1 /*
2 * Copyright (c) 1994, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.constant.ClassDesc;
30 import java.lang.constant.ConstantDescs;
31 import java.lang.invoke.TypeDescriptor;
32 import java.lang.invoke.MethodHandles;
33 import java.lang.ref.SoftReference;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.ObjectStreamField;
37 import java.lang.reflect.AnnotatedElement;
38 import java.lang.reflect.AnnotatedType;
39 import java.lang.reflect.AccessFlag;
40 import java.lang.reflect.Array;
41 import java.lang.reflect.Constructor;
42 import java.lang.reflect.Executable;
43 import java.lang.reflect.Field;
44 import java.lang.reflect.GenericArrayType;
45 import java.lang.reflect.GenericDeclaration;
46 import java.lang.reflect.InvocationTargetException;
47 import java.lang.reflect.Member;
48 import java.lang.reflect.Method;
49 import java.lang.reflect.Modifier;
50 import java.lang.reflect.Proxy;
51 import java.lang.reflect.RecordComponent;
52 import java.lang.reflect.Type;
53 import java.lang.reflect.TypeVariable;
54 import java.lang.constant.Constable;
55 import java.net.URL;
56 import java.security.Permissions;
57 import java.security.ProtectionDomain;
58 import java.util.ArrayList;
59 import java.util.Arrays;
60 import java.util.Collection;
61 import java.util.HashMap;
62 import java.util.HashSet;
63 import java.util.LinkedHashMap;
64 import java.util.LinkedHashSet;
65 import java.util.List;
66 import java.util.Map;
67 import java.util.Objects;
68 import java.util.Optional;
69 import java.util.Set;
70 import java.util.stream.Collectors;
71
72 import jdk.internal.constant.ConstantUtils;
73 import jdk.internal.loader.BootLoader;
74 import jdk.internal.loader.BuiltinClassLoader;
75 import jdk.internal.misc.Unsafe;
76 import jdk.internal.module.Resources;
77 import jdk.internal.reflect.CallerSensitive;
78 import jdk.internal.reflect.CallerSensitiveAdapter;
79 import jdk.internal.reflect.ConstantPool;
80 import jdk.internal.reflect.Reflection;
81 import jdk.internal.reflect.ReflectionFactory;
82 import jdk.internal.vm.annotation.IntrinsicCandidate;
83 import jdk.internal.vm.annotation.Stable;
84
85 import sun.invoke.util.Wrapper;
86 import sun.reflect.generics.factory.CoreReflectionFactory;
87 import sun.reflect.generics.factory.GenericsFactory;
88 import sun.reflect.generics.repository.ClassRepository;
89 import sun.reflect.generics.repository.MethodRepository;
90 import sun.reflect.generics.repository.ConstructorRepository;
91 import sun.reflect.generics.scope.ClassScope;
92 import sun.security.util.SecurityConstants;
93 import sun.reflect.annotation.*;
94 import sun.reflect.misc.ReflectUtil;
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 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
164 * A class or interface created by the invocation of
165 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
166 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
167 * class or interface.
168 * All kinds of class, including enum classes and record classes, may be
169 * hidden classes; all kinds of interface, including annotation interfaces,
170 * may be hidden interfaces.
171 *
172 * The {@linkplain #getName() name of a hidden class or interface} is
173 * not a {@linkplain ClassLoader##binary-name binary name},
174 * which means the following:
175 * <ul>
176 * <li>A hidden class or interface cannot be referenced by the constant pools
177 * of other classes and interfaces.
178 * <li>A hidden class or interface cannot be described in
179 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
180 * {@link #describeConstable() Class::describeConstable},
181 * {@link ClassDesc#of(String) ClassDesc::of}, or
182 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
183 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
184 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
185 * </ul>
186 *
187 * A hidden class or interface is never an array class, but may be
188 * the element type of an array. In all other respects, the fact that
189 * a class or interface is hidden has no bearing on the characteristics
190 * exposed by the methods of class {@code Class}.
191 *
192 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
193 *
194 * Conventionally, a Java compiler, starting from a source file for an
195 * implicitly declared class, say {@code HelloWorld.java}, creates a
196 * similarly-named {@code class} file, {@code HelloWorld.class}, where
197 * the class stored in that {@code class} file is named {@code
198 * "HelloWorld"}, matching the base names of the source and {@code
199 * class} files.
200 *
201 * For the {@code Class} object of an implicitly declared class {@code
202 * HelloWorld}, the methods to get the {@linkplain #getName name} and
203 * {@linkplain #getTypeName type name} return results
204 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
205 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
206 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
207 *
208 * @param <T> the type of the class modeled by this {@code Class}
209 * object. For example, the type of {@code String.class} is {@code
210 * Class<String>}. Use {@code Class<?>} if the class being modeled is
211 * unknown.
212 *
213 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
214 * @since 1.0
215 */
216 public final class Class<T> implements java.io.Serializable,
217 GenericDeclaration,
218 Type,
219 AnnotatedElement,
220 TypeDescriptor.OfField<Class<?>>,
221 Constable {
222 private static final int ANNOTATION= 0x00002000;
223 private static final int ENUM = 0x00004000;
224 private static final int SYNTHETIC = 0x00001000;
225
226 private static native void registerNatives();
227 static {
228 runtimeSetup();
229 }
230
231 // Called from JVM when loading an AOT cache
232 private static void runtimeSetup() {
233 registerNatives();
234 }
235
236 /*
237 * Private constructor. Only the Java Virtual Machine creates Class objects.
238 * This constructor is not used and prevents the default constructor being
239 * generated.
240 */
241 private Class(ClassLoader loader, Class<?> arrayComponentType) {
242 // Initialize final field for classLoader. The initialization value of non-null
243 // prevents future JIT optimizations from assuming this final field is null.
244 classLoader = loader;
245 componentType = arrayComponentType;
246 }
247
248 /**
249 * Converts the object to a string. The string representation is the
250 * string "class" or "interface", followed by a space, and then by the
251 * name of the class in the format returned by {@code getName}.
252 * If this {@code Class} object represents a primitive type,
253 * this method returns the name of the primitive type. If
254 * this {@code Class} object represents void this method returns
255 * "void". If this {@code Class} object represents an array type,
256 * this method returns "class " followed by {@code getName}.
257 *
258 * @return a string representation of this {@code Class} object.
259 */
260 public String toString() {
261 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
262 return kind.concat(getName());
263 }
264
265 /**
266 * Returns a string describing this {@code Class}, including
267 * information about modifiers, {@link #isSealed() sealed}/{@code
268 * non-sealed} status, and type parameters.
269 *
270 * The string is formatted as a list of type modifiers, if any,
271 * followed by the kind of type (empty string for primitive types
272 * and {@code class}, {@code enum}, {@code interface},
273 * {@code @interface}, or {@code record} as appropriate), followed
274 * by the type's name, followed by an angle-bracketed
275 * comma-separated list of the type's type parameters, if any,
276 * including informative bounds on the type parameters, if any.
277 *
278 * A space is used to separate modifiers from one another and to
279 * separate any modifiers from the kind of type. The modifiers
280 * occur in canonical order. If there are no type parameters, the
281 * type parameter list is elided.
282 *
283 * For an array type, the string starts with the type name,
284 * followed by an angle-bracketed comma-separated list of the
285 * type's type parameters, if any, followed by a sequence of
286 * {@code []} characters, one set of brackets per dimension of
287 * the array.
288 *
289 * <p>Note that since information about the runtime representation
290 * of a type is being generated, modifiers not present on the
291 * originating source code or illegal on the originating source
292 * code may be present.
293 *
294 * @return a string describing this {@code Class}, including
295 * information about modifiers and type parameters
296 *
297 * @since 1.8
298 */
299 public String toGenericString() {
300 if (isPrimitive()) {
301 return toString();
302 } else {
303 StringBuilder sb = new StringBuilder();
304 Class<?> component = this;
305 int arrayDepth = 0;
306
307 if (isArray()) {
308 do {
309 arrayDepth++;
310 component = component.getComponentType();
311 } while (component.isArray());
312 sb.append(component.getName());
313 } else {
314 // Class modifiers are a superset of interface modifiers
315 int modifiers = getModifiers() & Modifier.classModifiers();
316 if (modifiers != 0) {
317 sb.append(Modifier.toString(modifiers));
318 sb.append(' ');
319 }
320
321 // A class cannot be strictfp and sealed/non-sealed so
322 // it is sufficient to check for sealed-ness after all
323 // modifiers are printed.
324 addSealingInfo(modifiers, sb);
325
326 if (isAnnotation()) {
327 sb.append('@');
328 }
329 if (isInterface()) { // Note: all annotation interfaces are interfaces
330 sb.append("interface");
331 } else {
332 if (isEnum())
333 sb.append("enum");
334 else if (isRecord())
335 sb.append("record");
336 else
337 sb.append("class");
338 }
339 sb.append(' ');
340 sb.append(getName());
341 }
342
343 TypeVariable<?>[] typeparms = component.getTypeParameters();
344 if (typeparms.length > 0) {
345 sb.append(Arrays.stream(typeparms)
346 .map(Class::typeVarBounds)
347 .collect(Collectors.joining(",", "<", ">")));
348 }
349
350 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
351
352 return sb.toString();
353 }
354 }
355
356 private void addSealingInfo(int modifiers, StringBuilder sb) {
357 // A class can be final XOR sealed XOR non-sealed.
358 if (Modifier.isFinal(modifiers)) {
359 return; // no-op
360 } else {
361 if (isSealed()) {
362 sb.append("sealed ");
363 return;
364 } else {
365 // Check for sealed ancestor, which implies this class
366 // is non-sealed.
367 if (hasSealedAncestor(this)) {
368 sb.append("non-sealed ");
369 }
370 }
371 }
372 }
373
374 private boolean hasSealedAncestor(Class<?> clazz) {
375 // From JLS 8.1.1.2:
376 // "It is a compile-time error if a class has a sealed direct
377 // superclass or a sealed direct superinterface, and is not
378 // declared final, sealed, or non-sealed either explicitly or
379 // implicitly.
380 // Thus, an effect of the sealed keyword is to force all
381 // direct subclasses to explicitly declare whether they are
382 // final, sealed, or non-sealed. This avoids accidentally
383 // exposing a sealed class hierarchy to unwanted subclassing."
384
385 // Therefore, will just check direct superclass and
386 // superinterfaces.
387 var superclass = clazz.getSuperclass();
388 if (superclass != null && superclass.isSealed()) {
389 return true;
390 }
391 for (var superinterface : clazz.getInterfaces()) {
392 if (superinterface.isSealed()) {
393 return true;
394 }
395 }
396 return false;
397 }
398
399 static String typeVarBounds(TypeVariable<?> typeVar) {
400 Type[] bounds = typeVar.getBounds();
401 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
402 return typeVar.getName();
403 } else {
404 return typeVar.getName() + " extends " +
405 Arrays.stream(bounds)
406 .map(Type::getTypeName)
407 .collect(Collectors.joining(" & "));
408 }
409 }
410
411 /**
412 * Returns the {@code Class} object associated with the class or
413 * interface with the given string name. Invoking this method is
414 * equivalent to:
415 *
416 * {@snippet lang="java" :
417 * Class.forName(className, true, currentLoader)
418 * }
419 *
420 * where {@code currentLoader} denotes the defining class loader of
421 * the current class.
422 *
423 * <p> For example, the following code fragment returns the
424 * runtime {@code Class} object for the class named
425 * {@code java.lang.Thread}:
426 *
427 * {@snippet lang="java" :
428 * Class<?> t = Class.forName("java.lang.Thread");
429 * }
430 * <p>
431 * A call to {@code forName("X")} causes the class named
432 * {@code X} to be initialized.
433 *
434 * <p>
435 * In cases where this method is called from a context where there is no
436 * caller frame on the stack (e.g. when called directly from a JNI
437 * attached thread), the system class loader is used.
438 *
439 * @param className the {@linkplain ClassLoader##binary-name binary name}
440 * of the class or the string representing an array type
441 * @return the {@code Class} object for the class with the
442 * specified name.
443 * @throws LinkageError if the linkage fails
444 * @throws ExceptionInInitializerError if the initialization provoked
445 * by this method fails
446 * @throws ClassNotFoundException if the class cannot be located
447 *
448 * @jls 12.2 Loading of Classes and Interfaces
449 * @jls 12.3 Linking of Classes and Interfaces
450 * @jls 12.4 Initialization of Classes and Interfaces
451 */
452 @CallerSensitive
453 public static Class<?> forName(String className)
454 throws ClassNotFoundException {
455 Class<?> caller = Reflection.getCallerClass();
456 return forName(className, caller);
457 }
458
459 // Caller-sensitive adapter method for reflective invocation
460 @CallerSensitiveAdapter
461 private static Class<?> forName(String className, Class<?> caller)
462 throws ClassNotFoundException {
463 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
464 : ClassLoader.getClassLoader(caller);
465 if (loader instanceof BuiltinClassLoader bcl) {
466 if (bcl.usePositiveCache) {
467 Class<?> result = bcl.checkPositiveLookupCache(className);
468 if (result != null) {
469 return result;
470 }
471 }
472 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(className)) {
473 throw new ClassNotFoundException(className);
474 }
475 }
476 return forName0(className, true, loader, caller);
477 }
478
479 /**
480 * Returns the {@code Class} object associated with the class or
481 * interface with the given string name, using the given class loader.
482 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
483 * this method attempts to locate and load the class or interface. The specified
484 * class loader is used to load the class or interface. If the parameter
485 * {@code loader} is {@code null}, the class is loaded through the bootstrap
486 * class loader. The class is initialized only if the
487 * {@code initialize} parameter is {@code true} and if it has
488 * not been initialized earlier.
489 *
490 * <p> This method cannot be used to obtain any of the {@code Class} objects
491 * representing primitive types or void, hidden classes or interfaces,
492 * or array classes whose element type is a hidden class or interface.
493 * If {@code name} denotes a primitive type or void, for example {@code I},
494 * an attempt will be made to locate a user-defined class in the unnamed package
495 * whose name is {@code I} instead.
496 * To obtain a {@code Class} object for a named primitive type
497 * such as {@code int} or {@code long} use {@link
498 * #forPrimitiveName(String)}.
499 *
500 * <p> To obtain the {@code Class} object associated with an array class,
501 * the name consists of one or more {@code '['} representing the depth
502 * of the array nesting, followed by the element type as encoded in
503 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
504 *
505 * <p> Examples:
506 * {@snippet lang="java" :
507 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
508 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
509 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
510 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
511 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
512 * }
513 *
514 * <p> A call to {@code getName()} on the {@code Class} object returned
515 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
516 *
517 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
518 * named <i>N</i> to be loaded but not initialized regardless of the value
519 * of the {@code initialize} parameter.
520 *
521 * @apiNote
522 * This method throws errors related to loading, linking or initializing
523 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
524 * <cite>The Java Language Specification</cite>.
525 * In addition, this method does not check whether the requested class
526 * is accessible to its caller.
527 *
528 * @param name the {@linkplain ClassLoader##binary-name binary name}
529 * of the class or the string representing an array class
530 *
531 * @param initialize if {@code true} the class will be initialized
532 * (which implies linking). See Section {@jls
533 * 12.4} of <cite>The Java Language
534 * Specification</cite>.
535 * @param loader class loader from which the class must be loaded
536 * @return class object representing the desired class
537 *
538 * @throws LinkageError if the linkage fails
539 * @throws ExceptionInInitializerError if the initialization provoked
540 * by this method fails
541 * @throws ClassNotFoundException if the class cannot be located by
542 * the specified class loader
543 *
544 * @see java.lang.Class#forName(String)
545 * @see java.lang.ClassLoader
546 *
547 * @jls 12.2 Loading of Classes and Interfaces
548 * @jls 12.3 Linking of Classes and Interfaces
549 * @jls 12.4 Initialization of Classes and Interfaces
550 * @jls 13.1 The Form of a Binary
551 * @since 1.2
552 */
553 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
554 throws ClassNotFoundException
555 {
556 if (loader instanceof BuiltinClassLoader bcl) {
557 if (bcl.usePositiveCache) {
558 Class<?> result = bcl.checkPositiveLookupCache(name);
559 if (result != null) {
560 return result;
561 }
562 }
563 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(name)) {
564 throw new ClassNotFoundException(name);
565 }
566 }
567 return forName0(name, initialize, loader, null);
568 }
569
570 /** Called after security check for system loader access checks have been made. */
571 private static native Class<?> forName0(String name, boolean initialize,
572 ClassLoader loader,
573 Class<?> caller)
574 throws ClassNotFoundException;
575
576
577 /**
578 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
579 * binary name} in the given module.
580 *
581 * <p> This method attempts to locate and load the class or interface.
582 * It does not link the class, and does not run the class initializer.
583 * If the class is not found, this method returns {@code null}. </p>
584 *
585 * <p> If the class loader of the given module defines other modules and
586 * the given name is a class defined in a different module, this method
587 * returns {@code null} after the class is loaded. </p>
588 *
589 * <p> This method does not check whether the requested class is
590 * accessible to its caller. </p>
591 *
592 * @apiNote
593 * This method does not support loading of array types, unlike
594 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
595 * a binary name. This method returns {@code null} on failure rather than
596 * throwing a {@link ClassNotFoundException}, as is done by
597 * the {@link #forName(String, boolean, ClassLoader)} method.
598 *
599 * @param module A module
600 * @param name The {@linkplain ClassLoader##binary-name binary name}
601 * of the class
602 * @return {@code Class} object of the given name defined in the given module;
603 * {@code null} if not found.
604 *
605 * @throws NullPointerException if the given module or name is {@code null}
606 *
607 * @throws LinkageError if the linkage fails
608 *
609 * @jls 12.2 Loading of Classes and Interfaces
610 * @jls 12.3 Linking of Classes and Interfaces
611 * @since 9
612 */
613 public static Class<?> forName(Module module, String name) {
614 Objects.requireNonNull(module);
615 Objects.requireNonNull(name);
616
617 ClassLoader cl = module.getClassLoader();
618 if (cl != null) {
619 return cl.loadClass(module, name);
620 } else {
621 return BootLoader.loadClass(module, name);
622 }
623 }
624
625 /**
626 * {@return the {@code Class} object associated with the
627 * {@linkplain #isPrimitive() primitive type} of the given name}
628 * If the argument is not the name of a primitive type, {@code
629 * null} is returned.
