1 /*
2 * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.constant.ClassDesc;
30 import java.lang.constant.ConstantDescs;
31 import java.lang.invoke.TypeDescriptor;
32 import java.lang.invoke.MethodHandles;
33 import java.lang.ref.SoftReference;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.ObjectStreamField;
37 import java.lang.reflect.AnnotatedElement;
38 import java.lang.reflect.AnnotatedType;
39 import java.lang.reflect.AccessFlag;
40 import java.lang.reflect.Array;
41 import java.lang.reflect.Constructor;
42 import java.lang.reflect.Executable;
43 import java.lang.reflect.Field;
44 import java.lang.reflect.GenericArrayType;
45 import java.lang.reflect.GenericDeclaration;
46 import java.lang.reflect.InvocationTargetException;
47 import java.lang.reflect.Member;
48 import java.lang.reflect.Method;
49 import java.lang.reflect.Modifier;
50 import java.lang.reflect.Proxy;
51 import java.lang.reflect.RecordComponent;
52 import java.lang.reflect.Type;
53 import java.lang.reflect.TypeVariable;
54 import java.lang.constant.Constable;
55 import java.net.URL;
56 import java.security.AllPermission;
57 import java.security.Permissions;
58 import java.security.ProtectionDomain;
59 import java.util.ArrayList;
60 import java.util.Arrays;
61 import java.util.Collection;
62 import java.util.HashMap;
63 import java.util.LinkedHashMap;
64 import java.util.LinkedHashSet;
65 import java.util.List;
66 import java.util.Map;
67 import java.util.Objects;
68 import java.util.Optional;
69 import java.util.Set;
70 import java.util.stream.Collectors;
71
72 import jdk.internal.constant.ConstantUtils;
73 import jdk.internal.loader.BootLoader;
74 import jdk.internal.loader.BuiltinClassLoader;
75 import jdk.internal.misc.Unsafe;
76 import jdk.internal.module.Resources;
77 import jdk.internal.reflect.CallerSensitive;
78 import jdk.internal.reflect.CallerSensitiveAdapter;
79 import jdk.internal.reflect.ConstantPool;
80 import jdk.internal.reflect.Reflection;
81 import jdk.internal.reflect.ReflectionFactory;
82 import jdk.internal.vm.annotation.IntrinsicCandidate;
83 import jdk.internal.vm.annotation.Stable;
84
85 import sun.invoke.util.Wrapper;
86 import sun.reflect.generics.factory.CoreReflectionFactory;
87 import sun.reflect.generics.factory.GenericsFactory;
88 import sun.reflect.generics.repository.ClassRepository;
89 import sun.reflect.generics.repository.MethodRepository;
90 import sun.reflect.generics.repository.ConstructorRepository;
91 import sun.reflect.generics.scope.ClassScope;
92 import sun.reflect.annotation.*;
93
94 /**
95 * Instances of the class {@code Class} represent classes and
96 * interfaces in a running Java application. An enum class and a record
97 * class are kinds of class; an annotation interface is a kind of
98 * interface. Every array also belongs to a class that is reflected as
99 * a {@code Class} object that is shared by all arrays with the same
100 * element type and number of dimensions. The primitive Java types
101 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
102 * int}, {@code long}, {@code float}, and {@code double}), and the
103 * keyword {@code void} are also represented as {@code Class} objects.
104 *
105 * <p> {@code Class} has no public constructor. Instead a {@code Class}
106 * object is constructed automatically by the Java Virtual Machine when
107 * a class is derived from the bytes of a {@code class} file through
108 * the invocation of one of the following methods:
109 * <ul>
110 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
111 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
112 * java.lang.invoke.MethodHandles.Lookup::defineClass}
113 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
114 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
115 * </ul>
116 *
117 * <p> The methods of class {@code Class} expose many characteristics of a
118 * class or interface. Most characteristics are derived from the {@code class}
119 * file that the class loader passed to the Java Virtual Machine or
120 * from the {@code class} file passed to {@code Lookup::defineClass}
121 * or {@code Lookup::defineHiddenClass}.
122 * A few characteristics are determined by the class loading environment
123 * at run time, such as the module returned by {@link #getModule() getModule()}.
124 *
125 * <p> The following example uses a {@code Class} object to print the
126 * class name of an object:
127 *
128 * {@snippet lang="java" :
129 * void printClassName(Object obj) {
130 * System.out.println("The class of " + obj +
131 * " is " + obj.getClass().getName());
132 * }}
133 *
134 * It is also possible to get the {@code Class} object for a named
135 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
136 * (JLS {@jls 15.8.2}).
137 * For example:
138 *
139 * {@snippet lang="java" :
140 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
141 * }
142 *
143 * <p> Some methods of class {@code Class} expose whether the declaration of
144 * a class or interface in Java source code was <em>enclosed</em> within
145 * another declaration. Other methods describe how a class or interface
146 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
147 * classes and interfaces, in the same run-time package, that
148 * allow mutual access to their {@code private} members.
149 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
150 * (JVMS {@jvms 4.7.29}).
151 * One nestmate acts as the
152 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
153 * belong to the nest; each of them in turn records it as the nest host.
154 * The classes and interfaces which belong to a nest, including its host, are
155 * determined when
156 * {@code class} files are generated, for example, a Java compiler
157 * will typically record a top-level class as the host of a nest where the
158 * other members are the classes and interfaces whose declarations are
159 * enclosed within the top-level class declaration.
160 *
161 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
162 * A class or interface created by the invocation of
163 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
164 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
165 * class or interface.
166 * All kinds of class, including enum classes and record classes, may be
167 * hidden classes; all kinds of interface, including annotation interfaces,
168 * may be hidden interfaces.
169 *
170 * The {@linkplain #getName() name of a hidden class or interface} is
171 * not a {@linkplain ClassLoader##binary-name binary name},
172 * which means the following:
173 * <ul>
174 * <li>A hidden class or interface cannot be referenced by the constant pools
175 * of other classes and interfaces.
176 * <li>A hidden class or interface cannot be described in
177 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
178 * {@link #describeConstable() Class::describeConstable},
179 * {@link ClassDesc#of(String) ClassDesc::of}, or
180 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
181 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
182 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
183 * </ul>
184 *
185 * A hidden class or interface is never an array class, but may be
186 * the element type of an array. In all other respects, the fact that
187 * a class or interface is hidden has no bearing on the characteristics
188 * exposed by the methods of class {@code Class}.
189 *
190 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
191 *
192 * Conventionally, a Java compiler, starting from a source file for an
193 * implicitly declared class, say {@code HelloWorld.java}, creates a
194 * similarly-named {@code class} file, {@code HelloWorld.class}, where
195 * the class stored in that {@code class} file is named {@code
196 * "HelloWorld"}, matching the base names of the source and {@code
197 * class} files.
198 *
199 * For the {@code Class} object of an implicitly declared class {@code
200 * HelloWorld}, the methods to get the {@linkplain #getName name} and
201 * {@linkplain #getTypeName type name} return results
202 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
203 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
204 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
205 *
206 * @param <T> the type of the class modeled by this {@code Class}
207 * object. For example, the type of {@code String.class} is {@code
208 * Class<String>}. Use {@code Class<?>} if the class being modeled is
209 * unknown.
210 *
211 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
212 * @since 1.0
213 */
214 public final class Class<T> implements java.io.Serializable,
215 GenericDeclaration,
216 Type,
217 AnnotatedElement,
218 TypeDescriptor.OfField<Class<?>>,
219 Constable {
220 private static final int ANNOTATION= 0x00002000;
221 private static final int ENUM = 0x00004000;
222 private static final int SYNTHETIC = 0x00001000;
223
224 private static native void registerNatives();
225 static {
226 runtimeSetup();
227 }
228
229 // Called from JVM when loading an AOT cache
230 private static void runtimeSetup() {
231 registerNatives();
232 }
233
234 /*
235 * Private constructor. Only the Java Virtual Machine creates Class objects.
236 * This constructor is not used and prevents the default constructor being
237 * generated.
238 */
239 private Class(ClassLoader loader, Class<?> arrayComponentType) {
240 // Initialize final field for classLoader. The initialization value of non-null
241 // prevents future JIT optimizations from assuming this final field is null.
242 classLoader = loader;
243 componentType = arrayComponentType;
244 }
245
246 /**
247 * Converts the object to a string. The string representation is the
248 * string "class" or "interface", followed by a space, and then by the
249 * name of the class in the format returned by {@code getName}.
250 * If this {@code Class} object represents a primitive type,
251 * this method returns the name of the primitive type. If
252 * this {@code Class} object represents void this method returns
253 * "void". If this {@code Class} object represents an array type,
254 * this method returns "class " followed by {@code getName}.
255 *
256 * @return a string representation of this {@code Class} object.
257 */
258 public String toString() {
259 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
260 return kind.concat(getName());
261 }
262
263 /**
264 * Returns a string describing this {@code Class}, including
265 * information about modifiers, {@link #isSealed() sealed}/{@code
266 * non-sealed} status, and type parameters.
267 *
268 * The string is formatted as a list of type modifiers, if any,
269 * followed by the kind of type (empty string for primitive types
270 * and {@code class}, {@code enum}, {@code interface},
271 * {@code @interface}, or {@code record} as appropriate), followed
272 * by the type's name, followed by an angle-bracketed
273 * comma-separated list of the type's type parameters, if any,
274 * including informative bounds on the type parameters, if any.
275 *
276 * A space is used to separate modifiers from one another and to
277 * separate any modifiers from the kind of type. The modifiers
278 * occur in canonical order. If there are no type parameters, the
279 * type parameter list is elided.
280 *
281 * For an array type, the string starts with the type name,
282 * followed by an angle-bracketed comma-separated list of the
283 * type's type parameters, if any, followed by a sequence of
284 * {@code []} characters, one set of brackets per dimension of
285 * the array.
286 *
287 * <p>Note that since information about the runtime representation
288 * of a type is being generated, modifiers not present on the
289 * originating source code or illegal on the originating source
290 * code may be present.
291 *
292 * @return a string describing this {@code Class}, including
293 * information about modifiers and type parameters
294 *
295 * @since 1.8
296 */
297 public String toGenericString() {
298 if (isPrimitive()) {
299 return toString();
300 } else {
301 StringBuilder sb = new StringBuilder();
302 Class<?> component = this;
303 int arrayDepth = 0;
304
305 if (isArray()) {
306 do {
307 arrayDepth++;
308 component = component.getComponentType();
309 } while (component.isArray());
310 sb.append(component.getName());
311 } else {
312 // Class modifiers are a superset of interface modifiers
313 int modifiers = getModifiers() & Modifier.classModifiers();
314 if (modifiers != 0) {
315 sb.append(Modifier.toString(modifiers));
316 sb.append(' ');
317 }
318
319 // A class cannot be strictfp and sealed/non-sealed so
320 // it is sufficient to check for sealed-ness after all
321 // modifiers are printed.
322 addSealingInfo(modifiers, sb);
323
324 if (isAnnotation()) {
325 sb.append('@');
326 }
327 if (isInterface()) { // Note: all annotation interfaces are interfaces
328 sb.append("interface");
329 } else {
330 if (isEnum())
331 sb.append("enum");
332 else if (isRecord())
333 sb.append("record");
334 else
335 sb.append("class");
336 }
337 sb.append(' ');
338 sb.append(getName());
339 }
340
341 TypeVariable<?>[] typeparms = component.getTypeParameters();
342 if (typeparms.length > 0) {
343 sb.append(Arrays.stream(typeparms)
344 .map(Class::typeVarBounds)
345 .collect(Collectors.joining(",", "<", ">")));
346 }
347
348 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
349
350 return sb.toString();
351 }
352 }
353
354 private void addSealingInfo(int modifiers, StringBuilder sb) {
355 // A class can be final XOR sealed XOR non-sealed.
356 if (Modifier.isFinal(modifiers)) {
357 return; // no-op
358 } else {
359 if (isSealed()) {
360 sb.append("sealed ");
361 return;
362 } else {
363 // Check for sealed ancestor, which implies this class
364 // is non-sealed.
365 if (hasSealedAncestor(this)) {
366 sb.append("non-sealed ");
367 }
368 }
369 }
370 }
371
372 private boolean hasSealedAncestor(Class<?> clazz) {
373 // From JLS 8.1.1.2:
374 // "It is a compile-time error if a class has a sealed direct
375 // superclass or a sealed direct superinterface, and is not
376 // declared final, sealed, or non-sealed either explicitly or
377 // implicitly.
378 // Thus, an effect of the sealed keyword is to force all
379 // direct subclasses to explicitly declare whether they are
380 // final, sealed, or non-sealed. This avoids accidentally
381 // exposing a sealed class hierarchy to unwanted subclassing."
382
383 // Therefore, will just check direct superclass and
384 // superinterfaces.
385 var superclass = clazz.getSuperclass();
386 if (superclass != null && superclass.isSealed()) {
387 return true;
388 }
389 for (var superinterface : clazz.getInterfaces()) {
390 if (superinterface.isSealed()) {
391 return true;
392 }
393 }
394 return false;
395 }
396
397 static String typeVarBounds(TypeVariable<?> typeVar) {
398 Type[] bounds = typeVar.getBounds();
399 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
400 return typeVar.getName();
401 } else {
402 return typeVar.getName() + " extends " +
403 Arrays.stream(bounds)
404 .map(Type::getTypeName)
405 .collect(Collectors.joining(" & "));
406 }
407 }
408
409 /**
410 * Returns the {@code Class} object associated with the class or
411 * interface with the given string name. Invoking this method is
412 * equivalent to:
413 *
414 * {@snippet lang="java" :
415 * Class.forName(className, true, currentLoader)
416 * }
417 *
418 * where {@code currentLoader} denotes the defining class loader of
419 * the current class.
420 *
421 * <p> For example, the following code fragment returns the
422 * runtime {@code Class} object for the class named
423 * {@code java.lang.Thread}:
424 *
425 * {@snippet lang="java" :
426 * Class<?> t = Class.forName("java.lang.Thread");
427 * }
428 * <p>
429 * A call to {@code forName("X")} causes the class named
430 * {@code X} to be initialized.
431 *
432 * <p>
433 * In cases where this method is called from a context where there is no
434 * caller frame on the stack (e.g. when called directly from a JNI
435 * attached thread), the system class loader is used.
436 *
437 * @param className the {@linkplain ClassLoader##binary-name binary name}
438 * of the class or the string representing an array type
439 * @return the {@code Class} object for the class with the
440 * specified name.
441 * @throws LinkageError if the linkage fails
442 * @throws ExceptionInInitializerError if the initialization provoked
443 * by this method fails
444 * @throws ClassNotFoundException if the class cannot be located
445 *
446 * @jls 12.2 Loading of Classes and Interfaces
447 * @jls 12.3 Linking of Classes and Interfaces
448 * @jls 12.4 Initialization of Classes and Interfaces
449 */
450 @CallerSensitive
451 public static Class<?> forName(String className)
452 throws ClassNotFoundException {
453 Class<?> caller = Reflection.getCallerClass();
454 return forName(className, caller);
455 }
456
457 // Caller-sensitive adapter method for reflective invocation
458 @CallerSensitiveAdapter
459 private static Class<?> forName(String className, Class<?> caller)
460 throws ClassNotFoundException {
461 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
462 : ClassLoader.getClassLoader(caller);
463 if (loader instanceof BuiltinClassLoader bcl) {
464 if (bcl.usePositiveCache) {
465 Class<?> result = bcl.checkPositiveLookupCache(className);
466 if (result != null) {
467 return result;
468 }
469 }
470 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(className)) {
471 throw new ClassNotFoundException(className);
472 }
473 }
474 return forName0(className, true, loader, caller);
475 }
476
477 /**
478 * Returns the {@code Class} object associated with the class or
479 * interface with the given string name, using the given class loader.
480 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
481 * this method attempts to locate and load the class or interface. The specified
482 * class loader is used to load the class or interface. If the parameter
483 * {@code loader} is {@code null}, the class is loaded through the bootstrap
484 * class loader. The class is initialized only if the
485 * {@code initialize} parameter is {@code true} and if it has
486 * not been initialized earlier.
487 *
488 * <p> This method cannot be used to obtain any of the {@code Class} objects
489 * representing primitive types or void, hidden classes or interfaces,
490 * or array classes whose element type is a hidden class or interface.
491 * If {@code name} denotes a primitive type or void, for example {@code I},
492 * an attempt will be made to locate a user-defined class in the unnamed package
493 * whose name is {@code I} instead.
494 * To obtain a {@code Class} object for a named primitive type
495 * such as {@code int} or {@code long} use {@link
496 * #forPrimitiveName(String)}.
497 *
498 * <p> To obtain the {@code Class} object associated with an array class,
499 * the name consists of one or more {@code '['} representing the depth
500 * of the array nesting, followed by the element type as encoded in
501 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
502 *
503 * <p> Examples:
504 * {@snippet lang="java" :
505 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
506 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
507 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
508 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
509 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
510 * }
511 *
512 * <p> A call to {@code getName()} on the {@code Class} object returned
513 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
514 *
515 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
516 * named <i>N</i> to be loaded but not initialized regardless of the value
517 * of the {@code initialize} parameter.
518 *
519 * @apiNote
520 * This method throws errors related to loading, linking or initializing
521 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
522 * <cite>The Java Language Specification</cite>.
523 * In addition, this method does not check whether the requested class
524 * is accessible to its caller.
525 *
526 * @param name the {@linkplain ClassLoader##binary-name binary name}
527 * of the class or the string representing an array class
528 *
529 * @param initialize if {@code true} the class will be initialized
530 * (which implies linking). See Section {@jls
531 * 12.4} of <cite>The Java Language
532 * Specification</cite>.
