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.GenericSignatureFormatError;
47 import java.lang.reflect.InvocationTargetException;
48 import java.lang.reflect.Member;
49 import java.lang.reflect.Method;
50 import java.lang.reflect.Modifier;
51 import java.lang.reflect.RecordComponent;
52 import java.lang.reflect.Type;
53 import java.lang.reflect.TypeVariable;
54 import java.lang.constant.Constable;
55 import java.net.URL;
56 import java.security.AllPermission;
57 import java.security.Permissions;
58 import java.security.ProtectionDomain;
59 import java.util.ArrayList;
60 import java.util.Arrays;
61 import java.util.Collection;
62 import java.util.HashMap;
63 import java.util.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.util.ModifiedUtf;
83 import jdk.internal.vm.annotation.AOTRuntimeSetup;
84 import jdk.internal.vm.annotation.AOTSafeClassInitializer;
85 import jdk.internal.vm.annotation.IntrinsicCandidate;
86 import jdk.internal.vm.annotation.Stable;
87
88 import sun.invoke.util.BytecodeDescriptor;
89 import sun.invoke.util.Wrapper;
90 import sun.reflect.generics.factory.CoreReflectionFactory;
91 import sun.reflect.generics.factory.GenericsFactory;
92 import sun.reflect.generics.repository.ClassRepository;
93 import sun.reflect.generics.scope.ClassScope;
94 import sun.reflect.annotation.*;
95
96 /**
97 * Instances of the class {@code Class} represent classes and
98 * interfaces in a running Java application. An enum class and a record
99 * class are kinds of class; an annotation interface is a kind of
100 * interface. Every array also belongs to a class that is reflected as
101 * a {@code Class} object that is shared by all arrays with the same
102 * element type and number of dimensions. The primitive Java types
103 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
104 * int}, {@code long}, {@code float}, and {@code double}), and the
105 * keyword {@code void} are also represented as {@code Class} objects.
106 *
107 * <p> {@code Class} has no public constructor. Instead a {@code Class}
108 * object is constructed automatically by the Java Virtual Machine when
109 * a class is derived from the bytes of a {@code class} file through
110 * the invocation of one of the following methods:
111 * <ul>
112 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
113 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
114 * java.lang.invoke.MethodHandles.Lookup::defineClass}
115 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
116 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
117 * </ul>
118 *
119 * <p> The methods of class {@code Class} expose many characteristics of a
120 * class or interface. Most characteristics are derived from the {@code class}
121 * file that the class loader passed to the Java Virtual Machine or
122 * from the {@code class} file passed to {@code Lookup::defineClass}
123 * or {@code Lookup::defineHiddenClass}.
124 * A few characteristics are determined by the class loading environment
125 * at run time, such as the module returned by {@link #getModule() getModule()}.
126 *
127 * <p> The following example uses a {@code Class} object to print the
128 * class name of an object:
129 *
130 * {@snippet lang="java" :
131 * void printClassName(Object obj) {
132 * System.out.println("The class of " + obj +
133 * " is " + obj.getClass().getName());
134 * }}
135 *
136 * It is also possible to get the {@code Class} object for a named
137 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
138 * (JLS {@jls 15.8.2}).
139 * For example:
140 *
141 * {@snippet lang="java" :
142 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
143 * }
144 *
145 * <p> Some methods of class {@code Class} expose whether the declaration of
146 * a class or interface in Java source code was <em>enclosed</em> within
147 * another declaration. Other methods describe how a class or interface
148 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
149 * classes and interfaces, in the same run-time package, that
150 * allow mutual access to their {@code private} members.
151 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
152 * (JVMS {@jvms 4.7.29}).
153 * One nestmate acts as the
154 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
155 * belong to the nest; each of them in turn records it as the nest host.
156 * The classes and interfaces which belong to a nest, including its host, are
157 * determined when
158 * {@code class} files are generated, for example, a Java compiler
159 * will typically record a top-level class as the host of a nest where the
160 * other members are the classes and interfaces whose declarations are
161 * enclosed within the top-level class declaration.
162 *
163 * <p> Unless otherwise specified, methods in this class throw a
164 * {@link NullPointerException} when they are called with {@code null}
165 * or an array that contains {@code null} as an argument.
166 *
167 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
168 * A class or interface created by the invocation of
169 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
170 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
171 * class or interface.
172 * All kinds of class, including enum classes and record classes, may be
173 * hidden classes; all kinds of interface, including annotation interfaces,
174 * may be hidden interfaces.
175 *
176 * The {@linkplain #getName() name of a hidden class or interface} is
177 * not a {@linkplain ClassLoader##binary-name binary name},
178 * which means the following:
179 * <ul>
180 * <li>A hidden class or interface cannot be referenced by the constant pools
181 * of other classes and interfaces.
182 * <li>A hidden class or interface cannot be described in
183 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
184 * {@link #describeConstable() Class::describeConstable},
185 * {@link ClassDesc#of(String) ClassDesc::of}, or
186 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
187 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
188 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
189 * </ul>
190 *
191 * A hidden class or interface is never an array class, but may be
192 * the element type of an array. In all other respects, the fact that
193 * a class or interface is hidden has no bearing on the characteristics
194 * exposed by the methods of class {@code Class}.
195 *
196 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
197 *
198 * Conventionally, a Java compiler, starting from a source file for an
199 * implicitly declared class, say {@code HelloWorld.java}, creates a
200 * similarly-named {@code class} file, {@code HelloWorld.class}, where
201 * the class stored in that {@code class} file is named {@code
202 * "HelloWorld"}, matching the base names of the source and {@code
203 * class} files.
204 *
205 * For the {@code Class} object of an implicitly declared class {@code
206 * HelloWorld}, the methods to get the {@linkplain #getName name} and
207 * {@linkplain #getTypeName type name} return results
208 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
209 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
210 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
211 *
212 * @param <T> the type of the class modeled by this {@code Class}
213 * object. For example, the type of {@code String.class} is {@code
214 * Class<String>}. Use {@code Class<?>} if the class being modeled is
215 * unknown.
216 *
217 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
218 * @since 1.0
219 */
220 @AOTSafeClassInitializer
221 public final class Class<T> implements java.io.Serializable,
222 GenericDeclaration,
223 Type,
224 AnnotatedElement,
225 TypeDescriptor.OfField<Class<?>>,
226 Constable {
227 private static final int ANNOTATION= 0x00002000;
228 private static final int ENUM = 0x00004000;
229 private static final int SYNTHETIC = 0x00001000;
230
231 private static native void registerNatives();
232 static {
233 runtimeSetup();
234 }
235
236 /// No significant static final fields; [#resetArchivedStates()] handles
237 /// prevents storing [#reflectionFactory] into AOT image.
238 @AOTRuntimeSetup
239 private static void runtimeSetup() {
240 registerNatives();
241 }
242
243 /*
244 * Private constructor. Only the Java Virtual Machine creates Class objects.
245 * This constructor is not used and prevents the default constructor being
246 * generated.
247 */
248 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, char flags) {
249 // Initialize final field for classLoader. The initialization value of non-null
250 // prevents future JIT optimizations from assuming this final field is null.
251 // The following assignments are done directly by the VM without calling this constructor.
252 classLoader = loader;
253 componentType = arrayComponentType;
254 modifiers = mods;
255 protectionDomain = pd;
256 primitive = isPrim;
257 classFileAccessFlags = flags;
258 }
259
260 /**
261 * Converts the object to a string. The string representation is the
262 * string "class" or "interface", followed by a space, and then by the
263 * name of the class in the format returned by {@code getName}.
264 * If this {@code Class} object represents a primitive type,
265 * this method returns the name of the primitive type. If
266 * this {@code Class} object represents void this method returns
267 * "void". If this {@code Class} object represents an array type,
268 * this method returns "class " followed by {@code getName}.
269 *
270 * @return a string representation of this {@code Class} object.
271 */
272 public String toString() {
273 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
274 return kind.concat(getName());
275 }
276
277 /**
278 * Returns a string describing this {@code Class}, including
279 * information about modifiers, {@link #isSealed() sealed}/{@code
280 * non-sealed} status, and type parameters.
281 *
282 * The string is formatted as a list of type modifiers, if any,
283 * followed by the kind of type (empty string for primitive types
284 * and {@code class}, {@code enum}, {@code interface},
285 * {@code @interface}, or {@code record} as appropriate), followed
286 * by the type's name, followed by an angle-bracketed
287 * comma-separated list of the type's type parameters, if any,
288 * including informative bounds on the type parameters, if any.
289 *
290 * A space is used to separate modifiers from one another and to
291 * separate any modifiers from the kind of type. The modifiers
292 * occur in canonical order. If there are no type parameters, the
293 * type parameter list is elided.
294 *
295 * For an array type, the string starts with the type name,
296 * followed by an angle-bracketed comma-separated list of the
297 * type's type parameters, if any, followed by a sequence of
298 * {@code []} characters, one set of brackets per dimension of
299 * the array.
300 *
301 * <p>Note that since information about the runtime representation
302 * of a type is being generated, modifiers not present on the
303 * originating source code or illegal on the originating source
304 * code may be present.
305 *
306 * @return a string describing this {@code Class}, including
307 * information about modifiers and type parameters
308 *
309 * @since 1.8
310 */
311 public String toGenericString() {
312 if (isPrimitive()) {
313 return toString();
314 } else {
315 StringBuilder sb = new StringBuilder();
316 Class<?> component = this;
317 int arrayDepth = 0;
318
319 if (isArray()) {
320 do {
321 arrayDepth++;
322 component = component.getComponentType();
323 } while (component.isArray());
324 sb.append(component.getName());
325 } else {
326 // Class modifiers are a superset of interface modifiers
327 int modifiers = getModifiers() & Modifier.classModifiers();
328 if (modifiers != 0) {
329 sb.append(Modifier.toString(modifiers));
330 sb.append(' ');
331 }
332
333 // A class cannot be strictfp and sealed/non-sealed so
334 // it is sufficient to check for sealed-ness after all
335 // modifiers are printed.
336 addSealingInfo(modifiers, sb);
337
338 if (isAnnotation()) {
339 sb.append('@');
340 }
341 if (isInterface()) { // Note: all annotation interfaces are interfaces
342 sb.append("interface");
343 } else {
344 if (isEnum())
345 sb.append("enum");
346 else if (isRecord())
347 sb.append("record");
348 else
349 sb.append("class");
350 }
351 sb.append(' ');
352 sb.append(getName());
353 }
354
355 TypeVariable<?>[] typeparms = component.getTypeParameters();
356 if (typeparms.length > 0) {
357 sb.append(Arrays.stream(typeparms)
358 .map(Class::typeVarBounds)
359 .collect(Collectors.joining(",", "<", ">")));
360 }
361
362 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
363
364 return sb.toString();
365 }
366 }
367
368 private void addSealingInfo(int modifiers, StringBuilder sb) {
369 // A class can be final XOR sealed XOR non-sealed.
370 if (Modifier.isFinal(modifiers)) {
371 return; // no-op
372 } else {
373 if (isSealed()) {
374 sb.append("sealed ");
375 return;
376 } else {
377 // Check for sealed ancestor, which implies this class
378 // is non-sealed.
379 if (hasSealedAncestor(this)) {
380 sb.append("non-sealed ");
381 }
382 }
383 }
384 }
385
386 private boolean hasSealedAncestor(Class<?> clazz) {
387 // From JLS 8.1.1.2:
388 // "It is a compile-time error if a class has a sealed direct
389 // superclass or a sealed direct superinterface, and is not
390 // declared final, sealed, or non-sealed either explicitly or
391 // implicitly.
392 // Thus, an effect of the sealed keyword is to force all
393 // direct subclasses to explicitly declare whether they are
394 // final, sealed, or non-sealed. This avoids accidentally
395 // exposing a sealed class hierarchy to unwanted subclassing."
396
397 // Therefore, will just check direct superclass and
398 // superinterfaces.
399 var superclass = clazz.getSuperclass();
400 if (superclass != null && superclass.isSealed()) {
401 return true;
402 }
403 for (var superinterface : clazz.getInterfaces()) {
404 if (superinterface.isSealed()) {
405 return true;
406 }
407 }
408 return false;
409 }
410
411 static String typeVarBounds(TypeVariable<?> typeVar) {
412 Type[] bounds = typeVar.getBounds();
413 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
414 return typeVar.getName();
415 } else {
416 return typeVar.getName() + " extends " +
417 Arrays.stream(bounds)
418 .map(Type::getTypeName)
419 .collect(Collectors.joining(" & "));
420 }
421 }
422
423 /**
424 * Returns the {@code Class} object associated with the class or
425 * interface with the given string name. Invoking this method is
426 * equivalent to:
427 *
428 * {@snippet lang="java" :
429 * Class.forName(className, true, currentLoader)
430 * }
431 *
432 * where {@code currentLoader} denotes the defining class loader of
433 * the current class.
434 *
435 * <p> For example, the following code fragment returns the
436 * runtime {@code Class} object for the class named
437 * {@code java.lang.Thread}:
438 *
439 * {@snippet lang="java" :
440 * Class<?> t = Class.forName("java.lang.Thread");
441 * }
442 * <p>
443 * A call to {@code forName("X")} causes the class named
444 * {@code X} to be initialized.
445 *
446 * <p>
447 * In cases where this method is called from a context where there is no
448 * caller frame on the stack (e.g. when called directly from a JNI
449 * attached thread), the system class loader is used.
450 *
451 * @param className the {@linkplain ClassLoader##binary-name binary name}
452 * of the class or the string representing an array type
453 * @return the {@code Class} object for the class with the
454 * specified name.
455 * @throws LinkageError if the linkage fails
456 * @throws ExceptionInInitializerError if the initialization provoked
457 * by this method fails
458 * @throws ClassNotFoundException if the class cannot be located
459 *
460 * @jls 12.2 Loading of Classes and Interfaces
461 * @jls 12.3 Linking of Classes and Interfaces
462 * @jls 12.4 Initialization of Classes and Interfaces
463 */
464 @CallerSensitive
465 public static Class<?> forName(String className)
466 throws ClassNotFoundException {
467 Class<?> caller = Reflection.getCallerClass();
468 return forName(className, caller);
469 }
470
471 // Caller-sensitive adapter method for reflective invocation
472 @CallerSensitiveAdapter
473 private static Class<?> forName(String className, Class<?> caller)
474 throws ClassNotFoundException {
475 validateClassNameLength(className);
476 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
477 : ClassLoader.getClassLoader(caller);
478 if (loader instanceof BuiltinClassLoader bcl) {
479 if (bcl.usePositiveCache) {
480 Class<?> result = bcl.checkPositiveLookupCache(className);
481 if (result != null) {
482 // forName(String, Class) API will always initialize the class
483 Unsafe.getUnsafe().ensureClassInitialized(result);
484 return result;
485 }
486 }
487 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(className)) {
488 throw new ClassNotFoundException(className);
489 }
490 }
491 return forName0(className, true, loader);
492 }
493
494 /**
495 * Returns the {@code Class} object associated with the class or
496 * interface with the given string name, using the given class loader.
497 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
498 * this method attempts to locate and load the class or interface. The specified
499 * class loader is used to load the class or interface. If the parameter
500 * {@code loader} is {@code null}, the class is loaded through the bootstrap
501 * class loader. The class is initialized only if the
502 * {@code initialize} parameter is {@code true} and if it has
503 * not been initialized earlier.
504 *
505 * <p> This method cannot be used to obtain any of the {@code Class} objects
506 * representing primitive types or void, hidden classes or interfaces,
507 * or array classes whose element type is a hidden class or interface.
508 * If {@code name} denotes a primitive type or void, for example {@code I},
509 * an attempt will be made to locate a user-defined class in the unnamed package
510 * whose name is {@code I} instead.
511 * To obtain a {@code Class} object for a named primitive type
512 * such as {@code int} or {@code long} use {@link
513 * #forPrimitiveName(String)}.
514 *
515 * <p> To obtain the {@code Class} object associated with an array class,
516 * the name consists of one or more {@code '['} representing the depth
517 * of the array nesting, followed by the element type as encoded in
518 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
519 *
520 * <p> Examples:
521 * {@snippet lang="java" :
522 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
523 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
524 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
525 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
526 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
527 * }
528 *
529 * <p> A call to {@code getName()} on the {@code Class} object returned
530 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
531 *
532 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
533 * named <i>N</i> to be loaded but not initialized regardless of the value
534 * of the {@code initialize} parameter.
535 *
536 * @apiNote
537 * This method throws errors related to loading, linking or initializing
538 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
539 * <cite>The Java Language Specification</cite>.
540 * In addition, this method does not check whether the requested class
541 * is accessible to its caller.
542 *
543 * @param name the {@linkplain ClassLoader##binary-name binary name}
544 * of the class or the string representing an array class
545 *
546 * @param initialize if {@code true} the class will be initialized
547 * (which implies linking). See Section {@jls
548 * 12.4} of <cite>The Java Language
549 * Specification</cite>.
550 * @param loader class loader from which the class must be loaded,
551 * may be {@code null}
552 * @return class object representing the desired class
553 *
554 * @throws LinkageError if the linkage fails
555 * @throws ExceptionInInitializerError if the initialization provoked
556 * by this method fails
557 * @throws ClassNotFoundException if the class cannot be located by
558 * the specified class loader
559 *
560 * @see java.lang.Class#forName(String)
561 * @see java.lang.ClassLoader
562 *
563 * @jls 12.2 Loading of Classes and Interfaces
564 * @jls 12.3 Linking of Classes and Interfaces
565 * @jls 12.4 Initialization of Classes and Interfaces
566 * @jls 13.1 The Form of a Binary
567 * @since 1.2
568 */
569 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
570 throws ClassNotFoundException
571 {
572 validateClassNameLength(name);
573
574 if (loader instanceof BuiltinClassLoader bcl) {
575 if (bcl.usePositiveCache) {
576 Class<?> result = bcl.checkPositiveLookupCache(name);
577 if (result != null) {
578 if (initialize) {
579 Unsafe.getUnsafe().ensureClassInitialized(result);
580 }
581 return result;
582 }
583 }
584 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(name)) {
585 throw new ClassNotFoundException(name);
586 }
587 }
588
589 return forName0(name, initialize, loader);
590 }
591
592 /** Called after security check for system loader access checks have been made. */
593 private static native Class<?> forName0(String name, boolean initialize,
594 ClassLoader loader)
595 throws ClassNotFoundException;
596
597
598 /**
599 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
600 * binary name} in the given module.
