1 /*
2 * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.constant.ClassDesc;
30 import java.lang.constant.ConstantDescs;
31 import java.lang.invoke.TypeDescriptor;
32 import java.lang.invoke.MethodHandles;
33 import java.lang.ref.SoftReference;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.ObjectStreamField;
37 import java.lang.reflect.AnnotatedElement;
38 import java.lang.reflect.AnnotatedType;
39 import java.lang.reflect.AccessFlag;
40 import java.lang.reflect.Array;
41 import java.lang.reflect.ClassFileFormatVersion;
42 import java.lang.reflect.Constructor;
43 import java.lang.reflect.Executable;
44 import java.lang.reflect.Field;
45 import java.lang.reflect.GenericArrayType;
46 import java.lang.reflect.GenericDeclaration;
47 import java.lang.reflect.InvocationTargetException;
48 import java.lang.reflect.Member;
49 import java.lang.reflect.Method;
50 import java.lang.reflect.Modifier;
51 import java.lang.reflect.Proxy;
52 import java.lang.reflect.RecordComponent;
53 import java.lang.reflect.Type;
54 import java.lang.reflect.TypeVariable;
55 import java.lang.constant.Constable;
56 import java.net.URL;
57 import java.security.AllPermission;
58 import java.security.Permissions;
59 import java.security.ProtectionDomain;
60 import java.util.ArrayList;
61 import java.util.Arrays;
62 import java.util.Collection;
63 import java.util.HashMap;
64 import java.util.LinkedHashMap;
65 import java.util.LinkedHashSet;
66 import java.util.List;
67 import java.util.Map;
68 import java.util.Objects;
69 import java.util.Optional;
70 import java.util.Set;
71 import java.util.stream.Collectors;
72
73 import jdk.internal.constant.ConstantUtils;
74 import jdk.internal.javac.PreviewFeature;
75 import jdk.internal.loader.BootLoader;
76 import jdk.internal.loader.BuiltinClassLoader;
77 import jdk.internal.misc.PreviewFeatures;
78 import jdk.internal.misc.Unsafe;
79 import jdk.internal.module.Resources;
80 import jdk.internal.reflect.CallerSensitive;
81 import jdk.internal.reflect.CallerSensitiveAdapter;
82 import jdk.internal.reflect.ConstantPool;
83 import jdk.internal.reflect.Reflection;
84 import jdk.internal.reflect.ReflectionFactory;
85 import jdk.internal.vm.annotation.IntrinsicCandidate;
86 import jdk.internal.vm.annotation.Stable;
87
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.repository.MethodRepository;
93 import sun.reflect.generics.repository.ConstructorRepository;
94 import sun.reflect.generics.scope.ClassScope;
95 import sun.reflect.annotation.*;
96
97 /**
98 * Instances of the class {@code Class} represent classes and
99 * interfaces in a running Java application. An enum class and a record
100 * class are kinds of class; an annotation interface is a kind of
101 * interface. Every array also belongs to a class that is reflected as
102 * a {@code Class} object that is shared by all arrays with the same
103 * element type and number of dimensions. The primitive Java types
104 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
105 * int}, {@code long}, {@code float}, and {@code double}), and the
106 * keyword {@code void} are also represented as {@code Class} objects.
107 *
108 * <p> {@code Class} has no public constructor. Instead a {@code Class}
109 * object is constructed automatically by the Java Virtual Machine when
110 * a class is derived from the bytes of a {@code class} file through
111 * the invocation of one of the following methods:
112 * <ul>
113 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
114 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
115 * java.lang.invoke.MethodHandles.Lookup::defineClass}
116 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
117 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
118 * </ul>
119 *
120 * <p> The methods of class {@code Class} expose many characteristics of a
121 * class or interface. Most characteristics are derived from the {@code class}
122 * file that the class loader passed to the Java Virtual Machine or
123 * from the {@code class} file passed to {@code Lookup::defineClass}
124 * or {@code Lookup::defineHiddenClass}.
125 * A few characteristics are determined by the class loading environment
126 * at run time, such as the module returned by {@link #getModule() getModule()}.
127 *
128 * <p> The following example uses a {@code Class} object to print the
129 * class name of an object:
130 *
131 * {@snippet lang="java" :
132 * void printClassName(Object obj) {
133 * System.out.println("The class of " + obj +
134 * " is " + obj.getClass().getName());
135 * }}
136 *
137 * It is also possible to get the {@code Class} object for a named
138 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
139 * (JLS {@jls 15.8.2}).
140 * For example:
141 *
142 * {@snippet lang="java" :
143 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
144 * }
145 *
146 * <p> Some methods of class {@code Class} expose whether the declaration of
147 * a class or interface in Java source code was <em>enclosed</em> within
148 * another declaration. Other methods describe how a class or interface
149 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
150 * classes and interfaces, in the same run-time package, that
151 * allow mutual access to their {@code private} members.
152 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
153 * (JVMS {@jvms 4.7.29}).
154 * One nestmate acts as the
155 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
156 * belong to the nest; each of them in turn records it as the nest host.
157 * The classes and interfaces which belong to a nest, including its host, are
158 * determined when
159 * {@code class} files are generated, for example, a Java compiler
160 * will typically record a top-level class as the host of a nest where the
161 * other members are the classes and interfaces whose declarations are
162 * enclosed within the top-level class declaration.
163 *
164 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
165 * A class or interface created by the invocation of
166 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
167 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
168 * class or interface.
169 * All kinds of class, including enum classes and record classes, may be
170 * hidden classes; all kinds of interface, including annotation interfaces,
171 * may be hidden interfaces.
172 *
173 * The {@linkplain #getName() name of a hidden class or interface} is
174 * not a {@linkplain ClassLoader##binary-name binary name},
175 * which means the following:
176 * <ul>
177 * <li>A hidden class or interface cannot be referenced by the constant pools
178 * of other classes and interfaces.
179 * <li>A hidden class or interface cannot be described in
180 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
181 * {@link #describeConstable() Class::describeConstable},
182 * {@link ClassDesc#of(String) ClassDesc::of}, or
183 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
184 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
185 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
186 * </ul>
187 *
188 * A hidden class or interface is never an array class, but may be
189 * the element type of an array. In all other respects, the fact that
190 * a class or interface is hidden has no bearing on the characteristics
191 * exposed by the methods of class {@code Class}.
192 *
193 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
194 *
195 * Conventionally, a Java compiler, starting from a source file for an
196 * implicitly declared class, say {@code HelloWorld.java}, creates a
197 * similarly-named {@code class} file, {@code HelloWorld.class}, where
198 * the class stored in that {@code class} file is named {@code
199 * "HelloWorld"}, matching the base names of the source and {@code
200 * class} files.
201 *
202 * For the {@code Class} object of an implicitly declared class {@code
203 * HelloWorld}, the methods to get the {@linkplain #getName name} and
204 * {@linkplain #getTypeName type name} return results
205 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
206 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
207 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
208 *
209 * @param <T> the type of the class modeled by this {@code Class}
210 * object. For example, the type of {@code String.class} is {@code
211 * Class<String>}. Use {@code Class<?>} if the class being modeled is
212 * unknown.
213 *
214 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
215 * @since 1.0
216 */
217 public final class Class<T> implements java.io.Serializable,
218 GenericDeclaration,
219 Type,
220 AnnotatedElement,
221 TypeDescriptor.OfField<Class<?>>,
222 Constable {
223 private static final int ANNOTATION = 0x00002000;
224 private static final int ENUM = 0x00004000;
225 private static final int SYNTHETIC = 0x00001000;
226
227 private static native void registerNatives();
228 static {
229 runtimeSetup();
230 }
231
232 // Called from JVM when loading an AOT cache
233 private static void runtimeSetup() {
234 registerNatives();
235 }
236
237 /*
238 * Private constructor. Only the Java Virtual Machine creates Class objects.
239 * This constructor is not used and prevents the default constructor being
240 * generated.
241 */
242 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim) {
243 // Initialize final field for classLoader. The initialization value of non-null
244 // prevents future JIT optimizations from assuming this final field is null.
245 // The following assignments are done directly by the VM without calling this constructor.
246 classLoader = loader;
247 componentType = arrayComponentType;
248 modifiers = mods;
249 protectionDomain = pd;
250 primitive = isPrim;
251 }
252
253 /**
254 * Converts the object to a string. The string representation is the
255 * string "class" or "interface", followed by a space, and then by the
256 * name of the class in the format returned by {@code getName}.
257 * If this {@code Class} object represents a primitive type,
258 * this method returns the name of the primitive type. If
259 * this {@code Class} object represents void this method returns
260 * "void". If this {@code Class} object represents an array type,
261 * this method returns "class " followed by {@code getName}.
262 *
263 * @return a string representation of this {@code Class} object.
264 */
265 public String toString() {
266 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
267 return kind.concat(getName());
268 }
269
270 /**
271 * Returns a string describing this {@code Class}, including
272 * information about modifiers, {@link #isSealed() sealed}/{@code
273 * non-sealed} status, and type parameters.
274 *
275 * The string is formatted as a list of type modifiers, if any,
276 * followed by the kind of type (empty string for primitive types
277 * and {@code class}, {@code enum}, {@code interface},
278 * {@code @interface}, or {@code record} as appropriate), followed
279 * by the type's name, followed by an angle-bracketed
280 * comma-separated list of the type's type parameters, if any,
281 * including informative bounds on the type parameters, if any.
282 *
283 * A space is used to separate modifiers from one another and to
284 * separate any modifiers from the kind of type. The modifiers
285 * occur in canonical order. If there are no type parameters, the
286 * type parameter list is elided.
287 *
288 * For an array type, the string starts with the type name,
289 * followed by an angle-bracketed comma-separated list of the
290 * type's type parameters, if any, followed by a sequence of
291 * {@code []} characters, one set of brackets per dimension of
292 * the array.
293 *
294 * <p>Note that since information about the runtime representation
295 * of a type is being generated, modifiers not present on the
296 * originating source code or illegal on the originating source
297 * code may be present.
298 *
299 * @return a string describing this {@code Class}, including
300 * information about modifiers and type parameters
301 *
302 * @since 1.8
303 */
304 public String toGenericString() {
305 if (isPrimitive()) {
306 return toString();
307 } else {
308 StringBuilder sb = new StringBuilder();
309 Class<?> component = this;
310 int arrayDepth = 0;
311
312 if (isArray()) {
313 do {
314 arrayDepth++;
315 component = component.getComponentType();
316 } while (component.isArray());
317 sb.append(component.getName());
318 } else {
319 // Class modifiers are a superset of interface modifiers
320 int modifiers = getModifiers() & Modifier.classModifiers();
321 // Modifier.toString() below mis-interprets SYNCHRONIZED, STRICT, and VOLATILE bits
322 modifiers &= ~(Modifier.SYNCHRONIZED | Modifier.STRICT | Modifier.VOLATILE);
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 (isValue()) {
337 sb.append("value ");
338 }
339 if (isInterface()) { // Note: all annotation interfaces are interfaces
340 sb.append("interface");
341 } else {
342 if (isEnum())
343 sb.append("enum");
344 else if (isRecord())
345 sb.append("record");
346 else
347 sb.append("class");
348 }
349 sb.append(' ');
350 sb.append(getName());
351 }
352
353 TypeVariable<?>[] typeparms = component.getTypeParameters();
354 if (typeparms.length > 0) {
355 sb.append(Arrays.stream(typeparms)
356 .map(Class::typeVarBounds)
357 .collect(Collectors.joining(",", "<", ">")));
358 }
359
360 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
361
362 return sb.toString();
363 }
364 }
365
366 private void addSealingInfo(int modifiers, StringBuilder sb) {
367 // A class can be final XOR sealed XOR non-sealed.
368 if (Modifier.isFinal(modifiers)) {
369 return; // no-op
370 } else {
371 if (isSealed()) {
372 sb.append("sealed ");
373 return;
374 } else {
375 // Check for sealed ancestor, which implies this class
376 // is non-sealed.
377 if (hasSealedAncestor(this)) {
378 sb.append("non-sealed ");
379 }
380 }
381 }
382 }
383
384 private boolean hasSealedAncestor(Class<?> clazz) {
385 // From JLS 8.1.1.2:
386 // "It is a compile-time error if a class has a sealed direct
387 // superclass or a sealed direct superinterface, and is not
388 // declared final, sealed, or non-sealed either explicitly or
389 // implicitly.