533 * @param loader class loader from which the class must be loaded
534 * @return class object representing the desired class
535 *
536 * @throws LinkageError if the linkage fails
537 * @throws ExceptionInInitializerError if the initialization provoked
538 * by this method fails
539 * @throws ClassNotFoundException if the class cannot be located by
540 * the specified class loader
541 *
542 * @see java.lang.Class#forName(String)
543 * @see java.lang.ClassLoader
544 *
545 * @jls 12.2 Loading of Classes and Interfaces
546 * @jls 12.3 Linking of Classes and Interfaces
547 * @jls 12.4 Initialization of Classes and Interfaces
548 * @jls 13.1 The Form of a Binary
549 * @since 1.2
550 */
551 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
552 throws ClassNotFoundException
553 {
554 if (loader instanceof BuiltinClassLoader bcl) {
555 if (bcl.usePositiveCache) {
556 Class<?> result = bcl.checkPositiveLookupCache(name);
557 if (result != null) {
558 return result;
559 }
560 }
561 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(name)) {
562 throw new ClassNotFoundException(name);
563 }
564 }
565 return forName0(name, initialize, loader, null);
566 }
567
568 /** Called after security check for system loader access checks have been made. */
569 private static native Class<?> forName0(String name, boolean initialize,
570 ClassLoader loader,
571 Class<?> caller)
572 throws ClassNotFoundException;
573
574
575 /**
576 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
577 * binary name} in the given module.
578 *
579 * <p> This method attempts to locate and load the class or interface.
580 * It does not link the class, and does not run the class initializer.
581 * If the class is not found, this method returns {@code null}. </p>
582 *
583 * <p> If the class loader of the given module defines other modules and
584 * the given name is a class defined in a different module, this method
585 * returns {@code null} after the class is loaded. </p>
586 *
587 * <p> This method does not check whether the requested class is
588 * accessible to its caller. </p>
589 *
590 * @apiNote
591 * This method does not support loading of array types, unlike
592 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
593 * a binary name. This method returns {@code null} on failure rather than
594 * throwing a {@link ClassNotFoundException}, as is done by
595 * the {@link #forName(String, boolean, ClassLoader)} method.
596 *
597 * @param module A module
598 * @param name The {@linkplain ClassLoader##binary-name binary name}
599 * of the class
600 * @return {@code Class} object of the given name defined in the given module;
601 * {@code null} if not found.
602 *
603 * @throws NullPointerException if the given module or name is {@code null}
604 *
605 * @throws LinkageError if the linkage fails
606 *
607 * @jls 12.2 Loading of Classes and Interfaces
608 * @jls 12.3 Linking of Classes and Interfaces
609 * @since 9
610 */
611 public static Class<?> forName(Module module, String name) {
612 Objects.requireNonNull(module);
613 Objects.requireNonNull(name);
614
615 ClassLoader cl = module.getClassLoader();
616 if (cl != null) {
617 return cl.loadClass(module, name);
618 } else {
619 return BootLoader.loadClass(module, name);
620 }
621 }
622
623 /**
624 * {@return the {@code Class} object associated with the
625 * {@linkplain #isPrimitive() primitive type} of the given name}
626 * If the argument is not the name of a primitive type, {@code
627 * null} is returned.
628 *
629 * @param primitiveName the name of the primitive type to find
630 *
631 * @throws NullPointerException if the argument is {@code null}
632 *
633 * @jls 4.2 Primitive Types and Values
634 * @jls 15.8.2 Class Literals
635 * @since 22
636 */
637 public static Class<?> forPrimitiveName(String primitiveName) {
638 return switch(primitiveName) {
639 // Integral types
640 case "int" -> int.class;
641 case "long" -> long.class;
642 case "short" -> short.class;
643 case "char" -> char.class;
644 case "byte" -> byte.class;
645
646 // Floating-point types
647 case "float" -> float.class;
648 case "double" -> double.class;
649
650 // Other types
651 case "boolean" -> boolean.class;
652 case "void" -> void.class;
653
654 default -> null;
655 };
656 }
657
658 /**
659 * Creates a new instance of the class represented by this {@code Class}
660 * object. The class is instantiated as if by a {@code new}
661 * expression with an empty argument list. The class is initialized if it
662 * has not already been initialized.
663 *
664 * @deprecated This method propagates any exception thrown by the
665 * nullary constructor, including a checked exception. Use of
666 * this method effectively bypasses the compile-time exception
667 * checking that would otherwise be performed by the compiler.
668 * The {@link
669 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
670 * Constructor.newInstance} method avoids this problem by wrapping
671 * any exception thrown by the constructor in a (checked) {@link
672 * java.lang.reflect.InvocationTargetException}.
673 *
674 * <p>The call
675 *
676 * {@snippet lang="java" :
677 * clazz.newInstance()
678 * }
679 *
680 * can be replaced by
681 *
682 * {@snippet lang="java" :
683 * clazz.getDeclaredConstructor().newInstance()
684 * }
685 *
686 * The latter sequence of calls is inferred to be able to throw
687 * the additional exception types {@link
688 * InvocationTargetException} and {@link
689 * NoSuchMethodException}. Both of these exception types are
690 * subclasses of {@link ReflectiveOperationException}.
691 *
692 * @return a newly allocated instance of the class represented by this
693 * object.
694 * @throws IllegalAccessException if the class or its nullary
695 * constructor is not accessible.
696 * @throws InstantiationException
697 * if this {@code Class} represents an abstract class,
698 * an interface, an array class, a primitive type, or void;
699 * or if the class has no nullary constructor;
700 * or if the instantiation fails for some other reason.
701 * @throws ExceptionInInitializerError if the initialization
702 * provoked by this method fails.
703 */
704 @CallerSensitive
705 @Deprecated(since="9")
706 public T newInstance()
707 throws InstantiationException, IllegalAccessException
708 {
709 // Constructor lookup
710 Constructor<T> tmpConstructor = cachedConstructor;
711 if (tmpConstructor == null) {
712 if (this == Class.class) {
713 throw new IllegalAccessException(
714 "Can not call newInstance() on the Class for java.lang.Class"
715 );
716 }
717 try {
718 Class<?>[] empty = {};
719 final Constructor<T> c = getReflectionFactory().copyConstructor(
720 getConstructor0(empty, Member.DECLARED));
721 // Disable accessibility checks on the constructor
722 // access check is done with the true caller
723 c.setAccessible(true);
724 cachedConstructor = tmpConstructor = c;
725 } catch (NoSuchMethodException e) {
726 throw (InstantiationException)
727 new InstantiationException(getName()).initCause(e);
728 }
729 }
730
731 try {
732 Class<?> caller = Reflection.getCallerClass();
733 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
734 } catch (InvocationTargetException e) {
735 Unsafe.getUnsafe().throwException(e.getTargetException());
736 // Not reached
737 return null;
738 }
739 }
740
741 private transient volatile Constructor<T> cachedConstructor;
742
743 /**
744 * Determines if the specified {@code Object} is assignment-compatible
745 * with the object represented by this {@code Class}. This method is
746 * the dynamic equivalent of the Java language {@code instanceof}
747 * operator. The method returns {@code true} if the specified
748 * {@code Object} argument is non-null and can be cast to the
749 * reference type represented by this {@code Class} object without
750 * raising a {@code ClassCastException.} It returns {@code false}
751 * otherwise.
752 *
753 * <p> Specifically, if this {@code Class} object represents a
754 * declared class, this method returns {@code true} if the specified
755 * {@code Object} argument is an instance of the represented class (or
756 * of any of its subclasses); it returns {@code false} otherwise. If
757 * this {@code Class} object represents an array class, this method
758 * returns {@code true} if the specified {@code Object} argument
759 * can be converted to an object of the array class by an identity
760 * conversion or by a widening reference conversion; it returns
761 * {@code false} otherwise. If this {@code Class} object
762 * represents an interface, this method returns {@code true} if the
763 * class or any superclass of the specified {@code Object} argument
764 * implements this interface; it returns {@code false} otherwise. If
765 * this {@code Class} object represents a primitive type, this method
766 * returns {@code false}.
767 *
768 * @param obj the object to check
769 * @return true if {@code obj} is an instance of this class
770 *
771 * @since 1.1
772 */
773 @IntrinsicCandidate
774 public native boolean isInstance(Object obj);
775
776
777 /**
778 * Determines if the class or interface represented by this
779 * {@code Class} object is either the same as, or is a superclass or
780 * superinterface of, the class or interface represented by the specified
781 * {@code Class} parameter. It returns {@code true} if so;
782 * otherwise it returns {@code false}. If this {@code Class}
783 * object represents a primitive type, this method returns
784 * {@code true} if the specified {@code Class} parameter is
785 * exactly this {@code Class} object; otherwise it returns
786 * {@code false}.
787 *
788 * <p> Specifically, this method tests whether the type represented by the
789 * specified {@code Class} parameter can be converted to the type
790 * represented by this {@code Class} object via an identity conversion
791 * or via a widening reference conversion. See <cite>The Java Language
792 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
793 * for details.
794 *
795 * @param cls the {@code Class} object to be checked
796 * @return the {@code boolean} value indicating whether objects of the
797 * type {@code cls} can be assigned to objects of this class
798 * @throws NullPointerException if the specified Class parameter is
799 * null.
800 * @since 1.1
801 */
802 @IntrinsicCandidate
803 public native boolean isAssignableFrom(Class<?> cls);
804
805
806 /**
807 * Determines if this {@code Class} object represents an
808 * interface type.
809 *
810 * @return {@code true} if this {@code Class} object represents an interface;
811 * {@code false} otherwise.
812 */
813 @IntrinsicCandidate
814 public native boolean isInterface();
815
816
817 /**
818 * Determines if this {@code Class} object represents an array class.
819 *
820 * @return {@code true} if this {@code Class} object represents an array class;
821 * {@code false} otherwise.
822 * @since 1.1
823 */
824 @IntrinsicCandidate
825 public native boolean isArray();
826
827
828 /**
829 * Determines if this {@code Class} object represents a primitive
830 * type or void.
831 *
832 * <p> There are nine predefined {@code Class} objects to
833 * represent the eight primitive types and void. These are
834 * created by the Java Virtual Machine, and have the same
835 * {@linkplain #getName() names} as the primitive types that they
836 * represent, namely {@code boolean}, {@code byte}, {@code char},
837 * {@code short}, {@code int}, {@code long}, {@code float}, and
838 * {@code double}.
839 *
840 * <p>No other class objects are considered primitive.
841 *
842 * @apiNote
843 * A {@code Class} object represented by a primitive type can be
844 * accessed via the {@code TYPE} public static final variables
845 * defined in the primitive wrapper classes such as {@link
846 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
847 * language, the objects may be referred to by a class literal
848 * expression such as {@code int.class}. The {@code Class} object
849 * for void can be expressed as {@code void.class} or {@link
850 * java.lang.Void#TYPE Void.TYPE}.
851 *
852 * @return true if and only if this class represents a primitive type
853 *
854 * @see java.lang.Boolean#TYPE
855 * @see java.lang.Character#TYPE
856 * @see java.lang.Byte#TYPE
857 * @see java.lang.Short#TYPE
858 * @see java.lang.Integer#TYPE
859 * @see java.lang.Long#TYPE
860 * @see java.lang.Float#TYPE
861 * @see java.lang.Double#TYPE
862 * @see java.lang.Void#TYPE
863 * @since 1.1
864 * @jls 15.8.2 Class Literals
865 */
866 @IntrinsicCandidate
867 public native boolean isPrimitive();
868
869 /**
870 * Returns true if this {@code Class} object represents an annotation
871 * interface. Note that if this method returns true, {@link #isInterface()}
872 * would also return true, as all annotation interfaces are also interfaces.
873 *
874 * @return {@code true} if this {@code Class} object represents an annotation
875 * interface; {@code false} otherwise
876 * @since 1.5
877 */
878 public boolean isAnnotation() {
879 return (getModifiers() & ANNOTATION) != 0;
880 }
881
882 /**
883 *{@return {@code true} if and only if this class has the synthetic modifier
884 * bit set}
885 *
886 * @jls 13.1 The Form of a Binary
887 * @jvms 4.1 The {@code ClassFile} Structure
888 * @see <a
889 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
890 * programming language and JVM modeling in core reflection</a>
891 * @since 1.5
892 */
893 public boolean isSynthetic() {
894 return (getModifiers() & SYNTHETIC) != 0;
895 }
896
897 /**
898 * Returns the name of the entity (class, interface, array class,
899 * primitive type, or void) represented by this {@code Class} object.
900 *
901 * <p> If this {@code Class} object represents a class or interface,
902 * not an array class, then:
903 * <ul>
904 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
905 * then the {@linkplain ClassLoader##binary-name binary name}
906 * of the class or interface is returned.
907 * <li> If the class or interface is hidden, then the result is a string
908 * of the form: {@code N + '/' + <suffix>}
909 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
910 * indicated by the {@code class} file passed to
911 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
912 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
913 * </ul>
914 *
915 * <p> If this {@code Class} object represents an array class, then
916 * the result is a string consisting of one or more '{@code [}' characters
917 * representing the depth of the array nesting, followed by the element
918 * type as encoded using the following table:
919 *
920 * <blockquote><table class="striped" id="nameFormat">
921 * <caption style="display:none">Element types and encodings</caption>
922 * <thead>
923 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
924 * </thead>
925 * <tbody style="text-align:left">
926 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
927 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
928 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
929 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
930 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
931 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
932 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
933 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
934 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
935 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
936 * </tbody>
937 * </table></blockquote>
938 *
939 * <p> If this {@code Class} object represents a primitive type or {@code void},
940 * then the result is a string with the same spelling as the Java language
941 * keyword which corresponds to the primitive type or {@code void}.
942 *
943 * <p> Examples:
944 * <blockquote><pre>
945 * String.class.getName()
946 * returns "java.lang.String"
947 * Character.UnicodeBlock.class.getName()
948 * returns "java.lang.Character$UnicodeBlock"
949 * byte.class.getName()
950 * returns "byte"
951 * (new Object[3]).getClass().getName()
952 * returns "[Ljava.lang.Object;"
953 * (new int[3][4][5][6][7][8][9]).getClass().getName()
954 * returns "[[[[[[[I"
955 * </pre></blockquote>
956 *
957 * @apiNote
958 * Distinct class objects can have the same name but different class loaders.
959 *
960 * @return the name of the class, interface, or other entity
961 * represented by this {@code Class} object.
962 * @jls 13.1 The Form of a Binary
963 */
964 public String getName() {
965 String name = this.name;
966 return name != null ? name : initClassName();
967 }
968
969 // Cache the name to reduce the number of calls into the VM.
970 // This field would be set by VM itself during initClassName call.
971 private transient String name;
972 private native String initClassName();
973
974 /**
975 * Returns the class loader for the class. Some implementations may use
976 * null to represent the bootstrap class loader. This method will return
977 * null in such implementations if this class was loaded by the bootstrap
978 * class loader.
979 *
980 * <p>If this {@code Class} object
981 * represents a primitive type or void, null is returned.
982 *
983 * @return the class loader that loaded the class or interface
984 * represented by this {@code Class} object.
985 * @see java.lang.ClassLoader
986 */
987 public ClassLoader getClassLoader() {
988 return classLoader;
989 }
990
991 // Package-private to allow ClassLoader access
992 ClassLoader getClassLoader0() { return classLoader; }
993
994 /**
995 * Returns the module that this class or interface is a member of.
996 *
997 * If this class represents an array type then this method returns the
998 * {@code Module} for the element type. If this class represents a
999 * primitive type or void, then the {@code Module} object for the
1000 * {@code java.base} module is returned.
1001 *
1002 * If this class is in an unnamed module then the {@linkplain
1003 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1004 * loader for this class is returned.
1005 *
1006 * @return the module that this class or interface is a member of
1007 *
1008 * @since 9
1009 */
1010 public Module getModule() {
1011 return module;
1012 }
1013
1014 // set by VM
1015 @Stable
1016 private transient Module module;
1017
1018 // Initialized in JVM not by private constructor
1019 // This field is filtered from reflection access, i.e. getDeclaredField
1020 // will throw NoSuchFieldException
1021 private final ClassLoader classLoader;
1022
1023 private transient Object classData; // Set by VM
1024 private transient Object[] signers; // Read by VM, mutable
1025
1026 // package-private
1027 Object getClassData() {
1028 return classData;
1029 }
1030
1031 /**
1032 * Returns an array of {@code TypeVariable} objects that represent the
1033 * type variables declared by the generic declaration represented by this
1034 * {@code GenericDeclaration} object, in declaration order. Returns an
1035 * array of length 0 if the underlying generic declaration declares no type
1036 * variables.
1037 *
1038 * @return an array of {@code TypeVariable} objects that represent
1039 * the type variables declared by this generic declaration
1040 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1041 * signature of this generic declaration does not conform to
1042 * the format specified in section {@jvms 4.7.9} of
1043 * <cite>The Java Virtual Machine Specification</cite>
1044 * @since 1.5
1045 */
1046 @SuppressWarnings("unchecked")
1047 public TypeVariable<Class<T>>[] getTypeParameters() {
1048 ClassRepository info = getGenericInfo();
1049 if (info != null)
1050 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1051 else
1052 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1053 }
1054
1055
1056 /**
1057 * Returns the {@code Class} representing the direct superclass of the
1058 * entity (class, interface, primitive type or void) represented by
1059 * this {@code Class}. If this {@code Class} represents either the
1060 * {@code Object} class, an interface, a primitive type, or void, then
1061 * null is returned. If this {@code Class} object represents an array class
1062 * then the {@code Class} object representing the {@code Object} class is
1063 * returned.
1064 *
1065 * @return the direct superclass of the class represented by this {@code Class} object
1066 */
1067 @IntrinsicCandidate
1068 public native Class<? super T> getSuperclass();
1069
1070
1071 /**
1072 * Returns the {@code Type} representing the direct superclass of
1073 * the entity (class, interface, primitive type or void) represented by
1074 * this {@code Class} object.
1075 *
1076 * <p>If the superclass is a parameterized type, the {@code Type}
1077 * object returned must accurately reflect the actual type
1078 * arguments used in the source code. The parameterized type
1079 * representing the superclass is created if it had not been
1080 * created before. See the declaration of {@link
1081 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1082 * semantics of the creation process for parameterized types. If
1083 * this {@code Class} object represents either the {@code Object}
1084 * class, an interface, a primitive type, or void, then null is
1085 * returned. If this {@code Class} object represents an array class
1086 * then the {@code Class} object representing the {@code Object} class is
1087 * returned.