601 *
602 * <p> This method attempts to locate and load the class or interface.
603 * It does not link the class, and does not run the class initializer.
604 * If the class is not found, this method returns {@code null}. </p>
605 *
606 * <p> If the class loader of the given module defines other modules and
607 * the given name is a class defined in a different module, this method
608 * returns {@code null} after the class is loaded. </p>
609 *
610 * <p> This method does not check whether the requested class is
611 * accessible to its caller. </p>
612 *
613 * @apiNote
614 * This method does not support loading of array types, unlike
615 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
616 * a binary name. This method returns {@code null} on failure rather than
617 * throwing a {@link ClassNotFoundException}, as is done by
618 * the {@link #forName(String, boolean, ClassLoader)} method.
619 *
620 * @param module A module
621 * @param name The {@linkplain ClassLoader##binary-name binary name}
622 * of the class
623 * @return {@code Class} object of the given name defined in the given module;
624 * {@code null} if not found.
625 *
626 * @throws LinkageError if the linkage fails
627 *
628 * @jls 12.2 Loading of Classes and Interfaces
629 * @jls 12.3 Linking of Classes and Interfaces
630 * @since 9
631 */
632 public static Class<?> forName(Module module, String name) {
633 Objects.requireNonNull(module);
634 Objects.requireNonNull(name);
635 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
636 return null;
637 }
638
639 ClassLoader cl = module.getClassLoader();
640 if (cl != null) {
641 return cl.loadClass(module, name);
642 } else {
643 return BootLoader.loadClass(module, name);
644 }
645 }
646
647 /**
648 * {@return the {@code Class} object associated with the
649 * {@linkplain #isPrimitive() primitive type} of the given name}
650 * If the argument is not the name of a primitive type, {@code
651 * null} is returned.
652 *
653 * @param primitiveName the name of the primitive type to find
654 *
655 * @jls 4.2 Primitive Types and Values
656 * @jls 15.8.2 Class Literals
657 * @since 22
658 */
659 public static Class<?> forPrimitiveName(String primitiveName) {
660 return switch(primitiveName) {
661 // Integral types
662 case "int" -> int.class;
663 case "long" -> long.class;
664 case "short" -> short.class;
665 case "char" -> char.class;
666 case "byte" -> byte.class;
667
668 // Floating-point types
669 case "float" -> float.class;
670 case "double" -> double.class;
671
672 // Other types
673 case "boolean" -> boolean.class;
674 case "void" -> void.class;
675
676 default -> null;
677 };
678 }
679
680 /**
681 * Creates a new instance of the class represented by this {@code Class}
682 * object. The class is instantiated as if by a {@code new}
683 * expression with an empty argument list. The class is initialized if it
684 * has not already been initialized.
685 *
686 * @deprecated This method propagates any exception thrown by the
687 * nullary constructor, including a checked exception. Use of
688 * this method effectively bypasses the compile-time exception
689 * checking that would otherwise be performed by the compiler.
690 * The {@link
691 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
692 * Constructor.newInstance} method avoids this problem by wrapping
693 * any exception thrown by the constructor in a (checked) {@link
694 * java.lang.reflect.InvocationTargetException}.
695 *
696 * <p>The call
697 *
698 * {@snippet lang="java" :
699 * clazz.newInstance()
700 * }
701 *
702 * can be replaced by
703 *
704 * {@snippet lang="java" :
705 * clazz.getDeclaredConstructor().newInstance()
706 * }
707 *
708 * The latter sequence of calls is inferred to be able to throw
709 * the additional exception types {@link
710 * InvocationTargetException} and {@link
711 * NoSuchMethodException}. Both of these exception types are
712 * subclasses of {@link ReflectiveOperationException}.
713 *
714 * @return a newly allocated instance of the class represented by this
715 * object.
716 * @throws IllegalAccessException if the class or its nullary
717 * constructor is not accessible.
718 * @throws InstantiationException
719 * if this {@code Class} represents an abstract class,
720 * an interface, an array class, a primitive type, or void;
721 * or if the class has no nullary constructor;
722 * or if the instantiation fails for some other reason.
723 * @throws ExceptionInInitializerError if the initialization
724 * provoked by this method fails.
725 */
726 @CallerSensitive
727 @Deprecated(since="9")
728 public T newInstance()
729 throws InstantiationException, IllegalAccessException
730 {
731 // Constructor lookup
732 Constructor<T> tmpConstructor = cachedConstructor;
733 if (tmpConstructor == null) {
734 if (this == Class.class) {
735 throw new IllegalAccessException(
736 "Can not call newInstance() on the Class for java.lang.Class"
737 );
738 }
739 try {
740 Class<?>[] empty = {};
741 final Constructor<T> c = getReflectionFactory().copyConstructor(
742 getConstructor0(empty, Member.DECLARED));
743 // Disable accessibility checks on the constructor
744 // access check is done with the true caller
745 c.setAccessible(true);
746 cachedConstructor = tmpConstructor = c;
747 } catch (NoSuchMethodException e) {
748 throw (InstantiationException)
749 new InstantiationException(getName()).initCause(e);
750 }
751 }
752
753 try {
754 Class<?> caller = Reflection.getCallerClass();
755 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
756 } catch (InvocationTargetException e) {
757 Unsafe.getUnsafe().throwException(e.getTargetException());
758 // Not reached
759 return null;
760 }
761 }
762
763 private transient volatile Constructor<T> cachedConstructor;
764
765 /**
766 * Determines if the specified {@code Object} is assignment-compatible
767 * with the object represented by this {@code Class}. This method is
768 * the dynamic equivalent of the Java language {@code instanceof}
769 * operator. The method returns {@code true} if the specified
770 * {@code Object} argument is non-null and can be cast to the
771 * reference type represented by this {@code Class} object without
772 * raising a {@code ClassCastException.} It returns {@code false}
773 * otherwise.
774 *
775 * <p> Specifically, if this {@code Class} object represents a
776 * declared class, this method returns {@code true} if the specified
777 * {@code Object} argument is an instance of the represented class (or
778 * of any of its subclasses); it returns {@code false} otherwise. If
779 * this {@code Class} object represents an array class, this method
780 * returns {@code true} if the specified {@code Object} argument
781 * can be converted to an object of the array class by an identity
782 * conversion or by a widening reference conversion; it returns
783 * {@code false} otherwise. If this {@code Class} object
784 * represents an interface, this method returns {@code true} if the
785 * class or any superclass of the specified {@code Object} argument
786 * implements this interface; it returns {@code false} otherwise. If
787 * this {@code Class} object represents a primitive type, this method
788 * returns {@code false}.
789 *
790 * @param obj the object to check, may be {@code null}
791 * @return true if {@code obj} is an instance of this class
792 *
793 * @since 1.1
794 */
795 @IntrinsicCandidate
796 public native boolean isInstance(Object obj);
797
798
799 /**
800 * Determines if the class or interface represented by this
801 * {@code Class} object is either the same as, or is a superclass or
802 * superinterface of, the class or interface represented by the specified
803 * {@code Class} parameter. It returns {@code true} if so;
804 * otherwise it returns {@code false}. If this {@code Class}
805 * object represents a primitive type, this method returns
806 * {@code true} if the specified {@code Class} parameter is
807 * exactly this {@code Class} object; otherwise it returns
808 * {@code false}.
809 *
810 * <p> Specifically, this method tests whether the type represented by the
811 * specified {@code Class} parameter can be converted to the type
812 * represented by this {@code Class} object via an identity conversion
813 * or via a widening reference conversion. See <cite>The Java Language
814 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
815 * for details.
816 *
817 * @param cls the {@code Class} object to be checked
818 * @return the {@code boolean} value indicating whether objects of the
819 * type {@code cls} can be assigned to objects of this class
820 * @since 1.1
821 */
822 @IntrinsicCandidate
823 public native boolean isAssignableFrom(Class<?> cls);
824
825
826 /**
827 * Determines if this {@code Class} object represents an
828 * interface type.
829 *
830 * @return {@code true} if this {@code Class} object represents an interface;
831 * {@code false} otherwise.
832 */
833 public boolean isInterface() {
834 return Modifier.isInterface(modifiers);
835 }
836
837
838 /**
839 * Determines if this {@code Class} object represents an array class.
840 *
841 * @return {@code true} if this {@code Class} object represents an array class;
842 * {@code false} otherwise.
843 * @since 1.1
844 */
845 public boolean isArray() {
846 return componentType != null;
847 }
848
849
850 /**
851 * Determines if this {@code Class} object represents a primitive
852 * type or void.
853 *
854 * <p> There are nine predefined {@code Class} objects to
855 * represent the eight primitive types and void. These are
856 * created by the Java Virtual Machine, and have the same
857 * {@linkplain #getName() names} as the primitive types that they
858 * represent, namely {@code boolean}, {@code byte}, {@code char},
859 * {@code short}, {@code int}, {@code long}, {@code float}, and
860 * {@code double}.
861 *
862 * <p>No other class objects are considered primitive.
863 *
864 * @apiNote
865 * A {@code Class} object represented by a primitive type can be
866 * accessed via the {@code TYPE} public static final variables
867 * defined in the primitive wrapper classes such as {@link
868 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
869 * language, the objects may be referred to by a class literal
870 * expression such as {@code int.class}. The {@code Class} object
871 * for void can be expressed as {@code void.class} or {@link
872 * java.lang.Void#TYPE Void.TYPE}.
873 *
874 * @return true if and only if this class represents a primitive type
875 *
876 * @see java.lang.Boolean#TYPE
877 * @see java.lang.Character#TYPE
878 * @see java.lang.Byte#TYPE
879 * @see java.lang.Short#TYPE
880 * @see java.lang.Integer#TYPE
881 * @see java.lang.Long#TYPE
882 * @see java.lang.Float#TYPE
883 * @see java.lang.Double#TYPE
884 * @see java.lang.Void#TYPE
885 * @since 1.1
886 * @jls 15.8.2 Class Literals
887 */
888 public boolean isPrimitive() {
889 return primitive;
890 }
891
892 /**
893 * Returns true if this {@code Class} object represents an annotation
894 * interface. Note that if this method returns true, {@link #isInterface()}
895 * would also return true, as all annotation interfaces are also interfaces.
896 *
897 * @return {@code true} if this {@code Class} object represents an annotation
898 * interface; {@code false} otherwise
899 * @since 1.5
900 */
901 public boolean isAnnotation() {
902 return (getModifiers() & ANNOTATION) != 0;
903 }
904
905 /**
906 *{@return {@code true} if and only if this class has the synthetic modifier
907 * bit set}
908 *
909 * @jls 13.1 The Form of a Binary
910 * @jvms 4.1 The {@code ClassFile} Structure
911 * @see <a
912 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
913 * programming language and JVM modeling in core reflection</a>
914 * @since 1.5
915 */
916 public boolean isSynthetic() {
917 return (getModifiers() & SYNTHETIC) != 0;
918 }
919
920 /**
921 * Returns the name of the entity (class, interface, array class,
922 * primitive type, or void) represented by this {@code Class} object.
923 *
924 * <p> If this {@code Class} object represents a class or interface,
925 * not an array class, then:
926 * <ul>
927 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
928 * then the {@linkplain ClassLoader##binary-name binary name}
929 * of the class or interface is returned.
930 * <li> If the class or interface is hidden, then the result is a string
931 * of the form: {@code N + '/' + <suffix>}
932 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
933 * indicated by the {@code class} file passed to
934 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
935 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
936 * </ul>
937 *
938 * <p> If this {@code Class} object represents an array class, then
939 * the result is a string consisting of one or more '{@code [}' characters
940 * representing the depth of the array nesting, followed by the element
941 * type as encoded using the following table:
942 *
943 * <blockquote><table class="striped" id="nameFormat">
944 * <caption style="display:none">Element types and encodings</caption>
945 * <thead>
946 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
947 * </thead>
948 * <tbody style="text-align:left">
949 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
950 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
951 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
952 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
953 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
954 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
955 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
956 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
957 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
958 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
959 * </tbody>
960 * </table></blockquote>
961 *
962 * <p> If this {@code Class} object represents a primitive type or {@code void},
963 * then the result is a string with the same spelling as the Java language
964 * keyword which corresponds to the primitive type or {@code void}.
965 *
966 * <p> Examples:
967 * <blockquote><pre>
968 * String.class.getName()
969 * returns "java.lang.String"
970 * Character.UnicodeBlock.class.getName()
971 * returns "java.lang.Character$UnicodeBlock"
972 * byte.class.getName()
973 * returns "byte"
974 * (new Object[3]).getClass().getName()
975 * returns "[Ljava.lang.Object;"
976 * (new int[3][4][5][6][7][8][9]).getClass().getName()
977 * returns "[[[[[[[I"
978 * </pre></blockquote>
979 *
980 * @apiNote
981 * Distinct class objects can have the same name but different class loaders.
982 *
983 * @return the name of the class, interface, or other entity
984 * represented by this {@code Class} object.
985 * @jls 13.1 The Form of a Binary
986 */
987 public String getName() {
988 String name = this.name;
989 return name != null ? name : initClassName();
990 }
991
992 // Cache the name to reduce the number of calls into the VM.
993 // This field would be set by VM itself during initClassName call.
994 private transient String name;
995 private native String initClassName();
996
997 /**
998 * Returns the class loader for the class. Some implementations may use
999 * null to represent the bootstrap class loader. This method will return
1000 * null in such implementations if this class was loaded by the bootstrap
1001 * class loader.
1002 *
1003 * <p>If this {@code Class} object
1004 * represents a primitive type or void, null is returned.
1005 *
1006 * @return the class loader that loaded the class or interface
1007 * represented by this {@code Class} object.
1008 * @see java.lang.ClassLoader
1009 */
1010 public ClassLoader getClassLoader() {
1011 return classLoader;
1012 }
1013
1014 // Package-private to allow ClassLoader access
1015 ClassLoader getClassLoader0() { return classLoader; }
1016
1017 /**
1018 * Returns the module that this class or interface is a member of.
1019 *
1020 * If this class represents an array type then this method returns the
1021 * {@code Module} for the element type. If this class represents a
1022 * primitive type or void, then the {@code Module} object for the
1023 * {@code java.base} module is returned.
1024 *
1025 * If this class is in an unnamed module then the {@linkplain
1026 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1027 * loader for this class is returned.
1028 *
1029 * @return the module that this class or interface is a member of
1030 *
1031 * @since 9
1032 */
1033 public Module getModule() {
1034 return module;
1035 }
1036
1037 // set by VM
1038 @Stable
1039 private transient Module module;
1040
1041 // Initialized in JVM not by private constructor
1042 // This field is filtered from reflection access, i.e. getDeclaredField
1043 // will throw NoSuchFieldException
1044 private final ClassLoader classLoader;
1045
1046 private transient Object classData; // Set by VM
1047 private transient Object[] signers; // Read by VM, mutable
1048 private final transient char modifiers; // Set by the VM
1049 private final transient char classFileAccessFlags; // Set by the VM
1050 private final transient boolean primitive; // Set by the VM if the Class is a primitive type.
1051
1052 // package-private
1053 Object getClassData() {
1054 return classData;
1055 }
1056
1057 /**
1058 * Returns an array of {@code TypeVariable} objects that represent the
1059 * type variables declared by the generic declaration represented by this
1060 * {@code GenericDeclaration} object, in declaration order. Returns an
1061 * array of length 0 if the underlying generic declaration declares no type
1062 * variables.
1063 *
1064 * @return an array of {@code TypeVariable} objects that represent
1065 * the type variables declared by this generic declaration
1066 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1067 * signature of this generic declaration does not conform to
1068 * the format specified in section {@jvms 4.7.9} of
1069 * <cite>The Java Virtual Machine Specification</cite>
1070 * @since 1.5
1071 */
1072 @SuppressWarnings("unchecked")
1073 public TypeVariable<Class<T>>[] getTypeParameters() {
1074 ClassRepository info = getGenericInfo();
1075 if (info != null)
1076 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1077 else
1078 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1079 }
1080
1081
1082 /**
1083 * Returns the {@code Class} representing the direct superclass of the
1084 * entity (class, interface, primitive type or void) represented by
1085 * this {@code Class}. If this {@code Class} represents either the
1086 * {@code Object} class, an interface, a primitive type, or void, then
1087 * null is returned. If this {@code Class} object represents an array class
1088 * then the {@code Class} object representing the {@code Object} class is
1089 * returned.
1090 *
1091 * @return the direct superclass of the class represented by this {@code Class} object
1092 */
1093 @IntrinsicCandidate
1094 public native Class<? super T> getSuperclass();
1095
1096
1097 /**
1098 * Returns the {@code Type} representing the direct superclass of
1099 * the entity (class, interface, primitive type or void) represented by
1100 * this {@code Class} object.
1101 *
1102 * <p>If the superclass is a parameterized type, the {@code Type}
1103 * object returned must accurately reflect the actual type
1104 * arguments used in the source code. The parameterized type
1105 * representing the superclass is created if it had not been
1106 * created before. See the declaration of {@link
1107 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1108 * semantics of the creation process for parameterized types. If
1109 * this {@code Class} object represents either the {@code Object}
1110 * class, an interface, a primitive type, or void, then null is
1111 * returned. If this {@code Class} object represents an array class
1112 * then the {@code Class} object representing the {@code Object} class is
1113 * returned.
1114 *
1115 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1116 * class signature does not conform to the format specified in
1117 * section {@jvms 4.7.9} of <cite>The Java Virtual
1118 * Machine Specification</cite>
1119 * @throws TypeNotPresentException if the generic superclass
1120 * refers to a non-existent type declaration
1121 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1122 * generic superclass refers to a parameterized type that cannot be
1123 * instantiated for any reason
1124 * @return the direct superclass of the class represented by this {@code Class} object
1125 * @since 1.5
1126 */
1127 public Type getGenericSuperclass() {
1128 ClassRepository info = getGenericInfo();
1129 if (info == null) {
1130 return getSuperclass();
1131 }
1132
1133 // Historical irregularity:
1134 // Generic signature marks interfaces with superclass = Object
1135 // but this API returns null for interfaces
1136 if (isInterface()) {
1137 return null;
1138 }
1139
1140 return info.getSuperclass();
1141 }
1142
1143 /**
1144 * Gets the package of this class.
