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.ClassFileFormatVersion;
42 import java.lang.reflect.Constructor;
43 import java.lang.reflect.Executable;
44 import java.lang.reflect.Field;
45 import java.lang.reflect.GenericArrayType;
46 import java.lang.reflect.GenericDeclaration;
47 import java.lang.reflect.InvocationTargetException;
48 import java.lang.reflect.Member;
49 import java.lang.reflect.Method;
50 import java.lang.reflect.Modifier;
51 import java.lang.reflect.RecordComponent;
52 import java.lang.reflect.Type;
53 import java.lang.reflect.TypeVariable;
54 import java.lang.constant.Constable;
55 import java.net.URL;
56 import java.security.AllPermission;
57 import java.security.Permissions;
58 import java.security.ProtectionDomain;
59 import java.util.ArrayList;
60 import java.util.Arrays;
61 import java.util.Collection;
62 import java.util.HashMap;
63 import java.util.HashSet;
64 import java.util.LinkedHashMap;
65 import java.util.LinkedHashSet;
66 import java.util.List;
67 import java.util.Map;
68 import java.util.Objects;
69 import java.util.Optional;
70 import java.util.Set;
71 import java.util.stream.Collectors;
72
73 import jdk.internal.constant.ConstantUtils;
74 import jdk.internal.javac.PreviewFeature;
75 import jdk.internal.loader.BootLoader;
76 import jdk.internal.loader.BuiltinClassLoader;
77 import jdk.internal.misc.PreviewFeatures;
78 import jdk.internal.misc.Unsafe;
79 import jdk.internal.module.Resources;
80 import jdk.internal.reflect.CallerSensitive;
81 import jdk.internal.reflect.CallerSensitiveAdapter;
82 import jdk.internal.reflect.ConstantPool;
83 import jdk.internal.reflect.Reflection;
84 import jdk.internal.reflect.ReflectionFactory;
85 import jdk.internal.vm.annotation.AOTRuntimeSetup;
86 import jdk.internal.vm.annotation.AOTSafeClassInitializer;
87 import jdk.internal.vm.annotation.IntrinsicCandidate;
88 import jdk.internal.vm.annotation.Stable;
89
90 import sun.invoke.util.Wrapper;
91 import sun.reflect.generics.factory.CoreReflectionFactory;
92 import sun.reflect.generics.factory.GenericsFactory;
93 import sun.reflect.generics.repository.ClassRepository;
94 import sun.reflect.generics.repository.MethodRepository;
95 import sun.reflect.generics.repository.ConstructorRepository;
96 import sun.reflect.generics.scope.ClassScope;
97 import sun.reflect.annotation.*;
98
99 /**
100 * Instances of the class {@code Class} represent classes and
101 * interfaces in a running Java application. An enum class and a record
102 * class are kinds of class; an annotation interface is a kind of
103 * interface. Every array also belongs to a class that is reflected as
104 * a {@code Class} object that is shared by all arrays with the same
105 * element type and number of dimensions. The primitive Java types
106 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
107 * int}, {@code long}, {@code float}, and {@code double}), and the
108 * keyword {@code void} are also represented as {@code Class} objects.
109 *
110 * <p> {@code Class} has no public constructor. Instead a {@code Class}
111 * object is constructed automatically by the Java Virtual Machine when
112 * a class is derived from the bytes of a {@code class} file through
113 * the invocation of one of the following methods:
114 * <ul>
115 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
116 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
117 * java.lang.invoke.MethodHandles.Lookup::defineClass}
118 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
119 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
120 * </ul>
121 *
122 * <p> The methods of class {@code Class} expose many characteristics of a
123 * class or interface. Most characteristics are derived from the {@code class}
124 * file that the class loader passed to the Java Virtual Machine or
125 * from the {@code class} file passed to {@code Lookup::defineClass}
126 * or {@code Lookup::defineHiddenClass}.
127 * A few characteristics are determined by the class loading environment
128 * at run time, such as the module returned by {@link #getModule() getModule()}.
129 *
130 * <p> The following example uses a {@code Class} object to print the
131 * class name of an object:
132 *
133 * {@snippet lang="java" :
134 * void printClassName(Object obj) {
135 * System.out.println("The class of " + obj +
136 * " is " + obj.getClass().getName());
137 * }}
138 *
139 * It is also possible to get the {@code Class} object for a named
140 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
141 * (JLS {@jls 15.8.2}).
142 * For example:
143 *
144 * {@snippet lang="java" :
145 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
146 * }
147 *
148 * <p> Some methods of class {@code Class} expose whether the declaration of
149 * a class or interface in Java source code was <em>enclosed</em> within
150 * another declaration. Other methods describe how a class or interface
151 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
152 * classes and interfaces, in the same run-time package, that
153 * allow mutual access to their {@code private} members.
154 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
155 * (JVMS {@jvms 4.7.29}).
156 * One nestmate acts as the
157 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
158 * belong to the nest; each of them in turn records it as the nest host.
159 * The classes and interfaces which belong to a nest, including its host, are
160 * determined when
161 * {@code class} files are generated, for example, a Java compiler
162 * will typically record a top-level class as the host of a nest where the
163 * other members are the classes and interfaces whose declarations are
164 * enclosed within the top-level class declaration.
165 *
166 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
167 * A class or interface created by the invocation of
168 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
169 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
170 * class or interface.
171 * All kinds of class, including enum classes and record classes, may be
172 * hidden classes; all kinds of interface, including annotation interfaces,
173 * may be hidden interfaces.
174 *
175 * The {@linkplain #getName() name of a hidden class or interface} is
176 * not a {@linkplain ClassLoader##binary-name binary name},
177 * which means the following:
178 * <ul>
179 * <li>A hidden class or interface cannot be referenced by the constant pools
180 * of other classes and interfaces.
181 * <li>A hidden class or interface cannot be described in
182 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
183 * {@link #describeConstable() Class::describeConstable},
184 * {@link ClassDesc#of(String) ClassDesc::of}, or
185 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
186 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
187 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
188 * </ul>
189 *
190 * A hidden class or interface is never an array class, but may be
191 * the element type of an array. In all other respects, the fact that
192 * a class or interface is hidden has no bearing on the characteristics
193 * exposed by the methods of class {@code Class}.
194 *
195 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
196 *
197 * Conventionally, a Java compiler, starting from a source file for an
198 * implicitly declared class, say {@code HelloWorld.java}, creates a
199 * similarly-named {@code class} file, {@code HelloWorld.class}, where
200 * the class stored in that {@code class} file is named {@code
201 * "HelloWorld"}, matching the base names of the source and {@code
202 * class} files.
203 *
204 * For the {@code Class} object of an implicitly declared class {@code
205 * HelloWorld}, the methods to get the {@linkplain #getName name} and
206 * {@linkplain #getTypeName type name} return results
207 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
208 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
209 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
210 *
211 * @param <T> the type of the class modeled by this {@code Class}
212 * object. For example, the type of {@code String.class} is {@code
213 * Class<String>}. Use {@code Class<?>} if the class being modeled is
214 * unknown.
215 *
216 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
217 * @since 1.0
218 */
219 @AOTSafeClassInitializer
220 public final class Class<T> implements java.io.Serializable,
221 GenericDeclaration,
222 Type,
223 AnnotatedElement,
224 TypeDescriptor.OfField<Class<?>>,
225 Constable {
226 private static final int ANNOTATION = 0x00002000;
227 private static final int ENUM = 0x00004000;
228 private static final int SYNTHETIC = 0x00001000;
229
230 private static native void registerNatives();
231 static {
232 runtimeSetup();
233 }
234
235 /// No significant static final fields; [#resetArchivedStates()] handles
236 /// prevents storing [#reflectionFactory] into AOT image.
237 @AOTRuntimeSetup
238 private static void runtimeSetup() {
239 registerNatives();
240 }
241
242 /*
243 * Private constructor. Only the Java Virtual Machine creates Class objects.
244 * This constructor is not used and prevents the default constructor being
245 * generated.
246 */
247 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, char flags) {
248 // Initialize final field for classLoader. The initialization value of non-null
249 // prevents future JIT optimizations from assuming this final field is null.
250 // The following assignments are done directly by the VM without calling this constructor.
251 classLoader = loader;
252 componentType = arrayComponentType;
253 modifiers = mods;
254 protectionDomain = pd;
255 primitive = isPrim;
256 classFileAccessFlags = flags;
257 }
258
259 /**
260 * Converts the object to a string. The string representation is the
261 * string "class" or "interface", followed by a space, and then by the
262 * name of the class in the format returned by {@code getName}.
263 * If this {@code Class} object represents a primitive type,
264 * this method returns the name of the primitive type. If
265 * this {@code Class} object represents void this method returns
266 * "void". If this {@code Class} object represents an array type,
267 * this method returns "class " followed by {@code getName}.
268 *
269 * @return a string representation of this {@code Class} object.
270 */
271 public String toString() {
272 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
273 return kind.concat(getName());
274 }
275
276 /**
277 * Returns a string describing this {@code Class}, including
278 * information about modifiers, {@link #isSealed() sealed}/{@code
279 * non-sealed} status, and type parameters.
280 *
281 * The string is formatted as a list of type modifiers, if any,
282 * followed by the kind of type (empty string for primitive types
283 * and {@code class}, {@code enum}, {@code interface},
284 * {@code @interface}, or {@code record} as appropriate), followed
285 * by the type's name, followed by an angle-bracketed
286 * comma-separated list of the type's type parameters, if any,
287 * including informative bounds on the type parameters, if any.
288 *
289 * A space is used to separate modifiers from one another and to
290 * separate any modifiers from the kind of type. The modifiers
291 * occur in canonical order. If there are no type parameters, the
292 * type parameter list is elided.
293 *
294 * For an array type, the string starts with the type name,
295 * followed by an angle-bracketed comma-separated list of the
296 * type's type parameters, if any, followed by a sequence of
297 * {@code []} characters, one set of brackets per dimension of
298 * the array.
299 *
300 * <p>Note that since information about the runtime representation
301 * of a type is being generated, modifiers not present on the
302 * originating source code or illegal on the originating source
303 * code may be present.
304 *
305 * @return a string describing this {@code Class}, including
306 * information about modifiers and type parameters
307 *
308 * @since 1.8
309 */
310 public String toGenericString() {
311 if (isPrimitive()) {
312 return toString();
313 } else {
314 StringBuilder sb = new StringBuilder();
315 Class<?> component = this;
316 int arrayDepth = 0;
317
318 if (isArray()) {
319 do {
320 arrayDepth++;
321 component = component.getComponentType();
322 } while (component.isArray());
323 sb.append(component.getName());
324 } else {
325 // Class modifiers are a superset of interface modifiers
326 int modifiers = getModifiers() & Modifier.classModifiers();
327 // Modifier.toString() below mis-interprets SYNCHRONIZED, STRICT, and VOLATILE bits
328 modifiers &= ~(Modifier.SYNCHRONIZED | Modifier.STRICT | Modifier.VOLATILE);
329 if (modifiers != 0) {
330 sb.append(Modifier.toString(modifiers));
331 sb.append(' ');
332 }
333
334 // A class cannot be strictfp and sealed/non-sealed so
335 // it is sufficient to check for sealed-ness after all
336 // modifiers are printed.
337 addSealingInfo(modifiers, sb);
338
339 if (isAnnotation()) {
340 sb.append('@');
341 }
342 if (isInterface()) { // Note: all annotation interfaces are interfaces
343 sb.append("interface");
344 } else {
345 if (isEnum())
346 sb.append("enum");
347 else {
348 if (isValue()) {
349 sb.append("value ");
350 }
351 if (isRecord())
352 sb.append("record");
353 else
354 sb.append("class");
355 }
356 }
357 sb.append(' ');
358 sb.append(getName());
359 }
360
361 TypeVariable<?>[] typeparms = component.getTypeParameters();
362 if (typeparms.length > 0) {
363 sb.append(Arrays.stream(typeparms)
364 .map(Class::typeVarBounds)
365 .collect(Collectors.joining(",", "<", ">")));
366 }
367
368 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
369
370 return sb.toString();
371 }
372 }
373
374 private void addSealingInfo(int modifiers, StringBuilder sb) {
375 // A class can be final XOR sealed XOR non-sealed.
376 if (Modifier.isFinal(modifiers)) {
377 return; // no-op
378 } else {
379 if (isSealed()) {
380 sb.append("sealed ");
381 return;
382 } else {
383 // Check for sealed ancestor, which implies this class
384 // is non-sealed.
385 if (hasSealedAncestor(this)) {
386 sb.append("non-sealed ");
387 }
388 }
389 }
390 }
391
392 private boolean hasSealedAncestor(Class<?> clazz) {
393 // From JLS 8.1.1.2:
394 // "It is a compile-time error if a class has a sealed direct
395 // superclass or a sealed direct superinterface, and is not
396 // declared final, sealed, or non-sealed either explicitly or
397 // implicitly.
398 // Thus, an effect of the sealed keyword is to force all
399 // direct subclasses to explicitly declare whether they are
400 // final, sealed, or non-sealed. This avoids accidentally
401 // exposing a sealed class hierarchy to unwanted subclassing."
402
403 // Therefore, will just check direct superclass and
404 // superinterfaces.
405 var superclass = clazz.getSuperclass();
406 if (superclass != null && superclass.isSealed()) {
407 return true;
408 }
409 for (var superinterface : clazz.getInterfaces()) {
410 if (superinterface.isSealed()) {
411 return true;
412 }
413 }
414 return false;
415 }
416
417 static String typeVarBounds(TypeVariable<?> typeVar) {
418 Type[] bounds = typeVar.getBounds();
419 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
420 return typeVar.getName();
421 } else {
422 return typeVar.getName() + " extends " +
423 Arrays.stream(bounds)
424 .map(Type::getTypeName)
425 .collect(Collectors.joining(" & "));
426 }
427 }
428
429 /**
430 * Returns the {@code Class} object associated with the class or
431 * interface with the given string name. Invoking this method is
432 * equivalent to:
433 *
434 * {@snippet lang="java" :
435 * Class.forName(className, true, currentLoader)
436 * }
437 *
438 * where {@code currentLoader} denotes the defining class loader of
439 * the current class.
440 *
441 * <p> For example, the following code fragment returns the
442 * runtime {@code Class} object for the class named
443 * {@code java.lang.Thread}:
444 *
445 * {@snippet lang="java" :
446 * Class<?> t = Class.forName("java.lang.Thread");
447 * }
448 * <p>
449 * A call to {@code forName("X")} causes the class named
450 * {@code X} to be initialized.
451 *
452 * <p>
453 * In cases where this method is called from a context where there is no
454 * caller frame on the stack (e.g. when called directly from a JNI
455 * attached thread), the system class loader is used.
456 *
457 * @param className the {@linkplain ClassLoader##binary-name binary name}
458 * of the class or the string representing an array type
459 * @return the {@code Class} object for the class with the
460 * specified name.
461 * @throws LinkageError if the linkage fails
462 * @throws ExceptionInInitializerError if the initialization provoked
463 * by this method fails
464 * @throws ClassNotFoundException if the class cannot be located
465 *
466 * @jls 12.2 Loading of Classes and Interfaces
467 * @jls 12.3 Linking of Classes and Interfaces
468 * @jls 12.4 Initialization of Classes and Interfaces
469 */
470 @CallerSensitive
471 public static Class<?> forName(String className)
472 throws ClassNotFoundException {
473 Class<?> caller = Reflection.getCallerClass();
474 return forName(className, caller);
475 }
476
477 // Caller-sensitive adapter method for reflective invocation
478 @CallerSensitiveAdapter
479 private static Class<?> forName(String className, Class<?> caller)
480 throws ClassNotFoundException {
481 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
482 : ClassLoader.getClassLoader(caller);
483 return forName0(className, true, loader, caller);
484 }
485
486 /**
487 * Returns the {@code Class} object associated with the class or
488 * interface with the given string name, using the given class loader.
489 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
490 * this method attempts to locate and load the class or interface. The specified
491 * class loader is used to load the class or interface. If the parameter
492 * {@code loader} is {@code null}, the class is loaded through the bootstrap
493 * class loader. The class is initialized only if the
494 * {@code initialize} parameter is {@code true} and if it has
495 * not been initialized earlier.
496 *
497 * <p> This method cannot be used to obtain any of the {@code Class} objects
498 * representing primitive types or void, hidden classes or interfaces,
499 * or array classes whose element type is a hidden class or interface.
500 * If {@code name} denotes a primitive type or void, for example {@code I},
501 * an attempt will be made to locate a user-defined class in the unnamed package
502 * whose name is {@code I} instead.
503 * To obtain a {@code Class} object for a named primitive type
504 * such as {@code int} or {@code long} use {@link
505 * #forPrimitiveName(String)}.
506 *
507 * <p> To obtain the {@code Class} object associated with an array class,
508 * the name consists of one or more {@code '['} representing the depth
509 * of the array nesting, followed by the element type as encoded in
510 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
511 *
512 * <p> Examples:
513 * {@snippet lang="java" :
514 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
515 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
516 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
517 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
518 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
519 * }
520 *
521 * <p> A call to {@code getName()} on the {@code Class} object returned
522 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
523 *
524 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
525 * named <i>N</i> to be loaded but not initialized regardless of the value
526 * of the {@code initialize} parameter.
527 *
528 * @apiNote
529 * This method throws errors related to loading, linking or initializing
530 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
531 * <cite>The Java Language Specification</cite>.
532 * In addition, this method does not check whether the requested class
533 * is accessible to its caller.
534 *
535 * @param name the {@linkplain ClassLoader##binary-name binary name}
536 * of the class or the string representing an array class
537 *
538 * @param initialize if {@code true} the class will be initialized
539 * (which implies linking). See Section {@jls
540 * 12.4} of <cite>The Java Language
541 * Specification</cite>.
