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