1145 *
1146 * <p>If this class represents an array type, a primitive type or void,
1147 * this method returns {@code null}.
1148 *
1149 * @return the package of this class.
1150 */
1151 public Package getPackage() {
1152 if (isPrimitive() || isArray()) {
1153 return null;
1154 }
1155 ClassLoader cl = classLoader;
1156 return cl != null ? cl.definePackage(this)
1157 : BootLoader.definePackage(this);
1158 }
1159
1160 /**
1161 * Returns the fully qualified package name.
1162 *
1163 * <p> If this class is a top level class, then this method returns the fully
1164 * qualified name of the package that the class is a member of, or the
1165 * empty string if the class is in an unnamed package.
1166 *
1167 * <p> If this class is a member class, then this method is equivalent to
1168 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1169 * enclosing class}.
1170 *
1171 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1172 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1173 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1174 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1175 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1176 *
1177 * <p> If this class represents an array type then this method returns the
1178 * package name of the element type. If this class represents a primitive
1179 * type or void then the package name "{@code java.lang}" is returned.
1180 *
1181 * @return the fully qualified package name
1182 *
1183 * @since 9
1184 * @jls 6.7 Fully Qualified Names and Canonical Names
1185 */
1186 public String getPackageName() {
1187 String pn = this.packageName;
1188 if (pn == null) {
1189 Class<?> c = isArray() ? elementType() : this;
1190 if (c.isPrimitive()) {
1191 pn = "java.lang";
1192 } else {
1193 String cn = c.getName();
1194 int dot = cn.lastIndexOf('.');
1195 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1196 }
1197 this.packageName = pn;
1198 }
1199 return pn;
1200 }
1201
1202 // cached package name
1203 private transient String packageName;
1204
1205 /**
1206 * Returns the interfaces directly implemented by the class or interface
1207 * represented by this {@code Class} object.
1208 *
1209 * <p>If this {@code Class} object represents a class, the return value is an array
1210 * containing objects representing all interfaces directly implemented by
1211 * the class. The order of the interface objects in the array corresponds
1212 * to the order of the interface names in the {@code implements} clause of
1213 * the declaration of the class represented by this {@code Class} object. For example,
1214 * given the declaration:
1215 * <blockquote>
1216 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1217 * </blockquote>
1218 * suppose the value of {@code s} is an instance of
1219 * {@code Shimmer}; the value of the expression:
1220 * <blockquote>
1221 * {@code s.getClass().getInterfaces()[0]}
1222 * </blockquote>
1223 * is the {@code Class} object that represents interface
1224 * {@code FloorWax}; and the value of:
1225 * <blockquote>
1226 * {@code s.getClass().getInterfaces()[1]}
1227 * </blockquote>
1228 * is the {@code Class} object that represents interface
1229 * {@code DessertTopping}.
1230 *
1231 * <p>If this {@code Class} object represents an interface, the array contains objects
1232 * representing all interfaces directly extended by the interface. The
1233 * order of the interface objects in the array corresponds to the order of
1234 * the interface names in the {@code extends} clause of the declaration of
1235 * the interface represented by this {@code Class} object.
1236 *
1237 * <p>If this {@code Class} object represents a class or interface that implements no
1238 * interfaces, the method returns an array of length 0.
1239 *
1240 * <p>If this {@code Class} object represents a primitive type or void, the method
1241 * returns an array of length 0.
1242 *
1243 * <p>If this {@code Class} object represents an array type, the
1244 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1245 * returned in that order.
1246 *
1247 * @return an array of interfaces directly implemented by this class
1248 */
1249 public Class<?>[] getInterfaces() {
1250 // defensively copy before handing over to user code
1251 return getInterfaces(true);
1252 }
1253
1254 private Class<?>[] getInterfaces(boolean cloneArray) {
1255 ReflectionData<T> rd = reflectionData();
1256 Class<?>[] interfaces = rd.interfaces;
1257 if (interfaces == null) {
1258 interfaces = getInterfaces0();
1259 rd.interfaces = interfaces;
1260 }
1261 // defensively copy if requested
1262 return cloneArray ? interfaces.clone() : interfaces;
1263 }
1264
1265 private native Class<?>[] getInterfaces0();
1266
1267 /**
1268 * Returns the {@code Type}s representing the interfaces
1269 * directly implemented by the class or interface represented by
1270 * this {@code Class} object.
1271 *
1272 * <p>If a superinterface is a parameterized type, the
1273 * {@code Type} object returned for it must accurately reflect
1274 * the actual type arguments used in the source code. The
1275 * parameterized type representing each superinterface is created
1276 * if it had not been created before. See the declaration of
1277 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1278 * for the semantics of the creation process for parameterized
1279 * types.
1280 *
1281 * <p>If this {@code Class} object represents a class, the return value is an array
1282 * containing objects representing all interfaces directly implemented by
1283 * the class. The order of the interface objects in the array corresponds
1284 * to the order of the interface names in the {@code implements} clause of
1285 * the declaration of the class represented by this {@code Class} object.
1286 *
1287 * <p>If this {@code Class} object represents an interface, the array contains objects
1288 * representing all interfaces directly extended by the interface. The
1289 * order of the interface objects in the array corresponds to the order of
1290 * the interface names in the {@code extends} clause of the declaration of
1291 * the interface represented by this {@code Class} object.
1292 *
1293 * <p>If this {@code Class} object represents a class or interface that implements no
1294 * interfaces, the method returns an array of length 0.
1295 *
1296 * <p>If this {@code Class} object represents a primitive type or void, the method
1297 * returns an array of length 0.
1298 *
1299 * <p>If this {@code Class} object represents an array type, the
1300 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1301 * returned in that order.
1302 *
1303 * @throws java.lang.reflect.GenericSignatureFormatError
1304 * if the generic class signature does not conform to the
1305 * format specified in section {@jvms 4.7.9} of <cite>The
1306 * Java Virtual Machine Specification</cite>
1307 * @throws TypeNotPresentException if any of the generic
1308 * superinterfaces refers to a non-existent type declaration
1309 * @throws java.lang.reflect.MalformedParameterizedTypeException
1310 * if any of the generic superinterfaces refer to a parameterized
1311 * type that cannot be instantiated for any reason
1312 * @return an array of interfaces directly implemented by this class
1313 * @since 1.5
1314 */
1315 public Type[] getGenericInterfaces() {
1316 ClassRepository info = getGenericInfo();
1317 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1318 }
1319
1320
1321 /**
1322 * Returns the {@code Class} representing the component type of an
1323 * array. If this class does not represent an array class this method
1324 * returns null.
1325 *
1326 * @return the {@code Class} representing the component type of this
1327 * class if this class is an array
1328 * @see java.lang.reflect.Array
1329 * @since 1.1
1330 */
1331 public Class<?> getComponentType() {
1332 return componentType;
1333 }
1334
1335 // The componentType field's null value is the sole indication that the class
1336 // is an array - see isArray().
1337 private transient final Class<?> componentType;
1338
1339 /*
1340 * Returns the {@code Class} representing the element type of an array class.
1341 * If this class does not represent an array class, then this method returns
1342 * {@code null}.
1343 */
1344 private Class<?> elementType() {
1345 if (!isArray()) return null;
1346
1347 Class<?> c = this;
1348 while (c.isArray()) {
1349 c = c.getComponentType();
1350 }
1351 return c;
1352 }
1353
1354 /**
1355 * Returns the Java language modifiers for this class or interface, encoded
1356 * in an integer. The modifiers consist of the Java Virtual Machine's
1357 * constants for {@code public}, {@code protected},
1358 * {@code private}, {@code final}, {@code static},
1359 * {@code abstract} and {@code interface}; they should be decoded
1360 * using the methods of class {@code Modifier}.
1361 *
1362 * <p> If the underlying class is an array class:
1363 * <ul>
1364 * <li> its {@code public}, {@code private} and {@code protected}
1365 * modifiers are the same as those of its component type
1366 * <li> its {@code abstract} and {@code final} modifiers are always
1367 * {@code true}
1368 * <li> its interface modifier is always {@code false}, even when
1369 * the component type is an interface
1370 * </ul>
1371 * If this {@code Class} object represents a primitive type or
1372 * void, its {@code public}, {@code abstract}, and {@code final}
1373 * modifiers are always {@code true}.
1374 * For {@code Class} objects representing void, primitive types, and
1375 * arrays, the values of other modifiers are {@code false} other
1376 * than as specified above.
1377 *
1378 * <p> The modifier encodings are defined in section {@jvms 4.1}
1379 * of <cite>The Java Virtual Machine Specification</cite>.
1380 *
1381 * @return the {@code int} representing the modifiers for this class
1382 * @see java.lang.reflect.Modifier
1383 * @see #accessFlags()
1384 * @see <a
1385 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1386 * programming language and JVM modeling in core reflection</a>
1387 * @since 1.1
1388 * @jls 8.1.1 Class Modifiers
1389 * @jls 9.1.1 Interface Modifiers
1390 * @jvms 4.1 The {@code ClassFile} Structure
1391 */
1392 public int getModifiers() { return modifiers; }
1393
1394 /**
1395 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1396 * flags} for this class, possibly empty}
1397 *
1398 * <p> If the underlying class is an array class:
1399 * <ul>
1400 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1401 * access flags are the same as those of its component type
1402 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1403 * <li> its {@code INTERFACE} flag is absent, even when the
1404 * component type is an interface
1405 * </ul>
1406 * If this {@code Class} object represents a primitive type or
1407 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1408 * {@code FINAL}.
1409 * For {@code Class} objects representing void, primitive types, and
1410 * arrays, access flags are absent other than as specified above.
1411 *
1412 * @see #getModifiers()
1413 * @jvms 4.1 The ClassFile Structure
1414 * @jvms 4.7.6 The InnerClasses Attribute
1415 * @since 20
1416 */
1417 public Set<AccessFlag> accessFlags() {
1418 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1419 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1420 // and STATIC, which are not allowed on Location.CLASS.
1421 // Use getClassFileAccessFlags to expose SUPER status.
1422 var location = (isMemberClass() || isLocalClass() ||
1423 isAnonymousClass() || isArray()) ?
1424 AccessFlag.Location.INNER_CLASS :
1425 AccessFlag.Location.CLASS;
1426 return getReflectionFactory().parseAccessFlags((location == AccessFlag.Location.CLASS) ?
1427 getClassFileAccessFlags() : getModifiers(), location, this);
1428 }
1429
1430 /**
1431 * Gets the signers of this class.
1432 *
1433 * @return the signers of this class, or null if there are no signers. In
1434 * particular, this method returns null if this {@code Class} object represents
1435 * a primitive type or void.
1436 * @since 1.1
1437 */
1438 public Object[] getSigners() {
1439 var signers = this.signers;
1440 return signers == null ? null : signers.clone();
1441 }
1442
1443 /**
1444 * Set the signers of this class.
1445 */
1446 void setSigners(Object[] signers) {
1447 if (!isPrimitive() && !isArray()) {
1448 this.signers = signers;
1449 }
1450 }
1451
1452 /**
1453 * If this {@code Class} object represents a local or anonymous
1454 * class within a method, returns a {@link
1455 * java.lang.reflect.Method Method} object representing the
1456 * immediately enclosing method of the underlying class. Returns
1457 * {@code null} otherwise.
1458 *
1459 * In particular, this method returns {@code null} if the underlying
1460 * class is a local or anonymous class immediately enclosed by a class or
1461 * interface declaration, instance initializer or static initializer.
1462 *
1463 * @return the immediately enclosing method of the underlying class, if
1464 * that class is a local or anonymous class; otherwise {@code null}.
1465 *
1466 * @since 1.5
1467 */
1468 public Method getEnclosingMethod() {
1469 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1470
1471 if (enclosingInfo == null)
1472 return null;
1473 else {
1474 if (!enclosingInfo.isMethod())
1475 return null;
1476
1477 List<Class<?>> types = BytecodeDescriptor.parseMethod(enclosingInfo.getDescriptor(), getClassLoader());
1478 Class<?> returnType = types.removeLast();
1479 Class<?>[] parameterClasses = types.toArray(EMPTY_CLASS_ARRAY);
1480
1481 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1482 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1483
1484 /*
1485 * Loop over all declared methods; match method name,
1486 * number of and type of parameters, *and* return
1487 * type. Matching return type is also necessary
1488 * because of covariant returns, etc.
1489 */
1490 ReflectionFactory fact = getReflectionFactory();
1491 for (Method m : candidates) {
1492 if (m.getName().equals(enclosingInfo.getName()) &&
1493 arrayContentsEq(parameterClasses,
1494 fact.getExecutableSharedParameterTypes(m))) {
1495 // finally, check return type
1496 if (m.getReturnType().equals(returnType)) {
1497 return fact.copyMethod(m);
1498 }
1499 }
1500 }
1501
1502 throw new InternalError("Enclosing method not found");
1503 }
1504 }
1505
1506 private native Object[] getEnclosingMethod0();
1507
1508 private EnclosingMethodInfo getEnclosingMethodInfo() {
1509 Object[] enclosingInfo = getEnclosingMethod0();
1510 if (enclosingInfo == null)
1511 return null;
1512 else {
1513 return new EnclosingMethodInfo(enclosingInfo);
1514 }
1515 }
1516
1517 private static final class EnclosingMethodInfo {
1518 private final Class<?> enclosingClass;
1519 private final String name;
1520 private final String descriptor;
1521
1522 static void validate(Object[] enclosingInfo) {
1523 if (enclosingInfo.length != 3)
1524 throw new InternalError("Malformed enclosing method information");
1525 try {
1526 // The array is expected to have three elements:
1527
1528 // the immediately enclosing class
1529 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1530 assert(enclosingClass != null);
1531
1532 // the immediately enclosing method or constructor's
1533 // name (can be null).
1534 String name = (String)enclosingInfo[1];
1535
1536 // the immediately enclosing method or constructor's
1537 // descriptor (null iff name is).
1538 String descriptor = (String)enclosingInfo[2];
1539 assert((name != null && descriptor != null) || name == descriptor);
1540 } catch (ClassCastException cce) {
1541 throw new InternalError("Invalid type in enclosing method information", cce);
1542 }
1543 }
1544
1545 EnclosingMethodInfo(Object[] enclosingInfo) {
1546 validate(enclosingInfo);
1547 this.enclosingClass = (Class<?>)enclosingInfo[0];
1548 this.name = (String)enclosingInfo[1];
1549 this.descriptor = (String)enclosingInfo[2];
1550 }
1551
1552 boolean isPartial() {
1553 return enclosingClass == null || name == null || descriptor == null;
1554 }
1555
1556 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1557
1558 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1559
1560 Class<?> getEnclosingClass() { return enclosingClass; }
1561
1562 String getName() { return name; }
1563
1564 String getDescriptor() {
1565 // hotspot validates this descriptor to be either a field or method
1566 // descriptor as the "type" in a NameAndType in verification.
1567 // So this can still be a field descriptor
1568 if (descriptor.isEmpty() || descriptor.charAt(0) != '(') {
1569 throw new GenericSignatureFormatError("Bad method signature: " + descriptor);
1570 }
1571 return descriptor;
1572 }
1573 }
1574
1575 private static Class<?> toClass(Type o) {
1576 if (o instanceof GenericArrayType gat)
1577 return toClass(gat.getGenericComponentType()).arrayType();
1578 return (Class<?>)o;
1579 }
1580
1581 /**
1582 * If this {@code Class} object represents a local or anonymous
1583 * class within a constructor, returns a {@link
1584 * java.lang.reflect.Constructor Constructor} object representing
1585 * the immediately enclosing constructor of the underlying
1586 * class. Returns {@code null} otherwise. In particular, this
1587 * method returns {@code null} if the underlying class is a local
1588 * or anonymous class immediately enclosed by a class or
1589 * interface declaration, instance initializer or static initializer.
1590 *
1591 * @return the immediately enclosing constructor of the underlying class, if
1592 * that class is a local or anonymous class; otherwise {@code null}.
1593 *
1594 * @since 1.5
1595 */
1596 public Constructor<?> getEnclosingConstructor() {
1597 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1598
1599 if (enclosingInfo == null)
1600 return null;
1601 else {
1602 if (!enclosingInfo.isConstructor())
1603 return null;
1604
1605 List<Class<?>> types = BytecodeDescriptor.parseMethod(enclosingInfo.getDescriptor(), getClassLoader());
1606 types.removeLast();
1607 Class<?>[] parameterClasses = types.toArray(EMPTY_CLASS_ARRAY);
1608
1609 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1610 Constructor<?>[] candidates = enclosingCandidate
1611 .privateGetDeclaredConstructors(false);
1612 /*
1613 * Loop over all declared constructors; match number
1614 * of and type of parameters.
1615 */
1616 ReflectionFactory fact = getReflectionFactory();
1617 for (Constructor<?> c : candidates) {
1618 if (arrayContentsEq(parameterClasses,
1619 fact.getExecutableSharedParameterTypes(c))) {
1620 return fact.copyConstructor(c);
1621 }
1622 }
1623
1624 throw new InternalError("Enclosing constructor not found");
1625 }
1626 }
1627
1628
1629 /**
1630 * If the class or interface represented by this {@code Class} object
1631 * is a member of another class, returns the {@code Class} object
1632 * representing the class in which it was declared. This method returns
1633 * null if this class or interface is not a member of any other class. If
1634 * this {@code Class} object represents an array class, a primitive
1635 * type, or void, then this method returns null.
1636 *
1637 * @return the declaring class for this class
1638 * @since 1.1
1639 */
1640 public Class<?> getDeclaringClass() {
1641 return getDeclaringClass0();
1642 }
1643
1644 private native Class<?> getDeclaringClass0();
1645
1646
1647 /**
1648 * Returns the immediately enclosing class of the underlying
1649 * class. If the underlying class is a top level class this
1650 * method returns {@code null}.