390 // Thus, an effect of the sealed keyword is to force all
391 // direct subclasses to explicitly declare whether they are
392 // final, sealed, or non-sealed. This avoids accidentally
393 // exposing a sealed class hierarchy to unwanted subclassing."
394
395 // Therefore, will just check direct superclass and
396 // superinterfaces.
397 var superclass = clazz.getSuperclass();
398 if (superclass != null && superclass.isSealed()) {
399 return true;
400 }
401 for (var superinterface : clazz.getInterfaces()) {
402 if (superinterface.isSealed()) {
403 return true;
404 }
405 }
406 return false;
407 }
408
409 static String typeVarBounds(TypeVariable<?> typeVar) {
410 Type[] bounds = typeVar.getBounds();
411 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
412 return typeVar.getName();
413 } else {
414 return typeVar.getName() + " extends " +
415 Arrays.stream(bounds)
416 .map(Type::getTypeName)
417 .collect(Collectors.joining(" & "));
418 }
419 }
420
421 /**
422 * Returns the {@code Class} object associated with the class or
423 * interface with the given string name. Invoking this method is
424 * equivalent to:
425 *
426 * {@snippet lang="java" :
427 * Class.forName(className, true, currentLoader)
428 * }
429 *
430 * where {@code currentLoader} denotes the defining class loader of
431 * the current class.
432 *
433 * <p> For example, the following code fragment returns the
434 * runtime {@code Class} object for the class named
435 * {@code java.lang.Thread}:
436 *
437 * {@snippet lang="java" :
438 * Class<?> t = Class.forName("java.lang.Thread");
439 * }
440 * <p>
441 * A call to {@code forName("X")} causes the class named
442 * {@code X} to be initialized.
443 *
444 * <p>
445 * In cases where this method is called from a context where there is no
446 * caller frame on the stack (e.g. when called directly from a JNI
447 * attached thread), the system class loader is used.
448 *
449 * @param className the {@linkplain ClassLoader##binary-name binary name}
450 * of the class or the string representing an array type
451 * @return the {@code Class} object for the class with the
452 * specified name.
453 * @throws LinkageError if the linkage fails
454 * @throws ExceptionInInitializerError if the initialization provoked
455 * by this method fails
456 * @throws ClassNotFoundException if the class cannot be located
457 *
458 * @jls 12.2 Loading of Classes and Interfaces
459 * @jls 12.3 Linking of Classes and Interfaces
460 * @jls 12.4 Initialization of Classes and Interfaces
461 */
462 @CallerSensitive
463 public static Class<?> forName(String className)
464 throws ClassNotFoundException {
465 Class<?> caller = Reflection.getCallerClass();
466 return forName(className, caller);
467 }
468
469 // Caller-sensitive adapter method for reflective invocation
470 @CallerSensitiveAdapter
471 private static Class<?> forName(String className, Class<?> caller)
472 throws ClassNotFoundException {
473 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
474 : ClassLoader.getClassLoader(caller);
475 return forName0(className, true, loader, caller);
476 }
477
478 /**
479 * Returns the {@code Class} object associated with the class or
480 * interface with the given string name, using the given class loader.
481 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
482 * this method attempts to locate and load the class or interface. The specified
483 * class loader is used to load the class or interface. If the parameter
484 * {@code loader} is {@code null}, the class is loaded through the bootstrap
485 * class loader. The class is initialized only if the
486 * {@code initialize} parameter is {@code true} and if it has
487 * not been initialized earlier.
488 *
489 * <p> This method cannot be used to obtain any of the {@code Class} objects
490 * representing primitive types or void, hidden classes or interfaces,
491 * or array classes whose element type is a hidden class or interface.
492 * If {@code name} denotes a primitive type or void, for example {@code I},
493 * an attempt will be made to locate a user-defined class in the unnamed package
494 * whose name is {@code I} instead.
495 * To obtain a {@code Class} object for a named primitive type
496 * such as {@code int} or {@code long} use {@link
497 * #forPrimitiveName(String)}.
498 *
499 * <p> To obtain the {@code Class} object associated with an array class,
500 * the name consists of one or more {@code '['} representing the depth
501 * of the array nesting, followed by the element type as encoded in
502 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
503 *
504 * <p> Examples:
505 * {@snippet lang="java" :
506 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
507 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
508 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
509 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
510 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
511 * }
512 *
513 * <p> A call to {@code getName()} on the {@code Class} object returned
514 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
515 *
516 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
517 * named <i>N</i> to be loaded but not initialized regardless of the value
518 * of the {@code initialize} parameter.
519 *
520 * @apiNote
521 * This method throws errors related to loading, linking or initializing
522 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
523 * <cite>The Java Language Specification</cite>.
524 * In addition, this method does not check whether the requested class
525 * is accessible to its caller.
526 *
527 * @param name the {@linkplain ClassLoader##binary-name binary name}
528 * of the class or the string representing an array class
529 *
530 * @param initialize if {@code true} the class will be initialized
531 * (which implies linking). See Section {@jls
532 * 12.4} of <cite>The Java Language
533 * Specification</cite>.
534 * @param loader class loader from which the class must be loaded
535 * @return class object representing the desired class
536 *
537 * @throws LinkageError if the linkage fails
538 * @throws ExceptionInInitializerError if the initialization provoked
539 * by this method fails
540 * @throws ClassNotFoundException if the class cannot be located by
541 * the specified class loader
542 *
543 * @see java.lang.Class#forName(String)
544 * @see java.lang.ClassLoader
545 *
546 * @jls 12.2 Loading of Classes and Interfaces
547 * @jls 12.3 Linking of Classes and Interfaces
548 * @jls 12.4 Initialization of Classes and Interfaces
549 * @jls 13.1 The Form of a Binary
550 * @since 1.2
551 */
552 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
553 throws ClassNotFoundException
554 {
555 return forName0(name, initialize, loader, null);
556 }
557
558 /** Called after security check for system loader access checks have been made. */
559 private static native Class<?> forName0(String name, boolean initialize,
560 ClassLoader loader,
561 Class<?> caller)
562 throws ClassNotFoundException;
563
564
565 /**
566 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
567 * binary name} in the given module.
568 *
569 * <p> This method attempts to locate and load the class or interface.
570 * It does not link the class, and does not run the class initializer.
571 * If the class is not found, this method returns {@code null}. </p>
572 *
573 * <p> If the class loader of the given module defines other modules and
574 * the given name is a class defined in a different module, this method
575 * returns {@code null} after the class is loaded. </p>
576 *
577 * <p> This method does not check whether the requested class is
578 * accessible to its caller. </p>
579 *
580 * @apiNote
581 * This method does not support loading of array types, unlike
582 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
583 * a binary name. This method returns {@code null} on failure rather than
584 * throwing a {@link ClassNotFoundException}, as is done by
585 * the {@link #forName(String, boolean, ClassLoader)} method.
586 *
587 * @param module A module
588 * @param name The {@linkplain ClassLoader##binary-name binary name}
589 * of the class
590 * @return {@code Class} object of the given name defined in the given module;
591 * {@code null} if not found.
592 *
593 * @throws NullPointerException if the given module or name is {@code null}
594 *
595 * @throws LinkageError if the linkage fails
596 *
597 * @jls 12.2 Loading of Classes and Interfaces
598 * @jls 12.3 Linking of Classes and Interfaces
599 * @since 9
600 */
601 public static Class<?> forName(Module module, String name) {
602 Objects.requireNonNull(module);
603 Objects.requireNonNull(name);
604
605 ClassLoader cl = module.getClassLoader();
606 if (cl != null) {
607 return cl.loadClass(module, name);
608 } else {
609 return BootLoader.loadClass(module, name);
610 }
611 }
612
613 /**
614 * {@return {@code true} if this {@code Class} object represents an identity
615 * class or interface; otherwise {@code false}}
616 *
617 * If this {@code Class} object represents an array type, then this method
618 * returns {@code true}.
619 * If this {@code Class} object represents a primitive type, or {@code void},
620 * then this method returns {@code false}.
621 *
622 * @since Valhalla
623 */
624 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true)
625 public native boolean isIdentity();
626
627 /**
628 * {@return {@code true} if this {@code Class} object represents a value
629 * class; otherwise {@code false}}
630 *
631 * If this {@code Class} object represents an array type, an interface,
632 * a primitive type, or {@code void}, then this method returns {@code false}.
633 *
634 * @since Valhalla
635 */
636 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true)
637 public boolean isValue() {
638 if (!PreviewFeatures.isEnabled()) {
639 return false;
640 }
641 if (isPrimitive() || isArray() || isInterface())
642 return false;
643 return ((getModifiers() & Modifier.IDENTITY) == 0);
644 }
645
646 /**
647 * {@return the {@code Class} object associated with the
648 * {@linkplain #isPrimitive() primitive type} of the given name}
649 * If the argument is not the name of a primitive type, {@code
650 * null} is returned.
651 *
652 * @param primitiveName the name of the primitive type to find
653 *
654 * @throws NullPointerException if the argument is {@code null}
655 *
656 * @jls 4.2 Primitive Types and Values
657 * @jls 15.8.2 Class Literals
658 * @since 22
659 */
660 public static Class<?> forPrimitiveName(String primitiveName) {
661 return switch(primitiveName) {
662 // Integral types
663 case "int" -> int.class;
664 case "long" -> long.class;
665 case "short" -> short.class;
666 case "char" -> char.class;
667 case "byte" -> byte.class;
668
669 // Floating-point types
670 case "float" -> float.class;
671 case "double" -> double.class;
672
673 // Other types
674 case "boolean" -> boolean.class;
675 case "void" -> void.class;
676
677 default -> null;
678 };
679 }
680
681 /**
682 * Creates a new instance of the class represented by this {@code Class}
683 * object. The class is instantiated as if by a {@code new}
684 * expression with an empty argument list. The class is initialized if it
685 * has not already been initialized.
686 *
687 * @deprecated This method propagates any exception thrown by the
688 * nullary constructor, including a checked exception. Use of
689 * this method effectively bypasses the compile-time exception
690 * checking that would otherwise be performed by the compiler.
691 * The {@link
692 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
693 * Constructor.newInstance} method avoids this problem by wrapping
694 * any exception thrown by the constructor in a (checked) {@link
695 * java.lang.reflect.InvocationTargetException}.
696 *
697 * <p>The call
698 *
699 * {@snippet lang="java" :
700 * clazz.newInstance()
701 * }
702 *
703 * can be replaced by
704 *
705 * {@snippet lang="java" :
706 * clazz.getDeclaredConstructor().newInstance()
707 * }
708 *
709 * The latter sequence of calls is inferred to be able to throw
710 * the additional exception types {@link
711 * InvocationTargetException} and {@link
712 * NoSuchMethodException}. Both of these exception types are
713 * subclasses of {@link ReflectiveOperationException}.
714 *
715 * @return a newly allocated instance of the class represented by this
716 * object.
717 * @throws IllegalAccessException if the class or its nullary
718 * constructor is not accessible.
719 * @throws InstantiationException
720 * if this {@code Class} represents an abstract class,
721 * an interface, an array class, a primitive type, or void;
722 * or if the class has no nullary constructor;
723 * or if the instantiation fails for some other reason.
724 * @throws ExceptionInInitializerError if the initialization
725 * provoked by this method fails.
726 */
727 @CallerSensitive
728 @Deprecated(since="9")
729 public T newInstance()
730 throws InstantiationException, IllegalAccessException
731 {
732 // Constructor lookup
733 Constructor<T> tmpConstructor = cachedConstructor;
734 if (tmpConstructor == null) {
735 if (this == Class.class) {
736 throw new IllegalAccessException(
737 "Can not call newInstance() on the Class for java.lang.Class"
738 );
739 }
740 try {
741 Class<?>[] empty = {};
742 final Constructor<T> c = getReflectionFactory().copyConstructor(
743 getConstructor0(empty, Member.DECLARED));
744 // Disable accessibility checks on the constructor
745 // access check is done with the true caller
746 c.setAccessible(true);
747 cachedConstructor = tmpConstructor = c;
748 } catch (NoSuchMethodException e) {
749 throw (InstantiationException)
750 new InstantiationException(getName()).initCause(e);
751 }
752 }
753
754 try {
755 Class<?> caller = Reflection.getCallerClass();
756 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
757 } catch (InvocationTargetException e) {
758 Unsafe.getUnsafe().throwException(e.getTargetException());
759 // Not reached
760 return null;
761 }
762 }
763
764 private transient volatile Constructor<T> cachedConstructor;
765
766 /**
767 * Determines if the specified {@code Object} is assignment-compatible
768 * with the object represented by this {@code Class}. This method is
769 * the dynamic equivalent of the Java language {@code instanceof}
770 * operator. The method returns {@code true} if the specified
771 * {@code Object} argument is non-null and can be cast to the
772 * reference type represented by this {@code Class} object without
773 * raising a {@code ClassCastException.} It returns {@code false}
774 * otherwise.
