1 /*
2 * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.constant.ClassDesc;
30 import java.lang.constant.ConstantDescs;
31 import java.lang.invoke.TypeDescriptor;
32 import java.lang.invoke.MethodHandles;
33 import java.lang.ref.SoftReference;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.ObjectStreamField;
37 import java.lang.reflect.AnnotatedElement;
38 import java.lang.reflect.AnnotatedType;
39 import java.lang.reflect.AccessFlag;
40 import java.lang.reflect.Array;
41 import java.lang.reflect.Constructor;
42 import java.lang.reflect.Executable;
43 import java.lang.reflect.Field;
44 import java.lang.reflect.GenericArrayType;
45 import java.lang.reflect.GenericDeclaration;
46 import java.lang.reflect.InvocationTargetException;
47 import java.lang.reflect.Member;
48 import java.lang.reflect.Method;
49 import java.lang.reflect.Modifier;
50 import java.lang.reflect.RecordComponent;
51 import java.lang.reflect.Type;
52 import java.lang.reflect.TypeVariable;
53 import java.lang.constant.Constable;
54 import java.net.URL;
55 import java.security.AllPermission;
56 import java.security.Permissions;
57 import java.security.ProtectionDomain;
58 import java.util.ArrayList;
59 import java.util.Arrays;
60 import java.util.Collection;
61 import java.util.HashMap;
62 import java.util.LinkedHashMap;
63 import java.util.LinkedHashSet;
64 import java.util.List;
65 import java.util.Map;
66 import java.util.Objects;
67 import java.util.Optional;
68 import java.util.Set;
69 import java.util.stream.Collectors;
70
71 import jdk.internal.constant.ConstantUtils;
72 import jdk.internal.loader.BootLoader;
73 import jdk.internal.loader.BuiltinClassLoader;
74 import jdk.internal.misc.Unsafe;
75 import jdk.internal.module.Resources;
76 import jdk.internal.reflect.CallerSensitive;
77 import jdk.internal.reflect.CallerSensitiveAdapter;
78 import jdk.internal.reflect.ConstantPool;
79 import jdk.internal.reflect.Reflection;
80 import jdk.internal.reflect.ReflectionFactory;
81 import jdk.internal.util.ModifiedUtf;
82 import jdk.internal.vm.annotation.AOTRuntimeSetup;
83 import jdk.internal.vm.annotation.AOTSafeClassInitializer;
84 import jdk.internal.vm.annotation.IntrinsicCandidate;
85 import jdk.internal.vm.annotation.Stable;
86
87 import sun.invoke.util.Wrapper;
88 import sun.reflect.generics.factory.CoreReflectionFactory;
89 import sun.reflect.generics.factory.GenericsFactory;
90 import sun.reflect.generics.repository.ClassRepository;
91 import sun.reflect.generics.repository.MethodRepository;
92 import sun.reflect.generics.repository.ConstructorRepository;
93 import sun.reflect.generics.scope.ClassScope;
94 import sun.reflect.annotation.*;
95
96 /**
97 * Instances of the class {@code Class} represent classes and
98 * interfaces in a running Java application. An enum class and a record
99 * class are kinds of class; an annotation interface is a kind of
100 * interface. Every array also belongs to a class that is reflected as
101 * a {@code Class} object that is shared by all arrays with the same
102 * element type and number of dimensions. The primitive Java types
103 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
104 * int}, {@code long}, {@code float}, and {@code double}), and the
105 * keyword {@code void} are also represented as {@code Class} objects.
106 *
107 * <p> {@code Class} has no public constructor. Instead a {@code Class}
108 * object is constructed automatically by the Java Virtual Machine when
109 * a class is derived from the bytes of a {@code class} file through
110 * the invocation of one of the following methods:
111 * <ul>
112 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
113 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
114 * java.lang.invoke.MethodHandles.Lookup::defineClass}
115 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
116 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
117 * </ul>
118 *
119 * <p> The methods of class {@code Class} expose many characteristics of a
120 * class or interface. Most characteristics are derived from the {@code class}
121 * file that the class loader passed to the Java Virtual Machine or
122 * from the {@code class} file passed to {@code Lookup::defineClass}
123 * or {@code Lookup::defineHiddenClass}.
124 * A few characteristics are determined by the class loading environment
125 * at run time, such as the module returned by {@link #getModule() getModule()}.
126 *
127 * <p> The following example uses a {@code Class} object to print the
128 * class name of an object:
129 *
130 * {@snippet lang="java" :
131 * void printClassName(Object obj) {
132 * System.out.println("The class of " + obj +
133 * " is " + obj.getClass().getName());
134 * }}
135 *
136 * It is also possible to get the {@code Class} object for a named
137 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
138 * (JLS {@jls 15.8.2}).
139 * For example:
140 *
141 * {@snippet lang="java" :
142 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
143 * }
144 *
145 * <p> Some methods of class {@code Class} expose whether the declaration of
146 * a class or interface in Java source code was <em>enclosed</em> within
147 * another declaration. Other methods describe how a class or interface
148 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
149 * classes and interfaces, in the same run-time package, that
150 * allow mutual access to their {@code private} members.
151 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
152 * (JVMS {@jvms 4.7.29}).
153 * One nestmate acts as the
154 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
155 * belong to the nest; each of them in turn records it as the nest host.
156 * The classes and interfaces which belong to a nest, including its host, are
157 * determined when
158 * {@code class} files are generated, for example, a Java compiler
159 * will typically record a top-level class as the host of a nest where the
160 * other members are the classes and interfaces whose declarations are
161 * enclosed within the top-level class declaration.
162 *
163 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
164 * A class or interface created by the invocation of
165 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
166 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
167 * class or interface.
168 * All kinds of class, including enum classes and record classes, may be
169 * hidden classes; all kinds of interface, including annotation interfaces,
170 * may be hidden interfaces.
171 *
172 * The {@linkplain #getName() name of a hidden class or interface} is
173 * not a {@linkplain ClassLoader##binary-name binary name},
174 * which means the following:
175 * <ul>
176 * <li>A hidden class or interface cannot be referenced by the constant pools
177 * of other classes and interfaces.
178 * <li>A hidden class or interface cannot be described in
179 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
180 * {@link #describeConstable() Class::describeConstable},
181 * {@link ClassDesc#of(String) ClassDesc::of}, or
182 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
183 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
184 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
185 * </ul>
186 *
187 * A hidden class or interface is never an array class, but may be
188 * the element type of an array. In all other respects, the fact that
189 * a class or interface is hidden has no bearing on the characteristics
190 * exposed by the methods of class {@code Class}.
191 *
192 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
193 *
194 * Conventionally, a Java compiler, starting from a source file for an
195 * implicitly declared class, say {@code HelloWorld.java}, creates a
196 * similarly-named {@code class} file, {@code HelloWorld.class}, where
197 * the class stored in that {@code class} file is named {@code
198 * "HelloWorld"}, matching the base names of the source and {@code
199 * class} files.
200 *
201 * For the {@code Class} object of an implicitly declared class {@code
202 * HelloWorld}, the methods to get the {@linkplain #getName name} and
203 * {@linkplain #getTypeName type name} return results
204 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
205 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
206 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
207 *
208 * @param <T> the type of the class modeled by this {@code Class}
209 * object. For example, the type of {@code String.class} is {@code
210 * Class<String>}. Use {@code Class<?>} if the class being modeled is
211 * unknown.
212 *
213 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
214 * @since 1.0
215 */
216 @AOTSafeClassInitializer
217 public final class Class<T> implements java.io.Serializable,
218 GenericDeclaration,
219 Type,
220 AnnotatedElement,
221 TypeDescriptor.OfField<Class<?>>,
222 Constable {
223 private static final int ANNOTATION= 0x00002000;
224 private static final int ENUM = 0x00004000;
225 private static final int SYNTHETIC = 0x00001000;
226
227 private static native void registerNatives();
228 static {
229 runtimeSetup();
230 }
231
232 /// No significant static final fields; [#resetArchivedStates()] handles
233 /// prevents storing [#reflectionFactory] into AOT image.
234 @AOTRuntimeSetup
235 private static void runtimeSetup() {
236 registerNatives();
237 }
238
239 /*
240 * Private constructor. Only the Java Virtual Machine creates Class objects.
241 * This constructor is not used and prevents the default constructor being
242 * generated.
243 */
244 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, char flags) {
245 // Initialize final field for classLoader. The initialization value of non-null
246 // prevents future JIT optimizations from assuming this final field is null.
247 // The following assignments are done directly by the VM without calling this constructor.
248 classLoader = loader;
249 componentType = arrayComponentType;
250 modifiers = mods;
251 protectionDomain = pd;
252 primitive = isPrim;
253 classFileAccessFlags = flags;
254 }
255
256 /**
257 * Converts the object to a string. The string representation is the
258 * string "class" or "interface", followed by a space, and then by the
259 * name of the class in the format returned by {@code getName}.
260 * If this {@code Class} object represents a primitive type,
261 * this method returns the name of the primitive type. If
262 * this {@code Class} object represents void this method returns
263 * "void". If this {@code Class} object represents an array type,
264 * this method returns "class " followed by {@code getName}.
265 *
266 * @return a string representation of this {@code Class} object.
267 */
268 public String toString() {
269 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
270 return kind.concat(getName());
271 }
272
273 /**
274 * Returns a string describing this {@code Class}, including
275 * information about modifiers, {@link #isSealed() sealed}/{@code
276 * non-sealed} status, and type parameters.
277 *
278 * The string is formatted as a list of type modifiers, if any,
279 * followed by the kind of type (empty string for primitive types
280 * and {@code class}, {@code enum}, {@code interface},
281 * {@code @interface}, or {@code record} as appropriate), followed
282 * by the type's name, followed by an angle-bracketed
283 * comma-separated list of the type's type parameters, if any,
284 * including informative bounds on the type parameters, if any.
285 *
286 * A space is used to separate modifiers from one another and to
287 * separate any modifiers from the kind of type. The modifiers
288 * occur in canonical order. If there are no type parameters, the
289 * type parameter list is elided.
290 *
291 * For an array type, the string starts with the type name,
292 * followed by an angle-bracketed comma-separated list of the
293 * type's type parameters, if any, followed by a sequence of
294 * {@code []} characters, one set of brackets per dimension of
295 * the array.
296 *
297 * <p>Note that since information about the runtime representation
298 * of a type is being generated, modifiers not present on the
299 * originating source code or illegal on the originating source
300 * code may be present.
301 *
302 * @return a string describing this {@code Class}, including
303 * information about modifiers and type parameters
304 *
305 * @since 1.8
306 */
307 public String toGenericString() {
308 if (isPrimitive()) {
309 return toString();
310 } else {
311 StringBuilder sb = new StringBuilder();
312 Class<?> component = this;
313 int arrayDepth = 0;
314
315 if (isArray()) {
316 do {
317 arrayDepth++;
318 component = component.getComponentType();
319 } while (component.isArray());
320 sb.append(component.getName());
321 } else {
322 // Class modifiers are a superset of interface modifiers
323 int modifiers = getModifiers() & Modifier.classModifiers();
324 if (modifiers != 0) {
325 sb.append(Modifier.toString(modifiers));
326 sb.append(' ');
327 }
328
329 // A class cannot be strictfp and sealed/non-sealed so
330 // it is sufficient to check for sealed-ness after all
331 // modifiers are printed.
332 addSealingInfo(modifiers, sb);
333
334 if (isAnnotation()) {
335 sb.append('@');
336 }
337 if (isInterface()) { // Note: all annotation interfaces are interfaces
338 sb.append("interface");
339 } else {
340 if (isEnum())
341 sb.append("enum");
342 else if (isRecord())
343 sb.append("record");
344 else
345 sb.append("class");
346 }
347 sb.append(' ');
348 sb.append(getName());
349 }
350
351 TypeVariable<?>[] typeparms = component.getTypeParameters();
352 if (typeparms.length > 0) {
353 sb.append(Arrays.stream(typeparms)
354 .map(Class::typeVarBounds)
355 .collect(Collectors.joining(",", "<", ">")));
356 }
357
358 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
359
360 return sb.toString();
361 }
362 }
363
364 private void addSealingInfo(int modifiers, StringBuilder sb) {
365 // A class can be final XOR sealed XOR non-sealed.
366 if (Modifier.isFinal(modifiers)) {
367 return; // no-op
368 } else {
369 if (isSealed()) {
370 sb.append("sealed ");
371 return;
372 } else {
373 // Check for sealed ancestor, which implies this class
374 // is non-sealed.
375 if (hasSealedAncestor(this)) {
376 sb.append("non-sealed ");
377 }
378 }
379 }
380 }
381
382 private boolean hasSealedAncestor(Class<?> clazz) {
383 // From JLS 8.1.1.2:
384 // "It is a compile-time error if a class has a sealed direct
385 // superclass or a sealed direct superinterface, and is not
386 // declared final, sealed, or non-sealed either explicitly or
387 // implicitly.
388 // Thus, an effect of the sealed keyword is to force all
389 // direct subclasses to explicitly declare whether they are
390 // final, sealed, or non-sealed. This avoids accidentally
391 // exposing a sealed class hierarchy to unwanted subclassing."
392
393 // Therefore, will just check direct superclass and
394 // superinterfaces.
395 var superclass = clazz.getSuperclass();
396 if (superclass != null && superclass.isSealed()) {
397 return true;
398 }
399 for (var superinterface : clazz.getInterfaces()) {
400 if (superinterface.isSealed()) {
401 return true;
402 }
403 }
404 return false;
405 }
406
407 static String typeVarBounds(TypeVariable<?> typeVar) {
408 Type[] bounds = typeVar.getBounds();
409 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
410 return typeVar.getName();
411 } else {
412 return typeVar.getName() + " extends " +
413 Arrays.stream(bounds)
414 .map(Type::getTypeName)
415 .collect(Collectors.joining(" & "));
416 }
417 }
418
419 /**
420 * Returns the {@code Class} object associated with the class or
421 * interface with the given string name. Invoking this method is
422 * equivalent to:
423 *
424 * {@snippet lang="java" :
425 * Class.forName(className, true, currentLoader)
426 * }
427 *
428 * where {@code currentLoader} denotes the defining class loader of
429 * the current class.
430 *
431 * <p> For example, the following code fragment returns the
432 * runtime {@code Class} object for the class named
433 * {@code java.lang.Thread}:
434 *
435 * {@snippet lang="java" :
436 * Class<?> t = Class.forName("java.lang.Thread");
437 * }
438 * <p>
439 * A call to {@code forName("X")} causes the class named
440 * {@code X} to be initialized.
441 *
442 * <p>
443 * In cases where this method is called from a context where there is no
444 * caller frame on the stack (e.g. when called directly from a JNI
445 * attached thread), the system class loader is used.
446 *
447 * @param className the {@linkplain ClassLoader##binary-name binary name}
448 * of the class or the string representing an array type
449 * @return the {@code Class} object for the class with the
450 * specified name.
451 * @throws LinkageError if the linkage fails
452 * @throws ExceptionInInitializerError if the initialization provoked
453 * by this method fails
454 * @throws ClassNotFoundException if the class cannot be located
455 *
456 * @jls 12.2 Loading of Classes and Interfaces
457 * @jls 12.3 Linking of Classes and Interfaces
458 * @jls 12.4 Initialization of Classes and Interfaces
459 */
460 @CallerSensitive
461 public static Class<?> forName(String className)
462 throws ClassNotFoundException {
463 Class<?> caller = Reflection.getCallerClass();
464 return forName(className, caller);
465 }
466
467 // Caller-sensitive adapter method for reflective invocation
468 @CallerSensitiveAdapter
469 private static Class<?> forName(String className, Class<?> caller)
470 throws ClassNotFoundException {
471 validateClassNameLength(className);
472 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
473 : ClassLoader.getClassLoader(caller);
474 return forName0(className, true, loader, caller);
475 }
476
477 /**
478 * Returns the {@code Class} object associated with the class or
479 * interface with the given string name, using the given class loader.
480 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
481 * this method attempts to locate and load the class or interface. The specified
482 * class loader is used to load the class or interface. If the parameter
483 * {@code loader} is {@code null}, the class is loaded through the bootstrap
484 * class loader. The class is initialized only if the
485 * {@code initialize} parameter is {@code true} and if it has
486 * not been initialized earlier.
487 *
488 * <p> This method cannot be used to obtain any of the {@code Class} objects
489 * representing primitive types or void, hidden classes or interfaces,
490 * or array classes whose element type is a hidden class or interface.
491 * If {@code name} denotes a primitive type or void, for example {@code I},
492 * an attempt will be made to locate a user-defined class in the unnamed package
493 * whose name is {@code I} instead.
494 * To obtain a {@code Class} object for a named primitive type
495 * such as {@code int} or {@code long} use {@link
496 * #forPrimitiveName(String)}.
497 *
498 * <p> To obtain the {@code Class} object associated with an array class,
499 * the name consists of one or more {@code '['} representing the depth
500 * of the array nesting, followed by the element type as encoded in
501 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
502 *
503 * <p> Examples:
504 * {@snippet lang="java" :
505 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
506 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
507 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
508 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
509 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
510 * }
511 *
512 * <p> A call to {@code getName()} on the {@code Class} object returned
513 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
514 *
515 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
516 * named <i>N</i> to be loaded but not initialized regardless of the value
517 * of the {@code initialize} parameter.
518 *
519 * @apiNote
520 * This method throws errors related to loading, linking or initializing
521 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
522 * <cite>The Java Language Specification</cite>.
523 * In addition, this method does not check whether the requested class
524 * is accessible to its caller.
525 *
526 * @param name the {@linkplain ClassLoader##binary-name binary name}
527 * of the class or the string representing an array class
528 *
529 * @param initialize if {@code true} the class will be initialized
530 * (which implies linking). See Section {@jls
531 * 12.4} of <cite>The Java Language
532 * Specification</cite>.