630 *
631 * @param primitiveName the name of the primitive type to find
632 *
633 * @throws NullPointerException if the argument is {@code null}
634 *
635 * @jls 4.2 Primitive Types and Values
636 * @jls 15.8.2 Class Literals
637 * @since 22
638 */
639 public static Class<?> forPrimitiveName(String primitiveName) {
640 return switch(primitiveName) {
641 // Integral types
642 case "int" -> int.class;
643 case "long" -> long.class;
644 case "short" -> short.class;
645 case "char" -> char.class;
646 case "byte" -> byte.class;
647
648 // Floating-point types
649 case "float" -> float.class;
650 case "double" -> double.class;
651
652 // Other types
653 case "boolean" -> boolean.class;
654 case "void" -> void.class;
655
656 default -> null;
657 };
658 }
659
660 /**
661 * Creates a new instance of the class represented by this {@code Class}
662 * object. The class is instantiated as if by a {@code new}
663 * expression with an empty argument list. The class is initialized if it
664 * has not already been initialized.
665 *
666 * @deprecated This method propagates any exception thrown by the
667 * nullary constructor, including a checked exception. Use of
668 * this method effectively bypasses the compile-time exception
669 * checking that would otherwise be performed by the compiler.
670 * The {@link
671 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
672 * Constructor.newInstance} method avoids this problem by wrapping
673 * any exception thrown by the constructor in a (checked) {@link
674 * java.lang.reflect.InvocationTargetException}.
675 *
676 * <p>The call
677 *
678 * {@snippet lang="java" :
679 * clazz.newInstance()
680 * }
681 *
682 * can be replaced by
683 *
684 * {@snippet lang="java" :
685 * clazz.getDeclaredConstructor().newInstance()
686 * }
687 *
688 * The latter sequence of calls is inferred to be able to throw
689 * the additional exception types {@link
690 * InvocationTargetException} and {@link
691 * NoSuchMethodException}. Both of these exception types are
692 * subclasses of {@link ReflectiveOperationException}.
693 *
694 * @return a newly allocated instance of the class represented by this
695 * object.
696 * @throws IllegalAccessException if the class or its nullary
697 * constructor is not accessible.
698 * @throws InstantiationException
699 * if this {@code Class} represents an abstract class,
700 * an interface, an array class, a primitive type, or void;
701 * or if the class has no nullary constructor;
702 * or if the instantiation fails for some other reason.
703 * @throws ExceptionInInitializerError if the initialization
704 * provoked by this method fails.
705 */
706 @CallerSensitive
707 @Deprecated(since="9")
708 public T newInstance()
709 throws InstantiationException, IllegalAccessException
710 {
711 // Constructor lookup
712 Constructor<T> tmpConstructor = cachedConstructor;
713 if (tmpConstructor == null) {
714 if (this == Class.class) {
715 throw new IllegalAccessException(
716 "Can not call newInstance() on the Class for java.lang.Class"
717 );
718 }
719 try {
720 Class<?>[] empty = {};
721 final Constructor<T> c = getReflectionFactory().copyConstructor(
722 getConstructor0(empty, Member.DECLARED));
723 // Disable accessibility checks on the constructor
724 // access check is done with the true caller
725 c.setAccessible(true);
726 cachedConstructor = tmpConstructor = c;
727 } catch (NoSuchMethodException e) {
728 throw (InstantiationException)
729 new InstantiationException(getName()).initCause(e);
730 }
731 }
732
733 try {
734 Class<?> caller = Reflection.getCallerClass();
735 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
736 } catch (InvocationTargetException e) {
737 Unsafe.getUnsafe().throwException(e.getTargetException());
738 // Not reached
739 return null;
740 }
741 }
742
743 private transient volatile Constructor<T> cachedConstructor;
744
745 /**
746 * Determines if the specified {@code Object} is assignment-compatible
747 * with the object represented by this {@code Class}. This method is
748 * the dynamic equivalent of the Java language {@code instanceof}
749 * operator. The method returns {@code true} if the specified
750 * {@code Object} argument is non-null and can be cast to the
751 * reference type represented by this {@code Class} object without
752 * raising a {@code ClassCastException.} It returns {@code false}
753 * otherwise.
754 *
755 * <p> Specifically, if this {@code Class} object represents a
756 * declared class, this method returns {@code true} if the specified
757 * {@code Object} argument is an instance of the represented class (or
758 * of any of its subclasses); it returns {@code false} otherwise. If
759 * this {@code Class} object represents an array class, this method
760 * returns {@code true} if the specified {@code Object} argument
761 * can be converted to an object of the array class by an identity
762 * conversion or by a widening reference conversion; it returns
763 * {@code false} otherwise. If this {@code Class} object
764 * represents an interface, this method returns {@code true} if the
765 * class or any superclass of the specified {@code Object} argument
766 * implements this interface; it returns {@code false} otherwise. If
767 * this {@code Class} object represents a primitive type, this method
768 * returns {@code false}.
769 *
770 * @param obj the object to check
771 * @return true if {@code obj} is an instance of this class
772 *
773 * @since 1.1
774 */
775 @IntrinsicCandidate
776 public native boolean isInstance(Object obj);
777
778
779 /**
780 * Determines if the class or interface represented by this
781 * {@code Class} object is either the same as, or is a superclass or
782 * superinterface of, the class or interface represented by the specified
783 * {@code Class} parameter. It returns {@code true} if so;
784 * otherwise it returns {@code false}. If this {@code Class}
785 * object represents a primitive type, this method returns
786 * {@code true} if the specified {@code Class} parameter is
787 * exactly this {@code Class} object; otherwise it returns
788 * {@code false}.
789 *
790 * <p> Specifically, this method tests whether the type represented by the
791 * specified {@code Class} parameter can be converted to the type
792 * represented by this {@code Class} object via an identity conversion
793 * or via a widening reference conversion. See <cite>The Java Language
794 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
795 * for details.
796 *
797 * @param cls the {@code Class} object to be checked
798 * @return the {@code boolean} value indicating whether objects of the
799 * type {@code cls} can be assigned to objects of this class
800 * @throws NullPointerException if the specified Class parameter is
801 * null.
802 * @since 1.1
803 */
804 @IntrinsicCandidate
805 public native boolean isAssignableFrom(Class<?> cls);
806
807
808 /**
809 * Determines if this {@code Class} object represents an
810 * interface type.
811 *
812 * @return {@code true} if this {@code Class} object represents an interface;
813 * {@code false} otherwise.
814 */
815 @IntrinsicCandidate
816 public native boolean isInterface();
817
818
819 /**
820 * Determines if this {@code Class} object represents an array class.
821 *
822 * @return {@code true} if this {@code Class} object represents an array class;
823 * {@code false} otherwise.
824 * @since 1.1
825 */
826 @IntrinsicCandidate
827 public native boolean isArray();
828
829
830 /**
831 * Determines if this {@code Class} object represents a primitive
832 * type or void.
833 *
834 * <p> There are nine predefined {@code Class} objects to
835 * represent the eight primitive types and void. These are
836 * created by the Java Virtual Machine, and have the same
837 * {@linkplain #getName() names} as the primitive types that they
838 * represent, namely {@code boolean}, {@code byte}, {@code char},
839 * {@code short}, {@code int}, {@code long}, {@code float}, and
840 * {@code double}.
841 *
842 * <p>No other class objects are considered primitive.
843 *
844 * @apiNote
845 * A {@code Class} object represented by a primitive type can be
846 * accessed via the {@code TYPE} public static final variables
847 * defined in the primitive wrapper classes such as {@link
848 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
849 * language, the objects may be referred to by a class literal
850 * expression such as {@code int.class}. The {@code Class} object
851 * for void can be expressed as {@code void.class} or {@link
852 * java.lang.Void#TYPE Void.TYPE}.
853 *
854 * @return true if and only if this class represents a primitive type
855 *
856 * @see java.lang.Boolean#TYPE
857 * @see java.lang.Character#TYPE
858 * @see java.lang.Byte#TYPE
859 * @see java.lang.Short#TYPE
860 * @see java.lang.Integer#TYPE
861 * @see java.lang.Long#TYPE
862 * @see java.lang.Float#TYPE
863 * @see java.lang.Double#TYPE
864 * @see java.lang.Void#TYPE
865 * @since 1.1
866 * @jls 15.8.2 Class Literals
867 */
868 @IntrinsicCandidate
869 public native boolean isPrimitive();
870
871 /**
872 * Returns true if this {@code Class} object represents an annotation
873 * interface. Note that if this method returns true, {@link #isInterface()}
874 * would also return true, as all annotation interfaces are also interfaces.
875 *
876 * @return {@code true} if this {@code Class} object represents an annotation
877 * interface; {@code false} otherwise
878 * @since 1.5
879 */
880 public boolean isAnnotation() {
881 return (getModifiers() & ANNOTATION) != 0;
882 }
883
884 /**
885 *{@return {@code true} if and only if this class has the synthetic modifier
886 * bit set}
887 *
888 * @jls 13.1 The Form of a Binary
889 * @jvms 4.1 The {@code ClassFile} Structure
890 * @see <a
891 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
892 * programming language and JVM modeling in core reflection</a>
893 * @since 1.5
894 */
895 public boolean isSynthetic() {
896 return (getModifiers() & SYNTHETIC) != 0;
897 }
898
899 /**
900 * Returns the name of the entity (class, interface, array class,
901 * primitive type, or void) represented by this {@code Class} object.
902 *
903 * <p> If this {@code Class} object represents a class or interface,
904 * not an array class, then:
905 * <ul>
906 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
907 * then the {@linkplain ClassLoader##binary-name binary name}
908 * of the class or interface is returned.
909 * <li> If the class or interface is hidden, then the result is a string
910 * of the form: {@code N + '/' + <suffix>}
911 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
912 * indicated by the {@code class} file passed to
913 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
914 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
915 * </ul>
916 *
917 * <p> If this {@code Class} object represents an array class, then
918 * the result is a string consisting of one or more '{@code [}' characters
919 * representing the depth of the array nesting, followed by the element
920 * type as encoded using the following table:
921 *
922 * <blockquote><table class="striped" id="nameFormat">
923 * <caption style="display:none">Element types and encodings</caption>
924 * <thead>
925 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
926 * </thead>
927 * <tbody style="text-align:left">
928 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
929 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
930 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
931 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
932 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
933 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
934 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
935 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
936 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
937 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
938 * </tbody>
939 * </table></blockquote>
940 *
941 * <p> If this {@code Class} object represents a primitive type or {@code void},
942 * then the result is a string with the same spelling as the Java language
943 * keyword which corresponds to the primitive type or {@code void}.
944 *
945 * <p> Examples:
946 * <blockquote><pre>
947 * String.class.getName()
948 * returns "java.lang.String"
949 * Character.UnicodeBlock.class.getName()
950 * returns "java.lang.Character$UnicodeBlock"
951 * byte.class.getName()
952 * returns "byte"
953 * (new Object[3]).getClass().getName()
954 * returns "[Ljava.lang.Object;"
955 * (new int[3][4][5][6][7][8][9]).getClass().getName()
956 * returns "[[[[[[[I"
957 * </pre></blockquote>
958 *
959 * @apiNote
960 * Distinct class objects can have the same name but different class loaders.
961 *
962 * @return the name of the class, interface, or other entity
963 * represented by this {@code Class} object.
964 * @jls 13.1 The Form of a Binary
965 */
966 public String getName() {
967 String name = this.name;
968 return name != null ? name : initClassName();
969 }
970
971 // Cache the name to reduce the number of calls into the VM.
972 // This field would be set by VM itself during initClassName call.
973 private transient String name;
974 private native String initClassName();
975
976 /**
977 * Returns the class loader for the class. Some implementations may use
978 * null to represent the bootstrap class loader. This method will return
979 * null in such implementations if this class was loaded by the bootstrap
980 * class loader.
981 *
982 * <p>If this {@code Class} object
983 * represents a primitive type or void, null is returned.
984 *
985 * @return the class loader that loaded the class or interface
986 * represented by this {@code Class} object.
987 * @see java.lang.ClassLoader
988 */
989 public ClassLoader getClassLoader() {
990 return classLoader;
991 }
992
993 // Package-private to allow ClassLoader access
994 ClassLoader getClassLoader0() { return classLoader; }
995
996 /**
997 * Returns the module that this class or interface is a member of.
998 *
999 * If this class represents an array type then this method returns the
1000 * {@code Module} for the element type. If this class represents a
1001 * primitive type or void, then the {@code Module} object for the
1002 * {@code java.base} module is returned.
1003 *
1004 * If this class is in an unnamed module then the {@linkplain
1005 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1006 * loader for this class is returned.
1007 *
1008 * @return the module that this class or interface is a member of
1009 *
1010 * @since 9
1011 */
1012 public Module getModule() {
1013 return module;
1014 }
1015
1016 // set by VM
1017 @Stable
1018 private transient Module module;
1019
1020 // Initialized in JVM not by private constructor
1021 // This field is filtered from reflection access, i.e. getDeclaredField
1022 // will throw NoSuchFieldException
1023 private final ClassLoader classLoader;
1024
1025 private transient Object classData; // Set by VM
1026 private transient Object[] signers; // Read by VM, mutable
1027
1028 // package-private
1029 Object getClassData() {
1030 return classData;
1031 }
1032
1033 /**
1034 * Returns an array of {@code TypeVariable} objects that represent the
1035 * type variables declared by the generic declaration represented by this
1036 * {@code GenericDeclaration} object, in declaration order. Returns an
1037 * array of length 0 if the underlying generic declaration declares no type
1038 * variables.
1039 *
1040 * @return an array of {@code TypeVariable} objects that represent
1041 * the type variables declared by this generic declaration
1042 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1043 * signature of this generic declaration does not conform to
1044 * the format specified in section {@jvms 4.7.9} of
1045 * <cite>The Java Virtual Machine Specification</cite>
1046 * @since 1.5
1047 */
1048 @SuppressWarnings("unchecked")
1049 public TypeVariable<Class<T>>[] getTypeParameters() {
1050 ClassRepository info = getGenericInfo();
1051 if (info != null)
1052 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1053 else
1054 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1055 }
1056
1057
1058 /**
1059 * Returns the {@code Class} representing the direct superclass of the
1060 * entity (class, interface, primitive type or void) represented by
1061 * this {@code Class}. If this {@code Class} represents either the
1062 * {@code Object} class, an interface, a primitive type, or void, then
1063 * null is returned. If this {@code Class} object represents an array class
1064 * then the {@code Class} object representing the {@code Object} class is
1065 * returned.
1066 *
1067 * @return the direct superclass of the class represented by this {@code Class} object
1068 */
1069 @IntrinsicCandidate
1070 public native Class<? super T> getSuperclass();
1071
1072
1073 /**
1074 * Returns the {@code Type} representing the direct superclass of
1075 * the entity (class, interface, primitive type or void) represented by
1076 * this {@code Class} object.
1077 *
1078 * <p>If the superclass is a parameterized type, the {@code Type}
1079 * object returned must accurately reflect the actual type
1080 * arguments used in the source code. The parameterized type
1081 * representing the superclass is created if it had not been
1082 * created before. See the declaration of {@link
1083 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1084 * semantics of the creation process for parameterized types. If
1085 * this {@code Class} object represents either the {@code Object}
1086 * class, an interface, a primitive type, or void, then null is
1087 * 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 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1092 * class signature does not conform to the format specified in
1093 * section {@jvms 4.7.9} of <cite>The Java Virtual
1094 * Machine Specification</cite>
1095 * @throws TypeNotPresentException if the generic superclass
1096 * refers to a non-existent type declaration
1097 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1098 * generic superclass refers to a parameterized type that cannot be
1099 * instantiated for any reason
1100 * @return the direct superclass of the class represented by this {@code Class} object
1101 * @since 1.5
1102 */
1103 public Type getGenericSuperclass() {
1104 ClassRepository info = getGenericInfo();
1105 if (info == null) {
1106 return getSuperclass();
1107 }
1108
1109 // Historical irregularity:
1110 // Generic signature marks interfaces with superclass = Object
1111 // but this API returns null for interfaces
1112 if (isInterface()) {
1113 return null;
1114 }
1115
1116 return info.getSuperclass();
1117 }
1118
1119 /**
1120 * Gets the package of this class.
1121 *
1122 * <p>If this class represents an array type, a primitive type or void,
1123 * this method returns {@code null}.
1124 *
1125 * @return the package of this class.
1126 */
1127 public Package getPackage() {
1128 if (isPrimitive() || isArray()) {
1129 return null;
1130 }
1131 ClassLoader cl = classLoader;
1132 return cl != null ? cl.definePackage(this)
1133 : BootLoader.definePackage(this);
1134 }
1135
1136 /**
1137 * Returns the fully qualified package name.
1138 *
1139 * <p> If this class is a top level class, then this method returns the fully
1140 * qualified name of the package that the class is a member of, or the
1141 * empty string if the class is in an unnamed package.
1142 *
1143 * <p> If this class is a member class, then this method is equivalent to
1144 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1145 * enclosing class}.
1146 *
1147 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1148 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1149 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1150 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1151 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1152 *
1153 * <p> If this class represents an array type then this method returns the
1154 * package name of the element type. If this class represents a primitive
1155 * type or void then the package name "{@code java.lang}" is returned.
1156 *
1157 * @return the fully qualified package name
1158 *
1159 * @since 9
1160 * @jls 6.7 Fully Qualified Names and Canonical Names
1161 */
1162 public String getPackageName() {
1163 String pn = this.packageName;
1164 if (pn == null) {
1165 Class<?> c = isArray() ? elementType() : this;
1166 if (c.isPrimitive()) {
1167 pn = "java.lang";
1168 } else {
1169 String cn = c.getName();
1170 int dot = cn.lastIndexOf('.');
1171 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1172 }
1173 this.packageName = pn;
1174 }
1175 return pn;
1176 }
1177
1178 // cached package name
1179 private transient String packageName;
1180
1181 /**
1182 * Returns the interfaces directly implemented by the class or interface
1183 * represented by this {@code Class} object.