542 * @param loader class loader from which the class must be loaded
543 * @return class object representing the desired class
544 *
545 * @throws LinkageError if the linkage fails
546 * @throws ExceptionInInitializerError if the initialization provoked
547 * by this method fails
548 * @throws ClassNotFoundException if the class cannot be located by
549 * the specified class loader
550 *
551 * @see java.lang.Class#forName(String)
552 * @see java.lang.ClassLoader
553 *
554 * @jls 12.2 Loading of Classes and Interfaces
555 * @jls 12.3 Linking of Classes and Interfaces
556 * @jls 12.4 Initialization of Classes and Interfaces
557 * @jls 13.1 The Form of a Binary
558 * @since 1.2
559 */
560 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
561 throws ClassNotFoundException
562 {
563 return forName0(name, initialize, loader, null);
564 }
565
566 /** Called after security check for system loader access checks have been made. */
567 private static native Class<?> forName0(String name, boolean initialize,
568 ClassLoader loader,
569 Class<?> caller)
570 throws ClassNotFoundException;
571
572
573 /**
574 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
575 * binary name} in the given module.
576 *
577 * <p> This method attempts to locate and load the class or interface.
578 * It does not link the class, and does not run the class initializer.
579 * If the class is not found, this method returns {@code null}. </p>
580 *
581 * <p> If the class loader of the given module defines other modules and
582 * the given name is a class defined in a different module, this method
583 * returns {@code null} after the class is loaded. </p>
584 *
585 * <p> This method does not check whether the requested class is
586 * accessible to its caller. </p>
587 *
588 * @apiNote
589 * This method does not support loading of array types, unlike
590 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
591 * a binary name. This method returns {@code null} on failure rather than
592 * throwing a {@link ClassNotFoundException}, as is done by
593 * the {@link #forName(String, boolean, ClassLoader)} method.
594 *
595 * @param module A module
596 * @param name The {@linkplain ClassLoader##binary-name binary name}
597 * of the class
598 * @return {@code Class} object of the given name defined in the given module;
599 * {@code null} if not found.
600 *
601 * @throws NullPointerException if the given module or name is {@code null}
602 *
603 * @throws LinkageError if the linkage fails
604 *
605 * @jls 12.2 Loading of Classes and Interfaces
606 * @jls 12.3 Linking of Classes and Interfaces
607 * @since 9
608 */
609 public static Class<?> forName(Module module, String name) {
610 Objects.requireNonNull(module);
611 Objects.requireNonNull(name);
612
613 ClassLoader cl = module.getClassLoader();
614 if (cl != null) {
615 return cl.loadClass(module, name);
616 } else {
617 return BootLoader.loadClass(module, name);
618 }
619 }
620
621 /**
622 * {@return {@code true} if this {@code Class} object represents an identity class,
623 * otherwise {@code false}}
624 *
625 * <ul>
626 * <li>
627 * If this {@code Class} object represents an array type this method returns {@code true}.
628 * <li>
629 * If this {@code Class} object represents an interface, a primitive type,
630 * or {@code void} this method returns {@code false}.
631 * <li>
632 * For all other {@code Class} objects, this method returns {@code true} if either
633 * preview features are disabled or {@linkplain Modifier#IDENTITY} is set in the
634 * {@linkplain #getModifiers() class modifiers}.
635 * </ul>
636 * @see AccessFlag#IDENTITY
637 * @since Valhalla
638 */
639 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true)
640 public boolean isIdentity() {
641 if (isPrimitive()) {
642 return false;
643 } else if (PreviewFeatures.isEnabled()) {
644 return isArray() || Modifier.isIdentity(modifiers);
645 } else {
646 return !isInterface();
647 }
648 }
649
650 /**
651 * {@return {@code true} if this {@code Class} object represents a value class,
652 * otherwise {@code false}}
653 * <ul>
654 * <li>
655 * If this {@code Class} object represents an array type this method returns {@code false}.
656 * <li>
657 * If this {@code Class} object represents an interface, a primitive type,
658 * or {@code void} this method returns {@code true} only if preview features are enabled.
659 * <li>
660 * For all other {@code Class} objects, this method returns {@code true} only if
661 * preview features are enabled and {@linkplain Modifier#IDENTITY} is not set in the
662 * {@linkplain #getModifiers() class modifiers}.
663 * </ul>
664 * @see AccessFlag#IDENTITY
665 * @since Valhalla
666 */
667 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true)
668 public boolean isValue() {
669 if (!PreviewFeatures.isEnabled()) {
670 return false;
671 }
672 return !isIdentity();
673 }
674
675 /**
676 * {@return the {@code Class} object associated with the
677 * {@linkplain #isPrimitive() primitive type} of the given name}
678 * If the argument is not the name of a primitive type, {@code
679 * null} is returned.
680 *
681 * @param primitiveName the name of the primitive type to find
682 *
683 * @throws NullPointerException if the argument is {@code null}
684 *
685 * @jls 4.2 Primitive Types and Values
686 * @jls 15.8.2 Class Literals
687 * @since 22
688 */
689 public static Class<?> forPrimitiveName(String primitiveName) {
690 return switch(primitiveName) {
691 // Integral types
692 case "int" -> int.class;
693 case "long" -> long.class;
694 case "short" -> short.class;
695 case "char" -> char.class;
696 case "byte" -> byte.class;
697
698 // Floating-point types
699 case "float" -> float.class;
700 case "double" -> double.class;
701
702 // Other types
703 case "boolean" -> boolean.class;
704 case "void" -> void.class;
705
706 default -> null;
707 };
708 }
709
710 /**
711 * Creates a new instance of the class represented by this {@code Class}
712 * object. The class is instantiated as if by a {@code new}
713 * expression with an empty argument list. The class is initialized if it
714 * has not already been initialized.
715 *
716 * @deprecated This method propagates any exception thrown by the
717 * nullary constructor, including a checked exception. Use of
718 * this method effectively bypasses the compile-time exception
719 * checking that would otherwise be performed by the compiler.
720 * The {@link
721 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
722 * Constructor.newInstance} method avoids this problem by wrapping
723 * any exception thrown by the constructor in a (checked) {@link
724 * java.lang.reflect.InvocationTargetException}.
725 *
726 * <p>The call
727 *
728 * {@snippet lang="java" :
729 * clazz.newInstance()
730 * }
731 *
732 * can be replaced by
733 *
734 * {@snippet lang="java" :
735 * clazz.getDeclaredConstructor().newInstance()
736 * }
737 *
738 * The latter sequence of calls is inferred to be able to throw
739 * the additional exception types {@link
740 * InvocationTargetException} and {@link
741 * NoSuchMethodException}. Both of these exception types are
742 * subclasses of {@link ReflectiveOperationException}.
743 *
744 * @return a newly allocated instance of the class represented by this
745 * object.
746 * @throws IllegalAccessException if the class or its nullary
747 * constructor is not accessible.
748 * @throws InstantiationException
749 * if this {@code Class} represents an abstract class,
750 * an interface, an array class, a primitive type, or void;
751 * or if the class has no nullary constructor;
752 * or if the instantiation fails for some other reason.
753 * @throws ExceptionInInitializerError if the initialization
754 * provoked by this method fails.
755 */
756 @CallerSensitive
757 @Deprecated(since="9")
758 public T newInstance()
759 throws InstantiationException, IllegalAccessException
760 {
761 // Constructor lookup
762 Constructor<T> tmpConstructor = cachedConstructor;
763 if (tmpConstructor == null) {
764 if (this == Class.class) {
765 throw new IllegalAccessException(
766 "Can not call newInstance() on the Class for java.lang.Class"
767 );
768 }
769 try {
770 Class<?>[] empty = {};
771 final Constructor<T> c = getReflectionFactory().copyConstructor(
772 getConstructor0(empty, Member.DECLARED));
773 // Disable accessibility checks on the constructor
774 // access check is done with the true caller
775 c.setAccessible(true);
776 cachedConstructor = tmpConstructor = c;
777 } catch (NoSuchMethodException e) {
778 throw (InstantiationException)
779 new InstantiationException(getName()).initCause(e);
780 }
781 }
782
783 try {
784 Class<?> caller = Reflection.getCallerClass();
785 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
786 } catch (InvocationTargetException e) {
787 Unsafe.getUnsafe().throwException(e.getTargetException());
788 // Not reached
789 return null;
790 }
791 }
792
793 private transient volatile Constructor<T> cachedConstructor;
794
795 /**
796 * Determines if the specified {@code Object} is assignment-compatible
797 * with the object represented by this {@code Class}. This method is
798 * the dynamic equivalent of the Java language {@code instanceof}
799 * operator. The method returns {@code true} if the specified
800 * {@code Object} argument is non-null and can be cast to the
801 * reference type represented by this {@code Class} object without
802 * raising a {@code ClassCastException.} It returns {@code false}
803 * otherwise.
804 *
805 * <p> Specifically, if this {@code Class} object represents a
806 * declared class, this method returns {@code true} if the specified
807 * {@code Object} argument is an instance of the represented class (or
808 * of any of its subclasses); it returns {@code false} otherwise. If
809 * this {@code Class} object represents an array class, this method
810 * returns {@code true} if the specified {@code Object} argument
811 * can be converted to an object of the array class by an identity
812 * conversion or by a widening reference conversion; it returns
813 * {@code false} otherwise. If this {@code Class} object
814 * represents an interface, this method returns {@code true} if the
815 * class or any superclass of the specified {@code Object} argument
816 * implements this interface; it returns {@code false} otherwise. If
817 * this {@code Class} object represents a primitive type, this method
818 * returns {@code false}.
819 *
820 * @param obj the object to check
821 * @return true if {@code obj} is an instance of this class
822 *
823 * @since 1.1
824 */
825 @IntrinsicCandidate
826 public native boolean isInstance(Object obj);
827
828
829 /**
830 * Determines if the class or interface represented by this
831 * {@code Class} object is either the same as, or is a superclass or
832 * superinterface of, the class or interface represented by the specified
833 * {@code Class} parameter. It returns {@code true} if so;
834 * otherwise it returns {@code false}. If this {@code Class}
835 * object represents a primitive type, this method returns
836 * {@code true} if the specified {@code Class} parameter is
837 * exactly this {@code Class} object; otherwise it returns
838 * {@code false}.
839 *
840 * <p> Specifically, this method tests whether the type represented by the
841 * specified {@code Class} parameter can be converted to the type
842 * represented by this {@code Class} object via an identity conversion
843 * or via a widening reference conversion. See <cite>The Java Language
844 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
845 * for details.
846 *
847 * @param cls the {@code Class} object to be checked
848 * @return the {@code boolean} value indicating whether objects of the
849 * type {@code cls} can be assigned to objects of this class
850 * @throws NullPointerException if the specified Class parameter is
851 * null.
852 * @since 1.1
853 */
854 @IntrinsicCandidate
855 public native boolean isAssignableFrom(Class<?> cls);
856
857
858 /**
859 * Determines if this {@code Class} object represents an
860 * interface type.
861 *
862 * @return {@code true} if this {@code Class} object represents an interface;
863 * {@code false} otherwise.
864 */
865 public boolean isInterface() {
866 return Modifier.isInterface(modifiers);
867 }
868
869
870 /**
871 * Determines if this {@code Class} object represents an array class.
872 *
873 * @return {@code true} if this {@code Class} object represents an array class;
874 * {@code false} otherwise.
875 * @since 1.1
876 */
877 public boolean isArray() {
878 return componentType != null;
879 }
880
881
882 /**
883 * Determines if this {@code Class} object represents a primitive
884 * type or void.
885 *
886 * <p> There are nine predefined {@code Class} objects to
887 * represent the eight primitive types and void. These are
888 * created by the Java Virtual Machine, and have the same
889 * {@linkplain #getName() names} as the primitive types that they
890 * represent, namely {@code boolean}, {@code byte}, {@code char},
891 * {@code short}, {@code int}, {@code long}, {@code float}, and
892 * {@code double}.
893 *
894 * <p>No other class objects are considered primitive.
895 *
896 * @apiNote
897 * A {@code Class} object represented by a primitive type can be
898 * accessed via the {@code TYPE} public static final variables
899 * defined in the primitive wrapper classes such as {@link
900 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
901 * language, the objects may be referred to by a class literal
902 * expression such as {@code int.class}. The {@code Class} object
903 * for void can be expressed as {@code void.class} or {@link
904 * java.lang.Void#TYPE Void.TYPE}.
905 *
906 * @return true if and only if this class represents a primitive type
907 *
908 * @see java.lang.Boolean#TYPE
909 * @see java.lang.Character#TYPE
910 * @see java.lang.Byte#TYPE
911 * @see java.lang.Short#TYPE
912 * @see java.lang.Integer#TYPE
913 * @see java.lang.Long#TYPE
914 * @see java.lang.Float#TYPE
915 * @see java.lang.Double#TYPE
916 * @see java.lang.Void#TYPE
917 * @since 1.1
918 * @jls 15.8.2 Class Literals
919 */
920 public boolean isPrimitive() {
921 return primitive;
922 }
923
924 /**
925 * Returns true if this {@code Class} object represents an annotation
926 * interface. Note that if this method returns true, {@link #isInterface()}
927 * would also return true, as all annotation interfaces are also interfaces.
928 *
929 * @return {@code true} if this {@code Class} object represents an annotation
930 * interface; {@code false} otherwise
931 * @since 1.5
932 */
933 public boolean isAnnotation() {
934 return (getModifiers() & ANNOTATION) != 0;
935 }
936
937 /**
938 *{@return {@code true} if and only if this class has the synthetic modifier
939 * bit set}
940 *
941 * @jls 13.1 The Form of a Binary
942 * @jvms 4.1 The {@code ClassFile} Structure
943 * @see <a
944 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
945 * programming language and JVM modeling in core reflection</a>
946 * @since 1.5
947 */
948 public boolean isSynthetic() {
949 return (getModifiers() & SYNTHETIC) != 0;
950 }
951
952 /**
953 * Returns the name of the entity (class, interface, array class,
954 * primitive type, or void) represented by this {@code Class} object.
955 *
956 * <p> If this {@code Class} object represents a class or interface,
957 * not an array class, then:
958 * <ul>
959 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
960 * then the {@linkplain ClassLoader##binary-name binary name}
961 * of the class or interface is returned.
962 * <li> If the class or interface is hidden, then the result is a string
963 * of the form: {@code N + '/' + <suffix>}
964 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
965 * indicated by the {@code class} file passed to
966 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
967 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
968 * </ul>
969 *
970 * <p> If this {@code Class} object represents an array class, then
971 * the result is a string consisting of one or more '{@code [}' characters
972 * representing the depth of the array nesting, followed by the element
973 * type as encoded using the following table:
974 *
975 * <blockquote><table class="striped" id="nameFormat">
976 * <caption style="display:none">Element types and encodings</caption>
977 * <thead>
978 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
979 * </thead>
980 * <tbody style="text-align:left">
981 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
982 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
983 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
984 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
985 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
986 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
987 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
988 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
989 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
990 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
991 * </tbody>
992 * </table></blockquote>
993 *
994 * <p> If this {@code Class} object represents a primitive type or {@code void},
995 * then the result is a string with the same spelling as the Java language
996 * keyword which corresponds to the primitive type or {@code void}.
997 *
998 * <p> Examples:
999 * <blockquote><pre>
1000 * String.class.getName()
1001 * returns "java.lang.String"
1002 * Character.UnicodeBlock.class.getName()
1003 * returns "java.lang.Character$UnicodeBlock"
1004 * byte.class.getName()
1005 * returns "byte"
1006 * (new Object[3]).getClass().getName()
1007 * returns "[Ljava.lang.Object;"
1008 * (new int[3][4][5][6][7][8][9]).getClass().getName()
1009 * returns "[[[[[[[I"
1010 * </pre></blockquote>
1011 *
1012 * @apiNote
1013 * Distinct class objects can have the same name but different class loaders.
1014 *
1015 * @return the name of the class, interface, or other entity
1016 * represented by this {@code Class} object.
1017 * @jls 13.1 The Form of a Binary
1018 */
1019 public String getName() {
1020 String name = this.name;
1021 return name != null ? name : initClassName();
1022 }
1023
1024 // Cache the name to reduce the number of calls into the VM.
1025 // This field would be set by VM itself during initClassName call.
1026 private transient String name;
1027 private native String initClassName();
1028
1029 /**
1030 * Returns the class loader for the class. Some implementations may use
1031 * null to represent the bootstrap class loader. This method will return
1032 * null in such implementations if this class was loaded by the bootstrap
1033 * class loader.
1034 *
1035 * <p>If this {@code Class} object
1036 * represents a primitive type or void, null is returned.
1037 *
1038 * @return the class loader that loaded the class or interface
1039 * represented by this {@code Class} object.
1040 * @see java.lang.ClassLoader
1041 */
1042 public ClassLoader getClassLoader() {
1043 return classLoader;
1044 }
1045
1046 // Package-private to allow ClassLoader access
1047 ClassLoader getClassLoader0() { return classLoader; }
1048
1049 /**
1050 * Returns the module that this class or interface is a member of.
1051 *
1052 * If this class represents an array type then this method returns the
1053 * {@code Module} for the element type. If this class represents a
1054 * primitive type or void, then the {@code Module} object for the
1055 * {@code java.base} module is returned.
1056 *
1057 * If this class is in an unnamed module then the {@linkplain
1058 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1059 * loader for this class is returned.
1060 *
1061 * @return the module that this class or interface is a member of
1062 *
1063 * @since 9
1064 */
1065 public Module getModule() {
1066 return module;
1067 }
1068
1069 // set by VM
1070 @Stable
1071 private transient Module module;
1072
1073 // Initialized in JVM not by private constructor
1074 // This field is filtered from reflection access, i.e. getDeclaredField
1075 // will throw NoSuchFieldException
1076 private final ClassLoader classLoader;
1077
1078 private transient Object classData; // Set by VM
1079 private transient Object[] signers; // Read by VM, mutable
1080 private final transient char modifiers; // Set by the VM
1081 private final transient char classFileAccessFlags; // Set by the VM
1082 private final transient boolean primitive; // Set by the VM if the Class is a primitive type.
1083
1084 // package-private
1085 Object getClassData() {
1086 return classData;
1087 }
1088
1089 /**
1090 * Returns an array of {@code TypeVariable} objects that represent the
1091 * type variables declared by the generic declaration represented by this
1092 * {@code GenericDeclaration} object, in declaration order. Returns an
1093 * array of length 0 if the underlying generic declaration declares no type
1094 * variables.