1088 *
1089 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1090 * class signature does not conform to the format specified in
1091 * section {@jvms 4.7.9} of <cite>The Java Virtual
1092 * Machine Specification</cite>
1093 * @throws TypeNotPresentException if the generic superclass
1094 * refers to a non-existent type declaration
1095 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1096 * generic superclass refers to a parameterized type that cannot be
1097 * instantiated for any reason
1098 * @return the direct superclass of the class represented by this {@code Class} object
1099 * @since 1.5
1100 */
1101 public Type getGenericSuperclass() {
1102 ClassRepository info = getGenericInfo();
1103 if (info == null) {
1104 return getSuperclass();
1105 }
1106
1107 // Historical irregularity:
1108 // Generic signature marks interfaces with superclass = Object
1109 // but this API returns null for interfaces
1110 if (isInterface()) {
1111 return null;
1112 }
1113
1114 return info.getSuperclass();
1115 }
1116
1117 /**
1118 * Gets the package of this class.
1119 *
1120 * <p>If this class represents an array type, a primitive type or void,
1121 * this method returns {@code null}.
1122 *
1123 * @return the package of this class.
1124 */
1125 public Package getPackage() {
1126 if (isPrimitive() || isArray()) {
1127 return null;
1128 }
1129 ClassLoader cl = classLoader;
1130 return cl != null ? cl.definePackage(this)
1131 : BootLoader.definePackage(this);
1132 }
1133
1134 /**
1135 * Returns the fully qualified package name.
1136 *
1137 * <p> If this class is a top level class, then this method returns the fully
1138 * qualified name of the package that the class is a member of, or the
1139 * empty string if the class is in an unnamed package.
1140 *
1141 * <p> If this class is a member class, then this method is equivalent to
1142 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1143 * enclosing class}.
1144 *
1145 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1146 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1147 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1148 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1149 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1150 *
1151 * <p> If this class represents an array type then this method returns the
1152 * package name of the element type. If this class represents a primitive
1153 * type or void then the package name "{@code java.lang}" is returned.
1154 *
1155 * @return the fully qualified package name
1156 *
1157 * @since 9
1158 * @jls 6.7 Fully Qualified Names and Canonical Names
1159 */
1160 public String getPackageName() {
1161 String pn = this.packageName;
1162 if (pn == null) {
1163 Class<?> c = isArray() ? elementType() : this;
1164 if (c.isPrimitive()) {
1165 pn = "java.lang";
1166 } else {
1167 String cn = c.getName();
1168 int dot = cn.lastIndexOf('.');
1169 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1170 }
1171 this.packageName = pn;
1172 }
1173 return pn;
1174 }
1175
1176 // cached package name
1177 private transient String packageName;
1178
1179 /**
1180 * Returns the interfaces directly implemented by the class or interface
1181 * represented by this {@code Class} object.
1182 *
1183 * <p>If this {@code Class} object represents a class, the return value is an array
1184 * containing objects representing all interfaces directly implemented by
1185 * the class. The order of the interface objects in the array corresponds
1186 * to the order of the interface names in the {@code implements} clause of
1187 * the declaration of the class represented by this {@code Class} object. For example,
1188 * given the declaration:
1189 * <blockquote>
1190 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1191 * </blockquote>
1192 * suppose the value of {@code s} is an instance of
1193 * {@code Shimmer}; the value of the expression:
1194 * <blockquote>
1195 * {@code s.getClass().getInterfaces()[0]}
1196 * </blockquote>
1197 * is the {@code Class} object that represents interface
1198 * {@code FloorWax}; and the value of:
1199 * <blockquote>
1200 * {@code s.getClass().getInterfaces()[1]}
1201 * </blockquote>
1202 * is the {@code Class} object that represents interface
1203 * {@code DessertTopping}.
1204 *
1205 * <p>If this {@code Class} object represents an interface, the array contains objects
1206 * representing all interfaces directly extended by the interface. The
1207 * order of the interface objects in the array corresponds to the order of
1208 * the interface names in the {@code extends} clause of the declaration of
1209 * the interface represented by this {@code Class} object.
1210 *
1211 * <p>If this {@code Class} object represents a class or interface that implements no
1212 * interfaces, the method returns an array of length 0.
1213 *
1214 * <p>If this {@code Class} object represents a primitive type or void, the method
1215 * returns an array of length 0.
1216 *
1217 * <p>If this {@code Class} object represents an array type, the
1218 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1219 * returned in that order.
1220 *
1221 * @return an array of interfaces directly implemented by this class
1222 */
1223 public Class<?>[] getInterfaces() {
1224 // defensively copy before handing over to user code
1225 return getInterfaces(true);
1226 }
1227
1228 private Class<?>[] getInterfaces(boolean cloneArray) {
1229 ReflectionData<T> rd = reflectionData();
1230 Class<?>[] interfaces = rd.interfaces;
1231 if (interfaces == null) {
1232 interfaces = getInterfaces0();
1233 rd.interfaces = interfaces;
1234 }
1235 // defensively copy if requested
1236 return cloneArray ? interfaces.clone() : interfaces;
1237 }
1238
1239 private native Class<?>[] getInterfaces0();
1240
1241 /**
1242 * Returns the {@code Type}s representing the interfaces
1243 * directly implemented by the class or interface represented by
1244 * this {@code Class} object.
1245 *
1246 * <p>If a superinterface is a parameterized type, the
1247 * {@code Type} object returned for it must accurately reflect
1248 * the actual type arguments used in the source code. The
1249 * parameterized type representing each superinterface is created
1250 * if it had not been created before. See the declaration of
1251 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1252 * for the semantics of the creation process for parameterized
1253 * types.
1254 *
1255 * <p>If this {@code Class} object represents a class, the return value is an array
1256 * containing objects representing all interfaces directly implemented by
1257 * the class. The order of the interface objects in the array corresponds
1258 * to the order of the interface names in the {@code implements} clause of
1259 * the declaration of the class represented by this {@code Class} object.
1260 *
1261 * <p>If this {@code Class} object represents an interface, the array contains objects
1262 * representing all interfaces directly extended by the interface. The
1263 * order of the interface objects in the array corresponds to the order of
1264 * the interface names in the {@code extends} clause of the declaration of
1265 * the interface represented by this {@code Class} object.
1266 *
1267 * <p>If this {@code Class} object represents a class or interface that implements no
1268 * interfaces, the method returns an array of length 0.
1269 *
1270 * <p>If this {@code Class} object represents a primitive type or void, the method
1271 * returns an array of length 0.
1272 *
1273 * <p>If this {@code Class} object represents an array type, the
1274 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1275 * returned in that order.
1276 *
1277 * @throws java.lang.reflect.GenericSignatureFormatError
1278 * if the generic class signature does not conform to the
1279 * format specified in section {@jvms 4.7.9} of <cite>The
1280 * Java Virtual Machine Specification</cite>
1281 * @throws TypeNotPresentException if any of the generic
1282 * superinterfaces refers to a non-existent type declaration
1283 * @throws java.lang.reflect.MalformedParameterizedTypeException
1284 * if any of the generic superinterfaces refer to a parameterized
1285 * type that cannot be instantiated for any reason
1286 * @return an array of interfaces directly implemented by this class
1287 * @since 1.5
1288 */
1289 public Type[] getGenericInterfaces() {
1290 ClassRepository info = getGenericInfo();
1291 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1292 }
1293
1294
1295 /**
1296 * Returns the {@code Class} representing the component type of an
1297 * array. If this class does not represent an array class this method
1298 * returns null.
1299 *
1300 * @return the {@code Class} representing the component type of this
1301 * class if this class is an array
1302 * @see java.lang.reflect.Array
1303 * @since 1.1
1304 */
1305 public Class<?> getComponentType() {
1306 // Only return for array types. Storage may be reused for Class for instance types.
1307 if (isArray()) {
1308 return componentType;
1309 } else {
1310 return null;
1311 }
1312 }
1313
1314 private final Class<?> componentType;
1315
1316 /*
1317 * Returns the {@code Class} representing the element type of an array class.
1318 * If this class does not represent an array class, then this method returns
1319 * {@code null}.
1320 */
1321 private Class<?> elementType() {
1322 if (!isArray()) return null;
1323
1324 Class<?> c = this;
1325 while (c.isArray()) {
1326 c = c.getComponentType();
1327 }
1328 return c;
1329 }
1330
1331 /**
1332 * Returns the Java language modifiers for this class or interface, encoded
1333 * in an integer. The modifiers consist of the Java Virtual Machine's
1334 * constants for {@code public}, {@code protected},
1335 * {@code private}, {@code final}, {@code static},
1336 * {@code abstract} and {@code interface}; they should be decoded
1337 * using the methods of class {@code Modifier}.
1338 *
1339 * <p> If the underlying class is an array class:
1340 * <ul>
1341 * <li> its {@code public}, {@code private} and {@code protected}
1342 * modifiers are the same as those of its component type
1343 * <li> its {@code abstract} and {@code final} modifiers are always
1344 * {@code true}
1345 * <li> its interface modifier is always {@code false}, even when
1346 * the component type is an interface
1347 * </ul>
1348 * If this {@code Class} object represents a primitive type or
1349 * void, its {@code public}, {@code abstract}, and {@code final}
1350 * modifiers are always {@code true}.
1351 * For {@code Class} objects representing void, primitive types, and
1352 * arrays, the values of other modifiers are {@code false} other
1353 * than as specified above.
1354 *
1355 * <p> The modifier encodings are defined in section {@jvms 4.1}
1356 * of <cite>The Java Virtual Machine Specification</cite>.
1357 *
1358 * @return the {@code int} representing the modifiers for this class
1359 * @see java.lang.reflect.Modifier
1360 * @see #accessFlags()
1361 * @see <a
1362 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1363 * programming language and JVM modeling in core reflection</a>
1364 * @since 1.1
1365 * @jls 8.1.1 Class Modifiers
1366 * @jls 9.1.1 Interface Modifiers
1367 * @jvms 4.1 The {@code ClassFile} Structure
1368 */
1369 @IntrinsicCandidate
1370 public native int getModifiers();
1371
1372 /**
1373 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1374 * flags} for this class, possibly empty}
1375 *
1376 * <p> If the underlying class is an array class:
1377 * <ul>
1378 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1379 * access flags are the same as those of its component type
1380 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1381 * <li> its {@code INTERFACE} flag is absent, even when the
1382 * component type is an interface
1383 * </ul>
1384 * If this {@code Class} object represents a primitive type or
1385 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1386 * {@code FINAL}.
1387 * For {@code Class} objects representing void, primitive types, and
1388 * arrays, access flags are absent other than as specified above.
1389 *
1390 * @see #getModifiers()
1391 * @jvms 4.1 The ClassFile Structure
1392 * @jvms 4.7.6 The InnerClasses Attribute
1393 * @since 20
1394 */
1395 public Set<AccessFlag> accessFlags() {
1396 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1397 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1398 // and STATIC, which are not allowed on Location.CLASS.
1399 // Use getClassAccessFlagsRaw to expose SUPER status.
1400 var location = (isMemberClass() || isLocalClass() ||
1401 isAnonymousClass() || isArray()) ?
1402 AccessFlag.Location.INNER_CLASS :
1403 AccessFlag.Location.CLASS;
1404 return AccessFlag.maskToAccessFlags((location == AccessFlag.Location.CLASS) ?
1405 getClassAccessFlagsRaw() :
1406 getModifiers(),
1407 location);
1408 }
1409
1410 /**
1411 * Gets the signers of this class.
1412 *
1413 * @return the signers of this class, or null if there are no signers. In
1414 * particular, this method returns null if this {@code Class} object represents
1415 * a primitive type or void.
1416 * @since 1.1
1417 */
1418 public Object[] getSigners() {
1419 var signers = this.signers;
1420 return signers == null ? null : signers.clone();
1421 }
1422
1423 /**
1424 * Set the signers of this class.
1425 */
1426 void setSigners(Object[] signers) {
1427 if (!isPrimitive() && !isArray()) {
1428 this.signers = signers;
1429 }
1430 }
1431
1432 /**
1433 * If this {@code Class} object represents a local or anonymous
1434 * class within a method, returns a {@link
1435 * java.lang.reflect.Method Method} object representing the
1436 * immediately enclosing method of the underlying class. Returns
1437 * {@code null} otherwise.
1438 *
1439 * In particular, this method returns {@code null} if the underlying
1440 * class is a local or anonymous class immediately enclosed by a class or
1441 * interface declaration, instance initializer or static initializer.
1442 *
1443 * @return the immediately enclosing method of the underlying class, if
1444 * that class is a local or anonymous class; otherwise {@code null}.
1445 *
1446 * @since 1.5
1447 */
1448 public Method getEnclosingMethod() {
1449 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1450
1451 if (enclosingInfo == null)
1452 return null;
1453 else {
1454 if (!enclosingInfo.isMethod())
1455 return null;
1456
1457 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1458 getFactory());
1459 Class<?> returnType = toClass(typeInfo.getReturnType());
1460 Type [] parameterTypes = typeInfo.getParameterTypes();
1461 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1462
1463 // Convert Types to Classes; returned types *should*
1464 // be class objects since the methodDescriptor's used
1465 // don't have generics information
1466 for(int i = 0; i < parameterClasses.length; i++)
1467 parameterClasses[i] = toClass(parameterTypes[i]);
1468
1469 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1470 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1471
1472 /*
1473 * Loop over all declared methods; match method name,
1474 * number of and type of parameters, *and* return
1475 * type. Matching return type is also necessary
1476 * because of covariant returns, etc.
1477 */
1478 ReflectionFactory fact = getReflectionFactory();
1479 for (Method m : candidates) {
1480 if (m.getName().equals(enclosingInfo.getName()) &&
1481 arrayContentsEq(parameterClasses,
1482 fact.getExecutableSharedParameterTypes(m))) {
1483 // finally, check return type
1484 if (m.getReturnType().equals(returnType)) {
1485 return fact.copyMethod(m);
1486 }
1487 }
1488 }
1489
1490 throw new InternalError("Enclosing method not found");
1491 }
1492 }
1493
1494 private native Object[] getEnclosingMethod0();
1495
1496 private EnclosingMethodInfo getEnclosingMethodInfo() {
1497 Object[] enclosingInfo = getEnclosingMethod0();
1498 if (enclosingInfo == null)
1499 return null;
1500 else {
1501 return new EnclosingMethodInfo(enclosingInfo);
1502 }
1503 }
1504
1505 private static final class EnclosingMethodInfo {
1506 private final Class<?> enclosingClass;
1507 private final String name;
1508 private final String descriptor;
1509
1510 static void validate(Object[] enclosingInfo) {
1511 if (enclosingInfo.length != 3)
1512 throw new InternalError("Malformed enclosing method information");
1513 try {
1514 // The array is expected to have three elements:
1515
1516 // the immediately enclosing class
1517 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1518 assert(enclosingClass != null);
1519
1520 // the immediately enclosing method or constructor's
1521 // name (can be null).
1522 String name = (String)enclosingInfo[1];
1523
1524 // the immediately enclosing method or constructor's
1525 // descriptor (null iff name is).
1526 String descriptor = (String)enclosingInfo[2];
1527 assert((name != null && descriptor != null) || name == descriptor);
1528 } catch (ClassCastException cce) {
1529 throw new InternalError("Invalid type in enclosing method information", cce);
1530 }
1531 }
1532
1533 EnclosingMethodInfo(Object[] enclosingInfo) {
1534 validate(enclosingInfo);
1535 this.enclosingClass = (Class<?>)enclosingInfo[0];
1536 this.name = (String)enclosingInfo[1];
1537 this.descriptor = (String)enclosingInfo[2];
1538 }
1539
1540 boolean isPartial() {
1541 return enclosingClass == null || name == null || descriptor == null;
1542 }
1543
1544 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1545
1546 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1547
1548 Class<?> getEnclosingClass() { return enclosingClass; }
1549
1550 String getName() { return name; }
1551
1552 String getDescriptor() { return descriptor; }
1553
1554 }
1555
1556 private static Class<?> toClass(Type o) {
1557 if (o instanceof GenericArrayType gat)
1558 return toClass(gat.getGenericComponentType()).arrayType();
1559 return (Class<?>)o;
1560 }
1561
1562 /**
1563 * If this {@code Class} object represents a local or anonymous
1564 * class within a constructor, returns a {@link
1565 * java.lang.reflect.Constructor Constructor} object representing
1566 * the immediately enclosing constructor of the underlying
1567 * class. Returns {@code null} otherwise. In particular, this
1568 * method returns {@code null} if the underlying class is a local
1569 * or anonymous class immediately enclosed by a class or
1570 * interface declaration, instance initializer or static initializer.
1571 *
1572 * @return the immediately enclosing constructor of the underlying class, if
1573 * that class is a local or anonymous class; otherwise {@code null}.
1574 *
1575 * @since 1.5
1576 */
1577 public Constructor<?> getEnclosingConstructor() {
1578 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1579
1580 if (enclosingInfo == null)
1581 return null;
1582 else {
1583 if (!enclosingInfo.isConstructor())
1584 return null;
1585
1586 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1587 getFactory());
1588 Type [] parameterTypes = typeInfo.getParameterTypes();
1589 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1590
1591 // Convert Types to Classes; returned types *should*
1592 // be class objects since the methodDescriptor's used
1593 // don't have generics information
1594 for (int i = 0; i < parameterClasses.length; i++)
1595 parameterClasses[i] = toClass(parameterTypes[i]);
1596
1597
1598 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1599 Constructor<?>[] candidates = enclosingCandidate
1600 .privateGetDeclaredConstructors(false);
1601 /*
1602 * Loop over all declared constructors; match number
1603 * of and type of parameters.
1604 */
1605 ReflectionFactory fact = getReflectionFactory();
1606 for (Constructor<?> c : candidates) {
1607 if (arrayContentsEq(parameterClasses,
1608 fact.getExecutableSharedParameterTypes(c))) {
1609 return fact.copyConstructor(c);
1610 }
1611 }
1612
1613 throw new InternalError("Enclosing constructor not found");
1614 }
1615 }
1616
1617
1618 /**
1619 * If the class or interface represented by this {@code Class} object
1620 * is a member of another class, returns the {@code Class} object
1621 * representing the class in which it was declared. This method returns
1622 * null if this class or interface is not a member of any other class. If
1623 * this {@code Class} object represents an array class, a primitive
1624 * type, or void, then this method returns null.
1625 *
1626 * @return the declaring class for this class
1627 * @since 1.1
1628 */
1629 public Class<?> getDeclaringClass() {
1630 return getDeclaringClass0();
1631 }
1632
1633 private native Class<?> getDeclaringClass0();
1634
1635
1636 /**
1637 * Returns the immediately enclosing class of the underlying
1638 * class. If the underlying class is a top level class this
1639 * method returns {@code null}.