1184 *
1185 * <p>If this {@code Class} object represents a class, the return value is an array
1186 * containing objects representing all interfaces directly implemented by
1187 * the class. The order of the interface objects in the array corresponds
1188 * to the order of the interface names in the {@code implements} clause of
1189 * the declaration of the class represented by this {@code Class} object. For example,
1190 * given the declaration:
1191 * <blockquote>
1192 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1193 * </blockquote>
1194 * suppose the value of {@code s} is an instance of
1195 * {@code Shimmer}; the value of the expression:
1196 * <blockquote>
1197 * {@code s.getClass().getInterfaces()[0]}
1198 * </blockquote>
1199 * is the {@code Class} object that represents interface
1200 * {@code FloorWax}; and the value of:
1201 * <blockquote>
1202 * {@code s.getClass().getInterfaces()[1]}
1203 * </blockquote>
1204 * is the {@code Class} object that represents interface
1205 * {@code DessertTopping}.
1206 *
1207 * <p>If this {@code Class} object represents an interface, the array contains objects
1208 * representing all interfaces directly extended by the interface. The
1209 * order of the interface objects in the array corresponds to the order of
1210 * the interface names in the {@code extends} clause of the declaration of
1211 * the interface represented by this {@code Class} object.
1212 *
1213 * <p>If this {@code Class} object represents a class or interface that implements no
1214 * interfaces, the method returns an array of length 0.
1215 *
1216 * <p>If this {@code Class} object represents a primitive type or void, the method
1217 * returns an array of length 0.
1218 *
1219 * <p>If this {@code Class} object represents an array type, the
1220 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1221 * returned in that order.
1222 *
1223 * @return an array of interfaces directly implemented by this class
1224 */
1225 public Class<?>[] getInterfaces() {
1226 // defensively copy before handing over to user code
1227 return getInterfaces(true);
1228 }
1229
1230 private Class<?>[] getInterfaces(boolean cloneArray) {
1231 ReflectionData<T> rd = reflectionData();
1232 if (rd == null) {
1233 // no cloning required
1234 return getInterfaces0();
1235 } else {
1236 Class<?>[] interfaces = rd.interfaces;
1237 if (interfaces == null) {
1238 interfaces = getInterfaces0();
1239 rd.interfaces = interfaces;
1240 }
1241 // defensively copy if requested
1242 return cloneArray ? interfaces.clone() : interfaces;
1243 }
1244 }
1245
1246 private native Class<?>[] getInterfaces0();
1247
1248 /**
1249 * Returns the {@code Type}s representing the interfaces
1250 * directly implemented by the class or interface represented by
1251 * this {@code Class} object.
1252 *
1253 * <p>If a superinterface is a parameterized type, the
1254 * {@code Type} object returned for it must accurately reflect
1255 * the actual type arguments used in the source code. The
1256 * parameterized type representing each superinterface is created
1257 * if it had not been created before. See the declaration of
1258 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1259 * for the semantics of the creation process for parameterized
1260 * types.
1261 *
1262 * <p>If this {@code Class} object represents a class, the return value is an array
1263 * containing objects representing all interfaces directly implemented by
1264 * the class. The order of the interface objects in the array corresponds
1265 * to the order of the interface names in the {@code implements} clause of
1266 * the declaration of the class represented by this {@code Class} object.
1267 *
1268 * <p>If this {@code Class} object represents an interface, the array contains objects
1269 * representing all interfaces directly extended by the interface. The
1270 * order of the interface objects in the array corresponds to the order of
1271 * the interface names in the {@code extends} clause of the declaration of
1272 * the interface represented by this {@code Class} object.
1273 *
1274 * <p>If this {@code Class} object represents a class or interface that implements no
1275 * interfaces, the method returns an array of length 0.
1276 *
1277 * <p>If this {@code Class} object represents a primitive type or void, the method
1278 * returns an array of length 0.
1279 *
1280 * <p>If this {@code Class} object represents an array type, the
1281 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1282 * returned in that order.
1283 *
1284 * @throws java.lang.reflect.GenericSignatureFormatError
1285 * if the generic class signature does not conform to the
1286 * format specified in section {@jvms 4.7.9} of <cite>The
1287 * Java Virtual Machine Specification</cite>
1288 * @throws TypeNotPresentException if any of the generic
1289 * superinterfaces refers to a non-existent type declaration
1290 * @throws java.lang.reflect.MalformedParameterizedTypeException
1291 * if any of the generic superinterfaces refer to a parameterized
1292 * type that cannot be instantiated for any reason
1293 * @return an array of interfaces directly implemented by this class
1294 * @since 1.5
1295 */
1296 public Type[] getGenericInterfaces() {
1297 ClassRepository info = getGenericInfo();
1298 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1299 }
1300
1301
1302 /**
1303 * Returns the {@code Class} representing the component type of an
1304 * array. If this class does not represent an array class this method
1305 * returns null.
1306 *
1307 * @return the {@code Class} representing the component type of this
1308 * class if this class is an array
1309 * @see java.lang.reflect.Array
1310 * @since 1.1
1311 */
1312 public Class<?> getComponentType() {
1313 // Only return for array types. Storage may be reused for Class for instance types.
1314 if (isArray()) {
1315 return componentType;
1316 } else {
1317 return null;
1318 }
1319 }
1320
1321 private final Class<?> componentType;
1322
1323 /*
1324 * Returns the {@code Class} representing the element type of an array class.
1325 * If this class does not represent an array class, then this method returns
1326 * {@code null}.
1327 */
1328 private Class<?> elementType() {
1329 if (!isArray()) return null;
1330
1331 Class<?> c = this;
1332 while (c.isArray()) {
1333 c = c.getComponentType();
1334 }
1335 return c;
1336 }
1337
1338 /**
1339 * Returns the Java language modifiers for this class or interface, encoded
1340 * in an integer. The modifiers consist of the Java Virtual Machine's
1341 * constants for {@code public}, {@code protected},
1342 * {@code private}, {@code final}, {@code static},
1343 * {@code abstract} and {@code interface}; they should be decoded
1344 * using the methods of class {@code Modifier}.
1345 *
1346 * <p> If the underlying class is an array class:
1347 * <ul>
1348 * <li> its {@code public}, {@code private} and {@code protected}
1349 * modifiers are the same as those of its component type
1350 * <li> its {@code abstract} and {@code final} modifiers are always
1351 * {@code true}
1352 * <li> its interface modifier is always {@code false}, even when
1353 * the component type is an interface
1354 * </ul>
1355 * If this {@code Class} object represents a primitive type or
1356 * void, its {@code public}, {@code abstract}, and {@code final}
1357 * modifiers are always {@code true}.
1358 * For {@code Class} objects representing void, primitive types, and
1359 * arrays, the values of other modifiers are {@code false} other
1360 * than as specified above.
1361 *
1362 * <p> The modifier encodings are defined in section {@jvms 4.1}
1363 * of <cite>The Java Virtual Machine Specification</cite>.
1364 *
1365 * @return the {@code int} representing the modifiers for this class
1366 * @see java.lang.reflect.Modifier
1367 * @see #accessFlags()
1368 * @see <a
1369 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1370 * programming language and JVM modeling in core reflection</a>
1371 * @since 1.1
1372 * @jls 8.1.1 Class Modifiers
1373 * @jls 9.1.1 Interface Modifiers
1374 * @jvms 4.1 The {@code ClassFile} Structure
1375 */
1376 @IntrinsicCandidate
1377 public native int getModifiers();
1378
1379 /**
1380 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1381 * flags} for this class, possibly empty}
1382 *
1383 * <p> If the underlying class is an array class:
1384 * <ul>
1385 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1386 * access flags are the same as those of its component type
1387 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1388 * <li> its {@code INTERFACE} flag is absent, even when the
1389 * component type is an interface
1390 * </ul>
1391 * If this {@code Class} object represents a primitive type or
1392 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1393 * {@code FINAL}.
1394 * For {@code Class} objects representing void, primitive types, and
1395 * arrays, access flags are absent other than as specified above.
1396 *
1397 * @see #getModifiers()
1398 * @jvms 4.1 The ClassFile Structure
1399 * @jvms 4.7.6 The InnerClasses Attribute
1400 * @since 20
1401 */
1402 public Set<AccessFlag> accessFlags() {
1403 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1404 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1405 // and STATIC, which are not allowed on Location.CLASS.
1406 // Use getClassAccessFlagsRaw to expose SUPER status.
1407 var location = (isMemberClass() || isLocalClass() ||
1408 isAnonymousClass() || isArray()) ?
1409 AccessFlag.Location.INNER_CLASS :
1410 AccessFlag.Location.CLASS;
1411 return AccessFlag.maskToAccessFlags((location == AccessFlag.Location.CLASS) ?
1412 getClassAccessFlagsRaw() :
1413 getModifiers(),
1414 location);
1415 }
1416
1417 /**
1418 * Gets the signers of this class.
1419 *
1420 * @return the signers of this class, or null if there are no signers. In
1421 * particular, this method returns null if this {@code Class} object represents
1422 * a primitive type or void.
1423 * @since 1.1
1424 */
1425 public Object[] getSigners() {
1426 var signers = this.signers;
1427 return signers == null ? null : signers.clone();
1428 }
1429
1430 /**
1431 * Set the signers of this class.
1432 */
1433 void setSigners(Object[] signers) {
1434 if (!isPrimitive() && !isArray()) {
1435 this.signers = signers;
1436 }
1437 }
1438
1439 /**
1440 * If this {@code Class} object represents a local or anonymous
1441 * class within a method, returns a {@link
1442 * java.lang.reflect.Method Method} object representing the
1443 * immediately enclosing method of the underlying class. Returns
1444 * {@code null} otherwise.
1445 *
1446 * In particular, this method returns {@code null} if the underlying
1447 * class is a local or anonymous class immediately enclosed by a class or
1448 * interface declaration, instance initializer or static initializer.
1449 *
1450 * @return the immediately enclosing method of the underlying class, if
1451 * that class is a local or anonymous class; otherwise {@code null}.
1452 *
1453 * @since 1.5
1454 */
1455 public Method getEnclosingMethod() {
1456 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1457
1458 if (enclosingInfo == null)
1459 return null;
1460 else {
1461 if (!enclosingInfo.isMethod())
1462 return null;
1463
1464 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1465 getFactory());
1466 Class<?> returnType = toClass(typeInfo.getReturnType());
1467 Type [] parameterTypes = typeInfo.getParameterTypes();
1468 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1469
1470 // Convert Types to Classes; returned types *should*
1471 // be class objects since the methodDescriptor's used
1472 // don't have generics information
1473 for(int i = 0; i < parameterClasses.length; i++)
1474 parameterClasses[i] = toClass(parameterTypes[i]);
1475
1476 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1477 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1478
1479 /*
1480 * Loop over all declared methods; match method name,
1481 * number of and type of parameters, *and* return
1482 * type. Matching return type is also necessary
1483 * because of covariant returns, etc.
1484 */
1485 ReflectionFactory fact = getReflectionFactory();
1486 for (Method m : candidates) {
1487 if (m.getName().equals(enclosingInfo.getName()) &&
1488 arrayContentsEq(parameterClasses,
1489 fact.getExecutableSharedParameterTypes(m))) {
1490 // finally, check return type
1491 if (m.getReturnType().equals(returnType)) {
1492 return fact.copyMethod(m);
1493 }
1494 }
1495 }
1496
1497 throw new InternalError("Enclosing method not found");
1498 }
1499 }
1500
1501 private native Object[] getEnclosingMethod0();
1502
1503 private EnclosingMethodInfo getEnclosingMethodInfo() {
1504 Object[] enclosingInfo = getEnclosingMethod0();
1505 if (enclosingInfo == null)
1506 return null;
1507 else {
1508 return new EnclosingMethodInfo(enclosingInfo);
1509 }
1510 }
1511
1512 private static final class EnclosingMethodInfo {
1513 private final Class<?> enclosingClass;
1514 private final String name;
1515 private final String descriptor;
1516
1517 static void validate(Object[] enclosingInfo) {
1518 if (enclosingInfo.length != 3)
1519 throw new InternalError("Malformed enclosing method information");
1520 try {
1521 // The array is expected to have three elements:
1522
1523 // the immediately enclosing class
1524 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1525 assert(enclosingClass != null);
1526
1527 // the immediately enclosing method or constructor's
1528 // name (can be null).
1529 String name = (String)enclosingInfo[1];
1530
1531 // the immediately enclosing method or constructor's
1532 // descriptor (null iff name is).
1533 String descriptor = (String)enclosingInfo[2];
1534 assert((name != null && descriptor != null) || name == descriptor);
1535 } catch (ClassCastException cce) {
1536 throw new InternalError("Invalid type in enclosing method information", cce);
1537 }
1538 }
1539
1540 EnclosingMethodInfo(Object[] enclosingInfo) {
1541 validate(enclosingInfo);
1542 this.enclosingClass = (Class<?>)enclosingInfo[0];
1543 this.name = (String)enclosingInfo[1];
1544 this.descriptor = (String)enclosingInfo[2];
1545 }
1546
1547 boolean isPartial() {
1548 return enclosingClass == null || name == null || descriptor == null;
1549 }
1550
1551 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1552
1553 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1554
1555 Class<?> getEnclosingClass() { return enclosingClass; }
1556
1557 String getName() { return name; }
1558
1559 String getDescriptor() { return descriptor; }
1560
1561 }
1562
1563 private static Class<?> toClass(Type o) {
1564 if (o instanceof GenericArrayType gat)
1565 return toClass(gat.getGenericComponentType()).arrayType();
1566 return (Class<?>)o;
1567 }
1568
1569 /**
1570 * If this {@code Class} object represents a local or anonymous
1571 * class within a constructor, returns a {@link
1572 * java.lang.reflect.Constructor Constructor} object representing
1573 * the immediately enclosing constructor of the underlying
1574 * class. Returns {@code null} otherwise. In particular, this
1575 * method returns {@code null} if the underlying class is a local
1576 * or anonymous class immediately enclosed by a class or
1577 * interface declaration, instance initializer or static initializer.
1578 *
1579 * @return the immediately enclosing constructor of the underlying class, if
1580 * that class is a local or anonymous class; otherwise {@code null}.
1581 *
1582 * @since 1.5
1583 */
1584 public Constructor<?> getEnclosingConstructor() {
1585 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1586
1587 if (enclosingInfo == null)
1588 return null;
1589 else {
1590 if (!enclosingInfo.isConstructor())
1591 return null;
1592
1593 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1594 getFactory());
1595 Type [] parameterTypes = typeInfo.getParameterTypes();
1596 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1597
1598 // Convert Types to Classes; returned types *should*
1599 // be class objects since the methodDescriptor's used
1600 // don't have generics information
1601 for (int i = 0; i < parameterClasses.length; i++)
1602 parameterClasses[i] = toClass(parameterTypes[i]);
1603
1604
1605 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1606 Constructor<?>[] candidates = enclosingCandidate
1607 .privateGetDeclaredConstructors(false);
1608 /*
1609 * Loop over all declared constructors; match number
1610 * of and type of parameters.
1611 */
1612 ReflectionFactory fact = getReflectionFactory();
1613 for (Constructor<?> c : candidates) {
1614 if (arrayContentsEq(parameterClasses,
1615 fact.getExecutableSharedParameterTypes(c))) {
1616 return fact.copyConstructor(c);
1617 }
1618 }
1619
1620 throw new InternalError("Enclosing constructor not found");
1621 }
1622 }
1623
1624
1625 /**
1626 * If the class or interface represented by this {@code Class} object
1627 * is a member of another class, returns the {@code Class} object
1628 * representing the class in which it was declared. This method returns
1629 * null if this class or interface is not a member of any other class. If
1630 * this {@code Class} object represents an array class, a primitive
1631 * type, or void, then this method returns null.
1632 *
1633 * @return the declaring class for this class
1634 * @since 1.1
1635 */
1636 public Class<?> getDeclaringClass() {
1637 return getDeclaringClass0();
1638 }
1639
1640 private native Class<?> getDeclaringClass0();
1641
1642
1643 /**
1644 * Returns the immediately enclosing class of the underlying
1645 * class. If the underlying class is a top level class this
1646 * method returns {@code null}.
1647 * @return the immediately enclosing class of the underlying class
1648 * @since 1.5
1649 */
1650 public Class<?> getEnclosingClass() {
1651 // There are five kinds of classes (or interfaces):
1652 // a) Top level classes
1653 // b) Nested classes (static member classes)
1654 // c) Inner classes (non-static member classes)
1655 // d) Local classes (named classes declared within a method)
1656 // e) Anonymous classes
1657
1658
1659 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1660 // attribute if and only if it is a local class or an
1661 // anonymous class.
1662 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1663 Class<?> enclosingCandidate;
1664
1665 if (enclosingInfo == null) {
1666 // This is a top level or a nested class or an inner class (a, b, or c)
1667 enclosingCandidate = getDeclaringClass0();
1668 } else {
1669 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1670 // This is a local class or an anonymous class (d or e)
1671 if (enclosingClass == this || enclosingClass == null)
1672 throw new InternalError("Malformed enclosing method information");
1673 else
1674 enclosingCandidate = enclosingClass;
1675 }
1676 return enclosingCandidate;
1677 }
1678
1679 /**
1680 * Returns the simple name of the underlying class as given in the
1681 * source code. An empty string is returned if the underlying class is
1682 * {@linkplain #isAnonymousClass() anonymous}.
1683 * A {@linkplain #isSynthetic() synthetic class}, one not present
1684 * in source code, can have a non-empty name including special
1685 * characters, such as "{@code $}".
1686 *
1687 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1688 * component type with "[]" appended. In particular the simple
1689 * name of an array class whose component type is anonymous is "[]".