1095 *
1096 * @return an array of {@code TypeVariable} objects that represent
1097 * the type variables declared by this generic declaration
1098 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1099 * signature of this generic declaration does not conform to
1100 * the format specified in section {@jvms 4.7.9} of
1101 * <cite>The Java Virtual Machine Specification</cite>
1102 * @since 1.5
1103 */
1104 @SuppressWarnings("unchecked")
1105 public TypeVariable<Class<T>>[] getTypeParameters() {
1106 ClassRepository info = getGenericInfo();
1107 if (info != null)
1108 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1109 else
1110 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1111 }
1112
1113
1114 /**
1115 * Returns the {@code Class} representing the direct superclass of the
1116 * entity (class, interface, primitive type or void) represented by
1117 * this {@code Class}. If this {@code Class} represents either the
1118 * {@code Object} class, an interface, a primitive type, or void, then
1119 * null is returned. If this {@code Class} object represents an array class
1120 * then the {@code Class} object representing the {@code Object} class is
1121 * returned.
1122 *
1123 * @return the direct superclass of the class represented by this {@code Class} object
1124 */
1125 @IntrinsicCandidate
1126 public native Class<? super T> getSuperclass();
1127
1128
1129 /**
1130 * Returns the {@code Type} representing the direct superclass of
1131 * the entity (class, interface, primitive type or void) represented by
1132 * this {@code Class} object.
1133 *
1134 * <p>If the superclass is a parameterized type, the {@code Type}
1135 * object returned must accurately reflect the actual type
1136 * arguments used in the source code. The parameterized type
1137 * representing the superclass is created if it had not been
1138 * created before. See the declaration of {@link
1139 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1140 * semantics of the creation process for parameterized types. If
1141 * this {@code Class} object represents either the {@code Object}
1142 * class, an interface, a primitive type, or void, then null is
1143 * returned. If this {@code Class} object represents an array class
1144 * then the {@code Class} object representing the {@code Object} class is
1145 * returned.
1146 *
1147 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1148 * class signature does not conform to the format specified in
1149 * section {@jvms 4.7.9} of <cite>The Java Virtual
1150 * Machine Specification</cite>
1151 * @throws TypeNotPresentException if the generic superclass
1152 * refers to a non-existent type declaration
1153 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1154 * generic superclass refers to a parameterized type that cannot be
1155 * instantiated for any reason
1156 * @return the direct superclass of the class represented by this {@code Class} object
1157 * @since 1.5
1158 */
1159 public Type getGenericSuperclass() {
1160 ClassRepository info = getGenericInfo();
1161 if (info == null) {
1162 return getSuperclass();
1163 }
1164
1165 // Historical irregularity:
1166 // Generic signature marks interfaces with superclass = Object
1167 // but this API returns null for interfaces
1168 if (isInterface()) {
1169 return null;
1170 }
1171
1172 return info.getSuperclass();
1173 }
1174
1175 /**
1176 * Gets the package of this class.
1177 *
1178 * <p>If this class represents an array type, a primitive type or void,
1179 * this method returns {@code null}.
1180 *
1181 * @return the package of this class.
1182 */
1183 public Package getPackage() {
1184 if (isPrimitive() || isArray()) {
1185 return null;
1186 }
1187 ClassLoader cl = classLoader;
1188 return cl != null ? cl.definePackage(this)
1189 : BootLoader.definePackage(this);
1190 }
1191
1192 /**
1193 * Returns the fully qualified package name.
1194 *
1195 * <p> If this class is a top level class, then this method returns the fully
1196 * qualified name of the package that the class is a member of, or the
1197 * empty string if the class is in an unnamed package.
1198 *
1199 * <p> If this class is a member class, then this method is equivalent to
1200 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1201 * enclosing class}.
1202 *
1203 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1204 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1205 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1206 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1207 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1208 *
1209 * <p> If this class represents an array type then this method returns the
1210 * package name of the element type. If this class represents a primitive
1211 * type or void then the package name "{@code java.lang}" is returned.
1212 *
1213 * @return the fully qualified package name
1214 *
1215 * @since 9
1216 * @jls 6.7 Fully Qualified Names and Canonical Names
1217 */
1218 public String getPackageName() {
1219 String pn = this.packageName;
1220 if (pn == null) {
1221 Class<?> c = isArray() ? elementType() : this;
1222 if (c.isPrimitive()) {
1223 pn = "java.lang";
1224 } else {
1225 String cn = c.getName();
1226 int dot = cn.lastIndexOf('.');
1227 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1228 }
1229 this.packageName = pn;
1230 }
1231 return pn;
1232 }
1233
1234 // cached package name
1235 private transient String packageName;
1236
1237 /**
1238 * Returns the interfaces directly implemented by the class or interface
1239 * represented by this {@code Class} object.
1240 *
1241 * <p>If this {@code Class} object represents a class, the return value is an array
1242 * containing objects representing all interfaces directly implemented by
1243 * the class. The order of the interface objects in the array corresponds
1244 * to the order of the interface names in the {@code implements} clause of
1245 * the declaration of the class represented by this {@code Class} object. For example,
1246 * given the declaration:
1247 * <blockquote>
1248 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1249 * </blockquote>
1250 * suppose the value of {@code s} is an instance of
1251 * {@code Shimmer}; the value of the expression:
1252 * <blockquote>
1253 * {@code s.getClass().getInterfaces()[0]}
1254 * </blockquote>
1255 * is the {@code Class} object that represents interface
1256 * {@code FloorWax}; and the value of:
1257 * <blockquote>
1258 * {@code s.getClass().getInterfaces()[1]}
1259 * </blockquote>
1260 * is the {@code Class} object that represents interface
1261 * {@code DessertTopping}.
1262 *
1263 * <p>If this {@code Class} object represents an interface, the array contains objects
1264 * representing all interfaces directly extended by the interface. The
1265 * order of the interface objects in the array corresponds to the order of
1266 * the interface names in the {@code extends} clause of the declaration of
1267 * the interface represented by this {@code Class} object.
1268 *
1269 * <p>If this {@code Class} object represents a class or interface that implements no
1270 * interfaces, the method returns an array of length 0.
1271 *
1272 * <p>If this {@code Class} object represents a primitive type or void, the method
1273 * returns an array of length 0.
1274 *
1275 * <p>If this {@code Class} object represents an array type, the
1276 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1277 * returned in that order.
1278 *
1279 * @return an array of interfaces directly implemented by this class
1280 */
1281 public Class<?>[] getInterfaces() {
1282 // defensively copy before handing over to user code
1283 return getInterfaces(true);
1284 }
1285
1286 private Class<?>[] getInterfaces(boolean cloneArray) {
1287 ReflectionData<T> rd = reflectionData();
1288 Class<?>[] interfaces = rd.interfaces;
1289 if (interfaces == null) {
1290 interfaces = getInterfaces0();
1291 rd.interfaces = interfaces;
1292 }
1293 // defensively copy if requested
1294 return cloneArray ? interfaces.clone() : interfaces;
1295 }
1296
1297 private native Class<?>[] getInterfaces0();
1298
1299 /**
1300 * Returns the {@code Type}s representing the interfaces
1301 * directly implemented by the class or interface represented by
1302 * this {@code Class} object.
1303 *
1304 * <p>If a superinterface is a parameterized type, the
1305 * {@code Type} object returned for it must accurately reflect
1306 * the actual type arguments used in the source code. The
1307 * parameterized type representing each superinterface is created
1308 * if it had not been created before. See the declaration of
1309 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1310 * for the semantics of the creation process for parameterized
1311 * types.
1312 *
1313 * <p>If this {@code Class} object represents a class, the return value is an array
1314 * containing objects representing all interfaces directly implemented by
1315 * the class. The order of the interface objects in the array corresponds
1316 * to the order of the interface names in the {@code implements} clause of
1317 * the declaration of the class represented by this {@code Class} object.
1318 *
1319 * <p>If this {@code Class} object represents an interface, the array contains objects
1320 * representing all interfaces directly extended by the interface. The
1321 * order of the interface objects in the array corresponds to the order of
1322 * the interface names in the {@code extends} clause of the declaration of
1323 * the interface represented by this {@code Class} object.
1324 *
1325 * <p>If this {@code Class} object represents a class or interface that implements no
1326 * interfaces, the method returns an array of length 0.
1327 *
1328 * <p>If this {@code Class} object represents a primitive type or void, the method
1329 * returns an array of length 0.
1330 *
1331 * <p>If this {@code Class} object represents an array type, the
1332 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1333 * returned in that order.
1334 *
1335 * @throws java.lang.reflect.GenericSignatureFormatError
1336 * if the generic class signature does not conform to the
1337 * format specified in section {@jvms 4.7.9} of <cite>The
1338 * Java Virtual Machine Specification</cite>
1339 * @throws TypeNotPresentException if any of the generic
1340 * superinterfaces refers to a non-existent type declaration
1341 * @throws java.lang.reflect.MalformedParameterizedTypeException
1342 * if any of the generic superinterfaces refer to a parameterized
1343 * type that cannot be instantiated for any reason
1344 * @return an array of interfaces directly implemented by this class
1345 * @since 1.5
1346 */
1347 public Type[] getGenericInterfaces() {
1348 ClassRepository info = getGenericInfo();
1349 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1350 }
1351
1352
1353 /**
1354 * Returns the {@code Class} representing the component type of an
1355 * array. If this class does not represent an array class this method
1356 * returns null.
1357 *
1358 * @return the {@code Class} representing the component type of this
1359 * class if this class is an array
1360 * @see java.lang.reflect.Array
1361 * @since 1.1
1362 */
1363 public Class<?> getComponentType() {
1364 return componentType;
1365 }
1366
1367 // The componentType field's null value is the sole indication that the class
1368 // is an array - see isArray().
1369 private transient final Class<?> componentType;
1370
1371 /*
1372 * Returns the {@code Class} representing the element type of an array class.
1373 * If this class does not represent an array class, then this method returns
1374 * {@code null}.
1375 */
1376 private Class<?> elementType() {
1377 if (!isArray()) return null;
1378
1379 Class<?> c = this;
1380 while (c.isArray()) {
1381 c = c.getComponentType();
1382 }
1383 return c;
1384 }
1385
1386 /**
1387 * Returns the Java language modifiers for this class or interface, encoded
1388 * in an integer. The modifiers consist of the Java Virtual Machine's
1389 * constants for {@code public}, {@code protected},
1390 * {@code private}, {@code final}, {@code static},
1391 * {@code abstract} and {@code interface}; they should be decoded
1392 * using the methods of class {@code Modifier}.
1393 *
1394 * <p> If the underlying class is an array class:
1395 * <ul>
1396 * <li> its {@code public}, {@code private} and {@code protected}
1397 * modifiers are the same as those of its component type
1398 * <li> its {@code abstract} and {@code final} modifiers are always
1399 * {@code true}
1400 * <li> its interface modifier is always {@code false}, even when
1401 * the component type is an interface
1402 * <li> its {@code identity} modifier is always true
1403 * </ul>
1404 * If this {@code Class} object represents a primitive type or
1405 * void, its {@code public}, {@code abstract}, and {@code final}
1406 * modifiers are always {@code true}.
1407 * For {@code Class} objects representing void, primitive types, and
1408 * arrays, the values of other modifiers are {@code false} other
1409 * than as specified above.
1410 *
1411 * <p> The modifier encodings are defined in section {@jvms 4.1}
1412 * of <cite>The Java Virtual Machine Specification</cite>.
1413 *
1414 * @return the {@code int} representing the modifiers for this class
1415 * @see java.lang.reflect.Modifier
1416 * @see #accessFlags()
1417 * @see <a
1418 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1419 * programming language and JVM modeling in core reflection</a>
1420 * @since 1.1
1421 * @jls 8.1.1 Class Modifiers
1422 * @jls 9.1.1 Interface Modifiers
1423 * @jvms 4.1 The {@code ClassFile} Structure
1424 */
1425 public int getModifiers() { return modifiers; }
1426
1427 /**
1428 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1429 * flags} for this class, possibly empty}
1430 * The {@code AccessFlags} may depend on the class file format version of the class.
1431 *
1432 * <p> If the underlying class is an array class:
1433 * <ul>
1434 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1435 * access flags are the same as those of its component type
1436 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1437 * <li> its {@code INTERFACE} flag is absent, even when the
1438 * component type is an interface
1439 * <li> its {@code identity} modifier is always true
1440 * </ul>
1441 * If this {@code Class} object represents a primitive type or
1442 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1443 * {@code FINAL}.
1444 * For {@code Class} objects representing void, primitive types, and
1445 * arrays, access flags are absent other than as specified above.
1446 *
1447 * @see #getModifiers()
1448 * @jvms 4.1 The ClassFile Structure
1449 * @jvms 4.7.6 The InnerClasses Attribute
1450 * @since 20
1451 */
1452 public Set<AccessFlag> accessFlags() {
1453 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1454 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1455 // and STATIC, which are not allowed on Location.CLASS.
1456 // Use getClassFileAccessFlags to expose SUPER status.
1457 // Arrays need to use PRIVATE/PROTECTED from its component modifiers.
1458 var location = (isMemberClass() || isLocalClass() ||
1459 isAnonymousClass() || isArray()) ?
1460 AccessFlag.Location.INNER_CLASS :
1461 AccessFlag.Location.CLASS;
1462 int accessFlags = location == AccessFlag.Location.CLASS ? getClassFileAccessFlags() : getModifiers();
1463 var reflectionFactory = getReflectionFactory();
1464 var ans = reflectionFactory.parseAccessFlags(accessFlags, location, this);
1465 if (PreviewFeatures.isEnabled() && reflectionFactory.classFileFormatVersion(this) != ClassFileFormatVersion.CURRENT_PREVIEW_FEATURES
1466 && isIdentity()) {
1467 var set = new HashSet<>(ans);
1468 set.add(AccessFlag.IDENTITY);
1469 return Set.copyOf(set);
1470 }
1471 return ans;
1472 }
1473
1474 /**
1475 * Gets the signers of this class.
1476 *
1477 * @return the signers of this class, or null if there are no signers. In
1478 * particular, this method returns null if this {@code Class} object represents
1479 * a primitive type or void.
1480 * @since 1.1
1481 */
1482
1483 public Object[] getSigners() {
1484 var signers = this.signers;
1485 return signers == null ? null : signers.clone();
1486 }
1487
1488 /**
1489 * Set the signers of this class.
1490 */
1491 void setSigners(Object[] signers) {
1492 if (!isPrimitive() && !isArray()) {
1493 this.signers = signers;
1494 }
1495 }
1496
1497 /**
1498 * If this {@code Class} object represents a local or anonymous
1499 * class within a method, returns a {@link
1500 * java.lang.reflect.Method Method} object representing the
1501 * immediately enclosing method of the underlying class. Returns
1502 * {@code null} otherwise.
1503 *
1504 * In particular, this method returns {@code null} if the underlying
1505 * class is a local or anonymous class immediately enclosed by a class or
1506 * interface declaration, instance initializer or static initializer.
1507 *
1508 * @return the immediately enclosing method of the underlying class, if
1509 * that class is a local or anonymous class; otherwise {@code null}.
1510 *
1511 * @since 1.5
1512 */
1513 public Method getEnclosingMethod() {
1514 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1515
1516 if (enclosingInfo == null)
1517 return null;
1518 else {
1519 if (!enclosingInfo.isMethod())
1520 return null;
1521
1522 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1523 getFactory());
1524 Class<?> returnType = toClass(typeInfo.getReturnType());
1525 Type [] parameterTypes = typeInfo.getParameterTypes();
1526 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1527
1528 // Convert Types to Classes; returned types *should*
1529 // be class objects since the methodDescriptor's used
1530 // don't have generics information
1531 for(int i = 0; i < parameterClasses.length; i++)
1532 parameterClasses[i] = toClass(parameterTypes[i]);
1533
1534 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1535 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1536
1537 /*
1538 * Loop over all declared methods; match method name,
1539 * number of and type of parameters, *and* return
1540 * type. Matching return type is also necessary
1541 * because of covariant returns, etc.
1542 */
1543 ReflectionFactory fact = getReflectionFactory();
1544 for (Method m : candidates) {
1545 if (m.getName().equals(enclosingInfo.getName()) &&
1546 arrayContentsEq(parameterClasses,
1547 fact.getExecutableSharedParameterTypes(m))) {
1548 // finally, check return type
1549 if (m.getReturnType().equals(returnType)) {
1550 return fact.copyMethod(m);
1551 }
1552 }
1553 }
1554
1555 throw new InternalError("Enclosing method not found");
1556 }
1557 }
1558
1559 private native Object[] getEnclosingMethod0();
1560
1561 private EnclosingMethodInfo getEnclosingMethodInfo() {
1562 Object[] enclosingInfo = getEnclosingMethod0();
1563 if (enclosingInfo == null)
1564 return null;
1565 else {
1566 return new EnclosingMethodInfo(enclosingInfo);
1567 }
1568 }
1569
1570 private static final class EnclosingMethodInfo {
1571 private final Class<?> enclosingClass;
1572 private final String name;
1573 private final String descriptor;
1574
1575 static void validate(Object[] enclosingInfo) {
1576 if (enclosingInfo.length != 3)
1577 throw new InternalError("Malformed enclosing method information");
1578 try {
1579 // The array is expected to have three elements:
1580
1581 // the immediately enclosing class
1582 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1583 assert(enclosingClass != null);
1584
1585 // the immediately enclosing method or constructor's
1586 // name (can be null).
1587 String name = (String)enclosingInfo[1];
1588
1589 // the immediately enclosing method or constructor's
1590 // descriptor (null iff name is).