775 *
776 * <p> Specifically, if this {@code Class} object represents a
777 * declared class, this method returns {@code true} if the specified
778 * {@code Object} argument is an instance of the represented class (or
779 * of any of its subclasses); it returns {@code false} otherwise. If
780 * this {@code Class} object represents an array class, this method
781 * returns {@code true} if the specified {@code Object} argument
782 * can be converted to an object of the array class by an identity
783 * conversion or by a widening reference conversion; it returns
784 * {@code false} otherwise. If this {@code Class} object
785 * represents an interface, this method returns {@code true} if the
786 * class or any superclass of the specified {@code Object} argument
787 * implements this interface; it returns {@code false} otherwise. If
788 * this {@code Class} object represents a primitive type, this method
789 * returns {@code false}.
790 *
791 * @param obj the object to check
792 * @return true if {@code obj} is an instance of this class
793 *
794 * @since 1.1
795 */
796 @IntrinsicCandidate
797 public native boolean isInstance(Object obj);
798
799
800 /**
801 * Determines if the class or interface represented by this
802 * {@code Class} object is either the same as, or is a superclass or
803 * superinterface of, the class or interface represented by the specified
804 * {@code Class} parameter. It returns {@code true} if so;
805 * otherwise it returns {@code false}. If this {@code Class}
806 * object represents a primitive type, this method returns
807 * {@code true} if the specified {@code Class} parameter is
808 * exactly this {@code Class} object; otherwise it returns
809 * {@code false}.
810 *
811 * <p> Specifically, this method tests whether the type represented by the
812 * specified {@code Class} parameter can be converted to the type
813 * represented by this {@code Class} object via an identity conversion
814 * or via a widening reference conversion. See <cite>The Java Language
815 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
816 * for details.
817 *
818 * @param cls the {@code Class} object to be checked
819 * @return the {@code boolean} value indicating whether objects of the
820 * type {@code cls} can be assigned to objects of this class
821 * @throws NullPointerException if the specified Class parameter is
822 * null.
823 * @since 1.1
824 */
825 @IntrinsicCandidate
826 public native boolean isAssignableFrom(Class<?> cls);
827
828
829 /**
830 * Determines if this {@code Class} object represents an
831 * interface type.
832 *
833 * @return {@code true} if this {@code Class} object represents an interface;
834 * {@code false} otherwise.
835 */
836 public boolean isInterface() {
837 return Modifier.isInterface(modifiers);
838 }
839
840
841 /**
842 * Determines if this {@code Class} object represents an array class.
843 *
844 * @return {@code true} if this {@code Class} object represents an array class;
845 * {@code false} otherwise.
846 * @since 1.1
847 */
848 public boolean isArray() {
849 return componentType != null;
850 }
851
852
853 /**
854 * Determines if this {@code Class} object represents a primitive
855 * type or void.
856 *
857 * <p> There are nine predefined {@code Class} objects to
858 * represent the eight primitive types and void. These are
859 * created by the Java Virtual Machine, and have the same
860 * {@linkplain #getName() names} as the primitive types that they
861 * represent, namely {@code boolean}, {@code byte}, {@code char},
862 * {@code short}, {@code int}, {@code long}, {@code float}, and
863 * {@code double}.
864 *
865 * <p>No other class objects are considered primitive.
866 *
867 * @apiNote
868 * A {@code Class} object represented by a primitive type can be
869 * accessed via the {@code TYPE} public static final variables
870 * defined in the primitive wrapper classes such as {@link
871 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
872 * language, the objects may be referred to by a class literal
873 * expression such as {@code int.class}. The {@code Class} object
874 * for void can be expressed as {@code void.class} or {@link
875 * java.lang.Void#TYPE Void.TYPE}.
876 *
877 * @return true if and only if this class represents a primitive type
878 *
879 * @see java.lang.Boolean#TYPE
880 * @see java.lang.Character#TYPE
881 * @see java.lang.Byte#TYPE
882 * @see java.lang.Short#TYPE
883 * @see java.lang.Integer#TYPE
884 * @see java.lang.Long#TYPE
885 * @see java.lang.Float#TYPE
886 * @see java.lang.Double#TYPE
887 * @see java.lang.Void#TYPE
888 * @since 1.1
889 * @jls 15.8.2 Class Literals
890 */
891 public boolean isPrimitive() {
892 return primitive;
893 }
894
895 /**
896 * Returns true if this {@code Class} object represents an annotation
897 * interface. Note that if this method returns true, {@link #isInterface()}
898 * would also return true, as all annotation interfaces are also interfaces.
899 *
900 * @return {@code true} if this {@code Class} object represents an annotation
901 * interface; {@code false} otherwise
902 * @since 1.5
903 */
904 public boolean isAnnotation() {
905 return (getModifiers() & ANNOTATION) != 0;
906 }
907
908 /**
909 *{@return {@code true} if and only if this class has the synthetic modifier
910 * bit set}
911 *
912 * @jls 13.1 The Form of a Binary
913 * @jvms 4.1 The {@code ClassFile} Structure
914 * @see <a
915 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
916 * programming language and JVM modeling in core reflection</a>
917 * @since 1.5
918 */
919 public boolean isSynthetic() {
920 return (getModifiers() & SYNTHETIC) != 0;
921 }
922
923 /**
924 * Returns the name of the entity (class, interface, array class,
925 * primitive type, or void) represented by this {@code Class} object.
926 *
927 * <p> If this {@code Class} object represents a class or interface,
928 * not an array class, then:
929 * <ul>
930 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
931 * then the {@linkplain ClassLoader##binary-name binary name}
932 * of the class or interface is returned.
933 * <li> If the class or interface is hidden, then the result is a string
934 * of the form: {@code N + '/' + <suffix>}
935 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
936 * indicated by the {@code class} file passed to
937 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
938 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
939 * </ul>
940 *
941 * <p> If this {@code Class} object represents an array class, then
942 * the result is a string consisting of one or more '{@code [}' characters
943 * representing the depth of the array nesting, followed by the element
944 * type as encoded using the following table:
945 *
946 * <blockquote><table class="striped" id="nameFormat">
947 * <caption style="display:none">Element types and encodings</caption>
948 * <thead>
949 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
950 * </thead>
951 * <tbody style="text-align:left">
952 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
953 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
954 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
955 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
956 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
957 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
958 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
959 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
960 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
961 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
962 * </tbody>
963 * </table></blockquote>
964 *
965 * <p> If this {@code Class} object represents a primitive type or {@code void},
966 * then the result is a string with the same spelling as the Java language
967 * keyword which corresponds to the primitive type or {@code void}.
968 *
969 * <p> Examples:
970 * <blockquote><pre>
971 * String.class.getName()
972 * returns "java.lang.String"
973 * Character.UnicodeBlock.class.getName()
974 * returns "java.lang.Character$UnicodeBlock"
975 * byte.class.getName()
976 * returns "byte"
977 * (new Object[3]).getClass().getName()
978 * returns "[Ljava.lang.Object;"
979 * (new int[3][4][5][6][7][8][9]).getClass().getName()
980 * returns "[[[[[[[I"
981 * </pre></blockquote>
982 *
983 * @apiNote
984 * Distinct class objects can have the same name but different class loaders.
985 *
986 * @return the name of the class, interface, or other entity
987 * represented by this {@code Class} object.
988 * @jls 13.1 The Form of a Binary
989 */
990 public String getName() {
991 String name = this.name;
992 return name != null ? name : initClassName();
993 }
994
995 // Cache the name to reduce the number of calls into the VM.
996 // This field would be set by VM itself during initClassName call.
997 private transient String name;
998 private native String initClassName();
999
1000 /**
1001 * Returns the class loader for the class. Some implementations may use
1002 * null to represent the bootstrap class loader. This method will return
1003 * null in such implementations if this class was loaded by the bootstrap
1004 * class loader.
1005 *
1006 * <p>If this {@code Class} object
1007 * represents a primitive type or void, null is returned.
1008 *
1009 * @return the class loader that loaded the class or interface
1010 * represented by this {@code Class} object.
1011 * @see java.lang.ClassLoader
1012 */
1013 public ClassLoader getClassLoader() {
1014 return classLoader;
1015 }
1016
1017 // Package-private to allow ClassLoader access
1018 ClassLoader getClassLoader0() { return classLoader; }
1019
1020 /**
1021 * Returns the module that this class or interface is a member of.
1022 *
1023 * If this class represents an array type then this method returns the
1024 * {@code Module} for the element type. If this class represents a
1025 * primitive type or void, then the {@code Module} object for the
1026 * {@code java.base} module is returned.
1027 *
1028 * If this class is in an unnamed module then the {@linkplain
1029 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1030 * loader for this class is returned.
1031 *
1032 * @return the module that this class or interface is a member of
1033 *
1034 * @since 9
1035 */
1036 public Module getModule() {
1037 return module;
1038 }
1039
1040 // set by VM
1041 @Stable
1042 private transient Module module;
1043
1044 // Initialized in JVM not by private constructor
1045 // This field is filtered from reflection access, i.e. getDeclaredField
1046 // will throw NoSuchFieldException
1047 private final ClassLoader classLoader;
1048
1049 private transient Object classData; // Set by VM
1050 private transient Object[] signers; // Read by VM, mutable
1051 private final transient char modifiers; // Set by the VM
1052 private final transient boolean primitive; // Set by the VM if the Class is a primitive type.
1053
1054 // package-private
1055 Object getClassData() {
1056 return classData;
1057 }
1058
1059 /**
1060 * Returns an array of {@code TypeVariable} objects that represent the
1061 * type variables declared by the generic declaration represented by this
1062 * {@code GenericDeclaration} object, in declaration order. Returns an
1063 * array of length 0 if the underlying generic declaration declares no type
1064 * variables.
1065 *
1066 * @return an array of {@code TypeVariable} objects that represent
1067 * the type variables declared by this generic declaration
1068 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1069 * signature of this generic declaration does not conform to
1070 * the format specified in section {@jvms 4.7.9} of
1071 * <cite>The Java Virtual Machine Specification</cite>
1072 * @since 1.5
1073 */
1074 @SuppressWarnings("unchecked")
1075 public TypeVariable<Class<T>>[] getTypeParameters() {
1076 ClassRepository info = getGenericInfo();
1077 if (info != null)
1078 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1079 else
1080 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1081 }
1082
1083
1084 /**
1085 * Returns the {@code Class} representing the direct superclass of the
1086 * entity (class, interface, primitive type or void) represented by
1087 * this {@code Class}. If this {@code Class} represents either the
1088 * {@code Object} class, an interface, a primitive type, or void, then
1089 * null is returned. If this {@code Class} object represents an array class
1090 * then the {@code Class} object representing the {@code Object} class is
1091 * returned.
1092 *
1093 * @return the direct superclass of the class represented by this {@code Class} object
1094 */
1095 @IntrinsicCandidate
1096 public native Class<? super T> getSuperclass();
1097
1098
1099 /**
1100 * Returns the {@code Type} representing the direct superclass of
1101 * the entity (class, interface, primitive type or void) represented by
1102 * this {@code Class} object.
1103 *
1104 * <p>If the superclass is a parameterized type, the {@code Type}
1105 * object returned must accurately reflect the actual type
1106 * arguments used in the source code. The parameterized type
1107 * representing the superclass is created if it had not been
1108 * created before. See the declaration of {@link
1109 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1110 * semantics of the creation process for parameterized types. If
1111 * this {@code Class} object represents either the {@code Object}
1112 * class, an interface, a primitive type, or void, then null is
1113 * returned. If this {@code Class} object represents an array class
1114 * then the {@code Class} object representing the {@code Object} class is
1115 * returned.
