 * <li> If the {@code name} begins with a {@code '/'}
2641 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2642 * portion of the {@code name} following the {@code '/'}.
2643 *
2644 * <li> Otherwise, the absolute name is of the following form:
2645 *
2646 * <blockquote>
2647 * {@code modified_package_name/name}
2648 * </blockquote>
2649 *
2650 * <p> Where the {@code modified_package_name} is the package name of this
2651 * object with {@code '/'} substituted for {@code '.'}
2652 * (<code>'\u002e'</code>).
2653 *
2654 * </ul>
2655 *
2656 * @param name name of the desired resource
2657 * @return A {@link java.net.URL} object; {@code null} if no resource with
2658 * this name is found, the resource cannot be located by a URL, or the
2659 * resource is in a package that is not
2660 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2661 * module.
2662 * @throws NullPointerException If {@code name} is {@code null}
2663 * @since 1.1
2664 */
2665 @CallerSensitive
2666 public URL getResource(String name) {
2667 name = resolveName(name);
2668
2669 Module thisModule = getModule();
2670 if (thisModule.isNamed()) {
2671 // check if resource can be located by caller
2672 if (Resources.canEncapsulate(name)
2673 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2674 return null;
2675 }
2676
2677 // resource not encapsulated or in package open to caller
2678 String mn = thisModule.getName();
2679 ClassLoader cl = classLoader;
2680 try {
2681 if (cl == null) {
2682 return BootLoader.findResource(mn, name);
2683 } else {
2684 return cl.findResource(mn, name);
2685 }
2686 } catch (IOException ioe) {
2687 return null;
2688 }
2689 }
2690
2691 // unnamed module
2692 ClassLoader cl = classLoader;
2693 if (cl == null) {
2694 return ClassLoader.getSystemResource(name);
2695 } else {
2696 return cl.getResource(name);
2697 }
2698 }
2699
2700 /**
2701 * Returns true if a resource with the given name can be located by the
2702 * given caller. All resources in a module can be located by code in
2703 * the module. For other callers, then the package needs to be open to
2704 * the caller.
2705 */
2706 private boolean isOpenToCaller(String name, Class<?> caller) {
2707 // assert getModule().isNamed();
2708 Module thisModule = getModule();
2709 Module callerModule = (caller != null) ? caller.getModule() : null;
2710 if (callerModule != thisModule) {
2711 String pn = Resources.toPackageName(name);
2712 if (thisModule.getDescriptor().packages().contains(pn)) {
2713 if (callerModule == null) {
2714 // no caller, return true if the package is open to all modules
2715 return thisModule.isOpen(pn);
2716 }
2717 if (!thisModule.isOpen(pn, callerModule)) {
2718 // package not open to caller
2719 return false;
2720 }
2721 }
2722 }
2723 return true;
2724 }
2725
2726 private transient final ProtectionDomain protectionDomain;
2727
2728 /** Holder for the protection domain returned when the internal domain is null */
2729 private static class Holder {
2730 private static final ProtectionDomain allPermDomain;
2731 static {
2732 Permissions perms = new Permissions();
2733 perms.add(new AllPermission());
2734 allPermDomain = new ProtectionDomain(null, perms);
2735 }
2736 }
2737
2738 /**
2739 * Returns the {@code ProtectionDomain} of this class.
2740 *
2741 * @return the ProtectionDomain of this class
2742 *
2743 * @see java.security.ProtectionDomain
2744 * @since 1.2
2745 */
2746 public ProtectionDomain getProtectionDomain() {
2747 if (protectionDomain == null) {
2748 return Holder.allPermDomain;
2749 } else {
2750 return protectionDomain;
2751 }
2752 }
2753
2754 /*
2755 * Returns the Class object for the named primitive type. Type parameter T
2756 * avoids redundant casts for trusted code.
2757 */
2758 static native <T> Class<T> getPrimitiveClass(String name);
2759
2760 /**
2761 * Add a package name prefix if the name is not absolute. Remove leading "/"
2762 * if name is absolute
2763 */
2764 private String resolveName(String name) {
2765 if (!name.startsWith("/")) {
2766 String baseName = getPackageName();
2767 if (!baseName.isEmpty()) {
2768 int len = baseName.length() + 1 + name.length();
2769 StringBuilder sb = new StringBuilder(len);
2770 name = sb.append(baseName.replace('.', '/'))
2771 .append('/')
2772 .append(name)
2773 .toString();
2774 }
2775 } else {
2776 name = name.substring(1);
2777 }
2778 return name;
2779 }
2780
2781 /**
2782 * Atomic operations support.
2783 */
2784 private static class Atomic {
2785 // initialize Unsafe machinery here, since we need to call Class.class instance method
2786 // and have to avoid calling it in the static initializer of the Class class...
2787 private static final Unsafe unsafe = Unsafe.getUnsafe();
2788 // offset of Class.reflectionData instance field
2789 private static final long reflectionDataOffset
2790 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2791 // offset of Class.annotationType instance field
2792 private static final long annotationTypeOffset
2793 = unsafe.objectFieldOffset(Class.class, "annotationType");
2794 // offset of Class.annotationData instance field
2795 private static final long annotationDataOffset
2796 = unsafe.objectFieldOffset(Class.class, "annotationData");
2797
2798 static <T> boolean casReflectionData(Class<?> clazz,
2799 ReflectionData<T> oldData,
2800 ReflectionData<T> newData) {
2801 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2802 }
2803
2804 static boolean casAnnotationType(Class<?> clazz,
2805 AnnotationType oldType,
2806 AnnotationType newType) {
2807 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2808 }
2809
2810 static boolean casAnnotationData(Class<?> clazz,
2811 AnnotationData oldData,
2812 AnnotationData newData) {
2813 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2814 }
2815 }
2816
2817 /**
2818 * Reflection support.
2819 */
2820
2821 // Reflection data caches various derived names and reflective members. Cached
2822 // values may be invalidated when JVM TI RedefineClasses() is called
2823 private static class ReflectionData<T> {
2824 volatile Field[] declaredFields;
2825 volatile Field[] publicFields;
2826 volatile Method[] declaredMethods;
2827 volatile Method[] publicMethods;
2828 volatile Constructor<T>[] declaredConstructors;
2829 volatile Constructor<T>[] publicConstructors;
2830 // Intermediate results for getFields and getMethods
2831 volatile Field[] declaredPublicFields;
2832 volatile Method[] declaredPublicMethods;
2833 volatile Class<?>[] interfaces;
2834
2835 // Cached names
2836 String simpleName;
2837 String canonicalName;
2838 static final String NULL_SENTINEL = new String();
2839
2840 // Value of classRedefinedCount when we created this ReflectionData instance
2841 final int redefinedCount;
2842
2843 ReflectionData(int redefinedCount) {
2844 this.redefinedCount = redefinedCount;
2845 }
2846 }
2847
2848 private transient volatile ReflectionData<T> reflectionData;
2849
2850 // Incremented by the VM on each call to JVM TI RedefineClasses()
2851 // that redefines this class or a superclass.