1640 * @return the immediately enclosing class of the underlying class
1641 * @since 1.5
1642 */
1643 public Class<?> getEnclosingClass() {
1644 // There are five kinds of classes (or interfaces):
1645 // a) Top level classes
1646 // b) Nested classes (static member classes)
1647 // c) Inner classes (non-static member classes)
1648 // d) Local classes (named classes declared within a method)
1649 // e) Anonymous classes
1650
1651
1652 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1653 // attribute if and only if it is a local class or an
1654 // anonymous class.
1655 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1656 Class<?> enclosingCandidate;
1657
1658 if (enclosingInfo == null) {
1659 // This is a top level or a nested class or an inner class (a, b, or c)
1660 enclosingCandidate = getDeclaringClass0();
1661 } else {
1662 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1663 // This is a local class or an anonymous class (d or e)
1664 if (enclosingClass == this || enclosingClass == null)
1665 throw new InternalError("Malformed enclosing method information");
1666 else
1667 enclosingCandidate = enclosingClass;
1668 }
1669 return enclosingCandidate;
1670 }
1671
1672 /**
1673 * Returns the simple name of the underlying class as given in the
1674 * source code. An empty string is returned if the underlying class is
1675 * {@linkplain #isAnonymousClass() anonymous}.
1676 * A {@linkplain #isSynthetic() synthetic class}, one not present
1677 * in source code, can have a non-empty name including special
1678 * characters, such as "{@code $}".
1679 *
1680 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1681 * component type with "[]" appended. In particular the simple
1682 * name of an array class whose component type is anonymous is "[]".
1683 *
1684 * @return the simple name of the underlying class
1685 * @since 1.5
1686 */
1687 public String getSimpleName() {
1688 ReflectionData<T> rd = reflectionData();
1689 String simpleName = rd.simpleName;
1690 if (simpleName == null) {
1691 rd.simpleName = simpleName = getSimpleName0();
1692 }
1693 return simpleName;
1694 }
1695
1696 private String getSimpleName0() {
1697 if (isArray()) {
1698 return getComponentType().getSimpleName().concat("[]");
1699 }
1700 String simpleName = getSimpleBinaryName();
1701 if (simpleName == null) { // top level class
1702 simpleName = getName();
1703 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1704 }
1705 return simpleName;
1706 }
1707
1708 /**
1709 * Return an informative string for the name of this class or interface.
1710 *
1711 * @return an informative string for the name of this class or interface
1712 * @since 1.8
1713 */
1714 public String getTypeName() {
1715 if (isArray()) {
1716 try {
1717 Class<?> cl = this;
1718 int dimensions = 0;
1719 do {
1720 dimensions++;
1721 cl = cl.getComponentType();
1722 } while (cl.isArray());
1723 return cl.getName().concat("[]".repeat(dimensions));
1724 } catch (Throwable e) { /*FALLTHRU*/ }
1725 }
1726 return getName();
1727 }
1728
1729 /**
1730 * Returns the canonical name of the underlying class as
1731 * defined by <cite>The Java Language Specification</cite>.
1732 * Returns {@code null} if the underlying class does not have a canonical
1733 * name. Classes without canonical names include:
1734 * <ul>
1735 * <li>a {@linkplain #isLocalClass() local class}
1736 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1737 * <li>a {@linkplain #isHidden() hidden class}
1738 * <li>an array whose component type does not have a canonical name</li>
1739 * </ul>
1740 *
1741 * The canonical name for a primitive class is the keyword for the
1742 * corresponding primitive type ({@code byte}, {@code short},
1743 * {@code char}, {@code int}, and so on).
1744 *
1745 * <p>An array type has a canonical name if and only if its
1746 * component type has a canonical name. When an array type has a
1747 * canonical name, it is equal to the canonical name of the
1748 * component type followed by "{@code []}".
1749 *
1750 * @return the canonical name of the underlying class if it exists, and
1751 * {@code null} otherwise.
1752 * @jls 6.7 Fully Qualified Names and Canonical Names
1753 * @since 1.5
1754 */
1755 public String getCanonicalName() {
1756 ReflectionData<T> rd = reflectionData();
1757 String canonicalName = rd.canonicalName;
1758 if (canonicalName == null) {
1759 rd.canonicalName = canonicalName = getCanonicalName0();
1760 }
1761 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1762 }
1763
1764 private String getCanonicalName0() {
1765 if (isArray()) {
1766 String canonicalName = getComponentType().getCanonicalName();
1767 if (canonicalName != null)
1768 return canonicalName.concat("[]");
1769 else
1770 return ReflectionData.NULL_SENTINEL;
1771 }
1772 if (isHidden() || isLocalOrAnonymousClass())
1773 return ReflectionData.NULL_SENTINEL;
1774 Class<?> enclosingClass = getEnclosingClass();
1775 if (enclosingClass == null) { // top level class
1776 return getName();
1777 } else {
1778 String enclosingName = enclosingClass.getCanonicalName();
1779 if (enclosingName == null)
1780 return ReflectionData.NULL_SENTINEL;
1781 String simpleName = getSimpleName();
1782 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1783 .append(enclosingName)
1784 .append('.')
1785 .append(simpleName)
1786 .toString();
1787 }
1788 }
1789
1790 /**
1791 * Returns {@code true} if and only if the underlying class
1792 * is an anonymous class.
1793 *
1794 * @apiNote
1795 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1796 *
1797 * @return {@code true} if and only if this class is an anonymous class.
1798 * @since 1.5
1799 * @jls 15.9.5 Anonymous Class Declarations
1800 */
1801 public boolean isAnonymousClass() {
1802 return !isArray() && isLocalOrAnonymousClass() &&
1803 getSimpleBinaryName0() == null;
1804 }
1805
1806 /**
1807 * Returns {@code true} if and only if the underlying class
1808 * is a local class.
1809 *
1810 * @return {@code true} if and only if this class is a local class.
1811 * @since 1.5
1812 * @jls 14.3 Local Class and Interface Declarations
1813 */
1814 public boolean isLocalClass() {
1815 return isLocalOrAnonymousClass() &&
1816 (isArray() || getSimpleBinaryName0() != null);
1817 }
1818
1819 /**
1820 * Returns {@code true} if and only if the underlying class
1821 * is a member class.
1822 *
1823 * @return {@code true} if and only if this class is a member class.
1824 * @since 1.5
1825 * @jls 8.5 Member Class and Interface Declarations
1826 */
1827 public boolean isMemberClass() {
1828 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1829 }
1830
1831 /**
1832 * Returns the "simple binary name" of the underlying class, i.e.,
1833 * the binary name without the leading enclosing class name.
1834 * Returns {@code null} if the underlying class is a top level
1835 * class.
1836 */
1837 private String getSimpleBinaryName() {
1838 if (isTopLevelClass())
1839 return null;
1840 String name = getSimpleBinaryName0();
1841 if (name == null) // anonymous class
1842 return "";
1843 return name;
1844 }
1845
1846 private native String getSimpleBinaryName0();
1847
1848 /**
1849 * Returns {@code true} if this is a top level class. Returns {@code false}
1850 * otherwise.
1851 */
1852 private boolean isTopLevelClass() {
1853 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1854 }
1855
1856 /**
1857 * Returns {@code true} if this is a local class or an anonymous
1858 * class. Returns {@code false} otherwise.
1859 */
1860 private boolean isLocalOrAnonymousClass() {
1861 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1862 // attribute if and only if it is a local class or an
1863 // anonymous class.
1864 return hasEnclosingMethodInfo();
1865 }
1866
1867 private boolean hasEnclosingMethodInfo() {
1868 Object[] enclosingInfo = getEnclosingMethod0();
1869 if (enclosingInfo != null) {
1870 EnclosingMethodInfo.validate(enclosingInfo);
1871 return true;
1872 }
1873 return false;
1874 }
1875
1876 /**
1877 * Returns an array containing {@code Class} objects representing all
1878 * the public classes and interfaces that are members of the class
1879 * represented by this {@code Class} object. This includes public
1880 * class and interface members inherited from superclasses and public class
1881 * and interface members declared by the class. This method returns an
1882 * array of length 0 if this {@code Class} object has no public member
1883 * classes or interfaces. This method also returns an array of length 0 if
1884 * this {@code Class} object represents a primitive type, an array
1885 * class, or void.
1886 *
1887 * @return the array of {@code Class} objects representing the public
1888 * members of this class
1889 * @since 1.1
1890 */
1891 public Class<?>[] getClasses() {
1892 List<Class<?>> list = new ArrayList<>();
1893 Class<?> currentClass = Class.this;
1894 while (currentClass != null) {
1895 for (Class<?> m : currentClass.getDeclaredClasses()) {
1896 if (Modifier.isPublic(m.getModifiers())) {
1897 list.add(m);
1898 }
1899 }
1900 currentClass = currentClass.getSuperclass();
1901 }
1902 return list.toArray(new Class<?>[0]);
1903 }
1904
1905
1906 /**
1907 * Returns an array containing {@code Field} objects reflecting all
1908 * the accessible public fields of the class or interface represented by
1909 * this {@code Class} object.
1910 *
1911 * <p> If this {@code Class} object represents a class or interface with
1912 * no accessible public fields, then this method returns an array of length
1913 * 0.
1914 *
1915 * <p> If this {@code Class} object represents a class, then this method
1916 * returns the public fields of the class and of all its superclasses and
1917 * superinterfaces.
1918 *
1919 * <p> If this {@code Class} object represents an interface, then this
1920 * method returns the fields of the interface and of all its
1921 * superinterfaces.
1922 *
1923 * <p> If this {@code Class} object represents an array type, a primitive
1924 * type, or void, then this method returns an array of length 0.
1925 *
1926 * <p> The elements in the returned array are not sorted and are not in any
1927 * particular order.
1928 *
1929 * @return the array of {@code Field} objects representing the
1930 * public fields
1931 *
1932 * @since 1.1
1933 * @jls 8.2 Class Members
1934 * @jls 8.3 Field Declarations
1935 */
1936 public Field[] getFields() {
1937 return copyFields(privateGetPublicFields());
1938 }
1939
1940
1941 /**
1942 * Returns an array containing {@code Method} objects reflecting all the
1943 * public methods of the class or interface represented by this {@code
1944 * Class} object, including those declared by the class or interface and
1945 * those inherited from superclasses and superinterfaces.
1946 *
1947 * <p> If this {@code Class} object represents an array type, then the
1948 * returned array has a {@code Method} object for each of the public
1949 * methods inherited by the array type from {@code Object}. It does not
1950 * contain a {@code Method} object for {@code clone()}.
1951 *
1952 * <p> If this {@code Class} object represents an interface then the
1953 * returned array does not contain any implicitly declared methods from
1954 * {@code Object}. Therefore, if no methods are explicitly declared in
1955 * this interface or any of its superinterfaces then the returned array
1956 * has length 0. (Note that a {@code Class} object which represents a class
1957 * always has public methods, inherited from {@code Object}.)
1958 *
1959 * <p> The returned array never contains methods with names {@value
1960 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1961 *
1962 * <p> The elements in the returned array are not sorted and are not in any
1963 * particular order.
1964 *
1965 * <p> Generally, the result is computed as with the following 4 step algorithm.
1966 * Let C be the class or interface represented by this {@code Class} object:
1967 * <ol>
1968 * <li> A union of methods is composed of:
1969 * <ol type="a">
1970 * <li> C's declared public instance and static methods as returned by
1971 * {@link #getDeclaredMethods()} and filtered to include only public
1972 * methods.</li>
1973 * <li> If C is a class other than {@code Object}, then include the result
1974 * of invoking this algorithm recursively on the superclass of C.</li>
1975 * <li> Include the results of invoking this algorithm recursively on all
1976 * direct superinterfaces of C, but include only instance methods.</li>
1977 * </ol></li>
1978 * <li> Union from step 1 is partitioned into subsets of methods with same
1979 * signature (name, parameter types) and return type.</li>
1980 * <li> Within each such subset only the most specific methods are selected.
1981 * Let method M be a method from a set of methods with same signature
1982 * and return type. M is most specific if there is no such method
1983 * N != M from the same set, such that N is more specific than M.
1984 * N is more specific than M if:
1985 * <ol type="a">
1986 * <li> N is declared by a class and M is declared by an interface; or</li>
1987 * <li> N and M are both declared by classes or both by interfaces and
1988 * N's declaring type is the same as or a subtype of M's declaring type
1989 * (clearly, if M's and N's declaring types are the same type, then
1990 * M and N are the same method).</li>
1991 * </ol></li>
1992 * <li> The result of this algorithm is the union of all selected methods from
1993 * step 3.</li>
1994 * </ol>
1995 *
1996 * @apiNote There may be more than one method with a particular name
1997 * and parameter types in a class because while the Java language forbids a
1998 * class to declare multiple methods with the same signature but different
1999 * return types, the Java virtual machine does not. This
2000 * increased flexibility in the virtual machine can be used to
2001 * implement various language features. For example, covariant
2002 * returns can be implemented with {@linkplain
2003 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2004 * method and the overriding method would have the same
2005 * signature but different return types.
2006 *
2007 * @return the array of {@code Method} objects representing the
2008 * public methods of this class
2009 *
2010 * @jls 8.2 Class Members
2011 * @jls 8.4 Method Declarations
2012 * @since 1.1
2013 */
2014 public Method[] getMethods() {
2015 return copyMethods(privateGetPublicMethods());
2016 }
2017
2018
2019 /**
2020 * Returns an array containing {@code Constructor} objects reflecting
2021 * all the public constructors of the class represented by this
2022 * {@code Class} object. An array of length 0 is returned if the
2023 * class has no public constructors, or if the class is an array class, or
2024 * if the class reflects a primitive type or void.
2025 *
2026 * @apiNote
2027 * While this method returns an array of {@code
2028 * Constructor<T>} objects (that is an array of constructors from
2029 * this class), the return type of this method is {@code
2030 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2031 * might be expected. This less informative return type is
2032 * necessary since after being returned from this method, the
2033 * array could be modified to hold {@code Constructor} objects for
2034 * different classes, which would violate the type guarantees of
2035 * {@code Constructor<T>[]}.
2036 *
2037 * @return the array of {@code Constructor} objects representing the
2038 * public constructors of this class
2039 *
2040 * @see #getDeclaredConstructors()
2041 * @since 1.1
2042 */
2043 public Constructor<?>[] getConstructors() {
2044 return copyConstructors(privateGetDeclaredConstructors(true));
2045 }
2046
2047
2048 /**
2049 * Returns a {@code Field} object that reflects the specified public member
2050 * field of the class or interface represented by this {@code Class}
2051 * object. The {@code name} parameter is a {@code String} specifying the
2052 * simple name of the desired field.
2053 *
2054 * <p> The field to be reflected is determined by the algorithm that
2055 * follows. Let C be the class or interface represented by this {@code Class} object:
2056 *
2057 * <OL>
2058 * <LI> If C declares a public field with the name specified, that is the
2059 * field to be reflected.</LI>
2060 * <LI> If no field was found in step 1 above, this algorithm is applied
2061 * recursively to each direct superinterface of C. The direct
2062 * superinterfaces are searched in the order they were declared.</LI>
2063 * <LI> If no field was found in steps 1 and 2 above, and C has a
2064 * superclass S, then this algorithm is invoked recursively upon S.
2065 * If C has no superclass, then a {@code NoSuchFieldException}
2066 * is thrown.</LI>
2067 * </OL>
2068 *
2069 * <p> If this {@code Class} object represents an array type, then this
2070 * method does not find the {@code length} field of the array type.
2071 *
2072 * @param name the field name
2073 * @return the {@code Field} object of this class specified by
2074 * {@code name}
2075 * @throws NoSuchFieldException if a field with the specified name is
2076 * not found.
2077 * @throws NullPointerException if {@code name} is {@code null}
2078 *
2079 * @since 1.1
2080 * @jls 8.2 Class Members
2081 * @jls 8.3 Field Declarations
2082 */
2083 public Field getField(String name) throws NoSuchFieldException {
2084 Objects.requireNonNull(name);
2085 Field field = getField0(name);
2086 if (field == null) {
2087 throw new NoSuchFieldException(name);
2088 }
2089 return getReflectionFactory().copyField(field);
2090 }
2091
2092
2093 /**
2094 * Returns a {@code Method} object that reflects the specified public
2095 * member method of the class or interface represented by this
2096 * {@code Class} object. The {@code name} parameter is a
2097 * {@code String} specifying the simple name of the desired method. The
2098 * {@code parameterTypes} parameter is an array of {@code Class}
2099 * objects that identify the method's formal parameter types, in declared
2100 * order. If {@code parameterTypes} is {@code null}, it is
2101 * treated as if it were an empty array.
2102 *
2103 * <p> If this {@code Class} object represents an array type, then this
2104 * method finds any public method inherited by the array type from
2105 * {@code Object} except method {@code clone()}.
2106 *
2107 * <p> If this {@code Class} object represents an interface then this
2108 * method does not find any implicitly declared method from
2109 * {@code Object}. Therefore, if no methods are explicitly declared in
2110 * this interface or any of its superinterfaces, then this method does not
2111 * find any method.
2112 *
2113 * <p> This method does not find any method with name {@value
2114 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2115 *
2116 * <p> Generally, the method to be reflected is determined by the 4 step
2117 * algorithm that follows.
2118 * Let C be the class or interface represented by this {@code Class} object:
2119 * <ol>
2120 * <li> A union of methods is composed of:
2121 * <ol type="a">
2122 * <li> C's declared public instance and static methods as returned by
2123 * {@link #getDeclaredMethods()} and filtered to include only public
2124 * methods that match given {@code name} and {@code parameterTypes}</li>
2125 * <li> If C is a class other than {@code Object}, then include the result
2126 * of invoking this algorithm recursively on the superclass of C.</li>
2127 * <li> Include the results of invoking this algorithm recursively on all
2128 * direct superinterfaces of C, but include only instance methods.</li>
2129 * </ol></li>
2130 * <li> This union is partitioned into subsets of methods with same
2131 * return type (the selection of methods from step 1 also guarantees that
2132 * they have the same method name and parameter types).</li>
2133 * <li> Within each such subset only the most specific methods are selected.