1651 * @return the immediately enclosing class of the underlying class
1652 * @since 1.5
1653 */
1654 public Class<?> getEnclosingClass() {
1655 // There are five kinds of classes (or interfaces):
1656 // a) Top level classes
1657 // b) Nested classes (static member classes)
1658 // c) Inner classes (non-static member classes)
1659 // d) Local classes (named classes declared within a method)
1660 // e) Anonymous classes
1661
1662
1663 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1664 // attribute if and only if it is a local class or an
1665 // anonymous class.
1666 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1667 Class<?> enclosingCandidate;
1668
1669 if (enclosingInfo == null) {
1670 // This is a top level or a nested class or an inner class (a, b, or c)
1671 enclosingCandidate = getDeclaringClass0();
1672 } else {
1673 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1674 // This is a local class or an anonymous class (d or e)
1675 if (enclosingClass == this || enclosingClass == null)
1676 throw new InternalError("Malformed enclosing method information");
1677 else
1678 enclosingCandidate = enclosingClass;
1679 }
1680 return enclosingCandidate;
1681 }
1682
1683 /**
1684 * Returns the simple name of the underlying class as given in the
1685 * source code. An empty string is returned if the underlying class is
1686 * {@linkplain #isAnonymousClass() anonymous}.
1687 * A {@linkplain #isSynthetic() synthetic class}, one not present
1688 * in source code, can have a non-empty name including special
1689 * characters, such as "{@code $}".
1690 *
1691 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1692 * component type with "[]" appended. In particular the simple
1693 * name of an array class whose component type is anonymous is "[]".
1694 *
1695 * @return the simple name of the underlying class
1696 * @since 1.5
1697 */
1698 public String getSimpleName() {
1699 ReflectionData<T> rd = reflectionData();
1700 String simpleName = rd.simpleName;
1701 if (simpleName == null) {
1702 rd.simpleName = simpleName = getSimpleName0();
1703 }
1704 return simpleName;
1705 }
1706
1707 private String getSimpleName0() {
1708 if (isArray()) {
1709 return getComponentType().getSimpleName().concat("[]");
1710 }
1711 String simpleName = getSimpleBinaryName();
1712 if (simpleName == null) { // top level class
1713 simpleName = getName();
1714 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1715 }
1716 return simpleName;
1717 }
1718
1719 /**
1720 * Return an informative string for the name of this class or interface.
1721 *
1722 * @return an informative string for the name of this class or interface
1723 * @since 1.8
1724 */
1725 public String getTypeName() {
1726 if (isArray()) {
1727 try {
1728 Class<?> cl = this;
1729 int dimensions = 0;
1730 do {
1731 dimensions++;
1732 cl = cl.getComponentType();
1733 } while (cl.isArray());
1734 return cl.getName().concat("[]".repeat(dimensions));
1735 } catch (Throwable e) { /*FALLTHRU*/ }
1736 }
1737 return getName();
1738 }
1739
1740 /**
1741 * Returns the canonical name of the underlying class as
1742 * defined by <cite>The Java Language Specification</cite>.
1743 * Returns {@code null} if the underlying class does not have a canonical
1744 * name. Classes without canonical names include:
1745 * <ul>
1746 * <li>a {@linkplain #isLocalClass() local class}
1747 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1748 * <li>a {@linkplain #isHidden() hidden class}
1749 * <li>an array whose component type does not have a canonical name</li>
1750 * </ul>
1751 *
1752 * The canonical name for a primitive class is the keyword for the
1753 * corresponding primitive type ({@code byte}, {@code short},
1754 * {@code char}, {@code int}, and so on).
1755 *
1756 * <p>An array type has a canonical name if and only if its
1757 * component type has a canonical name. When an array type has a
1758 * canonical name, it is equal to the canonical name of the
1759 * component type followed by "{@code []}".
1760 *
1761 * @return the canonical name of the underlying class if it exists, and
1762 * {@code null} otherwise.
1763 * @jls 6.7 Fully Qualified Names and Canonical Names
1764 * @since 1.5
1765 */
1766 public String getCanonicalName() {
1767 ReflectionData<T> rd = reflectionData();
1768 String canonicalName = rd.canonicalName;
1769 if (canonicalName == null) {
1770 rd.canonicalName = canonicalName = getCanonicalName0();
1771 }
1772 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1773 }
1774
1775 private String getCanonicalName0() {
1776 if (isArray()) {
1777 String canonicalName = getComponentType().getCanonicalName();
1778 if (canonicalName != null)
1779 return canonicalName.concat("[]");
1780 else
1781 return ReflectionData.NULL_SENTINEL;
1782 }
1783 if (isHidden() || isLocalOrAnonymousClass())
1784 return ReflectionData.NULL_SENTINEL;
1785 Class<?> enclosingClass = getEnclosingClass();
1786 if (enclosingClass == null) { // top level class
1787 return getName();
1788 } else {
1789 String enclosingName = enclosingClass.getCanonicalName();
1790 if (enclosingName == null)
1791 return ReflectionData.NULL_SENTINEL;
1792 String simpleName = getSimpleName();
1793 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1794 .append(enclosingName)
1795 .append('.')
1796 .append(simpleName)
1797 .toString();
1798 }
1799 }
1800
1801 /**
1802 * Returns {@code true} if and only if the underlying class
1803 * is an anonymous class.
1804 *
1805 * @apiNote
1806 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1807 *
1808 * @return {@code true} if and only if this class is an anonymous class.
1809 * @since 1.5
1810 * @jls 15.9.5 Anonymous Class Declarations
1811 */
1812 public boolean isAnonymousClass() {
1813 return !isArray() && isLocalOrAnonymousClass() &&
1814 getSimpleBinaryName0() == null;
1815 }
1816
1817 /**
1818 * Returns {@code true} if and only if the underlying class
1819 * is a local class.
1820 *
1821 * @return {@code true} if and only if this class is a local class.
1822 * @since 1.5
1823 * @jls 14.3 Local Class and Interface Declarations
1824 */
1825 public boolean isLocalClass() {
1826 return isLocalOrAnonymousClass() &&
1827 (isArray() || getSimpleBinaryName0() != null);
1828 }
1829
1830 /**
1831 * Returns {@code true} if and only if the underlying class
1832 * is a member class.
1833 *
1834 * @return {@code true} if and only if this class is a member class.
1835 * @since 1.5
1836 * @jls 8.5 Member Class and Interface Declarations
1837 */
1838 public boolean isMemberClass() {
1839 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1840 }
1841
1842 /**
1843 * Returns the "simple binary name" of the underlying class, i.e.,
1844 * the binary name without the leading enclosing class name.
1845 * Returns {@code null} if the underlying class is a top level
1846 * class.
1847 */
1848 private String getSimpleBinaryName() {
1849 if (isTopLevelClass())
1850 return null;
1851 String name = getSimpleBinaryName0();
1852 if (name == null) // anonymous class
1853 return "";
1854 return name;
1855 }
1856
1857 private native String getSimpleBinaryName0();
1858
1859 /**
1860 * Returns {@code true} if this is a top level class. Returns {@code false}
1861 * otherwise.
1862 */
1863 private boolean isTopLevelClass() {
1864 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1865 }
1866
1867 /**
1868 * Returns {@code true} if this is a local class or an anonymous
1869 * class. Returns {@code false} otherwise.
1870 */
1871 private boolean isLocalOrAnonymousClass() {
1872 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1873 // attribute if and only if it is a local class or an
1874 // anonymous class.
1875 return hasEnclosingMethodInfo();
1876 }
1877
1878 private boolean hasEnclosingMethodInfo() {
1879 Object[] enclosingInfo = getEnclosingMethod0();
1880 if (enclosingInfo != null) {
1881 EnclosingMethodInfo.validate(enclosingInfo);
1882 return true;
1883 }
1884 return false;
1885 }
1886
1887 /**
1888 * Returns an array containing {@code Class} objects representing all
1889 * the public classes and interfaces that are members of the class
1890 * represented by this {@code Class} object. This includes public
1891 * class and interface members inherited from superclasses and public class
1892 * and interface members declared by the class. This method returns an
1893 * array of length 0 if this {@code Class} object has no public member
1894 * classes or interfaces. This method also returns an array of length 0 if
1895 * this {@code Class} object represents a primitive type, an array
1896 * class, or void.
1897 *
1898 * @return the array of {@code Class} objects representing the public
1899 * members of this class
1900 * @since 1.1
1901 */
1902 public Class<?>[] getClasses() {
1903 List<Class<?>> list = new ArrayList<>();
1904 Class<?> currentClass = Class.this;
1905 while (currentClass != null) {
1906 for (Class<?> m : currentClass.getDeclaredClasses()) {
1907 if (Modifier.isPublic(m.getModifiers())) {
1908 list.add(m);
1909 }
1910 }
1911 currentClass = currentClass.getSuperclass();
1912 }
1913 return list.toArray(EMPTY_CLASS_ARRAY);
1914 }
1915
1916
1917 /**
1918 * Returns an array containing {@code Field} objects reflecting all
1919 * the accessible public fields of the class or interface represented by
1920 * this {@code Class} object.
1921 *
1922 * <p> If this {@code Class} object represents a class or interface with
1923 * no accessible public fields, then this method returns an array of length
1924 * 0.
1925 *
1926 * <p> If this {@code Class} object represents a class, then this method
1927 * returns the public fields of the class and of all its superclasses and
1928 * superinterfaces.
1929 *
1930 * <p> If this {@code Class} object represents an interface, then this
1931 * method returns the fields of the interface and of all its
1932 * superinterfaces.
1933 *
1934 * <p> If this {@code Class} object represents an array type, a primitive
1935 * type, or void, then this method returns an array of length 0.
1936 *
1937 * <p> The elements in the returned array are not sorted and are not in any
1938 * particular order.
1939 *
1940 * @return the array of {@code Field} objects representing the
1941 * public fields
1942 *
1943 * @since 1.1
1944 * @jls 8.2 Class Members
1945 * @jls 8.3 Field Declarations
1946 */
1947 public Field[] getFields() {
1948 return copyFields(privateGetPublicFields());
1949 }
1950
1951
1952 /**
1953 * Returns an array containing {@code Method} objects reflecting all the
1954 * public methods of the class or interface represented by this {@code
1955 * Class} object, including those declared by the class or interface and
1956 * those inherited from superclasses and superinterfaces.
1957 *
1958 * <p> If this {@code Class} object represents an array type, then the
1959 * returned array has a {@code Method} object for each of the public
1960 * methods inherited by the array type from {@code Object}. It does not
1961 * contain a {@code Method} object for {@code clone()}.
1962 *
1963 * <p> If this {@code Class} object represents an interface then the
1964 * returned array does not contain any implicitly declared methods from
1965 * {@code Object}. Therefore, if no methods are explicitly declared in
1966 * this interface or any of its superinterfaces then the returned array
1967 * has length 0. (Note that a {@code Class} object which represents a class
1968 * always has public methods, inherited from {@code Object}.)
1969 *
1970 * <p> The returned array never contains methods with names {@value
1971 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1972 *
1973 * <p> The elements in the returned array are not sorted and are not in any
1974 * particular order.
1975 *
1976 * <p> Generally, the result is computed as with the following 4 step algorithm.
1977 * Let C be the class or interface represented by this {@code Class} object:
1978 * <ol>
1979 * <li> A union of methods is composed of:
1980 * <ol type="a">
1981 * <li> C's declared public instance and static methods as returned by
1982 * {@link #getDeclaredMethods()} and filtered to include only public
1983 * methods.</li>
1984 * <li> If C is a class other than {@code Object}, then include the result
1985 * of invoking this algorithm recursively on the superclass of C.</li>
1986 * <li> Include the results of invoking this algorithm recursively on all
1987 * direct superinterfaces of C, but include only instance methods.</li>
1988 * </ol></li>
1989 * <li> Union from step 1 is partitioned into subsets of methods with same
1990 * signature (name, parameter types) and return type.</li>
1991 * <li> Within each such subset only the most specific methods are selected.
1992 * Let method M be a method from a set of methods with same signature
1993 * and return type. M is most specific if there is no such method
1994 * N != M from the same set, such that N is more specific than M.
1995 * N is more specific than M if:
1996 * <ol type="a">
1997 * <li> N is declared by a class and M is declared by an interface; or</li>
1998 * <li> N and M are both declared by classes or both by interfaces and
1999 * N's declaring type is the same as or a subtype of M's declaring type
2000 * (clearly, if M's and N's declaring types are the same type, then
2001 * M and N are the same method).</li>
2002 * </ol></li>
2003 * <li> The result of this algorithm is the union of all selected methods from
2004 * step 3.</li>
2005 * </ol>
2006 *
2007 * @apiNote There may be more than one method with a particular name
2008 * and parameter types in a class because while the Java language forbids a
2009 * class to declare multiple methods with the same signature but different
2010 * return types, the Java virtual machine does not. This
2011 * increased flexibility in the virtual machine can be used to
2012 * implement various language features. For example, covariant
2013 * returns can be implemented with {@linkplain
2014 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2015 * method and the overriding method would have the same
2016 * signature but different return types.
2017 *
2018 * @return the array of {@code Method} objects representing the
2019 * public methods of this class
2020 *
2021 * @jls 8.2 Class Members
2022 * @jls 8.4 Method Declarations
2023 * @since 1.1
2024 */
2025 public Method[] getMethods() {
2026 return copyMethods(privateGetPublicMethods());
2027 }
2028
2029
2030 /**
2031 * Returns an array containing {@code Constructor} objects reflecting
2032 * all the public constructors of the class represented by this
2033 * {@code Class} object. An array of length 0 is returned if the
2034 * class has no public constructors, or if the class is an array class, or
2035 * if the class reflects a primitive type or void.
2036 *
2037 * @apiNote
2038 * While this method returns an array of {@code
2039 * Constructor<T>} objects (that is an array of constructors from
2040 * this class), the return type of this method is {@code
2041 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2042 * might be expected. This less informative return type is
2043 * necessary since after being returned from this method, the
2044 * array could be modified to hold {@code Constructor} objects for
2045 * different classes, which would violate the type guarantees of
2046 * {@code Constructor<T>[]}.
2047 *
2048 * @return the array of {@code Constructor} objects representing the
2049 * public constructors of this class
2050 *
2051 * @see #getDeclaredConstructors()
2052 * @since 1.1
2053 */
2054 public Constructor<?>[] getConstructors() {
2055 return copyConstructors(privateGetDeclaredConstructors(true));
2056 }
2057
2058
2059 /**
2060 * Returns a {@code Field} object that reflects the specified public member
2061 * field of the class or interface represented by this {@code Class}
2062 * object. The {@code name} parameter is a {@code String} specifying the
2063 * simple name of the desired field.
2064 *
2065 * <p> The field to be reflected is determined by the algorithm that
2066 * follows. Let C be the class or interface represented by this {@code Class} object:
2067 *
2068 * <OL>
2069 * <LI> If C declares a public field with the name specified, that is the
2070 * field to be reflected.</LI>
2071 * <LI> If no field was found in step 1 above, this algorithm is applied
2072 * recursively to each direct superinterface of C. The direct
2073 * superinterfaces are searched in the order they were declared.</LI>
2074 * <LI> If no field was found in steps 1 and 2 above, and C has a
2075 * superclass S, then this algorithm is invoked recursively upon S.
2076 * If C has no superclass, then a {@code NoSuchFieldException}
2077 * is thrown.</LI>
2078 * </OL>
2079 *
2080 * <p> If this {@code Class} object represents an array type, then this
2081 * method does not find the {@code length} field of the array type.
2082 *
2083 * @param name the field name
2084 * @return the {@code Field} object of this class specified by
2085 * {@code name}
2086 * @throws NoSuchFieldException if a field with the specified name is
2087 * not found.
2088 *
2089 * @since 1.1
2090 * @jls 8.2 Class Members
2091 * @jls 8.3 Field Declarations
2092 */
2093 public Field getField(String name) throws NoSuchFieldException {
2094 Objects.requireNonNull(name);
2095 Field field = getField0(name);
2096 if (field == null) {
2097 throw new NoSuchFieldException(name);
2098 }
2099 return getReflectionFactory().copyField(field);
2100 }
2101
2102
2103 /**
2104 * Returns a {@code Method} object that reflects the specified public
2105 * member method of the class or interface represented by this
2106 * {@code Class} object. The {@code name} parameter is a
2107 * {@code String} specifying the simple name of the desired method. The
2108 * {@code parameterTypes} parameter is an array of {@code Class}
2109 * objects that identify the method's formal parameter types, in declared
2110 * order. If {@code parameterTypes} is {@code null}, it is
2111 * treated as if it were an empty array.
2112 *
2113 * <p> If this {@code Class} object represents an array type, then this
2114 * method finds any public method inherited by the array type from
2115 * {@code Object} except method {@code clone()}.
2116 *
2117 * <p> If this {@code Class} object represents an interface then this
2118 * method does not find any implicitly declared method from
2119 * {@code Object}. Therefore, if no methods are explicitly declared in
2120 * this interface or any of its superinterfaces, then this method does not
2121 * find any method.
2122 *
2123 * <p> This method does not find any method with name {@value
2124 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2125 *
2126 * <p> Generally, the method to be reflected is determined by the 4 step
2127 * algorithm that follows.
2128 * Let C be the class or interface represented by this {@code Class} object:
2129 * <ol>
2130 * <li> A union of methods is composed of:
2131 * <ol type="a">
2132 * <li> C's declared public instance and static methods as returned by
2133 * {@link #getDeclaredMethods()} and filtered to include only public
2134 * methods that match given {@code name} and {@code parameterTypes}</li>
2135 * <li> If C is a class other than {@code Object}, then include the result
2136 * of invoking this algorithm recursively on the superclass of C.</li>
2137 * <li> Include the results of invoking this algorithm recursively on all
2138 * direct superinterfaces of C, but include only instance methods.</li>
2139 * </ol></li>
2140 * <li> This union is partitioned into subsets of methods with same
2141 * return type (the selection of methods from step 1 also guarantees that
2142 * they have the same method name and parameter types).</li>
2143 * <li> Within each such subset only the most specific methods are selected.
2144 * Let method M be a method from a set of methods with same VM
2145 * signature (return type, name, parameter types).