2852 private transient volatile int classRedefinedCount;
2853
2854 // Lazily create and cache ReflectionData
2855 private ReflectionData<T> reflectionData() {
2856 ReflectionData<T> reflectionData = this.reflectionData;
2857 int classRedefinedCount = this.classRedefinedCount;
2858 if (reflectionData != null &&
2859 reflectionData.redefinedCount == classRedefinedCount) {
2860 return reflectionData;
2861 }
2862 // else no SoftReference or cleared SoftReference or stale ReflectionData
2863 // -> create and replace new instance
2864 return newReflectionData(reflectionData, classRedefinedCount);
2865 }
2866
2867 private ReflectionData<T> newReflectionData(ReflectionData<T> oldReflectionData,
2868 int classRedefinedCount) {
2869 while (true) {
2870 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2871 // try to CAS it...
2872 if (Atomic.casReflectionData(this, oldReflectionData, rd)) {
2873 return rd;
2874 }
2875 // else retry
2876 oldReflectionData = this.reflectionData;
2877 classRedefinedCount = this.classRedefinedCount;
2878 if (oldReflectionData != null && oldReflectionData.redefinedCount == classRedefinedCount) {
2879 return rd;
2880 }
2881 }
2882 }
2883
2884 // Generic signature handling
2885 private native String getGenericSignature0();
2886
2887 // Generic info repository; lazily initialized
2888 private transient volatile ClassRepository genericInfo;
2889
2890 // accessor for factory
2891 private GenericsFactory getFactory() {
2892 // create scope and factory
2893 return CoreReflectionFactory.make(this, ClassScope.make(this));
2894 }
2895
2896 // accessor for generic info repository;
2897 // generic info is lazily initialized
2898 private ClassRepository getGenericInfo() {
2899 ClassRepository genericInfo = this.genericInfo;
2900 if (genericInfo == null) {
2901 String signature = getGenericSignature0();
2902 if (signature == null) {
2903 genericInfo = ClassRepository.NONE;
2904 } else {
2905 genericInfo = ClassRepository.make(signature, getFactory());
2906 }
2907 this.genericInfo = genericInfo;
2908 }
2909 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2910 }
2911
2912 // Annotations handling
2913 native byte[] getRawAnnotations();
2914 // Since 1.8
2915 native byte[] getRawTypeAnnotations();
2916 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2917 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2918 }
2919
2920 native ConstantPool getConstantPool();
2921
2922 //
2923 //
2924 // java.lang.reflect.Field handling
2925 //
2926 //
2927
2928 // Returns an array of "root" fields. These Field objects must NOT
2929 // be propagated to the outside world, but must instead be copied
2930 // via ReflectionFactory.copyField.
2931 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2932 Field[] res;
2933 ReflectionData<T> rd = reflectionData();
2934 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2935 if (res != null) return res;
2936 // No cached value available; request value from VM
2937 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2938 if (publicOnly) {
2939 rd.declaredPublicFields = res;
2940 } else {
2941 rd.declaredFields = res;
2942 }
2943 return res;
2944 }
2945
2946 // Returns an array of "root" fields. These Field objects must NOT
2947 // be propagated to the outside world, but must instead be copied
2948 // via ReflectionFactory.copyField.
2949 private Field[] privateGetPublicFields() {
2950 Field[] res;
2951 ReflectionData<T> rd = reflectionData();
2952 res = rd.publicFields;
2953 if (res != null) return res;
2954
2955 // Use a linked hash set to ensure order is preserved and
2956 // fields from common super interfaces are not duplicated
2957 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2958
2959 // Local fields
2960 addAll(fields, privateGetDeclaredFields(true));
2961
2962 // Direct superinterfaces, recursively
2963 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2964 addAll(fields, si.privateGetPublicFields());
2965 }
2966
2967 // Direct superclass, recursively
2968 Class<?> sc = getSuperclass();
2969 if (sc != null) {
2970 addAll(fields, sc.privateGetPublicFields());
2971 }
2972
2973 res = fields.toArray(new Field[0]);
2974 rd.publicFields = res;
2975 return res;
2976 }
2977
2978 private static void addAll(Collection<Field> c, Field[] o) {
2979 for (Field f : o) {
2980 c.add(f);
2981 }
2982 }
2983
2984
2985 //
2986 //
2987 // java.lang.reflect.Constructor handling
2988 //
2989 //
2990
2991 // Returns an array of "root" constructors. These Constructor
2992 // objects must NOT be propagated to the outside world, but must
2993 // instead be copied via ReflectionFactory.copyConstructor.
2994 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
2995 Constructor<T>[] res;
2996 ReflectionData<T> rd = reflectionData();
2997 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
2998 if (res != null) return res;
2999 // No cached value available; request value from VM
3000 if (isInterface()) {
3001 @SuppressWarnings("unchecked")
3002 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3003 res = temporaryRes;
3004 } else {
3005 res = getDeclaredConstructors0(publicOnly);
3006 }
3007 if (publicOnly) {
3008 rd.publicConstructors = res;
3009 } else {
3010 rd.declaredConstructors = res;
3011 }
3012 return res;
3013 }
3014
3015 //
3016 //
3017 // java.lang.reflect.Method handling
3018 //
3019 //
3020
3021 // Returns an array of "root" methods. These Method objects must NOT
3022 // be propagated to the outside world, but must instead be copied
3023 // via ReflectionFactory.copyMethod.
3024 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3025 Method[] res;
3026 ReflectionData<T> rd = reflectionData();
3027 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3028 if (res != null) return res;
3029 // No cached value available; request value from VM
3030 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3031 if (publicOnly) {
3032 rd.declaredPublicMethods = res;
3033 } else {
3034 rd.declaredMethods = res;
3035 }
3036 return res;
3037 }
3038
3039 // Returns an array of "root" methods. These Method objects must NOT
3040 // be propagated to the outside world, but must instead be copied
3041 // via ReflectionFactory.copyMethod.
3042 private Method[] privateGetPublicMethods() {
3043 Method[] res;
3044 ReflectionData<T> rd = reflectionData();
3045 res = rd.publicMethods;
3046 if (res != null) return res;
3047
3048 // No cached value available; compute value recursively.
3049 // Start by fetching public declared methods...
3050 PublicMethods pms = new PublicMethods();
3051 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3052 pms.merge(m);
3053 }
3054 // ...then recur over superclass methods...
3055 Class<?> sc = getSuperclass();
3056 if (sc != null) {
3057 for (Method m : sc.privateGetPublicMethods()) {
3058 pms.merge(m);
3059 }
3060 }
3061 // ...and finally over direct superinterfaces.