2134 * Let method M be a method from a set of methods with same VM
2135 * signature (return type, name, parameter types).
2136 * M is most specific if there is no such method N != M from the same
2137 * set, such that N is more specific than M. N is more specific than M
2138 * if:
2139 * <ol type="a">
2140 * <li> N is declared by a class and M is declared by an interface; or</li>
2141 * <li> N and M are both declared by classes or both by interfaces and
2142 * N's declaring type is the same as or a subtype of M's declaring type
2143 * (clearly, if M's and N's declaring types are the same type, then
2144 * M and N are the same method).</li>
2145 * </ol></li>
2146 * <li> The result of this algorithm is chosen arbitrarily from the methods
2147 * with most specific return type among all selected methods from step 3.
2148 * Let R be a return type of a method M from the set of all selected methods
2149 * from step 3. M is a method with most specific return type if there is
2150 * no such method N != M from the same set, having return type S != R,
2151 * such that S is a subtype of R as determined by
2152 * R.class.{@link #isAssignableFrom}(S.class).
2153 * </ol>
2154 *
2155 * @apiNote There may be more than one method with matching name and
2156 * parameter types in a class because while the Java language forbids a
2157 * class to declare multiple methods with the same signature but different
2158 * return types, the Java virtual machine does not. This
2159 * increased flexibility in the virtual machine can be used to
2160 * implement various language features. For example, covariant
2161 * returns can be implemented with {@linkplain
2162 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2163 * method and the overriding method would have the same
2164 * signature but different return types. This method would return the
2165 * overriding method as it would have a more specific return type.
2166 *
2167 * @param name the name of the method
2168 * @param parameterTypes the list of parameters
2169 * @return the {@code Method} object that matches the specified
2170 * {@code name} and {@code parameterTypes}
2171 * @throws NoSuchMethodException if a matching method is not found
2172 * or if the name is {@value ConstantDescs#INIT_NAME} or
2173 * {@value ConstantDescs#CLASS_INIT_NAME}.
2174 * @throws NullPointerException if {@code name} is {@code null}
2175 *
2176 * @jls 8.2 Class Members
2177 * @jls 8.4 Method Declarations
2178 * @since 1.1
2179 */
2180 public Method getMethod(String name, Class<?>... parameterTypes)
2181 throws NoSuchMethodException {
2182 Objects.requireNonNull(name);
2183 Method method = getMethod0(name, parameterTypes);
2184 if (method == null) {
2185 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2186 }
2187 return getReflectionFactory().copyMethod(method);
2188 }
2189
2190 /**
2191 * Returns a {@code Constructor} object that reflects the specified
2192 * public constructor of the class represented by this {@code Class}
2193 * object. The {@code parameterTypes} parameter is an array of
2194 * {@code Class} objects that identify the constructor's formal
2195 * parameter types, in declared order.
2196 *
2197 * If this {@code Class} object represents an inner class
2198 * declared in a non-static context, the formal parameter types
2199 * include the explicit enclosing instance as the first parameter.
2200 *
2201 * <p> The constructor to reflect is the public constructor of the class
2202 * represented by this {@code Class} object whose formal parameter
2203 * types match those specified by {@code parameterTypes}.
2204 *
2205 * @param parameterTypes the parameter array
2206 * @return the {@code Constructor} object of the public constructor that
2207 * matches the specified {@code parameterTypes}
2208 * @throws NoSuchMethodException if a matching constructor is not found,
2209 * including when this {@code Class} object represents
2210 * an interface, a primitive type, an array class, or void.
2211 *
2212 * @see #getDeclaredConstructor(Class[])
2213 * @since 1.1
2214 */
2215 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2216 throws NoSuchMethodException {
2217 return getReflectionFactory().copyConstructor(
2218 getConstructor0(parameterTypes, Member.PUBLIC));
2219 }
2220
2221
2222 /**
2223 * Returns an array of {@code Class} objects reflecting all the
2224 * classes and interfaces declared as members of the class represented by
2225 * this {@code Class} object. This includes public, protected, default
2226 * (package) access, and private classes and interfaces declared by the
2227 * class, but excludes inherited classes and interfaces. This method
2228 * returns an array of length 0 if the class declares no classes or
2229 * interfaces as members, or if this {@code Class} object represents a
2230 * primitive type, an array class, or void.
2231 *
2232 * @return the array of {@code Class} objects representing all the
2233 * declared members of this class
2234 *
2235 * @since 1.1
2236 * @jls 8.5 Member Class and Interface Declarations
2237 */
2238 public Class<?>[] getDeclaredClasses() {
2239 return getDeclaredClasses0();
2240 }
2241
2242
2243 /**
2244 * Returns an array of {@code Field} objects reflecting all the fields
2245 * declared by the class or interface represented by this
2246 * {@code Class} object. This includes public, protected, default
2247 * (package) access, and private fields, but excludes inherited fields.
2248 *
2249 * <p> If this {@code Class} object represents a class or interface with no
2250 * declared fields, then this method returns an array of length 0.
2251 *
2252 * <p> If this {@code Class} object represents an array type, a primitive
2253 * type, or void, then this method returns an array of length 0.
2254 *
2255 * <p> The elements in the returned array are not sorted and are not in any
2256 * particular order.
2257 *
2258 * @return the array of {@code Field} objects representing all the
2259 * declared fields of this class
2260 *
2261 * @since 1.1
2262 * @jls 8.2 Class Members
2263 * @jls 8.3 Field Declarations
2264 */
2265 public Field[] getDeclaredFields() {
2266 return copyFields(privateGetDeclaredFields(false));
2267 }
2268
2269 /**
2270 * Returns an array of {@code RecordComponent} objects representing all the
2271 * record components of this record class, or {@code null} if this class is
2272 * not a record class.
2273 *
2274 * <p> The components are returned in the same order that they are declared
2275 * in the record header. The array is empty if this record class has no
2276 * components. If the class is not a record class, that is {@link
2277 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2278 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2279 * returns a non-null value.
2280 *
2281 * @apiNote
2282 * <p> The following method can be used to find the record canonical constructor:
2283 *
2284 * {@snippet lang="java" :
2285 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2286 * throws NoSuchMethodException {
2287 * Class<?>[] paramTypes =
2288 * Arrays.stream(cls.getRecordComponents())
2289 * .map(RecordComponent::getType)
2290 * .toArray(Class<?>[]::new);
2291 * return cls.getDeclaredConstructor(paramTypes);
2292 * }}
2293 *
2294 * @return An array of {@code RecordComponent} objects representing all the
2295 * record components of this record class, or {@code null} if this
2296 * class is not a record class
2297 *
2298 * @jls 8.10 Record Classes
2299 * @since 16
2300 */
2301 public RecordComponent[] getRecordComponents() {
2302 if (!isRecord()) {
2303 return null;
2304 }
2305 return getRecordComponents0();
2306 }
2307
2308 /**
2309 * Returns an array containing {@code Method} objects reflecting all the
2310 * declared methods of the class or interface represented by this {@code
2311 * Class} object, including public, protected, default (package)
2312 * access, and private methods, but excluding inherited methods.
2313 * The declared methods may include methods <em>not</em> in the
2314 * source of the class or interface, including {@linkplain
2315 * Method#isBridge bridge methods} and other {@linkplain
2316 * Executable#isSynthetic synthetic} methods added by compilers.
2317 *
2318 * <p> If this {@code Class} object represents a class or interface that
2319 * has multiple declared methods with the same name and parameter types,
2320 * but different return types, then the returned array has a {@code Method}
2321 * object for each such method.
2322 *
2323 * <p> If this {@code Class} object represents a class or interface that
2324 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2325 * then the returned array does <em>not</em> have a corresponding {@code
2326 * Method} object.
2327 *
2328 * <p> If this {@code Class} object represents a class or interface with no
2329 * declared methods, then the returned array has length 0.
2330 *
2331 * <p> If this {@code Class} object represents an array type, a primitive
2332 * type, or void, then the returned array has length 0.
2333 *
2334 * <p> The elements in the returned array are not sorted and are not in any
2335 * particular order.
2336 *
2337 * @return the array of {@code Method} objects representing all the
2338 * declared methods of this class
2339 *
2340 * @jls 8.2 Class Members
2341 * @jls 8.4 Method Declarations
2342 * @see <a
2343 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2344 * programming language and JVM modeling in core reflection</a>
2345 * @since 1.1
2346 */
2347 public Method[] getDeclaredMethods() {
2348 return copyMethods(privateGetDeclaredMethods(false));
2349 }
2350
2351 /**
2352 * Returns an array of {@code Constructor} objects reflecting all the
2353 * constructors implicitly or explicitly declared by the class represented by this
2354 * {@code Class} object. These are public, protected, default
2355 * (package) access, and private constructors. The elements in the array
2356 * returned are not sorted and are not in any particular order. If the
2357 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2358 * If a record class has a canonical constructor (JLS {@jls
2359 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2360 *
2361 * This method returns an array of length 0 if this {@code Class}
2362 * object represents an interface, a primitive type, an array class, or
2363 * void.
2364 *
2365 * @return the array of {@code Constructor} objects representing all the
2366 * declared constructors of this class
2367 *
2368 * @since 1.1
2369 * @see #getConstructors()
2370 * @jls 8.8 Constructor Declarations
2371 */
2372 public Constructor<?>[] getDeclaredConstructors() {
2373 return copyConstructors(privateGetDeclaredConstructors(false));
2374 }
2375
2376
2377 /**
2378 * Returns a {@code Field} object that reflects the specified declared
2379 * field of the class or interface represented by this {@code Class}
2380 * object. The {@code name} parameter is a {@code String} that specifies
2381 * the simple name of the desired field.
2382 *
2383 * <p> If this {@code Class} object represents an array type, then this
2384 * method does not find the {@code length} field of the array type.
2385 *
2386 * @param name the name of the field
2387 * @return the {@code Field} object for the specified field in this
2388 * class
2389 * @throws NoSuchFieldException if a field with the specified name is
2390 * not found.
2391 * @throws NullPointerException if {@code name} is {@code null}
2392 *
2393 * @since 1.1
2394 * @jls 8.2 Class Members
2395 * @jls 8.3 Field Declarations
2396 */
2397 public Field getDeclaredField(String name) throws NoSuchFieldException {
2398 Objects.requireNonNull(name);
2399 Field field = searchFields(privateGetDeclaredFields(false), name);
2400 if (field == null) {
2401 throw new NoSuchFieldException(name);
2402 }
2403 return getReflectionFactory().copyField(field);
2404 }
2405
2406
2407 /**
2408 * Returns a {@code Method} object that reflects the specified
2409 * declared method of the class or interface represented by this
2410 * {@code Class} object. The {@code name} parameter is a
2411 * {@code String} that specifies the simple name of the desired
2412 * method, and the {@code parameterTypes} parameter is an array of
2413 * {@code Class} objects that identify the method's formal parameter
2414 * types, in declared order. If more than one method with the same
2415 * parameter types is declared in a class, and one of these methods has a
2416 * return type that is more specific than any of the others, that method is
2417 * returned; otherwise one of the methods is chosen arbitrarily. If the
2418 * name is {@value ConstantDescs#INIT_NAME} or {@value
2419 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2420 * is raised.
2421 *
2422 * <p> If this {@code Class} object represents an array type, then this
2423 * method does not find the {@code clone()} method.
2424 *
2425 * @param name the name of the method
2426 * @param parameterTypes the parameter array
2427 * @return the {@code Method} object for the method of this class
2428 * matching the specified name and parameters
2429 * @throws NoSuchMethodException if a matching method is not found.
2430 * @throws NullPointerException if {@code name} is {@code null}
2431 *
2432 * @jls 8.2 Class Members
2433 * @jls 8.4 Method Declarations
2434 * @since 1.1
2435 */
2436 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2437 throws NoSuchMethodException {
2438 Objects.requireNonNull(name);
2439 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2440 if (method == null) {
2441 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2442 }
2443 return getReflectionFactory().copyMethod(method);
2444 }
2445
2446 /**
2447 * Returns the list of {@code Method} objects for the declared public
2448 * methods of this class or interface that have the specified method name
2449 * and parameter types.
2450 *
2451 * @param name the name of the method
2452 * @param parameterTypes the parameter array
2453 * @return the list of {@code Method} objects for the public methods of
2454 * this class matching the specified name and parameters
2455 */
2456 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2457 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2458 ReflectionFactory factory = getReflectionFactory();
2459 List<Method> result = new ArrayList<>();
2460 for (Method method : methods) {
2461 if (method.getName().equals(name)
2462 && Arrays.equals(
2463 factory.getExecutableSharedParameterTypes(method),
2464 parameterTypes)) {
2465 result.add(factory.copyMethod(method));
2466 }
2467 }
2468 return result;
2469 }
2470
2471 /**
2472 * Returns the most specific {@code Method} object of this class, super class or
2473 * interface that have the specified method name and parameter types.
2474 *
2475 * @param publicOnly true if only public methods are examined, otherwise all methods
2476 * @param name the name of the method
2477 * @param parameterTypes the parameter array
2478 * @return the {@code Method} object for the method found from this class matching
2479 * the specified name and parameters, or null if not found
2480 */
2481 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2482 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2483 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2484 }
2485
2486 /**
2487 * Returns a {@code Constructor} object that reflects the specified
2488 * constructor of the class represented by this
2489 * {@code Class} object. The {@code parameterTypes} parameter is
2490 * an array of {@code Class} objects that identify the constructor's
2491 * formal parameter types, in declared order.
2492 *
2493 * If this {@code Class} object represents an inner class
2494 * declared in a non-static context, the formal parameter types
2495 * include the explicit enclosing instance as the first parameter.
2496 *
2497 * @param parameterTypes the parameter array
2498 * @return The {@code Constructor} object for the constructor with the
2499 * specified parameter list
2500 * @throws NoSuchMethodException if a matching constructor is not found,
2501 * including when this {@code Class} object represents
2502 * an interface, a primitive type, an array class, or void.
2503 *
2504 * @see #getConstructor(Class[])
2505 * @since 1.1
2506 */
2507 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2508 throws NoSuchMethodException {
2509 return getReflectionFactory().copyConstructor(
2510 getConstructor0(parameterTypes, Member.DECLARED));
2511 }
2512
2513 /**
2514 * Finds a resource with a given name.
2515 *
2516 * <p> If this class is in a named {@link Module Module} then this method
2517 * will attempt to find the resource in the module. This is done by
2518 * delegating to the module's class loader {@link
2519 * ClassLoader#findResource(String,String) findResource(String,String)}
2520 * method, invoking it with the module name and the absolute name of the
2521 * resource. Resources in named modules are subject to the rules for
2522 * encapsulation specified in the {@code Module} {@link
2523 * Module#getResourceAsStream getResourceAsStream} method and so this
2524 * method returns {@code null} when the resource is a
2525 * non-"{@code .class}" resource in a package that is not open to the
2526 * caller's module.
2527 *
2528 * <p> Otherwise, if this class is not in a named module then the rules for
2529 * searching resources associated with a given class are implemented by the
2530 * defining {@linkplain ClassLoader class loader} of the class. This method
2531 * delegates to this {@code Class} object's class loader.
2532 * If this {@code Class} object was loaded by the bootstrap class loader,
2533 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2534 *
2535 * <p> Before delegation, an absolute resource name is constructed from the
2536 * given resource name using this algorithm:
2537 *
2538 * <ul>
2539 *
2540 * <li> If the {@code name} begins with a {@code '/'}
2541 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2542 * portion of the {@code name} following the {@code '/'}.
2543 *
2544 * <li> Otherwise, the absolute name is of the following form:
2545 *
2546 * <blockquote>
2547 * {@code modified_package_name/name}
2548 * </blockquote>
2549 *
2550 * <p> Where the {@code modified_package_name} is the package name of this
2551 * object with {@code '/'} substituted for {@code '.'}
2552 * (<code>'\u002e'</code>).
2553 *
2554 * </ul>
2555 *
2556 * @param name name of the desired resource
2557 * @return A {@link java.io.InputStream} object; {@code null} if no
2558 * resource with this name is found, or the resource is in a package
2559 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2560 * least the caller module.
2561 * @throws NullPointerException If {@code name} is {@code null}
2562 *
2563 * @see Module#getResourceAsStream(String)
2564 * @since 1.1
2565 */
2566 @CallerSensitive
2567 public InputStream getResourceAsStream(String name) {
2568 name = resolveName(name);
2569
2570 Module thisModule = getModule();
2571 if (thisModule.isNamed()) {
2572 // check if resource can be located by caller
2573 if (Resources.canEncapsulate(name)
2574 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2575 return null;
2576 }
2577
2578 // resource not encapsulated or in package open to caller
2579 String mn = thisModule.getName();
2580 ClassLoader cl = classLoader;
2581 try {
2582
2583 // special-case built-in class loaders to avoid the
2584 // need for a URL connection
2585 if (cl == null) {
2586 return BootLoader.findResourceAsStream(mn, name);
2587 } else if (cl instanceof BuiltinClassLoader bcl) {
2588 return bcl.findResourceAsStream(mn, name);
2589 } else {
2590 URL url = cl.findResource(mn, name);
2591 return (url != null) ? url.openStream() : null;
2592 }
2593
2594 } catch (IOException | SecurityException e) {
2595 return null;
2596 }
2597 }
2598
2599 // unnamed module
2600 ClassLoader cl = classLoader;
2601 if (cl == null) {
2602 return ClassLoader.getSystemResourceAsStream(name);
2603 } else {
2604 return cl.getResourceAsStream(name);
2605 }
2606 }
2607
2608 /**
2609 * Finds a resource with a given name.
2610 *
2611 * <p> If this class is in a named {@link Module Module} then this method
2612 * will attempt to find the resource in the module. This is done by
2613 * delegating to the module's class loader {@link
2614 * ClassLoader#findResource(String,String) findResource(String,String)}
2615 * method, invoking it with the module name and the absolute name of the
2616 * resource. Resources in named modules are subject to the rules for
2617 * encapsulation specified in the {@code Module} {@link
2618 * Module#getResourceAsStream getResourceAsStream} method and so this
2619 * method returns {@code null} when the resource is a
2620 * non-"{@code .class}" resource in a package that is not open to the
2621 * caller's module.