1116 *
1117 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1118 * class signature does not conform to the format specified in
1119 * section {@jvms 4.7.9} of <cite>The Java Virtual
1120 * Machine Specification</cite>
1121 * @throws TypeNotPresentException if the generic superclass
1122 * refers to a non-existent type declaration
1123 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1124 * generic superclass refers to a parameterized type that cannot be
1125 * instantiated for any reason
1126 * @return the direct superclass of the class represented by this {@code Class} object
1127 * @since 1.5
1128 */
1129 public Type getGenericSuperclass() {
1130 ClassRepository info = getGenericInfo();
1131 if (info == null) {
1132 return getSuperclass();
1133 }
1134
1135 // Historical irregularity:
1136 // Generic signature marks interfaces with superclass = Object
1137 // but this API returns null for interfaces
1138 if (isInterface()) {
1139 return null;
1140 }
1141
1142 return info.getSuperclass();
1143 }
1144
1145 /**
1146 * Gets the package of this class.
1147 *
1148 * <p>If this class represents an array type, a primitive type or void,
1149 * this method returns {@code null}.
1150 *
1151 * @return the package of this class.
1152 */
1153 public Package getPackage() {
1154 if (isPrimitive() || isArray()) {
1155 return null;
1156 }
1157 ClassLoader cl = classLoader;
1158 return cl != null ? cl.definePackage(this)
1159 : BootLoader.definePackage(this);
1160 }
1161
1162 /**
1163 * Returns the fully qualified package name.
1164 *
1165 * <p> If this class is a top level class, then this method returns the fully
1166 * qualified name of the package that the class is a member of, or the
1167 * empty string if the class is in an unnamed package.
1168 *
1169 * <p> If this class is a member class, then this method is equivalent to
1170 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1171 * enclosing class}.
1172 *
1173 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1174 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1175 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1176 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1177 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1178 *
1179 * <p> If this class represents an array type then this method returns the
1180 * package name of the element type. If this class represents a primitive
1181 * type or void then the package name "{@code java.lang}" is returned.
1182 *
1183 * @return the fully qualified package name
1184 *
1185 * @since 9
1186 * @jls 6.7 Fully Qualified Names and Canonical Names
1187 */
1188 public String getPackageName() {
1189 String pn = this.packageName;
1190 if (pn == null) {
1191 Class<?> c = isArray() ? elementType() : this;
1192 if (c.isPrimitive()) {
1193 pn = "java.lang";
1194 } else {
1195 String cn = c.getName();
1196 int dot = cn.lastIndexOf('.');
1197 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1198 }
1199 this.packageName = pn;
1200 }
1201 return pn;
1202 }
1203
1204 // cached package name
1205 private transient String packageName;
1206
1207 /**
1208 * Returns the interfaces directly implemented by the class or interface
1209 * represented by this {@code Class} object.
1210 *
1211 * <p>If this {@code Class} object represents a class, the return value is an array
1212 * containing objects representing all interfaces directly implemented by
1213 * the class. The order of the interface objects in the array corresponds
1214 * to the order of the interface names in the {@code implements} clause of
1215 * the declaration of the class represented by this {@code Class} object. For example,
1216 * given the declaration:
1217 * <blockquote>
1218 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1219 * </blockquote>
1220 * suppose the value of {@code s} is an instance of
1221 * {@code Shimmer}; the value of the expression:
1222 * <blockquote>
1223 * {@code s.getClass().getInterfaces()[0]}
1224 * </blockquote>
1225 * is the {@code Class} object that represents interface
1226 * {@code FloorWax}; and the value of:
1227 * <blockquote>
1228 * {@code s.getClass().getInterfaces()[1]}
1229 * </blockquote>
1230 * is the {@code Class} object that represents interface
1231 * {@code DessertTopping}.
1232 *
1233 * <p>If this {@code Class} object represents an interface, the array contains objects
1234 * representing all interfaces directly extended by the interface. The
1235 * order of the interface objects in the array corresponds to the order of
1236 * the interface names in the {@code extends} clause of the declaration of
1237 * the interface represented by this {@code Class} object.
1238 *
1239 * <p>If this {@code Class} object represents a class or interface that implements no
1240 * interfaces, the method returns an array of length 0.
1241 *
1242 * <p>If this {@code Class} object represents a primitive type or void, the method
1243 * returns an array of length 0.
1244 *
1245 * <p>If this {@code Class} object represents an array type, the
1246 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1247 * returned in that order.
1248 *
1249 * @return an array of interfaces directly implemented by this class
1250 */
1251 public Class<?>[] getInterfaces() {
1252 // defensively copy before handing over to user code
1253 return getInterfaces(true);
1254 }
1255
1256 private Class<?>[] getInterfaces(boolean cloneArray) {
1257 ReflectionData<T> rd = reflectionData();
1258 Class<?>[] interfaces = rd.interfaces;
1259 if (interfaces == null) {
1260 interfaces = getInterfaces0();
1261 rd.interfaces = interfaces;
1262 }
1263 // defensively copy if requested
1264 return cloneArray ? interfaces.clone() : interfaces;
1265 }
1266
1267 private native Class<?>[] getInterfaces0();
1268
1269 /**
1270 * Returns the {@code Type}s representing the interfaces
1271 * directly implemented by the class or interface represented by
1272 * this {@code Class} object.
1273 *
1274 * <p>If a superinterface is a parameterized type, the
1275 * {@code Type} object returned for it must accurately reflect
1276 * the actual type arguments used in the source code. The
1277 * parameterized type representing each superinterface is created
1278 * if it had not been created before. See the declaration of
1279 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1280 * for the semantics of the creation process for parameterized
1281 * types.
1282 *
1283 * <p>If this {@code Class} object represents a class, the return value is an array
1284 * containing objects representing all interfaces directly implemented by
1285 * the class. The order of the interface objects in the array corresponds
1286 * to the order of the interface names in the {@code implements} clause of
1287 * the declaration of the class represented by this {@code Class} object.
1288 *
1289 * <p>If this {@code Class} object represents an interface, the array contains objects
1290 * representing all interfaces directly extended by the interface. The
1291 * order of the interface objects in the array corresponds to the order of
1292 * the interface names in the {@code extends} clause of the declaration of
1293 * the interface represented by this {@code Class} object.
1294 *
1295 * <p>If this {@code Class} object represents a class or interface that implements no
1296 * interfaces, the method returns an array of length 0.
1297 *
1298 * <p>If this {@code Class} object represents a primitive type or void, the method
1299 * returns an array of length 0.
1300 *
1301 * <p>If this {@code Class} object represents an array type, the
1302 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1303 * returned in that order.
1304 *
1305 * @throws java.lang.reflect.GenericSignatureFormatError
1306 * if the generic class signature does not conform to the
1307 * format specified in section {@jvms 4.7.9} of <cite>The
1308 * Java Virtual Machine Specification</cite>
1309 * @throws TypeNotPresentException if any of the generic
1310 * superinterfaces refers to a non-existent type declaration
1311 * @throws java.lang.reflect.MalformedParameterizedTypeException
1312 * if any of the generic superinterfaces refer to a parameterized
1313 * type that cannot be instantiated for any reason
1314 * @return an array of interfaces directly implemented by this class
1315 * @since 1.5
1316 */
1317 public Type[] getGenericInterfaces() {
1318 ClassRepository info = getGenericInfo();
1319 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1320 }
1321
1322
1323 /**
1324 * Returns the {@code Class} representing the component type of an
1325 * array. If this class does not represent an array class this method
1326 * returns null.
1327 *
1328 * @return the {@code Class} representing the component type of this
1329 * class if this class is an array
1330 * @see java.lang.reflect.Array
1331 * @since 1.1
1332 */
1333 public Class<?> getComponentType() {
1334 return componentType;
1335 }
1336
1337 // The componentType field's null value is the sole indication that the class
1338 // is an array - see isArray().
1339 private transient final Class<?> componentType;
1340
1341 /*
1342 * Returns the {@code Class} representing the element type of an array class.
1343 * If this class does not represent an array class, then this method returns
1344 * {@code null}.
1345 */
1346 private Class<?> elementType() {
1347 if (!isArray()) return null;
1348
1349 Class<?> c = this;
1350 while (c.isArray()) {
1351 c = c.getComponentType();
1352 }
1353 return c;
1354 }
1355
1356 /**
1357 * Returns the Java language modifiers for this class or interface, encoded
1358 * in an integer. The modifiers consist of the Java Virtual Machine's
1359 * constants for {@code public}, {@code protected},
1360 * {@code private}, {@code final}, {@code static},
1361 * {@code abstract} and {@code interface}; they should be decoded
1362 * using the methods of class {@code Modifier}.
1363 *
1364 * <p> If the underlying class is an array class:
1365 * <ul>
1366 * <li> its {@code public}, {@code private} and {@code protected}
1367 * modifiers are the same as those of its component type
1368 * <li> its {@code abstract} and {@code final} modifiers are always
1369 * {@code true}
1370 * <li> its interface modifier is always {@code false}, even when
1371 * the component type is an interface
1372 * <li> its {@code identity} modifier is always true
1373 * </ul>
1374 * If this {@code Class} object represents a primitive type or
1375 * void, its {@code public}, {@code abstract}, and {@code final}
1376 * modifiers are always {@code true}.
1377 * For {@code Class} objects representing void, primitive types, and
1378 * arrays, the values of other modifiers are {@code false} other
1379 * than as specified above.
1380 *
1381 * <p> The modifier encodings are defined in section {@jvms 4.1}
1382 * of <cite>The Java Virtual Machine Specification</cite>.
1383 *
1384 * @return the {@code int} representing the modifiers for this class
1385 * @see java.lang.reflect.Modifier
1386 * @see #accessFlags()
1387 * @see <a
1388 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1389 * programming language and JVM modeling in core reflection</a>
1390 * @since 1.1
1391 * @jls 8.1.1 Class Modifiers
1392 * @jls 9.1.1 Interface Modifiers
1393 * @jvms 4.1 The {@code ClassFile} Structure
1394 */
1395 public int getModifiers() { return modifiers; }
1396
1397 /**
1398 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1399 * flags} for this class, possibly empty}
1400 * The {@code AccessFlags} may depend on the class file format version of the class.
1401 *
1402 * <p> If the underlying class is an array class:
1403 * <ul>
1404 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1405 * access flags are the same as those of its component type
1406 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1407 * <li> its {@code INTERFACE} flag is absent, even when the
1408 * component type is an interface
1409 * <li> its {@code identity} modifier is always true
1410 * </ul>
1411 * If this {@code Class} object represents a primitive type or
1412 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1413 * {@code FINAL}.
1414 * For {@code Class} objects representing void, primitive types, and
1415 * arrays, access flags are absent other than as specified above.
1416 *
1417 * @see #getModifiers()
1418 * @jvms 4.1 The ClassFile Structure
1419 * @jvms 4.7.6 The InnerClasses Attribute
1420 * @since 20
1421 */
1422 public Set<AccessFlag> accessFlags() {
1423 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1424 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1425 // and STATIC, which are not allowed on Location.CLASS.
1426 // Use getClassAccessFlagsRaw to expose SUPER status.
1427 var location = (isMemberClass() || isLocalClass() ||
1428 isAnonymousClass() || isArray()) ?
1429 AccessFlag.Location.INNER_CLASS :
1430 AccessFlag.Location.CLASS;
1431 int accessFlags = (location == AccessFlag.Location.CLASS) ?
1432 getClassAccessFlagsRaw() : getModifiers();
1433 if (isArray() && PreviewFeatures.isEnabled()) {
1434 accessFlags |= Modifier.IDENTITY;
1435 }
1436 var cffv = ClassFileFormatVersion.fromMajor(getClassFileVersion() & 0xffff);
1437 if (cffv.compareTo(ClassFileFormatVersion.latest()) >= 0) {
1438 // Ignore unspecified (0x0800) access flag for current version
1439 accessFlags &= ~0x0800;
1440 }
1441 return AccessFlag.maskToAccessFlags(accessFlags, location, cffv);
1442 }
1443
1444 /**
1445 * Gets the signers of this class.
1446 *
1447 * @return the signers of this class, or null if there are no signers. In
1448 * particular, this method returns null if this {@code Class} object represents
1449 * a primitive type or void.