3062 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3063 for (Method m : intf.privateGetPublicMethods()) {
3064 // static interface methods are not inherited
3065 if (!Modifier.isStatic(m.getModifiers())) {
3066 pms.merge(m);
3067 }
3068 }
3069 }
3070
3071 res = pms.toArray();
3072 rd.publicMethods = res;
3073 return res;
3074 }
3075
3076
3077 //
3078 // Helpers for fetchers of one field, method, or constructor
3079 //
3080
3081 // This method does not copy the returned Field object!
3082 private static Field searchFields(Field[] fields, String name) {
3083 for (Field field : fields) {
3084 if (field.getName().equals(name)) {
3085 return field;
3086 }
3087 }
3088 return null;
3089 }
3090
3091 // Returns a "root" Field object. This Field object must NOT
3092 // be propagated to the outside world, but must instead be copied
3093 // via ReflectionFactory.copyField.
3094 private Field getField0(String name) {
3095 // Note: the intent is that the search algorithm this routine
3096 // uses be equivalent to the ordering imposed by
3097 // privateGetPublicFields(). It fetches only the declared
3098 // public fields for each class, however, to reduce the number
3099 // of Field objects which have to be created for the common
3100 // case where the field being requested is declared in the
3101 // class which is being queried.
3102 Field res;
3103 // Search declared public fields
3104 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3105 return res;
3106 }
3107 // Direct superinterfaces, recursively
3108 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3109 for (Class<?> c : interfaces) {
3110 if ((res = c.getField0(name)) != null) {
3111 return res;
3112 }
3113 }
3114 // Direct superclass, recursively
3115 if (!isInterface()) {
3116 Class<?> c = getSuperclass();
3117 if (c != null) {
3118 if ((res = c.getField0(name)) != null) {
3119 return res;
3120 }
3121 }
3122 }
3123 return null;
3124 }
3125
3126 // This method does not copy the returned Method object!
3127 private static Method searchMethods(Method[] methods,
3128 String name,
3129 Class<?>[] parameterTypes)
3130 {
3131 ReflectionFactory fact = getReflectionFactory();
3132 Method res = null;
3133 for (Method m : methods) {
3134 if (m.getName().equals(name)
3135 && arrayContentsEq(parameterTypes,
3136 fact.getExecutableSharedParameterTypes(m))
3137 && (res == null
3138 || (res.getReturnType() != m.getReturnType()
3139 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3140 res = m;
3141 }
3142 return res;
3143 }
3144
3145 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3146
3147 // Returns a "root" Method object. This Method object must NOT
3148 // be propagated to the outside world, but must instead be copied
3149 // via ReflectionFactory.copyMethod.
3150 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3151 PublicMethods.MethodList res = getMethodsRecursive(
3152 name,
3153 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3154 /* includeStatic */ true, /* publicOnly */ true);
3155 return res == null ? null : res.getMostSpecific();
3156 }
3157
3158 // Returns a list of "root" Method objects. These Method objects must NOT
3159 // be propagated to the outside world, but must instead be copied
3160 // via ReflectionFactory.copyMethod.
3161 private PublicMethods.MethodList getMethodsRecursive(String name,
3162 Class<?>[] parameterTypes,
3163 boolean includeStatic,
3164 boolean publicOnly) {
3165 // 1st check declared methods
3166 Method[] methods = privateGetDeclaredMethods(publicOnly);
3167 PublicMethods.MethodList res = PublicMethods.MethodList
3168 .filter(methods, name, parameterTypes, includeStatic);
3169 // if there is at least one match among declared methods, we need not
3170 // search any further as such match surely overrides matching methods
3171 // declared in superclass(es) or interface(s).
3172 if (res != null) {
3173 return res;
3174 }
3175
3176 // if there was no match among declared methods,
3177 // we must consult the superclass (if any) recursively...
3178 Class<?> sc = getSuperclass();
3179 if (sc != null) {
3180 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3181 }
3182
3183 // ...and coalesce the superclass methods with methods obtained
3184 // from directly implemented interfaces excluding static methods...
3185 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3186 res = PublicMethods.MethodList.merge(
3187 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3188 }
3189
3190 return res;
3191 }
3192
3193 // Returns a "root" Constructor object. This Constructor object must NOT
3194 // be propagated to the outside world, but must instead be copied
3195 // via ReflectionFactory.copyConstructor.
3196 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3197 int which) throws NoSuchMethodException
3198 {
3199 ReflectionFactory fact = getReflectionFactory();
3200 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3201 for (Constructor<T> constructor : constructors) {
3202 if (arrayContentsEq(parameterTypes,
3203 fact.getExecutableSharedParameterTypes(constructor))) {
3204 return constructor;
3205 }
3206 }
3207 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3208 }
3209
3210 //
3211 // Other helpers and base implementation
3212 //
3213
3214 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3215 if (a1 == null) {
3216 return a2 == null || a2.length == 0;
3217 }
3218
3219 if (a2 == null) {
3220 return a1.length == 0;
3221 }
3222
3223 if (a1.length != a2.length) {
3224 return false;
3225 }
3226
3227 for (int i = 0; i < a1.length; i++) {
3228 if (a1[i] != a2[i]) {
3229 return false;
3230 }
3231 }
3232
3233 return true;
3234 }
3235
3236 private static Field[] copyFields(Field[] arg) {
3237 Field[] out = new Field[arg.length];
3238 ReflectionFactory fact = getReflectionFactory();
3239 for (int i = 0; i < arg.length; i++) {
3240 out[i] = fact.copyField(arg[i]);
3241 }
3242 return out;
3243 }
3244
3245 private static Method[] copyMethods(Method[] arg) {
3246 Method[] out = new Method[arg.length];
3247 ReflectionFactory fact = getReflectionFactory();
3248 for (int i = 0; i < arg.length; i++) {
3249 out[i] = fact.copyMethod(arg[i]);
3250 }
3251 return out;
3252 }
3253
3254 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3255 Constructor<U>[] out = arg.clone();
3256 ReflectionFactory fact = getReflectionFactory();
3257 for (int i = 0; i < out.length; i++) {
3258 out[i] = fact.copyConstructor(out[i]);
3259 }
3260 return out;
3261 }
3262
3263 private native Field[] getDeclaredFields0(boolean publicOnly);
3264 private native Method[] getDeclaredMethods0(boolean publicOnly);
3265 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3266 private native Class<?>[] getDeclaredClasses0();
3267
3268 /*
3269 * Returns an array containing the components of the Record attribute,
3270 * or null if the attribute is not present.
3271 *
3272 * Note that this method returns non-null array on a class with
3273 * the Record attribute even if this class is not a record.
3274 */
3275 private native RecordComponent[] getRecordComponents0();
3276 private native boolean isRecord0();
3277
3278 /**
3279 * Helper method to get the method name from arguments.
3280 */
3281 private String methodToString(String name, Class<?>[] argTypes) {
3282 return getName() + '.' + name +
3283 ((argTypes == null || argTypes.length == 0) ?