2622 *
2623 * <p> Otherwise, if this class is not in a named module then the rules for
2624 * searching resources associated with a given class are implemented by the
2625 * defining {@linkplain ClassLoader class loader} of the class. This method
2626 * delegates to this {@code Class} object's class loader.
2627 * If this {@code Class} object was loaded by the bootstrap class loader,
2628 * the method delegates to {@link ClassLoader#getSystemResource}.
2629 *
2630 * <p> Before delegation, an absolute resource name is constructed from the
2631 * given resource name using this algorithm:
2632 *
2633 * <ul>
2634 *
2635 * <li> If the {@code name} begins with a {@code '/'}
2636 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2637 * portion of the {@code name} following the {@code '/'}.
2638 *
2639 * <li> Otherwise, the absolute name is of the following form:
2640 *
2641 * <blockquote>
2642 * {@code modified_package_name/name}
2643 * </blockquote>
2644 *
2645 * <p> Where the {@code modified_package_name} is the package name of this
2646 * object with {@code '/'} substituted for {@code '.'}
2647 * (<code>'\u002e'</code>).
2648 *
2649 * </ul>
2650 *
2651 * @param name name of the desired resource
2652 * @return A {@link java.net.URL} object; {@code null} if no resource with
2653 * this name is found, the resource cannot be located by a URL, or the
2654 * resource is in a package that is not
2655 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2656 * module.
2657 * @throws NullPointerException If {@code name} is {@code null}
2658 * @since 1.1
2659 */
2660 @CallerSensitive
2661 public URL getResource(String name) {
2662 name = resolveName(name);
2663
2664 Module thisModule = getModule();
2665 if (thisModule.isNamed()) {
2666 // check if resource can be located by caller
2667 if (Resources.canEncapsulate(name)
2668 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2669 return null;
2670 }
2671
2672 // resource not encapsulated or in package open to caller
2673 String mn = thisModule.getName();
2674 ClassLoader cl = classLoader;
2675 try {
2676 if (cl == null) {
2677 return BootLoader.findResource(mn, name);
2678 } else {
2679 return cl.findResource(mn, name);
2680 }
2681 } catch (IOException ioe) {
2682 return null;
2683 }
2684 }
2685
2686 // unnamed module
2687 ClassLoader cl = classLoader;
2688 if (cl == null) {
2689 return ClassLoader.getSystemResource(name);
2690 } else {
2691 return cl.getResource(name);
2692 }
2693 }
2694
2695 /**
2696 * Returns true if a resource with the given name can be located by the
2697 * given caller. All resources in a module can be located by code in
2698 * the module. For other callers, then the package needs to be open to
2699 * the caller.
2700 */
2701 private boolean isOpenToCaller(String name, Class<?> caller) {
2702 // assert getModule().isNamed();
2703 Module thisModule = getModule();
2704 Module callerModule = (caller != null) ? caller.getModule() : null;
2705 if (callerModule != thisModule) {
2706 String pn = Resources.toPackageName(name);
2707 if (thisModule.getDescriptor().packages().contains(pn)) {
2708 if (callerModule == null) {
2709 // no caller, return true if the package is open to all modules
2710 return thisModule.isOpen(pn);
2711 }
2712 if (!thisModule.isOpen(pn, callerModule)) {
2713 // package not open to caller
2714 return false;
2715 }
2716 }
2717 }
2718 return true;
2719 }
2720
2721 /**
2722 * Returns the {@code ProtectionDomain} of this class.
2723 *
2724 * @return the ProtectionDomain of this class
2725 *
2726 * @see java.security.ProtectionDomain
2727 * @since 1.2
2728 */
2729 public ProtectionDomain getProtectionDomain() {
2730 return protectionDomain();
2731 }
2732
2733 /** Holder for the protection domain returned when the internal domain is null */
2734 private static class Holder {
2735 private static final ProtectionDomain allPermDomain;
2736 static {
2737 Permissions perms = new Permissions();
2738 perms.add(new AllPermission());
2739 allPermDomain = new ProtectionDomain(null, perms);
2740 }
2741 }
2742
2743 // package-private
2744 ProtectionDomain protectionDomain() {
2745 ProtectionDomain pd = getProtectionDomain0();
2746 if (pd == null) {
2747 return Holder.allPermDomain;
2748 } else {
2749 return pd;
2750 }
2751 }
2752
2753 /**
2754 * Returns the ProtectionDomain of this class.
2755 */
2756 private native ProtectionDomain getProtectionDomain0();
2757
2758 /*
2759 * Returns the Class object for the named primitive type. Type parameter T
2760 * avoids redundant casts for trusted code.
2761 */
2762 static native <T> Class<T> getPrimitiveClass(String name);
2763
2764 /**
2765 * Add a package name prefix if the name is not absolute. Remove leading "/"
2766 * if name is absolute
2767 */
2768 private String resolveName(String name) {
2769 if (!name.startsWith("/")) {
2770 String baseName = getPackageName();
2771 if (!baseName.isEmpty()) {
2772 int len = baseName.length() + 1 + name.length();
2773 StringBuilder sb = new StringBuilder(len);
2774 name = sb.append(baseName.replace('.', '/'))
2775 .append('/')
2776 .append(name)
2777 .toString();
2778 }
2779 } else {
2780 name = name.substring(1);
2781 }
2782 return name;
2783 }
2784
2785 /**
2786 * Atomic operations support.
2787 */
2788 private static class Atomic {
2789 // initialize Unsafe machinery here, since we need to call Class.class instance method
2790 // and have to avoid calling it in the static initializer of the Class class...
2791 private static final Unsafe unsafe = Unsafe.getUnsafe();
2792 // offset of Class.reflectionData instance field
2793 private static final long reflectionDataOffset
2794 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2795 // offset of Class.annotationType instance field
2796 private static final long annotationTypeOffset
2797 = unsafe.objectFieldOffset(Class.class, "annotationType");
2798 // offset of Class.annotationData instance field
2799 private static final long annotationDataOffset
2800 = unsafe.objectFieldOffset(Class.class, "annotationData");
2801
2802 static <T> boolean casReflectionData(Class<?> clazz,
2803 ReflectionData<T> oldData,
2804 ReflectionData<T> newData) {
2805 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2806 }
2807
2808 static boolean casAnnotationType(Class<?> clazz,
2809 AnnotationType oldType,
2810 AnnotationType newType) {
2811 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2812 }
2813
2814 static boolean casAnnotationData(Class<?> clazz,
2815 AnnotationData oldData,
2816 AnnotationData newData) {
2817 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2818 }
2819 }
2820
2821 /**
2822 * Reflection support.
2823 */
2824
2825 // Reflection data caches various derived names and reflective members. Cached
2826 // values may be invalidated when JVM TI RedefineClasses() is called
2827 private static class ReflectionData<T> {
2828 volatile Field[] declaredFields;
2829 volatile Field[] publicFields;
2830 volatile Method[] declaredMethods;
2831 volatile Method[] publicMethods;
2832 volatile Constructor<T>[] declaredConstructors;
2833 volatile Constructor<T>[] publicConstructors;
2834 // Intermediate results for getFields and getMethods
2835 volatile Field[] declaredPublicFields;
2836 volatile Method[] declaredPublicMethods;
2837 volatile Class<?>[] interfaces;
2838
2839 // Cached names
2840 String simpleName;
2841 String canonicalName;
2842 static final String NULL_SENTINEL = new String();
2843
2844 // Value of classRedefinedCount when we created this ReflectionData instance
2845 final int redefinedCount;
2846
2847 ReflectionData(int redefinedCount) {
2848 this.redefinedCount = redefinedCount;
2849 }
2850 }
2851
2852 private transient volatile ReflectionData<T> reflectionData;
2853
2854 // Incremented by the VM on each call to JVM TI RedefineClasses()
2855 // that redefines this class or a superclass.
2856 private transient volatile int classRedefinedCount;
2857
2858 // Lazily create and cache ReflectionData
2859 private ReflectionData<T> reflectionData() {
2860 ReflectionData<T> reflectionData = this.reflectionData;
2861 int classRedefinedCount = this.classRedefinedCount;
2862 if (reflectionData != null &&
2863 reflectionData.redefinedCount == classRedefinedCount) {
2864 return reflectionData;
2865 }
2866 // else no SoftReference or cleared SoftReference or stale ReflectionData
2867 // -> create and replace new instance
2868 return newReflectionData(reflectionData, classRedefinedCount);
2869 }
2870
2871 private ReflectionData<T> newReflectionData(ReflectionData<T> oldReflectionData,
2872 int classRedefinedCount) {
2873 while (true) {
2874 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2875 // try to CAS it...
2876 if (Atomic.casReflectionData(this, oldReflectionData, rd)) {
2877 return rd;
2878 }
2879 // else retry
2880 oldReflectionData = this.reflectionData;
2881 classRedefinedCount = this.classRedefinedCount;
2882 if (oldReflectionData != null && oldReflectionData.redefinedCount == classRedefinedCount) {
2883 return rd;
2884 }
2885 }
2886 }
2887
2888 // Generic signature handling
2889 private native String getGenericSignature0();
2890
2891 // Generic info repository; lazily initialized
2892 private transient volatile ClassRepository genericInfo;
2893
2894 // accessor for factory
2895 private GenericsFactory getFactory() {
2896 // create scope and factory
2897 return CoreReflectionFactory.make(this, ClassScope.make(this));
2898 }
2899
2900 // accessor for generic info repository;
2901 // generic info is lazily initialized
2902 private ClassRepository getGenericInfo() {
2903 ClassRepository genericInfo = this.genericInfo;
2904 if (genericInfo == null) {
2905 String signature = getGenericSignature0();
2906 if (signature == null) {
2907 genericInfo = ClassRepository.NONE;
2908 } else {
2909 genericInfo = ClassRepository.make(signature, getFactory());
2910 }
2911 this.genericInfo = genericInfo;
2912 }
2913 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2914 }
2915
2916 // Annotations handling
2917 native byte[] getRawAnnotations();
2918 // Since 1.8
2919 native byte[] getRawTypeAnnotations();
2920 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2921 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2922 }
2923
2924 native ConstantPool getConstantPool();
2925
2926 //
2927 //
2928 // java.lang.reflect.Field handling
2929 //
2930 //
2931
2932 // Returns an array of "root" fields. These Field objects must NOT
2933 // be propagated to the outside world, but must instead be copied
2934 // via ReflectionFactory.copyField.
2935 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2936 Field[] res;
2937 ReflectionData<T> rd = reflectionData();
2938 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2939 if (res != null) return res;
2940 // No cached value available; request value from VM
2941 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2942 if (publicOnly) {
2943 rd.declaredPublicFields = res;
2944 } else {
2945 rd.declaredFields = res;
2946 }
2947 return res;
2948 }
2949
2950 // Returns an array of "root" fields. These Field objects must NOT
2951 // be propagated to the outside world, but must instead be copied
2952 // via ReflectionFactory.copyField.
2953 private Field[] privateGetPublicFields() {
2954 Field[] res;
2955 ReflectionData<T> rd = reflectionData();
2956 res = rd.publicFields;
2957 if (res != null) return res;
2958
2959 // Use a linked hash set to ensure order is preserved and
2960 // fields from common super interfaces are not duplicated
2961 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2962
2963 // Local fields
2964 addAll(fields, privateGetDeclaredFields(true));
2965
2966 // Direct superinterfaces, recursively
2967 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2968 addAll(fields, si.privateGetPublicFields());
2969 }
2970
2971 // Direct superclass, recursively
2972 Class<?> sc = getSuperclass();
2973 if (sc != null) {
2974 addAll(fields, sc.privateGetPublicFields());
2975 }
2976
2977 res = fields.toArray(new Field[0]);
2978 rd.publicFields = res;
2979 return res;
2980 }
2981
2982 private static void addAll(Collection<Field> c, Field[] o) {
2983 for (Field f : o) {
2984 c.add(f);
2985 }
2986 }
2987
2988
2989 //
2990 //
2991 // java.lang.reflect.Constructor handling
2992 //
2993 //
2994
2995 // Returns an array of "root" constructors. These Constructor
2996 // objects must NOT be propagated to the outside world, but must
2997 // instead be copied via ReflectionFactory.copyConstructor.
2998 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
2999 Constructor<T>[] res;
3000 ReflectionData<T> rd = reflectionData();
3001 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3002 if (res != null) return res;
3003 // No cached value available; request value from VM
3004 if (isInterface()) {
3005 @SuppressWarnings("unchecked")
3006 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3007 res = temporaryRes;
3008 } else {
3009 res = getDeclaredConstructors0(publicOnly);
3010 }
3011 if (publicOnly) {
3012 rd.publicConstructors = res;
3013 } else {
3014 rd.declaredConstructors = res;
3015 }
3016 return res;
3017 }
3018
3019 //
3020 //
3021 // java.lang.reflect.Method handling
3022 //
3023 //
3024
3025 // Returns an array of "root" methods. These Method objects must NOT
3026 // be propagated to the outside world, but must instead be copied
3027 // via ReflectionFactory.copyMethod.
3028 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3029 Method[] res;
3030 ReflectionData<T> rd = reflectionData();
3031 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3032 if (res != null) return res;
3033 // No cached value available; request value from VM
3034 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3035 if (publicOnly) {
3036 rd.declaredPublicMethods = res;
3037 } else {
3038 rd.declaredMethods = res;
3039 }
3040 return res;
3041 }
3042
3043 // Returns an array of "root" methods. These Method objects must NOT
3044 // be propagated to the outside world, but must instead be copied
3045 // via ReflectionFactory.copyMethod.
3046 private Method[] privateGetPublicMethods() {
3047 Method[] res;
3048 ReflectionData<T> rd = reflectionData();
3049 res = rd.publicMethods;
3050 if (res != null) return res;
3051
3052 // No cached value available; compute value recursively.
3053 // Start by fetching public declared methods...
3054 PublicMethods pms = new PublicMethods();
3055 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3056 pms.merge(m);
3057 }
3058 // ...then recur over superclass methods...
3059 Class<?> sc = getSuperclass();
3060 if (sc != null) {
3061 for (Method m : sc.privateGetPublicMethods()) {
3062 pms.merge(m);
3063 }
3064 }
3065 // ...and finally over direct superinterfaces.
3066 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3067 for (Method m : intf.privateGetPublicMethods()) {
3068 // static interface methods are not inherited
3069 if (!Modifier.isStatic(m.getModifiers())) {
3070 pms.merge(m);
3071 }
3072 }
3073 }
3074
3075 res = pms.toArray();
3076 rd.publicMethods = res;
3077 return res;
3078 }
3079
3080
3081 //
3082 // Helpers for fetchers of one field, method, or constructor
3083 //
3084
3085 // This method does not copy the returned Field object!
3086 private static Field searchFields(Field[] fields, String name) {
3087 for (Field field : fields) {
3088 if (field.getName().equals(name)) {
3089 return field;
3090 }
3091 }
3092 return null;
3093 }
3094
3095 // Returns a "root" Field object. This Field object must NOT
3096 // be propagated to the outside world, but must instead be copied
3097 // via ReflectionFactory.copyField.
3098 private Field getField0(String name) {
3099 // Note: the intent is that the search algorithm this routine
3100 // uses be equivalent to the ordering imposed by
3101 // privateGetPublicFields(). It fetches only the declared
3102 // public fields for each class, however, to reduce the number
3103 // of Field objects which have to be created for the common
3104 // case where the field being requested is declared in the
3105 // class which is being queried.
3106 Field res;
3107 // Search declared public fields
3108 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3109 return res;
3110 }
3111 // Direct superinterfaces, recursively
3112 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3113 for (Class<?> c : interfaces) {
3114 if ((res = c.getField0(name)) != null) {
3115 return res;
3116 }
3117 }
3118 // Direct superclass, recursively
3119 if (!isInterface()) {
3120 Class<?> c = getSuperclass();
3121 if (c != null) {
3122 if ((res = c.getField0(name)) != null) {
3123 return res;
3124 }
3125 }
3126 }
3127 return null;
3128 }
3129
3130 // This method does not copy the returned Method object!
3131 private static Method searchMethods(Method[] methods,
3132 String name,
3133 Class<?>[] parameterTypes)
3134 {
3135 ReflectionFactory fact = getReflectionFactory();
3136 Method res = null;
3137 for (Method m : methods) {
3138 if (m.getName().equals(name)
3139 && arrayContentsEq(parameterTypes,
3140 fact.getExecutableSharedParameterTypes(m))
3141 && (res == null
3142 || (res.getReturnType() != m.getReturnType()
3143 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3144 res = m;
3145 }
3146 return res;
3147 }
3148
3149 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3150
3151 // Returns a "root" Method object. This Method object must NOT
3152 // be propagated to the outside world, but must instead be copied
3153 // via ReflectionFactory.copyMethod.
3154 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3155 PublicMethods.MethodList res = getMethodsRecursive(
3156 name,
3157 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3158 /* includeStatic */ true, /* publicOnly */ true);
3159 return res == null ? null : res.getMostSpecific();
3160 }
3161
3162 // Returns a list of "root" Method objects. These Method objects must NOT
3163 // be propagated to the outside world, but must instead be copied
3164 // via ReflectionFactory.copyMethod.
3165 private PublicMethods.MethodList getMethodsRecursive(String name,
3166 Class<?>[] parameterTypes,
3167 boolean includeStatic,
3168 boolean publicOnly) {
3169 // 1st check declared methods
3170 Method[] methods = privateGetDeclaredMethods(publicOnly);
3171 PublicMethods.MethodList res = PublicMethods.MethodList
3172 .filter(methods, name, parameterTypes, includeStatic);
3173 // if there is at least one match among declared methods, we need not
3174 // search any further as such match surely overrides matching methods
3175 // declared in superclass(es) or interface(s).
3176 if (res != null) {
3177 return res;
3178 }
3179
3180 // if there was no match among declared methods,
3181 // we must consult the superclass (if any) recursively...
3182 Class<?> sc = getSuperclass();
3183 if (sc != null) {
3184 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3185 }
3186
3187 // ...and coalesce the superclass methods with methods obtained
3188 // from directly implemented interfaces excluding static methods...
3189 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3190 res = PublicMethods.MethodList.merge(
3191 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3192 }
3193
3194 return res;
3195 }
3196
3197 // Returns a "root" Constructor object. This Constructor object must NOT
3198 // be propagated to the outside world, but must instead be copied
3199 // via ReflectionFactory.copyConstructor.