1450 * @since 1.1
1451 */
1452
1453 public Object[] getSigners() {
1454 var signers = this.signers;
1455 return signers == null ? null : signers.clone();
1456 }
1457
1458 /**
1459 * Set the signers of this class.
1460 */
1461 void setSigners(Object[] signers) {
1462 if (!isPrimitive() && !isArray()) {
1463 this.signers = signers;
1464 }
1465 }
1466
1467 /**
1468 * If this {@code Class} object represents a local or anonymous
1469 * class within a method, returns a {@link
1470 * java.lang.reflect.Method Method} object representing the
1471 * immediately enclosing method of the underlying class. Returns
1472 * {@code null} otherwise.
1473 *
1474 * In particular, this method returns {@code null} if the underlying
1475 * class is a local or anonymous class immediately enclosed by a class or
1476 * interface declaration, instance initializer or static initializer.
1477 *
1478 * @return the immediately enclosing method of the underlying class, if
1479 * that class is a local or anonymous class; otherwise {@code null}.
1480 *
1481 * @since 1.5
1482 */
1483 public Method getEnclosingMethod() {
1484 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1485
1486 if (enclosingInfo == null)
1487 return null;
1488 else {
1489 if (!enclosingInfo.isMethod())
1490 return null;
1491
1492 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1493 getFactory());
1494 Class<?> returnType = toClass(typeInfo.getReturnType());
1495 Type [] parameterTypes = typeInfo.getParameterTypes();
1496 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1497
1498 // Convert Types to Classes; returned types *should*
1499 // be class objects since the methodDescriptor's used
1500 // don't have generics information
1501 for(int i = 0; i < parameterClasses.length; i++)
1502 parameterClasses[i] = toClass(parameterTypes[i]);
1503
1504 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1505 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1506
1507 /*
1508 * Loop over all declared methods; match method name,
1509 * number of and type of parameters, *and* return
1510 * type. Matching return type is also necessary
1511 * because of covariant returns, etc.
1512 */
1513 ReflectionFactory fact = getReflectionFactory();
1514 for (Method m : candidates) {
1515 if (m.getName().equals(enclosingInfo.getName()) &&
1516 arrayContentsEq(parameterClasses,
1517 fact.getExecutableSharedParameterTypes(m))) {
1518 // finally, check return type
1519 if (m.getReturnType().equals(returnType)) {
1520 return fact.copyMethod(m);
1521 }
1522 }
1523 }
1524
1525 throw new InternalError("Enclosing method not found");
1526 }
1527 }
1528
1529 private native Object[] getEnclosingMethod0();
1530
1531 private EnclosingMethodInfo getEnclosingMethodInfo() {
1532 Object[] enclosingInfo = getEnclosingMethod0();
1533 if (enclosingInfo == null)
1534 return null;
1535 else {
1536 return new EnclosingMethodInfo(enclosingInfo);
1537 }
1538 }
1539
1540 private static final class EnclosingMethodInfo {
1541 private final Class<?> enclosingClass;
1542 private final String name;
1543 private final String descriptor;
1544
1545 static void validate(Object[] enclosingInfo) {
1546 if (enclosingInfo.length != 3)
1547 throw new InternalError("Malformed enclosing method information");
1548 try {
1549 // The array is expected to have three elements:
1550
1551 // the immediately enclosing class
1552 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1553 assert(enclosingClass != null);
1554
1555 // the immediately enclosing method or constructor's
1556 // name (can be null).
1557 String name = (String)enclosingInfo[1];
1558
1559 // the immediately enclosing method or constructor's
1560 // descriptor (null iff name is).
1561 String descriptor = (String)enclosingInfo[2];
1562 assert((name != null && descriptor != null) || name == descriptor);
1563 } catch (ClassCastException cce) {
1564 throw new InternalError("Invalid type in enclosing method information", cce);
1565 }
1566 }
1567
1568 EnclosingMethodInfo(Object[] enclosingInfo) {
1569 validate(enclosingInfo);
1570 this.enclosingClass = (Class<?>)enclosingInfo[0];
1571 this.name = (String)enclosingInfo[1];
1572 this.descriptor = (String)enclosingInfo[2];
1573 }
1574
1575 boolean isPartial() {
1576 return enclosingClass == null || name == null || descriptor == null;
1577 }
1578
1579 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1580
1581 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1582
1583 Class<?> getEnclosingClass() { return enclosingClass; }
1584
1585 String getName() { return name; }
1586
1587 String getDescriptor() { return descriptor; }
1588
1589 }
1590
1591 private static Class<?> toClass(Type o) {
1592 if (o instanceof GenericArrayType gat)
1593 return toClass(gat.getGenericComponentType()).arrayType();
1594 return (Class<?>)o;
1595 }
1596
1597 /**
1598 * If this {@code Class} object represents a local or anonymous
1599 * class within a constructor, returns a {@link
1600 * java.lang.reflect.Constructor Constructor} object representing
1601 * the immediately enclosing constructor of the underlying
1602 * class. Returns {@code null} otherwise. In particular, this
1603 * method returns {@code null} if the underlying class is a local
1604 * or anonymous class immediately enclosed by a class or
1605 * interface declaration, instance initializer or static initializer.
1606 *
1607 * @return the immediately enclosing constructor of the underlying class, if
1608 * that class is a local or anonymous class; otherwise {@code null}.
1609 *
1610 * @since 1.5
1611 */
1612 public Constructor<?> getEnclosingConstructor() {
1613 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1614
1615 if (enclosingInfo == null)
1616 return null;
1617 else {
1618 if (!enclosingInfo.isConstructor())
1619 return null;
1620
1621 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1622 getFactory());
1623 Type [] parameterTypes = typeInfo.getParameterTypes();
1624 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1625
1626 // Convert Types to Classes; returned types *should*
1627 // be class objects since the methodDescriptor's used
1628 // don't have generics information
1629 for (int i = 0; i < parameterClasses.length; i++)
1630 parameterClasses[i] = toClass(parameterTypes[i]);
1631
1632
1633 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1634 Constructor<?>[] candidates = enclosingCandidate
1635 .privateGetDeclaredConstructors(false);
1636 /*
1637 * Loop over all declared constructors; match number
1638 * of and type of parameters.
1639 */
1640 ReflectionFactory fact = getReflectionFactory();
1641 for (Constructor<?> c : candidates) {
1642 if (arrayContentsEq(parameterClasses,
1643 fact.getExecutableSharedParameterTypes(c))) {
1644 return fact.copyConstructor(c);
1645 }
1646 }
1647
1648 throw new InternalError("Enclosing constructor not found");
1649 }
1650 }
1651
1652
1653 /**
1654 * If the class or interface represented by this {@code Class} object
1655 * is a member of another class, returns the {@code Class} object
1656 * representing the class in which it was declared. This method returns
1657 * null if this class or interface is not a member of any other class. If
1658 * this {@code Class} object represents an array class, a primitive
1659 * type, or void, then this method returns null.
1660 *
1661 * @return the declaring class for this class
1662 * @since 1.1
1663 */
1664 public Class<?> getDeclaringClass() {
1665 return getDeclaringClass0();
1666 }
1667
1668 private native Class<?> getDeclaringClass0();
1669
1670
1671 /**
1672 * Returns the immediately enclosing class of the underlying
1673 * class. If the underlying class is a top level class this
1674 * method returns {@code null}.
1675 * @return the immediately enclosing class of the underlying class
1676 * @since 1.5
1677 */
1678 public Class<?> getEnclosingClass() {
1679 // There are five kinds of classes (or interfaces):
1680 // a) Top level classes
1681 // b) Nested classes (static member classes)
1682 // c) Inner classes (non-static member classes)
1683 // d) Local classes (named classes declared within a method)
1684 // e) Anonymous classes
1685
1686
1687 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1688 // attribute if and only if it is a local class or an
1689 // anonymous class.
1690 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1691 Class<?> enclosingCandidate;
1692
1693 if (enclosingInfo == null) {
1694 // This is a top level or a nested class or an inner class (a, b, or c)
1695 enclosingCandidate = getDeclaringClass0();
1696 } else {
1697 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1698 // This is a local class or an anonymous class (d or e)
1699 if (enclosingClass == this || enclosingClass == null)
1700 throw new InternalError("Malformed enclosing method information");
1701 else
1702 enclosingCandidate = enclosingClass;
1703 }
1704 return enclosingCandidate;
1705 }
1706
1707 /**
1708 * Returns the simple name of the underlying class as given in the
1709 * source code. An empty string is returned if the underlying class is
1710 * {@linkplain #isAnonymousClass() anonymous}.
1711 * A {@linkplain #isSynthetic() synthetic class}, one not present
1712 * in source code, can have a non-empty name including special
1713 * characters, such as "{@code $}".
1714 *
1715 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1716 * component type with "[]" appended. In particular the simple
1717 * name of an array class whose component type is anonymous is "[]".
1718 *
1719 * @return the simple name of the underlying class
1720 * @since 1.5
1721 */
1722 public String getSimpleName() {
1723 ReflectionData<T> rd = reflectionData();
1724 String simpleName = rd.simpleName;
1725 if (simpleName == null) {
1726 rd.simpleName = simpleName = getSimpleName0();
1727 }
1728 return simpleName;
1729 }
1730
1731 private String getSimpleName0() {
1732 if (isArray()) {
1733 return getComponentType().getSimpleName().concat("[]");
1734 }
1735 String simpleName = getSimpleBinaryName();
1736 if (simpleName == null) { // top level class
1737 simpleName = getName();
1738 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1739 }
1740 return simpleName;
1741 }
1742
1743 /**
1744 * Return an informative string for the name of this class or interface.
1745 *
1746 * @return an informative string for the name of this class or interface
1747 * @since 1.8
1748 */
1749 public String getTypeName() {
1750 if (isArray()) {
1751 try {
1752 Class<?> cl = this;
1753 int dimensions = 0;
1754 do {
1755 dimensions++;
1756 cl = cl.getComponentType();
1757 } while (cl.isArray());
1758 return cl.getName().concat("[]".repeat(dimensions));
1759 } catch (Throwable e) { /*FALLTHRU*/ }
1760 }
1761 return getName();
1762 }
1763
1764 /**
1765 * Returns the canonical name of the underlying class as
1766 * defined by <cite>The Java Language Specification</cite>.
1767 * Returns {@code null} if the underlying class does not have a canonical
1768 * name. Classes without canonical names include:
1769 * <ul>
1770 * <li>a {@linkplain #isLocalClass() local class}
1771 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1772 * <li>a {@linkplain #isHidden() hidden class}
1773 * <li>an array whose component type does not have a canonical name</li>
1774 * </ul>
1775 *
1776 * The canonical name for a primitive class is the keyword for the
1777 * corresponding primitive type ({@code byte}, {@code short},
1778 * {@code char}, {@code int}, and so on).
1779 *
1780 * <p>An array type has a canonical name if and only if its
1781 * component type has a canonical name. When an array type has a
1782 * canonical name, it is equal to the canonical name of the
1783 * component type followed by "{@code []}".
1784 *
1785 * @return the canonical name of the underlying class if it exists, and
1786 * {@code null} otherwise.
1787 * @jls 6.7 Fully Qualified Names and Canonical Names
1788 * @since 1.5
1789 */
1790 public String getCanonicalName() {
1791 ReflectionData<T> rd = reflectionData();
1792 String canonicalName = rd.canonicalName;
1793 if (canonicalName == null) {
1794 rd.canonicalName = canonicalName = getCanonicalName0();
1795 }
1796 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1797 }
1798
1799 private String getCanonicalName0() {
1800 if (isArray()) {
1801 String canonicalName = getComponentType().getCanonicalName();
1802 if (canonicalName != null)
1803 return canonicalName.concat("[]");
1804 else
1805 return ReflectionData.NULL_SENTINEL;
1806 }
1807 if (isHidden() || isLocalOrAnonymousClass())
1808 return ReflectionData.NULL_SENTINEL;
1809 Class<?> enclosingClass = getEnclosingClass();
1810 if (enclosingClass == null) { // top level class
1811 return getName();
1812 } else {
1813 String enclosingName = enclosingClass.getCanonicalName();
1814 if (enclosingName == null)
1815 return ReflectionData.NULL_SENTINEL;
1816 String simpleName = getSimpleName();
1817 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1818 .append(enclosingName)
1819 .append('.')
1820 .append(simpleName)
1821 .toString();
1822 }
1823 }
1824
1825 /**
1826 * Returns {@code true} if and only if the underlying class
1827 * is an anonymous class.