533 * @param loader class loader from which the class must be loaded
534 * @return class object representing the desired class
535 *
536 * @throws LinkageError if the linkage fails
537 * @throws ExceptionInInitializerError if the initialization provoked
538 * by this method fails
539 * @throws ClassNotFoundException if the class cannot be located by
540 * the specified class loader
541 *
542 * @see java.lang.Class#forName(String)
543 * @see java.lang.ClassLoader
544 *
545 * @jls 12.2 Loading of Classes and Interfaces
546 * @jls 12.3 Linking of Classes and Interfaces
547 * @jls 12.4 Initialization of Classes and Interfaces
548 * @jls 13.1 The Form of a Binary
549 * @since 1.2
550 */
551 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
552 throws ClassNotFoundException
553 {
554 validateClassNameLength(name);
555 return forName0(name, initialize, loader, null);
556 }
557
558 /** Called after security check for system loader access checks have been made. */
559 private static native Class<?> forName0(String name, boolean initialize,
560 ClassLoader loader,
561 Class<?> caller)
562 throws ClassNotFoundException;
563
564
565 /**
566 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
567 * binary name} in the given module.
568 *
569 * <p> This method attempts to locate and load the class or interface.
570 * It does not link the class, and does not run the class initializer.
571 * If the class is not found, this method returns {@code null}. </p>
572 *
573 * <p> If the class loader of the given module defines other modules and
574 * the given name is a class defined in a different module, this method
575 * returns {@code null} after the class is loaded. </p>
576 *
577 * <p> This method does not check whether the requested class is
578 * accessible to its caller. </p>
579 *
580 * @apiNote
581 * This method does not support loading of array types, unlike
582 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
583 * a binary name. This method returns {@code null} on failure rather than
584 * throwing a {@link ClassNotFoundException}, as is done by
585 * the {@link #forName(String, boolean, ClassLoader)} method.
586 *
587 * @param module A module
588 * @param name The {@linkplain ClassLoader##binary-name binary name}
589 * of the class
590 * @return {@code Class} object of the given name defined in the given module;
591 * {@code null} if not found.
592 *
593 * @throws NullPointerException if the given module or name is {@code null}
594 *
595 * @throws LinkageError if the linkage fails
596 *
597 * @jls 12.2 Loading of Classes and Interfaces
598 * @jls 12.3 Linking of Classes and Interfaces
599 * @since 9
600 */
601 public static Class<?> forName(Module module, String name) {
602 Objects.requireNonNull(module);
603 Objects.requireNonNull(name);
604 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
605 return null;
606 }
607
608 ClassLoader cl = module.getClassLoader();
609 if (cl != null) {
610 return cl.loadClass(module, name);
611 } else {
612 return BootLoader.loadClass(module, name);
613 }
614 }
615
616 /**
617 * {@return the {@code Class} object associated with the
618 * {@linkplain #isPrimitive() primitive type} of the given name}
619 * If the argument is not the name of a primitive type, {@code
620 * null} is returned.
621 *
622 * @param primitiveName the name of the primitive type to find
623 *
624 * @throws NullPointerException if the argument is {@code null}
625 *
626 * @jls 4.2 Primitive Types and Values
627 * @jls 15.8.2 Class Literals
628 * @since 22
629 */
630 public static Class<?> forPrimitiveName(String primitiveName) {
631 return switch(primitiveName) {
632 // Integral types
633 case "int" -> int.class;
634 case "long" -> long.class;
635 case "short" -> short.class;
636 case "char" -> char.class;
637 case "byte" -> byte.class;
638
639 // Floating-point types
640 case "float" -> float.class;
641 case "double" -> double.class;
642
643 // Other types
644 case "boolean" -> boolean.class;
645 case "void" -> void.class;
646
647 default -> null;
648 };
649 }
650
651 /**
652 * Creates a new instance of the class represented by this {@code Class}
653 * object. The class is instantiated as if by a {@code new}
654 * expression with an empty argument list. The class is initialized if it
655 * has not already been initialized.
656 *
657 * @deprecated This method propagates any exception thrown by the
658 * nullary constructor, including a checked exception. Use of
659 * this method effectively bypasses the compile-time exception
660 * checking that would otherwise be performed by the compiler.
661 * The {@link
662 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
663 * Constructor.newInstance} method avoids this problem by wrapping
664 * any exception thrown by the constructor in a (checked) {@link
665 * java.lang.reflect.InvocationTargetException}.
666 *
667 * <p>The call
668 *
669 * {@snippet lang="java" :
670 * clazz.newInstance()
671 * }
672 *
673 * can be replaced by
674 *
675 * {@snippet lang="java" :
676 * clazz.getDeclaredConstructor().newInstance()
677 * }
678 *
679 * The latter sequence of calls is inferred to be able to throw
680 * the additional exception types {@link
681 * InvocationTargetException} and {@link
682 * NoSuchMethodException}. Both of these exception types are
683 * subclasses of {@link ReflectiveOperationException}.
684 *
685 * @return a newly allocated instance of the class represented by this
686 * object.
687 * @throws IllegalAccessException if the class or its nullary
688 * constructor is not accessible.
689 * @throws InstantiationException
690 * if this {@code Class} represents an abstract class,
691 * an interface, an array class, a primitive type, or void;
692 * or if the class has no nullary constructor;
693 * or if the instantiation fails for some other reason.
694 * @throws ExceptionInInitializerError if the initialization
695 * provoked by this method fails.
696 */
697 @CallerSensitive
698 @Deprecated(since="9")
699 public T newInstance()
700 throws InstantiationException, IllegalAccessException
701 {
702 // Constructor lookup
703 Constructor<T> tmpConstructor = cachedConstructor;
704 if (tmpConstructor == null) {
705 if (this == Class.class) {
706 throw new IllegalAccessException(
707 "Can not call newInstance() on the Class for java.lang.Class"
708 );
709 }
710 try {
711 Class<?>[] empty = {};
712 final Constructor<T> c = getReflectionFactory().copyConstructor(
713 getConstructor0(empty, Member.DECLARED));
714 // Disable accessibility checks on the constructor
715 // access check is done with the true caller
716 c.setAccessible(true);
717 cachedConstructor = tmpConstructor = c;
718 } catch (NoSuchMethodException e) {
719 throw (InstantiationException)
720 new InstantiationException(getName()).initCause(e);
721 }
722 }
723
724 try {
725 Class<?> caller = Reflection.getCallerClass();
726 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
727 } catch (InvocationTargetException e) {
728 Unsafe.getUnsafe().throwException(e.getTargetException());
729 // Not reached
730 return null;
731 }
732 }
733
734 private transient volatile Constructor<T> cachedConstructor;
735
736 /**
737 * Determines if the specified {@code Object} is assignment-compatible
738 * with the object represented by this {@code Class}. This method is
739 * the dynamic equivalent of the Java language {@code instanceof}
740 * operator. The method returns {@code true} if the specified
741 * {@code Object} argument is non-null and can be cast to the
742 * reference type represented by this {@code Class} object without
743 * raising a {@code ClassCastException.} It returns {@code false}
744 * otherwise.
745 *
746 * <p> Specifically, if this {@code Class} object represents a
747 * declared class, this method returns {@code true} if the specified
748 * {@code Object} argument is an instance of the represented class (or
749 * of any of its subclasses); it returns {@code false} otherwise. If
750 * this {@code Class} object represents an array class, this method
751 * returns {@code true} if the specified {@code Object} argument
752 * can be converted to an object of the array class by an identity
753 * conversion or by a widening reference conversion; it returns
754 * {@code false} otherwise. If this {@code Class} object
755 * represents an interface, this method returns {@code true} if the
756 * class or any superclass of the specified {@code Object} argument
757 * implements this interface; it returns {@code false} otherwise. If
758 * this {@code Class} object represents a primitive type, this method
759 * returns {@code false}.
760 *
761 * @param obj the object to check
762 * @return true if {@code obj} is an instance of this class
763 *
764 * @since 1.1
765 */
766 @IntrinsicCandidate
767 public native boolean isInstance(Object obj);
768
769
770 /**
771 * Determines if the class or interface represented by this
772 * {@code Class} object is either the same as, or is a superclass or
773 * superinterface of, the class or interface represented by the specified
774 * {@code Class} parameter. It returns {@code true} if so;
775 * otherwise it returns {@code false}. If this {@code Class}
776 * object represents a primitive type, this method returns
777 * {@code true} if the specified {@code Class} parameter is
778 * exactly this {@code Class} object; otherwise it returns
779 * {@code false}.
780 *
781 * <p> Specifically, this method tests whether the type represented by the
782 * specified {@code Class} parameter can be converted to the type
783 * represented by this {@code Class} object via an identity conversion
784 * or via a widening reference conversion. See <cite>The Java Language
785 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
786 * for details.
787 *
788 * @param cls the {@code Class} object to be checked
789 * @return the {@code boolean} value indicating whether objects of the
790 * type {@code cls} can be assigned to objects of this class
791 * @throws NullPointerException if the specified Class parameter is
792 * null.
793 * @since 1.1
794 */
795 @IntrinsicCandidate
796 public native boolean isAssignableFrom(Class<?> cls);
797
798
799 /**
800 * Determines if this {@code Class} object represents an
801 * interface type.
802 *
803 * @return {@code true} if this {@code Class} object represents an interface;
804 * {@code false} otherwise.
805 */
806 public boolean isInterface() {
807 return Modifier.isInterface(modifiers);
808 }
809
810
811 /**
812 * Determines if this {@code Class} object represents an array class.
813 *
814 * @return {@code true} if this {@code Class} object represents an array class;
815 * {@code false} otherwise.
816 * @since 1.1
817 */
818 public boolean isArray() {
819 return componentType != null;
820 }
821
822
823 /**
824 * Determines if this {@code Class} object represents a primitive
825 * type or void.
826 *
827 * <p> There are nine predefined {@code Class} objects to
828 * represent the eight primitive types and void. These are
829 * created by the Java Virtual Machine, and have the same
830 * {@linkplain #getName() names} as the primitive types that they
831 * represent, namely {@code boolean}, {@code byte}, {@code char},
832 * {@code short}, {@code int}, {@code long}, {@code float}, and
833 * {@code double}.
834 *
835 * <p>No other class objects are considered primitive.
836 *
837 * @apiNote
838 * A {@code Class} object represented by a primitive type can be
839 * accessed via the {@code TYPE} public static final variables
840 * defined in the primitive wrapper classes such as {@link
841 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
842 * language, the objects may be referred to by a class literal
843 * expression such as {@code int.class}. The {@code Class} object
844 * for void can be expressed as {@code void.class} or {@link
845 * java.lang.Void#TYPE Void.TYPE}.
846 *
847 * @return true if and only if this class represents a primitive type
848 *
849 * @see java.lang.Boolean#TYPE
850 * @see java.lang.Character#TYPE
851 * @see java.lang.Byte#TYPE
852 * @see java.lang.Short#TYPE
853 * @see java.lang.Integer#TYPE
854 * @see java.lang.Long#TYPE
855 * @see java.lang.Float#TYPE
856 * @see java.lang.Double#TYPE
857 * @see java.lang.Void#TYPE
858 * @since 1.1
859 * @jls 15.8.2 Class Literals
860 */
861 public boolean isPrimitive() {
862 return primitive;
863 }
864
865 /**
866 * Returns true if this {@code Class} object represents an annotation
867 * interface. Note that if this method returns true, {@link #isInterface()}
868 * would also return true, as all annotation interfaces are also interfaces.
869 *
870 * @return {@code true} if this {@code Class} object represents an annotation
871 * interface; {@code false} otherwise
872 * @since 1.5
873 */
874 public boolean isAnnotation() {
875 return (getModifiers() & ANNOTATION) != 0;
876 }
877
878 /**
879 *{@return {@code true} if and only if this class has the synthetic modifier
880 * bit set}
881 *
882 * @jls 13.1 The Form of a Binary
883 * @jvms 4.1 The {@code ClassFile} Structure
884 * @see <a
885 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
886 * programming language and JVM modeling in core reflection</a>
887 * @since 1.5
888 */
889 public boolean isSynthetic() {
890 return (getModifiers() & SYNTHETIC) != 0;
891 }
892
893 /**
894 * Returns the name of the entity (class, interface, array class,
895 * primitive type, or void) represented by this {@code Class} object.
896 *
897 * <p> If this {@code Class} object represents a class or interface,
898 * not an array class, then:
899 * <ul>
900 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
901 * then the {@linkplain ClassLoader##binary-name binary name}
902 * of the class or interface is returned.
903 * <li> If the class or interface is hidden, then the result is a string
904 * of the form: {@code N + '/' + <suffix>}
905 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
906 * indicated by the {@code class} file passed to
907 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
908 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
909 * </ul>
910 *
911 * <p> If this {@code Class} object represents an array class, then
912 * the result is a string consisting of one or more '{@code [}' characters
913 * representing the depth of the array nesting, followed by the element
914 * type as encoded using the following table:
915 *
916 * <blockquote><table class="striped" id="nameFormat">
917 * <caption style="display:none">Element types and encodings</caption>
918 * <thead>
919 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
920 * </thead>
921 * <tbody style="text-align:left">
922 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
923 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
924 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
925 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
926 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
927 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
928 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
929 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
930 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
931 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
932 * </tbody>
933 * </table></blockquote>
934 *
935 * <p> If this {@code Class} object represents a primitive type or {@code void},
936 * then the result is a string with the same spelling as the Java language
937 * keyword which corresponds to the primitive type or {@code void}.
938 *
939 * <p> Examples:
940 * <blockquote><pre>
941 * String.class.getName()
942 * returns "java.lang.String"
943 * Character.UnicodeBlock.class.getName()
944 * returns "java.lang.Character$UnicodeBlock"
945 * byte.class.getName()
946 * returns "byte"
947 * (new Object[3]).getClass().getName()
948 * returns "[Ljava.lang.Object;"
949 * (new int[3][4][5][6][7][8][9]).getClass().getName()
950 * returns "[[[[[[[I"
951 * </pre></blockquote>
952 *
953 * @apiNote
954 * Distinct class objects can have the same name but different class loaders.
955 *
956 * @return the name of the class, interface, or other entity
957 * represented by this {@code Class} object.
958 * @jls 13.1 The Form of a Binary
959 */
960 public String getName() {
961 String name = this.name;
962 return name != null ? name : initClassName();
963 }
964
965 // Cache the name to reduce the number of calls into the VM.
966 // This field would be set by VM itself during initClassName call.
967 private transient String name;
968 private native String initClassName();
969
970 /**
971 * Returns the class loader for the class. Some implementations may use
972 * null to represent the bootstrap class loader. This method will return
973 * null in such implementations if this class was loaded by the bootstrap
974 * class loader.
975 *
976 * <p>If this {@code Class} object
977 * represents a primitive type or void, null is returned.
978 *
979 * @return the class loader that loaded the class or interface
980 * represented by this {@code Class} object.
981 * @see java.lang.ClassLoader
982 */
983 public ClassLoader getClassLoader() {
984 return classLoader;
985 }
986
987 // Package-private to allow ClassLoader access
988 ClassLoader getClassLoader0() { return classLoader; }
989
990 /**
991 * Returns the module that this class or interface is a member of.
992 *
993 * If this class represents an array type then this method returns the
994 * {@code Module} for the element type. If this class represents a
995 * primitive type or void, then the {@code Module} object for the
996 * {@code java.base} module is returned.
997 *
998 * If this class is in an unnamed module then the {@linkplain
999 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1000 * loader for this class is returned.
1001 *
1002 * @return the module that this class or interface is a member of
1003 *
1004 * @since 9
1005 */
1006 public Module getModule() {
1007 return module;
1008 }
1009
1010 // set by VM
1011 @Stable
1012 private transient Module module;
1013
1014 // Initialized in JVM not by private constructor
1015 // This field is filtered from reflection access, i.e. getDeclaredField
1016 // will throw NoSuchFieldException
1017 private final ClassLoader classLoader;
1018
1019 private transient Object classData; // Set by VM
1020 private transient Object[] signers; // Read by VM, mutable
1021 private final transient char modifiers; // Set by the VM
1022 private final transient char classFileAccessFlags; // Set by the VM
1023 private final transient boolean primitive; // Set by the VM if the Class is a primitive type.
1024
1025 // package-private
1026 Object getClassData() {
1027 return classData;
1028 }
1029
1030 /**
1031 * Returns an array of {@code TypeVariable} objects that represent the
1032 * type variables declared by the generic declaration represented by this
1033 * {@code GenericDeclaration} object, in declaration order. Returns an
1034 * array of length 0 if the underlying generic declaration declares no type
1035 * variables.
1036 *
1037 * @return an array of {@code TypeVariable} objects that represent
1038 * the type variables declared by this generic declaration
1039 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1040 * signature of this generic declaration does not conform to
1041 * the format specified in section {@jvms 4.7.9} of
1042 * <cite>The Java Virtual Machine Specification</cite>
1043 * @since 1.5
1044 */
1045 @SuppressWarnings("unchecked")
1046 public TypeVariable<Class<T>>[] getTypeParameters() {
1047 ClassRepository info = getGenericInfo();
1048 if (info != null)
1049 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1050 else
1051 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1052 }
1053
1054
1055 /**
1056 * Returns the {@code Class} representing the direct superclass of the
1057 * entity (class, interface, primitive type or void) represented by
1058 * this {@code Class}. If this {@code Class} represents either the
1059 * {@code Object} class, an interface, a primitive type, or void, then
1060 * null is returned. If this {@code Class} object represents an array class
1061 * then the {@code Class} object representing the {@code Object} class is
1062 * returned.