1591 String descriptor = (String)enclosingInfo[2];
1592 assert((name != null && descriptor != null) || name == descriptor);
1593 } catch (ClassCastException cce) {
1594 throw new InternalError("Invalid type in enclosing method information", cce);
1595 }
1596 }
1597
1598 EnclosingMethodInfo(Object[] enclosingInfo) {
1599 validate(enclosingInfo);
1600 this.enclosingClass = (Class<?>)enclosingInfo[0];
1601 this.name = (String)enclosingInfo[1];
1602 this.descriptor = (String)enclosingInfo[2];
1603 }
1604
1605 boolean isPartial() {
1606 return enclosingClass == null || name == null || descriptor == null;
1607 }
1608
1609 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1610
1611 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1612
1613 Class<?> getEnclosingClass() { return enclosingClass; }
1614
1615 String getName() { return name; }
1616
1617 String getDescriptor() { return descriptor; }
1618
1619 }
1620
1621 private static Class<?> toClass(Type o) {
1622 if (o instanceof GenericArrayType gat)
1623 return toClass(gat.getGenericComponentType()).arrayType();
1624 return (Class<?>)o;
1625 }
1626
1627 /**
1628 * If this {@code Class} object represents a local or anonymous
1629 * class within a constructor, returns a {@link
1630 * java.lang.reflect.Constructor Constructor} object representing
1631 * the immediately enclosing constructor of the underlying
1632 * class. Returns {@code null} otherwise. In particular, this
1633 * method returns {@code null} if the underlying class is a local
1634 * or anonymous class immediately enclosed by a class or
1635 * interface declaration, instance initializer or static initializer.
1636 *
1637 * @return the immediately enclosing constructor of the underlying class, if
1638 * that class is a local or anonymous class; otherwise {@code null}.
1639 *
1640 * @since 1.5
1641 */
1642 public Constructor<?> getEnclosingConstructor() {
1643 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1644
1645 if (enclosingInfo == null)
1646 return null;
1647 else {
1648 if (!enclosingInfo.isConstructor())
1649 return null;
1650
1651 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1652 getFactory());
1653 Type [] parameterTypes = typeInfo.getParameterTypes();
1654 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1655
1656 // Convert Types to Classes; returned types *should*
1657 // be class objects since the methodDescriptor's used
1658 // don't have generics information
1659 for (int i = 0; i < parameterClasses.length; i++)
1660 parameterClasses[i] = toClass(parameterTypes[i]);
1661
1662
1663 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1664 Constructor<?>[] candidates = enclosingCandidate
1665 .privateGetDeclaredConstructors(false);
1666 /*
1667 * Loop over all declared constructors; match number
1668 * of and type of parameters.
1669 */
1670 ReflectionFactory fact = getReflectionFactory();
1671 for (Constructor<?> c : candidates) {
1672 if (arrayContentsEq(parameterClasses,
1673 fact.getExecutableSharedParameterTypes(c))) {
1674 return fact.copyConstructor(c);
1675 }
1676 }
1677
1678 throw new InternalError("Enclosing constructor not found");
1679 }
1680 }
1681
1682
1683 /**
1684 * If the class or interface represented by this {@code Class} object
1685 * is a member of another class, returns the {@code Class} object
1686 * representing the class in which it was declared. This method returns
1687 * null if this class or interface is not a member of any other class. If
1688 * this {@code Class} object represents an array class, a primitive
1689 * type, or void, then this method returns null.
1690 *
1691 * @return the declaring class for this class
1692 * @since 1.1
1693 */
1694 public Class<?> getDeclaringClass() {
1695 return getDeclaringClass0();
1696 }
1697
1698 private native Class<?> getDeclaringClass0();
1699
1700
1701 /**
1702 * Returns the immediately enclosing class of the underlying
1703 * class. If the underlying class is a top level class this
1704 * method returns {@code null}.
1705 * @return the immediately enclosing class of the underlying class
1706 * @since 1.5
1707 */
1708 public Class<?> getEnclosingClass() {
1709 // There are five kinds of classes (or interfaces):
1710 // a) Top level classes
1711 // b) Nested classes (static member classes)
1712 // c) Inner classes (non-static member classes)
1713 // d) Local classes (named classes declared within a method)
1714 // e) Anonymous classes
1715
1716
1717 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1718 // attribute if and only if it is a local class or an
1719 // anonymous class.
1720 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1721 Class<?> enclosingCandidate;
1722
1723 if (enclosingInfo == null) {
1724 // This is a top level or a nested class or an inner class (a, b, or c)
1725 enclosingCandidate = getDeclaringClass0();
1726 } else {
1727 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1728 // This is a local class or an anonymous class (d or e)
1729 if (enclosingClass == this || enclosingClass == null)
1730 throw new InternalError("Malformed enclosing method information");
1731 else
1732 enclosingCandidate = enclosingClass;
1733 }
1734 return enclosingCandidate;
1735 }
1736
1737 /**
1738 * Returns the simple name of the underlying class as given in the
1739 * source code. An empty string is returned if the underlying class is
1740 * {@linkplain #isAnonymousClass() anonymous}.
1741 * A {@linkplain #isSynthetic() synthetic class}, one not present
1742 * in source code, can have a non-empty name including special
1743 * characters, such as "{@code $}".
1744 *
1745 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1746 * component type with "[]" appended. In particular the simple
1747 * name of an array class whose component type is anonymous is "[]".
1748 *
1749 * @return the simple name of the underlying class
1750 * @since 1.5
1751 */
1752 public String getSimpleName() {
1753 ReflectionData<T> rd = reflectionData();
1754 String simpleName = rd.simpleName;
1755 if (simpleName == null) {
1756 rd.simpleName = simpleName = getSimpleName0();
1757 }
1758 return simpleName;
1759 }
1760
1761 private String getSimpleName0() {
1762 if (isArray()) {
1763 return getComponentType().getSimpleName().concat("[]");
1764 }
1765 String simpleName = getSimpleBinaryName();
1766 if (simpleName == null) { // top level class
1767 simpleName = getName();
1768 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1769 }
1770 return simpleName;
1771 }
1772
1773 /**
1774 * Return an informative string for the name of this class or interface.
1775 *
1776 * @return an informative string for the name of this class or interface
1777 * @since 1.8
1778 */
1779 public String getTypeName() {
1780 if (isArray()) {
1781 try {
1782 Class<?> cl = this;
1783 int dimensions = 0;
1784 do {
1785 dimensions++;
1786 cl = cl.getComponentType();
1787 } while (cl.isArray());
1788 return cl.getName().concat("[]".repeat(dimensions));
1789 } catch (Throwable e) { /*FALLTHRU*/ }
1790 }
1791 return getName();
1792 }
1793
1794 /**
1795 * Returns the canonical name of the underlying class as
1796 * defined by <cite>The Java Language Specification</cite>.
1797 * Returns {@code null} if the underlying class does not have a canonical
1798 * name. Classes without canonical names include:
1799 * <ul>
1800 * <li>a {@linkplain #isLocalClass() local class}
1801 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1802 * <li>a {@linkplain #isHidden() hidden class}
1803 * <li>an array whose component type does not have a canonical name</li>
1804 * </ul>
1805 *
1806 * The canonical name for a primitive class is the keyword for the
1807 * corresponding primitive type ({@code byte}, {@code short},
1808 * {@code char}, {@code int}, and so on).
1809 *
1810 * <p>An array type has a canonical name if and only if its
1811 * component type has a canonical name. When an array type has a
1812 * canonical name, it is equal to the canonical name of the
1813 * component type followed by "{@code []}".
1814 *
1815 * @return the canonical name of the underlying class if it exists, and
1816 * {@code null} otherwise.
1817 * @jls 6.7 Fully Qualified Names and Canonical Names
1818 * @since 1.5
1819 */
1820 public String getCanonicalName() {
1821 ReflectionData<T> rd = reflectionData();
1822 String canonicalName = rd.canonicalName;
1823 if (canonicalName == null) {
1824 rd.canonicalName = canonicalName = getCanonicalName0();
1825 }
1826 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1827 }
1828
1829 private String getCanonicalName0() {
1830 if (isArray()) {
1831 String canonicalName = getComponentType().getCanonicalName();
1832 if (canonicalName != null)
1833 return canonicalName.concat("[]");
1834 else
1835 return ReflectionData.NULL_SENTINEL;
1836 }
1837 if (isHidden() || isLocalOrAnonymousClass())
1838 return ReflectionData.NULL_SENTINEL;
1839 Class<?> enclosingClass = getEnclosingClass();
1840 if (enclosingClass == null) { // top level class
1841 return getName();
1842 } else {
1843 String enclosingName = enclosingClass.getCanonicalName();
1844 if (enclosingName == null)
1845 return ReflectionData.NULL_SENTINEL;
1846 String simpleName = getSimpleName();
1847 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1848 .append(enclosingName)
1849 .append('.')
1850 .append(simpleName)
1851 .toString();
1852 }
1853 }
1854
1855 /**
1856 * Returns {@code true} if and only if the underlying class
1857 * is an anonymous class.
1858 *
1859 * @apiNote
1860 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1861 *
1862 * @return {@code true} if and only if this class is an anonymous class.
1863 * @since 1.5
1864 * @jls 15.9.5 Anonymous Class Declarations
1865 */
1866 public boolean isAnonymousClass() {
1867 return !isArray() && isLocalOrAnonymousClass() &&
1868 getSimpleBinaryName0() == null;
1869 }
1870
1871 /**
1872 * Returns {@code true} if and only if the underlying class
1873 * is a local class.
1874 *
1875 * @return {@code true} if and only if this class is a local class.
1876 * @since 1.5
1877 * @jls 14.3 Local Class and Interface Declarations
1878 */
1879 public boolean isLocalClass() {
1880 return isLocalOrAnonymousClass() &&
1881 (isArray() || getSimpleBinaryName0() != null);
1882 }
1883
1884 /**
1885 * Returns {@code true} if and only if the underlying class
1886 * is a member class.
1887 *
1888 * @return {@code true} if and only if this class is a member class.
1889 * @since 1.5
1890 * @jls 8.5 Member Class and Interface Declarations
1891 */
1892 public boolean isMemberClass() {
1893 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1894 }
1895
1896 /**
1897 * Returns the "simple binary name" of the underlying class, i.e.,
1898 * the binary name without the leading enclosing class name.
1899 * Returns {@code null} if the underlying class is a top level
1900 * class.
1901 */
1902 private String getSimpleBinaryName() {
1903 if (isTopLevelClass())
1904 return null;
1905 String name = getSimpleBinaryName0();
1906 if (name == null) // anonymous class
1907 return "";
1908 return name;
1909 }
1910
1911 private native String getSimpleBinaryName0();
1912
1913 /**
1914 * Returns {@code true} if this is a top level class. Returns {@code false}
1915 * otherwise.
1916 */
1917 private boolean isTopLevelClass() {
1918 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1919 }
1920
1921 /**
1922 * Returns {@code true} if this is a local class or an anonymous
1923 * class. Returns {@code false} otherwise.
1924 */
1925 private boolean isLocalOrAnonymousClass() {
1926 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1927 // attribute if and only if it is a local class or an
1928 // anonymous class.
1929 return hasEnclosingMethodInfo();
1930 }
1931
1932 private boolean hasEnclosingMethodInfo() {
1933 Object[] enclosingInfo = getEnclosingMethod0();
1934 if (enclosingInfo != null) {
1935 EnclosingMethodInfo.validate(enclosingInfo);
1936 return true;
1937 }
1938 return false;
1939 }
1940
1941 /**
1942 * Returns an array containing {@code Class} objects representing all
1943 * the public classes and interfaces that are members of the class
1944 * represented by this {@code Class} object. This includes public
1945 * class and interface members inherited from superclasses and public class
1946 * and interface members declared by the class. This method returns an
1947 * array of length 0 if this {@code Class} object has no public member
1948 * classes or interfaces. This method also returns an array of length 0 if
1949 * this {@code Class} object represents a primitive type, an array
1950 * class, or void.
1951 *
1952 * @return the array of {@code Class} objects representing the public
1953 * members of this class
1954 * @since 1.1
1955 */
1956 public Class<?>[] getClasses() {
1957 List<Class<?>> list = new ArrayList<>();
1958 Class<?> currentClass = Class.this;
1959 while (currentClass != null) {
1960 for (Class<?> m : currentClass.getDeclaredClasses()) {
1961 if (Modifier.isPublic(m.getModifiers())) {
1962 list.add(m);
1963 }
1964 }
1965 currentClass = currentClass.getSuperclass();
1966 }
1967 return list.toArray(new Class<?>[0]);
1968 }
1969
1970
1971 /**
1972 * Returns an array containing {@code Field} objects reflecting all
1973 * the accessible public fields of the class or interface represented by
1974 * this {@code Class} object.
1975 *
1976 * <p> If this {@code Class} object represents a class or interface with
1977 * no accessible public fields, then this method returns an array of length
1978 * 0.
1979 *
1980 * <p> If this {@code Class} object represents a class, then this method
1981 * returns the public fields of the class and of all its superclasses and
1982 * superinterfaces.
1983 *
1984 * <p> If this {@code Class} object represents an interface, then this
1985 * method returns the fields of the interface and of all its
1986 * superinterfaces.
1987 *
1988 * <p> If this {@code Class} object represents an array type, a primitive
1989 * type, or void, then this method returns an array of length 0.
1990 *
1991 * <p> The elements in the returned array are not sorted and are not in any
1992 * particular order.
1993 *
1994 * @return the array of {@code Field} objects representing the
1995 * public fields
1996 *
1997 * @since 1.1
1998 * @jls 8.2 Class Members
1999 * @jls 8.3 Field Declarations
2000 */
2001 public Field[] getFields() {
2002 return copyFields(privateGetPublicFields());
2003 }
2004
2005
2006 /**
2007 * Returns an array containing {@code Method} objects reflecting all the
2008 * public methods of the class or interface represented by this {@code
2009 * Class} object, including those declared by the class or interface and
2010 * those inherited from superclasses and superinterfaces.
2011 *
2012 * <p> If this {@code Class} object represents an array type, then the
2013 * returned array has a {@code Method} object for each of the public
2014 * methods inherited by the array type from {@code Object}. It does not
2015 * contain a {@code Method} object for {@code clone()}.
2016 *
2017 * <p> If this {@code Class} object represents an interface then the
2018 * returned array does not contain any implicitly declared methods from
2019 * {@code Object}. Therefore, if no methods are explicitly declared in
2020 * this interface or any of its superinterfaces then the returned array
2021 * has length 0. (Note that a {@code Class} object which represents a class
2022 * always has public methods, inherited from {@code Object}.)
2023 *
2024 * <p> The returned array never contains methods with names {@value
2025 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2026 *
2027 * <p> The elements in the returned array are not sorted and are not in any
2028 * particular order.
2029 *
2030 * <p> Generally, the result is computed as with the following 4 step algorithm.
2031 * Let C be the class or interface represented by this {@code Class} object:
2032 * <ol>
2033 * <li> A union of methods is composed of:
2034 * <ol type="a">
2035 * <li> C's declared public instance and static methods as returned by
2036 * {@link #getDeclaredMethods()} and filtered to include only public
2037 * methods.</li>
2038 * <li> If C is a class other than {@code Object}, then include the result
2039 * of invoking this algorithm recursively on the superclass of C.</li>
2040 * <li> Include the results of invoking this algorithm recursively on all
2041 * direct superinterfaces of C, but include only instance methods.</li>
2042 * </ol></li>
2043 * <li> Union from step 1 is partitioned into subsets of methods with same
2044 * signature (name, parameter types) and return type.</li>
2045 * <li> Within each such subset only the most specific methods are selected.
2046 * Let method M be a method from a set of methods with same signature
2047 * and return type. M is most specific if there is no such method
2048 * N != M from the same set, such that N is more specific than M.
2049 * N is more specific than M if:
2050 * <ol type="a">
2051 * <li> N is declared by a class and M is declared by an interface; or</li>
2052 * <li> N and M are both declared by classes or both by interfaces and
2053 * N's declaring type is the same as or a subtype of M's declaring type
2054 * (clearly, if M's and N's declaring types are the same type, then
2055 * M and N are the same method).</li>
2056 * </ol></li>
2057 * <li> The result of this algorithm is the union of all selected methods from
2058 * step 3.</li>
2059 * </ol>
2060 *
2061 * @apiNote There may be more than one method with a particular name
2062 * and parameter types in a class because while the Java language forbids a
2063 * class to declare multiple methods with the same signature but different
2064 * return types, the Java virtual machine does not. This
2065 * increased flexibility in the virtual machine can be used to
2066 * implement various language features. For example, covariant
2067 * returns can be implemented with {@linkplain
2068 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2069 * method and the overriding method would have the same
2070 * signature but different return types.
2071 *
2072 * @return the array of {@code Method} objects representing the
2073 * public methods of this class
2074 *
2075 * @jls 8.2 Class Members
2076 * @jls 8.4 Method Declarations
2077 * @since 1.1
2078 */
2079 public Method[] getMethods() {
2080 return copyMethods(privateGetPublicMethods());
2081 }
2082
2083
2084 /**
2085 * Returns an array containing {@code Constructor} objects reflecting
2086 * all the public constructors of the class represented by this
2087 * {@code Class} object. An array of length 0 is returned if the
2088 * class has no public constructors, or if the class is an array class, or
2089 * if the class reflects a primitive type or void.
2090 *
2091 * @apiNote
2092 * While this method returns an array of {@code
2093 * Constructor<T>} objects (that is an array of constructors from
2094 * this class), the return type of this method is {@code
2095 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2096 * might be expected. This less informative return type is
2097 * necessary since after being returned from this method, the
2098 * array could be modified to hold {@code Constructor} objects for
2099 * different classes, which would violate the type guarantees of
2100 * {@code Constructor<T>[]}.
2101 *
2102 * @return the array of {@code Constructor} objects representing the
2103 * public constructors of this class
2104 *
2105 * @see #getDeclaredConstructors()
2106 * @since 1.1
2107 */
2108 public Constructor<?>[] getConstructors() {
2109 return copyConstructors(privateGetDeclaredConstructors(true));
2110 }
2111
2112
2113 /**
2114 * Returns a {@code Field} object that reflects the specified public member
2115 * field of the class or interface represented by this {@code Class}
2116 * object. The {@code name} parameter is a {@code String} specifying the
2117 * simple name of the desired field.