2146 * M is most specific if there is no such method N != M from the same
2147 * set, such that N is more specific than M. N is more specific than M
2148 * if:
2149 * <ol type="a">
2150 * <li> N is declared by a class and M is declared by an interface; or</li>
2151 * <li> N and M are both declared by classes or both by interfaces and
2152 * N's declaring type is the same as or a subtype of M's declaring type
2153 * (clearly, if M's and N's declaring types are the same type, then
2154 * M and N are the same method).</li>
2155 * </ol></li>
2156 * <li> The result of this algorithm is chosen arbitrarily from the methods
2157 * with most specific return type among all selected methods from step 3.
2158 * Let R be a return type of a method M from the set of all selected methods
2159 * from step 3. M is a method with most specific return type if there is
2160 * no such method N != M from the same set, having return type S != R,
2161 * such that S is a subtype of R as determined by
2162 * R.class.{@link #isAssignableFrom}(S.class).
2163 * </ol>
2164 *
2165 * @apiNote There may be more than one method with matching name and
2166 * parameter types in a class because while the Java language forbids a
2167 * class to declare multiple methods with the same signature but different
2168 * return types, the Java virtual machine does not. This
2169 * increased flexibility in the virtual machine can be used to
2170 * implement various language features. For example, covariant
2171 * returns can be implemented with {@linkplain
2172 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2173 * method and the overriding method would have the same
2174 * signature but different return types. This method would return the
2175 * overriding method as it would have a more specific return type.
2176 *
2177 * @param name the name of the method
2178 * @param parameterTypes the list of parameters, may be {@code null}
2179 * @return the {@code Method} object that matches the specified
2180 * {@code name} and {@code parameterTypes}
2181 * @throws NoSuchMethodException if a matching method is not found,
2182 * if {@code parameterTypes} contains {@code null},
2183 * or if the name is {@value ConstantDescs#INIT_NAME} or
2184 * {@value ConstantDescs#CLASS_INIT_NAME}
2185 *
2186 * @jls 8.2 Class Members
2187 * @jls 8.4 Method Declarations
2188 * @since 1.1
2189 */
2190 public Method getMethod(String name, Class<?>... parameterTypes)
2191 throws NoSuchMethodException {
2192 Objects.requireNonNull(name);
2193 Method method = getMethod0(name, parameterTypes);
2194 if (method == null) {
2195 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2196 }
2197 return getReflectionFactory().copyMethod(method);
2198 }
2199
2200 /**
2201 * Returns a {@code Constructor} object that reflects the specified
2202 * public constructor of the class represented by this {@code Class}
2203 * object. The {@code parameterTypes} parameter is an array of
2204 * {@code Class} objects that identify the constructor's formal
2205 * parameter types, in declared order.
2206 *
2207 * If this {@code Class} object represents an inner class
2208 * declared in a non-static context, the formal parameter types
2209 * include the explicit enclosing instance as the first parameter.
2210 *
2211 * <p> The constructor to reflect is the public constructor of the class
2212 * represented by this {@code Class} object whose formal parameter
2213 * types match those specified by {@code parameterTypes}.
2214 *
2215 * @param parameterTypes the parameter array, may be {@code null}
2216 * @return the {@code Constructor} object of the public constructor that
2217 * matches the specified {@code parameterTypes}
2218 * @throws NoSuchMethodException if a matching constructor is not found,
2219 * if this {@code Class} object represents an interface, a primitive
2220 * type, an array class, or void, or if {@code parameterTypes}
2221 * contains {@code null}
2222 *
2223 * @see #getDeclaredConstructor(Class[])
2224 * @since 1.1
2225 */
2226 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2227 throws NoSuchMethodException {
2228 return getReflectionFactory().copyConstructor(
2229 getConstructor0(parameterTypes, Member.PUBLIC));
2230 }
2231
2232
2233 /**
2234 * Returns an array of {@code Class} objects reflecting all the
2235 * classes and interfaces declared as members of the class represented by
2236 * this {@code Class} object. This includes public, protected, default
2237 * (package) access, and private classes and interfaces declared by the
2238 * class, but excludes inherited classes and interfaces. This method
2239 * returns an array of length 0 if the class declares no classes or
2240 * interfaces as members, or if this {@code Class} object represents a
2241 * primitive type, an array class, or void.
2242 *
2243 * @return the array of {@code Class} objects representing all the
2244 * declared members of this class
2245 *
2246 * @since 1.1
2247 * @jls 8.5 Member Class and Interface Declarations
2248 */
2249 public Class<?>[] getDeclaredClasses() {
2250 return getDeclaredClasses0();
2251 }
2252
2253
2254 /**
2255 * Returns an array of {@code Field} objects reflecting all the fields
2256 * declared by the class or interface represented by this
2257 * {@code Class} object. This includes public, protected, default
2258 * (package) access, and private fields, but excludes inherited fields.
2259 *
2260 * <p> If this {@code Class} object represents a class or interface with no
2261 * declared fields, then this method returns an array of length 0.
2262 *
2263 * <p> If this {@code Class} object represents an array type, a primitive
2264 * type, or void, then this method returns an array of length 0.
2265 *
2266 * <p> The elements in the returned array are not sorted and are not in any
2267 * particular order.
2268 *
2269 * @return the array of {@code Field} objects representing all the
2270 * declared fields of this class
2271 *
2272 * @since 1.1
2273 * @jls 8.2 Class Members
2274 * @jls 8.3 Field Declarations
2275 */
2276 public Field[] getDeclaredFields() {
2277 return copyFields(privateGetDeclaredFields(false));
2278 }
2279
2280 /**
2281 * Returns an array of {@code RecordComponent} objects representing all the
2282 * record components of this record class, or {@code null} if this class is
2283 * not a record class.
2284 *
2285 * <p> The components are returned in the same order that they are declared
2286 * in the record header. The array is empty if this record class has no
2287 * components. If the class is not a record class, that is {@link
2288 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2289 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2290 * returns a non-null value.
2291 *
2292 * @apiNote
2293 * <p> The following method can be used to find the record canonical constructor:
2294 *
2295 * {@snippet lang="java" :
2296 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2297 * throws NoSuchMethodException {
2298 * Class<?>[] paramTypes =
2299 * Arrays.stream(cls.getRecordComponents())
2300 * .map(RecordComponent::getType)
2301 * .toArray(Class<?>[]::new);
2302 * return cls.getDeclaredConstructor(paramTypes);
2303 * }}
2304 *
2305 * @return An array of {@code RecordComponent} objects representing all the
2306 * record components of this record class, or {@code null} if this
2307 * class is not a record class
2308 *
2309 * @jls 8.10 Record Classes
2310 * @since 16
2311 */
2312 public RecordComponent[] getRecordComponents() {
2313 if (!isRecord()) {
2314 return null;
2315 }
2316 return getRecordComponents0();
2317 }
2318
2319 /**
2320 * Returns an array containing {@code Method} objects reflecting all the
2321 * declared methods of the class or interface represented by this {@code
2322 * Class} object, including public, protected, default (package)
2323 * access, and private methods, but excluding inherited methods.
2324 * The declared methods may include methods <em>not</em> in the
2325 * source of the class or interface, including {@linkplain
2326 * Method#isBridge bridge methods} and other {@linkplain
2327 * Executable#isSynthetic synthetic} methods added by compilers.
2328 *
2329 * <p> If this {@code Class} object represents a class or interface that
2330 * has multiple declared methods with the same name and parameter types,
2331 * but different return types, then the returned array has a {@code Method}
2332 * object for each such method.
2333 *
2334 * <p> If this {@code Class} object represents a class or interface that
2335 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2336 * then the returned array does <em>not</em> have a corresponding {@code
2337 * Method} object.
2338 *
2339 * <p> If this {@code Class} object represents a class or interface with no
2340 * declared methods, then the returned array has length 0.
2341 *
2342 * <p> If this {@code Class} object represents an array type, a primitive
2343 * type, or void, then the returned array has length 0.
2344 *
2345 * <p> The elements in the returned array are not sorted and are not in any
2346 * particular order.
2347 *
2348 * @return the array of {@code Method} objects representing all the
2349 * declared methods of this class
2350 *
2351 * @jls 8.2 Class Members
2352 * @jls 8.4 Method Declarations
2353 * @see <a
2354 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2355 * programming language and JVM modeling in core reflection</a>
2356 * @since 1.1
2357 */
2358 public Method[] getDeclaredMethods() {
2359 return copyMethods(privateGetDeclaredMethods(false));
2360 }
2361
2362 /**
2363 * Returns an array of {@code Constructor} objects reflecting all the
2364 * constructors implicitly or explicitly declared by the class represented by this
2365 * {@code Class} object. These are public, protected, default
2366 * (package) access, and private constructors. The elements in the array
2367 * returned are not sorted and are not in any particular order. If the
2368 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2369 * If a record class has a canonical constructor (JLS {@jls
2370 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2371 *
2372 * This method returns an array of length 0 if this {@code Class}
2373 * object represents an interface, a primitive type, an array class, or
2374 * void.
2375 *
2376 * @return the array of {@code Constructor} objects representing all the
2377 * declared constructors of this class
2378 *
2379 * @since 1.1
2380 * @see #getConstructors()
2381 * @jls 8.8 Constructor Declarations
2382 */
2383 public Constructor<?>[] getDeclaredConstructors() {
2384 return copyConstructors(privateGetDeclaredConstructors(false));
2385 }
2386
2387
2388 /**
2389 * Returns a {@code Field} object that reflects the specified declared
2390 * field of the class or interface represented by this {@code Class}
2391 * object. The {@code name} parameter is a {@code String} that specifies
2392 * the simple name of the desired field.
2393 *
2394 * <p> If this {@code Class} object represents an array type, then this
2395 * method does not find the {@code length} field of the array type.
2396 *
2397 * @param name the name of the field
2398 * @return the {@code Field} object for the specified field in this
2399 * class
2400 * @throws NoSuchFieldException if a field with the specified name is
2401 * not found.
2402 *
2403 * @since 1.1
2404 * @jls 8.2 Class Members
2405 * @jls 8.3 Field Declarations
2406 */
2407 public Field getDeclaredField(String name) throws NoSuchFieldException {
2408 Objects.requireNonNull(name);
2409 Field field = searchFields(privateGetDeclaredFields(false), name);
2410 if (field == null) {
2411 throw new NoSuchFieldException(name);
2412 }
2413 return getReflectionFactory().copyField(field);
2414 }
2415
2416
2417 /**
2418 * Returns a {@code Method} object that reflects the specified
2419 * declared method of the class or interface represented by this
2420 * {@code Class} object. The {@code name} parameter is a
2421 * {@code String} that specifies the simple name of the desired
2422 * method, and the {@code parameterTypes} parameter is an array of
2423 * {@code Class} objects that identify the method's formal parameter
2424 * types, in declared order. If more than one method with the same
2425 * parameter types is declared in a class, and one of these methods has a
2426 * return type that is more specific than any of the others, that method is
2427 * returned; otherwise one of the methods is chosen arbitrarily. If the
2428 * name is {@value ConstantDescs#INIT_NAME} or {@value
2429 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2430 * is raised.
2431 *
2432 * <p> If this {@code Class} object represents an array type, then this
2433 * method does not find the {@code clone()} method.
2434 *
2435 * @param name the name of the method
2436 * @param parameterTypes the parameter array, may be {@code null}
2437 * @return the {@code Method} object for the method of this class
2438 * matching the specified name and parameters
2439 * @throws NoSuchMethodException if a matching method is not found,
2440 * if {@code parameterTypes} contains {@code null},
2441 * or if the name is {@value ConstantDescs#INIT_NAME} or
2442 * {@value ConstantDescs#CLASS_INIT_NAME}
2443 *
2444 * @jls 8.2 Class Members
2445 * @jls 8.4 Method Declarations
2446 * @since 1.1
2447 */
2448 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2449 throws NoSuchMethodException {
2450 Objects.requireNonNull(name);
2451 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2452 if (method == null) {
2453 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2454 }
2455 return getReflectionFactory().copyMethod(method);
2456 }
2457
2458 /**
2459 * Returns the list of {@code Method} objects for the declared public
2460 * methods of this class or interface that have the specified method name
2461 * and parameter types.
2462 *
2463 * @param name the name of the method
2464 * @param parameterTypes the parameter array
2465 * @return the list of {@code Method} objects for the public methods of
2466 * this class matching the specified name and parameters
2467 */
2468 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2469 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2470 ReflectionFactory factory = getReflectionFactory();
2471 List<Method> result = new ArrayList<>();
2472 for (Method method : methods) {
2473 if (method.getName().equals(name)
2474 && Arrays.equals(
2475 factory.getExecutableSharedParameterTypes(method),
2476 parameterTypes)) {
2477 result.add(factory.copyMethod(method));
2478 }
2479 }
2480 return result;
2481 }
2482
2483 /**
2484 * Returns the most specific {@code Method} object of this class, super class or
2485 * interface that have the specified method name and parameter types.
2486 *
2487 * @param publicOnly true if only public methods are examined, otherwise all methods
2488 * @param name the name of the method
2489 * @param parameterTypes the parameter array
2490 * @return the {@code Method} object for the method found from this class matching
2491 * the specified name and parameters, or null if not found
2492 */
2493 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2494 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2495 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2496 }
2497
2498 /**
2499 * Returns a {@code Constructor} object that reflects the specified
2500 * constructor of the class represented by this
2501 * {@code Class} object. The {@code parameterTypes} parameter is
2502 * an array of {@code Class} objects that identify the constructor's
2503 * formal parameter types, in declared order.
2504 *
2505 * If this {@code Class} object represents an inner class
2506 * declared in a non-static context, the formal parameter types
2507 * include the explicit enclosing instance as the first parameter.
2508 *
2509 * @param parameterTypes the parameter array, may be {@code null}
2510 * @return The {@code Constructor} object for the constructor with the
2511 * specified parameter list
2512 * @throws NoSuchMethodException if a matching constructor is not found,
2513 * if this {@code Class} object represents an interface, a
2514 * primitive type, an array class, or void, or if
2515 * {@code parameterTypes} contains {@code null}
2516 *
2517 * @see #getConstructor(Class[])
2518 * @since 1.1
2519 */
2520 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2521 throws NoSuchMethodException {
2522 return getReflectionFactory().copyConstructor(
2523 getConstructor0(parameterTypes, Member.DECLARED));
2524 }
2525
2526 /**
2527 * Finds a resource with a given name.
2528 *
2529 * <p> If this class is in a named {@link Module Module} then this method
2530 * will attempt to find the resource in the module. This is done by
2531 * delegating to the module's class loader {@link
2532 * ClassLoader#findResource(String,String) findResource(String,String)}
2533 * method, invoking it with the module name and the absolute name of the
2534 * resource. Resources in named modules are subject to the rules for
2535 * encapsulation specified in the {@code Module} {@link
2536 * Module#getResourceAsStream getResourceAsStream} method and so this
2537 * method returns {@code null} when the resource is a
2538 * non-"{@code .class}" resource in a package that is not open to the
2539 * caller's module.
2540 *
2541 * <p> Otherwise, if this class is not in a named module then the rules for
2542 * searching resources associated with a given class are implemented by the
2543 * defining {@linkplain ClassLoader class loader} of the class. This method
2544 * delegates to this {@code Class} object's class loader.
2545 * If this {@code Class} object was loaded by the bootstrap class loader,
2546 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2547 *
2548 * <p> Before delegation, an absolute resource name is constructed from the
2549 * given resource name using this algorithm:
2550 *
2551 * <ul>
2552 *
2553 * <li> If the {@code name} begins with a {@code '/'}
2554 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2555 * portion of the {@code name} following the {@code '/'}.
2556 *
2557 * <li> Otherwise, the absolute name is of the following form:
2558 *
2559 * <blockquote>
2560 * {@code modified_package_name/name}
2561 * </blockquote>
2562 *
2563 * <p> Where the {@code modified_package_name} is the package name of this
2564 * object with {@code '/'} substituted for {@code '.'}
2565 * (<code>'\u002e'</code>).
2566 *
2567 * </ul>
2568 *
2569 * @param name name of the desired resource
2570 * @return A {@link java.io.InputStream} object; {@code null} if no
2571 * resource with this name is found, or the resource is in a package
2572 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2573 * least the caller module.
2574 *
2575 * @see Module#getResourceAsStream(String)
2576 * @since 1.1
2577 */
2578 @CallerSensitive
2579 public InputStream getResourceAsStream(String name) {
2580 name = resolveName(name);
2581
2582 Module thisModule = getModule();
2583 if (thisModule.isNamed()) {
2584 // check if resource can be located by caller
2585 if (Resources.canEncapsulate(name)
2586 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2587 return null;
2588 }
2589
2590 // resource not encapsulated or in package open to caller
2591 String mn = thisModule.getName();
2592 ClassLoader cl = classLoader;
2593 try {
2594
2595 // special-case built-in class loaders to avoid the
2596 // need for a URL connection
2597 if (cl == null) {
2598 return BootLoader.findResourceAsStream(mn, name);
2599 } else if (cl instanceof BuiltinClassLoader bcl) {
2600 return bcl.findResourceAsStream(mn, name);
2601 } else {
2602 URL url = cl.findResource(mn, name);
2603 return (url != null) ? url.openStream() : null;
2604 }
2605
2606 } catch (IOException | SecurityException e) {
2607 return null;
2608 }
2609 }
2610
2611 // unnamed module
2612 ClassLoader cl = classLoader;
2613 if (cl == null) {
2614 return ClassLoader.getSystemResourceAsStream(name);
2615 } else {
2616 return cl.getResourceAsStream(name);
2617 }
2618 }
2619
2620 /**
2621 * Finds a resource with a given name.
2622 *
2623 * <p> If this class is in a named {@link Module Module} then this method
2624 * will attempt to find the resource in the module. This is done by
2625 * delegating to the module's class loader {@link
2626 * ClassLoader#findResource(String,String) findResource(String,String)}
2627 * method, invoking it with the module name and the absolute name of the
2628 * resource. Resources in named modules are subject to the rules for
2629 * encapsulation specified in the {@code Module} {@link
2630 * Module#getResourceAsStream getResourceAsStream} method and so this
2631 * method returns {@code null} when the resource is a
2632 * non-"{@code .class}" resource in a package that is not open to the
2633 * caller's module.