1063 *
1064 * @return the direct superclass of the class represented by this {@code Class} object
1065 */
1066 @IntrinsicCandidate
1067 public native Class<? super T> getSuperclass();
1068
1069
1070 /**
1071 * Returns the {@code Type} representing the direct superclass of
1072 * the entity (class, interface, primitive type or void) represented by
1073 * this {@code Class} object.
1074 *
1075 * <p>If the superclass is a parameterized type, the {@code Type}
1076 * object returned must accurately reflect the actual type
1077 * arguments used in the source code. The parameterized type
1078 * representing the superclass is created if it had not been
1079 * created before. See the declaration of {@link
1080 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1081 * semantics of the creation process for parameterized types. If
1082 * this {@code Class} object represents either the {@code Object}
1083 * class, an interface, a primitive type, or void, then null is
1084 * returned. If this {@code Class} object represents an array class
1085 * then the {@code Class} object representing the {@code Object} class is
1086 * returned.
1087 *
1088 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1089 * class signature does not conform to the format specified in
1090 * section {@jvms 4.7.9} of <cite>The Java Virtual
1091 * Machine Specification</cite>
1092 * @throws TypeNotPresentException if the generic superclass
1093 * refers to a non-existent type declaration
1094 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1095 * generic superclass refers to a parameterized type that cannot be
1096 * instantiated for any reason
1097 * @return the direct superclass of the class represented by this {@code Class} object
1098 * @since 1.5
1099 */
1100 public Type getGenericSuperclass() {
1101 ClassRepository info = getGenericInfo();
1102 if (info == null) {
1103 return getSuperclass();
1104 }
1105
1106 // Historical irregularity:
1107 // Generic signature marks interfaces with superclass = Object
1108 // but this API returns null for interfaces
1109 if (isInterface()) {
1110 return null;
1111 }
1112
1113 return info.getSuperclass();
1114 }
1115
1116 /**
1117 * Gets the package of this class.
1118 *
1119 * <p>If this class represents an array type, a primitive type or void,
1120 * this method returns {@code null}.
1121 *
1122 * @return the package of this class.
1123 */
1124 public Package getPackage() {
1125 if (isPrimitive() || isArray()) {
1126 return null;
1127 }
1128 ClassLoader cl = classLoader;
1129 return cl != null ? cl.definePackage(this)
1130 : BootLoader.definePackage(this);
1131 }
1132
1133 /**
1134 * Returns the fully qualified package name.
1135 *
1136 * <p> If this class is a top level class, then this method returns the fully
1137 * qualified name of the package that the class is a member of, or the
1138 * empty string if the class is in an unnamed package.
1139 *
1140 * <p> If this class is a member class, then this method is equivalent to
1141 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1142 * enclosing class}.
1143 *
1144 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1145 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1146 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1147 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1148 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1149 *
1150 * <p> If this class represents an array type then this method returns the
1151 * package name of the element type. If this class represents a primitive
1152 * type or void then the package name "{@code java.lang}" is returned.
1153 *
1154 * @return the fully qualified package name
1155 *
1156 * @since 9
1157 * @jls 6.7 Fully Qualified Names and Canonical Names
1158 */
1159 public String getPackageName() {
1160 String pn = this.packageName;
1161 if (pn == null) {
1162 Class<?> c = isArray() ? elementType() : this;
1163 if (c.isPrimitive()) {
1164 pn = "java.lang";
1165 } else {
1166 String cn = c.getName();
1167 int dot = cn.lastIndexOf('.');
1168 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1169 }
1170 this.packageName = pn;
1171 }
1172 return pn;
1173 }
1174
1175 // cached package name
1176 private transient String packageName;
1177
1178 /**
1179 * Returns the interfaces directly implemented by the class or interface
1180 * represented by this {@code Class} object.
1181 *
1182 * <p>If this {@code Class} object represents a class, the return value is an array
1183 * containing objects representing all interfaces directly implemented by
1184 * the class. The order of the interface objects in the array corresponds
1185 * to the order of the interface names in the {@code implements} clause of
1186 * the declaration of the class represented by this {@code Class} object. For example,
1187 * given the declaration:
1188 * <blockquote>
1189 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1190 * </blockquote>
1191 * suppose the value of {@code s} is an instance of
1192 * {@code Shimmer}; the value of the expression:
1193 * <blockquote>
1194 * {@code s.getClass().getInterfaces()[0]}
1195 * </blockquote>
1196 * is the {@code Class} object that represents interface
1197 * {@code FloorWax}; and the value of:
1198 * <blockquote>
1199 * {@code s.getClass().getInterfaces()[1]}
1200 * </blockquote>
1201 * is the {@code Class} object that represents interface
1202 * {@code DessertTopping}.
1203 *
1204 * <p>If this {@code Class} object represents an interface, the array contains objects
1205 * representing all interfaces directly extended by the interface. The
1206 * order of the interface objects in the array corresponds to the order of
1207 * the interface names in the {@code extends} clause of the declaration of
1208 * the interface represented by this {@code Class} object.
1209 *
1210 * <p>If this {@code Class} object represents a class or interface that implements no
1211 * interfaces, the method returns an array of length 0.
1212 *
1213 * <p>If this {@code Class} object represents a primitive type or void, the method
1214 * returns an array of length 0.
1215 *
1216 * <p>If this {@code Class} object represents an array type, the
1217 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1218 * returned in that order.
1219 *
1220 * @return an array of interfaces directly implemented by this class
1221 */
1222 public Class<?>[] getInterfaces() {
1223 // defensively copy before handing over to user code
1224 return getInterfaces(true);
1225 }
1226
1227 private Class<?>[] getInterfaces(boolean cloneArray) {
1228 ReflectionData<T> rd = reflectionData();
1229 Class<?>[] interfaces = rd.interfaces;
1230 if (interfaces == null) {
1231 interfaces = getInterfaces0();
1232 rd.interfaces = interfaces;
1233 }
1234 // defensively copy if requested
1235 return cloneArray ? interfaces.clone() : interfaces;
1236 }
1237
1238 private native Class<?>[] getInterfaces0();
1239
1240 /**
1241 * Returns the {@code Type}s representing the interfaces
1242 * directly implemented by the class or interface represented by
1243 * this {@code Class} object.
1244 *
1245 * <p>If a superinterface is a parameterized type, the
1246 * {@code Type} object returned for it must accurately reflect
1247 * the actual type arguments used in the source code. The
1248 * parameterized type representing each superinterface is created
1249 * if it had not been created before. See the declaration of
1250 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1251 * for the semantics of the creation process for parameterized
1252 * types.
1253 *
1254 * <p>If this {@code Class} object represents a class, the return value is an array
1255 * containing objects representing all interfaces directly implemented by
1256 * the class. The order of the interface objects in the array corresponds
1257 * to the order of the interface names in the {@code implements} clause of
1258 * the declaration of the class represented by this {@code Class} object.
1259 *
1260 * <p>If this {@code Class} object represents an interface, the array contains objects
1261 * representing all interfaces directly extended by the interface. The
1262 * order of the interface objects in the array corresponds to the order of
1263 * the interface names in the {@code extends} clause of the declaration of
1264 * the interface represented by this {@code Class} object.
1265 *
1266 * <p>If this {@code Class} object represents a class or interface that implements no
1267 * interfaces, the method returns an array of length 0.
1268 *
1269 * <p>If this {@code Class} object represents a primitive type or void, the method
1270 * returns an array of length 0.
1271 *
1272 * <p>If this {@code Class} object represents an array type, the
1273 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1274 * returned in that order.
1275 *
1276 * @throws java.lang.reflect.GenericSignatureFormatError
1277 * if the generic class signature does not conform to the
1278 * format specified in section {@jvms 4.7.9} of <cite>The
1279 * Java Virtual Machine Specification</cite>
1280 * @throws TypeNotPresentException if any of the generic
1281 * superinterfaces refers to a non-existent type declaration
1282 * @throws java.lang.reflect.MalformedParameterizedTypeException
1283 * if any of the generic superinterfaces refer to a parameterized
1284 * type that cannot be instantiated for any reason
1285 * @return an array of interfaces directly implemented by this class
1286 * @since 1.5
1287 */
1288 public Type[] getGenericInterfaces() {
1289 ClassRepository info = getGenericInfo();
1290 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1291 }
1292
1293
1294 /**
1295 * Returns the {@code Class} representing the component type of an
1296 * array. If this class does not represent an array class this method
1297 * returns null.
1298 *
1299 * @return the {@code Class} representing the component type of this
1300 * class if this class is an array
1301 * @see java.lang.reflect.Array
1302 * @since 1.1
1303 */
1304 public Class<?> getComponentType() {
1305 return componentType;
1306 }
1307
1308 // The componentType field's null value is the sole indication that the class
1309 // is an array - see isArray().
1310 private transient final Class<?> componentType;
1311
1312 /*
1313 * Returns the {@code Class} representing the element type of an array class.
1314 * If this class does not represent an array class, then this method returns
1315 * {@code null}.
1316 */
1317 private Class<?> elementType() {
1318 if (!isArray()) return null;
1319
1320 Class<?> c = this;
1321 while (c.isArray()) {
1322 c = c.getComponentType();
1323 }
1324 return c;
1325 }
1326
1327 /**
1328 * Returns the Java language modifiers for this class or interface, encoded
1329 * in an integer. The modifiers consist of the Java Virtual Machine's
1330 * constants for {@code public}, {@code protected},
1331 * {@code private}, {@code final}, {@code static},
1332 * {@code abstract} and {@code interface}; they should be decoded
1333 * using the methods of class {@code Modifier}.
1334 *
1335 * <p> If the underlying class is an array class:
1336 * <ul>
1337 * <li> its {@code public}, {@code private} and {@code protected}
1338 * modifiers are the same as those of its component type
1339 * <li> its {@code abstract} and {@code final} modifiers are always
1340 * {@code true}
1341 * <li> its interface modifier is always {@code false}, even when
1342 * the component type is an interface
1343 * </ul>
1344 * If this {@code Class} object represents a primitive type or
1345 * void, its {@code public}, {@code abstract}, and {@code final}
1346 * modifiers are always {@code true}.
1347 * For {@code Class} objects representing void, primitive types, and
1348 * arrays, the values of other modifiers are {@code false} other
1349 * than as specified above.
1350 *
1351 * <p> The modifier encodings are defined in section {@jvms 4.1}
1352 * of <cite>The Java Virtual Machine Specification</cite>.
1353 *
1354 * @return the {@code int} representing the modifiers for this class
1355 * @see java.lang.reflect.Modifier
1356 * @see #accessFlags()
1357 * @see <a
1358 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1359 * programming language and JVM modeling in core reflection</a>
1360 * @since 1.1
1361 * @jls 8.1.1 Class Modifiers
1362 * @jls 9.1.1 Interface Modifiers
1363 * @jvms 4.1 The {@code ClassFile} Structure
1364 */
1365 public int getModifiers() { return modifiers; }
1366
1367 /**
1368 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1369 * flags} for this class, possibly empty}
1370 *
1371 * <p> If the underlying class is an array class:
1372 * <ul>
1373 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1374 * access flags are the same as those of its component type
1375 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1376 * <li> its {@code INTERFACE} flag is absent, even when the
1377 * component type is an interface
1378 * </ul>
1379 * If this {@code Class} object represents a primitive type or
1380 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1381 * {@code FINAL}.
1382 * For {@code Class} objects representing void, primitive types, and
1383 * arrays, access flags are absent other than as specified above.
1384 *
1385 * @see #getModifiers()
1386 * @jvms 4.1 The ClassFile Structure
1387 * @jvms 4.7.6 The InnerClasses Attribute
1388 * @since 20
1389 */
1390 public Set<AccessFlag> accessFlags() {
1391 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1392 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1393 // and STATIC, which are not allowed on Location.CLASS.
1394 // Use getClassFileAccessFlags to expose SUPER status.
1395 var location = (isMemberClass() || isLocalClass() ||
1396 isAnonymousClass() || isArray()) ?
1397 AccessFlag.Location.INNER_CLASS :
1398 AccessFlag.Location.CLASS;
1399 return getReflectionFactory().parseAccessFlags((location == AccessFlag.Location.CLASS) ?
1400 getClassFileAccessFlags() : getModifiers(), location, this);
1401 }
1402
1403 /**
1404 * Gets the signers of this class.
1405 *
1406 * @return the signers of this class, or null if there are no signers. In
1407 * particular, this method returns null if this {@code Class} object represents
1408 * a primitive type or void.
1409 * @since 1.1
1410 */
1411 public Object[] getSigners() {
1412 var signers = this.signers;
1413 return signers == null ? null : signers.clone();
1414 }
1415
1416 /**
1417 * Set the signers of this class.
1418 */
1419 void setSigners(Object[] signers) {
1420 if (!isPrimitive() && !isArray()) {
1421 this.signers = signers;
1422 }
1423 }
1424
1425 /**
1426 * If this {@code Class} object represents a local or anonymous
1427 * class within a method, returns a {@link
1428 * java.lang.reflect.Method Method} object representing the
1429 * immediately enclosing method of the underlying class. Returns
1430 * {@code null} otherwise.
1431 *
1432 * In particular, this method returns {@code null} if the underlying
1433 * class is a local or anonymous class immediately enclosed by a class or
1434 * interface declaration, instance initializer or static initializer.
1435 *
1436 * @return the immediately enclosing method of the underlying class, if
1437 * that class is a local or anonymous class; otherwise {@code null}.
1438 *
1439 * @since 1.5
1440 */
1441 public Method getEnclosingMethod() {
1442 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1443
1444 if (enclosingInfo == null)
1445 return null;
1446 else {
1447 if (!enclosingInfo.isMethod())
1448 return null;
1449
1450 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1451 getFactory());
1452 Class<?> returnType = toClass(typeInfo.getReturnType());
1453 Type [] parameterTypes = typeInfo.getParameterTypes();
1454 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1455
1456 // Convert Types to Classes; returned types *should*
1457 // be class objects since the methodDescriptor's used
1458 // don't have generics information
1459 for(int i = 0; i < parameterClasses.length; i++)
1460 parameterClasses[i] = toClass(parameterTypes[i]);
1461
1462 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1463 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1464
1465 /*
1466 * Loop over all declared methods; match method name,
1467 * number of and type of parameters, *and* return
1468 * type. Matching return type is also necessary
1469 * because of covariant returns, etc.
1470 */
1471 ReflectionFactory fact = getReflectionFactory();
1472 for (Method m : candidates) {
1473 if (m.getName().equals(enclosingInfo.getName()) &&
1474 arrayContentsEq(parameterClasses,
1475 fact.getExecutableSharedParameterTypes(m))) {
1476 // finally, check return type
1477 if (m.getReturnType().equals(returnType)) {
1478 return fact.copyMethod(m);
1479 }
1480 }
1481 }
1482
1483 throw new InternalError("Enclosing method not found");
1484 }
1485 }
1486
1487 private native Object[] getEnclosingMethod0();
1488
1489 private EnclosingMethodInfo getEnclosingMethodInfo() {
1490 Object[] enclosingInfo = getEnclosingMethod0();
1491 if (enclosingInfo == null)
1492 return null;
1493 else {
1494 return new EnclosingMethodInfo(enclosingInfo);
1495 }
1496 }
1497
1498 private static final class EnclosingMethodInfo {
1499 private final Class<?> enclosingClass;
1500 private final String name;
1501 private final String descriptor;
1502
1503 static void validate(Object[] enclosingInfo) {
1504 if (enclosingInfo.length != 3)
1505 throw new InternalError("Malformed enclosing method information");
1506 try {
1507 // The array is expected to have three elements:
1508
1509 // the immediately enclosing class
1510 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1511 assert(enclosingClass != null);
1512
1513 // the immediately enclosing method or constructor's
1514 // name (can be null).
1515 String name = (String)enclosingInfo[1];
1516
1517 // the immediately enclosing method or constructor's
1518 // descriptor (null iff name is).
1519 String descriptor = (String)enclosingInfo[2];
1520 assert((name != null && descriptor != null) || name == descriptor);
1521 } catch (ClassCastException cce) {
1522 throw new InternalError("Invalid type in enclosing method information", cce);
1523 }
1524 }
1525
1526 EnclosingMethodInfo(Object[] enclosingInfo) {
1527 validate(enclosingInfo);
1528 this.enclosingClass = (Class<?>)enclosingInfo[0];
1529 this.name = (String)enclosingInfo[1];
1530 this.descriptor = (String)enclosingInfo[2];
1531 }
1532
1533 boolean isPartial() {
1534 return enclosingClass == null || name == null || descriptor == null;
1535 }
1536
1537 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1538
1539 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1540
1541 Class<?> getEnclosingClass() { return enclosingClass; }
1542
1543 String getName() { return name; }
1544
1545 String getDescriptor() { return descriptor; }
1546
1547 }
1548
1549 private static Class<?> toClass(Type o) {
1550 if (o instanceof GenericArrayType gat)
1551 return toClass(gat.getGenericComponentType()).arrayType();
1552 return (Class<?>)o;
1553 }
1554
1555 /**
1556 * If this {@code Class} object represents a local or anonymous
1557 * class within a constructor, returns a {@link
1558 * java.lang.reflect.Constructor Constructor} object representing
1559 * the immediately enclosing constructor of the underlying
1560 * class. Returns {@code null} otherwise. In particular, this
1561 * method returns {@code null} if the underlying class is a local
1562 * or anonymous class immediately enclosed by a class or
1563 * interface declaration, instance initializer or static initializer.
1564 *
1565 * @return the immediately enclosing constructor of the underlying class, if
1566 * that class is a local or anonymous class; otherwise {@code null}.