2118 *
2119 * <p> The field to be reflected is determined by the algorithm that
2120 * follows. Let C be the class or interface represented by this {@code Class} object:
2121 *
2122 * <OL>
2123 * <LI> If C declares a public field with the name specified, that is the
2124 * field to be reflected.</LI>
2125 * <LI> If no field was found in step 1 above, this algorithm is applied
2126 * recursively to each direct superinterface of C. The direct
2127 * superinterfaces are searched in the order they were declared.</LI>
2128 * <LI> If no field was found in steps 1 and 2 above, and C has a
2129 * superclass S, then this algorithm is invoked recursively upon S.
2130 * If C has no superclass, then a {@code NoSuchFieldException}
2131 * is thrown.</LI>
2132 * </OL>
2133 *
2134 * <p> If this {@code Class} object represents an array type, then this
2135 * method does not find the {@code length} field of the array type.
2136 *
2137 * @param name the field name
2138 * @return the {@code Field} object of this class specified by
2139 * {@code name}
2140 * @throws NoSuchFieldException if a field with the specified name is
2141 * not found.
2142 * @throws NullPointerException if {@code name} is {@code null}
2143 *
2144 * @since 1.1
2145 * @jls 8.2 Class Members
2146 * @jls 8.3 Field Declarations
2147 */
2148 public Field getField(String name) throws NoSuchFieldException {
2149 Objects.requireNonNull(name);
2150 Field field = getField0(name);
2151 if (field == null) {
2152 throw new NoSuchFieldException(name);
2153 }
2154 return getReflectionFactory().copyField(field);
2155 }
2156
2157
2158 /**
2159 * Returns a {@code Method} object that reflects the specified public
2160 * member method of the class or interface represented by this
2161 * {@code Class} object. The {@code name} parameter is a
2162 * {@code String} specifying the simple name of the desired method. The
2163 * {@code parameterTypes} parameter is an array of {@code Class}
2164 * objects that identify the method's formal parameter types, in declared
2165 * order. If {@code parameterTypes} is {@code null}, it is
2166 * treated as if it were an empty array.
2167 *
2168 * <p> If this {@code Class} object represents an array type, then this
2169 * method finds any public method inherited by the array type from
2170 * {@code Object} except method {@code clone()}.
2171 *
2172 * <p> If this {@code Class} object represents an interface then this
2173 * method does not find any implicitly declared method from
2174 * {@code Object}. Therefore, if no methods are explicitly declared in
2175 * this interface or any of its superinterfaces, then this method does not
2176 * find any method.
2177 *
2178 * <p> This method does not find any method with name {@value
2179 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2180 *
2181 * <p> Generally, the method to be reflected is determined by the 4 step
2182 * algorithm that follows.
2183 * Let C be the class or interface represented by this {@code Class} object:
2184 * <ol>
2185 * <li> A union of methods is composed of:
2186 * <ol type="a">
2187 * <li> C's declared public instance and static methods as returned by
2188 * {@link #getDeclaredMethods()} and filtered to include only public
2189 * methods that match given {@code name} and {@code parameterTypes}</li>
2190 * <li> If C is a class other than {@code Object}, then include the result
2191 * of invoking this algorithm recursively on the superclass of C.</li>
2192 * <li> Include the results of invoking this algorithm recursively on all
2193 * direct superinterfaces of C, but include only instance methods.</li>
2194 * </ol></li>
2195 * <li> This union is partitioned into subsets of methods with same
2196 * return type (the selection of methods from step 1 also guarantees that
2197 * they have the same method name and parameter types).</li>
2198 * <li> Within each such subset only the most specific methods are selected.
2199 * Let method M be a method from a set of methods with same VM
2200 * signature (return type, name, parameter types).
2201 * M is most specific if there is no such method N != M from the same
2202 * set, such that N is more specific than M. N is more specific than M
2203 * if:
2204 * <ol type="a">
2205 * <li> N is declared by a class and M is declared by an interface; or</li>
2206 * <li> N and M are both declared by classes or both by interfaces and
2207 * N's declaring type is the same as or a subtype of M's declaring type
2208 * (clearly, if M's and N's declaring types are the same type, then
2209 * M and N are the same method).</li>
2210 * </ol></li>
2211 * <li> The result of this algorithm is chosen arbitrarily from the methods
2212 * with most specific return type among all selected methods from step 3.
2213 * Let R be a return type of a method M from the set of all selected methods
2214 * from step 3. M is a method with most specific return type if there is
2215 * no such method N != M from the same set, having return type S != R,
2216 * such that S is a subtype of R as determined by
2217 * R.class.{@link #isAssignableFrom}(S.class).
2218 * </ol>
2219 *
2220 * @apiNote There may be more than one method with matching name and
2221 * parameter types in a class because while the Java language forbids a
2222 * class to declare multiple methods with the same signature but different
2223 * return types, the Java virtual machine does not. This
2224 * increased flexibility in the virtual machine can be used to
2225 * implement various language features. For example, covariant
2226 * returns can be implemented with {@linkplain
2227 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2228 * method and the overriding method would have the same
2229 * signature but different return types. This method would return the
2230 * overriding method as it would have a more specific return type.
2231 *
2232 * @param name the name of the method
2233 * @param parameterTypes the list of parameters
2234 * @return the {@code Method} object that matches the specified
2235 * {@code name} and {@code parameterTypes}
2236 * @throws NoSuchMethodException if a matching method is not found
2237 * or if the name is {@value ConstantDescs#INIT_NAME} or
2238 * {@value ConstantDescs#CLASS_INIT_NAME}.
2239 * @throws NullPointerException if {@code name} is {@code null}
2240 *
2241 * @jls 8.2 Class Members
2242 * @jls 8.4 Method Declarations
2243 * @since 1.1
2244 */
2245 public Method getMethod(String name, Class<?>... parameterTypes)
2246 throws NoSuchMethodException {
2247 Objects.requireNonNull(name);
2248 Method method = getMethod0(name, parameterTypes);
2249 if (method == null) {
2250 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2251 }
2252 return getReflectionFactory().copyMethod(method);
2253 }
2254
2255 /**
2256 * Returns a {@code Constructor} object that reflects the specified
2257 * public constructor of the class represented by this {@code Class}
2258 * object. The {@code parameterTypes} parameter is an array of
2259 * {@code Class} objects that identify the constructor's formal
2260 * parameter types, in declared order.
2261 *
2262 * If this {@code Class} object represents an inner class
2263 * declared in a non-static context, the formal parameter types
2264 * include the explicit enclosing instance as the first parameter.
2265 *
2266 * <p> The constructor to reflect is the public constructor of the class
2267 * represented by this {@code Class} object whose formal parameter
2268 * types match those specified by {@code parameterTypes}.
2269 *
2270 * @param parameterTypes the parameter array
2271 * @return the {@code Constructor} object of the public constructor that
2272 * matches the specified {@code parameterTypes}
2273 * @throws NoSuchMethodException if a matching constructor is not found,
2274 * including when this {@code Class} object represents
2275 * an interface, a primitive type, an array class, or void.
2276 *
2277 * @see #getDeclaredConstructor(Class[])
2278 * @since 1.1
2279 */
2280 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2281 throws NoSuchMethodException {
2282 return getReflectionFactory().copyConstructor(
2283 getConstructor0(parameterTypes, Member.PUBLIC));
2284 }
2285
2286
2287 /**
2288 * Returns an array of {@code Class} objects reflecting all the
2289 * classes and interfaces declared as members of the class represented by
2290 * this {@code Class} object. This includes public, protected, default
2291 * (package) access, and private classes and interfaces declared by the
2292 * class, but excludes inherited classes and interfaces. This method
2293 * returns an array of length 0 if the class declares no classes or
2294 * interfaces as members, or if this {@code Class} object represents a
2295 * primitive type, an array class, or void.
2296 *
2297 * @return the array of {@code Class} objects representing all the
2298 * declared members of this class
2299 *
2300 * @since 1.1
2301 * @jls 8.5 Member Class and Interface Declarations
2302 */
2303 public Class<?>[] getDeclaredClasses() {
2304 return getDeclaredClasses0();
2305 }
2306
2307
2308 /**
2309 * Returns an array of {@code Field} objects reflecting all the fields
2310 * declared by the class or interface represented by this
2311 * {@code Class} object. This includes public, protected, default
2312 * (package) access, and private fields, but excludes inherited fields.
2313 *
2314 * <p> If this {@code Class} object represents a class or interface with no
2315 * declared fields, then this method returns an array of length 0.
2316 *
2317 * <p> If this {@code Class} object represents an array type, a primitive
2318 * type, or void, then this method returns an array of length 0.
2319 *
2320 * <p> The elements in the returned array are not sorted and are not in any
2321 * particular order.
2322 *
2323 * @return the array of {@code Field} objects representing all the
2324 * declared fields of this class
2325 *
2326 * @since 1.1
2327 * @jls 8.2 Class Members
2328 * @jls 8.3 Field Declarations
2329 */
2330 public Field[] getDeclaredFields() {
2331 return copyFields(privateGetDeclaredFields(false));
2332 }
2333
2334 /**
2335 * Returns an array of {@code RecordComponent} objects representing all the
2336 * record components of this record class, or {@code null} if this class is
2337 * not a record class.
2338 *
2339 * <p> The components are returned in the same order that they are declared
2340 * in the record header. The array is empty if this record class has no
2341 * components. If the class is not a record class, that is {@link
2342 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2343 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2344 * returns a non-null value.
2345 *
2346 * @apiNote
2347 * <p> The following method can be used to find the record canonical constructor:
2348 *
2349 * {@snippet lang="java" :
2350 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2351 * throws NoSuchMethodException {
2352 * Class<?>[] paramTypes =
2353 * Arrays.stream(cls.getRecordComponents())
2354 * .map(RecordComponent::getType)
2355 * .toArray(Class<?>[]::new);
2356 * return cls.getDeclaredConstructor(paramTypes);
2357 * }}
2358 *
2359 * @return An array of {@code RecordComponent} objects representing all the
2360 * record components of this record class, or {@code null} if this
2361 * class is not a record class
2362 *
2363 * @jls 8.10 Record Classes
2364 * @since 16
2365 */
2366 public RecordComponent[] getRecordComponents() {
2367 if (!isRecord()) {
2368 return null;
2369 }
2370 return getRecordComponents0();
2371 }
2372
2373 /**
2374 * Returns an array containing {@code Method} objects reflecting all the
2375 * declared methods of the class or interface represented by this {@code
2376 * Class} object, including public, protected, default (package)
2377 * access, and private methods, but excluding inherited methods.
2378 * The declared methods may include methods <em>not</em> in the
2379 * source of the class or interface, including {@linkplain
2380 * Method#isBridge bridge methods} and other {@linkplain
2381 * Executable#isSynthetic synthetic} methods added by compilers.
2382 *
2383 * <p> If this {@code Class} object represents a class or interface that
2384 * has multiple declared methods with the same name and parameter types,
2385 * but different return types, then the returned array has a {@code Method}
2386 * object for each such method.
2387 *
2388 * <p> If this {@code Class} object represents a class or interface that
2389 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2390 * then the returned array does <em>not</em> have a corresponding {@code
2391 * Method} object.
2392 *
2393 * <p> If this {@code Class} object represents a class or interface with no
2394 * declared methods, then the returned array has length 0.
2395 *
2396 * <p> If this {@code Class} object represents an array type, a primitive
2397 * type, or void, then the returned array has length 0.
2398 *
2399 * <p> The elements in the returned array are not sorted and are not in any
2400 * particular order.
2401 *
2402 * @return the array of {@code Method} objects representing all the
2403 * declared methods of this class
2404 *
2405 * @jls 8.2 Class Members
2406 * @jls 8.4 Method Declarations
2407 * @see <a
2408 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2409 * programming language and JVM modeling in core reflection</a>
2410 * @since 1.1
2411 */
2412 public Method[] getDeclaredMethods() {
2413 return copyMethods(privateGetDeclaredMethods(false));
2414 }
2415
2416 /**
2417 * Returns an array of {@code Constructor} objects reflecting all the
2418 * constructors implicitly or explicitly declared by the class represented by this
2419 * {@code Class} object. These are public, protected, default
2420 * (package) access, and private constructors. The elements in the array
2421 * returned are not sorted and are not in any particular order. If the
2422 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2423 * If a record class has a canonical constructor (JLS {@jls
2424 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2425 *
2426 * This method returns an array of length 0 if this {@code Class}
2427 * object represents an interface, a primitive type, an array class, or
2428 * void.
2429 *
2430 * @return the array of {@code Constructor} objects representing all the
2431 * declared constructors of this class
2432 *
2433 * @since 1.1
2434 * @see #getConstructors()
2435 * @jls 8.8 Constructor Declarations
2436 */
2437 public Constructor<?>[] getDeclaredConstructors() {
2438 return copyConstructors(privateGetDeclaredConstructors(false));
2439 }
2440
2441
2442 /**
2443 * Returns a {@code Field} object that reflects the specified declared
2444 * field of the class or interface represented by this {@code Class}
2445 * object. The {@code name} parameter is a {@code String} that specifies
2446 * the simple name of the desired field.
2447 *
2448 * <p> If this {@code Class} object represents an array type, then this
2449 * method does not find the {@code length} field of the array type.
2450 *
2451 * @param name the name of the field
2452 * @return the {@code Field} object for the specified field in this
2453 * class
2454 * @throws NoSuchFieldException if a field with the specified name is
2455 * not found.
2456 * @throws NullPointerException if {@code name} is {@code null}
2457 *
2458 * @since 1.1
2459 * @jls 8.2 Class Members
2460 * @jls 8.3 Field Declarations
2461 */
2462 public Field getDeclaredField(String name) throws NoSuchFieldException {
2463 Objects.requireNonNull(name);
2464 Field field = searchFields(privateGetDeclaredFields(false), name);
2465 if (field == null) {
2466 throw new NoSuchFieldException(name);
2467 }
2468 return getReflectionFactory().copyField(field);
2469 }
2470
2471
2472 /**
2473 * Returns a {@code Method} object that reflects the specified
2474 * declared method of the class or interface represented by this
2475 * {@code Class} object. The {@code name} parameter is a
2476 * {@code String} that specifies the simple name of the desired
2477 * method, and the {@code parameterTypes} parameter is an array of
2478 * {@code Class} objects that identify the method's formal parameter
2479 * types, in declared order. If more than one method with the same
2480 * parameter types is declared in a class, and one of these methods has a
2481 * return type that is more specific than any of the others, that method is
2482 * returned; otherwise one of the methods is chosen arbitrarily. If the
2483 * name is {@value ConstantDescs#INIT_NAME} or {@value
2484 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2485 * is raised.
2486 *
2487 * <p> If this {@code Class} object represents an array type, then this
2488 * method does not find the {@code clone()} method.
2489 *
2490 * @param name the name of the method
2491 * @param parameterTypes the parameter array
2492 * @return the {@code Method} object for the method of this class
2493 * matching the specified name and parameters
2494 * @throws NoSuchMethodException if a matching method is not found.
2495 * @throws NullPointerException if {@code name} is {@code null}
2496 *
2497 * @jls 8.2 Class Members
2498 * @jls 8.4 Method Declarations
2499 * @since 1.1
2500 */
2501 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2502 throws NoSuchMethodException {
2503 Objects.requireNonNull(name);
2504 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2505 if (method == null) {
2506 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2507 }
2508 return getReflectionFactory().copyMethod(method);
2509 }
2510
2511 /**
2512 * Returns the list of {@code Method} objects for the declared public
2513 * methods of this class or interface that have the specified method name
2514 * and parameter types.
2515 *
2516 * @param name the name of the method
2517 * @param parameterTypes the parameter array
2518 * @return the list of {@code Method} objects for the public methods of
2519 * this class matching the specified name and parameters
2520 */
2521 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2522 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2523 ReflectionFactory factory = getReflectionFactory();
2524 List<Method> result = new ArrayList<>();
2525 for (Method method : methods) {
2526 if (method.getName().equals(name)
2527 && Arrays.equals(
2528 factory.getExecutableSharedParameterTypes(method),
2529 parameterTypes)) {
2530 result.add(factory.copyMethod(method));
2531 }
2532 }
2533 return result;
2534 }
2535
2536 /**
2537 * Returns the most specific {@code Method} object of this class, super class or
2538 * interface that have the specified method name and parameter types.
2539 *
2540 * @param publicOnly true if only public methods are examined, otherwise all methods
2541 * @param name the name of the method
2542 * @param parameterTypes the parameter array
2543 * @return the {@code Method} object for the method found from this class matching
2544 * the specified name and parameters, or null if not found
2545 */
2546 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2547 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2548 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2549 }
2550
2551 /**
2552 * Returns a {@code Constructor} object that reflects the specified
2553 * constructor of the class represented by this
2554 * {@code Class} object. The {@code parameterTypes} parameter is
2555 * an array of {@code Class} objects that identify the constructor's
2556 * formal parameter types, in declared order.
2557 *
2558 * If this {@code Class} object represents an inner class
2559 * declared in a non-static context, the formal parameter types
2560 * include the explicit enclosing instance as the first parameter.
2561 *
2562 * @param parameterTypes the parameter array
2563 * @return The {@code Constructor} object for the constructor with the
2564 * specified parameter list
2565 * @throws NoSuchMethodException if a matching constructor is not found,
2566 * including when this {@code Class} object represents
2567 * an interface, a primitive type, an array class, or void.
2568 *
2569 * @see #getConstructor(Class[])
2570 * @since 1.1
2571 */
2572 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2573 throws NoSuchMethodException {
2574 return getReflectionFactory().copyConstructor(
2575 getConstructor0(parameterTypes, Member.DECLARED));
2576 }
2577
2578 /**
2579 * Finds a resource with a given name.
2580 *
2581 * <p> If this class is in a named {@link Module Module} then this method
2582 * will attempt to find the resource in the module. This is done by
2583 * delegating to the module's class loader {@link
2584 * ClassLoader#findResource(String,String) findResource(String,String)}
2585 * method, invoking it with the module name and the absolute name of the
2586 * resource. Resources in named modules are subject to the rules for
2587 * encapsulation specified in the {@code Module} {@link
2588 * Module#getResourceAsStream getResourceAsStream} method and so this
2589 * method returns {@code null} when the resource is a
2590 * non-"{@code .class}" resource in a package that is not open to the
2591 * caller's module.