3284 "()" :
3285 Arrays.stream(argTypes)
3286 .map(c -> c == null ? "null" : c.getName())
3287 .collect(Collectors.joining(",", "(", ")")));
3288 }
3289
3290 /** use serialVersionUID from JDK 1.1 for interoperability */
3291 @java.io.Serial
3292 private static final long serialVersionUID = 3206093459760846163L;
3293
3294
3295 /**
3296 * Class Class is special cased within the Serialization Stream Protocol.
3297 *
3298 * A Class instance is written initially into an ObjectOutputStream in the
3299 * following format:
3300 * <pre>
3301 * {@code TC_CLASS} ClassDescriptor
3302 * A ClassDescriptor is a special cased serialization of
3303 * a {@code java.io.ObjectStreamClass} instance.
3304 * </pre>
3305 * A new handle is generated for the initial time the class descriptor
3306 * is written into the stream. Future references to the class descriptor
3307 * are written as references to the initial class descriptor instance.
3308 *
3309 * @see java.io.ObjectStreamClass
3310 */
3311 @java.io.Serial
3312 private static final ObjectStreamField[] serialPersistentFields =
3313 new ObjectStreamField[0];
3314
3315
3316 /**
3317 * Returns the assertion status that would be assigned to this
3318 * class if it were to be initialized at the time this method is invoked.
3319 * If this class has had its assertion status set, the most recent
3320 * setting will be returned; otherwise, if any package default assertion
3321 * status pertains to this class, the most recent setting for the most
3322 * specific pertinent package default assertion status is returned;
3323 * otherwise, if this class is not a system class (i.e., it has a
3324 * class loader) its class loader's default assertion status is returned;
3325 * otherwise, the system class default assertion status is returned.
3326 *
3327 * @apiNote
3328 * Few programmers will have any need for this method; it is provided
3329 * for the benefit of the JDK itself. (It allows a class to determine at
3330 * the time that it is initialized whether assertions should be enabled.)
3331 * Note that this method is not guaranteed to return the actual
3332 * assertion status that was (or will be) associated with the specified
3333 * class when it was (or will be) initialized.
3334 *
3335 * @return the desired assertion status of the specified class.
3336 * @see java.lang.ClassLoader#setClassAssertionStatus
3337 * @see java.lang.ClassLoader#setPackageAssertionStatus
3338 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3339 * @since 1.4
3340 */
3341 public boolean desiredAssertionStatus() {
3342 ClassLoader loader = classLoader;
3343 // If the loader is null this is a system class, so ask the VM
3344 if (loader == null)
3345 return desiredAssertionStatus0(this);
3346
3347 // If the classloader has been initialized with the assertion
3348 // directives, ask it. Otherwise, ask the VM.
3349 synchronized(loader.assertionLock) {
3350 if (loader.classAssertionStatus != null) {
3351 return loader.desiredAssertionStatus(getName());
3352 }
3353 }
3354 return desiredAssertionStatus0(this);
3355 }
3356
3357 // Retrieves the desired assertion status of this class from the VM
3358 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3359
3360 /**
3361 * Returns true if and only if this class was declared as an enum in the
3362 * source code.
3363 *
3364 * Note that {@link java.lang.Enum} is not itself an enum class.
3365 *
3366 * Also note that if an enum constant is declared with a class body,
3367 * the class of that enum constant object is an anonymous class
3368 * and <em>not</em> the class of the declaring enum class. The
3369 * {@link Enum#getDeclaringClass} method of an enum constant can
3370 * be used to get the class of the enum class declaring the
3371 * constant.
3372 *
3373 * @return true if and only if this class was declared as an enum in the
3374 * source code
3375 * @since 1.5
3376 * @jls 8.9.1 Enum Constants
3377 */
3378 public boolean isEnum() {
3379 // An enum must both directly extend java.lang.Enum and have
3380 // the ENUM bit set; classes for specialized enum constants
3381 // don't do the former.
3382 return (this.getModifiers() & ENUM) != 0 &&
3383 this.getSuperclass() == java.lang.Enum.class;
3384 }
3385
3386 /**
3387 * Returns {@code true} if and only if this class is a record class.
3388 *
3389 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3390 * class is {@code java.lang.Record}. A record class is {@linkplain
3391 * Modifier#FINAL final}. A record class has (possibly zero) record
3392 * components; {@link #getRecordComponents()} returns a non-null but
3393 * possibly empty value for a record.
3394 *
3395 * <p> Note that class {@link Record} is not a record class and thus
3396 * invoking this method on class {@code Record} returns {@code false}.
3397 *
3398 * @return true if and only if this class is a record class, otherwise false
3399 * @jls 8.10 Record Classes
3400 * @since 16
3401 */
3402 public boolean isRecord() {
3403 // this superclass and final modifier check is not strictly necessary
3404 // they are intrinsified and serve as a fast-path check
3405 return getSuperclass() == java.lang.Record.class &&
3406 (this.getModifiers() & Modifier.FINAL) != 0 &&
3407 isRecord0();
3408 }
3409
3410 // Fetches the factory for reflective objects
3411 private static ReflectionFactory getReflectionFactory() {
3412 var factory = reflectionFactory;
3413 if (factory != null) {
3414 return factory;
3415 }
3416 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3417 }
3418 private static ReflectionFactory reflectionFactory;
3419
3420 /**
3421 * When CDS is enabled, the Class class may be aot-initialized. However,
3422 * we can't archive reflectionFactory, so we reset it to null, so it
3423 * will be allocated again at runtime.
3424 */
3425 private static void resetArchivedStates() {
3426 reflectionFactory = null;
3427 }
3428
3429 /**
3430 * Returns the elements of this enum class or null if this
3431 * Class object does not represent an enum class.
3432 *
3433 * @return an array containing the values comprising the enum class
3434 * represented by this {@code Class} object in the order they're
3435 * declared, or null if this {@code Class} object does not
3436 * represent an enum class
3437 * @since 1.5
3438 * @jls 8.9.1 Enum Constants
3439 */
3440 public T[] getEnumConstants() {
3441 T[] values = getEnumConstantsShared();
3442 return (values != null) ? values.clone() : null;
3443 }
3444
3445 /**
3446 * Returns the elements of this enum class or null if this
3447 * Class object does not represent an enum class;
3448 * identical to getEnumConstants except that the result is
3449 * uncloned, cached, and shared by all callers.
3450 */
3451 T[] getEnumConstantsShared() {
3452 T[] constants = enumConstants;
3453 if (constants == null) {
3454 if (!isEnum()) return null;
3455 try {
3456 final Method values = getMethod("values");
3457 values.setAccessible(true);
3458 @SuppressWarnings("unchecked")
3459 T[] temporaryConstants = (T[])values.invoke(null);
3460 enumConstants = constants = temporaryConstants;
3461 }
3462 // These can happen when users concoct enum-like classes
3463 // that don't comply with the enum spec.