1567 *
1568 * @since 1.5
1569 */
1570 public Constructor<?> getEnclosingConstructor() {
1571 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1572
1573 if (enclosingInfo == null)
1574 return null;
1575 else {
1576 if (!enclosingInfo.isConstructor())
1577 return null;
1578
1579 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1580 getFactory());
1581 Type [] parameterTypes = typeInfo.getParameterTypes();
1582 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1583
1584 // Convert Types to Classes; returned types *should*
1585 // be class objects since the methodDescriptor's used
1586 // don't have generics information
1587 for (int i = 0; i < parameterClasses.length; i++)
1588 parameterClasses[i] = toClass(parameterTypes[i]);
1589
1590
1591 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1592 Constructor<?>[] candidates = enclosingCandidate
1593 .privateGetDeclaredConstructors(false);
1594 /*
1595 * Loop over all declared constructors; match number
1596 * of and type of parameters.
1597 */
1598 ReflectionFactory fact = getReflectionFactory();
1599 for (Constructor<?> c : candidates) {
1600 if (arrayContentsEq(parameterClasses,
1601 fact.getExecutableSharedParameterTypes(c))) {
1602 return fact.copyConstructor(c);
1603 }
1604 }
1605
1606 throw new InternalError("Enclosing constructor not found");
1607 }
1608 }
1609
1610
1611 /**
1612 * If the class or interface represented by this {@code Class} object
1613 * is a member of another class, returns the {@code Class} object
1614 * representing the class in which it was declared. This method returns
1615 * null if this class or interface is not a member of any other class. If
1616 * this {@code Class} object represents an array class, a primitive
1617 * type, or void, then this method returns null.
1618 *
1619 * @return the declaring class for this class
1620 * @since 1.1
1621 */
1622 public Class<?> getDeclaringClass() {
1623 return getDeclaringClass0();
1624 }
1625
1626 private native Class<?> getDeclaringClass0();
1627
1628
1629 /**
1630 * Returns the immediately enclosing class of the underlying
1631 * class. If the underlying class is a top level class this
1632 * method returns {@code null}.
1633 * @return the immediately enclosing class of the underlying class
1634 * @since 1.5
1635 */
1636 public Class<?> getEnclosingClass() {
1637 // There are five kinds of classes (or interfaces):
1638 // a) Top level classes
1639 // b) Nested classes (static member classes)
1640 // c) Inner classes (non-static member classes)
1641 // d) Local classes (named classes declared within a method)
1642 // e) Anonymous classes
1643
1644
1645 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1646 // attribute if and only if it is a local class or an
1647 // anonymous class.
1648 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1649 Class<?> enclosingCandidate;
1650
1651 if (enclosingInfo == null) {
1652 // This is a top level or a nested class or an inner class (a, b, or c)
1653 enclosingCandidate = getDeclaringClass0();
1654 } else {
1655 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1656 // This is a local class or an anonymous class (d or e)
1657 if (enclosingClass == this || enclosingClass == null)
1658 throw new InternalError("Malformed enclosing method information");
1659 else
1660 enclosingCandidate = enclosingClass;
1661 }
1662 return enclosingCandidate;
1663 }
1664
1665 /**
1666 * Returns the simple name of the underlying class as given in the
1667 * source code. An empty string is returned if the underlying class is
1668 * {@linkplain #isAnonymousClass() anonymous}.
1669 * A {@linkplain #isSynthetic() synthetic class}, one not present
1670 * in source code, can have a non-empty name including special
1671 * characters, such as "{@code $}".
1672 *
1673 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1674 * component type with "[]" appended. In particular the simple
1675 * name of an array class whose component type is anonymous is "[]".
1676 *
1677 * @return the simple name of the underlying class
1678 * @since 1.5
1679 */
1680 public String getSimpleName() {
1681 ReflectionData<T> rd = reflectionData();
1682 String simpleName = rd.simpleName;
1683 if (simpleName == null) {
1684 rd.simpleName = simpleName = getSimpleName0();
1685 }
1686 return simpleName;
1687 }
1688
1689 private String getSimpleName0() {
1690 if (isArray()) {
1691 return getComponentType().getSimpleName().concat("[]");
1692 }
1693 String simpleName = getSimpleBinaryName();
1694 if (simpleName == null) { // top level class
1695 simpleName = getName();
1696 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1697 }
1698 return simpleName;
1699 }
1700
1701 /**
1702 * Return an informative string for the name of this class or interface.
1703 *
1704 * @return an informative string for the name of this class or interface
1705 * @since 1.8
1706 */
1707 public String getTypeName() {
1708 if (isArray()) {
1709 try {
1710 Class<?> cl = this;
1711 int dimensions = 0;
1712 do {
1713 dimensions++;
1714 cl = cl.getComponentType();
1715 } while (cl.isArray());
1716 return cl.getName().concat("[]".repeat(dimensions));
1717 } catch (Throwable e) { /*FALLTHRU*/ }
1718 }
1719 return getName();
1720 }
1721
1722 /**
1723 * Returns the canonical name of the underlying class as
1724 * defined by <cite>The Java Language Specification</cite>.
1725 * Returns {@code null} if the underlying class does not have a canonical
1726 * name. Classes without canonical names include:
1727 * <ul>
1728 * <li>a {@linkplain #isLocalClass() local class}
1729 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1730 * <li>a {@linkplain #isHidden() hidden class}
1731 * <li>an array whose component type does not have a canonical name</li>
1732 * </ul>
1733 *
1734 * The canonical name for a primitive class is the keyword for the
1735 * corresponding primitive type ({@code byte}, {@code short},
1736 * {@code char}, {@code int}, and so on).
1737 *
1738 * <p>An array type has a canonical name if and only if its
1739 * component type has a canonical name. When an array type has a
1740 * canonical name, it is equal to the canonical name of the
1741 * component type followed by "{@code []}".
1742 *
1743 * @return the canonical name of the underlying class if it exists, and
1744 * {@code null} otherwise.
1745 * @jls 6.7 Fully Qualified Names and Canonical Names
1746 * @since 1.5
1747 */
1748 public String getCanonicalName() {
1749 ReflectionData<T> rd = reflectionData();
1750 String canonicalName = rd.canonicalName;
1751 if (canonicalName == null) {
1752 rd.canonicalName = canonicalName = getCanonicalName0();
1753 }
1754 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1755 }
1756
1757 private String getCanonicalName0() {
1758 if (isArray()) {
1759 String canonicalName = getComponentType().getCanonicalName();
1760 if (canonicalName != null)
1761 return canonicalName.concat("[]");
1762 else
1763 return ReflectionData.NULL_SENTINEL;
1764 }
1765 if (isHidden() || isLocalOrAnonymousClass())
1766 return ReflectionData.NULL_SENTINEL;
1767 Class<?> enclosingClass = getEnclosingClass();
1768 if (enclosingClass == null) { // top level class
1769 return getName();
1770 } else {
1771 String enclosingName = enclosingClass.getCanonicalName();
1772 if (enclosingName == null)
1773 return ReflectionData.NULL_SENTINEL;
1774 String simpleName = getSimpleName();
1775 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1776 .append(enclosingName)
1777 .append('.')
1778 .append(simpleName)
1779 .toString();
1780 }
1781 }
1782
1783 /**
1784 * Returns {@code true} if and only if the underlying class
1785 * is an anonymous class.
1786 *
1787 * @apiNote
1788 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1789 *
1790 * @return {@code true} if and only if this class is an anonymous class.
1791 * @since 1.5
1792 * @jls 15.9.5 Anonymous Class Declarations
1793 */
1794 public boolean isAnonymousClass() {
1795 return !isArray() && isLocalOrAnonymousClass() &&
1796 getSimpleBinaryName0() == null;
1797 }
1798
1799 /**
1800 * Returns {@code true} if and only if the underlying class
1801 * is a local class.
1802 *
1803 * @return {@code true} if and only if this class is a local class.
1804 * @since 1.5
1805 * @jls 14.3 Local Class and Interface Declarations
1806 */
1807 public boolean isLocalClass() {
1808 return isLocalOrAnonymousClass() &&
1809 (isArray() || getSimpleBinaryName0() != null);
1810 }
1811
1812 /**
1813 * Returns {@code true} if and only if the underlying class
1814 * is a member class.
1815 *
1816 * @return {@code true} if and only if this class is a member class.
1817 * @since 1.5
1818 * @jls 8.5 Member Class and Interface Declarations
1819 */
1820 public boolean isMemberClass() {
1821 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1822 }
1823
1824 /**
1825 * Returns the "simple binary name" of the underlying class, i.e.,
1826 * the binary name without the leading enclosing class name.
1827 * Returns {@code null} if the underlying class is a top level
1828 * class.
1829 */
1830 private String getSimpleBinaryName() {
1831 if (isTopLevelClass())
1832 return null;
1833 String name = getSimpleBinaryName0();
1834 if (name == null) // anonymous class
1835 return "";
1836 return name;
1837 }
1838
1839 private native String getSimpleBinaryName0();
1840
1841 /**
1842 * Returns {@code true} if this is a top level class. Returns {@code false}
1843 * otherwise.
1844 */
1845 private boolean isTopLevelClass() {
1846 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1847 }
1848
1849 /**
1850 * Returns {@code true} if this is a local class or an anonymous
1851 * class. Returns {@code false} otherwise.
1852 */
1853 private boolean isLocalOrAnonymousClass() {
1854 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1855 // attribute if and only if it is a local class or an
1856 // anonymous class.
1857 return hasEnclosingMethodInfo();
1858 }
1859
1860 private boolean hasEnclosingMethodInfo() {
1861 Object[] enclosingInfo = getEnclosingMethod0();
1862 if (enclosingInfo != null) {
1863 EnclosingMethodInfo.validate(enclosingInfo);
1864 return true;
1865 }
1866 return false;
1867 }
1868
1869 /**
1870 * Returns an array containing {@code Class} objects representing all
1871 * the public classes and interfaces that are members of the class
1872 * represented by this {@code Class} object. This includes public
1873 * class and interface members inherited from superclasses and public class
1874 * and interface members declared by the class. This method returns an
1875 * array of length 0 if this {@code Class} object has no public member
1876 * classes or interfaces. This method also returns an array of length 0 if
1877 * this {@code Class} object represents a primitive type, an array
1878 * class, or void.
1879 *
1880 * @return the array of {@code Class} objects representing the public
1881 * members of this class
1882 * @since 1.1
1883 */
1884 public Class<?>[] getClasses() {
1885 List<Class<?>> list = new ArrayList<>();
1886 Class<?> currentClass = Class.this;
1887 while (currentClass != null) {
1888 for (Class<?> m : currentClass.getDeclaredClasses()) {
1889 if (Modifier.isPublic(m.getModifiers())) {
1890 list.add(m);
1891 }
1892 }
1893 currentClass = currentClass.getSuperclass();
1894 }
1895 return list.toArray(new Class<?>[0]);
1896 }
1897
1898
1899 /**
1900 * Returns an array containing {@code Field} objects reflecting all
1901 * the accessible public fields of the class or interface represented by
1902 * this {@code Class} object.
1903 *
1904 * <p> If this {@code Class} object represents a class or interface with
1905 * no accessible public fields, then this method returns an array of length
1906 * 0.
1907 *
1908 * <p> If this {@code Class} object represents a class, then this method
1909 * returns the public fields of the class and of all its superclasses and
1910 * superinterfaces.
1911 *
1912 * <p> If this {@code Class} object represents an interface, then this
1913 * method returns the fields of the interface and of all its
1914 * superinterfaces.
1915 *
1916 * <p> If this {@code Class} object represents an array type, a primitive
1917 * type, or void, then this method returns an array of length 0.
1918 *
1919 * <p> The elements in the returned array are not sorted and are not in any
1920 * particular order.
1921 *
1922 * @return the array of {@code Field} objects representing the
1923 * public fields
1924 *
1925 * @since 1.1
1926 * @jls 8.2 Class Members
1927 * @jls 8.3 Field Declarations
1928 */
1929 public Field[] getFields() {
1930 return copyFields(privateGetPublicFields());
1931 }
1932
1933
1934 /**
1935 * Returns an array containing {@code Method} objects reflecting all the
1936 * public methods of the class or interface represented by this {@code
1937 * Class} object, including those declared by the class or interface and
1938 * those inherited from superclasses and superinterfaces.
1939 *
1940 * <p> If this {@code Class} object represents an array type, then the
1941 * returned array has a {@code Method} object for each of the public
1942 * methods inherited by the array type from {@code Object}. It does not
1943 * contain a {@code Method} object for {@code clone()}.
1944 *
1945 * <p> If this {@code Class} object represents an interface then the
1946 * returned array does not contain any implicitly declared methods from
1947 * {@code Object}. Therefore, if no methods are explicitly declared in
1948 * this interface or any of its superinterfaces then the returned array
1949 * has length 0. (Note that a {@code Class} object which represents a class
1950 * always has public methods, inherited from {@code Object}.)
1951 *
1952 * <p> The returned array never contains methods with names {@value
1953 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1954 *
1955 * <p> The elements in the returned array are not sorted and are not in any
1956 * particular order.
1957 *
1958 * <p> Generally, the result is computed as with the following 4 step algorithm.
1959 * Let C be the class or interface represented by this {@code Class} object:
1960 * <ol>
1961 * <li> A union of methods is composed of:
1962 * <ol type="a">
1963 * <li> C's declared public instance and static methods as returned by
1964 * {@link #getDeclaredMethods()} and filtered to include only public
1965 * methods.</li>
1966 * <li> If C is a class other than {@code Object}, then include the result
1967 * of invoking this algorithm recursively on the superclass of C.</li>
1968 * <li> Include the results of invoking this algorithm recursively on all
1969 * direct superinterfaces of C, but include only instance methods.</li>
1970 * </ol></li>
1971 * <li> Union from step 1 is partitioned into subsets of methods with same
1972 * signature (name, parameter types) and return type.</li>
1973 * <li> Within each such subset only the most specific methods are selected.
1974 * Let method M be a method from a set of methods with same signature
1975 * and return type. M is most specific if there is no such method
1976 * N != M from the same set, such that N is more specific than M.
1977 * N is more specific than M if:
1978 * <ol type="a">
1979 * <li> N is declared by a class and M is declared by an interface; or</li>
1980 * <li> N and M are both declared by classes or both by interfaces and
1981 * N's declaring type is the same as or a subtype of M's declaring type
1982 * (clearly, if M's and N's declaring types are the same type, then
1983 * M and N are the same method).</li>
1984 * </ol></li>
1985 * <li> The result of this algorithm is the union of all selected methods from
1986 * step 3.</li>
1987 * </ol>
1988 *
1989 * @apiNote There may be more than one method with a particular name
1990 * and parameter types in a class because while the Java language forbids a
1991 * class to declare multiple methods with the same signature but different
1992 * return types, the Java virtual machine does not. This
1993 * increased flexibility in the virtual machine can be used to
1994 * implement various language features. For example, covariant
1995 * returns can be implemented with {@linkplain
1996 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
1997 * method and the overriding method would have the same
1998 * signature but different return types.
1999 *
2000 * @return the array of {@code Method} objects representing the
2001 * public methods of this class
2002 *
2003 * @jls 8.2 Class Members
2004 * @jls 8.4 Method Declarations
2005 * @since 1.1
2006 */
2007 public Method[] getMethods() {
2008 return copyMethods(privateGetPublicMethods());
2009 }
2010
2011
2012 /**
2013 * Returns an array containing {@code Constructor} objects reflecting
2014 * all the public constructors of the class represented by this
2015 * {@code Class} object. An array of length 0 is returned if the
2016 * class has no public constructors, or if the class is an array class, or
2017 * if the class reflects a primitive type or void.
2018 *
2019 * @apiNote
2020 * While this method returns an array of {@code
2021 * Constructor<T>} objects (that is an array of constructors from
2022 * this class), the return type of this method is {@code
2023 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2024 * might be expected. This less informative return type is
2025 * necessary since after being returned from this method, the
2026 * array could be modified to hold {@code Constructor} objects for
2027 * different classes, which would violate the type guarantees of
2028 * {@code Constructor<T>[]}.
2029 *
2030 * @return the array of {@code Constructor} objects representing the
2031 * public constructors of this class
2032 *
2033 * @see #getDeclaredConstructors()
2034 * @since 1.1
2035 */
2036 public Constructor<?>[] getConstructors() {
2037 return copyConstructors(privateGetDeclaredConstructors(true));
2038 }
2039
2040
2041 /**
2042 * Returns a {@code Field} object that reflects the specified public member
2043 * field of the class or interface represented by this {@code Class}
2044 * object. The {@code name} parameter is a {@code String} specifying the
2045 * simple name of the desired field.
2046 *
2047 * <p> The field to be reflected is determined by the algorithm that
2048 * follows. Let C be the class or interface represented by this {@code Class} object:
2049 *
2050 * <OL>
2051 * <LI> If C declares a public field with the name specified, that is the
2052 * field to be reflected.</LI>
2053 * <LI> If no field was found in step 1 above, this algorithm is applied
2054 * recursively to each direct superinterface of C. The direct
2055 * superinterfaces are searched in the order they were declared.</LI>
2056 * <LI> If no field was found in steps 1 and 2 above, and C has a
2057 * superclass S, then this algorithm is invoked recursively upon S.
2058 * If C has no superclass, then a {@code NoSuchFieldException}
2059 * is thrown.</LI>
2060 * </OL>
2061 *
2062 * <p> If this {@code Class} object represents an array type, then this
2063 * method does not find the {@code length} field of the array type.
2064 *
2065 * @param name the field name
2066 * @return the {@code Field} object of this class specified by
2067 * {@code name}
2068 * @throws NoSuchFieldException if a field with the specified name is
2069 * not found.