2634 *
2635 * <p> Otherwise, if this class is not in a named module then the rules for
2636 * searching resources associated with a given class are implemented by the
2637 * defining {@linkplain ClassLoader class loader} of the class. This method
2638 * delegates to this {@code Class} object's class loader.
2639 * If this {@code Class} object was loaded by the bootstrap class loader,
2640 * the method delegates to {@link ClassLoader#getSystemResource}.
2641 *
2642 * <p> Before delegation, an absolute resource name is constructed from the
2643 * given resource name using this algorithm:
2644 *
2645 * <ul>
2646 *
2647 * <li> If the {@code name} begins with a {@code '/'}
2648 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2649 * portion of the {@code name} following the {@code '/'}.
2650 *
2651 * <li> Otherwise, the absolute name is of the following form:
2652 *
2653 * <blockquote>
2654 * {@code modified_package_name/name}
2655 * </blockquote>
2656 *
2657 * <p> Where the {@code modified_package_name} is the package name of this
2658 * object with {@code '/'} substituted for {@code '.'}
2659 * (<code>'\u002e'</code>).
2660 *
2661 * </ul>
2662 *
2663 * @param name name of the desired resource
2664 * @return A {@link java.net.URL} object; {@code null} if no resource with
2665 * this name is found, the resource cannot be located by a URL, or the
2666 * resource is in a package that is not
2667 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2668 * module.
2669 * @since 1.1
2670 */
2671 @CallerSensitive
2672 public URL getResource(String name) {
2673 name = resolveName(name);
2674
2675 Module thisModule = getModule();
2676 if (thisModule.isNamed()) {
2677 // check if resource can be located by caller
2678 if (Resources.canEncapsulate(name)
2679 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2680 return null;
2681 }
2682
2683 // resource not encapsulated or in package open to caller
2684 String mn = thisModule.getName();
2685 ClassLoader cl = classLoader;
2686 try {
2687 if (cl == null) {
2688 return BootLoader.findResource(mn, name);
2689 } else {
2690 return cl.findResource(mn, name);
2691 }
2692 } catch (IOException ioe) {
2693 return null;
2694 }
2695 }
2696
2697 // unnamed module
2698 ClassLoader cl = classLoader;
2699 if (cl == null) {
2700 return ClassLoader.getSystemResource(name);
2701 } else {
2702 return cl.getResource(name);
2703 }
2704 }
2705
2706 /**
2707 * Returns true if a resource with the given name can be located by the
2708 * given caller. All resources in a module can be located by code in
2709 * the module. For other callers, then the package needs to be open to
2710 * the caller.
2711 */
2712 private boolean isOpenToCaller(String name, Class<?> caller) {
2713 // assert getModule().isNamed();
2714 Module thisModule = getModule();
2715 Module callerModule = (caller != null) ? caller.getModule() : null;
2716 if (callerModule != thisModule) {
2717 String pn = Resources.toPackageName(name);
2718 if (thisModule.getDescriptor().packages().contains(pn)) {
2719 if (callerModule == null) {
2720 // no caller, return true if the package is open to all modules
2721 return thisModule.isOpen(pn);
2722 }
2723 if (!thisModule.isOpen(pn, callerModule)) {
2724 // package not open to caller
2725 return false;
2726 }
2727 }
2728 }
2729 return true;
2730 }
2731
2732 private transient final ProtectionDomain protectionDomain;
2733
2734 /** Holder for the protection domain returned when the internal domain is null */
2735 private static class Holder {
2736 private static final ProtectionDomain allPermDomain;
2737 static {
2738 Permissions perms = new Permissions();
2739 perms.add(new AllPermission());
2740 allPermDomain = new ProtectionDomain(null, perms);
2741 }
2742 }
2743
2744 /**
2745 * Returns the {@code ProtectionDomain} of this class.
2746 *
2747 * @return the ProtectionDomain of this class
2748 *
2749 * @see java.security.ProtectionDomain
2750 * @since 1.2
2751 */
2752 public ProtectionDomain getProtectionDomain() {
2753 if (protectionDomain == null) {
2754 return Holder.allPermDomain;
2755 } else {
2756 return protectionDomain;
2757 }
2758 }
2759
2760 /*
2761 * Returns the Class object for the named primitive type. Type parameter T
2762 * avoids redundant casts for trusted code.
2763 */
2764 static native <T> Class<T> getPrimitiveClass(String name);
2765
2766 /**
2767 * Add a package name prefix if the name is not absolute. Remove leading "/"
2768 * if name is absolute
2769 */
2770 private String resolveName(String name) {
2771 if (!name.startsWith("/")) {
2772 String baseName = getPackageName();
2773 if (!baseName.isEmpty()) {
2774 int len = baseName.length() + 1 + name.length();
2775 StringBuilder sb = new StringBuilder(len);
2776 name = sb.append(baseName.replace('.', '/'))
2777 .append('/')
2778 .append(name)
2779 .toString();
2780 }
2781 } else {
2782 name = name.substring(1);
2783 }
2784 return name;
2785 }
2786
2787 /**
2788 * Atomic operations support.
2789 */
2790 private static class Atomic {
2791 // initialize Unsafe machinery here, since we need to call Class.class instance method
2792 // and have to avoid calling it in the static initializer of the Class class...
2793 private static final Unsafe unsafe = Unsafe.getUnsafe();
2794 // offset of Class.reflectionData instance field
2795 private static final long reflectionDataOffset
2796 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2797 // offset of Class.annotationType instance field
2798 private static final long annotationTypeOffset
2799 = unsafe.objectFieldOffset(Class.class, "annotationType");
2800 // offset of Class.annotationData instance field
2801 private static final long annotationDataOffset
2802 = unsafe.objectFieldOffset(Class.class, "annotationData");
2803
2804 static <T> boolean casReflectionData(Class<?> clazz,
2805 ReflectionData<T> oldData,
2806 ReflectionData<T> newData) {
2807 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2808 }
2809
2810 static boolean casAnnotationType(Class<?> clazz,
2811 AnnotationType oldType,
2812 AnnotationType newType) {
2813 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2814 }
2815
2816 static boolean casAnnotationData(Class<?> clazz,
2817 AnnotationData oldData,
2818 AnnotationData newData) {
2819 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2820 }
2821 }
2822
2823 /**
2824 * Reflection support.
2825 */
2826
2827 // Reflection data caches various derived names and reflective members. Cached
2828 // values may be invalidated when JVM TI RedefineClasses() is called
2829 private static class ReflectionData<T> {
2830 volatile Field[] declaredFields;
2831 volatile Field[] publicFields;
2832 volatile Method[] declaredMethods;
2833 volatile Method[] publicMethods;
2834 volatile Constructor<T>[] declaredConstructors;
2835 volatile Constructor<T>[] publicConstructors;
2836 // Intermediate results for getFields and getMethods
2837 volatile Field[] declaredPublicFields;
2838 volatile Method[] declaredPublicMethods;
2839 volatile Class<?>[] interfaces;
2840
2841 // Cached names
2842 String simpleName;
2843 String canonicalName;
2844 static final String NULL_SENTINEL = new String();
2845
2846 // Value of classRedefinedCount when we created this ReflectionData instance
2847 final int redefinedCount;
2848
2849 ReflectionData(int redefinedCount) {
2850 this.redefinedCount = redefinedCount;
2851 }
2852 }
2853
2854 private transient volatile ReflectionData<T> reflectionData;
2855
2856 // Incremented by the VM on each call to JVM TI RedefineClasses()
2857 // that redefines this class or a superclass.
2858 private transient volatile int classRedefinedCount;
2859
2860 // Lazily create and cache ReflectionData
2861 private ReflectionData<T> reflectionData() {
2862 ReflectionData<T> reflectionData = this.reflectionData;
2863 int classRedefinedCount = this.classRedefinedCount;
2864 if (reflectionData != null &&
2865 reflectionData.redefinedCount == classRedefinedCount) {
2866 return reflectionData;
2867 }
2868 // else no SoftReference or cleared SoftReference or stale ReflectionData
2869 // -> create and replace new instance
2870 return newReflectionData(reflectionData, classRedefinedCount);
2871 }
2872
2873 private ReflectionData<T> newReflectionData(ReflectionData<T> oldReflectionData,
2874 int classRedefinedCount) {
2875 while (true) {
2876 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2877 // try to CAS it...
2878 if (Atomic.casReflectionData(this, oldReflectionData, rd)) {
2879 return rd;
2880 }
2881 // else retry
2882 oldReflectionData = this.reflectionData;
2883 classRedefinedCount = this.classRedefinedCount;
2884 if (oldReflectionData != null && oldReflectionData.redefinedCount == classRedefinedCount) {
2885 return rd;
2886 }
2887 }
2888 }
2889
2890 // Generic signature handling
2891 private native String getGenericSignature0();
2892
2893 // Generic info repository; lazily initialized
2894 private transient volatile ClassRepository genericInfo;
2895
2896 // accessor for factory
2897 private GenericsFactory getFactory() {
2898 // create scope and factory
2899 return CoreReflectionFactory.make(this, ClassScope.make(this));
2900 }
2901
2902 // accessor for generic info repository;
2903 // generic info is lazily initialized
2904 private ClassRepository getGenericInfo() {
2905 ClassRepository genericInfo = this.genericInfo;
2906 if (genericInfo == null) {
2907 String signature = getGenericSignature0();
2908 if (signature == null) {
2909 genericInfo = ClassRepository.NONE;
2910 } else {
2911 genericInfo = ClassRepository.make(signature, getFactory());
2912 }
2913 this.genericInfo = genericInfo;
2914 }
2915 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2916 }
2917
2918 // Annotations handling
2919 native byte[] getRawAnnotations();
2920 // Since 1.8
2921 native byte[] getRawTypeAnnotations();
2922 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2923 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2924 }
2925
2926 native ConstantPool getConstantPool();
2927
2928 //
2929 //
2930 // java.lang.reflect.Field handling
2931 //
2932 //
2933
2934 // Returns an array of "root" fields. These Field objects must NOT
2935 // be propagated to the outside world, but must instead be copied
2936 // via ReflectionFactory.copyField.
2937 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2938 Field[] res;
2939 ReflectionData<T> rd = reflectionData();
2940 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2941 if (res != null) return res;
2942 // No cached value available; request value from VM
2943 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2944 if (publicOnly) {
2945 rd.declaredPublicFields = res;
2946 } else {
2947 rd.declaredFields = res;
2948 }
2949 return res;
2950 }
2951
2952 // Returns an array of "root" fields. These Field objects must NOT
2953 // be propagated to the outside world, but must instead be copied
2954 // via ReflectionFactory.copyField.
2955 private Field[] privateGetPublicFields() {
2956 Field[] res;
2957 ReflectionData<T> rd = reflectionData();
2958 res = rd.publicFields;
2959 if (res != null) return res;
2960
2961 // Use a linked hash set to ensure order is preserved and
2962 // fields from common super interfaces are not duplicated
2963 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2964
2965 // Local fields
2966 addAll(fields, privateGetDeclaredFields(true));
2967
2968 // Direct superinterfaces, recursively
2969 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2970 addAll(fields, si.privateGetPublicFields());
2971 }
2972
2973 // Direct superclass, recursively
2974 Class<?> sc = getSuperclass();
2975 if (sc != null) {
2976 addAll(fields, sc.privateGetPublicFields());
2977 }
2978
2979 res = fields.toArray(new Field[0]);
2980 rd.publicFields = res;
2981 return res;
2982 }
2983
2984 private static void addAll(Collection<Field> c, Field[] o) {
2985 for (Field f : o) {
2986 c.add(f);
2987 }
2988 }
2989
2990
2991 //
2992 //
2993 // java.lang.reflect.Constructor handling
2994 //
2995 //
2996
2997 // Returns an array of "root" constructors. These Constructor
2998 // objects must NOT be propagated to the outside world, but must
2999 // instead be copied via ReflectionFactory.copyConstructor.
3000 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3001 Constructor<T>[] res;
3002 ReflectionData<T> rd = reflectionData();
3003 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3004 if (res != null) return res;
3005 // No cached value available; request value from VM
3006 if (isInterface()) {
3007 @SuppressWarnings("unchecked")
3008 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3009 res = temporaryRes;
3010 } else {
3011 res = getDeclaredConstructors0(publicOnly);
3012 }
3013 if (publicOnly) {
3014 rd.publicConstructors = res;
3015 } else {
3016 rd.declaredConstructors = res;
3017 }
3018 return res;
3019 }
3020
3021 //
3022 //
3023 // java.lang.reflect.Method handling
3024 //
3025 //
3026
3027 // Returns an array of "root" methods. These Method objects must NOT
3028 // be propagated to the outside world, but must instead be copied
3029 // via ReflectionFactory.copyMethod.
3030 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3031 Method[] res;
3032 ReflectionData<T> rd = reflectionData();
3033 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3034 if (res != null) return res;
3035 // No cached value available; request value from VM
3036 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3037 if (publicOnly) {
3038 rd.declaredPublicMethods = res;
3039 } else {
3040 rd.declaredMethods = res;
3041 }
3042 return res;
3043 }
3044
3045 // Returns an array of "root" methods. These Method objects must NOT
3046 // be propagated to the outside world, but must instead be copied
3047 // via ReflectionFactory.copyMethod.
3048 private Method[] privateGetPublicMethods() {
3049 Method[] res;
3050 ReflectionData<T> rd = reflectionData();
3051 res = rd.publicMethods;
3052 if (res != null) return res;
3053
3054 // No cached value available; compute value recursively.
3055 // Start by fetching public declared methods...
3056 PublicMethods pms = new PublicMethods();
3057 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3058 pms.merge(m);
3059 }
3060 // ...then recur over superclass methods...
3061 Class<?> sc = getSuperclass();
3062 if (sc != null) {
3063 for (Method m : sc.privateGetPublicMethods()) {
3064 pms.merge(m);
3065 }
3066 }
3067 // ...and finally over direct superinterfaces.
3068 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3069 for (Method m : intf.privateGetPublicMethods()) {
3070 // static interface methods are not inherited
3071 if (!Modifier.isStatic(m.getModifiers())) {
3072 pms.merge(m);
3073 }
3074 }
3075 }
3076
3077 res = pms.toArray();
3078 rd.publicMethods = res;
3079 return res;
3080 }
3081
3082
3083 //
3084 // Helpers for fetchers of one field, method, or constructor
3085 //
3086
3087 // This method does not copy the returned Field object!
3088 private static Field searchFields(Field[] fields, String name) {
3089 for (Field field : fields) {
3090 if (field.getName().equals(name)) {
3091 return field;
3092 }
3093 }
3094 return null;
3095 }
3096
3097 // Returns a "root" Field object. This Field object must NOT
3098 // be propagated to the outside world, but must instead be copied
3099 // via ReflectionFactory.copyField.
3100 private Field getField0(String name) {
3101 // Note: the intent is that the search algorithm this routine
3102 // uses be equivalent to the ordering imposed by
3103 // privateGetPublicFields(). It fetches only the declared
3104 // public fields for each class, however, to reduce the number
3105 // of Field objects which have to be created for the common
3106 // case where the field being requested is declared in the
3107 // class which is being queried.
3108 Field res;
3109 // Search declared public fields
3110 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3111 return res;
3112 }
3113 // Direct superinterfaces, recursively
3114 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3115 for (Class<?> c : interfaces) {
3116 if ((res = c.getField0(name)) != null) {
3117 return res;
3118 }
3119 }
3120 // Direct superclass, recursively
3121 if (!isInterface()) {
3122 Class<?> c = getSuperclass();
3123 if (c != null) {
3124 if ((res = c.getField0(name)) != null) {
3125 return res;
3126 }
3127 }
3128 }
3129 return null;
3130 }
3131
3132 // This method does not copy the returned Method object!
3133 private static Method searchMethods(Method[] methods,
3134 String name,
3135 Class<?>[] parameterTypes)
3136 {
3137 ReflectionFactory fact = getReflectionFactory();
3138 Method res = null;
3139 for (Method m : methods) {
3140 if (m.getName().equals(name)
3141 && arrayContentsEq(parameterTypes,
3142 fact.getExecutableSharedParameterTypes(m))
3143 && (res == null
3144 || (res.getReturnType() != m.getReturnType()
3145 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3146 res = m;
3147 }
3148 return res;
3149 }
3150
3151 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3152
3153 // Returns a "root" Method object. This Method object must NOT
3154 // be propagated to the outside world, but must instead be copied
3155 // via ReflectionFactory.copyMethod.
3156 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3157 PublicMethods.MethodList res = getMethodsRecursive(
3158 name,
3159 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3160 /* includeStatic */ true, /* publicOnly */ true);
3161 return res == null ? null : res.getMostSpecific();
3162 }
3163
3164 // Returns a list of "root" Method objects. These Method objects must NOT
3165 // be propagated to the outside world, but must instead be copied
3166 // via ReflectionFactory.copyMethod.
3167 private PublicMethods.MethodList getMethodsRecursive(String name,
3168 Class<?>[] parameterTypes,
3169 boolean includeStatic,
3170 boolean publicOnly) {
3171 // 1st check declared methods
3172 Method[] methods = privateGetDeclaredMethods(publicOnly);
3173 PublicMethods.MethodList res = PublicMethods.MethodList
3174 .filter(methods, name, parameterTypes, includeStatic);
3175 // if there is at least one match among declared methods, we need not
3176 // search any further as such match surely overrides matching methods
3177 // declared in superclass(es) or interface(s).
3178 if (res != null) {
3179 return res;
3180 }
3181
3182 // if there was no match among declared methods,
3183 // we must consult the superclass (if any) recursively...
3184 Class<?> sc = getSuperclass();
3185 if (sc != null) {
3186 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3187 }
3188
3189 // ...and coalesce the superclass methods with methods obtained
3190 // from directly implemented interfaces excluding static methods...
3191 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3192 res = PublicMethods.MethodList.merge(
3193 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3194 }
3195
3196 return res;
3197 }
3198
3199 // Returns a "root" Constructor object. This Constructor object must NOT
3200 // be propagated to the outside world, but must instead be copied
3201 // via ReflectionFactory.copyConstructor.