3464 catch (InvocationTargetException | NoSuchMethodException |
3465 IllegalAccessException | NullPointerException |
3466 ClassCastException ex) { return null; }
3467 }
3468 return constants;
3469 }
3470 private transient volatile T[] enumConstants;
3471
3472 /**
3473 * Returns a map from simple name to enum constant. This package-private
3474 * method is used internally by Enum to implement
3475 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3476 * efficiently. Note that the map is returned by this method is
3477 * created lazily on first use. Typically it won't ever get created.
3478 */
3479 Map<String, T> enumConstantDirectory() {
3480 Map<String, T> directory = enumConstantDirectory;
3481 if (directory == null) {
3482 T[] universe = getEnumConstantsShared();
3483 if (universe == null)
3484 throw new IllegalArgumentException(
3485 getName() + " is not an enum class");
3486 directory = HashMap.newHashMap(universe.length);
3487 for (T constant : universe) {
3488 directory.put(((Enum<?>)constant).name(), constant);
3489 }
3490 enumConstantDirectory = directory;
3491 }
3492 return directory;
3493 }
3494 private transient volatile Map<String, T> enumConstantDirectory;
3495
3496 /**
3497 * Casts an object to the class or interface represented
3498 * by this {@code Class} object.
3499 *
3500 * @param obj the object to be cast
3501 * @return the object after casting, or null if obj is null
3502 *
3503 * @throws ClassCastException if the object is not
3504 * null and is not assignable to the type T.
3505 *
3506 * @since 1.5
3507 */
3508 @SuppressWarnings("unchecked")
3509 @IntrinsicCandidate
3510 public T cast(Object obj) {
3511 if (obj != null && !isInstance(obj))
3512 throw new ClassCastException(cannotCastMsg(obj));
3513 return (T) obj;
3514 }
3515
3516 private String cannotCastMsg(Object obj) {
3517 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3518 }
3519
3520 /**
3521 * Casts this {@code Class} object to represent a subclass of the class
3522 * represented by the specified class object. Checks that the cast
3523 * is valid, and throws a {@code ClassCastException} if it is not. If
3524 * this method succeeds, it always returns a reference to this {@code Class} object.
3525 *
3526 * <p>This method is useful when a client needs to "narrow" the type of
3527 * a {@code Class} object to pass it to an API that restricts the
3528 * {@code Class} objects that it is willing to accept. A cast would
3529 * generate a compile-time warning, as the correctness of the cast
3530 * could not be checked at runtime (because generic types are implemented
3531 * by erasure).
3532 *
3533 * @param <U> the type to cast this {@code Class} object to
3534 * @param clazz the class of the type to cast this {@code Class} object to
3535 * @return this {@code Class} object, cast to represent a subclass of
3536 * the specified class object.
3537 * @throws ClassCastException if this {@code Class} object does not
3538 * represent a subclass of the specified class (here "subclass" includes
3539 * the class itself).
3540 * @since 1.5
3541 */
3542 @SuppressWarnings("unchecked")
3543 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3544 if (clazz.isAssignableFrom(this))
3545 return (Class<? extends U>) this;
3546 else
3547 throw new ClassCastException(this.toString());
3548 }
3549
3550 /**
3551 * {@inheritDoc}
3552 * <p>Note that any annotation returned by this method is a
3553 * declaration annotation.
3554 *
3555 * @throws NullPointerException {@inheritDoc}
3556 * @since 1.5
3557 */
3558 @Override
3559 @SuppressWarnings("unchecked")
3560 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3561 Objects.requireNonNull(annotationClass);
3562
3563 return (A) annotationData().annotations.get(annotationClass);
3564 }
3565
3566 /**
3567 * {@inheritDoc}
3568 * @throws NullPointerException {@inheritDoc}
3569 * @since 1.5
3570 */
3571 @Override
3572 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3573 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3574 }
3575
3576 /**
3577 * {@inheritDoc}
3578 * <p>Note that any annotations returned by this method are
3579 * declaration annotations.
3580 *
3581 * @throws NullPointerException {@inheritDoc}
3582 * @since 1.8
3583 */
3584 @Override
3585 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3586 Objects.requireNonNull(annotationClass);
3587
3588 AnnotationData annotationData = annotationData();
3589 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3590 this,
3591 annotationClass);
3592 }
3593
3594 /**
3595 * {@inheritDoc}
3596 * <p>Note that any annotations returned by this method are
3597 * declaration annotations.
3598 *
3599 * @since 1.5
3600 */
3601 @Override
3602 public Annotation[] getAnnotations() {
3603 return AnnotationParser.toArray(annotationData().annotations);
3604 }
3605
3606 /**
3607 * {@inheritDoc}
3608 * <p>Note that any annotation returned by this method is a
3609 * declaration annotation.
3610 *
3611 * @throws NullPointerException {@inheritDoc}
3612 * @since 1.8
3613 */
3614 @Override
3615 @SuppressWarnings("unchecked")
3616 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3617 Objects.requireNonNull(annotationClass);
3618
3619 return (A) annotationData().declaredAnnotations.get(annotationClass);
3620 }
3621
3622 /**
3623 * {@inheritDoc}
3624 * <p>Note that any annotations returned by this method are
3625 * declaration annotations.
3626 *
3627 * @throws NullPointerException {@inheritDoc}
3628 * @since 1.8
3629 */
3630 @Override
3631 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3632 Objects.requireNonNull(annotationClass);
3633
3634 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3635 annotationClass);
3636 }
3637
3638 /**
3639 * {@inheritDoc}
3640 * <p>Note that any annotations returned by this method are
3641 * declaration annotations.
3642 *
3643 * @since 1.5
3644 */
3645 @Override
3646 public Annotation[] getDeclaredAnnotations() {
3647 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3648 }
3649
3650 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3651 private static class AnnotationData {
3652 final Map<Class<? extends Annotation>, Annotation> annotations;
3653 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3654
3655 // Value of classRedefinedCount when we created this AnnotationData instance
3656 final int redefinedCount;
3657
3658 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3659 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3660 int redefinedCount) {
3661 this.annotations = annotations;
3662 this.declaredAnnotations = declaredAnnotations;
3663 this.redefinedCount = redefinedCount;
3664 }
3665 }
3666
3667 // Annotations cache
3668 @SuppressWarnings("UnusedDeclaration")
3669 private transient volatile AnnotationData annotationData;
3670
3671 private AnnotationData annotationData() {
3672 while (true) { // retry loop
3673 AnnotationData annotationData = this.annotationData;
3674 int classRedefinedCount = this.classRedefinedCount;
3675 if (annotationData != null &&
3676 annotationData.redefinedCount == classRedefinedCount) {
3677 return annotationData;
3678 }
3679 // null or stale annotationData -> optimistically create new instance
3680 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3681 // try to install it
3682 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3683 // successfully installed new AnnotationData
3684 return newAnnotationData;
3685 }
3686 }
3687 }
3688
3689 private AnnotationData createAnnotationData(int classRedefinedCount) {
3690 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3691 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3692 Class<?> superClass = getSuperclass();
3693 Map<Class<? extends Annotation>, Annotation> annotations = null;
3694 if (superClass != null) {
3695 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3696 superClass.annotationData().annotations;
3697 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3698 Class<? extends Annotation> annotationClass = e.getKey();
3699 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3700 if (annotations == null) { // lazy construction
3701 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3702 declaredAnnotations.size(),
3703 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3704 )
3705 );
3706 }
3707 annotations.put(annotationClass, e.getValue());
3708 }
3709 }
3710 }
3711 if (annotations == null) {
3712 // no inherited annotations -> share the Map with declaredAnnotations
3713 annotations = declaredAnnotations;
3714 } else {
3715 // at least one inherited annotation -> declared may override inherited
3716 annotations.putAll(declaredAnnotations);
3717 }
3718 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3719 }
3720
3721 // Annotation interfaces cache their internal (AnnotationType) form
3722
3723 @SuppressWarnings("UnusedDeclaration")
3724 private transient volatile AnnotationType annotationType;
3725
3726 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3727 return Atomic.casAnnotationType(this, oldType, newType);
3728 }
3729
3730 AnnotationType getAnnotationType() {
3731 return annotationType;
3732 }
3733
3734 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3735 return annotationData().declaredAnnotations;
3736 }
3737
3738 /* Backing store of user-defined values pertaining to this class.