2070 * @throws NullPointerException if {@code name} is {@code null}
2071 *
2072 * @since 1.1
2073 * @jls 8.2 Class Members
2074 * @jls 8.3 Field Declarations
2075 */
2076 public Field getField(String name) throws NoSuchFieldException {
2077 Objects.requireNonNull(name);
2078 Field field = getField0(name);
2079 if (field == null) {
2080 throw new NoSuchFieldException(name);
2081 }
2082 return getReflectionFactory().copyField(field);
2083 }
2084
2085
2086 /**
2087 * Returns a {@code Method} object that reflects the specified public
2088 * member method of the class or interface represented by this
2089 * {@code Class} object. The {@code name} parameter is a
2090 * {@code String} specifying the simple name of the desired method. The
2091 * {@code parameterTypes} parameter is an array of {@code Class}
2092 * objects that identify the method's formal parameter types, in declared
2093 * order. If {@code parameterTypes} is {@code null}, it is
2094 * treated as if it were an empty array.
2095 *
2096 * <p> If this {@code Class} object represents an array type, then this
2097 * method finds any public method inherited by the array type from
2098 * {@code Object} except method {@code clone()}.
2099 *
2100 * <p> If this {@code Class} object represents an interface then this
2101 * method does not find any implicitly declared method from
2102 * {@code Object}. Therefore, if no methods are explicitly declared in
2103 * this interface or any of its superinterfaces, then this method does not
2104 * find any method.
2105 *
2106 * <p> This method does not find any method with name {@value
2107 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2108 *
2109 * <p> Generally, the method to be reflected is determined by the 4 step
2110 * algorithm that follows.
2111 * Let C be the class or interface represented by this {@code Class} object:
2112 * <ol>
2113 * <li> A union of methods is composed of:
2114 * <ol type="a">
2115 * <li> C's declared public instance and static methods as returned by
2116 * {@link #getDeclaredMethods()} and filtered to include only public
2117 * methods that match given {@code name} and {@code parameterTypes}</li>
2118 * <li> If C is a class other than {@code Object}, then include the result
2119 * of invoking this algorithm recursively on the superclass of C.</li>
2120 * <li> Include the results of invoking this algorithm recursively on all
2121 * direct superinterfaces of C, but include only instance methods.</li>
2122 * </ol></li>
2123 * <li> This union is partitioned into subsets of methods with same
2124 * return type (the selection of methods from step 1 also guarantees that
2125 * they have the same method name and parameter types).</li>
2126 * <li> Within each such subset only the most specific methods are selected.
2127 * Let method M be a method from a set of methods with same VM
2128 * signature (return type, name, parameter types).
2129 * M is most specific if there is no such method N != M from the same
2130 * set, such that N is more specific than M. N is more specific than M
2131 * if:
2132 * <ol type="a">
2133 * <li> N is declared by a class and M is declared by an interface; or</li>
2134 * <li> N and M are both declared by classes or both by interfaces and
2135 * N's declaring type is the same as or a subtype of M's declaring type
2136 * (clearly, if M's and N's declaring types are the same type, then
2137 * M and N are the same method).</li>
2138 * </ol></li>
2139 * <li> The result of this algorithm is chosen arbitrarily from the methods
2140 * with most specific return type among all selected methods from step 3.
2141 * Let R be a return type of a method M from the set of all selected methods
2142 * from step 3. M is a method with most specific return type if there is
2143 * no such method N != M from the same set, having return type S != R,
2144 * such that S is a subtype of R as determined by
2145 * R.class.{@link #isAssignableFrom}(S.class).
2146 * </ol>
2147 *
2148 * @apiNote There may be more than one method with matching name and
2149 * parameter types in a class because while the Java language forbids a
2150 * class to declare multiple methods with the same signature but different
2151 * return types, the Java virtual machine does not. This
2152 * increased flexibility in the virtual machine can be used to
2153 * implement various language features. For example, covariant
2154 * returns can be implemented with {@linkplain
2155 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2156 * method and the overriding method would have the same
2157 * signature but different return types. This method would return the
2158 * overriding method as it would have a more specific return type.
2159 *
2160 * @param name the name of the method
2161 * @param parameterTypes the list of parameters
2162 * @return the {@code Method} object that matches the specified
2163 * {@code name} and {@code parameterTypes}
2164 * @throws NoSuchMethodException if a matching method is not found
2165 * or if the name is {@value ConstantDescs#INIT_NAME} or
2166 * {@value ConstantDescs#CLASS_INIT_NAME}.
2167 * @throws NullPointerException if {@code name} is {@code null}
2168 *
2169 * @jls 8.2 Class Members
2170 * @jls 8.4 Method Declarations
2171 * @since 1.1
2172 */
2173 public Method getMethod(String name, Class<?>... parameterTypes)
2174 throws NoSuchMethodException {
2175 Objects.requireNonNull(name);
2176 Method method = getMethod0(name, parameterTypes);
2177 if (method == null) {
2178 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2179 }
2180 return getReflectionFactory().copyMethod(method);
2181 }
2182
2183 /**
2184 * Returns a {@code Constructor} object that reflects the specified
2185 * public constructor of the class represented by this {@code Class}
2186 * object. The {@code parameterTypes} parameter is an array of
2187 * {@code Class} objects that identify the constructor's formal
2188 * parameter types, in declared order.
2189 *
2190 * If this {@code Class} object represents an inner class
2191 * declared in a non-static context, the formal parameter types
2192 * include the explicit enclosing instance as the first parameter.
2193 *
2194 * <p> The constructor to reflect is the public constructor of the class
2195 * represented by this {@code Class} object whose formal parameter
2196 * types match those specified by {@code parameterTypes}.
2197 *
2198 * @param parameterTypes the parameter array
2199 * @return the {@code Constructor} object of the public constructor that
2200 * matches the specified {@code parameterTypes}
2201 * @throws NoSuchMethodException if a matching constructor is not found,
2202 * including when this {@code Class} object represents
2203 * an interface, a primitive type, an array class, or void.
2204 *
2205 * @see #getDeclaredConstructor(Class[])
2206 * @since 1.1
2207 */
2208 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2209 throws NoSuchMethodException {
2210 return getReflectionFactory().copyConstructor(
2211 getConstructor0(parameterTypes, Member.PUBLIC));
2212 }
2213
2214
2215 /**
2216 * Returns an array of {@code Class} objects reflecting all the
2217 * classes and interfaces declared as members of the class represented by
2218 * this {@code Class} object. This includes public, protected, default
2219 * (package) access, and private classes and interfaces declared by the
2220 * class, but excludes inherited classes and interfaces. This method
2221 * returns an array of length 0 if the class declares no classes or
2222 * interfaces as members, or if this {@code Class} object represents a
2223 * primitive type, an array class, or void.
2224 *
2225 * @return the array of {@code Class} objects representing all the
2226 * declared members of this class
2227 *
2228 * @since 1.1
2229 * @jls 8.5 Member Class and Interface Declarations
2230 */
2231 public Class<?>[] getDeclaredClasses() {
2232 return getDeclaredClasses0();
2233 }
2234
2235
2236 /**
2237 * Returns an array of {@code Field} objects reflecting all the fields
2238 * declared by the class or interface represented by this
2239 * {@code Class} object. This includes public, protected, default
2240 * (package) access, and private fields, but excludes inherited fields.
2241 *
2242 * <p> If this {@code Class} object represents a class or interface with no
2243 * declared fields, then this method returns an array of length 0.
2244 *
2245 * <p> If this {@code Class} object represents an array type, a primitive
2246 * type, or void, then this method returns an array of length 0.
2247 *
2248 * <p> The elements in the returned array are not sorted and are not in any
2249 * particular order.
2250 *
2251 * @return the array of {@code Field} objects representing all the
2252 * declared fields of this class
2253 *
2254 * @since 1.1
2255 * @jls 8.2 Class Members
2256 * @jls 8.3 Field Declarations
2257 */
2258 public Field[] getDeclaredFields() {
2259 return copyFields(privateGetDeclaredFields(false));
2260 }
2261
2262 /**
2263 * Returns an array of {@code RecordComponent} objects representing all the
2264 * record components of this record class, or {@code null} if this class is
2265 * not a record class.
2266 *
2267 * <p> The components are returned in the same order that they are declared
2268 * in the record header. The array is empty if this record class has no
2269 * components. If the class is not a record class, that is {@link
2270 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2271 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2272 * returns a non-null value.
2273 *
2274 * @apiNote
2275 * <p> The following method can be used to find the record canonical constructor:
2276 *
2277 * {@snippet lang="java" :
2278 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2279 * throws NoSuchMethodException {
2280 * Class<?>[] paramTypes =
2281 * Arrays.stream(cls.getRecordComponents())
2282 * .map(RecordComponent::getType)
2283 * .toArray(Class<?>[]::new);
2284 * return cls.getDeclaredConstructor(paramTypes);
2285 * }}
2286 *
2287 * @return An array of {@code RecordComponent} objects representing all the
2288 * record components of this record class, or {@code null} if this
2289 * class is not a record class
2290 *
2291 * @jls 8.10 Record Classes
2292 * @since 16
2293 */
2294 public RecordComponent[] getRecordComponents() {
2295 if (!isRecord()) {
2296 return null;
2297 }
2298 return getRecordComponents0();
2299 }
2300
2301 /**
2302 * Returns an array containing {@code Method} objects reflecting all the
2303 * declared methods of the class or interface represented by this {@code
2304 * Class} object, including public, protected, default (package)
2305 * access, and private methods, but excluding inherited methods.
2306 * The declared methods may include methods <em>not</em> in the
2307 * source of the class or interface, including {@linkplain
2308 * Method#isBridge bridge methods} and other {@linkplain
2309 * Executable#isSynthetic synthetic} methods added by compilers.
2310 *
2311 * <p> If this {@code Class} object represents a class or interface that
2312 * has multiple declared methods with the same name and parameter types,
2313 * but different return types, then the returned array has a {@code Method}
2314 * object for each such method.
2315 *
2316 * <p> If this {@code Class} object represents a class or interface that
2317 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2318 * then the returned array does <em>not</em> have a corresponding {@code
2319 * Method} object.
2320 *
2321 * <p> If this {@code Class} object represents a class or interface with no
2322 * declared methods, then the returned array has length 0.
2323 *
2324 * <p> If this {@code Class} object represents an array type, a primitive
2325 * type, or void, then the returned array has length 0.
2326 *
2327 * <p> The elements in the returned array are not sorted and are not in any
2328 * particular order.
2329 *
2330 * @return the array of {@code Method} objects representing all the
2331 * declared methods of this class
2332 *
2333 * @jls 8.2 Class Members
2334 * @jls 8.4 Method Declarations
2335 * @see <a
2336 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2337 * programming language and JVM modeling in core reflection</a>
2338 * @since 1.1
2339 */
2340 public Method[] getDeclaredMethods() {
2341 return copyMethods(privateGetDeclaredMethods(false));
2342 }
2343
2344 /**
2345 * Returns an array of {@code Constructor} objects reflecting all the
2346 * constructors implicitly or explicitly declared by the class represented by this
2347 * {@code Class} object. These are public, protected, default
2348 * (package) access, and private constructors. The elements in the array
2349 * returned are not sorted and are not in any particular order. If the
2350 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2351 * If a record class has a canonical constructor (JLS {@jls
2352 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2353 *
2354 * This method returns an array of length 0 if this {@code Class}
2355 * object represents an interface, a primitive type, an array class, or
2356 * void.
2357 *
2358 * @return the array of {@code Constructor} objects representing all the
2359 * declared constructors of this class
2360 *
2361 * @since 1.1
2362 * @see #getConstructors()
2363 * @jls 8.8 Constructor Declarations
2364 */
2365 public Constructor<?>[] getDeclaredConstructors() {
2366 return copyConstructors(privateGetDeclaredConstructors(false));
2367 }
2368
2369
2370 /**
2371 * Returns a {@code Field} object that reflects the specified declared
2372 * field of the class or interface represented by this {@code Class}
2373 * object. The {@code name} parameter is a {@code String} that specifies
2374 * the simple name of the desired field.
2375 *
2376 * <p> If this {@code Class} object represents an array type, then this
2377 * method does not find the {@code length} field of the array type.
2378 *
2379 * @param name the name of the field
2380 * @return the {@code Field} object for the specified field in this
2381 * class
2382 * @throws NoSuchFieldException if a field with the specified name is
2383 * not found.
2384 * @throws NullPointerException if {@code name} is {@code null}
2385 *
2386 * @since 1.1
2387 * @jls 8.2 Class Members
2388 * @jls 8.3 Field Declarations
2389 */
2390 public Field getDeclaredField(String name) throws NoSuchFieldException {
2391 Objects.requireNonNull(name);
2392 Field field = searchFields(privateGetDeclaredFields(false), name);
2393 if (field == null) {
2394 throw new NoSuchFieldException(name);
2395 }
2396 return getReflectionFactory().copyField(field);
2397 }
2398
2399
2400 /**
2401 * Returns a {@code Method} object that reflects the specified
2402 * declared method of the class or interface represented by this
2403 * {@code Class} object. The {@code name} parameter is a
2404 * {@code String} that specifies the simple name of the desired
2405 * method, and the {@code parameterTypes} parameter is an array of
2406 * {@code Class} objects that identify the method's formal parameter
2407 * types, in declared order. If more than one method with the same
2408 * parameter types is declared in a class, and one of these methods has a
2409 * return type that is more specific than any of the others, that method is
2410 * returned; otherwise one of the methods is chosen arbitrarily. If the
2411 * name is {@value ConstantDescs#INIT_NAME} or {@value
2412 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2413 * is raised.
2414 *
2415 * <p> If this {@code Class} object represents an array type, then this
2416 * method does not find the {@code clone()} method.
2417 *
2418 * @param name the name of the method
2419 * @param parameterTypes the parameter array
2420 * @return the {@code Method} object for the method of this class
2421 * matching the specified name and parameters
2422 * @throws NoSuchMethodException if a matching method is not found.
2423 * @throws NullPointerException if {@code name} is {@code null}
2424 *
2425 * @jls 8.2 Class Members
2426 * @jls 8.4 Method Declarations
2427 * @since 1.1
2428 */
2429 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2430 throws NoSuchMethodException {
2431 Objects.requireNonNull(name);
2432 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2433 if (method == null) {
2434 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2435 }
2436 return getReflectionFactory().copyMethod(method);
2437 }
2438
2439 /**
2440 * Returns the list of {@code Method} objects for the declared public
2441 * methods of this class or interface that have the specified method name
2442 * and parameter types.
2443 *
2444 * @param name the name of the method
2445 * @param parameterTypes the parameter array
2446 * @return the list of {@code Method} objects for the public methods of
2447 * this class matching the specified name and parameters
2448 */
2449 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2450 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2451 ReflectionFactory factory = getReflectionFactory();
2452 List<Method> result = new ArrayList<>();
2453 for (Method method : methods) {
2454 if (method.getName().equals(name)
2455 && Arrays.equals(
2456 factory.getExecutableSharedParameterTypes(method),
2457 parameterTypes)) {
2458 result.add(factory.copyMethod(method));
2459 }
2460 }
2461 return result;
2462 }
2463
2464 /**
2465 * Returns the most specific {@code Method} object of this class, super class or
2466 * interface that have the specified method name and parameter types.
2467 *
2468 * @param publicOnly true if only public methods are examined, otherwise all methods
2469 * @param name the name of the method
2470 * @param parameterTypes the parameter array
2471 * @return the {@code Method} object for the method found from this class matching
2472 * the specified name and parameters, or null if not found
2473 */
2474 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2475 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2476 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2477 }
2478
2479 /**
2480 * Returns a {@code Constructor} object that reflects the specified
2481 * constructor of the class represented by this
2482 * {@code Class} object. The {@code parameterTypes} parameter is
2483 * an array of {@code Class} objects that identify the constructor's
2484 * formal parameter types, in declared order.
2485 *
2486 * If this {@code Class} object represents an inner class
2487 * declared in a non-static context, the formal parameter types
2488 * include the explicit enclosing instance as the first parameter.
2489 *
2490 * @param parameterTypes the parameter array
2491 * @return The {@code Constructor} object for the constructor with the
2492 * specified parameter list
2493 * @throws NoSuchMethodException if a matching constructor is not found,
2494 * including when this {@code Class} object represents
2495 * an interface, a primitive type, an array class, or void.
2496 *
2497 * @see #getConstructor(Class[])
2498 * @since 1.1
2499 */
2500 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2501 throws NoSuchMethodException {
2502 return getReflectionFactory().copyConstructor(
2503 getConstructor0(parameterTypes, Member.DECLARED));
2504 }
2505
2506 /**
2507 * Finds a resource with a given name.
2508 *
2509 * <p> If this class is in a named {@link Module Module} then this method
2510 * will attempt to find the resource in the module. This is done by
2511 * delegating to the module's class loader {@link
2512 * ClassLoader#findResource(String,String) findResource(String,String)}
2513 * method, invoking it with the module name and the absolute name of the
2514 * resource. Resources in named modules are subject to the rules for
2515 * encapsulation specified in the {@code Module} {@link
2516 * Module#getResourceAsStream getResourceAsStream} method and so this
2517 * method returns {@code null} when the resource is a
2518 * non-"{@code .class}" resource in a package that is not open to the
2519 * caller's module.
2520 *
2521 * <p> Otherwise, if this class is not in a named module then the rules for
2522 * searching resources associated with a given class are implemented by the
2523 * defining {@linkplain ClassLoader class loader} of the class. This method
2524 * delegates to this {@code Class} object's class loader.
2525 * If this {@code Class} object was loaded by the bootstrap class loader,
2526 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2527 *
2528 * <p> Before delegation, an absolute resource name is constructed from the
2529 * given resource name using this algorithm:
2530 *
2531 * <ul>
2532 *
2533 * <li> If the {@code name} begins with a {@code '/'}
2534 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2535 * portion of the {@code name} following the {@code '/'}.
2536 *
2537 * <li> Otherwise, the absolute name is of the following form:
2538 *
2539 * <blockquote>
2540 * {@code modified_package_name/name}
2541 * </blockquote>
2542 *
2543 * <p> Where the {@code modified_package_name} is the package name of this
2544 * object with {@code '/'} substituted for {@code '.'}
2545 * (<code>'\u002e'</code>).