1828 *
1829 * @apiNote
1830 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1831 *
1832 * @return {@code true} if and only if this class is an anonymous class.
1833 * @since 1.5
1834 * @jls 15.9.5 Anonymous Class Declarations
1835 */
1836 public boolean isAnonymousClass() {
1837 return !isArray() && isLocalOrAnonymousClass() &&
1838 getSimpleBinaryName0() == null;
1839 }
1840
1841 /**
1842 * Returns {@code true} if and only if the underlying class
1843 * is a local class.
1844 *
1845 * @return {@code true} if and only if this class is a local class.
1846 * @since 1.5
1847 * @jls 14.3 Local Class and Interface Declarations
1848 */
1849 public boolean isLocalClass() {
1850 return isLocalOrAnonymousClass() &&
1851 (isArray() || getSimpleBinaryName0() != null);
1852 }
1853
1854 /**
1855 * Returns {@code true} if and only if the underlying class
1856 * is a member class.
1857 *
1858 * @return {@code true} if and only if this class is a member class.
1859 * @since 1.5
1860 * @jls 8.5 Member Class and Interface Declarations
1861 */
1862 public boolean isMemberClass() {
1863 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1864 }
1865
1866 /**
1867 * Returns the "simple binary name" of the underlying class, i.e.,
1868 * the binary name without the leading enclosing class name.
1869 * Returns {@code null} if the underlying class is a top level
1870 * class.
1871 */
1872 private String getSimpleBinaryName() {
1873 if (isTopLevelClass())
1874 return null;
1875 String name = getSimpleBinaryName0();
1876 if (name == null) // anonymous class
1877 return "";
1878 return name;
1879 }
1880
1881 private native String getSimpleBinaryName0();
1882
1883 /**
1884 * Returns {@code true} if this is a top level class. Returns {@code false}
1885 * otherwise.
1886 */
1887 private boolean isTopLevelClass() {
1888 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1889 }
1890
1891 /**
1892 * Returns {@code true} if this is a local class or an anonymous
1893 * class. Returns {@code false} otherwise.
1894 */
1895 private boolean isLocalOrAnonymousClass() {
1896 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1897 // attribute if and only if it is a local class or an
1898 // anonymous class.
1899 return hasEnclosingMethodInfo();
1900 }
1901
1902 private boolean hasEnclosingMethodInfo() {
1903 Object[] enclosingInfo = getEnclosingMethod0();
1904 if (enclosingInfo != null) {
1905 EnclosingMethodInfo.validate(enclosingInfo);
1906 return true;
1907 }
1908 return false;
1909 }
1910
1911 /**
1912 * Returns an array containing {@code Class} objects representing all
1913 * the public classes and interfaces that are members of the class
1914 * represented by this {@code Class} object. This includes public
1915 * class and interface members inherited from superclasses and public class
1916 * and interface members declared by the class. This method returns an
1917 * array of length 0 if this {@code Class} object has no public member
1918 * classes or interfaces. This method also returns an array of length 0 if
1919 * this {@code Class} object represents a primitive type, an array
1920 * class, or void.
1921 *
1922 * @return the array of {@code Class} objects representing the public
1923 * members of this class
1924 * @since 1.1
1925 */
1926 public Class<?>[] getClasses() {
1927 List<Class<?>> list = new ArrayList<>();
1928 Class<?> currentClass = Class.this;
1929 while (currentClass != null) {
1930 for (Class<?> m : currentClass.getDeclaredClasses()) {
1931 if (Modifier.isPublic(m.getModifiers())) {
1932 list.add(m);
1933 }
1934 }
1935 currentClass = currentClass.getSuperclass();
1936 }
1937 return list.toArray(new Class<?>[0]);
1938 }
1939
1940
1941 /**
1942 * Returns an array containing {@code Field} objects reflecting all
1943 * the accessible public fields of the class or interface represented by
1944 * this {@code Class} object.
1945 *
1946 * <p> If this {@code Class} object represents a class or interface with
1947 * no accessible public fields, then this method returns an array of length
1948 * 0.
1949 *
1950 * <p> If this {@code Class} object represents a class, then this method
1951 * returns the public fields of the class and of all its superclasses and
1952 * superinterfaces.
1953 *
1954 * <p> If this {@code Class} object represents an interface, then this
1955 * method returns the fields of the interface and of all its
1956 * superinterfaces.
1957 *
1958 * <p> If this {@code Class} object represents an array type, a primitive
1959 * type, or void, then this method returns an array of length 0.
1960 *
1961 * <p> The elements in the returned array are not sorted and are not in any
1962 * particular order.
1963 *
1964 * @return the array of {@code Field} objects representing the
1965 * public fields
1966 *
1967 * @since 1.1
1968 * @jls 8.2 Class Members
1969 * @jls 8.3 Field Declarations
1970 */
1971 public Field[] getFields() {
1972 return copyFields(privateGetPublicFields());
1973 }
1974
1975
1976 /**
1977 * Returns an array containing {@code Method} objects reflecting all the
1978 * public methods of the class or interface represented by this {@code
1979 * Class} object, including those declared by the class or interface and
1980 * those inherited from superclasses and superinterfaces.
1981 *
1982 * <p> If this {@code Class} object represents an array type, then the
1983 * returned array has a {@code Method} object for each of the public
1984 * methods inherited by the array type from {@code Object}. It does not
1985 * contain a {@code Method} object for {@code clone()}.
1986 *
1987 * <p> If this {@code Class} object represents an interface then the
1988 * returned array does not contain any implicitly declared methods from
1989 * {@code Object}. Therefore, if no methods are explicitly declared in
1990 * this interface or any of its superinterfaces then the returned array
1991 * has length 0. (Note that a {@code Class} object which represents a class
1992 * always has public methods, inherited from {@code Object}.)
1993 *
1994 * <p> The returned array never contains methods with names {@value
1995 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1996 *
1997 * <p> The elements in the returned array are not sorted and are not in any
1998 * particular order.
1999 *
2000 * <p> Generally, the result is computed as with the following 4 step algorithm.
2001 * Let C be the class or interface represented by this {@code Class} object:
2002 * <ol>
2003 * <li> A union of methods is composed of:
2004 * <ol type="a">
2005 * <li> C's declared public instance and static methods as returned by
2006 * {@link #getDeclaredMethods()} and filtered to include only public
2007 * methods.</li>
2008 * <li> If C is a class other than {@code Object}, then include the result
2009 * of invoking this algorithm recursively on the superclass of C.</li>
2010 * <li> Include the results of invoking this algorithm recursively on all
2011 * direct superinterfaces of C, but include only instance methods.</li>
2012 * </ol></li>
2013 * <li> Union from step 1 is partitioned into subsets of methods with same
2014 * signature (name, parameter types) and return type.</li>
2015 * <li> Within each such subset only the most specific methods are selected.
2016 * Let method M be a method from a set of methods with same signature
2017 * and return type. M is most specific if there is no such method
2018 * N != M from the same set, such that N is more specific than M.
2019 * N is more specific than M if:
2020 * <ol type="a">
2021 * <li> N is declared by a class and M is declared by an interface; or</li>
2022 * <li> N and M are both declared by classes or both by interfaces and
2023 * N's declaring type is the same as or a subtype of M's declaring type
2024 * (clearly, if M's and N's declaring types are the same type, then
2025 * M and N are the same method).</li>
2026 * </ol></li>
2027 * <li> The result of this algorithm is the union of all selected methods from
2028 * step 3.</li>
2029 * </ol>
2030 *
2031 * @apiNote There may be more than one method with a particular name
2032 * and parameter types in a class because while the Java language forbids a
2033 * class to declare multiple methods with the same signature but different
2034 * return types, the Java virtual machine does not. This
2035 * increased flexibility in the virtual machine can be used to
2036 * implement various language features. For example, covariant
2037 * returns can be implemented with {@linkplain
2038 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2039 * method and the overriding method would have the same
2040 * signature but different return types.
2041 *
2042 * @return the array of {@code Method} objects representing the
2043 * public methods of this class
2044 *
2045 * @jls 8.2 Class Members
2046 * @jls 8.4 Method Declarations
2047 * @since 1.1
2048 */
2049 public Method[] getMethods() {
2050 return copyMethods(privateGetPublicMethods());
2051 }
2052
2053
2054 /**
2055 * Returns an array containing {@code Constructor} objects reflecting
2056 * all the public constructors of the class represented by this
2057 * {@code Class} object. An array of length 0 is returned if the
2058 * class has no public constructors, or if the class is an array class, or
2059 * if the class reflects a primitive type or void.
2060 *
2061 * @apiNote
2062 * While this method returns an array of {@code
2063 * Constructor<T>} objects (that is an array of constructors from
2064 * this class), the return type of this method is {@code
2065 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2066 * might be expected. This less informative return type is
2067 * necessary since after being returned from this method, the
2068 * array could be modified to hold {@code Constructor} objects for
2069 * different classes, which would violate the type guarantees of
2070 * {@code Constructor<T>[]}.
2071 *
2072 * @return the array of {@code Constructor} objects representing the
2073 * public constructors of this class
2074 *
2075 * @see #getDeclaredConstructors()
2076 * @since 1.1
2077 */
2078 public Constructor<?>[] getConstructors() {
2079 return copyConstructors(privateGetDeclaredConstructors(true));
2080 }
2081
2082
2083 /**
2084 * Returns a {@code Field} object that reflects the specified public member
2085 * field of the class or interface represented by this {@code Class}
2086 * object. The {@code name} parameter is a {@code String} specifying the
2087 * simple name of the desired field.
2088 *
2089 * <p> The field to be reflected is determined by the algorithm that
2090 * follows. Let C be the class or interface represented by this {@code Class} object:
2091 *
2092 * <OL>
2093 * <LI> If C declares a public field with the name specified, that is the
2094 * field to be reflected.</LI>
2095 * <LI> If no field was found in step 1 above, this algorithm is applied
2096 * recursively to each direct superinterface of C. The direct
2097 * superinterfaces are searched in the order they were declared.</LI>
2098 * <LI> If no field was found in steps 1 and 2 above, and C has a
2099 * superclass S, then this algorithm is invoked recursively upon S.
2100 * If C has no superclass, then a {@code NoSuchFieldException}
2101 * is thrown.</LI>
2102 * </OL>
2103 *
2104 * <p> If this {@code Class} object represents an array type, then this
2105 * method does not find the {@code length} field of the array type.
2106 *
2107 * @param name the field name
2108 * @return the {@code Field} object of this class specified by
2109 * {@code name}
2110 * @throws NoSuchFieldException if a field with the specified name is
2111 * not found.
2112 * @throws NullPointerException if {@code name} is {@code null}
2113 *
2114 * @since 1.1
2115 * @jls 8.2 Class Members
2116 * @jls 8.3 Field Declarations
2117 */
2118 public Field getField(String name) throws NoSuchFieldException {
2119 Objects.requireNonNull(name);
2120 Field field = getField0(name);
2121 if (field == null) {
2122 throw new NoSuchFieldException(name);
2123 }
2124 return getReflectionFactory().copyField(field);
2125 }
2126
2127
2128 /**
2129 * Returns a {@code Method} object that reflects the specified public
2130 * member method of the class or interface represented by this
2131 * {@code Class} object. The {@code name} parameter is a
2132 * {@code String} specifying the simple name of the desired method. The
2133 * {@code parameterTypes} parameter is an array of {@code Class}
2134 * objects that identify the method's formal parameter types, in declared
2135 * order. If {@code parameterTypes} is {@code null}, it is
2136 * treated as if it were an empty array.
2137 *
2138 * <p> If this {@code Class} object represents an array type, then this
2139 * method finds any public method inherited by the array type from
2140 * {@code Object} except method {@code clone()}.
2141 *
2142 * <p> If this {@code Class} object represents an interface then this
2143 * method does not find any implicitly declared method from
2144 * {@code Object}. Therefore, if no methods are explicitly declared in
2145 * this interface or any of its superinterfaces, then this method does not
2146 * find any method.
2147 *
2148 * <p> This method does not find any method with name {@value
2149 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2150 *
2151 * <p> Generally, the method to be reflected is determined by the 4 step
2152 * algorithm that follows.