2592 *
2593 * <p> Otherwise, if this class is not in a named module then the rules for
2594 * searching resources associated with a given class are implemented by the
2595 * defining {@linkplain ClassLoader class loader} of the class. This method
2596 * delegates to this {@code Class} object's class loader.
2597 * If this {@code Class} object was loaded by the bootstrap class loader,
2598 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2599 *
2600 * <p> Before delegation, an absolute resource name is constructed from the
2601 * given resource name using this algorithm:
2602 *
2603 * <ul>
2604 *
2605 * <li> If the {@code name} begins with a {@code '/'}
2606 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2607 * portion of the {@code name} following the {@code '/'}.
2608 *
2609 * <li> Otherwise, the absolute name is of the following form:
2610 *
2611 * <blockquote>
2612 * {@code modified_package_name/name}
2613 * </blockquote>
2614 *
2615 * <p> Where the {@code modified_package_name} is the package name of this
2616 * object with {@code '/'} substituted for {@code '.'}
2617 * (<code>'\u002e'</code>).
2618 *
2619 * </ul>
2620 *
2621 * @param name name of the desired resource
2622 * @return A {@link java.io.InputStream} object; {@code null} if no
2623 * resource with this name is found, or the resource is in a package
2624 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2625 * least the caller module.
2626 * @throws NullPointerException If {@code name} is {@code null}
2627 *
2628 * @see Module#getResourceAsStream(String)
2629 * @since 1.1
2630 */
2631 @CallerSensitive
2632 public InputStream getResourceAsStream(String name) {
2633 name = resolveName(name);
2634
2635 Module thisModule = getModule();
2636 if (thisModule.isNamed()) {
2637 // check if resource can be located by caller
2638 if (Resources.canEncapsulate(name)
2639 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2640 return null;
2641 }
2642
2643 // resource not encapsulated or in package open to caller
2644 String mn = thisModule.getName();
2645 ClassLoader cl = classLoader;
2646 try {
2647
2648 // special-case built-in class loaders to avoid the
2649 // need for a URL connection
2650 if (cl == null) {
2651 return BootLoader.findResourceAsStream(mn, name);
2652 } else if (cl instanceof BuiltinClassLoader bcl) {
2653 return bcl.findResourceAsStream(mn, name);
2654 } else {
2655 URL url = cl.findResource(mn, name);
2656 return (url != null) ? url.openStream() : null;
2657 }
2658
2659 } catch (IOException | SecurityException e) {
2660 return null;
2661 }
2662 }
2663
2664 // unnamed module
2665 ClassLoader cl = classLoader;
2666 if (cl == null) {
2667 return ClassLoader.getSystemResourceAsStream(name);
2668 } else {
2669 return cl.getResourceAsStream(name);
2670 }
2671 }
2672
2673 /**
2674 * Finds a resource with a given name.
2675 *
2676 * <p> If this class is in a named {@link Module Module} then this method
2677 * will attempt to find the resource in the module. This is done by
2678 * delegating to the module's class loader {@link
2679 * ClassLoader#findResource(String,String) findResource(String,String)}
2680 * method, invoking it with the module name and the absolute name of the
2681 * resource. Resources in named modules are subject to the rules for
2682 * encapsulation specified in the {@code Module} {@link
2683 * Module#getResourceAsStream getResourceAsStream} method and so this
2684 * method returns {@code null} when the resource is a
2685 * non-"{@code .class}" resource in a package that is not open to the
2686 * caller's module.
2687 *
2688 * <p> Otherwise, if this class is not in a named module then the rules for
2689 * searching resources associated with a given class are implemented by the
2690 * defining {@linkplain ClassLoader class loader} of the class. This method
2691 * delegates to this {@code Class} object's class loader.
2692 * If this {@code Class} object was loaded by the bootstrap class loader,
2693 * the method delegates to {@link ClassLoader#getSystemResource}.
2694 *
2695 * <p> Before delegation, an absolute resource name is constructed from the
2696 * given resource name using this algorithm:
2697 *
2698 * <ul>
2699 *
2700 * <li> If the {@code name} begins with a {@code '/'}
2701 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2702 * portion of the {@code name} following the {@code '/'}.
2703 *
2704 * <li> Otherwise, the absolute name is of the following form:
2705 *
2706 * <blockquote>
2707 * {@code modified_package_name/name}
2708 * </blockquote>
2709 *
2710 * <p> Where the {@code modified_package_name} is the package name of this
2711 * object with {@code '/'} substituted for {@code '.'}
2712 * (<code>'\u002e'</code>).
2713 *
2714 * </ul>
2715 *
2716 * @param name name of the desired resource
2717 * @return A {@link java.net.URL} object; {@code null} if no resource with
2718 * this name is found, the resource cannot be located by a URL, or the
2719 * resource is in a package that is not
2720 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2721 * module.
2722 * @throws NullPointerException If {@code name} is {@code null}
2723 * @since 1.1
2724 */
2725 @CallerSensitive
2726 public URL getResource(String name) {
2727 name = resolveName(name);
2728
2729 Module thisModule = getModule();
2730 if (thisModule.isNamed()) {
2731 // check if resource can be located by caller
2732 if (Resources.canEncapsulate(name)
2733 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2734 return null;
2735 }
2736
2737 // resource not encapsulated or in package open to caller
2738 String mn = thisModule.getName();
2739 ClassLoader cl = classLoader;
2740 try {
2741 if (cl == null) {
2742 return BootLoader.findResource(mn, name);
2743 } else {
2744 return cl.findResource(mn, name);
2745 }
2746 } catch (IOException ioe) {
2747 return null;
2748 }
2749 }
2750
2751 // unnamed module
2752 ClassLoader cl = classLoader;
2753 if (cl == null) {
2754 return ClassLoader.getSystemResource(name);
2755 } else {
2756 return cl.getResource(name);
2757 }
2758 }
2759
2760 /**
2761 * Returns true if a resource with the given name can be located by the
2762 * given caller. All resources in a module can be located by code in
2763 * the module. For other callers, then the package needs to be open to
2764 * the caller.
2765 */
2766 private boolean isOpenToCaller(String name, Class<?> caller) {
2767 // assert getModule().isNamed();
2768 Module thisModule = getModule();
2769 Module callerModule = (caller != null) ? caller.getModule() : null;
2770 if (callerModule != thisModule) {
2771 String pn = Resources.toPackageName(name);
2772 if (thisModule.getDescriptor().packages().contains(pn)) {
2773 if (callerModule == null) {
2774 // no caller, return true if the package is open to all modules
2775 return thisModule.isOpen(pn);
2776 }
2777 if (!thisModule.isOpen(pn, callerModule)) {
2778 // package not open to caller
2779 return false;
2780 }
2781 }
2782 }
2783 return true;
2784 }
2785
2786 private transient final ProtectionDomain protectionDomain;
2787
2788 /** Holder for the protection domain returned when the internal domain is null */
2789 private static class Holder {
2790 private static final ProtectionDomain allPermDomain;
2791 static {
2792 Permissions perms = new Permissions();
2793 perms.add(new AllPermission());
2794 allPermDomain = new ProtectionDomain(null, perms);
2795 }
2796 }
2797
2798 /**
2799 * Returns the {@code ProtectionDomain} of this class.
2800 *
2801 * @return the ProtectionDomain of this class
2802 *
2803 * @see java.security.ProtectionDomain
2804 * @since 1.2
2805 */
2806 public ProtectionDomain getProtectionDomain() {
2807 if (protectionDomain == null) {
2808 return Holder.allPermDomain;
2809 } else {
2810 return protectionDomain;
2811 }
2812 }
2813
2814 /*
2815 * Returns the Class object for the named primitive type. Type parameter T
2816 * avoids redundant casts for trusted code.
2817 */
2818 static native <T> Class<T> getPrimitiveClass(String name);
2819
2820 /**
2821 * Add a package name prefix if the name is not absolute. Remove leading "/"
2822 * if name is absolute
2823 */
2824 private String resolveName(String name) {
2825 if (!name.startsWith("/")) {
2826 String baseName = getPackageName();
2827 if (!baseName.isEmpty()) {
2828 int len = baseName.length() + 1 + name.length();
2829 StringBuilder sb = new StringBuilder(len);
2830 name = sb.append(baseName.replace('.', '/'))
2831 .append('/')
2832 .append(name)
2833 .toString();
2834 }
2835 } else {
2836 name = name.substring(1);
2837 }
2838 return name;
2839 }
2840
2841 /**
2842 * Atomic operations support.
2843 */
2844 private static class Atomic {
2845 // initialize Unsafe machinery here, since we need to call Class.class instance method
2846 // and have to avoid calling it in the static initializer of the Class class...
2847 private static final Unsafe unsafe = Unsafe.getUnsafe();
2848 // offset of Class.reflectionData instance field
2849 private static final long reflectionDataOffset
2850 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2851 // offset of Class.annotationType instance field
2852 private static final long annotationTypeOffset
2853 = unsafe.objectFieldOffset(Class.class, "annotationType");
2854 // offset of Class.annotationData instance field
2855 private static final long annotationDataOffset
2856 = unsafe.objectFieldOffset(Class.class, "annotationData");
2857
2858 static <T> boolean casReflectionData(Class<?> clazz,
2859 SoftReference<ReflectionData<T>> oldData,
2860 SoftReference<ReflectionData<T>> newData) {
2861 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2862 }
2863
2864 static boolean casAnnotationType(Class<?> clazz,
2865 AnnotationType oldType,
2866 AnnotationType newType) {
2867 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2868 }
2869
2870 static boolean casAnnotationData(Class<?> clazz,
2871 AnnotationData oldData,
2872 AnnotationData newData) {
2873 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2874 }
2875 }
2876
2877 /**
2878 * Reflection support.
2879 */
2880
2881 // Reflection data caches various derived names and reflective members. Cached
2882 // values may be invalidated when JVM TI RedefineClasses() is called
2883 private static class ReflectionData<T> {
2884 volatile Field[] declaredFields;
2885 volatile Field[] publicFields;
2886 volatile Method[] declaredMethods;
2887 volatile Method[] publicMethods;
2888 volatile Constructor<T>[] declaredConstructors;
2889 volatile Constructor<T>[] publicConstructors;
2890 // Intermediate results for getFields and getMethods
2891 volatile Field[] declaredPublicFields;
2892 volatile Method[] declaredPublicMethods;
2893 volatile Class<?>[] interfaces;
2894
2895 // Cached names
2896 String simpleName;
2897 String canonicalName;
2898 static final String NULL_SENTINEL = new String();
2899
2900 // Value of classRedefinedCount when we created this ReflectionData instance
2901 final int redefinedCount;
2902
2903 ReflectionData(int redefinedCount) {
2904 this.redefinedCount = redefinedCount;
2905 }
2906 }
2907
2908 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2909
2910 // Incremented by the VM on each call to JVM TI RedefineClasses()
2911 // that redefines this class or a superclass.
2912 private transient volatile int classRedefinedCount;
2913
2914 // Lazily create and cache ReflectionData
2915 private ReflectionData<T> reflectionData() {
2916 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2917 int classRedefinedCount = this.classRedefinedCount;
2918 ReflectionData<T> rd;
2919 if (reflectionData != null &&
2920 (rd = reflectionData.get()) != null &&
2921 rd.redefinedCount == classRedefinedCount) {
2922 return rd;
2923 }
2924 // else no SoftReference or cleared SoftReference or stale ReflectionData
2925 // -> create and replace new instance
2926 return newReflectionData(reflectionData, classRedefinedCount);
2927 }
2928
2929 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2930 int classRedefinedCount) {
2931 while (true) {
2932 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2933 // try to CAS it...
2934 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
2935 return rd;
2936 }
2937 // else retry
2938 oldReflectionData = this.reflectionData;
2939 classRedefinedCount = this.classRedefinedCount;
2940 if (oldReflectionData != null &&
2941 (rd = oldReflectionData.get()) != null &&
2942 rd.redefinedCount == classRedefinedCount) {
2943 return rd;
2944 }
2945 }
2946 }
2947
2948 // Generic signature handling
2949 private native String getGenericSignature0();
2950
2951 // Generic info repository; lazily initialized
2952 private transient volatile ClassRepository genericInfo;
2953
2954 // accessor for factory
2955 private GenericsFactory getFactory() {
2956 // create scope and factory
2957 return CoreReflectionFactory.make(this, ClassScope.make(this));
2958 }
2959
2960 // accessor for generic info repository;
2961 // generic info is lazily initialized
2962 private ClassRepository getGenericInfo() {
2963 ClassRepository genericInfo = this.genericInfo;
2964 if (genericInfo == null) {
2965 String signature = getGenericSignature0();
2966 if (signature == null) {
2967 genericInfo = ClassRepository.NONE;
2968 } else {
2969 genericInfo = ClassRepository.make(signature, getFactory());
2970 }
2971 this.genericInfo = genericInfo;
2972 }
2973 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2974 }
2975
2976 // Annotations handling
2977 native byte[] getRawAnnotations();
2978 // Since 1.8
2979 native byte[] getRawTypeAnnotations();
2980 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2981 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2982 }
2983
2984 native ConstantPool getConstantPool();
2985
2986 //
2987 //
2988 // java.lang.reflect.Field handling
2989 //
2990 //
2991
2992 // Returns an array of "root" fields. These Field objects must NOT
2993 // be propagated to the outside world, but must instead be copied
2994 // via ReflectionFactory.copyField.
2995 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2996 Field[] res;
2997 ReflectionData<T> rd = reflectionData();
2998 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2999 if (res != null) return res;
3000 // No cached value available; request value from VM
3001 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
3002 if (publicOnly) {
3003 rd.declaredPublicFields = res;
3004 } else {
3005 rd.declaredFields = res;
3006 }
3007 return res;
3008 }
3009
3010 // Returns an array of "root" fields. These Field objects must NOT
3011 // be propagated to the outside world, but must instead be copied
3012 // via ReflectionFactory.copyField.
3013 private Field[] privateGetPublicFields() {
3014 Field[] res;
3015 ReflectionData<T> rd = reflectionData();
3016 res = rd.publicFields;
3017 if (res != null) return res;
3018
3019 // Use a linked hash set to ensure order is preserved and
3020 // fields from common super interfaces are not duplicated
3021 LinkedHashSet<Field> fields = new LinkedHashSet<>();
3022
3023 // Local fields
3024 addAll(fields, privateGetDeclaredFields(true));
3025
3026 // Direct superinterfaces, recursively
3027 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
3028 addAll(fields, si.privateGetPublicFields());
3029 }
3030
3031 // Direct superclass, recursively
3032 Class<?> sc = getSuperclass();
3033 if (sc != null) {
3034 addAll(fields, sc.privateGetPublicFields());
3035 }
3036
3037 res = fields.toArray(new Field[0]);
3038 rd.publicFields = res;
3039 return res;
3040 }
3041
3042 private static void addAll(Collection<Field> c, Field[] o) {
3043 for (Field f : o) {
3044 c.add(f);
3045 }
3046 }
3047
3048
3049 //
3050 //
3051 // java.lang.reflect.Constructor handling
3052 //
3053 //
3054
3055 // Returns an array of "root" constructors. These Constructor
3056 // objects must NOT be propagated to the outside world, but must
3057 // instead be copied via ReflectionFactory.copyConstructor.
3058 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3059 Constructor<T>[] res;
3060 ReflectionData<T> rd = reflectionData();
3061 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3062 if (res != null) return res;
3063 // No cached value available; request value from VM
3064 if (isInterface()) {
3065 @SuppressWarnings("unchecked")
3066 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3067 res = temporaryRes;
3068 } else {
3069 res = getDeclaredConstructors0(publicOnly);
3070 }
3071 if (publicOnly) {
3072 rd.publicConstructors = res;
3073 } else {
3074 rd.declaredConstructors = res;
3075 }
3076 return res;
3077 }
3078
3079 //
3080 //
3081 // java.lang.reflect.Method handling
3082 //
3083 //
3084
3085 // Returns an array of "root" methods. These Method objects must NOT
3086 // be propagated to the outside world, but must instead be copied
3087 // via ReflectionFactory.copyMethod.
3088 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3089 Method[] res;
3090 ReflectionData<T> rd = reflectionData();
3091 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3092 if (res != null) return res;
3093 // No cached value available; request value from VM
3094 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3095 if (publicOnly) {
3096 rd.declaredPublicMethods = res;
3097 } else {
3098 rd.declaredMethods = res;
3099 }
3100 return res;
3101 }
3102
3103 // Returns an array of "root" methods. These Method objects must NOT
3104 // be propagated to the outside world, but must instead be copied
3105 // via ReflectionFactory.copyMethod.
3106 private Method[] privateGetPublicMethods() {
3107 Method[] res;
3108 ReflectionData<T> rd = reflectionData();
3109 res = rd.publicMethods;
3110 if (res != null) return res;
3111
3112 // No cached value available; compute value recursively.
3113 // Start by fetching public declared methods...
3114 PublicMethods pms = new PublicMethods();
3115 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3116 pms.merge(m);
3117 }
3118 // ...then recur over superclass methods...
3119 Class<?> sc = getSuperclass();
3120 if (sc != null) {
3121 for (Method m : sc.privateGetPublicMethods()) {
3122 pms.merge(m);
3123 }
3124 }
3125 // ...and finally over direct superinterfaces.
3126 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3127 for (Method m : intf.privateGetPublicMethods()) {
3128 // static interface methods are not inherited
3129 if (!Modifier.isStatic(m.getModifiers())) {
3130 pms.merge(m);
3131 }
3132 }
3133 }
3134
3135 res = pms.toArray();
3136 rd.publicMethods = res;
3137 return res;
3138 }
3139
3140
3141 //
3142 // Helpers for fetchers of one field, method, or constructor
3143 //
3144
3145 // This method does not copy the returned Field object!