2546 *
2547 * </ul>
2548 *
2549 * @param name name of the desired resource
2550 * @return A {@link java.io.InputStream} object; {@code null} if no
2551 * resource with this name is found, or the resource is in a package
2552 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2553 * least the caller module.
2554 * @throws NullPointerException If {@code name} is {@code null}
2555 *
2556 * @see Module#getResourceAsStream(String)
2557 * @since 1.1
2558 */
2559 @CallerSensitive
2560 public InputStream getResourceAsStream(String name) {
2561 name = resolveName(name);
2562
2563 Module thisModule = getModule();
2564 if (thisModule.isNamed()) {
2565 // check if resource can be located by caller
2566 if (Resources.canEncapsulate(name)
2567 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2568 return null;
2569 }
2570
2571 // resource not encapsulated or in package open to caller
2572 String mn = thisModule.getName();
2573 ClassLoader cl = classLoader;
2574 try {
2575
2576 // special-case built-in class loaders to avoid the
2577 // need for a URL connection
2578 if (cl == null) {
2579 return BootLoader.findResourceAsStream(mn, name);
2580 } else if (cl instanceof BuiltinClassLoader bcl) {
2581 return bcl.findResourceAsStream(mn, name);
2582 } else {
2583 URL url = cl.findResource(mn, name);
2584 return (url != null) ? url.openStream() : null;
2585 }
2586
2587 } catch (IOException | SecurityException e) {
2588 return null;
2589 }
2590 }
2591
2592 // unnamed module
2593 ClassLoader cl = classLoader;
2594 if (cl == null) {
2595 return ClassLoader.getSystemResourceAsStream(name);
2596 } else {
2597 return cl.getResourceAsStream(name);
2598 }
2599 }
2600
2601 /**
2602 * Finds a resource with a given name.
2603 *
2604 * <p> If this class is in a named {@link Module Module} then this method
2605 * will attempt to find the resource in the module. This is done by
2606 * delegating to the module's class loader {@link
2607 * ClassLoader#findResource(String,String) findResource(String,String)}
2608 * method, invoking it with the module name and the absolute name of the
2609 * resource. Resources in named modules are subject to the rules for
2610 * encapsulation specified in the {@code Module} {@link
2611 * Module#getResourceAsStream getResourceAsStream} method and so this
2612 * method returns {@code null} when the resource is a
2613 * non-"{@code .class}" resource in a package that is not open to the
2614 * caller's module.
2615 *
2616 * <p> Otherwise, if this class is not in a named module then the rules for
2617 * searching resources associated with a given class are implemented by the
2618 * defining {@linkplain ClassLoader class loader} of the class. This method
2619 * delegates to this {@code Class} object's class loader.
2620 * If this {@code Class} object was loaded by the bootstrap class loader,
2621 * the method delegates to {@link ClassLoader#getSystemResource}.
2622 *
2623 * <p> Before delegation, an absolute resource name is constructed from the
2624 * given resource name using this algorithm:
2625 *
2626 * <ul>
2627 *
2628 * <li> If the {@code name} begins with a {@code '/'}
2629 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2630 * portion of the {@code name} following the {@code '/'}.
2631 *
2632 * <li> Otherwise, the absolute name is of the following form:
2633 *
2634 * <blockquote>
2635 * {@code modified_package_name/name}
2636 * </blockquote>
2637 *
2638 * <p> Where the {@code modified_package_name} is the package name of this
2639 * object with {@code '/'} substituted for {@code '.'}
2640 * (<code>'\u002e'</code>).
2641 *
2642 * </ul>
2643 *
2644 * @param name name of the desired resource
2645 * @return A {@link java.net.URL} object; {@code null} if no resource with
2646 * this name is found, the resource cannot be located by a URL, or the
2647 * resource is in a package that is not
2648 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2649 * module.
2650 * @throws NullPointerException If {@code name} is {@code null}
2651 * @since 1.1
2652 */
2653 @CallerSensitive
2654 public URL getResource(String name) {
2655 name = resolveName(name);
2656
2657 Module thisModule = getModule();
2658 if (thisModule.isNamed()) {
2659 // check if resource can be located by caller
2660 if (Resources.canEncapsulate(name)
2661 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2662 return null;
2663 }
2664
2665 // resource not encapsulated or in package open to caller
2666 String mn = thisModule.getName();
2667 ClassLoader cl = classLoader;
2668 try {
2669 if (cl == null) {
2670 return BootLoader.findResource(mn, name);
2671 } else {
2672 return cl.findResource(mn, name);
2673 }
2674 } catch (IOException ioe) {
2675 return null;
2676 }
2677 }
2678
2679 // unnamed module
2680 ClassLoader cl = classLoader;
2681 if (cl == null) {
2682 return ClassLoader.getSystemResource(name);
2683 } else {
2684 return cl.getResource(name);
2685 }
2686 }
2687
2688 /**
2689 * Returns true if a resource with the given name can be located by the
2690 * given caller. All resources in a module can be located by code in
2691 * the module. For other callers, then the package needs to be open to
2692 * the caller.
2693 */
2694 private boolean isOpenToCaller(String name, Class<?> caller) {
2695 // assert getModule().isNamed();
2696 Module thisModule = getModule();
2697 Module callerModule = (caller != null) ? caller.getModule() : null;
2698 if (callerModule != thisModule) {
2699 String pn = Resources.toPackageName(name);
2700 if (thisModule.getDescriptor().packages().contains(pn)) {
2701 if (callerModule == null) {
2702 // no caller, return true if the package is open to all modules
2703 return thisModule.isOpen(pn);
2704 }
2705 if (!thisModule.isOpen(pn, callerModule)) {
2706 // package not open to caller
2707 return false;
2708 }
2709 }
2710 }
2711 return true;
2712 }
2713
2714 private transient final ProtectionDomain protectionDomain;
2715
2716 /** Holder for the protection domain returned when the internal domain is null */
2717 private static class Holder {
2718 private static final ProtectionDomain allPermDomain;
2719 static {
2720 Permissions perms = new Permissions();
2721 perms.add(new AllPermission());
2722 allPermDomain = new ProtectionDomain(null, perms);
2723 }
2724 }
2725
2726 /**
2727 * Returns the {@code ProtectionDomain} of this class.
2728 *
2729 * @return the ProtectionDomain of this class
2730 *
2731 * @see java.security.ProtectionDomain
2732 * @since 1.2
2733 */
2734 public ProtectionDomain getProtectionDomain() {
2735 if (protectionDomain == null) {
2736 return Holder.allPermDomain;
2737 } else {
2738 return protectionDomain;
2739 }
2740 }
2741
2742 /*
2743 * Returns the Class object for the named primitive type. Type parameter T
2744 * avoids redundant casts for trusted code.
2745 */
2746 static native <T> Class<T> getPrimitiveClass(String name);
2747
2748 /**
2749 * Add a package name prefix if the name is not absolute. Remove leading "/"
2750 * if name is absolute
2751 */
2752 private String resolveName(String name) {
2753 if (!name.startsWith("/")) {
2754 String baseName = getPackageName();
2755 if (!baseName.isEmpty()) {
2756 int len = baseName.length() + 1 + name.length();
2757 StringBuilder sb = new StringBuilder(len);
2758 name = sb.append(baseName.replace('.', '/'))
2759 .append('/')
2760 .append(name)
2761 .toString();
2762 }
2763 } else {
2764 name = name.substring(1);
2765 }
2766 return name;
2767 }
2768
2769 /**
2770 * Atomic operations support.
2771 */
2772 private static class Atomic {
2773 // initialize Unsafe machinery here, since we need to call Class.class instance method
2774 // and have to avoid calling it in the static initializer of the Class class...
2775 private static final Unsafe unsafe = Unsafe.getUnsafe();
2776 // offset of Class.reflectionData instance field
2777 private static final long reflectionDataOffset
2778 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2779 // offset of Class.annotationType instance field
2780 private static final long annotationTypeOffset
2781 = unsafe.objectFieldOffset(Class.class, "annotationType");
2782 // offset of Class.annotationData instance field
2783 private static final long annotationDataOffset
2784 = unsafe.objectFieldOffset(Class.class, "annotationData");
2785
2786 static <T> boolean casReflectionData(Class<?> clazz,
2787 SoftReference<ReflectionData<T>> oldData,
2788 SoftReference<ReflectionData<T>> newData) {
2789 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2790 }
2791
2792 static boolean casAnnotationType(Class<?> clazz,
2793 AnnotationType oldType,
2794 AnnotationType newType) {
2795 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2796 }
2797
2798 static boolean casAnnotationData(Class<?> clazz,
2799 AnnotationData oldData,
2800 AnnotationData newData) {
2801 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2802 }
2803 }
2804
2805 /**
2806 * Reflection support.
2807 */
2808
2809 // Reflection data caches various derived names and reflective members. Cached
2810 // values may be invalidated when JVM TI RedefineClasses() is called
2811 private static class ReflectionData<T> {
2812 volatile Field[] declaredFields;
2813 volatile Field[] publicFields;
2814 volatile Method[] declaredMethods;
2815 volatile Method[] publicMethods;
2816 volatile Constructor<T>[] declaredConstructors;
2817 volatile Constructor<T>[] publicConstructors;
2818 // Intermediate results for getFields and getMethods
2819 volatile Field[] declaredPublicFields;
2820 volatile Method[] declaredPublicMethods;
2821 volatile Class<?>[] interfaces;
2822
2823 // Cached names
2824 String simpleName;
2825 String canonicalName;
2826 static final String NULL_SENTINEL = new String();
2827
2828 // Value of classRedefinedCount when we created this ReflectionData instance
2829 final int redefinedCount;
2830
2831 ReflectionData(int redefinedCount) {
2832 this.redefinedCount = redefinedCount;
2833 }
2834 }
2835
2836 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2837
2838 // Incremented by the VM on each call to JVM TI RedefineClasses()
2839 // that redefines this class or a superclass.
2840 private transient volatile int classRedefinedCount;
2841
2842 // Lazily create and cache ReflectionData
2843 private ReflectionData<T> reflectionData() {
2844 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2845 int classRedefinedCount = this.classRedefinedCount;
2846 ReflectionData<T> rd;
2847 if (reflectionData != null &&
2848 (rd = reflectionData.get()) != null &&
2849 rd.redefinedCount == classRedefinedCount) {
2850 return rd;
2851 }
2852 // else no SoftReference or cleared SoftReference or stale ReflectionData
2853 // -> create and replace new instance
2854 return newReflectionData(reflectionData, classRedefinedCount);
2855 }
2856
2857 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2858 int classRedefinedCount) {
2859 while (true) {
2860 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2861 // try to CAS it...
2862 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
2863 return rd;
2864 }
2865 // else retry
2866 oldReflectionData = this.reflectionData;
2867 classRedefinedCount = this.classRedefinedCount;
2868 if (oldReflectionData != null &&
2869 (rd = oldReflectionData.get()) != null &&
2870 rd.redefinedCount == classRedefinedCount) {
2871 return rd;
2872 }
2873 }
2874 }
2875
2876 // Generic signature handling
2877 private native String getGenericSignature0();
2878
2879 // Generic info repository; lazily initialized
2880 private transient volatile ClassRepository genericInfo;
2881
2882 // accessor for factory
2883 private GenericsFactory getFactory() {
2884 // create scope and factory
2885 return CoreReflectionFactory.make(this, ClassScope.make(this));
2886 }
2887
2888 // accessor for generic info repository;
2889 // generic info is lazily initialized
2890 private ClassRepository getGenericInfo() {
2891 ClassRepository genericInfo = this.genericInfo;
2892 if (genericInfo == null) {
2893 String signature = getGenericSignature0();
2894 if (signature == null) {
2895 genericInfo = ClassRepository.NONE;
2896 } else {
2897 genericInfo = ClassRepository.make(signature, getFactory());
2898 }
2899 this.genericInfo = genericInfo;
2900 }
2901 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2902 }
2903
2904 // Annotations handling
2905 native byte[] getRawAnnotations();
2906 // Since 1.8
2907 native byte[] getRawTypeAnnotations();
2908 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2909 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2910 }
2911
2912 native ConstantPool getConstantPool();
2913
2914 //
2915 //
2916 // java.lang.reflect.Field handling
2917 //
2918 //
2919
2920 // Returns an array of "root" fields. These Field objects must NOT
2921 // be propagated to the outside world, but must instead be copied
2922 // via ReflectionFactory.copyField.
2923 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2924 Field[] res;
2925 ReflectionData<T> rd = reflectionData();
2926 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2927 if (res != null) return res;
2928 // No cached value available; request value from VM
2929 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2930 if (publicOnly) {
2931 rd.declaredPublicFields = res;
2932 } else {
2933 rd.declaredFields = res;
2934 }
2935 return res;
2936 }
2937
2938 // Returns an array of "root" fields. These Field objects must NOT
2939 // be propagated to the outside world, but must instead be copied
2940 // via ReflectionFactory.copyField.
2941 private Field[] privateGetPublicFields() {
2942 Field[] res;
2943 ReflectionData<T> rd = reflectionData();
2944 res = rd.publicFields;
2945 if (res != null) return res;
2946
2947 // Use a linked hash set to ensure order is preserved and
2948 // fields from common super interfaces are not duplicated
2949 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2950
2951 // Local fields
2952 addAll(fields, privateGetDeclaredFields(true));
2953
2954 // Direct superinterfaces, recursively
2955 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2956 addAll(fields, si.privateGetPublicFields());
2957 }
2958
2959 // Direct superclass, recursively
2960 Class<?> sc = getSuperclass();
2961 if (sc != null) {
2962 addAll(fields, sc.privateGetPublicFields());
2963 }
2964
2965 res = fields.toArray(new Field[0]);
2966 rd.publicFields = res;
2967 return res;
2968 }
2969
2970 private static void addAll(Collection<Field> c, Field[] o) {
2971 for (Field f : o) {
2972 c.add(f);
2973 }
2974 }
2975
2976
2977 //
2978 //
2979 // java.lang.reflect.Constructor handling
2980 //
2981 //
2982
2983 // Returns an array of "root" constructors. These Constructor
2984 // objects must NOT be propagated to the outside world, but must
2985 // instead be copied via ReflectionFactory.copyConstructor.
2986 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
2987 Constructor<T>[] res;
2988 ReflectionData<T> rd = reflectionData();
2989 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
2990 if (res != null) return res;
2991 // No cached value available; request value from VM
2992 if (isInterface()) {
2993 @SuppressWarnings("unchecked")
2994 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
2995 res = temporaryRes;
2996 } else {
2997 res = getDeclaredConstructors0(publicOnly);
2998 }
2999 if (publicOnly) {
3000 rd.publicConstructors = res;
3001 } else {
3002 rd.declaredConstructors = res;
3003 }
3004 return res;
3005 }
3006
3007 //
3008 //
3009 // java.lang.reflect.Method handling
3010 //
3011 //
3012
3013 // Returns an array of "root" methods. These Method objects must NOT
3014 // be propagated to the outside world, but must instead be copied
3015 // via ReflectionFactory.copyMethod.
3016 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3017 Method[] res;
3018 ReflectionData<T> rd = reflectionData();
3019 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3020 if (res != null) return res;
3021 // No cached value available; request value from VM
3022 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3023 if (publicOnly) {
3024 rd.declaredPublicMethods = res;
3025 } else {
3026 rd.declaredMethods = res;
3027 }
3028 return res;
3029 }
3030
3031 // Returns an array of "root" methods. These Method objects must NOT
3032 // be propagated to the outside world, but must instead be copied
3033 // via ReflectionFactory.copyMethod.
3034 private Method[] privateGetPublicMethods() {
3035 Method[] res;
3036 ReflectionData<T> rd = reflectionData();
3037 res = rd.publicMethods;
3038 if (res != null) return res;
3039
3040 // No cached value available; compute value recursively.
3041 // Start by fetching public declared methods...
3042 PublicMethods pms = new PublicMethods();
3043 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3044 pms.merge(m);
3045 }
3046 // ...then recur over superclass methods...
3047 Class<?> sc = getSuperclass();
3048 if (sc != null) {
3049 for (Method m : sc.privateGetPublicMethods()) {
3050 pms.merge(m);
3051 }
3052 }
3053 // ...and finally over direct superinterfaces.
3054 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3055 for (Method m : intf.privateGetPublicMethods()) {
3056 // static interface methods are not inherited
3057 if (!Modifier.isStatic(m.getModifiers())) {
3058 pms.merge(m);
3059 }
3060 }
3061 }
3062
3063 res = pms.toArray();
3064 rd.publicMethods = res;
3065 return res;
3066 }
3067
3068
3069 //
3070 // Helpers for fetchers of one field, method, or constructor
3071 //
3072
3073 // This method does not copy the returned Field object!
3074 private static Field searchFields(Field[] fields, String name) {
3075 for (Field field : fields) {
3076 if (field.getName().equals(name)) {
3077 return field;
3078 }
3079 }
3080 return null;
3081 }
3082
3083 // Returns a "root" Field object. This Field object must NOT
3084 // be propagated to the outside world, but must instead be copied
3085 // via ReflectionFactory.copyField.
3086 private Field getField0(String name) {
3087 // Note: the intent is that the search algorithm this routine
3088 // uses be equivalent to the ordering imposed by
3089 // privateGetPublicFields(). It fetches only the declared
3090 // public fields for each class, however, to reduce the number
3091 // of Field objects which have to be created for the common
3092 // case where the field being requested is declared in the
3093 // class which is being queried.