3739 * Maintained by the ClassValue class.
3740 */
3741 transient ClassValue.ClassValueMap classValueMap;
3742
3743 /**
3744 * Returns an {@code AnnotatedType} object that represents the use of a
3745 * type to specify the superclass of the entity represented by this {@code
3746 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3747 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3748 * Foo.)
3749 *
3750 * <p> If this {@code Class} object represents a class whose declaration
3751 * does not explicitly indicate an annotated superclass, then the return
3752 * value is an {@code AnnotatedType} object representing an element with no
3753 * annotations.
3754 *
3755 * <p> If this {@code Class} represents either the {@code Object} class, an
3756 * interface type, an array type, a primitive type, or void, the return
3757 * value is {@code null}.
3758 *
3759 * @return an object representing the superclass
3760 * @since 1.8
3761 */
3762 public AnnotatedType getAnnotatedSuperclass() {
3763 if (this == Object.class ||
3764 isInterface() ||
3765 isArray() ||
3766 isPrimitive() ||
3767 this == Void.TYPE) {
3768 return null;
3769 }
3770
3771 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3772 }
3773
3774 /**
3775 * Returns an array of {@code AnnotatedType} objects that represent the use
3776 * of types to specify superinterfaces of the entity represented by this
3777 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3778 * superinterface in '... implements Foo' is distinct from the
3779 * <em>declaration</em> of interface Foo.)
3780 *
3781 * <p> If this {@code Class} object represents a class, the return value is
3782 * an array containing objects representing the uses of interface types to
3783 * specify interfaces implemented by the class. The order of the objects in
3784 * the array corresponds to the order of the interface types used in the
3785 * 'implements' clause of the declaration of this {@code Class} object.
3786 *
3787 * <p> If this {@code Class} object represents an interface, the return
3788 * value is an array containing objects representing the uses of interface
3789 * types to specify interfaces directly extended by the interface. The
3790 * order of the objects in the array corresponds to the order of the
3791 * interface types used in the 'extends' clause of the declaration of this
3792 * {@code Class} object.
3793 *
3794 * <p> If this {@code Class} object represents a class or interface whose
3795 * declaration does not explicitly indicate any annotated superinterfaces,
3796 * the return value is an array of length 0.
3797 *
3798 * <p> If this {@code Class} object represents either the {@code Object}
3799 * class, an array type, a primitive type, or void, the return value is an
3800 * array of length 0.
3801 *
3802 * @return an array representing the superinterfaces
3803 * @since 1.8
3804 */
3805 public AnnotatedType[] getAnnotatedInterfaces() {
3806 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3807 }
3808
3809 private native Class<?> getNestHost0();
3810
3811 /**
3812 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3813 * or interface represented by this {@code Class} object belongs.
3814 * Every class and interface belongs to exactly one nest.
3815 *
3816 * If the nest host of this class or interface has previously
3817 * been determined, then this method returns the nest host.
3818 * If the nest host of this class or interface has
3819 * not previously been determined, then this method determines the nest
3820 * host using the algorithm of JVMS 5.4.4, and returns it.
3821 *
3822 * Often, a class or interface belongs to a nest consisting only of itself,
3823 * in which case this method returns {@code this} to indicate that the class
3824 * or interface is the nest host.
3825 *
3826 * <p>If this {@code Class} object represents a primitive type, an array type,
3827 * or {@code void}, then this method returns {@code this},
3828 * indicating that the represented entity belongs to the nest consisting only of
3829 * itself, and is the nest host.
3830 *
3831 * @return the nest host of this class or interface
3832 *
3833 * @since 11
3834 * @jvms 4.7.28 The {@code NestHost} Attribute
3835 * @jvms 4.7.29 The {@code NestMembers} Attribute
3836 * @jvms 5.4.4 Access Control
3837 */
3838 public Class<?> getNestHost() {
3839 if (isPrimitive() || isArray()) {
3840 return this;
3841 }
3842 return getNestHost0();
3843 }
3844
3845 /**
3846 * Determines if the given {@code Class} is a nestmate of the
3847 * class or interface represented by this {@code Class} object.
3848 * Two classes or interfaces are nestmates
3849 * if they have the same {@linkplain #getNestHost() nest host}.
3850 *
3851 * @param c the class to check
3852 * @return {@code true} if this class and {@code c} are members of
3853 * the same nest; and {@code false} otherwise.
3854 *
3855 * @since 11
3856 */
3857 public boolean isNestmateOf(Class<?> c) {
3858 if (this == c) {
3859 return true;
3860 }
3861 if (isPrimitive() || isArray() ||
3862 c.isPrimitive() || c.isArray()) {
3863 return false;
3864 }
3865
3866 return getNestHost() == c.getNestHost();
3867 }
3868
3869 private native Class<?>[] getNestMembers0();
3870
3871 /**
3872 * Returns an array containing {@code Class} objects representing all the
3873 * classes and interfaces that are members of the nest to which the class
3874 * or interface represented by this {@code Class} object belongs.
3875 *
3876 * First, this method obtains the {@linkplain #getNestHost() nest host},
3877 * {@code H}, of the nest to which the class or interface represented by
3878 * this {@code Class} object belongs. The zeroth element of the returned
3879 * array is {@code H}.
3880 *
3881 * Then, for each class or interface {@code C} which is recorded by {@code H}
3882 * as being a member of its nest, this method attempts to obtain the {@code Class}
3883 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3884 * loader} of the current {@code Class} object), and then obtains the
3885 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3886 * The classes and interfaces which are recorded by {@code H} as being members
3887 * of its nest, and for which {@code H} can be determined as their nest host,
3888 * are indicated by subsequent elements of the returned array. The order of
3889 * such elements is unspecified. Duplicates are permitted.