3146 private static Field searchFields(Field[] fields, String name) {
3147 for (Field field : fields) {
3148 if (field.getName().equals(name)) {
3149 return field;
3150 }
3151 }
3152 return null;
3153 }
3154
3155 // Returns a "root" Field object. This Field object must NOT
3156 // be propagated to the outside world, but must instead be copied
3157 // via ReflectionFactory.copyField.
3158 private Field getField0(String name) {
3159 // Note: the intent is that the search algorithm this routine
3160 // uses be equivalent to the ordering imposed by
3161 // privateGetPublicFields(). It fetches only the declared
3162 // public fields for each class, however, to reduce the number
3163 // of Field objects which have to be created for the common
3164 // case where the field being requested is declared in the
3165 // class which is being queried.
3166 Field res;
3167 // Search declared public fields
3168 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3169 return res;
3170 }
3171 // Direct superinterfaces, recursively
3172 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3173 for (Class<?> c : interfaces) {
3174 if ((res = c.getField0(name)) != null) {
3175 return res;
3176 }
3177 }
3178 // Direct superclass, recursively
3179 if (!isInterface()) {
3180 Class<?> c = getSuperclass();
3181 if (c != null) {
3182 if ((res = c.getField0(name)) != null) {
3183 return res;
3184 }
3185 }
3186 }
3187 return null;
3188 }
3189
3190 // This method does not copy the returned Method object!
3191 private static Method searchMethods(Method[] methods,
3192 String name,
3193 Class<?>[] parameterTypes)
3194 {
3195 ReflectionFactory fact = getReflectionFactory();
3196 Method res = null;
3197 for (Method m : methods) {
3198 if (m.getName().equals(name)
3199 && arrayContentsEq(parameterTypes,
3200 fact.getExecutableSharedParameterTypes(m))
3201 && (res == null
3202 || (res.getReturnType() != m.getReturnType()
3203 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3204 res = m;
3205 }
3206 return res;
3207 }
3208
3209 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3210
3211 // Returns a "root" Method object. This Method object must NOT
3212 // be propagated to the outside world, but must instead be copied
3213 // via ReflectionFactory.copyMethod.
3214 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3215 PublicMethods.MethodList res = getMethodsRecursive(
3216 name,
3217 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3218 /* includeStatic */ true, /* publicOnly */ true);
3219 return res == null ? null : res.getMostSpecific();
3220 }
3221
3222 // Returns a list of "root" Method objects. These Method objects must NOT
3223 // be propagated to the outside world, but must instead be copied
3224 // via ReflectionFactory.copyMethod.
3225 private PublicMethods.MethodList getMethodsRecursive(String name,
3226 Class<?>[] parameterTypes,
3227 boolean includeStatic,
3228 boolean publicOnly) {
3229 // 1st check declared methods
3230 Method[] methods = privateGetDeclaredMethods(publicOnly);
3231 PublicMethods.MethodList res = PublicMethods.MethodList
3232 .filter(methods, name, parameterTypes, includeStatic);
3233 // if there is at least one match among declared methods, we need not
3234 // search any further as such match surely overrides matching methods
3235 // declared in superclass(es) or interface(s).
3236 if (res != null) {
3237 return res;
3238 }
3239
3240 // if there was no match among declared methods,
3241 // we must consult the superclass (if any) recursively...
3242 Class<?> sc = getSuperclass();
3243 if (sc != null) {
3244 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3245 }
3246
3247 // ...and coalesce the superclass methods with methods obtained
3248 // from directly implemented interfaces excluding static methods...
3249 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3250 res = PublicMethods.MethodList.merge(
3251 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3252 }
3253
3254 return res;
3255 }
3256
3257 // Returns a "root" Constructor object. This Constructor object must NOT
3258 // be propagated to the outside world, but must instead be copied
3259 // via ReflectionFactory.copyConstructor.
3260 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3261 int which) throws NoSuchMethodException
3262 {
3263 ReflectionFactory fact = getReflectionFactory();
3264 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3265 for (Constructor<T> constructor : constructors) {
3266 if (arrayContentsEq(parameterTypes,
3267 fact.getExecutableSharedParameterTypes(constructor))) {
3268 return constructor;
3269 }
3270 }
3271 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3272 }
3273
3274 //
3275 // Other helpers and base implementation
3276 //
3277
3278 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3279 if (a1 == null) {
3280 return a2 == null || a2.length == 0;
3281 }
3282
3283 if (a2 == null) {
3284 return a1.length == 0;
3285 }
3286
3287 if (a1.length != a2.length) {
3288 return false;
3289 }
3290
3291 for (int i = 0; i < a1.length; i++) {
3292 if (a1[i] != a2[i]) {
3293 return false;
3294 }
3295 }
3296
3297 return true;
3298 }
3299
3300 private static Field[] copyFields(Field[] arg) {
3301 Field[] out = new Field[arg.length];
3302 ReflectionFactory fact = getReflectionFactory();
3303 for (int i = 0; i < arg.length; i++) {
3304 out[i] = fact.copyField(arg[i]);
3305 }
3306 return out;
3307 }
3308
3309 private static Method[] copyMethods(Method[] arg) {
3310 Method[] out = new Method[arg.length];
3311 ReflectionFactory fact = getReflectionFactory();
3312 for (int i = 0; i < arg.length; i++) {
3313 out[i] = fact.copyMethod(arg[i]);
3314 }
3315 return out;
3316 }
3317
3318 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3319 Constructor<U>[] out = arg.clone();
3320 ReflectionFactory fact = getReflectionFactory();
3321 for (int i = 0; i < out.length; i++) {
3322 out[i] = fact.copyConstructor(out[i]);
3323 }
3324 return out;
3325 }
3326
3327 private native Field[] getDeclaredFields0(boolean publicOnly);
3328 private native Method[] getDeclaredMethods0(boolean publicOnly);
3329 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3330 private native Class<?>[] getDeclaredClasses0();
3331
3332 /*
3333 * Returns an array containing the components of the Record attribute,
3334 * or null if the attribute is not present.
3335 *
3336 * Note that this method returns non-null array on a class with
3337 * the Record attribute even if this class is not a record.
3338 */
3339 private native RecordComponent[] getRecordComponents0();
3340 private native boolean isRecord0();
3341
3342 /**
3343 * Helper method to get the method name from arguments.
3344 */
3345 private String methodToString(String name, Class<?>[] argTypes) {
3346 return getName() + '.' + name +
3347 ((argTypes == null || argTypes.length == 0) ?
3348 "()" :
3349 Arrays.stream(argTypes)
3350 .map(c -> c == null ? "null" : c.getName())
3351 .collect(Collectors.joining(",", "(", ")")));
3352 }
3353
3354 /** use serialVersionUID from JDK 1.1 for interoperability */
3355 @java.io.Serial
3356 private static final long serialVersionUID = 3206093459760846163L;
3357
3358
3359 /**
3360 * Class Class is special cased within the Serialization Stream Protocol.
3361 *
3362 * A Class instance is written initially into an ObjectOutputStream in the
3363 * following format:
3364 * <pre>
3365 * {@code TC_CLASS} ClassDescriptor
3366 * A ClassDescriptor is a special cased serialization of
3367 * a {@code java.io.ObjectStreamClass} instance.
3368 * </pre>
3369 * A new handle is generated for the initial time the class descriptor
3370 * is written into the stream. Future references to the class descriptor
3371 * are written as references to the initial class descriptor instance.
3372 *
3373 * @see java.io.ObjectStreamClass
3374 */
3375 @java.io.Serial
3376 private static final ObjectStreamField[] serialPersistentFields =
3377 new ObjectStreamField[0];
3378
3379
3380 /**
3381 * Returns the assertion status that would be assigned to this
3382 * class if it were to be initialized at the time this method is invoked.
3383 * If this class has had its assertion status set, the most recent
3384 * setting will be returned; otherwise, if any package default assertion
3385 * status pertains to this class, the most recent setting for the most
3386 * specific pertinent package default assertion status is returned;
3387 * otherwise, if this class is not a system class (i.e., it has a
3388 * class loader) its class loader's default assertion status is returned;
3389 * otherwise, the system class default assertion status is returned.
3390 *
3391 * @apiNote
3392 * Few programmers will have any need for this method; it is provided
3393 * for the benefit of the JDK itself. (It allows a class to determine at
3394 * the time that it is initialized whether assertions should be enabled.)
3395 * Note that this method is not guaranteed to return the actual
3396 * assertion status that was (or will be) associated with the specified
3397 * class when it was (or will be) initialized.
3398 *
3399 * @return the desired assertion status of the specified class.
3400 * @see java.lang.ClassLoader#setClassAssertionStatus
3401 * @see java.lang.ClassLoader#setPackageAssertionStatus
3402 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3403 * @since 1.4
3404 */
3405 public boolean desiredAssertionStatus() {
3406 ClassLoader loader = classLoader;
3407 // If the loader is null this is a system class, so ask the VM
3408 if (loader == null)
3409 return desiredAssertionStatus0(this);
3410
3411 // If the classloader has been initialized with the assertion
3412 // directives, ask it. Otherwise, ask the VM.
3413 synchronized(loader.assertionLock) {
3414 if (loader.classAssertionStatus != null) {
3415 return loader.desiredAssertionStatus(getName());
3416 }
3417 }
3418 return desiredAssertionStatus0(this);
3419 }
3420
3421 // Retrieves the desired assertion status of this class from the VM
3422 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3423
3424 /**
3425 * Returns true if and only if this class was declared as an enum in the
3426 * source code.
3427 *
3428 * Note that {@link java.lang.Enum} is not itself an enum class.
3429 *
3430 * Also note that if an enum constant is declared with a class body,
3431 * the class of that enum constant object is an anonymous class
3432 * and <em>not</em> the class of the declaring enum class. The
3433 * {@link Enum#getDeclaringClass} method of an enum constant can
3434 * be used to get the class of the enum class declaring the
3435 * constant.
3436 *
3437 * @return true if and only if this class was declared as an enum in the
3438 * source code
3439 * @since 1.5
3440 * @jls 8.9.1 Enum Constants
3441 */
3442 public boolean isEnum() {
3443 // An enum must both directly extend java.lang.Enum and have
3444 // the ENUM bit set; classes for specialized enum constants
3445 // don't do the former.
3446 return (this.getModifiers() & ENUM) != 0 &&
3447 this.getSuperclass() == java.lang.Enum.class;
3448 }
3449
3450 /**
3451 * Returns {@code true} if and only if this class is a record class.
3452 *
3453 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3454 * class is {@code java.lang.Record}. A record class is {@linkplain
3455 * Modifier#FINAL final}. A record class has (possibly zero) record
3456 * components; {@link #getRecordComponents()} returns a non-null but
3457 * possibly empty value for a record.
3458 *
3459 * <p> Note that class {@link Record} is not a record class and thus
3460 * invoking this method on class {@code Record} returns {@code false}.
3461 *
3462 * @return true if and only if this class is a record class, otherwise false
3463 * @jls 8.10 Record Classes
3464 * @since 16
3465 */
3466 public boolean isRecord() {
3467 // this superclass and final modifier check is not strictly necessary
3468 // they are intrinsified and serve as a fast-path check
3469 return getSuperclass() == java.lang.Record.class &&
3470 (this.getModifiers() & Modifier.FINAL) != 0 &&
3471 isRecord0();
3472 }
3473
3474 // Fetches the factory for reflective objects
3475 private static ReflectionFactory getReflectionFactory() {
3476 var factory = reflectionFactory;
3477 if (factory != null) {
3478 return factory;
3479 }
3480 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3481 }
3482 private static ReflectionFactory reflectionFactory;
3483
3484 /**
3485 * When CDS is enabled, the Class class may be aot-initialized. However,
3486 * we can't archive reflectionFactory, so we reset it to null, so it
3487 * will be allocated again at runtime.
3488 */
3489 private static void resetArchivedStates() {
3490 reflectionFactory = null;
3491 }
3492
3493 /**
3494 * Returns the elements of this enum class or null if this
3495 * Class object does not represent an enum class.
3496 *
3497 * @return an array containing the values comprising the enum class
3498 * represented by this {@code Class} object in the order they're
3499 * declared, or null if this {@code Class} object does not
3500 * represent an enum class
3501 * @since 1.5
3502 * @jls 8.9.1 Enum Constants
3503 */
3504 public T[] getEnumConstants() {
3505 T[] values = getEnumConstantsShared();
3506 return (values != null) ? values.clone() : null;
3507 }
3508
3509 /**
3510 * Returns the elements of this enum class or null if this
3511 * Class object does not represent an enum class;
3512 * identical to getEnumConstants except that the result is
3513 * uncloned, cached, and shared by all callers.
3514 */
3515 T[] getEnumConstantsShared() {
3516 T[] constants = enumConstants;
3517 if (constants == null) {
3518 if (!isEnum()) return null;
3519 try {
3520 final Method values = getMethod("values");
3521 values.setAccessible(true);
3522 @SuppressWarnings("unchecked")
3523 T[] temporaryConstants = (T[])values.invoke(null);
3524 enumConstants = constants = temporaryConstants;
3525 }
3526 // These can happen when users concoct enum-like classes
3527 // that don't comply with the enum spec.
3528 catch (InvocationTargetException | NoSuchMethodException |
3529 IllegalAccessException | NullPointerException |
3530 ClassCastException ex) { return null; }
3531 }
3532 return constants;
3533 }
3534 private transient volatile T[] enumConstants;
3535
3536 /**
3537 * Returns a map from simple name to enum constant. This package-private
3538 * method is used internally by Enum to implement
3539 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3540 * efficiently. Note that the map is returned by this method is
3541 * created lazily on first use. Typically it won't ever get created.
3542 */
3543 Map<String, T> enumConstantDirectory() {
3544 Map<String, T> directory = enumConstantDirectory;
3545 if (directory == null) {
3546 T[] universe = getEnumConstantsShared();
3547 if (universe == null)
3548 throw new IllegalArgumentException(
3549 getName() + " is not an enum class");
3550 directory = HashMap.newHashMap(universe.length);
3551 for (T constant : universe) {
3552 directory.put(((Enum<?>)constant).name(), constant);
3553 }
3554 enumConstantDirectory = directory;
3555 }
3556 return directory;
3557 }
3558 private transient volatile Map<String, T> enumConstantDirectory;
3559
3560 /**
3561 * Casts an object to the class or interface represented
3562 * by this {@code Class} object.
3563 *
3564 * @param obj the object to be cast
3565 * @return the object after casting, or null if obj is null
3566 *
3567 * @throws ClassCastException if the object is not
3568 * null and is not assignable to the type T.
3569 *
3570 * @since 1.5
3571 */
3572 @SuppressWarnings("unchecked")
3573 @IntrinsicCandidate
3574 public T cast(Object obj) {
3575 if (obj != null && !isInstance(obj))
3576 throw new ClassCastException(cannotCastMsg(obj));
3577 return (T) obj;
3578 }
3579
3580 private String cannotCastMsg(Object obj) {
3581 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3582 }
3583
3584 /**
3585 * Casts this {@code Class} object to represent a subclass of the class
3586 * represented by the specified class object. Checks that the cast
3587 * is valid, and throws a {@code ClassCastException} if it is not. If
3588 * this method succeeds, it always returns a reference to this {@code Class} object.
3589 *
3590 * <p>This method is useful when a client needs to "narrow" the type of
3591 * a {@code Class} object to pass it to an API that restricts the
3592 * {@code Class} objects that it is willing to accept. A cast would
3593 * generate a compile-time warning, as the correctness of the cast
3594 * could not be checked at runtime (because generic types are implemented
3595 * by erasure).
3596 *
3597 * @param <U> the type to cast this {@code Class} object to
3598 * @param clazz the class of the type to cast this {@code Class} object to
3599 * @return this {@code Class} object, cast to represent a subclass of
3600 * the specified class object.
3601 * @throws ClassCastException if this {@code Class} object does not
3602 * represent a subclass of the specified class (here "subclass" includes
3603 * the class itself).
3604 * @since 1.5
3605 */
3606 @SuppressWarnings("unchecked")
3607 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3608 if (clazz.isAssignableFrom(this))
3609 return (Class<? extends U>) this;
3610 else
3611 throw new ClassCastException(this.toString());
3612 }
3613
3614 /**
3615 * {@inheritDoc}
3616 * <p>Note that any annotation returned by this method is a
3617 * declaration annotation.
3618 *
3619 * @throws NullPointerException {@inheritDoc}
3620 * @since 1.5
3621 */
3622 @Override
3623 @SuppressWarnings("unchecked")
3624 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3625 Objects.requireNonNull(annotationClass);
3626
3627 return (A) annotationData().annotations.get(annotationClass);
3628 }
3629
3630 /**
3631 * {@inheritDoc}
3632 * @throws NullPointerException {@inheritDoc}
3633 * @since 1.5
3634 */
3635 @Override
3636 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3637 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3638 }
3639
3640 /**
3641 * {@inheritDoc}
3642 * <p>Note that any annotations returned by this method are
3643 * declaration annotations.
3644 *
3645 * @throws NullPointerException {@inheritDoc}
3646 * @since 1.8
3647 */
3648 @Override
3649 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3650 Objects.requireNonNull(annotationClass);
3651
3652 AnnotationData annotationData = annotationData();
3653 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3654 this,
3655 annotationClass);
3656 }
3657
3658 /**
3659 * {@inheritDoc}
3660 * <p>Note that any annotations returned by this method are
3661 * declaration annotations.
3662 *
3663 * @since 1.5
3664 */
3665 @Override
3666 public Annotation[] getAnnotations() {
3667 return AnnotationParser.toArray(annotationData().annotations);
3668 }
3669
3670 /**
3671 * {@inheritDoc}
3672 * <p>Note that any annotation returned by this method is a
3673 * declaration annotation.
3674 *
3675 * @throws NullPointerException {@inheritDoc}
3676 * @since 1.8
3677 */
3678 @Override
3679 @SuppressWarnings("unchecked")
3680 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3681 Objects.requireNonNull(annotationClass);
3682
3683 return (A) annotationData().declaredAnnotations.get(annotationClass);
3684 }
3685
3686 /**
3687 * {@inheritDoc}
3688 * <p>Note that any annotations returned by this method are
3689 * declaration annotations.