2153 * Let C be the class or interface represented by this {@code Class} object:
2154 * <ol>
2155 * <li> A union of methods is composed of:
2156 * <ol type="a">
2157 * <li> C's declared public instance and static methods as returned by
2158 * {@link #getDeclaredMethods()} and filtered to include only public
2159 * methods that match given {@code name} and {@code parameterTypes}</li>
2160 * <li> If C is a class other than {@code Object}, then include the result
2161 * of invoking this algorithm recursively on the superclass of C.</li>
2162 * <li> Include the results of invoking this algorithm recursively on all
2163 * direct superinterfaces of C, but include only instance methods.</li>
2164 * </ol></li>
2165 * <li> This union is partitioned into subsets of methods with same
2166 * return type (the selection of methods from step 1 also guarantees that
2167 * they have the same method name and parameter types).</li>
2168 * <li> Within each such subset only the most specific methods are selected.
2169 * Let method M be a method from a set of methods with same VM
2170 * signature (return type, name, parameter types).
2171 * M is most specific if there is no such method N != M from the same
2172 * set, such that N is more specific than M. N is more specific than M
2173 * if:
2174 * <ol type="a">
2175 * <li> N is declared by a class and M is declared by an interface; or</li>
2176 * <li> N and M are both declared by classes or both by interfaces and
2177 * N's declaring type is the same as or a subtype of M's declaring type
2178 * (clearly, if M's and N's declaring types are the same type, then
2179 * M and N are the same method).</li>
2180 * </ol></li>
2181 * <li> The result of this algorithm is chosen arbitrarily from the methods
2182 * with most specific return type among all selected methods from step 3.
2183 * Let R be a return type of a method M from the set of all selected methods
2184 * from step 3. M is a method with most specific return type if there is
2185 * no such method N != M from the same set, having return type S != R,
2186 * such that S is a subtype of R as determined by
2187 * R.class.{@link #isAssignableFrom}(S.class).
2188 * </ol>
2189 *
2190 * @apiNote There may be more than one method with matching name and
2191 * parameter types in a class because while the Java language forbids a
2192 * class to declare multiple methods with the same signature but different
2193 * return types, the Java virtual machine does not. This
2194 * increased flexibility in the virtual machine can be used to
2195 * implement various language features. For example, covariant
2196 * returns can be implemented with {@linkplain
2197 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2198 * method and the overriding method would have the same
2199 * signature but different return types. This method would return the
2200 * overriding method as it would have a more specific return type.
2201 *
2202 * @param name the name of the method
2203 * @param parameterTypes the list of parameters
2204 * @return the {@code Method} object that matches the specified
2205 * {@code name} and {@code parameterTypes}
2206 * @throws NoSuchMethodException if a matching method is not found
2207 * or if the name is {@value ConstantDescs#INIT_NAME} or
2208 * {@value ConstantDescs#CLASS_INIT_NAME}.
2209 * @throws NullPointerException if {@code name} is {@code null}
2210 *
2211 * @jls 8.2 Class Members
2212 * @jls 8.4 Method Declarations
2213 * @since 1.1
2214 */
2215 public Method getMethod(String name, Class<?>... parameterTypes)
2216 throws NoSuchMethodException {
2217 Objects.requireNonNull(name);
2218 Method method = getMethod0(name, parameterTypes);
2219 if (method == null) {
2220 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2221 }
2222 return getReflectionFactory().copyMethod(method);
2223 }
2224
2225 /**
2226 * Returns a {@code Constructor} object that reflects the specified
2227 * public constructor of the class represented by this {@code Class}
2228 * object. The {@code parameterTypes} parameter is an array of
2229 * {@code Class} objects that identify the constructor's formal
2230 * parameter types, in declared order.
2231 *
2232 * If this {@code Class} object represents an inner class
2233 * declared in a non-static context, the formal parameter types
2234 * include the explicit enclosing instance as the first parameter.
2235 *
2236 * <p> The constructor to reflect is the public constructor of the class
2237 * represented by this {@code Class} object whose formal parameter
2238 * types match those specified by {@code parameterTypes}.
2239 *
2240 * @param parameterTypes the parameter array
2241 * @return the {@code Constructor} object of the public constructor that
2242 * matches the specified {@code parameterTypes}
2243 * @throws NoSuchMethodException if a matching constructor is not found,
2244 * including when this {@code Class} object represents
2245 * an interface, a primitive type, an array class, or void.
2246 *
2247 * @see #getDeclaredConstructor(Class[])
2248 * @since 1.1
2249 */
2250 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2251 throws NoSuchMethodException {
2252 return getReflectionFactory().copyConstructor(
2253 getConstructor0(parameterTypes, Member.PUBLIC));
2254 }
2255
2256
2257 /**
2258 * Returns an array of {@code Class} objects reflecting all the
2259 * classes and interfaces declared as members of the class represented by
2260 * this {@code Class} object. This includes public, protected, default
2261 * (package) access, and private classes and interfaces declared by the
2262 * class, but excludes inherited classes and interfaces. This method
2263 * returns an array of length 0 if the class declares no classes or
2264 * interfaces as members, or if this {@code Class} object represents a
2265 * primitive type, an array class, or void.
2266 *
2267 * @return the array of {@code Class} objects representing all the
2268 * declared members of this class
2269 *
2270 * @since 1.1
2271 * @jls 8.5 Member Class and Interface Declarations
2272 */
2273 public Class<?>[] getDeclaredClasses() {
2274 return getDeclaredClasses0();
2275 }
2276
2277
2278 /**
2279 * Returns an array of {@code Field} objects reflecting all the fields
2280 * declared by the class or interface represented by this
2281 * {@code Class} object. This includes public, protected, default
2282 * (package) access, and private fields, but excludes inherited fields.
2283 *
2284 * <p> If this {@code Class} object represents a class or interface with no
2285 * declared fields, then this method returns an array of length 0.
2286 *
2287 * <p> If this {@code Class} object represents an array type, a primitive
2288 * type, or void, then this method returns an array of length 0.
2289 *
2290 * <p> The elements in the returned array are not sorted and are not in any
2291 * particular order.
2292 *
2293 * @return the array of {@code Field} objects representing all the
2294 * declared fields of this class
2295 *
2296 * @since 1.1
2297 * @jls 8.2 Class Members
2298 * @jls 8.3 Field Declarations
2299 */
2300 public Field[] getDeclaredFields() {
2301 return copyFields(privateGetDeclaredFields(false));
2302 }
2303
2304 /**
2305 * Returns an array of {@code RecordComponent} objects representing all the
2306 * record components of this record class, or {@code null} if this class is
2307 * not a record class.
2308 *
2309 * <p> The components are returned in the same order that they are declared
2310 * in the record header. The array is empty if this record class has no
2311 * components. If the class is not a record class, that is {@link
2312 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2313 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2314 * returns a non-null value.
2315 *
2316 * @apiNote
2317 * <p> The following method can be used to find the record canonical constructor:
2318 *
2319 * {@snippet lang="java" :
2320 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2321 * throws NoSuchMethodException {
2322 * Class<?>[] paramTypes =
2323 * Arrays.stream(cls.getRecordComponents())
2324 * .map(RecordComponent::getType)
2325 * .toArray(Class<?>[]::new);
2326 * return cls.getDeclaredConstructor(paramTypes);
2327 * }}
2328 *
2329 * @return An array of {@code RecordComponent} objects representing all the
2330 * record components of this record class, or {@code null} if this
2331 * class is not a record class
2332 *
2333 * @jls 8.10 Record Classes
2334 * @since 16
2335 */
2336 public RecordComponent[] getRecordComponents() {
2337 if (!isRecord()) {
2338 return null;
2339 }
2340 return getRecordComponents0();
2341 }
2342
2343 /**
2344 * Returns an array containing {@code Method} objects reflecting all the
2345 * declared methods of the class or interface represented by this {@code
2346 * Class} object, including public, protected, default (package)
2347 * access, and private methods, but excluding inherited methods.
2348 * The declared methods may include methods <em>not</em> in the
2349 * source of the class or interface, including {@linkplain
2350 * Method#isBridge bridge methods} and other {@linkplain
2351 * Executable#isSynthetic synthetic} methods added by compilers.
2352 *
2353 * <p> If this {@code Class} object represents a class or interface that
2354 * has multiple declared methods with the same name and parameter types,
2355 * but different return types, then the returned array has a {@code Method}
2356 * object for each such method.
2357 *
2358 * <p> If this {@code Class} object represents a class or interface that
2359 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2360 * then the returned array does <em>not</em> have a corresponding {@code
2361 * Method} object.
2362 *
2363 * <p> If this {@code Class} object represents a class or interface with no
2364 * declared methods, then the returned array has length 0.
2365 *
2366 * <p> If this {@code Class} object represents an array type, a primitive
2367 * type, or void, then the returned array has length 0.
2368 *
2369 * <p> The elements in the returned array are not sorted and are not in any
2370 * particular order.
2371 *
2372 * @return the array of {@code Method} objects representing all the
2373 * declared methods of this class
2374 *
2375 * @jls 8.2 Class Members
2376 * @jls 8.4 Method Declarations
2377 * @see <a
2378 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2379 * programming language and JVM modeling in core reflection</a>
2380 * @since 1.1
2381 */
2382 public Method[] getDeclaredMethods() {
2383 return copyMethods(privateGetDeclaredMethods(false));
2384 }
2385
2386 /**
2387 * Returns an array of {@code Constructor} objects reflecting all the
2388 * constructors implicitly or explicitly declared by the class represented by this
2389 * {@code Class} object. These are public, protected, default
2390 * (package) access, and private constructors. The elements in the array
2391 * returned are not sorted and are not in any particular order. If the
2392 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2393 * If a record class has a canonical constructor (JLS {@jls
2394 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2395 *
2396 * This method returns an array of length 0 if this {@code Class}
2397 * object represents an interface, a primitive type, an array class, or
2398 * void.
2399 *
2400 * @return the array of {@code Constructor} objects representing all the
2401 * declared constructors of this class
2402 *
2403 * @since 1.1
2404 * @see #getConstructors()
2405 * @jls 8.8 Constructor Declarations
2406 */
2407 public Constructor<?>[] getDeclaredConstructors() {
2408 return copyConstructors(privateGetDeclaredConstructors(false));
2409 }
2410
2411
2412 /**
2413 * Returns a {@code Field} object that reflects the specified declared
2414 * field of the class or interface represented by this {@code Class}
2415 * object. The {@code name} parameter is a {@code String} that specifies
2416 * the simple name of the desired field.
2417 *
2418 * <p> If this {@code Class} object represents an array type, then this
2419 * method does not find the {@code length} field of the array type.
2420 *
2421 * @param name the name of the field
2422 * @return the {@code Field} object for the specified field in this
2423 * class
2424 * @throws NoSuchFieldException if a field with the specified name is
2425 * not found.
2426 * @throws NullPointerException if {@code name} is {@code null}
2427 *
2428 * @since 1.1
2429 * @jls 8.2 Class Members
2430 * @jls 8.3 Field Declarations
2431 */
2432 public Field getDeclaredField(String name) throws NoSuchFieldException {
2433 Objects.requireNonNull(name);
2434 Field field = searchFields(privateGetDeclaredFields(false), name);
2435 if (field == null) {
2436 throw new NoSuchFieldException(name);
2437 }
2438 return getReflectionFactory().copyField(field);
2439 }
2440
2441
2442 /**
2443 * Returns a {@code Method} object that reflects the specified
2444 * declared method of the class or interface represented by this
2445 * {@code Class} object. The {@code name} parameter is a
2446 * {@code String} that specifies the simple name of the desired
2447 * method, and the {@code parameterTypes} parameter is an array of
2448 * {@code Class} objects that identify the method's formal parameter
2449 * types, in declared order. If more than one method with the same
2450 * parameter types is declared in a class, and one of these methods has a
2451 * return type that is more specific than any of the others, that method is
2452 * returned; otherwise one of the methods is chosen arbitrarily. If the
2453 * name is {@value ConstantDescs#INIT_NAME} or {@value
2454 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2455 * is raised.
2456 *
2457 * <p> If this {@code Class} object represents an array type, then this
2458 * method does not find the {@code clone()} method.
2459 *
2460 * @param name the name of the method
2461 * @param parameterTypes the parameter array
2462 * @return the {@code Method} object for the method of this class
2463 * matching the specified name and parameters
2464 * @throws NoSuchMethodException if a matching method is not found.