3200 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3201 int which) throws NoSuchMethodException
3202 {
3203 ReflectionFactory fact = getReflectionFactory();
3204 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3205 for (Constructor<T> constructor : constructors) {
3206 if (arrayContentsEq(parameterTypes,
3207 fact.getExecutableSharedParameterTypes(constructor))) {
3208 return constructor;
3209 }
3210 }
3211 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3212 }
3213
3214 //
3215 // Other helpers and base implementation
3216 //
3217
3218 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3219 if (a1 == null) {
3220 return a2 == null || a2.length == 0;
3221 }
3222
3223 if (a2 == null) {
3224 return a1.length == 0;
3225 }
3226
3227 if (a1.length != a2.length) {
3228 return false;
3229 }
3230
3231 for (int i = 0; i < a1.length; i++) {
3232 if (a1[i] != a2[i]) {
3233 return false;
3234 }
3235 }
3236
3237 return true;
3238 }
3239
3240 private static Field[] copyFields(Field[] arg) {
3241 Field[] out = new Field[arg.length];
3242 ReflectionFactory fact = getReflectionFactory();
3243 for (int i = 0; i < arg.length; i++) {
3244 out[i] = fact.copyField(arg[i]);
3245 }
3246 return out;
3247 }
3248
3249 private static Method[] copyMethods(Method[] arg) {
3250 Method[] out = new Method[arg.length];
3251 ReflectionFactory fact = getReflectionFactory();
3252 for (int i = 0; i < arg.length; i++) {
3253 out[i] = fact.copyMethod(arg[i]);
3254 }
3255 return out;
3256 }
3257
3258 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3259 Constructor<U>[] out = arg.clone();
3260 ReflectionFactory fact = getReflectionFactory();
3261 for (int i = 0; i < out.length; i++) {
3262 out[i] = fact.copyConstructor(out[i]);
3263 }
3264 return out;
3265 }
3266
3267 private native Field[] getDeclaredFields0(boolean publicOnly);
3268 private native Method[] getDeclaredMethods0(boolean publicOnly);
3269 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3270 private native Class<?>[] getDeclaredClasses0();
3271
3272 /*
3273 * Returns an array containing the components of the Record attribute,
3274 * or null if the attribute is not present.
3275 *
3276 * Note that this method returns non-null array on a class with
3277 * the Record attribute even if this class is not a record.
3278 */
3279 private native RecordComponent[] getRecordComponents0();
3280 private native boolean isRecord0();
3281
3282 /**
3283 * Helper method to get the method name from arguments.
3284 */
3285 private String methodToString(String name, Class<?>[] argTypes) {
3286 return getName() + '.' + name +
3287 ((argTypes == null || argTypes.length == 0) ?
3288 "()" :
3289 Arrays.stream(argTypes)
3290 .map(c -> c == null ? "null" : c.getName())
3291 .collect(Collectors.joining(",", "(", ")")));
3292 }
3293
3294 /** use serialVersionUID from JDK 1.1 for interoperability */
3295 @java.io.Serial
3296 private static final long serialVersionUID = 3206093459760846163L;
3297
3298
3299 /**
3300 * Class Class is special cased within the Serialization Stream Protocol.
3301 *
3302 * A Class instance is written initially into an ObjectOutputStream in the
3303 * following format:
3304 * <pre>
3305 * {@code TC_CLASS} ClassDescriptor
3306 * A ClassDescriptor is a special cased serialization of
3307 * a {@code java.io.ObjectStreamClass} instance.
3308 * </pre>
3309 * A new handle is generated for the initial time the class descriptor
3310 * is written into the stream. Future references to the class descriptor
3311 * are written as references to the initial class descriptor instance.
3312 *
3313 * @see java.io.ObjectStreamClass
3314 */
3315 @java.io.Serial
3316 private static final ObjectStreamField[] serialPersistentFields =
3317 new ObjectStreamField[0];
3318
3319
3320 /**
3321 * Returns the assertion status that would be assigned to this
3322 * class if it were to be initialized at the time this method is invoked.
3323 * If this class has had its assertion status set, the most recent
3324 * setting will be returned; otherwise, if any package default assertion
3325 * status pertains to this class, the most recent setting for the most
3326 * specific pertinent package default assertion status is returned;
3327 * otherwise, if this class is not a system class (i.e., it has a
3328 * class loader) its class loader's default assertion status is returned;
3329 * otherwise, the system class default assertion status is returned.
3330 *
3331 * @apiNote
3332 * Few programmers will have any need for this method; it is provided
3333 * for the benefit of the JDK itself. (It allows a class to determine at
3334 * the time that it is initialized whether assertions should be enabled.)
3335 * Note that this method is not guaranteed to return the actual
3336 * assertion status that was (or will be) associated with the specified
3337 * class when it was (or will be) initialized.
3338 *
3339 * @return the desired assertion status of the specified class.
3340 * @see java.lang.ClassLoader#setClassAssertionStatus
3341 * @see java.lang.ClassLoader#setPackageAssertionStatus
3342 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3343 * @since 1.4
3344 */
3345 public boolean desiredAssertionStatus() {
3346 ClassLoader loader = classLoader;
3347 // If the loader is null this is a system class, so ask the VM
3348 if (loader == null)
3349 return desiredAssertionStatus0(this);
3350
3351 // If the classloader has been initialized with the assertion
3352 // directives, ask it. Otherwise, ask the VM.
3353 synchronized(loader.assertionLock) {
3354 if (loader.classAssertionStatus != null) {
3355 return loader.desiredAssertionStatus(getName());
3356 }
3357 }
3358 return desiredAssertionStatus0(this);
3359 }
3360
3361 // Retrieves the desired assertion status of this class from the VM
3362 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3363
3364 /**
3365 * Returns true if and only if this class was declared as an enum in the
3366 * source code.
3367 *
3368 * Note that {@link java.lang.Enum} is not itself an enum class.
3369 *
3370 * Also note that if an enum constant is declared with a class body,
3371 * the class of that enum constant object is an anonymous class
3372 * and <em>not</em> the class of the declaring enum class. The
3373 * {@link Enum#getDeclaringClass} method of an enum constant can
3374 * be used to get the class of the enum class declaring the
3375 * constant.
3376 *
3377 * @return true if and only if this class was declared as an enum in the
3378 * source code
3379 * @since 1.5
3380 * @jls 8.9.1 Enum Constants
3381 */
3382 public boolean isEnum() {
3383 // An enum must both directly extend java.lang.Enum and have
3384 // the ENUM bit set; classes for specialized enum constants
3385 // don't do the former.
3386 return (this.getModifiers() & ENUM) != 0 &&
3387 this.getSuperclass() == java.lang.Enum.class;
3388 }
3389
3390 /**
3391 * Returns {@code true} if and only if this class is a record class.
3392 *
3393 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3394 * class is {@code java.lang.Record}. A record class is {@linkplain
3395 * Modifier#FINAL final}. A record class has (possibly zero) record
3396 * components; {@link #getRecordComponents()} returns a non-null but
3397 * possibly empty value for a record.
3398 *
3399 * <p> Note that class {@link Record} is not a record class and thus
3400 * invoking this method on class {@code Record} returns {@code false}.
3401 *
3402 * @return true if and only if this class is a record class, otherwise false
3403 * @jls 8.10 Record Classes
3404 * @since 16
3405 */
3406 public boolean isRecord() {
3407 // this superclass and final modifier check is not strictly necessary
3408 // they are intrinsified and serve as a fast-path check
3409 return getSuperclass() == java.lang.Record.class &&
3410 (this.getModifiers() & Modifier.FINAL) != 0 &&
3411 isRecord0();
3412 }
3413
3414 // Fetches the factory for reflective objects
3415 private static ReflectionFactory getReflectionFactory() {
3416 var factory = reflectionFactory;
3417 if (factory != null) {
3418 return factory;
3419 }
3420 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3421 }
3422 private static ReflectionFactory reflectionFactory;
3423
3424 /**
3425 * When CDS is enabled, the Class class may be aot-initialized. However,
3426 * we can't archive reflectionFactory, so we reset it to null, so it
3427 * will be allocated again at runtime.
3428 */
3429 private static void resetArchivedStates() {
3430 reflectionFactory = null;
3431 }
3432
3433 /**
3434 * Returns the elements of this enum class or null if this
3435 * Class object does not represent an enum class.
3436 *
3437 * @return an array containing the values comprising the enum class
3438 * represented by this {@code Class} object in the order they're
3439 * declared, or null if this {@code Class} object does not
3440 * represent an enum class
3441 * @since 1.5
3442 * @jls 8.9.1 Enum Constants
3443 */
3444 public T[] getEnumConstants() {
3445 T[] values = getEnumConstantsShared();
3446 return (values != null) ? values.clone() : null;
3447 }
3448
3449 /**
3450 * Returns the elements of this enum class or null if this
3451 * Class object does not represent an enum class;
3452 * identical to getEnumConstants except that the result is
3453 * uncloned, cached, and shared by all callers.
3454 */
3455 T[] getEnumConstantsShared() {
3456 T[] constants = enumConstants;
3457 if (constants == null) {
3458 if (!isEnum()) return null;
3459 try {
3460 final Method values = getMethod("values");
3461 values.setAccessible(true);
3462 @SuppressWarnings("unchecked")
3463 T[] temporaryConstants = (T[])values.invoke(null);
3464 enumConstants = constants = temporaryConstants;
3465 }
3466 // These can happen when users concoct enum-like classes
3467 // that don't comply with the enum spec.
3468 catch (InvocationTargetException | NoSuchMethodException |
3469 IllegalAccessException | NullPointerException |
3470 ClassCastException ex) { return null; }
3471 }
3472 return constants;
3473 }
3474 private transient volatile T[] enumConstants;
3475
3476 /**
3477 * Returns a map from simple name to enum constant. This package-private
3478 * method is used internally by Enum to implement
3479 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3480 * efficiently. Note that the map is returned by this method is
3481 * created lazily on first use. Typically it won't ever get created.
3482 */
3483 Map<String, T> enumConstantDirectory() {
3484 Map<String, T> directory = enumConstantDirectory;
3485 if (directory == null) {
3486 T[] universe = getEnumConstantsShared();
3487 if (universe == null)
3488 throw new IllegalArgumentException(
3489 getName() + " is not an enum class");
3490 directory = HashMap.newHashMap(universe.length);
3491 for (T constant : universe) {
3492 directory.put(((Enum<?>)constant).name(), constant);
3493 }
3494 enumConstantDirectory = directory;
3495 }
3496 return directory;
3497 }
3498 private transient volatile Map<String, T> enumConstantDirectory;
3499
3500 /**
3501 * Casts an object to the class or interface represented
3502 * by this {@code Class} object.
3503 *
3504 * @param obj the object to be cast
3505 * @return the object after casting, or null if obj is null
3506 *
3507 * @throws ClassCastException if the object is not
3508 * null and is not assignable to the type T.
3509 *
3510 * @since 1.5
3511 */
3512 @SuppressWarnings("unchecked")
3513 @IntrinsicCandidate
3514 public T cast(Object obj) {
3515 if (obj != null && !isInstance(obj))
3516 throw new ClassCastException(cannotCastMsg(obj));
3517 return (T) obj;
3518 }
3519
3520 private String cannotCastMsg(Object obj) {
3521 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3522 }
3523
3524 /**
3525 * Casts this {@code Class} object to represent a subclass of the class
3526 * represented by the specified class object. Checks that the cast
3527 * is valid, and throws a {@code ClassCastException} if it is not. If
3528 * this method succeeds, it always returns a reference to this {@code Class} object.
3529 *
3530 * <p>This method is useful when a client needs to "narrow" the type of
3531 * a {@code Class} object to pass it to an API that restricts the
3532 * {@code Class} objects that it is willing to accept. A cast would
3533 * generate a compile-time warning, as the correctness of the cast
3534 * could not be checked at runtime (because generic types are implemented
3535 * by erasure).
3536 *
3537 * @param <U> the type to cast this {@code Class} object to
3538 * @param clazz the class of the type to cast this {@code Class} object to
3539 * @return this {@code Class} object, cast to represent a subclass of
3540 * the specified class object.
3541 * @throws ClassCastException if this {@code Class} object does not
3542 * represent a subclass of the specified class (here "subclass" includes
3543 * the class itself).
3544 * @since 1.5
3545 */
3546 @SuppressWarnings("unchecked")
3547 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3548 if (clazz.isAssignableFrom(this))
3549 return (Class<? extends U>) this;
3550 else
3551 throw new ClassCastException(this.toString());
3552 }
3553
3554 /**
3555 * {@inheritDoc}
3556 * <p>Note that any annotation returned by this method is a
3557 * declaration annotation.
3558 *
3559 * @throws NullPointerException {@inheritDoc}
3560 * @since 1.5
3561 */
3562 @Override
3563 @SuppressWarnings("unchecked")
3564 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3565 Objects.requireNonNull(annotationClass);
3566
3567 return (A) annotationData().annotations.get(annotationClass);
3568 }
3569
3570 /**
3571 * {@inheritDoc}
3572 * @throws NullPointerException {@inheritDoc}
3573 * @since 1.5
3574 */
3575 @Override
3576 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3577 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3578 }
3579
3580 /**
3581 * {@inheritDoc}
3582 * <p>Note that any annotations returned by this method are
3583 * declaration annotations.
3584 *
3585 * @throws NullPointerException {@inheritDoc}
3586 * @since 1.8
3587 */
3588 @Override
3589 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3590 Objects.requireNonNull(annotationClass);
3591
3592 AnnotationData annotationData = annotationData();
3593 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3594 this,
3595 annotationClass);
3596 }
3597
3598 /**
3599 * {@inheritDoc}
3600 * <p>Note that any annotations returned by this method are
3601 * declaration annotations.
3602 *
3603 * @since 1.5
3604 */
3605 @Override
3606 public Annotation[] getAnnotations() {
3607 return AnnotationParser.toArray(annotationData().annotations);
3608 }
3609
3610 /**
3611 * {@inheritDoc}
3612 * <p>Note that any annotation returned by this method is a
3613 * declaration annotation.
3614 *
3615 * @throws NullPointerException {@inheritDoc}
3616 * @since 1.8
3617 */
3618 @Override
3619 @SuppressWarnings("unchecked")
3620 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3621 Objects.requireNonNull(annotationClass);
3622
3623 return (A) annotationData().declaredAnnotations.get(annotationClass);
3624 }
3625
3626 /**
3627 * {@inheritDoc}
3628 * <p>Note that any annotations returned by this method are
3629 * declaration annotations.
3630 *
3631 * @throws NullPointerException {@inheritDoc}
3632 * @since 1.8
3633 */
3634 @Override
3635 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3636 Objects.requireNonNull(annotationClass);
3637
3638 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3639 annotationClass);
3640 }
3641
3642 /**
3643 * {@inheritDoc}
3644 * <p>Note that any annotations returned by this method are
3645 * declaration annotations.
3646 *
3647 * @since 1.5
3648 */
3649 @Override
3650 public Annotation[] getDeclaredAnnotations() {
3651 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3652 }
3653
3654 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3655 private static class AnnotationData {
3656 final Map<Class<? extends Annotation>, Annotation> annotations;
3657 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3658
3659 // Value of classRedefinedCount when we created this AnnotationData instance
3660 final int redefinedCount;
3661
3662 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3663 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3664 int redefinedCount) {
3665 this.annotations = annotations;
3666 this.declaredAnnotations = declaredAnnotations;
3667 this.redefinedCount = redefinedCount;
3668 }
3669 }
3670
3671 // Annotations cache
3672 @SuppressWarnings("UnusedDeclaration")
3673 private transient volatile AnnotationData annotationData;
3674
3675 private AnnotationData annotationData() {
3676 while (true) { // retry loop
3677 AnnotationData annotationData = this.annotationData;
3678 int classRedefinedCount = this.classRedefinedCount;
3679 if (annotationData != null &&
3680 annotationData.redefinedCount == classRedefinedCount) {
3681 return annotationData;
3682 }
3683 // null or stale annotationData -> optimistically create new instance
3684 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3685 // try to install it
3686 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3687 // successfully installed new AnnotationData
3688 return newAnnotationData;
3689 }
3690 }
3691 }
3692
3693 private AnnotationData createAnnotationData(int classRedefinedCount) {
3694 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3695 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3696 Class<?> superClass = getSuperclass();
3697 Map<Class<? extends Annotation>, Annotation> annotations = null;
3698 if (superClass != null) {
3699 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3700 superClass.annotationData().annotations;
3701 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3702 Class<? extends Annotation> annotationClass = e.getKey();
3703 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3704 if (annotations == null) { // lazy construction
3705 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3706 declaredAnnotations.size(),
3707 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3708 )
3709 );
3710 }
3711 annotations.put(annotationClass, e.getValue());
3712 }
3713 }
3714 }
3715 if (annotations == null) {
3716 // no inherited annotations -> share the Map with declaredAnnotations
3717 annotations = declaredAnnotations;
3718 } else {
3719 // at least one inherited annotation -> declared may override inherited
3720 annotations.putAll(declaredAnnotations);
3721 }
3722 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3723 }
3724
3725 // Annotation interfaces cache their internal (AnnotationType) form
3726
3727 @SuppressWarnings("UnusedDeclaration")
3728 private transient volatile AnnotationType annotationType;
3729
3730 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3731 return Atomic.casAnnotationType(this, oldType, newType);
3732 }
3733
3734 AnnotationType getAnnotationType() {
3735 return annotationType;
3736 }
3737
3738 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3739 return annotationData().declaredAnnotations;
3740 }
3741
3742 /* Backing store of user-defined values pertaining to this class.
3743 * Maintained by the ClassValue class.
3744 */
3745 transient ClassValue.ClassValueMap classValueMap;
3746
3747 /**
3748 * Returns an {@code AnnotatedType} object that represents the use of a
3749 * type to specify the superclass of the entity represented by this {@code
3750 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3751 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3752 * Foo.)
3753 *
3754 * <p> If this {@code Class} object represents a class whose declaration
3755 * does not explicitly indicate an annotated superclass, then the return
3756 * value is an {@code AnnotatedType} object representing an element with no
3757 * annotations.
3758 *
3759 * <p> If this {@code Class} represents either the {@code Object} class, an
3760 * interface type, an array type, a primitive type, or void, the return
3761 * value is {@code null}.