3690 *
3691 * @throws NullPointerException {@inheritDoc}
3692 * @since 1.8
3693 */
3694 @Override
3695 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3696 Objects.requireNonNull(annotationClass);
3697
3698 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3699 annotationClass);
3700 }
3701
3702 /**
3703 * {@inheritDoc}
3704 * <p>Note that any annotations returned by this method are
3705 * declaration annotations.
3706 *
3707 * @since 1.5
3708 */
3709 @Override
3710 public Annotation[] getDeclaredAnnotations() {
3711 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3712 }
3713
3714 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3715 private static class AnnotationData {
3716 final Map<Class<? extends Annotation>, Annotation> annotations;
3717 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3718
3719 // Value of classRedefinedCount when we created this AnnotationData instance
3720 final int redefinedCount;
3721
3722 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3723 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3724 int redefinedCount) {
3725 this.annotations = annotations;
3726 this.declaredAnnotations = declaredAnnotations;
3727 this.redefinedCount = redefinedCount;
3728 }
3729 }
3730
3731 // Annotations cache
3732 @SuppressWarnings("UnusedDeclaration")
3733 private transient volatile AnnotationData annotationData;
3734
3735 private AnnotationData annotationData() {
3736 while (true) { // retry loop
3737 AnnotationData annotationData = this.annotationData;
3738 int classRedefinedCount = this.classRedefinedCount;
3739 if (annotationData != null &&
3740 annotationData.redefinedCount == classRedefinedCount) {
3741 return annotationData;
3742 }
3743 // null or stale annotationData -> optimistically create new instance
3744 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3745 // try to install it
3746 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3747 // successfully installed new AnnotationData
3748 return newAnnotationData;
3749 }
3750 }
3751 }
3752
3753 private AnnotationData createAnnotationData(int classRedefinedCount) {
3754 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3755 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3756 Class<?> superClass = getSuperclass();
3757 Map<Class<? extends Annotation>, Annotation> annotations = null;
3758 if (superClass != null) {
3759 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3760 superClass.annotationData().annotations;
3761 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3762 Class<? extends Annotation> annotationClass = e.getKey();
3763 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3764 if (annotations == null) { // lazy construction
3765 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3766 declaredAnnotations.size(),
3767 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3768 )
3769 );
3770 }
3771 annotations.put(annotationClass, e.getValue());
3772 }
3773 }
3774 }
3775 if (annotations == null) {
3776 // no inherited annotations -> share the Map with declaredAnnotations
3777 annotations = declaredAnnotations;
3778 } else {
3779 // at least one inherited annotation -> declared may override inherited
3780 annotations.putAll(declaredAnnotations);
3781 }
3782 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3783 }
3784
3785 // Annotation interfaces cache their internal (AnnotationType) form
3786
3787 @SuppressWarnings("UnusedDeclaration")
3788 private transient volatile AnnotationType annotationType;
3789
3790 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3791 return Atomic.casAnnotationType(this, oldType, newType);
3792 }
3793
3794 AnnotationType getAnnotationType() {
3795 return annotationType;
3796 }
3797
3798 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3799 return annotationData().declaredAnnotations;
3800 }
3801
3802 /* Backing store of user-defined values pertaining to this class.
3803 * Maintained by the ClassValue class.
3804 */
3805 transient ClassValue.ClassValueMap classValueMap;
3806
3807 /**
3808 * Returns an {@code AnnotatedType} object that represents the use of a
3809 * type to specify the superclass of the entity represented by this {@code
3810 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3811 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3812 * Foo.)
3813 *
3814 * <p> If this {@code Class} object represents a class whose declaration
3815 * does not explicitly indicate an annotated superclass, then the return
3816 * value is an {@code AnnotatedType} object representing an element with no
3817 * annotations.
3818 *
3819 * <p> If this {@code Class} represents either the {@code Object} class, an
3820 * interface type, an array type, a primitive type, or void, the return
3821 * value is {@code null}.
3822 *
3823 * @return an object representing the superclass
3824 * @since 1.8
3825 */
3826 public AnnotatedType getAnnotatedSuperclass() {
3827 if (this == Object.class ||
3828 isInterface() ||
3829 isArray() ||
3830 isPrimitive() ||
3831 this == Void.TYPE) {
3832 return null;
3833 }
3834
3835 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3836 }
3837
3838 /**
3839 * Returns an array of {@code AnnotatedType} objects that represent the use
3840 * of types to specify superinterfaces of the entity represented by this
3841 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3842 * superinterface in '... implements Foo' is distinct from the
3843 * <em>declaration</em> of interface Foo.)
3844 *
3845 * <p> If this {@code Class} object represents a class, the return value is
3846 * an array containing objects representing the uses of interface types to
3847 * specify interfaces implemented by the class. The order of the objects in
3848 * the array corresponds to the order of the interface types used in the
3849 * 'implements' clause of the declaration of this {@code Class} object.
3850 *
3851 * <p> If this {@code Class} object represents an interface, the return
3852 * value is an array containing objects representing the uses of interface
3853 * types to specify interfaces directly extended by the interface. The
3854 * order of the objects in the array corresponds to the order of the
3855 * interface types used in the 'extends' clause of the declaration of this
3856 * {@code Class} object.
3857 *
3858 * <p> If this {@code Class} object represents a class or interface whose
3859 * declaration does not explicitly indicate any annotated superinterfaces,
3860 * the return value is an array of length 0.
3861 *
3862 * <p> If this {@code Class} object represents either the {@code Object}
3863 * class, an array type, a primitive type, or void, the return value is an
3864 * array of length 0.
3865 *
3866 * @return an array representing the superinterfaces
3867 * @since 1.8
3868 */
3869 public AnnotatedType[] getAnnotatedInterfaces() {
3870 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3871 }
3872
3873 private native Class<?> getNestHost0();
3874
3875 /**
3876 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3877 * or interface represented by this {@code Class} object belongs.
3878 * Every class and interface belongs to exactly one nest.
3879 *
3880 * If the nest host of this class or interface has previously
3881 * been determined, then this method returns the nest host.
3882 * If the nest host of this class or interface has
3883 * not previously been determined, then this method determines the nest
3884 * host using the algorithm of JVMS 5.4.4, and returns it.
3885 *
3886 * Often, a class or interface belongs to a nest consisting only of itself,
3887 * in which case this method returns {@code this} to indicate that the class
3888 * or interface is the nest host.
3889 *
3890 * <p>If this {@code Class} object represents a primitive type, an array type,
3891 * or {@code void}, then this method returns {@code this},
3892 * indicating that the represented entity belongs to the nest consisting only of
3893 * itself, and is the nest host.
3894 *
3895 * @return the nest host of this class or interface
3896 *
3897 * @since 11
3898 * @jvms 4.7.28 The {@code NestHost} Attribute
3899 * @jvms 4.7.29 The {@code NestMembers} Attribute
3900 * @jvms 5.4.4 Access Control
3901 */
3902 public Class<?> getNestHost() {
3903 if (isPrimitive() || isArray()) {
3904 return this;
3905 }
3906 return getNestHost0();
3907 }
3908
3909 /**
3910 * Determines if the given {@code Class} is a nestmate of the
3911 * class or interface represented by this {@code Class} object.
3912 * Two classes or interfaces are nestmates
3913 * if they have the same {@linkplain #getNestHost() nest host}.
3914 *
3915 * @param c the class to check
3916 * @return {@code true} if this class and {@code c} are members of
3917 * the same nest; and {@code false} otherwise.
3918 *
3919 * @since 11
3920 */
3921 public boolean isNestmateOf(Class<?> c) {
3922 if (this == c) {
3923 return true;
3924 }
3925 if (isPrimitive() || isArray() ||
3926 c.isPrimitive() || c.isArray()) {
3927 return false;
3928 }
3929
3930 return getNestHost() == c.getNestHost();
3931 }
3932
3933 private native Class<?>[] getNestMembers0();
3934
3935 /**
3936 * Returns an array containing {@code Class} objects representing all the
3937 * classes and interfaces that are members of the nest to which the class
3938 * or interface represented by this {@code Class} object belongs.
3939 *
3940 * First, this method obtains the {@linkplain #getNestHost() nest host},
3941 * {@code H}, of the nest to which the class or interface represented by
3942 * this {@code Class} object belongs. The zeroth element of the returned
3943 * array is {@code H}.
3944 *
3945 * Then, for each class or interface {@code C} which is recorded by {@code H}
3946 * as being a member of its nest, this method attempts to obtain the {@code Class}
3947 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3948 * loader} of the current {@code Class} object), and then obtains the
3949 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3950 * The classes and interfaces which are recorded by {@code H} as being members
3951 * of its nest, and for which {@code H} can be determined as their nest host,
3952 * are indicated by subsequent elements of the returned array. The order of
3953 * such elements is unspecified. Duplicates are permitted.
3954 *
3955 * <p>If this {@code Class} object represents a primitive type, an array type,
3956 * or {@code void}, then this method returns a single-element array containing
3957 * {@code this}.
3958 *
3959 * @apiNote
3960 * The returned array includes only the nest members recorded in the {@code NestMembers}
3961 * attribute, and not any hidden classes that were added to the nest via
3962 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3963 * Lookup::defineHiddenClass}.
3964 *
3965 * @return an array of all classes and interfaces in the same nest as
3966 * this class or interface
3967 *
3968 * @since 11
3969 * @see #getNestHost()
3970 * @jvms 4.7.28 The {@code NestHost} Attribute
3971 * @jvms 4.7.29 The {@code NestMembers} Attribute
3972 */
3973 public Class<?>[] getNestMembers() {
3974 if (isPrimitive() || isArray()) {
3975 return new Class<?>[] { this };
3976 }
3977 Class<?>[] members = getNestMembers0();
3978 // Can't actually enable this due to bootstrapping issues
3979 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3980 return members;
3981 }
3982
3983 /**
3984 * Returns the descriptor string of the entity (class, interface, array class,
3985 * primitive type, or {@code void}) represented by this {@code Class} object.
3986 *
3987 * <p> If this {@code Class} object represents a class or interface,
3988 * not an array class, then:
3989 * <ul>
3990 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3991 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3992 * for the class or interface. Calling
3993 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3994 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3995 * describing this class or interface.
3996 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3997 * then the result is a string of the form:
3998 * <blockquote>
3999 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
4000 * </blockquote>
4001 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
4002 * encoded in internal form indicated by the {@code class} file passed to
4003 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
4004 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
4005 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
4006 * The result string is not a type descriptor.
4007 * </ul>
4008 *
4009 * <p> If this {@code Class} object represents an array class, then
4010 * the result is a string consisting of one or more '{@code [}' characters
4011 * representing the depth of the array nesting, followed by the
4012 * descriptor string of the element type.
4013 * <ul>
4014 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
4015 * or interface, then this array class can be described nominally.
4016 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
4017 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
4018 * describing this array class.
4019 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
4020 * interface, then this array class cannot be described nominally.
4021 * The result string is not a type descriptor.
4022 * </ul>
4023 *
4024 * <p> If this {@code Class} object represents a primitive type or
4025 * {@code void}, then the result is a field descriptor string which
4026 * is a one-letter code corresponding to a primitive type or {@code void}
4027 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
4028 *
4029 * @return the descriptor string for this {@code Class} object
4030 * @jvms 4.3.2 Field Descriptors
4031 * @since 12
4032 */
4033 @Override
4034 public String descriptorString() {
4035 if (isPrimitive())
4036 return Wrapper.forPrimitiveType(this).basicTypeString();
4037
4038 if (isArray()) {
4039 return "[".concat(componentType.descriptorString());
4040 } else if (isHidden()) {
4041 String name = getName();
4042 int index = name.indexOf('/');
4043 return new StringBuilder(name.length() + 2)
4044 .append('L')
4045 .append(name.substring(0, index).replace('.', '/'))
4046 .append('.')
4047 .append(name, index + 1, name.length())
4048 .append(';')
4049 .toString();
4050 } else {
4051 String name = getName().replace('.', '/');
4052 return StringConcatHelper.concat("L", name, ";");
4053 }
4054 }
4055
4056 /**
4057 * Returns the component type of this {@code Class}, if it describes
4058 * an array type, or {@code null} otherwise.
4059 *
4060 * @implSpec
4061 * Equivalent to {@link Class#getComponentType()}.
4062 *
4063 * @return a {@code Class} describing the component type, or {@code null}
4064 * if this {@code Class} does not describe an array type
4065 * @since 12
4066 */
4067 @Override
4068 public Class<?> componentType() {
4069 return getComponentType();
4070 }
4071
4072 /**
4073 * Returns a {@code Class} for an array type whose component type
4074 * is described by this {@linkplain Class}.
4075 *
4076 * @throws UnsupportedOperationException if this component type is {@linkplain
4077 * Void#TYPE void} or if the number of dimensions of the resulting array
4078 * type would exceed 255.
4079 * @return a {@code Class} describing the array type
4080 * @jvms 4.3.2 Field Descriptors
4081 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4082 * @since 12
4083 */
4084 @Override
4085 public Class<?> arrayType() {
4086 try {
4087 return Array.newInstance(this, 0).getClass();
4088 } catch (IllegalArgumentException iae) {
4089 throw new UnsupportedOperationException(iae);
4090 }
4091 }
4092
4093 /**
4094 * Returns a nominal descriptor for this instance, if one can be
4095 * constructed, or an empty {@link Optional} if one cannot be.
4096 *
4097 * @return An {@link Optional} containing the resulting nominal descriptor,
4098 * or an empty {@link Optional} if one cannot be constructed.
4099 * @since 12
4100 */
4101 @Override
4102 public Optional<ClassDesc> describeConstable() {
4103 Class<?> c = isArray() ? elementType() : this;
4104 return c.isHidden() ? Optional.empty()
4105 : Optional.of(ConstantUtils.classDesc(this));
4106 }
4107
4108 /**
4109 * Returns {@code true} if and only if the underlying class is a hidden class.
4110 *
4111 * @return {@code true} if and only if this class is a hidden class.
4112 *
4113 * @since 15
4114 * @see MethodHandles.Lookup#defineHiddenClass
4115 * @see Class##hiddenClasses Hidden Classes
4116 */
4117 @IntrinsicCandidate
4118 public native boolean isHidden();
4119
4120 /**
4121 * Returns an array containing {@code Class} objects representing the
4122 * direct subinterfaces or subclasses permitted to extend or
4123 * implement this class or interface if it is sealed. The order of such elements
4124 * is unspecified. The array is empty if this sealed class or interface has no
4125 * permitted subclass. If this {@code Class} object represents a primitive type,
4126 * {@code void}, an array type, or a class or interface that is not sealed,
4127 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4128 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4129 * returns a non-null value.
4130 *
4131 * For each class or interface {@code C} which is recorded as a permitted
4132 * direct subinterface or subclass of this class or interface,
4133 * this method attempts to obtain the {@code Class}
4134 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4135 * loader} of the current {@code Class} object).
4136 * The {@code Class} objects which can be obtained and which are direct
4137 * subinterfaces or subclasses of this class or interface,
4138 * are indicated by elements of the returned array. If a {@code Class} object
4139 * cannot be obtained, it is silently ignored, and not included in the result
4140 * array.
4141 *
4142 * @return an array of {@code Class} objects of the permitted subclasses of this class
4143 * or interface, or {@code null} if this class or interface is not sealed.
4144 *
4145 * @jls 8.1 Class Declarations
4146 * @jls 9.1 Interface Declarations
4147 * @since 17
4148 */
4149 public Class<?>[] getPermittedSubclasses() {
4150 Class<?>[] subClasses;
4151 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4152 return null;
4153 }
4154 if (subClasses.length > 0) {
4155 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4156 subClasses = Arrays.stream(subClasses)
4157 .filter(this::isDirectSubType)
4158 .toArray(s -> new Class<?>[s]);
4159 }
4160 }
4161 return subClasses;
4162 }
4163
4164 private boolean isDirectSubType(Class<?> c) {
4165 if (isInterface()) {
4166 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4167 if (i == this) {
4168 return true;
4169 }
4170 }
4171 } else {
4172 return c.getSuperclass() == this;
4173 }
4174 return false;
4175 }
4176
4177 /**
4178 * Returns {@code true} if and only if this {@code Class} object represents
4179 * a sealed class or interface. If this {@code Class} object represents a
4180 * primitive type, {@code void}, or an array type, this method returns
4181 * {@code false}. A sealed class or interface has (possibly zero) permitted
4182 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4183 * possibly empty value for a sealed class or interface.
4184 *
4185 * @return {@code true} if and only if this {@code Class} object represents
4186 * a sealed class or interface.
4187 *
4188 * @jls 8.1 Class Declarations
4189 * @jls 9.1 Interface Declarations
4190 * @since 17
4191 */
4192 public boolean isSealed() {
4193 if (isArray() || isPrimitive()) {
4194 return false;
4195 }
4196 return getPermittedSubclasses() != null;
4197 }
4198
4199 private native Class<?>[] getPermittedSubclasses0();
4200
4201 /*
4202 * Return the class's major and minor class file version packed into an int.
4203 * The high order 16 bits contain the class's minor version. The low order
4204 * 16 bits contain the class's major version.
4205 *
4206 * If the class is an array type then the class file version of its element
4207 * type is returned. If the class is a primitive type then the latest class
4208 * file major version is returned and zero is returned for the minor version.
4209 */
4210 /* package-private */
4211 int getClassFileVersion() {
4212 Class<?> c = isArray() ? elementType() : this;
4213 return c.getClassFileVersion0();
4214 }
4215
4216 private native int getClassFileVersion0();
4217
4218 /**
4219 * Return the access flags as they were in the class's bytecode, including
4220 * the original setting of ACC_SUPER.
4221 *
4222 * If this {@code Class} object represents a primitive type or
4223 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
4224 * {@code FINAL}.
4225 * If this {@code Class} object represents an array type, return 0.
4226 */
4227 int getClassFileAccessFlags() {
4228 return classFileAccessFlags;
4229 }
4230 }