3890 *
3891 * <p>If this {@code Class} object represents a primitive type, an array type,
3892 * or {@code void}, then this method returns a single-element array containing
3893 * {@code this}.
3894 *
3895 * @apiNote
3896 * The returned array includes only the nest members recorded in the {@code NestMembers}
3897 * attribute, and not any hidden classes that were added to the nest via
3898 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3899 * Lookup::defineHiddenClass}.
3900 *
3901 * @return an array of all classes and interfaces in the same nest as
3902 * this class or interface
3903 *
3904 * @since 11
3905 * @see #getNestHost()
3906 * @jvms 4.7.28 The {@code NestHost} Attribute
3907 * @jvms 4.7.29 The {@code NestMembers} Attribute
3908 */
3909 public Class<?>[] getNestMembers() {
3910 if (isPrimitive() || isArray()) {
3911 return new Class<?>[] { this };
3912 }
3913 Class<?>[] members = getNestMembers0();
3914 // Can't actually enable this due to bootstrapping issues
3915 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3916 return members;
3917 }
3918
3919 /**
3920 * Returns the descriptor string of the entity (class, interface, array class,
3921 * primitive type, or {@code void}) represented by this {@code Class} object.
3922 *
3923 * <p> If this {@code Class} object represents a class or interface,
3924 * not an array class, then:
3925 * <ul>
3926 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3927 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3928 * for the class or interface. Calling
3929 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3930 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3931 * describing this class or interface.
3932 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3933 * then the result is a string of the form:
3934 * <blockquote>
3935 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3936 * </blockquote>
3937 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3938 * encoded in internal form indicated by the {@code class} file passed to
3939 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3940 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3941 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3942 * The result string is not a type descriptor.
3943 * </ul>
3944 *
3945 * <p> If this {@code Class} object represents an array class, then
3946 * the result is a string consisting of one or more '{@code [}' characters
3947 * representing the depth of the array nesting, followed by the
3948 * descriptor string of the element type.
3949 * <ul>
3950 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3951 * or interface, then this array class can be described nominally.
3952 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3953 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3954 * describing this array class.
3955 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3956 * interface, then this array class cannot be described nominally.
3957 * The result string is not a type descriptor.
3958 * </ul>
3959 *
3960 * <p> If this {@code Class} object represents a primitive type or
3961 * {@code void}, then the result is a field descriptor string which
3962 * is a one-letter code corresponding to a primitive type or {@code void}
3963 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3964 *
3965 * @return the descriptor string for this {@code Class} object
3966 * @jvms 4.3.2 Field Descriptors
3967 * @since 12
3968 */
3969 @Override
3970 public String descriptorString() {
3971 if (isPrimitive())
3972 return Wrapper.forPrimitiveType(this).basicTypeString();
3973
3974 if (isArray()) {
3975 return "[".concat(componentType.descriptorString());
3976 } else if (isHidden()) {
3977 String name = getName();
3978 int index = name.indexOf('/');
3979 return new StringBuilder(name.length() + 2)
3980 .append('L')
3981 .append(name.substring(0, index).replace('.', '/'))
3982 .append('.')
3983 .append(name, index + 1, name.length())
3984 .append(';')
3985 .toString();
3986 } else {
3987 String name = getName().replace('.', '/');
3988 return StringConcatHelper.concat("L", name, ";");
3989 }
3990 }
3991
3992 /**
3993 * Returns the component type of this {@code Class}, if it describes
3994 * an array type, or {@code null} otherwise.
3995 *
3996 * @implSpec
3997 * Equivalent to {@link Class#getComponentType()}.
3998 *
3999 * @return a {@code Class} describing the component type, or {@code null}
4000 * if this {@code Class} does not describe an array type
4001 * @since 12
4002 */
4003 @Override
4004 public Class<?> componentType() {
4005 return isArray() ? componentType : null;
4006 }
4007
4008 /**
4009 * Returns a {@code Class} for an array type whose component type
4010 * is described by this {@linkplain Class}.
4011 *
4012 * @throws UnsupportedOperationException if this component type is {@linkplain
4013 * Void#TYPE void} or if the number of dimensions of the resulting array
4014 * type would exceed 255.
4015 * @return a {@code Class} describing the array type
4016 * @jvms 4.3.2 Field Descriptors
4017 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4018 * @since 12
4019 */
4020 @Override
4021 public Class<?> arrayType() {
4022 try {
4023 return Array.newInstance(this, 0).getClass();
4024 } catch (IllegalArgumentException iae) {
4025 throw new UnsupportedOperationException(iae);
4026 }
4027 }
4028
4029 /**
4030 * Returns a nominal descriptor for this instance, if one can be
4031 * constructed, or an empty {@link Optional} if one cannot be.
4032 *
4033 * @return An {@link Optional} containing the resulting nominal descriptor,
4034 * or an empty {@link Optional} if one cannot be constructed.
4035 * @since 12
4036 */
4037 @Override
4038 public Optional<ClassDesc> describeConstable() {
4039 Class<?> c = isArray() ? elementType() : this;
4040 return c.isHidden() ? Optional.empty()
4041 : Optional.of(ConstantUtils.classDesc(this));
4042 }
4043
4044 /**
4045 * Returns {@code true} if and only if the underlying class is a hidden class.
4046 *
4047 * @return {@code true} if and only if this class is a hidden class.
4048 *
4049 * @since 15
4050 * @see MethodHandles.Lookup#defineHiddenClass
4051 * @see Class##hiddenClasses Hidden Classes
4052 */
4053 @IntrinsicCandidate
4054 public native boolean isHidden();
4055
4056 /**
4057 * Returns an array containing {@code Class} objects representing the
4058 * direct subinterfaces or subclasses permitted to extend or
4059 * implement this class or interface if it is sealed. The order of such elements
4060 * is unspecified. The array is empty if this sealed class or interface has no
4061 * permitted subclass. If this {@code Class} object represents a primitive type,
4062 * {@code void}, an array type, or a class or interface that is not sealed,
4063 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4064 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4065 * returns a non-null value.
4066 *
4067 * For each class or interface {@code C} which is recorded as a permitted
4068 * direct subinterface or subclass of this class or interface,
4069 * this method attempts to obtain the {@code Class}
4070 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4071 * loader} of the current {@code Class} object).
4072 * The {@code Class} objects which can be obtained and which are direct
4073 * subinterfaces or subclasses of this class or interface,
4074 * are indicated by elements of the returned array. If a {@code Class} object
4075 * cannot be obtained, it is silently ignored, and not included in the result
4076 * array.
4077 *
4078 * @return an array of {@code Class} objects of the permitted subclasses of this class
4079 * or interface, or {@code null} if this class or interface is not sealed.