1690 *
1691 * @return the simple name of the underlying class
1692 * @since 1.5
1693 */
1694 public String getSimpleName() {
1695 ReflectionData<T> rd = reflectionData();
1696 String simpleName = rd.simpleName;
1697 if (simpleName == null) {
1698 rd.simpleName = simpleName = getSimpleName0();
1699 }
1700 return simpleName;
1701 }
1702
1703 private String getSimpleName0() {
1704 if (isArray()) {
1705 return getComponentType().getSimpleName().concat("[]");
1706 }
1707 String simpleName = getSimpleBinaryName();
1708 if (simpleName == null) { // top level class
1709 simpleName = getName();
1710 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1711 }
1712 return simpleName;
1713 }
1714
1715 /**
1716 * Return an informative string for the name of this class or interface.
1717 *
1718 * @return an informative string for the name of this class or interface
1719 * @since 1.8
1720 */
1721 public String getTypeName() {
1722 if (isArray()) {
1723 try {
1724 Class<?> cl = this;
1725 int dimensions = 0;
1726 do {
1727 dimensions++;
1728 cl = cl.getComponentType();
1729 } while (cl.isArray());
1730 return cl.getName().concat("[]".repeat(dimensions));
1731 } catch (Throwable e) { /*FALLTHRU*/ }
1732 }
1733 return getName();
1734 }
1735
1736 /**
1737 * Returns the canonical name of the underlying class as
1738 * defined by <cite>The Java Language Specification</cite>.
1739 * Returns {@code null} if the underlying class does not have a canonical
1740 * name. Classes without canonical names include:
1741 * <ul>
1742 * <li>a {@linkplain #isLocalClass() local class}
1743 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1744 * <li>a {@linkplain #isHidden() hidden class}
1745 * <li>an array whose component type does not have a canonical name</li>
1746 * </ul>
1747 *
1748 * The canonical name for a primitive class is the keyword for the
1749 * corresponding primitive type ({@code byte}, {@code short},
1750 * {@code char}, {@code int}, and so on).
1751 *
1752 * <p>An array type has a canonical name if and only if its
1753 * component type has a canonical name. When an array type has a
1754 * canonical name, it is equal to the canonical name of the
1755 * component type followed by "{@code []}".
1756 *
1757 * @return the canonical name of the underlying class if it exists, and
1758 * {@code null} otherwise.
1759 * @jls 6.7 Fully Qualified Names and Canonical Names
1760 * @since 1.5
1761 */
1762 public String getCanonicalName() {
1763 ReflectionData<T> rd = reflectionData();
1764 String canonicalName = rd.canonicalName;
1765 if (canonicalName == null) {
1766 rd.canonicalName = canonicalName = getCanonicalName0();
1767 }
1768 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1769 }
1770
1771 private String getCanonicalName0() {
1772 if (isArray()) {
1773 String canonicalName = getComponentType().getCanonicalName();
1774 if (canonicalName != null)
1775 return canonicalName.concat("[]");
1776 else
1777 return ReflectionData.NULL_SENTINEL;
1778 }
1779 if (isHidden() || isLocalOrAnonymousClass())
1780 return ReflectionData.NULL_SENTINEL;
1781 Class<?> enclosingClass = getEnclosingClass();
1782 if (enclosingClass == null) { // top level class
1783 return getName();
1784 } else {
1785 String enclosingName = enclosingClass.getCanonicalName();
1786 if (enclosingName == null)
1787 return ReflectionData.NULL_SENTINEL;
1788 String simpleName = getSimpleName();
1789 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1790 .append(enclosingName)
1791 .append('.')
1792 .append(simpleName)
1793 .toString();
1794 }
1795 }
1796
1797 /**
1798 * Returns {@code true} if and only if the underlying class
1799 * is an anonymous class.
1800 *
1801 * @apiNote
1802 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1803 *
1804 * @return {@code true} if and only if this class is an anonymous class.
1805 * @since 1.5
1806 * @jls 15.9.5 Anonymous Class Declarations
1807 */
1808 public boolean isAnonymousClass() {
1809 return !isArray() && isLocalOrAnonymousClass() &&
1810 getSimpleBinaryName0() == null;
1811 }
1812
1813 /**
1814 * Returns {@code true} if and only if the underlying class
1815 * is a local class.
1816 *
1817 * @return {@code true} if and only if this class is a local class.
1818 * @since 1.5
1819 * @jls 14.3 Local Class and Interface Declarations
1820 */
1821 public boolean isLocalClass() {
1822 return isLocalOrAnonymousClass() &&
1823 (isArray() || getSimpleBinaryName0() != null);
1824 }
1825
1826 /**
1827 * Returns {@code true} if and only if the underlying class
1828 * is a member class.
1829 *
1830 * @return {@code true} if and only if this class is a member class.
1831 * @since 1.5
1832 * @jls 8.5 Member Class and Interface Declarations
1833 */
1834 public boolean isMemberClass() {
1835 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1836 }
1837
1838 /**
1839 * Returns the "simple binary name" of the underlying class, i.e.,
1840 * the binary name without the leading enclosing class name.
1841 * Returns {@code null} if the underlying class is a top level
1842 * class.
1843 */
1844 private String getSimpleBinaryName() {
1845 if (isTopLevelClass())
1846 return null;
1847 String name = getSimpleBinaryName0();
1848 if (name == null) // anonymous class
1849 return "";
1850 return name;
1851 }
1852
1853 private native String getSimpleBinaryName0();
1854
1855 /**
1856 * Returns {@code true} if this is a top level class. Returns {@code false}
1857 * otherwise.
1858 */
1859 private boolean isTopLevelClass() {
1860 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1861 }
1862
1863 /**
1864 * Returns {@code true} if this is a local class or an anonymous
1865 * class. Returns {@code false} otherwise.
1866 */
1867 private boolean isLocalOrAnonymousClass() {
1868 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1869 // attribute if and only if it is a local class or an
1870 // anonymous class.
1871 return hasEnclosingMethodInfo();
1872 }
1873
1874 private boolean hasEnclosingMethodInfo() {
1875 Object[] enclosingInfo = getEnclosingMethod0();
1876 if (enclosingInfo != null) {
1877 EnclosingMethodInfo.validate(enclosingInfo);
1878 return true;
1879 }
1880 return false;
1881 }
1882
1883 /**
1884 * Returns an array containing {@code Class} objects representing all
1885 * the public classes and interfaces that are members of the class
1886 * represented by this {@code Class} object. This includes public
1887 * class and interface members inherited from superclasses and public class
1888 * and interface members declared by the class. This method returns an
1889 * array of length 0 if this {@code Class} object has no public member
1890 * classes or interfaces. This method also returns an array of length 0 if
1891 * this {@code Class} object represents a primitive type, an array
1892 * class, or void.
1893 *
1894 * @return the array of {@code Class} objects representing the public
1895 * members of this class
1896 * @since 1.1
1897 */
1898 public Class<?>[] getClasses() {
1899 List<Class<?>> list = new ArrayList<>();
1900 Class<?> currentClass = Class.this;
1901 while (currentClass != null) {
1902 for (Class<?> m : currentClass.getDeclaredClasses()) {
1903 if (Modifier.isPublic(m.getModifiers())) {
1904 list.add(m);
1905 }
1906 }
1907 currentClass = currentClass.getSuperclass();
1908 }
1909 return list.toArray(new Class<?>[0]);
1910 }
1911
1912
1913 /**
1914 * Returns an array containing {@code Field} objects reflecting all
1915 * the accessible public fields of the class or interface represented by
1916 * this {@code Class} object.
1917 *
1918 * <p> If this {@code Class} object represents a class or interface with
1919 * no accessible public fields, then this method returns an array of length
1920 * 0.
1921 *
1922 * <p> If this {@code Class} object represents a class, then this method
1923 * returns the public fields of the class and of all its superclasses and
1924 * superinterfaces.
1925 *
1926 * <p> If this {@code Class} object represents an interface, then this
1927 * method returns the fields of the interface and of all its
1928 * superinterfaces.
1929 *
1930 * <p> If this {@code Class} object represents an array type, a primitive
1931 * type, or void, then this method returns an array of length 0.
1932 *
1933 * <p> The elements in the returned array are not sorted and are not in any
1934 * particular order.
1935 *
1936 * @return the array of {@code Field} objects representing the
1937 * public fields
1938 *
1939 * @since 1.1
1940 * @jls 8.2 Class Members
1941 * @jls 8.3 Field Declarations
1942 */
1943 public Field[] getFields() {
1944 return copyFields(privateGetPublicFields());
1945 }
1946
1947
1948 /**
1949 * Returns an array containing {@code Method} objects reflecting all the
1950 * public methods of the class or interface represented by this {@code
1951 * Class} object, including those declared by the class or interface and
1952 * those inherited from superclasses and superinterfaces.
1953 *
1954 * <p> If this {@code Class} object represents an array type, then the
1955 * returned array has a {@code Method} object for each of the public
1956 * methods inherited by the array type from {@code Object}. It does not
1957 * contain a {@code Method} object for {@code clone()}.
1958 *
1959 * <p> If this {@code Class} object represents an interface then the
1960 * returned array does not contain any implicitly declared methods from
1961 * {@code Object}. Therefore, if no methods are explicitly declared in
1962 * this interface or any of its superinterfaces then the returned array
1963 * has length 0. (Note that a {@code Class} object which represents a class
1964 * always has public methods, inherited from {@code Object}.)
1965 *
1966 * <p> The returned array never contains methods with names {@value
1967 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1968 *
1969 * <p> The elements in the returned array are not sorted and are not in any
1970 * particular order.
1971 *
1972 * <p> Generally, the result is computed as with the following 4 step algorithm.
1973 * Let C be the class or interface represented by this {@code Class} object:
1974 * <ol>
1975 * <li> A union of methods is composed of:
1976 * <ol type="a">
1977 * <li> C's declared public instance and static methods as returned by
1978 * {@link #getDeclaredMethods()} and filtered to include only public
1979 * methods.</li>
1980 * <li> If C is a class other than {@code Object}, then include the result
1981 * of invoking this algorithm recursively on the superclass of C.</li>
1982 * <li> Include the results of invoking this algorithm recursively on all
1983 * direct superinterfaces of C, but include only instance methods.</li>
1984 * </ol></li>
1985 * <li> Union from step 1 is partitioned into subsets of methods with same
1986 * signature (name, parameter types) and return type.</li>
1987 * <li> Within each such subset only the most specific methods are selected.
1988 * Let method M be a method from a set of methods with same signature
1989 * and return type. M is most specific if there is no such method
1990 * N != M from the same set, such that N is more specific than M.
1991 * N is more specific than M if:
1992 * <ol type="a">
1993 * <li> N is declared by a class and M is declared by an interface; or</li>
1994 * <li> N and M are both declared by classes or both by interfaces and
1995 * N's declaring type is the same as or a subtype of M's declaring type
1996 * (clearly, if M's and N's declaring types are the same type, then
1997 * M and N are the same method).</li>
1998 * </ol></li>
1999 * <li> The result of this algorithm is the union of all selected methods from
2000 * step 3.</li>
2001 * </ol>
2002 *
2003 * @apiNote There may be more than one method with a particular name
2004 * and parameter types in a class because while the Java language forbids a
2005 * class to declare multiple methods with the same signature but different
2006 * return types, the Java virtual machine does not. This
2007 * increased flexibility in the virtual machine can be used to
2008 * implement various language features. For example, covariant
2009 * returns can be implemented with {@linkplain
2010 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2011 * method and the overriding method would have the same
2012 * signature but different return types.
2013 *
2014 * @return the array of {@code Method} objects representing the
2015 * public methods of this class
2016 *
2017 * @jls 8.2 Class Members
2018 * @jls 8.4 Method Declarations
2019 * @since 1.1
2020 */
2021 public Method[] getMethods() {
2022 return copyMethods(privateGetPublicMethods());
2023 }
2024
2025
2026 /**
2027 * Returns an array containing {@code Constructor} objects reflecting
2028 * all the public constructors of the class represented by this
2029 * {@code Class} object. An array of length 0 is returned if the
2030 * class has no public constructors, or if the class is an array class, or
2031 * if the class reflects a primitive type or void.
2032 *
2033 * @apiNote
2034 * While this method returns an array of {@code
2035 * Constructor<T>} objects (that is an array of constructors from
2036 * this class), the return type of this method is {@code
2037 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2038 * might be expected. This less informative return type is
2039 * necessary since after being returned from this method, the
2040 * array could be modified to hold {@code Constructor} objects for
2041 * different classes, which would violate the type guarantees of
2042 * {@code Constructor<T>[]}.
2043 *
2044 * @return the array of {@code Constructor} objects representing the
2045 * public constructors of this class
2046 *
2047 * @see #getDeclaredConstructors()
2048 * @since 1.1
2049 */
2050 public Constructor<?>[] getConstructors() {
2051 return copyConstructors(privateGetDeclaredConstructors(true));
2052 }
2053
2054
2055 /**
2056 * Returns a {@code Field} object that reflects the specified public member
2057 * field of the class or interface represented by this {@code Class}
2058 * object. The {@code name} parameter is a {@code String} specifying the
2059 * simple name of the desired field.
2060 *
2061 * <p> The field to be reflected is determined by the algorithm that
2062 * follows. Let C be the class or interface represented by this {@code Class} object:
2063 *
2064 * <OL>
2065 * <LI> If C declares a public field with the name specified, that is the
2066 * field to be reflected.</LI>
2067 * <LI> If no field was found in step 1 above, this algorithm is applied
2068 * recursively to each direct superinterface of C. The direct
2069 * superinterfaces are searched in the order they were declared.</LI>
2070 * <LI> If no field was found in steps 1 and 2 above, and C has a
2071 * superclass S, then this algorithm is invoked recursively upon S.
2072 * If C has no superclass, then a {@code NoSuchFieldException}
2073 * is thrown.</LI>
2074 * </OL>
2075 *
2076 * <p> If this {@code Class} object represents an array type, then this
2077 * method does not find the {@code length} field of the array type.
2078 *
2079 * @param name the field name
2080 * @return the {@code Field} object of this class specified by
2081 * {@code name}
2082 * @throws NoSuchFieldException if a field with the specified name is
2083 * not found.
2084 * @throws NullPointerException if {@code name} is {@code null}
2085 *
2086 * @since 1.1
2087 * @jls 8.2 Class Members
2088 * @jls 8.3 Field Declarations
2089 */
2090 public Field getField(String name) throws NoSuchFieldException {
2091 Objects.requireNonNull(name);
2092 Field field = getField0(name);
2093 if (field == null) {
2094 throw new NoSuchFieldException(name);
2095 }
2096 return getReflectionFactory().copyField(field);
2097 }
2098
2099
2100 /**
2101 * Returns a {@code Method} object that reflects the specified public
2102 * member method of the class or interface represented by this
2103 * {@code Class} object. The {@code name} parameter is a
2104 * {@code String} specifying the simple name of the desired method. The
2105 * {@code parameterTypes} parameter is an array of {@code Class}
2106 * objects that identify the method's formal parameter types, in declared
2107 * order. If {@code parameterTypes} is {@code null}, it is
2108 * treated as if it were an empty array.
2109 *
2110 * <p> If this {@code Class} object represents an array type, then this
2111 * method finds any public method inherited by the array type from
2112 * {@code Object} except method {@code clone()}.
2113 *
2114 * <p> If this {@code Class} object represents an interface then this
2115 * method does not find any implicitly declared method from
2116 * {@code Object}. Therefore, if no methods are explicitly declared in
2117 * this interface or any of its superinterfaces, then this method does not
2118 * find any method.
2119 *
2120 * <p> This method does not find any method with name {@value
2121 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2122 *
2123 * <p> Generally, the method to be reflected is determined by the 4 step
2124 * algorithm that follows.
2125 * Let C be the class or interface represented by this {@code Class} object:
2126 * <ol>
2127 * <li> A union of methods is composed of:
2128 * <ol type="a">
2129 * <li> C's declared public instance and static methods as returned by
2130 * {@link #getDeclaredMethods()} and filtered to include only public
2131 * methods that match given {@code name} and {@code parameterTypes}</li>
2132 * <li> If C is a class other than {@code Object}, then include the result
2133 * of invoking this algorithm recursively on the superclass of C.</li>
2134 * <li> Include the results of invoking this algorithm recursively on all
2135 * direct superinterfaces of C, but include only instance methods.</li>
2136 * </ol></li>
2137 * <li> This union is partitioned into subsets of methods with same
2138 * return type (the selection of methods from step 1 also guarantees that
2139 * they have the same method name and parameter types).</li>
2140 * <li> Within each such subset only the most specific methods are selected.
2141 * Let method M be a method from a set of methods with same VM
2142 * signature (return type, name, parameter types).
2143 * M is most specific if there is no such method N != M from the same
2144 * set, such that N is more specific than M. N is more specific than M
2145 * if:
2146 * <ol type="a">
2147 * <li> N is declared by a class and M is declared by an interface; or</li>
2148 * <li> N and M are both declared by classes or both by interfaces and
2149 * N's declaring type is the same as or a subtype of M's declaring type
2150 * (clearly, if M's and N's declaring types are the same type, then
2151 * M and N are the same method).</li>
2152 * </ol></li>
2153 * <li> The result of this algorithm is chosen arbitrarily from the methods
2154 * with most specific return type among all selected methods from step 3.
2155 * Let R be a return type of a method M from the set of all selected methods
2156 * from step 3. M is a method with most specific return type if there is
2157 * no such method N != M from the same set, having return type S != R,
2158 * such that S is a subtype of R as determined by
2159 * R.class.{@link #isAssignableFrom}(S.class).
2160 * </ol>
2161 *
2162 * @apiNote There may be more than one method with matching name and
2163 * parameter types in a class because while the Java language forbids a
2164 * class to declare multiple methods with the same signature but different
2165 * return types, the Java virtual machine does not. This
2166 * increased flexibility in the virtual machine can be used to
2167 * implement various language features. For example, covariant
2168 * returns can be implemented with {@linkplain
2169 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2170 * method and the overriding method would have the same
2171 * signature but different return types. This method would return the
2172 * overriding method as it would have a more specific return type.