3202 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3203 int which) throws NoSuchMethodException
3204 {
3205 ReflectionFactory fact = getReflectionFactory();
3206 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3207 for (Constructor<T> constructor : constructors) {
3208 if (arrayContentsEq(parameterTypes,
3209 fact.getExecutableSharedParameterTypes(constructor))) {
3210 return constructor;
3211 }
3212 }
3213 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3214 }
3215
3216 //
3217 // Other helpers and base implementation
3218 //
3219
3220 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3221 if (a1 == null) {
3222 return a2 == null || a2.length == 0;
3223 }
3224
3225 if (a2 == null) {
3226 return a1.length == 0;
3227 }
3228
3229 if (a1.length != a2.length) {
3230 return false;
3231 }
3232
3233 for (int i = 0; i < a1.length; i++) {
3234 if (a1[i] != a2[i]) {
3235 return false;
3236 }
3237 }
3238
3239 return true;
3240 }
3241
3242 private static Field[] copyFields(Field[] arg) {
3243 Field[] out = new Field[arg.length];
3244 ReflectionFactory fact = getReflectionFactory();
3245 for (int i = 0; i < arg.length; i++) {
3246 out[i] = fact.copyField(arg[i]);
3247 }
3248 return out;
3249 }
3250
3251 private static Method[] copyMethods(Method[] arg) {
3252 Method[] out = new Method[arg.length];
3253 ReflectionFactory fact = getReflectionFactory();
3254 for (int i = 0; i < arg.length; i++) {
3255 out[i] = fact.copyMethod(arg[i]);
3256 }
3257 return out;
3258 }
3259
3260 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3261 Constructor<U>[] out = arg.clone();
3262 ReflectionFactory fact = getReflectionFactory();
3263 for (int i = 0; i < out.length; i++) {
3264 out[i] = fact.copyConstructor(out[i]);
3265 }
3266 return out;
3267 }
3268
3269 private native Field[] getDeclaredFields0(boolean publicOnly);
3270 private native Method[] getDeclaredMethods0(boolean publicOnly);
3271 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3272 private native Class<?>[] getDeclaredClasses0();
3273
3274 /*
3275 * Returns an array containing the components of the Record attribute,
3276 * or null if the attribute is not present.
3277 *
3278 * Note that this method returns non-null array on a class with
3279 * the Record attribute even if this class is not a record.
3280 */
3281 private native RecordComponent[] getRecordComponents0();
3282 private native boolean isRecord0();
3283
3284 /**
3285 * Helper method to get the method name from arguments.
3286 */
3287 private String methodToString(String name, Class<?>[] argTypes) {
3288 return getName() + '.' + name +
3289 ((argTypes == null || argTypes.length == 0) ?
3290 "()" :
3291 Arrays.stream(argTypes)
3292 .map(c -> c == null ? "null" : c.getName())
3293 .collect(Collectors.joining(",", "(", ")")));
3294 }
3295
3296 /** use serialVersionUID from JDK 1.1 for interoperability */
3297 @java.io.Serial
3298 private static final long serialVersionUID = 3206093459760846163L;
3299
3300
3301 /**
3302 * Class Class is special cased within the Serialization Stream Protocol.
3303 *
3304 * A Class instance is written initially into an ObjectOutputStream in the
3305 * following format:
3306 * <pre>
3307 * {@code TC_CLASS} ClassDescriptor
3308 * A ClassDescriptor is a special cased serialization of
3309 * a {@code java.io.ObjectStreamClass} instance.
3310 * </pre>
3311 * A new handle is generated for the initial time the class descriptor
3312 * is written into the stream. Future references to the class descriptor
3313 * are written as references to the initial class descriptor instance.
3314 *
3315 * @see java.io.ObjectStreamClass
3316 */
3317 @java.io.Serial
3318 private static final ObjectStreamField[] serialPersistentFields =
3319 new ObjectStreamField[0];
3320
3321
3322 /**
3323 * Returns the assertion status that would be assigned to this
3324 * class if it were to be initialized at the time this method is invoked.
3325 * If this class has had its assertion status set, the most recent
3326 * setting will be returned; otherwise, if any package default assertion
3327 * status pertains to this class, the most recent setting for the most
3328 * specific pertinent package default assertion status is returned;
3329 * otherwise, if this class is not a system class (i.e., it has a
3330 * class loader) its class loader's default assertion status is returned;
3331 * otherwise, the system class default assertion status is returned.
3332 *
3333 * @apiNote
3334 * Few programmers will have any need for this method; it is provided
3335 * for the benefit of the JDK itself. (It allows a class to determine at
3336 * the time that it is initialized whether assertions should be enabled.)
3337 * Note that this method is not guaranteed to return the actual
3338 * assertion status that was (or will be) associated with the specified
3339 * class when it was (or will be) initialized.
3340 *
3341 * @return the desired assertion status of the specified class.
3342 * @see java.lang.ClassLoader#setClassAssertionStatus
3343 * @see java.lang.ClassLoader#setPackageAssertionStatus
3344 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3345 * @since 1.4
3346 */
3347 public boolean desiredAssertionStatus() {
3348 ClassLoader loader = classLoader;
3349 // If the loader is null this is a system class, so ask the VM
3350 if (loader == null)
3351 return desiredAssertionStatus0(this);
3352
3353 // If the classloader has been initialized with the assertion
3354 // directives, ask it. Otherwise, ask the VM.
3355 synchronized(loader.assertionLock) {
3356 if (loader.classAssertionStatus != null) {
3357 return loader.desiredAssertionStatus(getName());
3358 }
3359 }
3360 return desiredAssertionStatus0(this);
3361 }
3362
3363 // Retrieves the desired assertion status of this class from the VM
3364 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3365
3366 /**
3367 * Returns true if and only if this class was declared as an enum in the
3368 * source code.
3369 *
3370 * Note that {@link java.lang.Enum} is not itself an enum class.
3371 *
3372 * Also note that if an enum constant is declared with a class body,
3373 * the class of that enum constant object is an anonymous class
3374 * and <em>not</em> the class of the declaring enum class. The
3375 * {@link Enum#getDeclaringClass} method of an enum constant can
3376 * be used to get the class of the enum class declaring the
3377 * constant.
3378 *
3379 * @return true if and only if this class was declared as an enum in the
3380 * source code
3381 * @since 1.5
3382 * @jls 8.9.1 Enum Constants
3383 */
3384 public boolean isEnum() {
3385 // An enum must both directly extend java.lang.Enum and have
3386 // the ENUM bit set; classes for specialized enum constants
3387 // don't do the former.
3388 return (this.getModifiers() & ENUM) != 0 &&
3389 this.getSuperclass() == java.lang.Enum.class;
3390 }
3391
3392 /**
3393 * Returns {@code true} if and only if this class is a record class.
3394 *
3395 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3396 * class is {@code java.lang.Record}. A record class is {@linkplain
3397 * Modifier#FINAL final}. A record class has (possibly zero) record
3398 * components; {@link #getRecordComponents()} returns a non-null but
3399 * possibly empty value for a record.
3400 *
3401 * <p> Note that class {@link Record} is not a record class and thus
3402 * invoking this method on class {@code Record} returns {@code false}.
3403 *
3404 * @return true if and only if this class is a record class, otherwise false
3405 * @jls 8.10 Record Classes
3406 * @since 16
3407 */
3408 public boolean isRecord() {
3409 // this superclass and final modifier check is not strictly necessary
3410 // they are intrinsified and serve as a fast-path check
3411 return getSuperclass() == java.lang.Record.class &&
3412 (this.getModifiers() & Modifier.FINAL) != 0 &&
3413 isRecord0();
3414 }
3415
3416 // Fetches the factory for reflective objects
3417 private static ReflectionFactory getReflectionFactory() {
3418 var factory = reflectionFactory;
3419 if (factory != null) {
3420 return factory;
3421 }
3422 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3423 }
3424 private static ReflectionFactory reflectionFactory;
3425
3426 /**
3427 * When CDS is enabled, the Class class may be aot-initialized. However,
3428 * we can't archive reflectionFactory, so we reset it to null, so it
3429 * will be allocated again at runtime.
3430 */
3431 private static void resetArchivedStates() {
3432 reflectionFactory = null;
3433 }
3434
3435 /**
3436 * Returns the elements of this enum class or null if this
3437 * Class object does not represent an enum class.
3438 *
3439 * @return an array containing the values comprising the enum class
3440 * represented by this {@code Class} object in the order they're
3441 * declared, or null if this {@code Class} object does not
3442 * represent an enum class
3443 * @since 1.5
3444 * @jls 8.9.1 Enum Constants
3445 */
3446 public T[] getEnumConstants() {
3447 T[] values = getEnumConstantsShared();
3448 return (values != null) ? values.clone() : null;
3449 }
3450
3451 /**
3452 * Returns the elements of this enum class or null if this
3453 * Class object does not represent an enum class;
3454 * identical to getEnumConstants except that the result is
3455 * uncloned, cached, and shared by all callers.
3456 */
3457 T[] getEnumConstantsShared() {
3458 T[] constants = enumConstants;
3459 if (constants == null) {
3460 if (!isEnum()) return null;
3461 try {
3462 final Method values = getMethod("values");
3463 values.setAccessible(true);
3464 @SuppressWarnings("unchecked")
3465 T[] temporaryConstants = (T[])values.invoke(null);
3466 enumConstants = constants = temporaryConstants;
3467 }
3468 // These can happen when users concoct enum-like classes
3469 // that don't comply with the enum spec.
3470 catch (InvocationTargetException | NoSuchMethodException |
3471 IllegalAccessException | NullPointerException |
3472 ClassCastException ex) { return null; }
3473 }
3474 return constants;
3475 }
3476 private transient volatile T[] enumConstants;
3477
3478 /**
3479 * Returns a map from simple name to enum constant. This package-private
3480 * method is used internally by Enum to implement
3481 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3482 * efficiently. Note that the map is returned by this method is
3483 * created lazily on first use. Typically it won't ever get created.
3484 */
3485 Map<String, T> enumConstantDirectory() {
3486 Map<String, T> directory = enumConstantDirectory;
3487 if (directory == null) {
3488 T[] universe = getEnumConstantsShared();
3489 if (universe == null)
3490 throw new IllegalArgumentException(
3491 getName() + " is not an enum class");
3492 directory = HashMap.newHashMap(universe.length);
3493 for (T constant : universe) {
3494 directory.put(((Enum<?>)constant).name(), constant);
3495 }
3496 enumConstantDirectory = directory;
3497 }
3498 return directory;
3499 }
3500 private transient volatile Map<String, T> enumConstantDirectory;
3501
3502 /**
3503 * Casts an object to the class or interface represented
3504 * by this {@code Class} object.
3505 *
3506 * @param obj the object to be cast, may be {@code null}
3507 * @return the object after casting, or null if obj is null
3508 *
3509 * @throws ClassCastException if the object is not
3510 * null and is not assignable to the type T.
3511 *
3512 * @since 1.5
3513 */
3514 @SuppressWarnings("unchecked")
3515 @IntrinsicCandidate
3516 public T cast(Object obj) {
3517 if (obj != null && !isInstance(obj))
3518 throw new ClassCastException(cannotCastMsg(obj));
3519 return (T) obj;
3520 }
3521
3522 private String cannotCastMsg(Object obj) {
3523 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3524 }
3525
3526 /**
3527 * Casts this {@code Class} object to represent a subclass of the class
3528 * represented by the specified class object. Checks that the cast
3529 * is valid, and throws a {@code ClassCastException} if it is not. If
3530 * this method succeeds, it always returns a reference to this {@code Class} object.
3531 *
3532 * <p>This method is useful when a client needs to "narrow" the type of
3533 * a {@code Class} object to pass it to an API that restricts the
3534 * {@code Class} objects that it is willing to accept. A cast would
3535 * generate a compile-time warning, as the correctness of the cast
3536 * could not be checked at runtime (because generic types are implemented
3537 * by erasure).
3538 *
3539 * @param <U> the type to cast this {@code Class} object to
3540 * @param clazz the class of the type to cast this {@code Class} object to
3541 * @return this {@code Class} object, cast to represent a subclass of
3542 * the specified class object.
3543 * @throws ClassCastException if this {@code Class} object does not
3544 * represent a subclass of the specified class (here "subclass" includes
3545 * the class itself).
3546 * @since 1.5
3547 */
3548 @SuppressWarnings("unchecked")
3549 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3550 if (clazz.isAssignableFrom(this))
3551 return (Class<? extends U>) this;
3552 else
3553 throw new ClassCastException(this.toString());
3554 }
3555
3556 /**
3557 * {@inheritDoc}
3558 * <p>Note that any annotation returned by this method is a
3559 * declaration annotation.
3560 *
3561 * @since 1.5
3562 */
3563 @Override
3564 @SuppressWarnings("unchecked")
3565 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3566 Objects.requireNonNull(annotationClass);
3567
3568 return (A) annotationData().annotations.get(annotationClass);
3569 }
3570
3571 /**
3572 * {@inheritDoc}
3573 * @since 1.5
3574 */
3575 @Override
3576 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3577 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3578 }
3579
3580 /**
3581 * {@inheritDoc}
3582 * <p>Note that any annotations returned by this method are
3583 * declaration annotations.
3584 *
3585 * @since 1.8
3586 */
3587 @Override
3588 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3589 Objects.requireNonNull(annotationClass);
3590
3591 AnnotationData annotationData = annotationData();
3592 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3593 this,
3594 annotationClass);
3595 }
3596
3597 /**
3598 * {@inheritDoc}
3599 * <p>Note that any annotations returned by this method are
3600 * declaration annotations.
3601 *
3602 * @since 1.5
3603 */
3604 @Override
3605 public Annotation[] getAnnotations() {
3606 return AnnotationParser.toArray(annotationData().annotations);
3607 }
3608
3609 /**
3610 * {@inheritDoc}
3611 * <p>Note that any annotation returned by this method is a
3612 * declaration annotation.
3613 *
3614 * @since 1.8
3615 */
3616 @Override
3617 @SuppressWarnings("unchecked")
3618 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3619 Objects.requireNonNull(annotationClass);
3620
3621 return (A) annotationData().declaredAnnotations.get(annotationClass);
3622 }
3623
3624 /**
3625 * {@inheritDoc}
3626 * <p>Note that any annotations returned by this method are
3627 * declaration annotations.
3628 *
3629 * @since 1.8
3630 */
3631 @Override
3632 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3633 Objects.requireNonNull(annotationClass);
3634
3635 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3636 annotationClass);
3637 }
3638
3639 /**
3640 * {@inheritDoc}
3641 * <p>Note that any annotations returned by this method are
3642 * declaration annotations.
3643 *
3644 * @since 1.5
3645 */
3646 @Override
3647 public Annotation[] getDeclaredAnnotations() {
3648 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3649 }
3650
3651 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3652 private static class AnnotationData {
3653 final Map<Class<? extends Annotation>, Annotation> annotations;
3654 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3655
3656 // Value of classRedefinedCount when we created this AnnotationData instance
3657 final int redefinedCount;
3658
3659 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3660 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3661 int redefinedCount) {
3662 this.annotations = annotations;
3663 this.declaredAnnotations = declaredAnnotations;
3664 this.redefinedCount = redefinedCount;
3665 }
3666 }
3667
3668 // Annotations cache
3669 @SuppressWarnings("UnusedDeclaration")
3670 private transient volatile AnnotationData annotationData;
3671
3672 private AnnotationData annotationData() {
3673 while (true) { // retry loop
3674 AnnotationData annotationData = this.annotationData;
3675 int classRedefinedCount = this.classRedefinedCount;
3676 if (annotationData != null &&
3677 annotationData.redefinedCount == classRedefinedCount) {
3678 return annotationData;
3679 }
3680 // null or stale annotationData -> optimistically create new instance
3681 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3682 // try to install it
3683 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3684 // successfully installed new AnnotationData
3685 return newAnnotationData;
3686 }
3687 }
3688 }
3689
3690 private AnnotationData createAnnotationData(int classRedefinedCount) {
3691 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3692 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3693 Class<?> superClass = getSuperclass();
3694 Map<Class<? extends Annotation>, Annotation> annotations = null;
3695 if (superClass != null) {
3696 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3697 superClass.annotationData().annotations;
3698 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3699 Class<? extends Annotation> annotationClass = e.getKey();
3700 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3701 if (annotations == null) { // lazy construction
3702 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3703 declaredAnnotations.size(),
3704 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3705 )
3706 );
3707 }
3708 annotations.put(annotationClass, e.getValue());
3709 }
3710 }
3711 }
3712 if (annotations == null) {
3713 // no inherited annotations -> share the Map with declaredAnnotations
3714 annotations = declaredAnnotations;
3715 } else {
3716 // at least one inherited annotation -> declared may override inherited
3717 annotations.putAll(declaredAnnotations);
3718 }
3719 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3720 }
3721
3722 // Annotation interfaces cache their internal (AnnotationType) form
3723
3724 @SuppressWarnings("UnusedDeclaration")
3725 private transient volatile AnnotationType annotationType;
3726
3727 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3728 return Atomic.casAnnotationType(this, oldType, newType);
3729 }
3730
3731 AnnotationType getAnnotationType() {
3732 return annotationType;
3733 }
3734
3735 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3736 return annotationData().declaredAnnotations;
3737 }
3738
3739 /* Backing store of user-defined values pertaining to this class.
3740 * Maintained by the ClassValue class.
3741 */
3742 transient ClassValue.ClassValueMap classValueMap;
3743
3744 /**
3745 * Returns an {@code AnnotatedType} object that represents the use of a
3746 * type to specify the superclass of the entity represented by this {@code
3747 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3748 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3749 * Foo.)
3750 *
3751 * <p> If this {@code Class} object represents a class whose declaration
3752 * does not explicitly indicate an annotated superclass, then the return
3753 * value is an {@code AnnotatedType} object representing an element with no
3754 * annotations.
3755 *
3756 * <p> If this {@code Class} represents either the {@code Object} class, an
3757 * interface type, an array type, a primitive type, or void, the return
3758 * value is {@code null}.
3759 *
3760 * @return an object representing the superclass
3761 * @since 1.8
3762 */
3763 public AnnotatedType getAnnotatedSuperclass() {
3764 if (this == Object.class ||
3765 isInterface() ||
3766 isArray() ||
3767 isPrimitive() ||
3768 this == Void.TYPE) {
3769 return null;
3770 }
3771
3772 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3773 }
3774
3775 /**
3776 * Returns an array of {@code AnnotatedType} objects that represent the use
3777 * of types to specify superinterfaces of the entity represented by this
3778 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3779 * superinterface in '... implements Foo' is distinct from the
3780 * <em>declaration</em> of interface Foo.)