4080 *
4081 * @jls 8.1 Class Declarations
4082 * @jls 9.1 Interface Declarations
4083 * @since 17
4084 */
4085 public Class<?>[] getPermittedSubclasses() {
4086 Class<?>[] subClasses;
4087 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4088 return null;
4089 }
4090 if (subClasses.length > 0) {
4091 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4092 subClasses = Arrays.stream(subClasses)
4093 .filter(this::isDirectSubType)
4094 .toArray(s -> new Class<?>[s]);
4095 }
4096 }
4097 return subClasses;
4098 }
4099
4100 private boolean isDirectSubType(Class<?> c) {
4101 if (isInterface()) {
4102 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4103 if (i == this) {
4104 return true;
4105 }
4106 }
4107 } else {
4108 return c.getSuperclass() == this;
4109 }
4110 return false;
4111 }
4112
4113 /**
4114 * Returns {@code true} if and only if this {@code Class} object represents
4115 * a sealed class or interface. If this {@code Class} object represents a
4116 * primitive type, {@code void}, or an array type, this method returns
4117 * {@code false}. A sealed class or interface has (possibly zero) permitted
4118 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4119 * possibly empty value for a sealed class or interface.
4120 *
4121 * @return {@code true} if and only if this {@code Class} object represents
4122 * a sealed class or interface.
4123 *
4124 * @jls 8.1 Class Declarations
4125 * @jls 9.1 Interface Declarations
4126 * @since 17
4127 */
4128 public boolean isSealed() {
4129 if (isArray() || isPrimitive()) {
4130 return false;
4131 }
4132 return getPermittedSubclasses() != null;
4133 }
4134
4135 private native Class<?>[] getPermittedSubclasses0();
4136
4137 /*
4138 * Return the class's major and minor class file version packed into an int.
4139 * The high order 16 bits contain the class's minor version. The low order
4140 * 16 bits contain the class's major version.
4141 *
4142 * If the class is an array type then the class file version of its element
4143 * type is returned. If the class is a primitive type then the latest class
4144 * file major version is returned and zero is returned for the minor version.
4145 */
4146 private int getClassFileVersion() {
4147 Class<?> c = isArray() ? elementType() : this;
4148 return c.getClassFileVersion0();
4149 }
4150
4151 private native int getClassFileVersion0();
4152
4153 /*
4154 * Return the access flags as they were in the class's bytecode, including
4155 * the original setting of ACC_SUPER.
4156 *
4157 * If the class is an array type then the access flags of the element type is
4158 * returned. If the class is a primitive then ACC_ABSTRACT | ACC_FINAL | ACC_PUBLIC.
4159 */
4160 private int getClassAccessFlagsRaw() {
4161 Class<?> c = isArray() ? elementType() : this;
4162 return c.getClassAccessFlagsRaw0();
4163 }
4164
4165 private native int getClassAccessFlagsRaw0();
4166
4167 // Support for "OLD" CDS workflow -- {
4168 private static final int RD_PUBLIC_METHODS = (1 << 0);
4169 private static final int RD_PUBLIC_FIELDS = (1 << 1);
4170 private static final int RD_DECLARED_CTORS = (1 << 2);
4171 private static final int RD_PUBLIC_CTORS = (1 << 3);
4172 private static final int RD_DECLARED_METHODS = (1 << 4);
4173 private static final int RD_DECLARED_PUBLIC_METHODS = (1 << 5);
4174 private static final int RD_DECLARED_FIELDS = (1 << 6);
4175 private static final int RD_DECLARED_PUBLIC_FIELDS = (1 << 7);
4176 private static final int RD_DECLARED_INTERFACES = (1 << 8);
4177 private static final int RD_DECLARED_SIMPLE_NAME = (1 << 9);
4178 private static final int RD_DECLARED_CANONICAL_NAME = (1 << 10);
4179 private static final int CLS_NAME = (1 << 10);
4180
4181
4182 private int encodeReflectionData() {
4183 int flags = CLS_NAME;
4184 if (reflectionData != null) {
4185 flags = (reflectionData.publicMethods != null ? RD_PUBLIC_METHODS : 0) |
4186 (reflectionData.publicFields != null ? RD_PUBLIC_FIELDS : 0) |
4187 (reflectionData.declaredConstructors != null ? RD_DECLARED_CTORS : 0) |
4188 (reflectionData.publicConstructors != null ? RD_PUBLIC_CTORS : 0) |
4189 (reflectionData.declaredMethods != null ? RD_DECLARED_METHODS : 0) |
4190 (reflectionData.declaredPublicMethods != null ? RD_DECLARED_PUBLIC_METHODS : 0) |
4191 (reflectionData.declaredFields != null ? RD_DECLARED_FIELDS : 0) |
4192 (reflectionData.declaredPublicFields != null ? RD_DECLARED_PUBLIC_FIELDS : 0) |
4193 (reflectionData.interfaces != null ? RD_DECLARED_INTERFACES : 0) |
4194 (reflectionData.simpleName != null ? RD_DECLARED_SIMPLE_NAME : 0) |
4195 (reflectionData.canonicalName != null ? RD_DECLARED_CANONICAL_NAME : 0);
4196 }
4197 return flags;
4198 }
4199 private void generateReflectionData(int flags) {
4200 if ((flags & CLS_NAME ) != 0) { getName(); } // String name
4201 if ((flags & RD_PUBLIC_METHODS ) != 0) { privateGetPublicMethods(); } // Method[] publicMethods;
4202 if ((flags & RD_PUBLIC_FIELDS ) != 0) { privateGetPublicFields(); } // Field[] publicFields;
4203 if ((flags & RD_DECLARED_CTORS ) != 0) { privateGetDeclaredConstructors(false); } // Constructor<T>[] declaredConstructors;
4204 if ((flags & RD_PUBLIC_CTORS ) != 0) { privateGetDeclaredConstructors(true); } // Constructor<T>[] publicConstructors;
4205 if ((flags & RD_DECLARED_METHODS ) != 0) { privateGetDeclaredMethods(false); } // Method[] declaredMethods;
4206 if ((flags & RD_DECLARED_PUBLIC_METHODS) != 0) { privateGetDeclaredMethods(true); } // Method[] declaredPublicMethods;
4207 if ((flags & RD_DECLARED_FIELDS ) != 0) { privateGetDeclaredFields(false); } // Field[] declaredFields;
4208 if ((flags & RD_DECLARED_PUBLIC_FIELDS ) != 0) { privateGetDeclaredFields(true); } // Field[] declaredPublicFields;
4209 if ((flags & RD_DECLARED_INTERFACES ) != 0) { getInterfaces(false); } // Class<?>[] interfaces;
4210 if ((flags & RD_DECLARED_SIMPLE_NAME ) != 0) { getSimpleName(); } // String simpleName;
4211 if ((flags & RD_DECLARED_CANONICAL_NAME) != 0) { getCanonicalName(); } // String canonicalName;
4212 }
4213
4214 // -- }
4215 }