2173 *
2174 * @param name the name of the method
2175 * @param parameterTypes the list of parameters
2176 * @return the {@code Method} object that matches the specified
2177 * {@code name} and {@code parameterTypes}
2178 * @throws NoSuchMethodException if a matching method is not found
2179 * or if the name is {@value ConstantDescs#INIT_NAME} or
2180 * {@value ConstantDescs#CLASS_INIT_NAME}.
2181 * @throws NullPointerException if {@code name} is {@code null}
2182 *
2183 * @jls 8.2 Class Members
2184 * @jls 8.4 Method Declarations
2185 * @since 1.1
2186 */
2187 public Method getMethod(String name, Class<?>... parameterTypes)
2188 throws NoSuchMethodException {
2189 Objects.requireNonNull(name);
2190 Method method = getMethod0(name, parameterTypes);
2191 if (method == null) {
2192 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2193 }
2194 return getReflectionFactory().copyMethod(method);
2195 }
2196
2197 /**
2198 * Returns a {@code Constructor} object that reflects the specified
2199 * public constructor of the class represented by this {@code Class}
2200 * object. The {@code parameterTypes} parameter is an array of
2201 * {@code Class} objects that identify the constructor's formal
2202 * parameter types, in declared order.
2203 *
2204 * If this {@code Class} object represents an inner class
2205 * declared in a non-static context, the formal parameter types
2206 * include the explicit enclosing instance as the first parameter.
2207 *
2208 * <p> The constructor to reflect is the public constructor of the class
2209 * represented by this {@code Class} object whose formal parameter
2210 * types match those specified by {@code parameterTypes}.
2211 *
2212 * @param parameterTypes the parameter array
2213 * @return the {@code Constructor} object of the public constructor that
2214 * matches the specified {@code parameterTypes}
2215 * @throws NoSuchMethodException if a matching constructor is not found,
2216 * including when this {@code Class} object represents
2217 * an interface, a primitive type, an array class, or void.
2218 *
2219 * @see #getDeclaredConstructor(Class[])
2220 * @since 1.1
2221 */
2222 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2223 throws NoSuchMethodException {
2224 return getReflectionFactory().copyConstructor(
2225 getConstructor0(parameterTypes, Member.PUBLIC));
2226 }
2227
2228
2229 /**
2230 * Returns an array of {@code Class} objects reflecting all the
2231 * classes and interfaces declared as members of the class represented by
2232 * this {@code Class} object. This includes public, protected, default
2233 * (package) access, and private classes and interfaces declared by the
2234 * class, but excludes inherited classes and interfaces. This method
2235 * returns an array of length 0 if the class declares no classes or
2236 * interfaces as members, or if this {@code Class} object represents a
2237 * primitive type, an array class, or void.
2238 *
2239 * @return the array of {@code Class} objects representing all the
2240 * declared members of this class
2241 *
2242 * @since 1.1
2243 * @jls 8.5 Member Class and Interface Declarations
2244 */
2245 public Class<?>[] getDeclaredClasses() {
2246 return getDeclaredClasses0();
2247 }
2248
2249
2250 /**
2251 * Returns an array of {@code Field} objects reflecting all the fields
2252 * declared by the class or interface represented by this
2253 * {@code Class} object. This includes public, protected, default
2254 * (package) access, and private fields, but excludes inherited fields.
2255 *
2256 * <p> If this {@code Class} object represents a class or interface with no
2257 * declared fields, then this method returns an array of length 0.
2258 *
2259 * <p> If this {@code Class} object represents an array type, a primitive
2260 * type, or void, then this method returns an array of length 0.
2261 *
2262 * <p> The elements in the returned array are not sorted and are not in any
2263 * particular order.
2264 *
2265 * @return the array of {@code Field} objects representing all the
2266 * declared fields of this class
2267 *
2268 * @since 1.1
2269 * @jls 8.2 Class Members
2270 * @jls 8.3 Field Declarations
2271 */
2272 public Field[] getDeclaredFields() {
2273 return copyFields(privateGetDeclaredFields(false));
2274 }
2275
2276 /**
2277 * Returns an array of {@code RecordComponent} objects representing all the
2278 * record components of this record class, or {@code null} if this class is
2279 * not a record class.
2280 *
2281 * <p> The components are returned in the same order that they are declared
2282 * in the record header. The array is empty if this record class has no
2283 * components. If the class is not a record class, that is {@link
2284 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2285 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2286 * returns a non-null value.
2287 *
2288 * @apiNote
2289 * <p> The following method can be used to find the record canonical constructor:
2290 *
2291 * {@snippet lang="java" :
2292 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2293 * throws NoSuchMethodException {
2294 * Class<?>[] paramTypes =
2295 * Arrays.stream(cls.getRecordComponents())
2296 * .map(RecordComponent::getType)
2297 * .toArray(Class<?>[]::new);
2298 * return cls.getDeclaredConstructor(paramTypes);
2299 * }}
2300 *
2301 * @return An array of {@code RecordComponent} objects representing all the
2302 * record components of this record class, or {@code null} if this
2303 * class is not a record class
2304 *
2305 * @jls 8.10 Record Classes
2306 * @since 16
2307 */
2308 public RecordComponent[] getRecordComponents() {
2309 if (!isRecord()) {
2310 return null;
2311 }
2312 return getRecordComponents0();
2313 }
2314
2315 /**
2316 * Returns an array containing {@code Method} objects reflecting all the
2317 * declared methods of the class or interface represented by this {@code
2318 * Class} object, including public, protected, default (package)
2319 * access, and private methods, but excluding inherited methods.
2320 * The declared methods may include methods <em>not</em> in the
2321 * source of the class or interface, including {@linkplain
2322 * Method#isBridge bridge methods} and other {@linkplain
2323 * Executable#isSynthetic synthetic} methods added by compilers.
2324 *
2325 * <p> If this {@code Class} object represents a class or interface that
2326 * has multiple declared methods with the same name and parameter types,
2327 * but different return types, then the returned array has a {@code Method}
2328 * object for each such method.
2329 *
2330 * <p> If this {@code Class} object represents a class or interface that
2331 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2332 * then the returned array does <em>not</em> have a corresponding {@code
2333 * Method} object.
2334 *
2335 * <p> If this {@code Class} object represents a class or interface with no
2336 * declared methods, then the returned array has length 0.
2337 *
2338 * <p> If this {@code Class} object represents an array type, a primitive
2339 * type, or void, then the returned array has length 0.
2340 *
2341 * <p> The elements in the returned array are not sorted and are not in any
2342 * particular order.
2343 *
2344 * @return the array of {@code Method} objects representing all the
2345 * declared methods of this class
2346 *
2347 * @jls 8.2 Class Members
2348 * @jls 8.4 Method Declarations
2349 * @see <a
2350 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2351 * programming language and JVM modeling in core reflection</a>
2352 * @since 1.1
2353 */
2354 public Method[] getDeclaredMethods() {
2355 return copyMethods(privateGetDeclaredMethods(false));
2356 }
2357
2358 /**
2359 * Returns an array of {@code Constructor} objects reflecting all the
2360 * constructors implicitly or explicitly declared by the class represented by this
2361 * {@code Class} object. These are public, protected, default
2362 * (package) access, and private constructors. The elements in the array
2363 * returned are not sorted and are not in any particular order. If the
2364 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2365 * If a record class has a canonical constructor (JLS {@jls
2366 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2367 *
2368 * This method returns an array of length 0 if this {@code Class}
2369 * object represents an interface, a primitive type, an array class, or
2370 * void.
2371 *
2372 * @return the array of {@code Constructor} objects representing all the
2373 * declared constructors of this class
2374 *
2375 * @since 1.1
2376 * @see #getConstructors()
2377 * @jls 8.8 Constructor Declarations
2378 */
2379 public Constructor<?>[] getDeclaredConstructors() {
2380 return copyConstructors(privateGetDeclaredConstructors(false));
2381 }
2382
2383
2384 /**
2385 * Returns a {@code Field} object that reflects the specified declared
2386 * field of the class or interface represented by this {@code Class}
2387 * object. The {@code name} parameter is a {@code String} that specifies
2388 * the simple name of the desired field.
2389 *
2390 * <p> If this {@code Class} object represents an array type, then this
2391 * method does not find the {@code length} field of the array type.
2392 *
2393 * @param name the name of the field
2394 * @return the {@code Field} object for the specified field in this
2395 * class
2396 * @throws NoSuchFieldException if a field with the specified name is
2397 * not found.
2398 * @throws NullPointerException if {@code name} is {@code null}
2399 *
2400 * @since 1.1
2401 * @jls 8.2 Class Members
2402 * @jls 8.3 Field Declarations
2403 */
2404 public Field getDeclaredField(String name) throws NoSuchFieldException {
2405 Objects.requireNonNull(name);
2406 Field field = searchFields(privateGetDeclaredFields(false), name);
2407 if (field == null) {
2408 throw new NoSuchFieldException(name);
2409 }
2410 return getReflectionFactory().copyField(field);
2411 }
2412
2413
2414 /**
2415 * Returns a {@code Method} object that reflects the specified
2416 * declared method of the class or interface represented by this
2417 * {@code Class} object. The {@code name} parameter is a
2418 * {@code String} that specifies the simple name of the desired
2419 * method, and the {@code parameterTypes} parameter is an array of
2420 * {@code Class} objects that identify the method's formal parameter
2421 * types, in declared order. If more than one method with the same
2422 * parameter types is declared in a class, and one of these methods has a
2423 * return type that is more specific than any of the others, that method is
2424 * returned; otherwise one of the methods is chosen arbitrarily. If the
2425 * name is {@value ConstantDescs#INIT_NAME} or {@value
2426 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2427 * is raised.
2428 *
2429 * <p> If this {@code Class} object represents an array type, then this
2430 * method does not find the {@code clone()} method.
2431 *
2432 * @param name the name of the method
2433 * @param parameterTypes the parameter array
2434 * @return the {@code Method} object for the method of this class
2435 * matching the specified name and parameters
2436 * @throws NoSuchMethodException if a matching method is not found.
2437 * @throws NullPointerException if {@code name} is {@code null}
2438 *
2439 * @jls 8.2 Class Members
2440 * @jls 8.4 Method Declarations
2441 * @since 1.1
2442 */
2443 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2444 throws NoSuchMethodException {
2445 Objects.requireNonNull(name);
2446 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2447 if (method == null) {
2448 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2449 }
2450 return getReflectionFactory().copyMethod(method);
2451 }
2452
2453 /**
2454 * Returns the list of {@code Method} objects for the declared public
2455 * methods of this class or interface that have the specified method name
2456 * and parameter types.
2457 *
2458 * @param name the name of the method
2459 * @param parameterTypes the parameter array
2460 * @return the list of {@code Method} objects for the public methods of
2461 * this class matching the specified name and parameters
2462 */
2463 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2464 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2465 ReflectionFactory factory = getReflectionFactory();
2466 List<Method> result = new ArrayList<>();
2467 for (Method method : methods) {
2468 if (method.getName().equals(name)
2469 && Arrays.equals(
2470 factory.getExecutableSharedParameterTypes(method),
2471 parameterTypes)) {
2472 result.add(factory.copyMethod(method));
2473 }
2474 }
2475 return result;
2476 }
2477
2478 /**
2479 * Returns the most specific {@code Method} object of this class, super class or
2480 * interface that have the specified method name and parameter types.
2481 *
2482 * @param publicOnly true if only public methods are examined, otherwise all methods
2483 * @param name the name of the method
2484 * @param parameterTypes the parameter array
2485 * @return the {@code Method} object for the method found from this class matching
2486 * the specified name and parameters, or null if not found
2487 */
2488 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2489 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2490 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2491 }
2492
2493 /**
2494 * Returns a {@code Constructor} object that reflects the specified
2495 * constructor of the class represented by this
2496 * {@code Class} object. The {@code parameterTypes} parameter is
2497 * an array of {@code Class} objects that identify the constructor's
2498 * formal parameter types, in declared order.
2499 *
2500 * If this {@code Class} object represents an inner class
2501 * declared in a non-static context, the formal parameter types
2502 * include the explicit enclosing instance as the first parameter.
2503 *
2504 * @param parameterTypes the parameter array
2505 * @return The {@code Constructor} object for the constructor with the
2506 * specified parameter list
2507 * @throws NoSuchMethodException if a matching constructor is not found,
2508 * including when this {@code Class} object represents
2509 * an interface, a primitive type, an array class, or void.
2510 *
2511 * @see #getConstructor(Class[])
2512 * @since 1.1
2513 */
2514 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2515 throws NoSuchMethodException {
2516 return getReflectionFactory().copyConstructor(
2517 getConstructor0(parameterTypes, Member.DECLARED));
2518 }
2519
2520 /**
2521 * Finds a resource with a given name.
2522 *
2523 * <p> If this class is in a named {@link Module Module} then this method
2524 * will attempt to find the resource in the module. This is done by
2525 * delegating to the module's class loader {@link
2526 * ClassLoader#findResource(String,String) findResource(String,String)}
2527 * method, invoking it with the module name and the absolute name of the
2528 * resource. Resources in named modules are subject to the rules for
2529 * encapsulation specified in the {@code Module} {@link
2530 * Module#getResourceAsStream getResourceAsStream} method and so this
2531 * method returns {@code null} when the resource is a
2532 * non-"{@code .class}" resource in a package that is not open to the
2533 * caller's module.
2534 *
2535 * <p> Otherwise, if this class is not in a named module then the rules for
2536 * searching resources associated with a given class are implemented by the
2537 * defining {@linkplain ClassLoader class loader} of the class. This method
2538 * delegates to this {@code Class} object's class loader.
2539 * If this {@code Class} object was loaded by the bootstrap class loader,
2540 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2541 *
2542 * <p> Before delegation, an absolute resource name is constructed from the
2543 * given resource name using this algorithm:
2544 *
2545 * <ul>
2546 *
2547 * <li> If the {@code name} begins with a {@code '/'}
2548 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2549 * portion of the {@code name} following the {@code '/'}.
2550 *
2551 * <li> Otherwise, the absolute name is of the following form:
2552 *
2553 * <blockquote>
2554 * {@code modified_package_name/name}
2555 * </blockquote>
2556 *
2557 * <p> Where the {@code modified_package_name} is the package name of this
2558 * object with {@code '/'} substituted for {@code '.'}
2559 * (<code>'\u002e'</code>).
2560 *
2561 * </ul>
2562 *
2563 * @param name name of the desired resource
2564 * @return A {@link java.io.InputStream} object; {@code null} if no
2565 * resource with this name is found, or the resource is in a package
2566 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2567 * least the caller module.
2568 * @throws NullPointerException If {@code name} is {@code null}
2569 *
2570 * @see Module#getResourceAsStream(String)
2571 * @since 1.1
2572 */
2573 @CallerSensitive
2574 public InputStream getResourceAsStream(String name) {
2575 name = resolveName(name);
2576
2577 Module thisModule = getModule();
2578 if (thisModule.isNamed()) {
2579 // check if resource can be located by caller
2580 if (Resources.canEncapsulate(name)
2581 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2582 return null;
2583 }
2584
2585 // resource not encapsulated or in package open to caller
2586 String mn = thisModule.getName();
2587 ClassLoader cl = classLoader;
2588 try {
2589
2590 // special-case built-in class loaders to avoid the
2591 // need for a URL connection
2592 if (cl == null) {
2593 return BootLoader.findResourceAsStream(mn, name);
2594 } else if (cl instanceof BuiltinClassLoader bcl) {
2595 return bcl.findResourceAsStream(mn, name);
2596 } else {
2597 URL url = cl.findResource(mn, name);
2598 return (url != null) ? url.openStream() : null;
2599 }
2600
2601 } catch (IOException | SecurityException e) {
2602 return null;
2603 }
2604 }
2605
2606 // unnamed module
2607 ClassLoader cl = classLoader;
2608 if (cl == null) {
2609 return ClassLoader.getSystemResourceAsStream(name);
2610 } else {
2611 return cl.getResourceAsStream(name);
2612 }
2613 }
2614
2615 /**
2616 * Finds a resource with a given name.
2617 *
2618 * <p> If this class is in a named {@link Module Module} then this method
2619 * will attempt to find the resource in the module. This is done by
2620 * delegating to the module's class loader {@link
2621 * ClassLoader#findResource(String,String) findResource(String,String)}
2622 * method, invoking it with the module name and the absolute name of the
2623 * resource. Resources in named modules are subject to the rules for
2624 * encapsulation specified in the {@code Module} {@link
2625 * Module#getResourceAsStream getResourceAsStream} method and so this
2626 * method returns {@code null} when the resource is a
2627 * non-"{@code .class}" resource in a package that is not open to the
2628 * caller's module.
2629 *
2630 * <p> Otherwise, if this class is not in a named module then the rules for
2631 * searching resources associated with a given class are implemented by the
2632 * defining {@linkplain ClassLoader class loader} of the class. This method
2633 * delegates to this {@code Class} object's class loader.
2634 * If this {@code Class} object was loaded by the bootstrap class loader,
2635 * the method delegates to {@link ClassLoader#getSystemResource}.
2636 *
2637 * <p> Before delegation, an absolute resource name is constructed from the
2638 * given resource name using this algorithm:
2639 *
2640 * <ul>
2641 *
2642 * <li> If the {@code name} begins with a {@code '/'}
2643 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2644 * portion of the {@code name} following the {@code '/'}.
2645 *
2646 * <li> Otherwise, the absolute name is of the following form:
2647 *
2648 * <blockquote>
2649 * {@code modified_package_name/name}
2650 * </blockquote>
2651 *
2652 * <p> Where the {@code modified_package_name} is the package name of this
2653 * object with {@code '/'} substituted for {@code '.'}
2654 * (<code>'\u002e'</code>).
2655 *
2656 * </ul>
2657 *
2658 * @param name name of the desired resource
2659 * @return A {@link java.net.URL} object; {@code null} if no resource with
2660 * this name is found, the resource cannot be located by a URL, or the
2661 * resource is in a package that is not
2662 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2663 * module.