3094 Field res;
3095 // Search declared public fields
3096 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3097 return res;
3098 }
3099 // Direct superinterfaces, recursively
3100 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3101 for (Class<?> c : interfaces) {
3102 if ((res = c.getField0(name)) != null) {
3103 return res;
3104 }
3105 }
3106 // Direct superclass, recursively
3107 if (!isInterface()) {
3108 Class<?> c = getSuperclass();
3109 if (c != null) {
3110 if ((res = c.getField0(name)) != null) {
3111 return res;
3112 }
3113 }
3114 }
3115 return null;
3116 }
3117
3118 // This method does not copy the returned Method object!
3119 private static Method searchMethods(Method[] methods,
3120 String name,
3121 Class<?>[] parameterTypes)
3122 {
3123 ReflectionFactory fact = getReflectionFactory();
3124 Method res = null;
3125 for (Method m : methods) {
3126 if (m.getName().equals(name)
3127 && arrayContentsEq(parameterTypes,
3128 fact.getExecutableSharedParameterTypes(m))
3129 && (res == null
3130 || (res.getReturnType() != m.getReturnType()
3131 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3132 res = m;
3133 }
3134 return res;
3135 }
3136
3137 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3138
3139 // Returns a "root" Method object. This Method object must NOT
3140 // be propagated to the outside world, but must instead be copied
3141 // via ReflectionFactory.copyMethod.
3142 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3143 PublicMethods.MethodList res = getMethodsRecursive(
3144 name,
3145 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3146 /* includeStatic */ true, /* publicOnly */ true);
3147 return res == null ? null : res.getMostSpecific();
3148 }
3149
3150 // Returns a list of "root" Method objects. These Method objects must NOT
3151 // be propagated to the outside world, but must instead be copied
3152 // via ReflectionFactory.copyMethod.
3153 private PublicMethods.MethodList getMethodsRecursive(String name,
3154 Class<?>[] parameterTypes,
3155 boolean includeStatic,
3156 boolean publicOnly) {
3157 // 1st check declared methods
3158 Method[] methods = privateGetDeclaredMethods(publicOnly);
3159 PublicMethods.MethodList res = PublicMethods.MethodList
3160 .filter(methods, name, parameterTypes, includeStatic);
3161 // if there is at least one match among declared methods, we need not
3162 // search any further as such match surely overrides matching methods
3163 // declared in superclass(es) or interface(s).
3164 if (res != null) {
3165 return res;
3166 }
3167
3168 // if there was no match among declared methods,
3169 // we must consult the superclass (if any) recursively...
3170 Class<?> sc = getSuperclass();
3171 if (sc != null) {
3172 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3173 }
3174
3175 // ...and coalesce the superclass methods with methods obtained
3176 // from directly implemented interfaces excluding static methods...
3177 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3178 res = PublicMethods.MethodList.merge(
3179 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3180 }
3181
3182 return res;
3183 }
3184
3185 // Returns a "root" Constructor object. This Constructor object must NOT
3186 // be propagated to the outside world, but must instead be copied
3187 // via ReflectionFactory.copyConstructor.
3188 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3189 int which) throws NoSuchMethodException
3190 {
3191 ReflectionFactory fact = getReflectionFactory();
3192 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3193 for (Constructor<T> constructor : constructors) {
3194 if (arrayContentsEq(parameterTypes,
3195 fact.getExecutableSharedParameterTypes(constructor))) {
3196 return constructor;
3197 }
3198 }
3199 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3200 }
3201
3202 //
3203 // Other helpers and base implementation
3204 //
3205
3206 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3207 if (a1 == null) {
3208 return a2 == null || a2.length == 0;
3209 }
3210
3211 if (a2 == null) {
3212 return a1.length == 0;
3213 }
3214
3215 if (a1.length != a2.length) {
3216 return false;
3217 }
3218
3219 for (int i = 0; i < a1.length; i++) {
3220 if (a1[i] != a2[i]) {
3221 return false;
3222 }
3223 }
3224
3225 return true;
3226 }
3227
3228 private static Field[] copyFields(Field[] arg) {
3229 Field[] out = new Field[arg.length];
3230 ReflectionFactory fact = getReflectionFactory();
3231 for (int i = 0; i < arg.length; i++) {
3232 out[i] = fact.copyField(arg[i]);
3233 }
3234 return out;
3235 }
3236
3237 private static Method[] copyMethods(Method[] arg) {
3238 Method[] out = new Method[arg.length];
3239 ReflectionFactory fact = getReflectionFactory();
3240 for (int i = 0; i < arg.length; i++) {
3241 out[i] = fact.copyMethod(arg[i]);
3242 }
3243 return out;
3244 }
3245
3246 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3247 Constructor<U>[] out = arg.clone();
3248 ReflectionFactory fact = getReflectionFactory();
3249 for (int i = 0; i < out.length; i++) {
3250 out[i] = fact.copyConstructor(out[i]);
3251 }
3252 return out;
3253 }
3254
3255 private native Field[] getDeclaredFields0(boolean publicOnly);
3256 private native Method[] getDeclaredMethods0(boolean publicOnly);
3257 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3258 private native Class<?>[] getDeclaredClasses0();
3259
3260 /*
3261 * Returns an array containing the components of the Record attribute,
3262 * or null if the attribute is not present.
3263 *
3264 * Note that this method returns non-null array on a class with
3265 * the Record attribute even if this class is not a record.
3266 */
3267 private native RecordComponent[] getRecordComponents0();
3268 private native boolean isRecord0();
3269
3270 /**
3271 * Helper method to get the method name from arguments.
3272 */
3273 private String methodToString(String name, Class<?>[] argTypes) {
3274 return getName() + '.' + name +
3275 ((argTypes == null || argTypes.length == 0) ?
3276 "()" :
3277 Arrays.stream(argTypes)
3278 .map(c -> c == null ? "null" : c.getName())
3279 .collect(Collectors.joining(",", "(", ")")));
3280 }
3281
3282 /** use serialVersionUID from JDK 1.1 for interoperability */
3283 @java.io.Serial
3284 private static final long serialVersionUID = 3206093459760846163L;
3285
3286
3287 /**
3288 * Class Class is special cased within the Serialization Stream Protocol.
3289 *
3290 * A Class instance is written initially into an ObjectOutputStream in the
3291 * following format:
3292 * <pre>
3293 * {@code TC_CLASS} ClassDescriptor
3294 * A ClassDescriptor is a special cased serialization of
3295 * a {@code java.io.ObjectStreamClass} instance.
3296 * </pre>
3297 * A new handle is generated for the initial time the class descriptor
3298 * is written into the stream. Future references to the class descriptor
3299 * are written as references to the initial class descriptor instance.
3300 *
3301 * @see java.io.ObjectStreamClass
3302 */
3303 @java.io.Serial
3304 private static final ObjectStreamField[] serialPersistentFields =
3305 new ObjectStreamField[0];
3306
3307
3308 /**
3309 * Returns the assertion status that would be assigned to this
3310 * class if it were to be initialized at the time this method is invoked.
3311 * If this class has had its assertion status set, the most recent
3312 * setting will be returned; otherwise, if any package default assertion
3313 * status pertains to this class, the most recent setting for the most
3314 * specific pertinent package default assertion status is returned;
3315 * otherwise, if this class is not a system class (i.e., it has a
3316 * class loader) its class loader's default assertion status is returned;
3317 * otherwise, the system class default assertion status is returned.
3318 *
3319 * @apiNote
3320 * Few programmers will have any need for this method; it is provided
3321 * for the benefit of the JDK itself. (It allows a class to determine at
3322 * the time that it is initialized whether assertions should be enabled.)
3323 * Note that this method is not guaranteed to return the actual
3324 * assertion status that was (or will be) associated with the specified
3325 * class when it was (or will be) initialized.
3326 *
3327 * @return the desired assertion status of the specified class.
3328 * @see java.lang.ClassLoader#setClassAssertionStatus
3329 * @see java.lang.ClassLoader#setPackageAssertionStatus
3330 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3331 * @since 1.4
3332 */
3333 public boolean desiredAssertionStatus() {
3334 ClassLoader loader = classLoader;
3335 // If the loader is null this is a system class, so ask the VM
3336 if (loader == null)
3337 return desiredAssertionStatus0(this);
3338
3339 // If the classloader has been initialized with the assertion
3340 // directives, ask it. Otherwise, ask the VM.
3341 synchronized(loader.assertionLock) {
3342 if (loader.classAssertionStatus != null) {
3343 return loader.desiredAssertionStatus(getName());
3344 }
3345 }
3346 return desiredAssertionStatus0(this);
3347 }
3348
3349 // Retrieves the desired assertion status of this class from the VM
3350 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3351
3352 /**
3353 * Returns true if and only if this class was declared as an enum in the
3354 * source code.
3355 *
3356 * Note that {@link java.lang.Enum} is not itself an enum class.
3357 *
3358 * Also note that if an enum constant is declared with a class body,
3359 * the class of that enum constant object is an anonymous class
3360 * and <em>not</em> the class of the declaring enum class. The
3361 * {@link Enum#getDeclaringClass} method of an enum constant can
3362 * be used to get the class of the enum class declaring the
3363 * constant.
3364 *
3365 * @return true if and only if this class was declared as an enum in the
3366 * source code
3367 * @since 1.5
3368 * @jls 8.9.1 Enum Constants
3369 */
3370 public boolean isEnum() {
3371 // An enum must both directly extend java.lang.Enum and have
3372 // the ENUM bit set; classes for specialized enum constants
3373 // don't do the former.
3374 return (this.getModifiers() & ENUM) != 0 &&
3375 this.getSuperclass() == java.lang.Enum.class;
3376 }
3377
3378 /**
3379 * Returns {@code true} if and only if this class is a record class.
3380 *
3381 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3382 * class is {@code java.lang.Record}. A record class is {@linkplain
3383 * Modifier#FINAL final}. A record class has (possibly zero) record
3384 * components; {@link #getRecordComponents()} returns a non-null but
3385 * possibly empty value for a record.
3386 *
3387 * <p> Note that class {@link Record} is not a record class and thus
3388 * invoking this method on class {@code Record} returns {@code false}.
3389 *
3390 * @return true if and only if this class is a record class, otherwise false
3391 * @jls 8.10 Record Classes
3392 * @since 16
3393 */
3394 public boolean isRecord() {
3395 // this superclass and final modifier check is not strictly necessary
3396 // they are intrinsified and serve as a fast-path check
3397 return getSuperclass() == java.lang.Record.class &&
3398 (this.getModifiers() & Modifier.FINAL) != 0 &&
3399 isRecord0();
3400 }
3401
3402 // Fetches the factory for reflective objects
3403 private static ReflectionFactory getReflectionFactory() {
3404 var factory = reflectionFactory;
3405 if (factory != null) {
3406 return factory;
3407 }
3408 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3409 }
3410 private static ReflectionFactory reflectionFactory;
3411
3412 /**
3413 * When CDS is enabled, the Class class may be aot-initialized. However,
3414 * we can't archive reflectionFactory, so we reset it to null, so it
3415 * will be allocated again at runtime.
3416 */
3417 private static void resetArchivedStates() {
3418 reflectionFactory = null;
3419 }
3420
3421 /**
3422 * Returns the elements of this enum class or null if this
3423 * Class object does not represent an enum class.
3424 *
3425 * @return an array containing the values comprising the enum class
3426 * represented by this {@code Class} object in the order they're
3427 * declared, or null if this {@code Class} object does not
3428 * represent an enum class
3429 * @since 1.5
3430 * @jls 8.9.1 Enum Constants
3431 */
3432 public T[] getEnumConstants() {
3433 T[] values = getEnumConstantsShared();
3434 return (values != null) ? values.clone() : null;
3435 }
3436
3437 /**
3438 * Returns the elements of this enum class or null if this
3439 * Class object does not represent an enum class;
3440 * identical to getEnumConstants except that the result is
3441 * uncloned, cached, and shared by all callers.
3442 */
3443 T[] getEnumConstantsShared() {
3444 T[] constants = enumConstants;
3445 if (constants == null) {
3446 if (!isEnum()) return null;
3447 try {
3448 final Method values = getMethod("values");
3449 values.setAccessible(true);
3450 @SuppressWarnings("unchecked")
3451 T[] temporaryConstants = (T[])values.invoke(null);
3452 enumConstants = constants = temporaryConstants;
3453 }
3454 // These can happen when users concoct enum-like classes
3455 // that don't comply with the enum spec.
3456 catch (InvocationTargetException | NoSuchMethodException |
3457 IllegalAccessException | NullPointerException |
3458 ClassCastException ex) { return null; }
3459 }
3460 return constants;
3461 }
3462 private transient volatile T[] enumConstants;
3463
3464 /**
3465 * Returns a map from simple name to enum constant. This package-private
3466 * method is used internally by Enum to implement
3467 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3468 * efficiently. Note that the map is returned by this method is
3469 * created lazily on first use. Typically it won't ever get created.
3470 */
3471 Map<String, T> enumConstantDirectory() {
3472 Map<String, T> directory = enumConstantDirectory;
3473 if (directory == null) {
3474 T[] universe = getEnumConstantsShared();
3475 if (universe == null)
3476 throw new IllegalArgumentException(
3477 getName() + " is not an enum class");
3478 directory = HashMap.newHashMap(universe.length);
3479 for (T constant : universe) {
3480 directory.put(((Enum<?>)constant).name(), constant);
3481 }
3482 enumConstantDirectory = directory;
3483 }
3484 return directory;
3485 }
3486 private transient volatile Map<String, T> enumConstantDirectory;
3487
3488 /**
3489 * Casts an object to the class or interface represented
3490 * by this {@code Class} object.
3491 *
3492 * @param obj the object to be cast
3493 * @return the object after casting, or null if obj is null
3494 *
3495 * @throws ClassCastException if the object is not
3496 * null and is not assignable to the type T.
3497 *
3498 * @since 1.5
3499 */
3500 @SuppressWarnings("unchecked")
3501 @IntrinsicCandidate
3502 public T cast(Object obj) {
3503 if (obj != null && !isInstance(obj))
3504 throw new ClassCastException(cannotCastMsg(obj));
3505 return (T) obj;
3506 }
3507
3508 private String cannotCastMsg(Object obj) {
3509 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3510 }
3511
3512 /**
3513 * Casts this {@code Class} object to represent a subclass of the class
3514 * represented by the specified class object. Checks that the cast
3515 * is valid, and throws a {@code ClassCastException} if it is not. If
3516 * this method succeeds, it always returns a reference to this {@code Class} object.
3517 *
3518 * <p>This method is useful when a client needs to "narrow" the type of
3519 * a {@code Class} object to pass it to an API that restricts the
3520 * {@code Class} objects that it is willing to accept. A cast would
3521 * generate a compile-time warning, as the correctness of the cast
3522 * could not be checked at runtime (because generic types are implemented
3523 * by erasure).
3524 *
3525 * @param <U> the type to cast this {@code Class} object to
3526 * @param clazz the class of the type to cast this {@code Class} object to
3527 * @return this {@code Class} object, cast to represent a subclass of
3528 * the specified class object.
3529 * @throws ClassCastException if this {@code Class} object does not
3530 * represent a subclass of the specified class (here "subclass" includes
3531 * the class itself).
3532 * @since 1.5
3533 */
3534 @SuppressWarnings("unchecked")
3535 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3536 if (clazz.isAssignableFrom(this))
3537 return (Class<? extends U>) this;
3538 else
3539 throw new ClassCastException(this.toString());
3540 }
3541
3542 /**
3543 * {@inheritDoc}
3544 * <p>Note that any annotation returned by this method is a
3545 * declaration annotation.
3546 *
3547 * @throws NullPointerException {@inheritDoc}
3548 * @since 1.5
3549 */
3550 @Override
3551 @SuppressWarnings("unchecked")
3552 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3553 Objects.requireNonNull(annotationClass);
3554
3555 return (A) annotationData().annotations.get(annotationClass);
3556 }
3557
3558 /**
3559 * {@inheritDoc}
3560 * @throws NullPointerException {@inheritDoc}
3561 * @since 1.5
3562 */
3563 @Override
3564 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3565 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3566 }
3567
3568 /**
3569 * {@inheritDoc}
3570 * <p>Note that any annotations returned by this method are
3571 * declaration annotations.
3572 *
3573 * @throws NullPointerException {@inheritDoc}
3574 * @since 1.8
3575 */
3576 @Override
3577 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3578 Objects.requireNonNull(annotationClass);
3579
3580 AnnotationData annotationData = annotationData();
3581 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3582 this,
3583 annotationClass);
3584 }
3585
3586 /**
3587 * {@inheritDoc}
3588 * <p>Note that any annotations returned by this method are
3589 * declaration annotations.
3590 *
3591 * @since 1.5
3592 */
3593 @Override
3594 public Annotation[] getAnnotations() {
3595 return AnnotationParser.toArray(annotationData().annotations);
3596 }
3597
3598 /**
3599 * {@inheritDoc}
3600 * <p>Note that any annotation returned by this method is a
3601 * declaration annotation.
3602 *
3603 * @throws NullPointerException {@inheritDoc}
3604 * @since 1.8
3605 */
3606 @Override
3607 @SuppressWarnings("unchecked")
3608 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3609 Objects.requireNonNull(annotationClass);
3610
3611 return (A) annotationData().declaredAnnotations.get(annotationClass);
3612 }
3613
3614 /**
3615 * {@inheritDoc}
3616 * <p>Note that any annotations returned by this method are
3617 * declaration annotations.
3618 *
3619 * @throws NullPointerException {@inheritDoc}
3620 * @since 1.8
3621 */
3622 @Override
3623 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3624 Objects.requireNonNull(annotationClass);
3625
3626 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3627 annotationClass);
3628 }
3629
3630 /**
3631 * {@inheritDoc}
3632 * <p>Note that any annotations returned by this method are
3633 * declaration annotations.