3781 *
3782 * <p> If this {@code Class} object represents a class, the return value is
3783 * an array containing objects representing the uses of interface types to
3784 * specify interfaces implemented by the class. The order of the objects in
3785 * the array corresponds to the order of the interface types used in the
3786 * 'implements' clause of the declaration of this {@code Class} object.
3787 *
3788 * <p> If this {@code Class} object represents an interface, the return
3789 * value is an array containing objects representing the uses of interface
3790 * types to specify interfaces directly extended by the interface. The
3791 * order of the objects in the array corresponds to the order of the
3792 * interface types used in the 'extends' clause of the declaration of this
3793 * {@code Class} object.
3794 *
3795 * <p> If this {@code Class} object represents a class or interface whose
3796 * declaration does not explicitly indicate any annotated superinterfaces,
3797 * the return value is an array of length 0.
3798 *
3799 * <p> If this {@code Class} object represents either the {@code Object}
3800 * class, an array type, a primitive type, or void, the return value is an
3801 * array of length 0.
3802 *
3803 * @return an array representing the superinterfaces
3804 * @since 1.8
3805 */
3806 public AnnotatedType[] getAnnotatedInterfaces() {
3807 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3808 }
3809
3810 private native Class<?> getNestHost0();
3811
3812 /**
3813 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3814 * or interface represented by this {@code Class} object belongs.
3815 * Every class and interface belongs to exactly one nest.
3816 *
3817 * If the nest host of this class or interface has previously
3818 * been determined, then this method returns the nest host.
3819 * If the nest host of this class or interface has
3820 * not previously been determined, then this method determines the nest
3821 * host using the algorithm of JVMS 5.4.4, and returns it.
3822 *
3823 * Often, a class or interface belongs to a nest consisting only of itself,
3824 * in which case this method returns {@code this} to indicate that the class
3825 * or interface is the nest host.
3826 *
3827 * <p>If this {@code Class} object represents a primitive type, an array type,
3828 * or {@code void}, then this method returns {@code this},
3829 * indicating that the represented entity belongs to the nest consisting only of
3830 * itself, and is the nest host.
3831 *
3832 * @return the nest host of this class or interface
3833 *
3834 * @since 11
3835 * @jvms 4.7.28 The {@code NestHost} Attribute
3836 * @jvms 4.7.29 The {@code NestMembers} Attribute
3837 * @jvms 5.4.4 Access Control
3838 */
3839 public Class<?> getNestHost() {
3840 if (isPrimitive() || isArray()) {
3841 return this;
3842 }
3843 return getNestHost0();
3844 }
3845
3846 /**
3847 * Determines if the given {@code Class} is a nestmate of the
3848 * class or interface represented by this {@code Class} object.
3849 * Two classes or interfaces are nestmates
3850 * if they have the same {@linkplain #getNestHost() nest host}.
3851 *
3852 * @param c the class to check
3853 * @return {@code true} if this class and {@code c} are members of
3854 * the same nest; and {@code false} otherwise.
3855 *
3856 * @since 11
3857 */
3858 public boolean isNestmateOf(Class<?> c) {
3859 Objects.requireNonNull(c);
3860 if (this == c) {
3861 return true;
3862 }
3863 if (isPrimitive() || isArray() ||
3864 c.isPrimitive() || c.isArray()) {
3865 return false;
3866 }
3867
3868 return getNestHost() == c.getNestHost();
3869 }
3870
3871 private native Class<?>[] getNestMembers0();
3872
3873 /**
3874 * Returns an array containing {@code Class} objects representing all the
3875 * classes and interfaces that are members of the nest to which the class
3876 * or interface represented by this {@code Class} object belongs.
3877 *
3878 * First, this method obtains the {@linkplain #getNestHost() nest host},
3879 * {@code H}, of the nest to which the class or interface represented by
3880 * this {@code Class} object belongs. The zeroth element of the returned
3881 * array is {@code H}.
3882 *
3883 * Then, for each class or interface {@code C} which is recorded by {@code H}
3884 * as being a member of its nest, this method attempts to obtain the {@code Class}
3885 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3886 * loader} of the current {@code Class} object), and then obtains the
3887 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3888 * The classes and interfaces which are recorded by {@code H} as being members
3889 * of its nest, and for which {@code H} can be determined as their nest host,
3890 * are indicated by subsequent elements of the returned array. The order of
3891 * such elements is unspecified. Duplicates are permitted.
3892 *
3893 * <p>If this {@code Class} object represents a primitive type, an array type,
3894 * or {@code void}, then this method returns a single-element array containing
3895 * {@code this}.
3896 *
3897 * @apiNote
3898 * The returned array includes only the nest members recorded in the {@code NestMembers}
3899 * attribute, and not any hidden classes that were added to the nest via
3900 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3901 * Lookup::defineHiddenClass}.
3902 *
3903 * @return an array of all classes and interfaces in the same nest as
3904 * this class or interface
3905 *
3906 * @since 11
3907 * @see #getNestHost()
3908 * @jvms 4.7.28 The {@code NestHost} Attribute
3909 * @jvms 4.7.29 The {@code NestMembers} Attribute
3910 */
3911 public Class<?>[] getNestMembers() {
3912 if (isPrimitive() || isArray()) {
3913 return new Class<?>[] { this };
3914 }
3915 Class<?>[] members = getNestMembers0();
3916 // Can't actually enable this due to bootstrapping issues
3917 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3918 return members;
3919 }
3920
3921 /**
3922 * Returns the descriptor string of the entity (class, interface, array class,
3923 * primitive type, or {@code void}) represented by this {@code Class} object.
3924 *
3925 * <p> If this {@code Class} object represents a class or interface,
3926 * not an array class, then:
3927 * <ul>
3928 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3929 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3930 * for the class or interface. Calling
3931 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3932 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3933 * describing this class or interface.
3934 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3935 * then the result is a string of the form:
3936 * <blockquote>
3937 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3938 * </blockquote>
3939 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3940 * encoded in internal form indicated by the {@code class} file passed to
3941 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3942 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3943 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3944 * The result string is not a type descriptor.
3945 * </ul>
3946 *
3947 * <p> If this {@code Class} object represents an array class, then
3948 * the result is a string consisting of one or more '{@code [}' characters
3949 * representing the depth of the array nesting, followed by the
3950 * descriptor string of the element type.
3951 * <ul>
3952 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3953 * or interface, then this array class can be described nominally.
3954 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3955 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3956 * describing this array class.
3957 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3958 * interface, then this array class cannot be described nominally.
3959 * The result string is not a type descriptor.
3960 * </ul>
3961 *
3962 * <p> If this {@code Class} object represents a primitive type or
3963 * {@code void}, then the result is a field descriptor string which
3964 * is a one-letter code corresponding to a primitive type or {@code void}
3965 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3966 *
3967 * @return the descriptor string for this {@code Class} object
3968 * @jvms 4.3.2 Field Descriptors
3969 * @since 12
3970 */
3971 @Override
3972 public String descriptorString() {
3973 if (isPrimitive())
3974 return Wrapper.forPrimitiveType(this).basicTypeString();
3975
3976 if (isArray()) {
3977 return "[".concat(componentType.descriptorString());
3978 } else if (isHidden()) {
3979 String name = getName();
3980 int index = name.indexOf('/');
3981 return new StringBuilder(name.length() + 2)
3982 .append('L')
3983 .append(name.substring(0, index).replace('.', '/'))
3984 .append('.')
3985 .append(name, index + 1, name.length())
3986 .append(';')
3987 .toString();
3988 } else {
3989 String name = getName().replace('.', '/');
3990 return StringConcatHelper.concat("L", name, ";");
3991 }
3992 }
3993
3994 /**
3995 * Returns the component type of this {@code Class}, if it describes
3996 * an array type, or {@code null} otherwise.
3997 *
3998 * @implSpec
3999 * Equivalent to {@link Class#getComponentType()}.
4000 *
4001 * @return a {@code Class} describing the component type, or {@code null}
4002 * if this {@code Class} does not describe an array type
4003 * @since 12
4004 */
4005 @Override
4006 public Class<?> componentType() {
4007 return getComponentType();
4008 }
4009
4010 /**
4011 * Returns a {@code Class} for an array type whose component type
4012 * is described by this {@linkplain Class}.
4013 *
4014 * @throws UnsupportedOperationException if this component type is {@linkplain
4015 * Void#TYPE void} or if the number of dimensions of the resulting array
4016 * type would exceed 255.
4017 * @return a {@code Class} describing the array type
4018 * @jvms 4.3.2 Field Descriptors
4019 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4020 * @since 12
4021 */
4022 @Override
4023 public Class<?> arrayType() {
4024 try {
4025 return Array.newInstance(this, 0).getClass();
4026 } catch (IllegalArgumentException iae) {
4027 throw new UnsupportedOperationException(iae);
4028 }
4029 }
4030
4031 /**
4032 * Returns a nominal descriptor for this instance, if one can be
4033 * constructed, or an empty {@link Optional} if one cannot be.
4034 *
4035 * @return An {@link Optional} containing the resulting nominal descriptor,
4036 * or an empty {@link Optional} if one cannot be constructed.
4037 * @since 12
4038 */
4039 @Override
4040 public Optional<ClassDesc> describeConstable() {
4041 Class<?> c = isArray() ? elementType() : this;
4042 return c.isHidden() ? Optional.empty()
4043 : Optional.of(ConstantUtils.classDesc(this));
4044 }
4045
4046 /**
4047 * Returns {@code true} if and only if the underlying class is a hidden class.
4048 *
4049 * @return {@code true} if and only if this class is a hidden class.
4050 *
4051 * @since 15
4052 * @see MethodHandles.Lookup#defineHiddenClass
4053 * @see Class##hiddenClasses Hidden Classes
4054 */
4055 @IntrinsicCandidate
4056 public native boolean isHidden();
4057
4058 /**
4059 * Returns an array containing {@code Class} objects representing the
4060 * direct subinterfaces or subclasses permitted to extend or
4061 * implement this class or interface if it is sealed. The order of such elements
4062 * is unspecified. The array is empty if this sealed class or interface has no
4063 * permitted subclass. If this {@code Class} object represents a primitive type,
4064 * {@code void}, an array type, or a class or interface that is not sealed,
4065 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4066 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4067 * returns a non-null value.
4068 *
4069 * For each class or interface {@code C} which is recorded as a permitted
4070 * direct subinterface or subclass of this class or interface,
4071 * this method attempts to obtain the {@code Class}
4072 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4073 * loader} of the current {@code Class} object).
4074 * The {@code Class} objects which can be obtained and which are direct
4075 * subinterfaces or subclasses of this class or interface,
4076 * are indicated by elements of the returned array. If a {@code Class} object
4077 * cannot be obtained, it is silently ignored, and not included in the result
4078 * array.
4079 *
4080 * @return an array of {@code Class} objects of the permitted subclasses of this class
4081 * or interface, or {@code null} if this class or interface is not sealed.
4082 *
4083 * @jls 8.1 Class Declarations
4084 * @jls 9.1 Interface Declarations
4085 * @since 17
4086 */
4087 public Class<?>[] getPermittedSubclasses() {
4088 Class<?>[] subClasses;
4089 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4090 return null;
4091 }
4092 if (subClasses.length > 0) {
4093 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4094 subClasses = Arrays.stream(subClasses)
4095 .filter(this::isDirectSubType)
4096 .toArray(s -> new Class<?>[s]);
4097 }
4098 }
4099 return subClasses;
4100 }
4101
4102 private boolean isDirectSubType(Class<?> c) {
4103 if (isInterface()) {
4104 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4105 if (i == this) {
4106 return true;
4107 }
4108 }
4109 } else {
4110 return c.getSuperclass() == this;
4111 }
4112 return false;
4113 }
4114
4115 /**
4116 * Returns {@code true} if and only if this {@code Class} object represents
4117 * a sealed class or interface. If this {@code Class} object represents a
4118 * primitive type, {@code void}, or an array type, this method returns
4119 * {@code false}. A sealed class or interface has (possibly zero) permitted
4120 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4121 * possibly empty value for a sealed class or interface.
4122 *
4123 * @return {@code true} if and only if this {@code Class} object represents
4124 * a sealed class or interface.
4125 *
4126 * @jls 8.1 Class Declarations
4127 * @jls 9.1 Interface Declarations
4128 * @since 17
4129 */
4130 public boolean isSealed() {
4131 if (isArray() || isPrimitive()) {
4132 return false;
4133 }
4134 return getPermittedSubclasses() != null;
4135 }
4136
4137 private native Class<?>[] getPermittedSubclasses0();
4138
4139 /*
4140 * Return the class's major and minor class file version packed into an int.
4141 * The high order 16 bits contain the class's minor version. The low order
4142 * 16 bits contain the class's major version.
4143 *
4144 * If the class is an array type then the class file version of its element
4145 * type is returned. If the class is a primitive type then the latest class
4146 * file major version is returned and zero is returned for the minor version.
4147 */
4148 int getClassFileVersion() {
4149 Class<?> c = isArray() ? elementType() : this;
4150 return c.getClassFileVersion0();
4151 }
4152
4153 private native int getClassFileVersion0();
4154
4155 /**
4156 * Return the access flags as they were in the class's bytecode, including
4157 * the original setting of ACC_SUPER.
4158 *
4159 * If this {@code Class} object represents a primitive type or
4160 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
4161 * {@code FINAL}.
4162 * If this {@code Class} object represents an array type, return 0.
4163 */
4164 int getClassFileAccessFlags() {
4165 return classFileAccessFlags;
4166 }
4167
4168 // Validates the length of the class name and throws an exception if it exceeds the maximum allowed length.
4169 private static void validateClassNameLength(String name) throws ClassNotFoundException {
4170 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
4171 throw new ClassNotFoundException(
4172 "Class name length exceeds limit of "
4173 + ModifiedUtf.CONSTANT_POOL_UTF8_MAX_BYTES
4174 + ": " + name.substring(0,256) + "...");
4175 }
4176 }
4177
4178 // Support for "OLD" CDS workflow -- {
4179 private static final int RD_PUBLIC_METHODS = (1 << 0);
4180 private static final int RD_PUBLIC_FIELDS = (1 << 1);
4181 private static final int RD_DECLARED_CTORS = (1 << 2);
4182 private static final int RD_PUBLIC_CTORS = (1 << 3);
4183 private static final int RD_DECLARED_METHODS = (1 << 4);
4184 private static final int RD_DECLARED_PUBLIC_METHODS = (1 << 5);
4185 private static final int RD_DECLARED_FIELDS = (1 << 6);
4186 private static final int RD_DECLARED_PUBLIC_FIELDS = (1 << 7);
4187 private static final int RD_DECLARED_INTERFACES = (1 << 8);
4188 private static final int RD_DECLARED_SIMPLE_NAME = (1 << 9);
4189 private static final int RD_DECLARED_CANONICAL_NAME = (1 << 10);
4190 private static final int CLS_NAME = (1 << 10);
4191
4192
4193 private int encodeReflectionData() {
4194 int flags = CLS_NAME;
4195 if (reflectionData != null) {
4196 flags = (reflectionData.publicMethods != null ? RD_PUBLIC_METHODS : 0) |
4197 (reflectionData.publicFields != null ? RD_PUBLIC_FIELDS : 0) |
4198 (reflectionData.declaredConstructors != null ? RD_DECLARED_CTORS : 0) |
4199 (reflectionData.publicConstructors != null ? RD_PUBLIC_CTORS : 0) |
4200 (reflectionData.declaredMethods != null ? RD_DECLARED_METHODS : 0) |
4201 (reflectionData.declaredPublicMethods != null ? RD_DECLARED_PUBLIC_METHODS : 0) |
4202 (reflectionData.declaredFields != null ? RD_DECLARED_FIELDS : 0) |
4203 (reflectionData.declaredPublicFields != null ? RD_DECLARED_PUBLIC_FIELDS : 0) |
4204 (reflectionData.interfaces != null ? RD_DECLARED_INTERFACES : 0) |
4205 (reflectionData.simpleName != null ? RD_DECLARED_SIMPLE_NAME : 0) |
4206 (reflectionData.canonicalName != null ? RD_DECLARED_CANONICAL_NAME : 0);
4207 }
4208 return flags;
4209 }
4210 private void generateReflectionData(int flags) {
4211 if ((flags & CLS_NAME ) != 0) { getName(); } // String name
4212 if ((flags & RD_PUBLIC_METHODS ) != 0) { privateGetPublicMethods(); } // Method[] publicMethods;
4213 if ((flags & RD_PUBLIC_FIELDS ) != 0) { privateGetPublicFields(); } // Field[] publicFields;
4214 if ((flags & RD_DECLARED_CTORS ) != 0) { privateGetDeclaredConstructors(false); } // Constructor<T>[] declaredConstructors;
4215 if ((flags & RD_PUBLIC_CTORS ) != 0) { privateGetDeclaredConstructors(true); } // Constructor<T>[] publicConstructors;
4216 if ((flags & RD_DECLARED_METHODS ) != 0) { privateGetDeclaredMethods(false); } // Method[] declaredMethods;
4217 if ((flags & RD_DECLARED_PUBLIC_METHODS) != 0) { privateGetDeclaredMethods(true); } // Method[] declaredPublicMethods;
4218 if ((flags & RD_DECLARED_FIELDS ) != 0) { privateGetDeclaredFields(false); } // Field[] declaredFields;
4219 if ((flags & RD_DECLARED_PUBLIC_FIELDS ) != 0) { privateGetDeclaredFields(true); } // Field[] declaredPublicFields;
4220 if ((flags & RD_DECLARED_INTERFACES ) != 0) { getInterfaces(false); } // Class<?>[] interfaces;
4221 if ((flags & RD_DECLARED_SIMPLE_NAME ) != 0) { getSimpleName(); } // String simpleName;
4222 if ((flags & RD_DECLARED_CANONICAL_NAME) != 0) { getCanonicalName(); } // String canonicalName;
4223 }
4224
4225 // -- }
4226 }