2664 * @throws NullPointerException If {@code name} is {@code null}
2665 * @since 1.1
2666 */
2667 @CallerSensitive
2668 public URL getResource(String name) {
2669 name = resolveName(name);
2670
2671 Module thisModule = getModule();
2672 if (thisModule.isNamed()) {
2673 // check if resource can be located by caller
2674 if (Resources.canEncapsulate(name)
2675 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2676 return null;
2677 }
2678
2679 // resource not encapsulated or in package open to caller
2680 String mn = thisModule.getName();
2681 ClassLoader cl = classLoader;
2682 try {
2683 if (cl == null) {
2684 return BootLoader.findResource(mn, name);
2685 } else {
2686 return cl.findResource(mn, name);
2687 }
2688 } catch (IOException ioe) {
2689 return null;
2690 }
2691 }
2692
2693 // unnamed module
2694 ClassLoader cl = classLoader;
2695 if (cl == null) {
2696 return ClassLoader.getSystemResource(name);
2697 } else {
2698 return cl.getResource(name);
2699 }
2700 }
2701
2702 /**
2703 * Returns true if a resource with the given name can be located by the
2704 * given caller. All resources in a module can be located by code in
2705 * the module. For other callers, then the package needs to be open to
2706 * the caller.
2707 */
2708 private boolean isOpenToCaller(String name, Class<?> caller) {
2709 // assert getModule().isNamed();
2710 Module thisModule = getModule();
2711 Module callerModule = (caller != null) ? caller.getModule() : null;
2712 if (callerModule != thisModule) {
2713 String pn = Resources.toPackageName(name);
2714 if (thisModule.getDescriptor().packages().contains(pn)) {
2715 if (callerModule == null) {
2716 // no caller, return true if the package is open to all modules
2717 return thisModule.isOpen(pn);
2718 }
2719 if (!thisModule.isOpen(pn, callerModule)) {
2720 // package not open to caller
2721 return false;
2722 }
2723 }
2724 }
2725 return true;
2726 }
2727
2728 /**
2729 * Returns the {@code ProtectionDomain} of this class.
2730 *
2731 * @return the ProtectionDomain of this class
2732 *
2733 * @see java.security.ProtectionDomain
2734 * @since 1.2
2735 */
2736 public ProtectionDomain getProtectionDomain() {
2737 return protectionDomain();
2738 }
2739
2740 /** Holder for the protection domain returned when the internal domain is null */
2741 private static class Holder {
2742 private static final ProtectionDomain allPermDomain;
2743 static {
2744 Permissions perms = new Permissions();
2745 perms.add(SecurityConstants.ALL_PERMISSION);
2746 allPermDomain = new ProtectionDomain(null, perms);
2747 }
2748 }
2749
2750 // package-private
2751 ProtectionDomain protectionDomain() {
2752 ProtectionDomain pd = getProtectionDomain0();
2753 if (pd == null) {
2754 return Holder.allPermDomain;
2755 } else {
2756 return pd;
2757 }
2758 }
2759
2760 /**
2761 * Returns the ProtectionDomain of this class.
2762 */
2763 private native ProtectionDomain getProtectionDomain0();
2764
2765 /*
2766 * Returns the Class object for the named primitive type. Type parameter T
2767 * avoids redundant casts for trusted code.
2768 */
2769 static native <T> Class<T> getPrimitiveClass(String name);
2770
2771 /**
2772 * Add a package name prefix if the name is not absolute. Remove leading "/"
2773 * if name is absolute
2774 */
2775 private String resolveName(String name) {
2776 if (!name.startsWith("/")) {
2777 String baseName = getPackageName();
2778 if (!baseName.isEmpty()) {
2779 int len = baseName.length() + 1 + name.length();
2780 StringBuilder sb = new StringBuilder(len);
2781 name = sb.append(baseName.replace('.', '/'))
2782 .append('/')
2783 .append(name)
2784 .toString();
2785 }
2786 } else {
2787 name = name.substring(1);
2788 }
2789 return name;
2790 }
2791
2792 /**
2793 * Atomic operations support.
2794 */
2795 private static class Atomic {
2796 // initialize Unsafe machinery here, since we need to call Class.class instance method
2797 // and have to avoid calling it in the static initializer of the Class class...
2798 private static final Unsafe unsafe = Unsafe.getUnsafe();
2799 // offset of Class.reflectionData instance field
2800 private static final long reflectionDataOffset
2801 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2802 // offset of Class.annotationType instance field
2803 private static final long annotationTypeOffset
2804 = unsafe.objectFieldOffset(Class.class, "annotationType");
2805 // offset of Class.annotationData instance field
2806 private static final long annotationDataOffset
2807 = unsafe.objectFieldOffset(Class.class, "annotationData");
2808
2809 static <T> boolean casReflectionData(Class<?> clazz,
2810 ReflectionData<T> oldData,
2811 ReflectionData<T> newData) {
2812 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2813 }
2814
2815 static boolean casAnnotationType(Class<?> clazz,
2816 AnnotationType oldType,
2817 AnnotationType newType) {
2818 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2819 }
2820
2821 static boolean casAnnotationData(Class<?> clazz,
2822 AnnotationData oldData,
2823 AnnotationData newData) {
2824 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2825 }
2826 }
2827
2828 /**
2829 * Reflection support.
2830 */
2831
2832 // Reflection data caches various derived names and reflective members. Cached
2833 // values may be invalidated when JVM TI RedefineClasses() is called
2834 private static class ReflectionData<T> {
2835 volatile Field[] declaredFields;
2836 volatile Field[] publicFields;
2837 volatile Method[] declaredMethods;
2838 volatile Method[] publicMethods;
2839 volatile Constructor<T>[] declaredConstructors;
2840 volatile Constructor<T>[] publicConstructors;
2841 // Intermediate results for getFields and getMethods
2842 volatile Field[] declaredPublicFields;
2843 volatile Method[] declaredPublicMethods;
2844 volatile Class<?>[] interfaces;
2845
2846 // Cached names
2847 String simpleName;
2848 String canonicalName;
2849 static final String NULL_SENTINEL = new String();
2850
2851 // Value of classRedefinedCount when we created this ReflectionData instance
2852 final int redefinedCount;
2853
2854 ReflectionData(int redefinedCount) {
2855 this.redefinedCount = redefinedCount;
2856 }
2857 }
2858
2859 private transient volatile ReflectionData<T> reflectionData;
2860
2861 // Incremented by the VM on each call to JVM TI RedefineClasses()
2862 // that redefines this class or a superclass.
2863 private transient volatile int classRedefinedCount;
2864
2865 // Lazily create and cache ReflectionData
2866 private ReflectionData<T> reflectionData() {
2867 ReflectionData<T> reflectionData = this.reflectionData;
2868 int classRedefinedCount = this.classRedefinedCount;
2869 if (reflectionData != null &&
2870 reflectionData.redefinedCount == classRedefinedCount) {
2871 return reflectionData;
2872 }
2873 // else no SoftReference or cleared SoftReference or stale ReflectionData
2874 // -> create and replace new instance
2875 return newReflectionData(reflectionData, classRedefinedCount);
2876 }
2877
2878 private ReflectionData<T> newReflectionData(ReflectionData<T> oldReflectionData,
2879 int classRedefinedCount) {
2880 while (true) {
2881 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2882 // try to CAS it...
2883 if (Atomic.casReflectionData(this, oldReflectionData, rd)) {
2884 return rd;
2885 }
2886 // else retry
2887 oldReflectionData = this.reflectionData;
2888 classRedefinedCount = this.classRedefinedCount;
2889 if (oldReflectionData != null && oldReflectionData.redefinedCount == classRedefinedCount) {
2890 return rd;
2891 }
2892 }
2893 }
2894
2895 // Generic signature handling
2896 private native String getGenericSignature0();
2897
2898 // Generic info repository; lazily initialized
2899 private transient volatile ClassRepository genericInfo;
2900
2901 // accessor for factory
2902 private GenericsFactory getFactory() {
2903 // create scope and factory
2904 return CoreReflectionFactory.make(this, ClassScope.make(this));
2905 }
2906
2907 // accessor for generic info repository;
2908 // generic info is lazily initialized
2909 private ClassRepository getGenericInfo() {
2910 ClassRepository genericInfo = this.genericInfo;
2911 if (genericInfo == null) {
2912 String signature = getGenericSignature0();
2913 if (signature == null) {
2914 genericInfo = ClassRepository.NONE;
2915 } else {
2916 genericInfo = ClassRepository.make(signature, getFactory());
2917 }
2918 this.genericInfo = genericInfo;
2919 }
2920 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2921 }
2922
2923 // Annotations handling
2924 native byte[] getRawAnnotations();
2925 // Since 1.8
2926 native byte[] getRawTypeAnnotations();
2927 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2928 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2929 }
2930
2931 native ConstantPool getConstantPool();
2932
2933 //
2934 //
2935 // java.lang.reflect.Field handling
2936 //
2937 //
2938
2939 // Returns an array of "root" fields. These Field objects must NOT
2940 // be propagated to the outside world, but must instead be copied
2941 // via ReflectionFactory.copyField.
2942 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2943 Field[] res;
2944 ReflectionData<T> rd = reflectionData();
2945 if (rd != null) {
2946 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2947 if (res != null) return res;
2948 }
2949 // No cached value available; request value from VM
2950 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2951 if (rd != null) {
2952 if (publicOnly) {
2953 rd.declaredPublicFields = res;
2954 } else {
2955 rd.declaredFields = res;
2956 }
2957 }
2958 return res;
2959 }
2960
2961 // Returns an array of "root" fields. These Field objects must NOT
2962 // be propagated to the outside world, but must instead be copied
2963 // via ReflectionFactory.copyField.
2964 private Field[] privateGetPublicFields() {
2965 Field[] res;
2966 ReflectionData<T> rd = reflectionData();
2967 if (rd != null) {
2968 res = rd.publicFields;
2969 if (res != null) return res;
2970 }
2971
2972 // Use a linked hash set to ensure order is preserved and
2973 // fields from common super interfaces are not duplicated
2974 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2975
2976 // Local fields
2977 addAll(fields, privateGetDeclaredFields(true));
2978
2979 // Direct superinterfaces, recursively
2980 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2981 addAll(fields, si.privateGetPublicFields());
2982 }
2983
2984 // Direct superclass, recursively
2985 Class<?> sc = getSuperclass();
2986 if (sc != null) {
2987 addAll(fields, sc.privateGetPublicFields());
2988 }
2989
2990 res = fields.toArray(new Field[0]);
2991 if (rd != null) {
2992 rd.publicFields = res;
2993 }
2994 return res;
2995 }
2996
2997 private static void addAll(Collection<Field> c, Field[] o) {
2998 for (Field f : o) {
2999 c.add(f);
3000 }
3001 }
3002
3003
3004 //
3005 //
3006 // java.lang.reflect.Constructor handling
3007 //
3008 //
3009
3010 // Returns an array of "root" constructors. These Constructor
3011 // objects must NOT be propagated to the outside world, but must
3012 // instead be copied via ReflectionFactory.copyConstructor.
3013 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3014 Constructor<T>[] res;
3015 ReflectionData<T> rd = reflectionData();
3016 if (rd != null) {
3017 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3018 if (res != null) return res;
3019 }
3020 // No cached value available; request value from VM
3021 if (isInterface()) {
3022 @SuppressWarnings("unchecked")
3023 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3024 res = temporaryRes;
3025 } else {
3026 res = getDeclaredConstructors0(publicOnly);
3027 }
3028 if (rd != null) {
3029 if (publicOnly) {
3030 rd.publicConstructors = res;
3031 } else {
3032 rd.declaredConstructors = res;
3033 }
3034 }
3035 return res;
3036 }
3037
3038 //
3039 //
3040 // java.lang.reflect.Method handling
3041 //
3042 //
3043
3044 // Returns an array of "root" methods. These Method objects must NOT
3045 // be propagated to the outside world, but must instead be copied
3046 // via ReflectionFactory.copyMethod.
3047 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3048 Method[] res;
3049 ReflectionData<T> rd = reflectionData();
3050 if (rd != null) {
3051 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3052 if (res != null) return res;
3053 }
3054 // No cached value available; request value from VM
3055 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3056 if (rd != null) {
3057 if (publicOnly) {
3058 rd.declaredPublicMethods = res;
3059 } else {
3060 rd.declaredMethods = res;
3061 }
3062 }
3063 return res;
3064 }
3065
3066 // Returns an array of "root" methods. These Method objects must NOT
3067 // be propagated to the outside world, but must instead be copied
3068 // via ReflectionFactory.copyMethod.
3069 private Method[] privateGetPublicMethods() {
3070 Method[] res;
3071 ReflectionData<T> rd = reflectionData();
3072 if (rd != null) {
3073 res = rd.publicMethods;
3074 if (res != null) return res;
3075 }
3076
3077 // No cached value available; compute value recursively.
3078 // Start by fetching public declared methods...
3079 PublicMethods pms = new PublicMethods();
3080 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3081 pms.merge(m);
3082 }
3083 // ...then recur over superclass methods...
3084 Class<?> sc = getSuperclass();
3085 if (sc != null) {
3086 for (Method m : sc.privateGetPublicMethods()) {
3087 pms.merge(m);
3088 }
3089 }
3090 // ...and finally over direct superinterfaces.
3091 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3092 for (Method m : intf.privateGetPublicMethods()) {
3093 // static interface methods are not inherited
3094 if (!Modifier.isStatic(m.getModifiers())) {
3095 pms.merge(m);
3096 }
3097 }
3098 }
3099
3100 res = pms.toArray();
3101 if (rd != null) {
3102 rd.publicMethods = res;
3103 }
3104 return res;
3105 }
3106
3107
3108 //
3109 // Helpers for fetchers of one field, method, or constructor
3110 //
3111
3112 // This method does not copy the returned Field object!
3113 private static Field searchFields(Field[] fields, String name) {
3114 for (Field field : fields) {
3115 if (field.getName().equals(name)) {
3116 return field;
3117 }
3118 }
3119 return null;
3120 }
3121
3122 // Returns a "root" Field object. This Field object must NOT
3123 // be propagated to the outside world, but must instead be copied
3124 // via ReflectionFactory.copyField.
3125 private Field getField0(String name) {
3126 // Note: the intent is that the search algorithm this routine
3127 // uses be equivalent to the ordering imposed by
3128 // privateGetPublicFields(). It fetches only the declared
3129 // public fields for each class, however, to reduce the number
3130 // of Field objects which have to be created for the common
3131 // case where the field being requested is declared in the
3132 // class which is being queried.
3133 Field res;
3134 // Search declared public fields
3135 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3136 return res;
3137 }
3138 // Direct superinterfaces, recursively
3139 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3140 for (Class<?> c : interfaces) {
3141 if ((res = c.getField0(name)) != null) {
3142 return res;
3143 }
3144 }
3145 // Direct superclass, recursively
3146 if (!isInterface()) {
3147 Class<?> c = getSuperclass();
3148 if (c != null) {
3149 if ((res = c.getField0(name)) != null) {
3150 return res;
3151 }
3152 }
3153 }
3154 return null;
3155 }
3156
3157 // This method does not copy the returned Method object!
3158 private static Method searchMethods(Method[] methods,
3159 String name,
3160 Class<?>[] parameterTypes)
3161 {
3162 ReflectionFactory fact = getReflectionFactory();
3163 Method res = null;
3164 for (Method m : methods) {
3165 if (m.getName().equals(name)
3166 && arrayContentsEq(parameterTypes,
3167 fact.getExecutableSharedParameterTypes(m))
3168 && (res == null
3169 || (res.getReturnType() != m.getReturnType()
3170 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3171 res = m;
3172 }
3173 return res;
3174 }
3175
3176 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3177
3178 // Returns a "root" Method object. This Method object must NOT
3179 // be propagated to the outside world, but must instead be copied
3180 // via ReflectionFactory.copyMethod.
3181 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3182 PublicMethods.MethodList res = getMethodsRecursive(
3183 name,
3184 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3185 /* includeStatic */ true, /* publicOnly */ true);
3186 return res == null ? null : res.getMostSpecific();
3187 }
3188
3189 // Returns a list of "root" Method objects. These Method objects must NOT
3190 // be propagated to the outside world, but must instead be copied
3191 // via ReflectionFactory.copyMethod.
3192 private PublicMethods.MethodList getMethodsRecursive(String name,
3193 Class<?>[] parameterTypes,
3194 boolean includeStatic,
3195 boolean publicOnly) {
3196 // 1st check declared methods
3197 Method[] methods = privateGetDeclaredMethods(publicOnly);
3198 PublicMethods.MethodList res = PublicMethods.MethodList
3199 .filter(methods, name, parameterTypes, includeStatic);
3200 // if there is at least one match among declared methods, we need not
3201 // search any further as such match surely overrides matching methods
3202 // declared in superclass(es) or interface(s).
3203 if (res != null) {
3204 return res;
3205 }
3206
3207 // if there was no match among declared methods,
3208 // we must consult the superclass (if any) recursively...
3209 Class<?> sc = getSuperclass();
3210 if (sc != null) {
3211 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3212 }
3213
3214 // ...and coalesce the superclass methods with methods obtained
3215 // from directly implemented interfaces excluding static methods...
3216 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3217 res = PublicMethods.MethodList.merge(
3218 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3219 }
3220
3221 return res;
3222 }
3223
3224 // Returns a "root" Constructor object. This Constructor object must NOT
3225 // be propagated to the outside world, but must instead be copied
3226 // via ReflectionFactory.copyConstructor.