3634 *
3635 * @since 1.5
3636 */
3637 @Override
3638 public Annotation[] getDeclaredAnnotations() {
3639 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3640 }
3641
3642 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3643 private static class AnnotationData {
3644 final Map<Class<? extends Annotation>, Annotation> annotations;
3645 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3646
3647 // Value of classRedefinedCount when we created this AnnotationData instance
3648 final int redefinedCount;
3649
3650 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3651 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3652 int redefinedCount) {
3653 this.annotations = annotations;
3654 this.declaredAnnotations = declaredAnnotations;
3655 this.redefinedCount = redefinedCount;
3656 }
3657 }
3658
3659 // Annotations cache
3660 @SuppressWarnings("UnusedDeclaration")
3661 private transient volatile AnnotationData annotationData;
3662
3663 private AnnotationData annotationData() {
3664 while (true) { // retry loop
3665 AnnotationData annotationData = this.annotationData;
3666 int classRedefinedCount = this.classRedefinedCount;
3667 if (annotationData != null &&
3668 annotationData.redefinedCount == classRedefinedCount) {
3669 return annotationData;
3670 }
3671 // null or stale annotationData -> optimistically create new instance
3672 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3673 // try to install it
3674 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3675 // successfully installed new AnnotationData
3676 return newAnnotationData;
3677 }
3678 }
3679 }
3680
3681 private AnnotationData createAnnotationData(int classRedefinedCount) {
3682 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3683 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3684 Class<?> superClass = getSuperclass();
3685 Map<Class<? extends Annotation>, Annotation> annotations = null;
3686 if (superClass != null) {
3687 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3688 superClass.annotationData().annotations;
3689 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3690 Class<? extends Annotation> annotationClass = e.getKey();
3691 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3692 if (annotations == null) { // lazy construction
3693 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3694 declaredAnnotations.size(),
3695 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3696 )
3697 );
3698 }
3699 annotations.put(annotationClass, e.getValue());
3700 }
3701 }
3702 }
3703 if (annotations == null) {
3704 // no inherited annotations -> share the Map with declaredAnnotations
3705 annotations = declaredAnnotations;
3706 } else {
3707 // at least one inherited annotation -> declared may override inherited
3708 annotations.putAll(declaredAnnotations);
3709 }
3710 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3711 }
3712
3713 // Annotation interfaces cache their internal (AnnotationType) form
3714
3715 @SuppressWarnings("UnusedDeclaration")
3716 private transient volatile AnnotationType annotationType;
3717
3718 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3719 return Atomic.casAnnotationType(this, oldType, newType);
3720 }
3721
3722 AnnotationType getAnnotationType() {
3723 return annotationType;
3724 }
3725
3726 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3727 return annotationData().declaredAnnotations;
3728 }
3729
3730 /* Backing store of user-defined values pertaining to this class.
3731 * Maintained by the ClassValue class.
3732 */
3733 transient ClassValue.ClassValueMap classValueMap;
3734
3735 /**
3736 * Returns an {@code AnnotatedType} object that represents the use of a
3737 * type to specify the superclass of the entity represented by this {@code
3738 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3739 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3740 * Foo.)
3741 *
3742 * <p> If this {@code Class} object represents a class whose declaration
3743 * does not explicitly indicate an annotated superclass, then the return
3744 * value is an {@code AnnotatedType} object representing an element with no
3745 * annotations.
3746 *
3747 * <p> If this {@code Class} represents either the {@code Object} class, an
3748 * interface type, an array type, a primitive type, or void, the return
3749 * value is {@code null}.
3750 *
3751 * @return an object representing the superclass
3752 * @since 1.8
3753 */
3754 public AnnotatedType getAnnotatedSuperclass() {
3755 if (this == Object.class ||
3756 isInterface() ||
3757 isArray() ||
3758 isPrimitive() ||
3759 this == Void.TYPE) {
3760 return null;
3761 }
3762
3763 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3764 }
3765
3766 /**
3767 * Returns an array of {@code AnnotatedType} objects that represent the use
3768 * of types to specify superinterfaces of the entity represented by this
3769 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3770 * superinterface in '... implements Foo' is distinct from the
3771 * <em>declaration</em> of interface Foo.)
3772 *
3773 * <p> If this {@code Class} object represents a class, the return value is
3774 * an array containing objects representing the uses of interface types to
3775 * specify interfaces implemented by the class. The order of the objects in
3776 * the array corresponds to the order of the interface types used in the
3777 * 'implements' clause of the declaration of this {@code Class} object.
3778 *
3779 * <p> If this {@code Class} object represents an interface, the return
3780 * value is an array containing objects representing the uses of interface
3781 * types to specify interfaces directly extended by the interface. The
3782 * order of the objects in the array corresponds to the order of the
3783 * interface types used in the 'extends' clause of the declaration of this
3784 * {@code Class} object.
3785 *
3786 * <p> If this {@code Class} object represents a class or interface whose
3787 * declaration does not explicitly indicate any annotated superinterfaces,
3788 * the return value is an array of length 0.
3789 *
3790 * <p> If this {@code Class} object represents either the {@code Object}
3791 * class, an array type, a primitive type, or void, the return value is an
3792 * array of length 0.
3793 *
3794 * @return an array representing the superinterfaces
3795 * @since 1.8
3796 */
3797 public AnnotatedType[] getAnnotatedInterfaces() {
3798 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3799 }
3800
3801 private native Class<?> getNestHost0();
3802
3803 /**
3804 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3805 * or interface represented by this {@code Class} object belongs.
3806 * Every class and interface belongs to exactly one nest.
3807 *
3808 * If the nest host of this class or interface has previously
3809 * been determined, then this method returns the nest host.
3810 * If the nest host of this class or interface has
3811 * not previously been determined, then this method determines the nest
3812 * host using the algorithm of JVMS 5.4.4, and returns it.
3813 *
3814 * Often, a class or interface belongs to a nest consisting only of itself,
3815 * in which case this method returns {@code this} to indicate that the class
3816 * or interface is the nest host.
3817 *
3818 * <p>If this {@code Class} object represents a primitive type, an array type,
3819 * or {@code void}, then this method returns {@code this},
3820 * indicating that the represented entity belongs to the nest consisting only of
3821 * itself, and is the nest host.
3822 *
3823 * @return the nest host of this class or interface
3824 *
3825 * @since 11
3826 * @jvms 4.7.28 The {@code NestHost} Attribute
3827 * @jvms 4.7.29 The {@code NestMembers} Attribute
3828 * @jvms 5.4.4 Access Control
3829 */
3830 public Class<?> getNestHost() {
3831 if (isPrimitive() || isArray()) {
3832 return this;
3833 }
3834 return getNestHost0();
3835 }
3836
3837 /**
3838 * Determines if the given {@code Class} is a nestmate of the
3839 * class or interface represented by this {@code Class} object.
3840 * Two classes or interfaces are nestmates
3841 * if they have the same {@linkplain #getNestHost() nest host}.
3842 *
3843 * @param c the class to check
3844 * @return {@code true} if this class and {@code c} are members of
3845 * the same nest; and {@code false} otherwise.
3846 *
3847 * @since 11
3848 */
3849 public boolean isNestmateOf(Class<?> c) {
3850 if (this == c) {
3851 return true;
3852 }
3853 if (isPrimitive() || isArray() ||
3854 c.isPrimitive() || c.isArray()) {
3855 return false;
3856 }
3857
3858 return getNestHost() == c.getNestHost();
3859 }
3860
3861 private native Class<?>[] getNestMembers0();
3862
3863 /**
3864 * Returns an array containing {@code Class} objects representing all the
3865 * classes and interfaces that are members of the nest to which the class
3866 * or interface represented by this {@code Class} object belongs.
3867 *
3868 * First, this method obtains the {@linkplain #getNestHost() nest host},
3869 * {@code H}, of the nest to which the class or interface represented by
3870 * this {@code Class} object belongs. The zeroth element of the returned
3871 * array is {@code H}.
3872 *
3873 * Then, for each class or interface {@code C} which is recorded by {@code H}
3874 * as being a member of its nest, this method attempts to obtain the {@code Class}
3875 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3876 * loader} of the current {@code Class} object), and then obtains the
3877 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3878 * The classes and interfaces which are recorded by {@code H} as being members
3879 * of its nest, and for which {@code H} can be determined as their nest host,
3880 * are indicated by subsequent elements of the returned array. The order of
3881 * such elements is unspecified. Duplicates are permitted.
3882 *
3883 * <p>If this {@code Class} object represents a primitive type, an array type,
3884 * or {@code void}, then this method returns a single-element array containing
3885 * {@code this}.
3886 *
3887 * @apiNote
3888 * The returned array includes only the nest members recorded in the {@code NestMembers}
3889 * attribute, and not any hidden classes that were added to the nest via
3890 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3891 * Lookup::defineHiddenClass}.
3892 *
3893 * @return an array of all classes and interfaces in the same nest as
3894 * this class or interface
3895 *
3896 * @since 11
3897 * @see #getNestHost()
3898 * @jvms 4.7.28 The {@code NestHost} Attribute
3899 * @jvms 4.7.29 The {@code NestMembers} Attribute
3900 */
3901 public Class<?>[] getNestMembers() {
3902 if (isPrimitive() || isArray()) {
3903 return new Class<?>[] { this };
3904 }
3905 Class<?>[] members = getNestMembers0();
3906 // Can't actually enable this due to bootstrapping issues
3907 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3908 return members;
3909 }
3910
3911 /**
3912 * Returns the descriptor string of the entity (class, interface, array class,
3913 * primitive type, or {@code void}) represented by this {@code Class} object.
3914 *
3915 * <p> If this {@code Class} object represents a class or interface,
3916 * not an array class, then:
3917 * <ul>
3918 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3919 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3920 * for the class or interface. Calling
3921 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3922 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3923 * describing this class or interface.
3924 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3925 * then the result is a string of the form:
3926 * <blockquote>
3927 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3928 * </blockquote>
3929 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3930 * encoded in internal form indicated by the {@code class} file passed to
3931 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3932 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3933 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3934 * The result string is not a type descriptor.
3935 * </ul>
3936 *
3937 * <p> If this {@code Class} object represents an array class, then
3938 * the result is a string consisting of one or more '{@code [}' characters
3939 * representing the depth of the array nesting, followed by the
3940 * descriptor string of the element type.
3941 * <ul>
3942 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3943 * or interface, then this array class can be described nominally.
3944 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3945 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3946 * describing this array class.
3947 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3948 * interface, then this array class cannot be described nominally.
3949 * The result string is not a type descriptor.
3950 * </ul>
3951 *
3952 * <p> If this {@code Class} object represents a primitive type or
3953 * {@code void}, then the result is a field descriptor string which
3954 * is a one-letter code corresponding to a primitive type or {@code void}
3955 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3956 *
3957 * @return the descriptor string for this {@code Class} object
3958 * @jvms 4.3.2 Field Descriptors
3959 * @since 12
3960 */
3961 @Override
3962 public String descriptorString() {
3963 if (isPrimitive())
3964 return Wrapper.forPrimitiveType(this).basicTypeString();
3965
3966 if (isArray()) {
3967 return "[".concat(componentType.descriptorString());
3968 } else if (isHidden()) {
3969 String name = getName();
3970 int index = name.indexOf('/');
3971 return new StringBuilder(name.length() + 2)
3972 .append('L')
3973 .append(name.substring(0, index).replace('.', '/'))
3974 .append('.')
3975 .append(name, index + 1, name.length())
3976 .append(';')
3977 .toString();
3978 } else {
3979 String name = getName().replace('.', '/');
3980 return StringConcatHelper.concat("L", name, ";");
3981 }
3982 }
3983
3984 /**
3985 * Returns the component type of this {@code Class}, if it describes
3986 * an array type, or {@code null} otherwise.
3987 *
3988 * @implSpec
3989 * Equivalent to {@link Class#getComponentType()}.
3990 *
3991 * @return a {@code Class} describing the component type, or {@code null}
3992 * if this {@code Class} does not describe an array type
3993 * @since 12
3994 */
3995 @Override
3996 public Class<?> componentType() {
3997 return getComponentType();
3998 }
3999
4000 /**
4001 * Returns a {@code Class} for an array type whose component type
4002 * is described by this {@linkplain Class}.
4003 *
4004 * @throws UnsupportedOperationException if this component type is {@linkplain
4005 * Void#TYPE void} or if the number of dimensions of the resulting array
4006 * type would exceed 255.
4007 * @return a {@code Class} describing the array type
4008 * @jvms 4.3.2 Field Descriptors
4009 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4010 * @since 12
4011 */
4012 @Override
4013 public Class<?> arrayType() {
4014 try {
4015 return Array.newInstance(this, 0).getClass();
4016 } catch (IllegalArgumentException iae) {
4017 throw new UnsupportedOperationException(iae);
4018 }
4019 }
4020
4021 /**
4022 * Returns a nominal descriptor for this instance, if one can be
4023 * constructed, or an empty {@link Optional} if one cannot be.
4024 *
4025 * @return An {@link Optional} containing the resulting nominal descriptor,
4026 * or an empty {@link Optional} if one cannot be constructed.
4027 * @since 12
4028 */
4029 @Override
4030 public Optional<ClassDesc> describeConstable() {
4031 Class<?> c = isArray() ? elementType() : this;
4032 return c.isHidden() ? Optional.empty()
4033 : Optional.of(ConstantUtils.classDesc(this));
4034 }
4035
4036 /**
4037 * Returns {@code true} if and only if the underlying class is a hidden class.
4038 *
4039 * @return {@code true} if and only if this class is a hidden class.
4040 *
4041 * @since 15
4042 * @see MethodHandles.Lookup#defineHiddenClass
4043 * @see Class##hiddenClasses Hidden Classes
4044 */
4045 @IntrinsicCandidate
4046 public native boolean isHidden();
4047
4048 /**
4049 * Returns an array containing {@code Class} objects representing the
4050 * direct subinterfaces or subclasses permitted to extend or
4051 * implement this class or interface if it is sealed. The order of such elements
4052 * is unspecified. The array is empty if this sealed class or interface has no
4053 * permitted subclass. If this {@code Class} object represents a primitive type,
4054 * {@code void}, an array type, or a class or interface that is not sealed,
4055 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4056 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4057 * returns a non-null value.
4058 *
4059 * For each class or interface {@code C} which is recorded as a permitted
4060 * direct subinterface or subclass of this class or interface,
4061 * this method attempts to obtain the {@code Class}
4062 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4063 * loader} of the current {@code Class} object).
4064 * The {@code Class} objects which can be obtained and which are direct
4065 * subinterfaces or subclasses of this class or interface,
4066 * are indicated by elements of the returned array. If a {@code Class} object
4067 * cannot be obtained, it is silently ignored, and not included in the result
4068 * array.
4069 *
4070 * @return an array of {@code Class} objects of the permitted subclasses of this class
4071 * or interface, or {@code null} if this class or interface is not sealed.
4072 *
4073 * @jls 8.1 Class Declarations
4074 * @jls 9.1 Interface Declarations
4075 * @since 17
4076 */
4077 public Class<?>[] getPermittedSubclasses() {
4078 Class<?>[] subClasses;
4079 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4080 return null;
4081 }
4082 if (subClasses.length > 0) {
4083 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4084 subClasses = Arrays.stream(subClasses)
4085 .filter(this::isDirectSubType)
4086 .toArray(s -> new Class<?>[s]);
4087 }
4088 }
4089 return subClasses;
4090 }
4091
4092 private boolean isDirectSubType(Class<?> c) {
4093 if (isInterface()) {
4094 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4095 if (i == this) {
4096 return true;
4097 }
4098 }
4099 } else {
4100 return c.getSuperclass() == this;
4101 }
4102 return false;
4103 }
4104
4105 /**
4106 * Returns {@code true} if and only if this {@code Class} object represents
4107 * a sealed class or interface. If this {@code Class} object represents a
4108 * primitive type, {@code void}, or an array type, this method returns
4109 * {@code false}. A sealed class or interface has (possibly zero) permitted
4110 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4111 * possibly empty value for a sealed class or interface.
4112 *
4113 * @return {@code true} if and only if this {@code Class} object represents
4114 * a sealed class or interface.
4115 *
4116 * @jls 8.1 Class Declarations
4117 * @jls 9.1 Interface Declarations
4118 * @since 17
4119 */
4120 public boolean isSealed() {
4121 if (isArray() || isPrimitive()) {
4122 return false;
4123 }
4124 return getPermittedSubclasses() != null;
4125 }
4126
4127 private native Class<?>[] getPermittedSubclasses0();
4128
4129 /*
4130 * Return the class's major and minor class file version packed into an int.
4131 * The high order 16 bits contain the class's minor version. The low order
4132 * 16 bits contain the class's major version.
4133 *
4134 * If the class is an array type then the class file version of its element
4135 * type is returned. If the class is a primitive type then the latest class
4136 * file major version is returned and zero is returned for the minor version.
4137 */
4138 int getClassFileVersion() {
4139 Class<?> c = isArray() ? elementType() : this;
4140 return c.getClassFileVersion0();
4141 }
4142
4143 private native int getClassFileVersion0();
4144
4145 /**
4146 * Return the access flags as they were in the class's bytecode, including
4147 * the original setting of ACC_SUPER.
4148 *
4149 * If this {@code Class} object represents a primitive type or
4150 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
4151 * {@code FINAL}.
4152 * If this {@code Class} object represents an array type, return 0.
4153 */
4154 int getClassFileAccessFlags() {
4155 return classFileAccessFlags;
4156 }
4157
4158 // Validates the length of the class name and throws an exception if it exceeds the maximum allowed length.
4159 private static void validateClassNameLength(String name) throws ClassNotFoundException {
4160 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
4161 throw new ClassNotFoundException(
4162 "Class name length exceeds limit of "
4163 + ModifiedUtf.CONSTANT_POOL_UTF8_MAX_BYTES
4164 + ": " + name.substring(0,256) + "...");
4165 }
4166 }
4167 }