3762 *
3763 * @return an object representing the superclass
3764 * @since 1.8
3765 */
3766 public AnnotatedType getAnnotatedSuperclass() {
3767 if (this == Object.class ||
3768 isInterface() ||
3769 isArray() ||
3770 isPrimitive() ||
3771 this == Void.TYPE) {
3772 return null;
3773 }
3774
3775 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3776 }
3777
3778 /**
3779 * Returns an array of {@code AnnotatedType} objects that represent the use
3780 * of types to specify superinterfaces of the entity represented by this
3781 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3782 * superinterface in '... implements Foo' is distinct from the
3783 * <em>declaration</em> of interface Foo.)
3784 *
3785 * <p> If this {@code Class} object represents a class, the return value is
3786 * an array containing objects representing the uses of interface types to
3787 * specify interfaces implemented by the class. The order of the objects in
3788 * the array corresponds to the order of the interface types used in the
3789 * 'implements' clause of the declaration of this {@code Class} object.
3790 *
3791 * <p> If this {@code Class} object represents an interface, the return
3792 * value is an array containing objects representing the uses of interface
3793 * types to specify interfaces directly extended by the interface. The
3794 * order of the objects in the array corresponds to the order of the
3795 * interface types used in the 'extends' clause of the declaration of this
3796 * {@code Class} object.
3797 *
3798 * <p> If this {@code Class} object represents a class or interface whose
3799 * declaration does not explicitly indicate any annotated superinterfaces,
3800 * the return value is an array of length 0.
3801 *
3802 * <p> If this {@code Class} object represents either the {@code Object}
3803 * class, an array type, a primitive type, or void, the return value is an
3804 * array of length 0.
3805 *
3806 * @return an array representing the superinterfaces
3807 * @since 1.8
3808 */
3809 public AnnotatedType[] getAnnotatedInterfaces() {
3810 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3811 }
3812
3813 private native Class<?> getNestHost0();
3814
3815 /**
3816 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3817 * or interface represented by this {@code Class} object belongs.
3818 * Every class and interface belongs to exactly one nest.
3819 *
3820 * If the nest host of this class or interface has previously
3821 * been determined, then this method returns the nest host.
3822 * If the nest host of this class or interface has
3823 * not previously been determined, then this method determines the nest
3824 * host using the algorithm of JVMS 5.4.4, and returns it.
3825 *
3826 * Often, a class or interface belongs to a nest consisting only of itself,
3827 * in which case this method returns {@code this} to indicate that the class
3828 * or interface is the nest host.
3829 *
3830 * <p>If this {@code Class} object represents a primitive type, an array type,
3831 * or {@code void}, then this method returns {@code this},
3832 * indicating that the represented entity belongs to the nest consisting only of
3833 * itself, and is the nest host.
3834 *
3835 * @return the nest host of this class or interface
3836 *
3837 * @since 11
3838 * @jvms 4.7.28 The {@code NestHost} Attribute
3839 * @jvms 4.7.29 The {@code NestMembers} Attribute
3840 * @jvms 5.4.4 Access Control
3841 */
3842 public Class<?> getNestHost() {
3843 if (isPrimitive() || isArray()) {
3844 return this;
3845 }
3846 return getNestHost0();
3847 }
3848
3849 /**
3850 * Determines if the given {@code Class} is a nestmate of the
3851 * class or interface represented by this {@code Class} object.
3852 * Two classes or interfaces are nestmates
3853 * if they have the same {@linkplain #getNestHost() nest host}.
3854 *
3855 * @param c the class to check
3856 * @return {@code true} if this class and {@code c} are members of
3857 * the same nest; and {@code false} otherwise.
3858 *
3859 * @since 11
3860 */
3861 public boolean isNestmateOf(Class<?> c) {
3862 if (this == c) {
3863 return true;
3864 }
3865 if (isPrimitive() || isArray() ||
3866 c.isPrimitive() || c.isArray()) {
3867 return false;
3868 }
3869
3870 return getNestHost() == c.getNestHost();
3871 }
3872
3873 private native Class<?>[] getNestMembers0();
3874
3875 /**
3876 * Returns an array containing {@code Class} objects representing all the
3877 * classes and interfaces that are members of the nest to which the class
3878 * or interface represented by this {@code Class} object belongs.
3879 *
3880 * First, this method obtains the {@linkplain #getNestHost() nest host},
3881 * {@code H}, of the nest to which the class or interface represented by
3882 * this {@code Class} object belongs. The zeroth element of the returned
3883 * array is {@code H}.
3884 *
3885 * Then, for each class or interface {@code C} which is recorded by {@code H}
3886 * as being a member of its nest, this method attempts to obtain the {@code Class}
3887 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3888 * loader} of the current {@code Class} object), and then obtains the
3889 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3890 * The classes and interfaces which are recorded by {@code H} as being members
3891 * of its nest, and for which {@code H} can be determined as their nest host,
3892 * are indicated by subsequent elements of the returned array. The order of
3893 * such elements is unspecified. Duplicates are permitted.
3894 *
3895 * <p>If this {@code Class} object represents a primitive type, an array type,
3896 * or {@code void}, then this method returns a single-element array containing
3897 * {@code this}.
3898 *
3899 * @apiNote
3900 * The returned array includes only the nest members recorded in the {@code NestMembers}
3901 * attribute, and not any hidden classes that were added to the nest via
3902 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3903 * Lookup::defineHiddenClass}.
3904 *
3905 * @return an array of all classes and interfaces in the same nest as
3906 * this class or interface
3907 *
3908 * @since 11
3909 * @see #getNestHost()
3910 * @jvms 4.7.28 The {@code NestHost} Attribute
3911 * @jvms 4.7.29 The {@code NestMembers} Attribute
3912 */
3913 public Class<?>[] getNestMembers() {
3914 if (isPrimitive() || isArray()) {
3915 return new Class<?>[] { this };
3916 }
3917 Class<?>[] members = getNestMembers0();
3918 // Can't actually enable this due to bootstrapping issues
3919 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3920 return members;
3921 }
3922
3923 /**
3924 * Returns the descriptor string of the entity (class, interface, array class,
3925 * primitive type, or {@code void}) represented by this {@code Class} object.
3926 *
3927 * <p> If this {@code Class} object represents a class or interface,
3928 * not an array class, then:
3929 * <ul>
3930 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3931 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3932 * for the class or interface. Calling
3933 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3934 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3935 * describing this class or interface.
3936 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3937 * then the result is a string of the form:
3938 * <blockquote>
3939 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3940 * </blockquote>
3941 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3942 * encoded in internal form indicated by the {@code class} file passed to
3943 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3944 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3945 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3946 * The result string is not a type descriptor.
3947 * </ul>
3948 *
3949 * <p> If this {@code Class} object represents an array class, then
3950 * the result is a string consisting of one or more '{@code [}' characters
3951 * representing the depth of the array nesting, followed by the
3952 * descriptor string of the element type.
3953 * <ul>
3954 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3955 * or interface, then this array class can be described nominally.
3956 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3957 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3958 * describing this array class.
3959 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3960 * interface, then this array class cannot be described nominally.
3961 * The result string is not a type descriptor.
3962 * </ul>
3963 *
3964 * <p> If this {@code Class} object represents a primitive type or
3965 * {@code void}, then the result is a field descriptor string which
3966 * is a one-letter code corresponding to a primitive type or {@code void}
3967 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3968 *
3969 * @return the descriptor string for this {@code Class} object
3970 * @jvms 4.3.2 Field Descriptors
3971 * @since 12
3972 */
3973 @Override
3974 public String descriptorString() {
3975 if (isPrimitive())
3976 return Wrapper.forPrimitiveType(this).basicTypeString();
3977
3978 if (isArray()) {
3979 return "[".concat(componentType.descriptorString());
3980 } else if (isHidden()) {
3981 String name = getName();
3982 int index = name.indexOf('/');
3983 return new StringBuilder(name.length() + 2)
3984 .append('L')
3985 .append(name.substring(0, index).replace('.', '/'))
3986 .append('.')
3987 .append(name, index + 1, name.length())
3988 .append(';')
3989 .toString();
3990 } else {
3991 String name = getName().replace('.', '/');
3992 return StringConcatHelper.concat("L", name, ";");
3993 }
3994 }
3995
3996 /**
3997 * Returns the component type of this {@code Class}, if it describes
3998 * an array type, or {@code null} otherwise.
3999 *
4000 * @implSpec
4001 * Equivalent to {@link Class#getComponentType()}.
4002 *
4003 * @return a {@code Class} describing the component type, or {@code null}
4004 * if this {@code Class} does not describe an array type
4005 * @since 12
4006 */
4007 @Override
4008 public Class<?> componentType() {
4009 return isArray() ? componentType : null;
4010 }
4011
4012 /**
4013 * Returns a {@code Class} for an array type whose component type
4014 * is described by this {@linkplain Class}.
4015 *
4016 * @throws UnsupportedOperationException if this component type is {@linkplain
4017 * Void#TYPE void} or if the number of dimensions of the resulting array
4018 * type would exceed 255.
4019 * @return a {@code Class} describing the array type
4020 * @jvms 4.3.2 Field Descriptors
4021 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4022 * @since 12
4023 */
4024 @Override
4025 public Class<?> arrayType() {
4026 try {
4027 return Array.newInstance(this, 0).getClass();
4028 } catch (IllegalArgumentException iae) {
4029 throw new UnsupportedOperationException(iae);
4030 }
4031 }
4032
4033 /**
4034 * Returns a nominal descriptor for this instance, if one can be
4035 * constructed, or an empty {@link Optional} if one cannot be.
4036 *
4037 * @return An {@link Optional} containing the resulting nominal descriptor,
4038 * or an empty {@link Optional} if one cannot be constructed.
4039 * @since 12
4040 */
4041 @Override
4042 public Optional<ClassDesc> describeConstable() {
4043 Class<?> c = isArray() ? elementType() : this;
4044 return c.isHidden() ? Optional.empty()
4045 : Optional.of(ConstantUtils.classDesc(this));
4046 }
4047
4048 /**
4049 * Returns {@code true} if and only if the underlying class is a hidden class.
4050 *
4051 * @return {@code true} if and only if this class is a hidden class.
4052 *
4053 * @since 15
4054 * @see MethodHandles.Lookup#defineHiddenClass
4055 * @see Class##hiddenClasses Hidden Classes
4056 */
4057 @IntrinsicCandidate
4058 public native boolean isHidden();
4059
4060 /**
4061 * Returns an array containing {@code Class} objects representing the
4062 * direct subinterfaces or subclasses permitted to extend or
4063 * implement this class or interface if it is sealed. The order of such elements
4064 * is unspecified. The array is empty if this sealed class or interface has no
4065 * permitted subclass. If this {@code Class} object represents a primitive type,
4066 * {@code void}, an array type, or a class or interface that is not sealed,
4067 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4068 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4069 * returns a non-null value.
4070 *
4071 * For each class or interface {@code C} which is recorded as a permitted
4072 * direct subinterface or subclass of this class or interface,
4073 * this method attempts to obtain the {@code Class}
4074 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4075 * loader} of the current {@code Class} object).
4076 * The {@code Class} objects which can be obtained and which are direct
4077 * subinterfaces or subclasses of this class or interface,
4078 * are indicated by elements of the returned array. If a {@code Class} object
4079 * cannot be obtained, it is silently ignored, and not included in the result
4080 * array.
4081 *
4082 * @return an array of {@code Class} objects of the permitted subclasses of this class
4083 * or interface, or {@code null} if this class or interface is not sealed.
4084 *
4085 * @jls 8.1 Class Declarations
4086 * @jls 9.1 Interface Declarations
4087 * @since 17
4088 */
4089 public Class<?>[] getPermittedSubclasses() {
4090 Class<?>[] subClasses;
4091 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4092 return null;
4093 }
4094 if (subClasses.length > 0) {
4095 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4096 subClasses = Arrays.stream(subClasses)
4097 .filter(this::isDirectSubType)
4098 .toArray(s -> new Class<?>[s]);
4099 }
4100 }
4101 return subClasses;
4102 }
4103
4104 private boolean isDirectSubType(Class<?> c) {
4105 if (isInterface()) {
4106 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4107 if (i == this) {
4108 return true;
4109 }
4110 }
4111 } else {
4112 return c.getSuperclass() == this;
4113 }
4114 return false;
4115 }
4116
4117 /**
4118 * Returns {@code true} if and only if this {@code Class} object represents
4119 * a sealed class or interface. If this {@code Class} object represents a
4120 * primitive type, {@code void}, or an array type, this method returns
4121 * {@code false}. A sealed class or interface has (possibly zero) permitted
4122 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4123 * possibly empty value for a sealed class or interface.
4124 *
4125 * @return {@code true} if and only if this {@code Class} object represents
4126 * a sealed class or interface.
4127 *
4128 * @jls 8.1 Class Declarations
4129 * @jls 9.1 Interface Declarations
4130 * @since 17
4131 */
4132 public boolean isSealed() {
4133 if (isArray() || isPrimitive()) {
4134 return false;
4135 }
4136 return getPermittedSubclasses() != null;
4137 }
4138
4139 private native Class<?>[] getPermittedSubclasses0();
4140
4141 /*
4142 * Return the class's major and minor class file version packed into an int.
4143 * The high order 16 bits contain the class's minor version. The low order
4144 * 16 bits contain the class's major version.
4145 *
4146 * If the class is an array type then the class file version of its element
4147 * type is returned. If the class is a primitive type then the latest class
4148 * file major version is returned and zero is returned for the minor version.
4149 */
4150 private int getClassFileVersion() {
4151 Class<?> c = isArray() ? elementType() : this;
4152 return c.getClassFileVersion0();
4153 }
4154
4155 private native int getClassFileVersion0();
4156
4157 /*
4158 * Return the access flags as they were in the class's bytecode, including
4159 * the original setting of ACC_SUPER.
4160 *
4161 * If the class is an array type then the access flags of the element type is
4162 * returned. If the class is a primitive then ACC_ABSTRACT | ACC_FINAL | ACC_PUBLIC.
4163 */
4164 private int getClassAccessFlagsRaw() {
4165 Class<?> c = isArray() ? elementType() : this;
4166 return c.getClassAccessFlagsRaw0();
4167 }
4168
4169 private native int getClassAccessFlagsRaw0();
4170
4171 // Support for "OLD" CDS workflow -- {
4172 private static final int RD_PUBLIC_METHODS = (1 << 0);
4173 private static final int RD_PUBLIC_FIELDS = (1 << 1);
4174 private static final int RD_DECLARED_CTORS = (1 << 2);
4175 private static final int RD_PUBLIC_CTORS = (1 << 3);
4176 private static final int RD_DECLARED_METHODS = (1 << 4);
4177 private static final int RD_DECLARED_PUBLIC_METHODS = (1 << 5);
4178 private static final int RD_DECLARED_FIELDS = (1 << 6);
4179 private static final int RD_DECLARED_PUBLIC_FIELDS = (1 << 7);
4180 private static final int RD_DECLARED_INTERFACES = (1 << 8);
4181 private static final int RD_DECLARED_SIMPLE_NAME = (1 << 9);
4182 private static final int RD_DECLARED_CANONICAL_NAME = (1 << 10);
4183 private static final int CLS_NAME = (1 << 10);
4184
4185
4186 private int encodeReflectionData() {
4187 int flags = CLS_NAME;
4188 if (reflectionData != null) {
4189 flags = (reflectionData.publicMethods != null ? RD_PUBLIC_METHODS : 0) |
4190 (reflectionData.publicFields != null ? RD_PUBLIC_FIELDS : 0) |
4191 (reflectionData.declaredConstructors != null ? RD_DECLARED_CTORS : 0) |
4192 (reflectionData.publicConstructors != null ? RD_PUBLIC_CTORS : 0) |
4193 (reflectionData.declaredMethods != null ? RD_DECLARED_METHODS : 0) |
4194 (reflectionData.declaredPublicMethods != null ? RD_DECLARED_PUBLIC_METHODS : 0) |
4195 (reflectionData.declaredFields != null ? RD_DECLARED_FIELDS : 0) |
4196 (reflectionData.declaredPublicFields != null ? RD_DECLARED_PUBLIC_FIELDS : 0) |
4197 (reflectionData.interfaces != null ? RD_DECLARED_INTERFACES : 0) |
4198 (reflectionData.simpleName != null ? RD_DECLARED_SIMPLE_NAME : 0) |
4199 (reflectionData.canonicalName != null ? RD_DECLARED_CANONICAL_NAME : 0);
4200 }
4201 return flags;
4202 }
4203 private void generateReflectionData(int flags) {
4204 if ((flags & CLS_NAME ) != 0) { getName(); } // String name
4205 if ((flags & RD_PUBLIC_METHODS ) != 0) { privateGetPublicMethods(); } // Method[] publicMethods;
4206 if ((flags & RD_PUBLIC_FIELDS ) != 0) { privateGetPublicFields(); } // Field[] publicFields;
4207 if ((flags & RD_DECLARED_CTORS ) != 0) { privateGetDeclaredConstructors(false); } // Constructor<T>[] declaredConstructors;
4208 if ((flags & RD_PUBLIC_CTORS ) != 0) { privateGetDeclaredConstructors(true); } // Constructor<T>[] publicConstructors;
4209 if ((flags & RD_DECLARED_METHODS ) != 0) { privateGetDeclaredMethods(false); } // Method[] declaredMethods;
4210 if ((flags & RD_DECLARED_PUBLIC_METHODS) != 0) { privateGetDeclaredMethods(true); } // Method[] declaredPublicMethods;
4211 if ((flags & RD_DECLARED_FIELDS ) != 0) { privateGetDeclaredFields(false); } // Field[] declaredFields;
4212 if ((flags & RD_DECLARED_PUBLIC_FIELDS ) != 0) { privateGetDeclaredFields(true); } // Field[] declaredPublicFields;
4213 if ((flags & RD_DECLARED_INTERFACES ) != 0) { getInterfaces(false); } // Class<?>[] interfaces;
4214 if ((flags & RD_DECLARED_SIMPLE_NAME ) != 0) { getSimpleName(); } // String simpleName;
4215 if ((flags & RD_DECLARED_CANONICAL_NAME) != 0) { getCanonicalName(); } // String canonicalName;
4216 }
4217
4218 // -- }
4219 }