3227 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3228 int which) throws NoSuchMethodException
3229 {
3230 ReflectionFactory fact = getReflectionFactory();
3231 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3232 for (Constructor<T> constructor : constructors) {
3233 if (arrayContentsEq(parameterTypes,
3234 fact.getExecutableSharedParameterTypes(constructor))) {
3235 return constructor;
3236 }
3237 }
3238 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3239 }
3240
3241 //
3242 // Other helpers and base implementation
3243 //
3244
3245 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3246 if (a1 == null) {
3247 return a2 == null || a2.length == 0;
3248 }
3249
3250 if (a2 == null) {
3251 return a1.length == 0;
3252 }
3253
3254 if (a1.length != a2.length) {
3255 return false;
3256 }
3257
3258 for (int i = 0; i < a1.length; i++) {
3259 if (a1[i] != a2[i]) {
3260 return false;
3261 }
3262 }
3263
3264 return true;
3265 }
3266
3267 private static Field[] copyFields(Field[] arg) {
3268 Field[] out = new Field[arg.length];
3269 ReflectionFactory fact = getReflectionFactory();
3270 for (int i = 0; i < arg.length; i++) {
3271 out[i] = fact.copyField(arg[i]);
3272 }
3273 return out;
3274 }
3275
3276 private static Method[] copyMethods(Method[] arg) {
3277 Method[] out = new Method[arg.length];
3278 ReflectionFactory fact = getReflectionFactory();
3279 for (int i = 0; i < arg.length; i++) {
3280 out[i] = fact.copyMethod(arg[i]);
3281 }
3282 return out;
3283 }
3284
3285 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3286 Constructor<U>[] out = arg.clone();
3287 ReflectionFactory fact = getReflectionFactory();
3288 for (int i = 0; i < out.length; i++) {
3289 out[i] = fact.copyConstructor(out[i]);
3290 }
3291 return out;
3292 }
3293
3294 private native Field[] getDeclaredFields0(boolean publicOnly);
3295 private native Method[] getDeclaredMethods0(boolean publicOnly);
3296 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3297 private native Class<?>[] getDeclaredClasses0();
3298
3299 /*
3300 * Returns an array containing the components of the Record attribute,
3301 * or null if the attribute is not present.
3302 *
3303 * Note that this method returns non-null array on a class with
3304 * the Record attribute even if this class is not a record.
3305 */
3306 private native RecordComponent[] getRecordComponents0();
3307 private native boolean isRecord0();
3308
3309 /**
3310 * Helper method to get the method name from arguments.
3311 */
3312 private String methodToString(String name, Class<?>[] argTypes) {
3313 return getName() + '.' + name +
3314 ((argTypes == null || argTypes.length == 0) ?
3315 "()" :
3316 Arrays.stream(argTypes)
3317 .map(c -> c == null ? "null" : c.getName())
3318 .collect(Collectors.joining(",", "(", ")")));
3319 }
3320
3321 /** use serialVersionUID from JDK 1.1 for interoperability */
3322 @java.io.Serial
3323 private static final long serialVersionUID = 3206093459760846163L;
3324
3325
3326 /**
3327 * Class Class is special cased within the Serialization Stream Protocol.
3328 *
3329 * A Class instance is written initially into an ObjectOutputStream in the
3330 * following format:
3331 * <pre>
3332 * {@code TC_CLASS} ClassDescriptor
3333 * A ClassDescriptor is a special cased serialization of
3334 * a {@code java.io.ObjectStreamClass} instance.
3335 * </pre>
3336 * A new handle is generated for the initial time the class descriptor
3337 * is written into the stream. Future references to the class descriptor
3338 * are written as references to the initial class descriptor instance.
3339 *
3340 * @see java.io.ObjectStreamClass
3341 */
3342 @java.io.Serial
3343 private static final ObjectStreamField[] serialPersistentFields =
3344 new ObjectStreamField[0];
3345
3346
3347 /**
3348 * Returns the assertion status that would be assigned to this
3349 * class if it were to be initialized at the time this method is invoked.
3350 * If this class has had its assertion status set, the most recent
3351 * setting will be returned; otherwise, if any package default assertion
3352 * status pertains to this class, the most recent setting for the most
3353 * specific pertinent package default assertion status is returned;
3354 * otherwise, if this class is not a system class (i.e., it has a
3355 * class loader) its class loader's default assertion status is returned;
3356 * otherwise, the system class default assertion status is returned.
3357 *
3358 * @apiNote
3359 * Few programmers will have any need for this method; it is provided
3360 * for the benefit of the JDK itself. (It allows a class to determine at
3361 * the time that it is initialized whether assertions should be enabled.)
3362 * Note that this method is not guaranteed to return the actual
3363 * assertion status that was (or will be) associated with the specified
3364 * class when it was (or will be) initialized.
3365 *
3366 * @return the desired assertion status of the specified class.
3367 * @see java.lang.ClassLoader#setClassAssertionStatus
3368 * @see java.lang.ClassLoader#setPackageAssertionStatus
3369 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3370 * @since 1.4
3371 */
3372 public boolean desiredAssertionStatus() {
3373 ClassLoader loader = classLoader;
3374 // If the loader is null this is a system class, so ask the VM
3375 if (loader == null)
3376 return desiredAssertionStatus0(this);
3377
3378 // If the classloader has been initialized with the assertion
3379 // directives, ask it. Otherwise, ask the VM.
3380 synchronized(loader.assertionLock) {
3381 if (loader.classAssertionStatus != null) {
3382 return loader.desiredAssertionStatus(getName());
3383 }
3384 }
3385 return desiredAssertionStatus0(this);
3386 }
3387
3388 // Retrieves the desired assertion status of this class from the VM
3389 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3390
3391 /**
3392 * Returns true if and only if this class was declared as an enum in the
3393 * source code.
3394 *
3395 * Note that {@link java.lang.Enum} is not itself an enum class.
3396 *
3397 * Also note that if an enum constant is declared with a class body,
3398 * the class of that enum constant object is an anonymous class
3399 * and <em>not</em> the class of the declaring enum class. The
3400 * {@link Enum#getDeclaringClass} method of an enum constant can
3401 * be used to get the class of the enum class declaring the
3402 * constant.
3403 *
3404 * @return true if and only if this class was declared as an enum in the
3405 * source code
3406 * @since 1.5
3407 * @jls 8.9.1 Enum Constants
3408 */
3409 public boolean isEnum() {
3410 // An enum must both directly extend java.lang.Enum and have
3411 // the ENUM bit set; classes for specialized enum constants
3412 // don't do the former.
3413 return (this.getModifiers() & ENUM) != 0 &&
3414 this.getSuperclass() == java.lang.Enum.class;
3415 }
3416
3417 /**
3418 * Returns {@code true} if and only if this class is a record class.
3419 *
3420 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3421 * class is {@code java.lang.Record}. A record class is {@linkplain
3422 * Modifier#FINAL final}. A record class has (possibly zero) record
3423 * components; {@link #getRecordComponents()} returns a non-null but
3424 * possibly empty value for a record.
3425 *
3426 * <p> Note that class {@link Record} is not a record class and thus
3427 * invoking this method on class {@code Record} returns {@code false}.
3428 *
3429 * @return true if and only if this class is a record class, otherwise false
3430 * @jls 8.10 Record Classes
3431 * @since 16
3432 */
3433 public boolean isRecord() {
3434 // this superclass and final modifier check is not strictly necessary
3435 // they are intrinsified and serve as a fast-path check
3436 return getSuperclass() == java.lang.Record.class &&
3437 (this.getModifiers() & Modifier.FINAL) != 0 &&
3438 isRecord0();
3439 }
3440
3441 // Fetches the factory for reflective objects
3442 private static ReflectionFactory getReflectionFactory() {
3443 var factory = reflectionFactory;
3444 if (factory != null) {
3445 return factory;
3446 }
3447 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3448 }
3449 private static ReflectionFactory reflectionFactory;
3450
3451 /**
3452 * When CDS is enabled, the Class class may be aot-initialized. However,
3453 * we can't archive reflectionFactory, so we reset it to null, so it
3454 * will be allocated again at runtime.
3455 */
3456 private static void resetArchivedStates() {
3457 reflectionFactory = null;
3458 }
3459
3460 /**
3461 * Returns the elements of this enum class or null if this
3462 * Class object does not represent an enum class.
3463 *
3464 * @return an array containing the values comprising the enum class
3465 * represented by this {@code Class} object in the order they're
3466 * declared, or null if this {@code Class} object does not
3467 * represent an enum class
3468 * @since 1.5
3469 * @jls 8.9.1 Enum Constants
3470 */
3471 public T[] getEnumConstants() {
3472 T[] values = getEnumConstantsShared();
3473 return (values != null) ? values.clone() : null;
3474 }
3475
3476 /**
3477 * Returns the elements of this enum class or null if this
3478 * Class object does not represent an enum class;
3479 * identical to getEnumConstants except that the result is
3480 * uncloned, cached, and shared by all callers.
3481 */
3482 T[] getEnumConstantsShared() {
3483 T[] constants = enumConstants;
3484 if (constants == null) {
3485 if (!isEnum()) return null;
3486 try {
3487 final Method values = getMethod("values");
3488 values.setAccessible(true);
3489 @SuppressWarnings("unchecked")
3490 T[] temporaryConstants = (T[])values.invoke(null);
3491 enumConstants = constants = temporaryConstants;
3492 }
3493 // These can happen when users concoct enum-like classes
3494 // that don't comply with the enum spec.
3495 catch (InvocationTargetException | NoSuchMethodException |
3496 IllegalAccessException | NullPointerException |
3497 ClassCastException ex) { return null; }
3498 }
3499 return constants;
3500 }
3501 private transient volatile T[] enumConstants;
3502
3503 /**
3504 * Returns a map from simple name to enum constant. This package-private
3505 * method is used internally by Enum to implement
3506 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3507 * efficiently. Note that the map is returned by this method is
3508 * created lazily on first use. Typically it won't ever get created.
3509 */
3510 Map<String, T> enumConstantDirectory() {
3511 Map<String, T> directory = enumConstantDirectory;
3512 if (directory == null) {
3513 T[] universe = getEnumConstantsShared();
3514 if (universe == null)
3515 throw new IllegalArgumentException(
3516 getName() + " is not an enum class");
3517 directory = HashMap.newHashMap(universe.length);
3518 for (T constant : universe) {
3519 directory.put(((Enum<?>)constant).name(), constant);
3520 }
3521 enumConstantDirectory = directory;
3522 }
3523 return directory;
3524 }
3525 private transient volatile Map<String, T> enumConstantDirectory;
3526
3527 /**
3528 * Casts an object to the class or interface represented
3529 * by this {@code Class} object.
3530 *
3531 * @param obj the object to be cast
3532 * @return the object after casting, or null if obj is null
3533 *
3534 * @throws ClassCastException if the object is not
3535 * null and is not assignable to the type T.
3536 *
3537 * @since 1.5
3538 */
3539 @SuppressWarnings("unchecked")
3540 @IntrinsicCandidate
3541 public T cast(Object obj) {
3542 if (obj != null && !isInstance(obj))
3543 throw new ClassCastException(cannotCastMsg(obj));
3544 return (T) obj;
3545 }
3546
3547 private String cannotCastMsg(Object obj) {
3548 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3549 }
3550
3551 /**
3552 * Casts this {@code Class} object to represent a subclass of the class
3553 * represented by the specified class object. Checks that the cast
3554 * is valid, and throws a {@code ClassCastException} if it is not. If
3555 * this method succeeds, it always returns a reference to this {@code Class} object.
3556 *
3557 * <p>This method is useful when a client needs to "narrow" the type of
3558 * a {@code Class} object to pass it to an API that restricts the
3559 * {@code Class} objects that it is willing to accept. A cast would
3560 * generate a compile-time warning, as the correctness of the cast
3561 * could not be checked at runtime (because generic types are implemented
3562 * by erasure).
3563 *
3564 * @param <U> the type to cast this {@code Class} object to
3565 * @param clazz the class of the type to cast this {@code Class} object to
3566 * @return this {@code Class} object, cast to represent a subclass of
3567 * the specified class object.
3568 * @throws ClassCastException if this {@code Class} object does not
3569 * represent a subclass of the specified class (here "subclass" includes
3570 * the class itself).
3571 * @since 1.5
3572 */
3573 @SuppressWarnings("unchecked")
3574 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3575 if (clazz.isAssignableFrom(this))
3576 return (Class<? extends U>) this;
3577 else
3578 throw new ClassCastException(this.toString());
3579 }
3580
3581 /**
3582 * {@inheritDoc}
3583 * <p>Note that any annotation returned by this method is a
3584 * declaration annotation.
3585 *
3586 * @throws NullPointerException {@inheritDoc}
3587 * @since 1.5
3588 */
3589 @Override
3590 @SuppressWarnings("unchecked")
3591 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3592 Objects.requireNonNull(annotationClass);
3593
3594 return (A) annotationData().annotations.get(annotationClass);
3595 }
3596
3597 /**
3598 * {@inheritDoc}
3599 * @throws NullPointerException {@inheritDoc}
3600 * @since 1.5
3601 */
3602 @Override
3603 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3604 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3605 }
3606
3607 /**
3608 * {@inheritDoc}
3609 * <p>Note that any annotations returned by this method are
3610 * declaration annotations.
3611 *
3612 * @throws NullPointerException {@inheritDoc}
3613 * @since 1.8
3614 */
3615 @Override
3616 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3617 Objects.requireNonNull(annotationClass);
3618
3619 AnnotationData annotationData = annotationData();
3620 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3621 this,
3622 annotationClass);
3623 }
3624
3625 /**
3626 * {@inheritDoc}
3627 * <p>Note that any annotations returned by this method are
3628 * declaration annotations.
3629 *
3630 * @since 1.5
3631 */
3632 @Override
3633 public Annotation[] getAnnotations() {
3634 return AnnotationParser.toArray(annotationData().annotations);
3635 }
3636
3637 /**
3638 * {@inheritDoc}
3639 * <p>Note that any annotation returned by this method is a
3640 * declaration annotation.
3641 *
3642 * @throws NullPointerException {@inheritDoc}
3643 * @since 1.8
3644 */
3645 @Override
3646 @SuppressWarnings("unchecked")
3647 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3648 Objects.requireNonNull(annotationClass);
3649
3650 return (A) annotationData().declaredAnnotations.get(annotationClass);
3651 }
3652
3653 /**
3654 * {@inheritDoc}
3655 * <p>Note that any annotations returned by this method are
3656 * declaration annotations.
3657 *
3658 * @throws NullPointerException {@inheritDoc}
3659 * @since 1.8
3660 */
3661 @Override
3662 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3663 Objects.requireNonNull(annotationClass);
3664
3665 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3666 annotationClass);
3667 }
3668
3669 /**
3670 * {@inheritDoc}
3671 * <p>Note that any annotations returned by this method are
3672 * declaration annotations.
3673 *
3674 * @since 1.5
3675 */
3676 @Override
3677 public Annotation[] getDeclaredAnnotations() {
3678 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3679 }
3680
3681 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3682 private static class AnnotationData {
3683 final Map<Class<? extends Annotation>, Annotation> annotations;
3684 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3685
3686 // Value of classRedefinedCount when we created this AnnotationData instance
3687 final int redefinedCount;
3688
3689 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3690 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3691 int redefinedCount) {
3692 this.annotations = annotations;
3693 this.declaredAnnotations = declaredAnnotations;
3694 this.redefinedCount = redefinedCount;
3695 }
3696 }
3697
3698 // Annotations cache
3699 @SuppressWarnings("UnusedDeclaration")
3700 private transient volatile AnnotationData annotationData;
3701
3702 private AnnotationData annotationData() {
3703 while (true) { // retry loop
3704 AnnotationData annotationData = this.annotationData;
3705 int classRedefinedCount = this.classRedefinedCount;
3706 if (annotationData != null &&
3707 annotationData.redefinedCount == classRedefinedCount) {
3708 return annotationData;
3709 }
3710 // null or stale annotationData -> optimistically create new instance
3711 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3712 // try to install it
3713 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3714 // successfully installed new AnnotationData
3715 return newAnnotationData;
3716 }
3717 }
3718 }
3719
3720 private AnnotationData createAnnotationData(int classRedefinedCount) {
3721 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3722 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3723 Class<?> superClass = getSuperclass();
3724 Map<Class<? extends Annotation>, Annotation> annotations = null;
3725 if (superClass != null) {
3726 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3727 superClass.annotationData().annotations;
3728 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3729 Class<? extends Annotation> annotationClass = e.getKey();
3730 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3731 if (annotations == null) { // lazy construction
3732 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3733 declaredAnnotations.size(),
3734 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3735 )
3736 );
3737 }
3738 annotations.put(annotationClass, e.getValue());
3739 }
3740 }
3741 }
3742 if (annotations == null) {
3743 // no inherited annotations -> share the Map with declaredAnnotations
3744 annotations = declaredAnnotations;
3745 } else {
3746 // at least one inherited annotation -> declared may override inherited
3747 annotations.putAll(declaredAnnotations);
3748 }
3749 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3750 }
3751
3752 // Annotation interfaces cache their internal (AnnotationType) form
3753
3754 @SuppressWarnings("UnusedDeclaration")
3755 private transient volatile AnnotationType annotationType;
3756
3757 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3758 return Atomic.casAnnotationType(this, oldType, newType);
3759 }
3760
3761 AnnotationType getAnnotationType() {
3762 return annotationType;
3763 }
3764
3765 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3766 return annotationData().declaredAnnotations;
3767 }
3768
3769 /* Backing store of user-defined values pertaining to this class.
3770 * Maintained by the ClassValue class.
3771 */
3772 transient ClassValue.ClassValueMap classValueMap;
3773
3774 /**
3775 * Returns an {@code AnnotatedType} object that represents the use of a
3776 * type to specify the superclass of the entity represented by this {@code
3777 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3778 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3779 * Foo.)
3780 *
3781 * <p> If this {@code Class} object represents a class whose declaration
3782 * does not explicitly indicate an annotated superclass, then the return
3783 * value is an {@code AnnotatedType} object representing an element with no
3784 * annotations.
3785 *
3786 * <p> If this {@code Class} represents either the {@code Object} class, an
3787 * interface type, an array type, a primitive type, or void, the return
3788 * value is {@code null}.
3789 *
3790 * @return an object representing the superclass
3791 * @since 1.8
3792 */
3793 public AnnotatedType getAnnotatedSuperclass() {
3794 if (this == Object.class ||
3795 isInterface() ||
3796 isArray() ||
3797 isPrimitive() ||
3798 this == Void.TYPE) {
3799 return null;
3800 }
3801
3802 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3803 }
3804
3805 /**
3806 * Returns an array of {@code AnnotatedType} objects that represent the use
3807 * of types to specify superinterfaces of the entity represented by this
3808 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3809 * superinterface in '... implements Foo' is distinct from the
3810 * <em>declaration</em> of interface Foo.)
3811 *
3812 * <p> If this {@code Class} object represents a class, the return value is
3813 * an array containing objects representing the uses of interface types to
3814 * specify interfaces implemented by the class. The order of the objects in
3815 * the array corresponds to the order of the interface types used in the
3816 * 'implements' clause of the declaration of this {@code Class} object.
3817 *
3818 * <p> If this {@code Class} object represents an interface, the return
3819 * value is an array containing objects representing the uses of interface
3820 * types to specify interfaces directly extended by the interface. The
3821 * order of the objects in the array corresponds to the order of the
3822 * interface types used in the 'extends' clause of the declaration of this
3823 * {@code Class} object.
3824 *
3825 * <p> If this {@code Class} object represents a class or interface whose
3826 * declaration does not explicitly indicate any annotated superinterfaces,
3827 * the return value is an array of length 0.
3828 *
3829 * <p> If this {@code Class} object represents either the {@code Object}
3830 * class, an array type, a primitive type, or void, the return value is an
3831 * array of length 0.
3832 *
3833 * @return an array representing the superinterfaces
3834 * @since 1.8
3835 */
3836 public AnnotatedType[] getAnnotatedInterfaces() {
3837 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3838 }
3839
3840 private native Class<?> getNestHost0();
3841
3842 /**
3843 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3844 * or interface represented by this {@code Class} object belongs.
3845 * Every class and interface belongs to exactly one nest.
3846 *
3847 * If the nest host of this class or interface has previously
3848 * been determined, then this method returns the nest host.
3849 * If the nest host of this class or interface has
3850 * not previously been determined, then this method determines the nest
3851 * host using the algorithm of JVMS 5.4.4, and returns it.
3852 *
3853 * Often, a class or interface belongs to a nest consisting only of itself,
3854 * in which case this method returns {@code this} to indicate that the class
3855 * or interface is the nest host.
3856 *
3857 * <p>If this {@code Class} object represents a primitive type, an array type,
3858 * or {@code void}, then this method returns {@code this},
3859 * indicating that the represented entity belongs to the nest consisting only of
3860 * itself, and is the nest host.
3861 *
3862 * @return the nest host of this class or interface
3863 *
3864 * @since 11
3865 * @jvms 4.7.28 The {@code NestHost} Attribute
3866 * @jvms 4.7.29 The {@code NestMembers} Attribute
3867 * @jvms 5.4.4 Access Control
3868 */
3869 public Class<?> getNestHost() {
3870 if (isPrimitive() || isArray()) {
3871 return this;
3872 }
3873 return getNestHost0();
3874 }
3875
3876 /**
3877 * Determines if the given {@code Class} is a nestmate of the
3878 * class or interface represented by this {@code Class} object.
3879 * Two classes or interfaces are nestmates
3880 * if they have the same {@linkplain #getNestHost() nest host}.
3881 *
3882 * @param c the class to check
3883 * @return {@code true} if this class and {@code c} are members of
3884 * the same nest; and {@code false} otherwise.
3885 *
3886 * @since 11
3887 */
3888 public boolean isNestmateOf(Class<?> c) {
3889 if (this == c) {
3890 return true;
3891 }
3892 if (isPrimitive() || isArray() ||
3893 c.isPrimitive() || c.isArray()) {
3894 return false;
3895 }
3896
3897 return getNestHost() == c.getNestHost();
3898 }
3899
3900 private native Class<?>[] getNestMembers0();
3901
3902 /**
3903 * Returns an array containing {@code Class} objects representing all the
3904 * classes and interfaces that are members of the nest to which the class
3905 * or interface represented by this {@code Class} object belongs.
3906 *
3907 * First, this method obtains the {@linkplain #getNestHost() nest host},
3908 * {@code H}, of the nest to which the class or interface represented by
3909 * this {@code Class} object belongs. The zeroth element of the returned
3910 * array is {@code H}.
3911 *
3912 * Then, for each class or interface {@code C} which is recorded by {@code H}
3913 * as being a member of its nest, this method attempts to obtain the {@code Class}
3914 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3915 * loader} of the current {@code Class} object), and then obtains the
3916 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3917 * The classes and interfaces which are recorded by {@code H} as being members
3918 * of its nest, and for which {@code H} can be determined as their nest host,
3919 * are indicated by subsequent elements of the returned array. The order of
3920 * such elements is unspecified. Duplicates are permitted.
3921 *
3922 * <p>If this {@code Class} object represents a primitive type, an array type,
3923 * or {@code void}, then this method returns a single-element array containing
3924 * {@code this}.
3925 *
3926 * @apiNote
3927 * The returned array includes only the nest members recorded in the {@code NestMembers}
3928 * attribute, and not any hidden classes that were added to the nest via
3929 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3930 * Lookup::defineHiddenClass}.
3931 *
3932 * @return an array of all classes and interfaces in the same nest as
3933 * this class or interface
3934 *
3935 * @since 11
3936 * @see #getNestHost()
3937 * @jvms 4.7.28 The {@code NestHost} Attribute
3938 * @jvms 4.7.29 The {@code NestMembers} Attribute
3939 */
3940 public Class<?>[] getNestMembers() {
3941 if (isPrimitive() || isArray()) {
3942 return new Class<?>[] { this };
3943 }
3944 Class<?>[] members = getNestMembers0();
3945 // Can't actually enable this due to bootstrapping issues
3946 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3947 return members;
3948 }
3949
3950 /**
3951 * Returns the descriptor string of the entity (class, interface, array class,
3952 * primitive type, or {@code void}) represented by this {@code Class} object.
3953 *
3954 * <p> If this {@code Class} object represents a class or interface,
3955 * not an array class, then:
3956 * <ul>
3957 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3958 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3959 * for the class or interface. Calling
3960 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3961 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3962 * describing this class or interface.
3963 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3964 * then the result is a string of the form:
3965 * <blockquote>
3966 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3967 * </blockquote>
3968 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3969 * encoded in internal form indicated by the {@code class} file passed to
3970 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3971 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3972 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3973 * The result string is not a type descriptor.
3974 * </ul>
3975 *
3976 * <p> If this {@code Class} object represents an array class, then
3977 * the result is a string consisting of one or more '{@code [}' characters
3978 * representing the depth of the array nesting, followed by the
3979 * descriptor string of the element type.
3980 * <ul>
3981 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3982 * or interface, then this array class can be described nominally.
3983 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3984 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3985 * describing this array class.
3986 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3987 * interface, then this array class cannot be described nominally.
3988 * The result string is not a type descriptor.
3989 * </ul>
3990 *
3991 * <p> If this {@code Class} object represents a primitive type or
3992 * {@code void}, then the result is a field descriptor string which
3993 * is a one-letter code corresponding to a primitive type or {@code void}
3994 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3995 *
3996 * @return the descriptor string for this {@code Class} object
3997 * @jvms 4.3.2 Field Descriptors
3998 * @since 12
3999 */
4000 @Override
4001 public String descriptorString() {
4002 if (isPrimitive())
4003 return Wrapper.forPrimitiveType(this).basicTypeString();
4004
4005 if (isArray()) {
4006 return "[".concat(componentType.descriptorString());
4007 } else if (isHidden()) {
4008 String name = getName();
4009 int index = name.indexOf('/');
4010 return new StringBuilder(name.length() + 2)
4011 .append('L')
4012 .append(name.substring(0, index).replace('.', '/'))
4013 .append('.')
4014 .append(name, index + 1, name.length())
4015 .append(';')
4016 .toString();
4017 } else {
4018 String name = getName().replace('.', '/');
4019 return StringConcatHelper.concat("L", name, ";");
4020 }
4021 }
4022
4023 /**
4024 * Returns the component type of this {@code Class}, if it describes
4025 * an array type, or {@code null} otherwise.
4026 *
4027 * @implSpec
4028 * Equivalent to {@link Class#getComponentType()}.
4029 *
4030 * @return a {@code Class} describing the component type, or {@code null}
4031 * if this {@code Class} does not describe an array type
4032 * @since 12
4033 */
4034 @Override
4035 public Class<?> componentType() {
4036 return isArray() ? componentType : null;
4037 }
4038
4039 /**
4040 * Returns a {@code Class} for an array type whose component type
4041 * is described by this {@linkplain Class}.
4042 *
4043 * @throws UnsupportedOperationException if this component type is {@linkplain
4044 * Void#TYPE void} or if the number of dimensions of the resulting array
4045 * type would exceed 255.
4046 * @return a {@code Class} describing the array type
4047 * @jvms 4.3.2 Field Descriptors
4048 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4049 * @since 12
4050 */
4051 @Override
4052 public Class<?> arrayType() {
4053 try {
4054 return Array.newInstance(this, 0).getClass();
4055 } catch (IllegalArgumentException iae) {
4056 throw new UnsupportedOperationException(iae);
4057 }
4058 }
4059
4060 /**
4061 * Returns a nominal descriptor for this instance, if one can be
4062 * constructed, or an empty {@link Optional} if one cannot be.
4063 *
4064 * @return An {@link Optional} containing the resulting nominal descriptor,
4065 * or an empty {@link Optional} if one cannot be constructed.
4066 * @since 12
4067 */
4068 @Override
4069 public Optional<ClassDesc> describeConstable() {
4070 Class<?> c = isArray() ? elementType() : this;
4071 return c.isHidden() ? Optional.empty()
4072 : Optional.of(ConstantUtils.classDesc(this));
4073 }
4074
4075 /**
4076 * Returns {@code true} if and only if the underlying class is a hidden class.
4077 *
4078 * @return {@code true} if and only if this class is a hidden class.
4079 *
4080 * @since 15
4081 * @see MethodHandles.Lookup#defineHiddenClass
4082 * @see Class##hiddenClasses Hidden Classes
4083 */
4084 @IntrinsicCandidate
4085 public native boolean isHidden();
4086
4087 /**
4088 * Returns an array containing {@code Class} objects representing the
4089 * direct subinterfaces or subclasses permitted to extend or
4090 * implement this class or interface if it is sealed. The order of such elements
4091 * is unspecified. The array is empty if this sealed class or interface has no
4092 * permitted subclass. If this {@code Class} object represents a primitive type,
4093 * {@code void}, an array type, or a class or interface that is not sealed,
4094 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4095 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4096 * returns a non-null value.
4097 *
4098 * For each class or interface {@code C} which is recorded as a permitted
4099 * direct subinterface or subclass of this class or interface,
4100 * this method attempts to obtain the {@code Class}
4101 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4102 * loader} of the current {@code Class} object).
4103 * The {@code Class} objects which can be obtained and which are direct
4104 * subinterfaces or subclasses of this class or interface,
4105 * are indicated by elements of the returned array. If a {@code Class} object
4106 * cannot be obtained, it is silently ignored, and not included in the result
4107 * array.
4108 *
4109 * @return an array of {@code Class} objects of the permitted subclasses of this class
4110 * or interface, or {@code null} if this class or interface is not sealed.
4111 *
4112 * @jls 8.1 Class Declarations
4113 * @jls 9.1 Interface Declarations
4114 * @since 17
4115 */
4116 public Class<?>[] getPermittedSubclasses() {
4117 Class<?>[] subClasses;
4118 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4119 return null;
4120 }
4121 if (subClasses.length > 0) {
4122 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4123 subClasses = Arrays.stream(subClasses)
4124 .filter(this::isDirectSubType)
4125 .toArray(s -> new Class<?>[s]);
4126 }
4127 }
4128 return subClasses;
4129 }
4130
4131 private boolean isDirectSubType(Class<?> c) {
4132 if (isInterface()) {
4133 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4134 if (i == this) {
4135 return true;
4136 }
4137 }
4138 } else {
4139 return c.getSuperclass() == this;
4140 }
4141 return false;
4142 }
4143
4144 /**
4145 * Returns {@code true} if and only if this {@code Class} object represents
4146 * a sealed class or interface. If this {@code Class} object represents a
4147 * primitive type, {@code void}, or an array type, this method returns
4148 * {@code false}. A sealed class or interface has (possibly zero) permitted
4149 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4150 * possibly empty value for a sealed class or interface.
4151 *
4152 * @return {@code true} if and only if this {@code Class} object represents
4153 * a sealed class or interface.
4154 *
4155 * @jls 8.1 Class Declarations
4156 * @jls 9.1 Interface Declarations
4157 * @since 17
4158 */
4159 public boolean isSealed() {
4160 if (isArray() || isPrimitive()) {
4161 return false;
4162 }
4163 return getPermittedSubclasses() != null;
4164 }
4165
4166 private native Class<?>[] getPermittedSubclasses0();
4167
4168 /*
4169 * Return the class's major and minor class file version packed into an int.
4170 * The high order 16 bits contain the class's minor version. The low order
4171 * 16 bits contain the class's major version.
4172 *
4173 * If the class is an array type then the class file version of its element
4174 * type is returned. If the class is a primitive type then the latest class
4175 * file major version is returned and zero is returned for the minor version.
4176 */
4177 private int getClassFileVersion() {
4178 Class<?> c = isArray() ? elementType() : this;
4179 return c.getClassFileVersion0();
4180 }
4181
4182 private native int getClassFileVersion0();
4183
4184 /*
4185 * Return the access flags as they were in the class's bytecode, including
4186 * the original setting of ACC_SUPER.
4187 *
4188 * If the class is an array type then the access flags of the element type is
4189 * returned. If the class is a primitive then ACC_ABSTRACT | ACC_FINAL | ACC_PUBLIC.
4190 */
4191 private int getClassAccessFlagsRaw() {
4192 Class<?> c = isArray() ? elementType() : this;
4193 return c.getClassAccessFlagsRaw0();
4194 }
4195
4196 private native int getClassAccessFlagsRaw0();
4197
4198 // Support for "OLD" CDS workflow -- {
4199 private static final int RD_PUBLIC_METHODS = (1 << 0);
4200 private static final int RD_PUBLIC_FIELDS = (1 << 1);
4201 private static final int RD_DECLARED_CTORS = (1 << 2);
4202 private static final int RD_PUBLIC_CTORS = (1 << 3);
4203 private static final int RD_DECLARED_METHODS = (1 << 4);
4204 private static final int RD_DECLARED_PUBLIC_METHODS = (1 << 5);
4205 private static final int RD_DECLARED_FIELDS = (1 << 6);
4206 private static final int RD_DECLARED_PUBLIC_FIELDS = (1 << 7);
4207 private static final int RD_DECLARED_INTERFACES = (1 << 8);
4208 private static final int RD_DECLARED_SIMPLE_NAME = (1 << 9);
4209 private static final int RD_DECLARED_CANONICAL_NAME = (1 << 10);
4210 private static final int CLS_NAME = (1 << 10);
4211
4212
4213 private int encodeReflectionData() {
4214 int flags = CLS_NAME;
4215 if (reflectionData != null) {
4216 flags = (reflectionData.publicMethods != null ? RD_PUBLIC_METHODS : 0) |
4217 (reflectionData.publicFields != null ? RD_PUBLIC_FIELDS : 0) |
4218 (reflectionData.declaredConstructors != null ? RD_DECLARED_CTORS : 0) |
4219 (reflectionData.publicConstructors != null ? RD_PUBLIC_CTORS : 0) |
4220 (reflectionData.declaredMethods != null ? RD_DECLARED_METHODS : 0) |
4221 (reflectionData.declaredPublicMethods != null ? RD_DECLARED_PUBLIC_METHODS : 0) |
4222 (reflectionData.declaredFields != null ? RD_DECLARED_FIELDS : 0) |
4223 (reflectionData.declaredPublicFields != null ? RD_DECLARED_PUBLIC_FIELDS : 0) |
4224 (reflectionData.interfaces != null ? RD_DECLARED_INTERFACES : 0) |
4225 (reflectionData.simpleName != null ? RD_DECLARED_SIMPLE_NAME : 0) |
4226 (reflectionData.canonicalName != null ? RD_DECLARED_CANONICAL_NAME : 0);
4227 }
4228 return flags;
4229 }
4230 private void generateReflectionData(int flags) {
4231 if ((flags & CLS_NAME ) != 0) { getName(); } // String name
4232 if ((flags & RD_PUBLIC_METHODS ) != 0) { privateGetPublicMethods(); } // Method[] publicMethods;
4233 if ((flags & RD_PUBLIC_FIELDS ) != 0) { privateGetPublicFields(); } // Field[] publicFields;
4234 if ((flags & RD_DECLARED_CTORS ) != 0) { privateGetDeclaredConstructors(false); } // Constructor<T>[] declaredConstructors;
4235 if ((flags & RD_PUBLIC_CTORS ) != 0) { privateGetDeclaredConstructors(true); } // Constructor<T>[] publicConstructors;
4236 if ((flags & RD_DECLARED_METHODS ) != 0) { privateGetDeclaredMethods(false); } // Method[] declaredMethods;
4237 if ((flags & RD_DECLARED_PUBLIC_METHODS) != 0) { privateGetDeclaredMethods(true); } // Method[] declaredPublicMethods;
4238 if ((flags & RD_DECLARED_FIELDS ) != 0) { privateGetDeclaredFields(false); } // Field[] declaredFields;
4239 if ((flags & RD_DECLARED_PUBLIC_FIELDS ) != 0) { privateGetDeclaredFields(true); } // Field[] declaredPublicFields;
4240 if ((flags & RD_DECLARED_INTERFACES ) != 0) { getInterfaces(false); } // Class<?>[] interfaces;
4241 if ((flags & RD_DECLARED_SIMPLE_NAME ) != 0) { getSimpleName(); } // String simpleName;
4242 if ((flags & RD_DECLARED_CANONICAL_NAME) != 0) { getCanonicalName(); } // String canonicalName;
4243 }
4244
4245 // -- }
4246 }