2465 * @throws NullPointerException if {@code name} is {@code null}
2466 *
2467 * @jls 8.2 Class Members
2468 * @jls 8.4 Method Declarations
2469 * @since 1.1
2470 */
2471 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2472 throws NoSuchMethodException {
2473 Objects.requireNonNull(name);
2474 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2475 if (method == null) {
2476 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2477 }
2478 return getReflectionFactory().copyMethod(method);
2479 }
2480
2481 /**
2482 * Returns the list of {@code Method} objects for the declared public
2483 * methods of this class or interface that have the specified method name
2484 * and parameter types.
2485 *
2486 * @param name the name of the method
2487 * @param parameterTypes the parameter array
2488 * @return the list of {@code Method} objects for the public methods of
2489 * this class matching the specified name and parameters
2490 */
2491 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2492 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2493 ReflectionFactory factory = getReflectionFactory();
2494 List<Method> result = new ArrayList<>();
2495 for (Method method : methods) {
2496 if (method.getName().equals(name)
2497 && Arrays.equals(
2498 factory.getExecutableSharedParameterTypes(method),
2499 parameterTypes)) {
2500 result.add(factory.copyMethod(method));
2501 }
2502 }
2503 return result;
2504 }
2505
2506 /**
2507 * Returns the most specific {@code Method} object of this class, super class or
2508 * interface that have the specified method name and parameter types.
2509 *
2510 * @param publicOnly true if only public methods are examined, otherwise all methods
2511 * @param name the name of the method
2512 * @param parameterTypes the parameter array
2513 * @return the {@code Method} object for the method found from this class matching
2514 * the specified name and parameters, or null if not found
2515 */
2516 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2517 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2518 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2519 }
2520
2521 /**
2522 * Returns a {@code Constructor} object that reflects the specified
2523 * constructor of the class represented by this
2524 * {@code Class} object. The {@code parameterTypes} parameter is
2525 * an array of {@code Class} objects that identify the constructor's
2526 * formal parameter types, in declared order.
2527 *
2528 * If this {@code Class} object represents an inner class
2529 * declared in a non-static context, the formal parameter types
2530 * include the explicit enclosing instance as the first parameter.
2531 *
2532 * @param parameterTypes the parameter array
2533 * @return The {@code Constructor} object for the constructor with the
2534 * specified parameter list
2535 * @throws NoSuchMethodException if a matching constructor is not found,
2536 * including when this {@code Class} object represents
2537 * an interface, a primitive type, an array class, or void.
2538 *
2539 * @see #getConstructor(Class[])
2540 * @since 1.1
2541 */
2542 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2543 throws NoSuchMethodException {
2544 return getReflectionFactory().copyConstructor(
2545 getConstructor0(parameterTypes, Member.DECLARED));
2546 }
2547
2548 /**
2549 * Finds a resource with a given name.
2550 *
2551 * <p> If this class is in a named {@link Module Module} then this method
2552 * will attempt to find the resource in the module. This is done by
2553 * delegating to the module's class loader {@link
2554 * ClassLoader#findResource(String,String) findResource(String,String)}
2555 * method, invoking it with the module name and the absolute name of the
2556 * resource. Resources in named modules are subject to the rules for
2557 * encapsulation specified in the {@code Module} {@link
2558 * Module#getResourceAsStream getResourceAsStream} method and so this
2559 * method returns {@code null} when the resource is a
2560 * non-"{@code .class}" resource in a package that is not open to the
2561 * caller's module.
2562 *
2563 * <p> Otherwise, if this class is not in a named module then the rules for
2564 * searching resources associated with a given class are implemented by the
2565 * defining {@linkplain ClassLoader class loader} of the class. This method
2566 * delegates to this {@code Class} object's class loader.
2567 * If this {@code Class} object was loaded by the bootstrap class loader,
2568 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2569 *
2570 * <p> Before delegation, an absolute resource name is constructed from the
2571 * given resource name using this algorithm:
2572 *
2573 * <ul>
2574 *
2575 * <li> If the {@code name} begins with a {@code '/'}
2576 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2577 * portion of the {@code name} following the {@code '/'}.
2578 *
2579 * <li> Otherwise, the absolute name is of the following form:
2580 *
2581 * <blockquote>
2582 * {@code modified_package_name/name}
2583 * </blockquote>
2584 *
2585 * <p> Where the {@code modified_package_name} is the package name of this
2586 * object with {@code '/'} substituted for {@code '.'}
2587 * (<code>'\u002e'</code>).
2588 *
2589 * </ul>
2590 *
2591 * @param name name of the desired resource
2592 * @return A {@link java.io.InputStream} object; {@code null} if no
2593 * resource with this name is found, or the resource is in a package
2594 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2595 * least the caller module.
2596 * @throws NullPointerException If {@code name} is {@code null}
2597 *
2598 * @see Module#getResourceAsStream(String)
2599 * @since 1.1
2600 */
2601 @CallerSensitive
2602 public InputStream getResourceAsStream(String name) {
2603 name = resolveName(name);
2604
2605 Module thisModule = getModule();
2606 if (thisModule.isNamed()) {
2607 // check if resource can be located by caller
2608 if (Resources.canEncapsulate(name)
2609 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2610 return null;
2611 }
2612
2613 // resource not encapsulated or in package open to caller
2614 String mn = thisModule.getName();
2615 ClassLoader cl = classLoader;
2616 try {
2617
2618 // special-case built-in class loaders to avoid the
2619 // need for a URL connection
2620 if (cl == null) {
2621 return BootLoader.findResourceAsStream(mn, name);
2622 } else if (cl instanceof BuiltinClassLoader bcl) {
2623 return bcl.findResourceAsStream(mn, name);
2624 } else {
2625 URL url = cl.findResource(mn, name);
2626 return (url != null) ? url.openStream() : null;
2627 }
2628
2629 } catch (IOException | SecurityException e) {
2630 return null;
2631 }
2632 }
2633
2634 // unnamed module
2635 ClassLoader cl = classLoader;
2636 if (cl == null) {
2637 return ClassLoader.getSystemResourceAsStream(name);
2638 } else {
2639 return cl.getResourceAsStream(name);
2640 }
2641 }
2642
2643 /**
2644 * Finds a resource with a given name.
2645 *
2646 * <p> If this class is in a named {@link Module Module} then this method
2647 * will attempt to find the resource in the module. This is done by
2648 * delegating to the module's class loader {@link
2649 * ClassLoader#findResource(String,String) findResource(String,String)}
2650 * method, invoking it with the module name and the absolute name of the
2651 * resource. Resources in named modules are subject to the rules for
2652 * encapsulation specified in the {@code Module} {@link
2653 * Module#getResourceAsStream getResourceAsStream} method and so this
2654 * method returns {@code null} when the resource is a
2655 * non-"{@code .class}" resource in a package that is not open to the
2656 * caller's module.
2657 *
2658 * <p> Otherwise, if this class is not in a named module then the rules for
2659 * searching resources associated with a given class are implemented by the
2660 * defining {@linkplain ClassLoader class loader} of the class. This method
2661 * delegates to this {@code Class} object's class loader.
2662 * If this {@code Class} object was loaded by the bootstrap class loader,
2663 * the method delegates to {@link ClassLoader#getSystemResource}.
2664 *
2665 * <p> Before delegation, an absolute resource name is constructed from the
2666 * given resource name using this algorithm:
2667 *
2668 * <ul>
2669 *
2670 * <li> If the {@code name} begins with a {@code '/'}
2671 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2672 * portion of the {@code name} following the {@code '/'}.
2673 *
2674 * <li> Otherwise, the absolute name is of the following form:
2675 *
2676 * <blockquote>
2677 * {@code modified_package_name/name}
2678 * </blockquote>
2679 *
2680 * <p> Where the {@code modified_package_name} is the package name of this
2681 * object with {@code '/'} substituted for {@code '.'}
2682 * (<code>'\u002e'</code>).
2683 *
2684 * </ul>
2685 *
2686 * @param name name of the desired resource
2687 * @return A {@link java.net.URL} object; {@code null} if no resource with
2688 * this name is found, the resource cannot be located by a URL, or the
2689 * resource is in a package that is not
2690 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2691 * module.
2692 * @throws NullPointerException If {@code name} is {@code null}
2693 * @since 1.1
2694 */
2695 @CallerSensitive
2696 public URL getResource(String name) {
2697 name = resolveName(name);
2698
2699 Module thisModule = getModule();
2700 if (thisModule.isNamed()) {
2701 // check if resource can be located by caller
2702 if (Resources.canEncapsulate(name)
2703 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2704 return null;
2705 }
2706
2707 // resource not encapsulated or in package open to caller
2708 String mn = thisModule.getName();
2709 ClassLoader cl = classLoader;
2710 try {
2711 if (cl == null) {
2712 return BootLoader.findResource(mn, name);
2713 } else {
2714 return cl.findResource(mn, name);
2715 }
2716 } catch (IOException ioe) {
2717 return null;
2718 }
2719 }
2720
2721 // unnamed module
2722 ClassLoader cl = classLoader;
2723 if (cl == null) {
2724 return ClassLoader.getSystemResource(name);
2725 } else {
2726 return cl.getResource(name);
2727 }
2728 }
2729
2730 /**
2731 * Returns true if a resource with the given name can be located by the
2732 * given caller. All resources in a module can be located by code in
2733 * the module. For other callers, then the package needs to be open to
2734 * the caller.
2735 */
2736 private boolean isOpenToCaller(String name, Class<?> caller) {
2737 // assert getModule().isNamed();
2738 Module thisModule = getModule();
2739 Module callerModule = (caller != null) ? caller.getModule() : null;
2740 if (callerModule != thisModule) {
2741 String pn = Resources.toPackageName(name);
2742 if (thisModule.getDescriptor().packages().contains(pn)) {
2743 if (callerModule == null) {
2744 // no caller, return true if the package is open to all modules
2745 return thisModule.isOpen(pn);
2746 }
2747 if (!thisModule.isOpen(pn, callerModule)) {
2748 // package not open to caller
2749 return false;
2750 }
2751 }
2752 }
2753 return true;
2754 }
2755
2756 private transient final ProtectionDomain protectionDomain;
2757
2758 /** Holder for the protection domain returned when the internal domain is null */
2759 private static class Holder {
2760 private static final ProtectionDomain allPermDomain;
2761 static {
2762 Permissions perms = new Permissions();
2763 perms.add(new AllPermission());
2764 allPermDomain = new ProtectionDomain(null, perms);
2765 }
2766 }
2767
2768 /**
2769 * Returns the {@code ProtectionDomain} of this class.
2770 *
2771 * @return the ProtectionDomain of this class
2772 *
2773 * @see java.security.ProtectionDomain
2774 * @since 1.2
2775 */
2776 public ProtectionDomain getProtectionDomain() {
2777 if (protectionDomain == null) {
2778 return Holder.allPermDomain;
2779 } else {
2780 return protectionDomain;
2781 }
2782 }
2783
2784 /*
2785 * Returns the Class object for the named primitive type. Type parameter T
2786 * avoids redundant casts for trusted code.
2787 */
2788 static native <T> Class<T> getPrimitiveClass(String name);
2789
2790 /**
2791 * Add a package name prefix if the name is not absolute. Remove leading "/"
2792 * if name is absolute
2793 */
2794 private String resolveName(String name) {
2795 if (!name.startsWith("/")) {
2796 String baseName = getPackageName();
2797 if (!baseName.isEmpty()) {
2798 int len = baseName.length() + 1 + name.length();
2799 StringBuilder sb = new StringBuilder(len);
2800 name = sb.append(baseName.replace('.', '/'))
2801 .append('/')
2802 .append(name)
2803 .toString();
2804 }
2805 } else {
2806 name = name.substring(1);
2807 }
2808 return name;
2809 }
2810
2811 /**
2812 * Atomic operations support.
2813 */
2814 private static class Atomic {
2815 // initialize Unsafe machinery here, since we need to call Class.class instance method
2816 // and have to avoid calling it in the static initializer of the Class class...
2817 private static final Unsafe unsafe = Unsafe.getUnsafe();
2818 // offset of Class.reflectionData instance field
2819 private static final long reflectionDataOffset
2820 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2821 // offset of Class.annotationType instance field
2822 private static final long annotationTypeOffset
2823 = unsafe.objectFieldOffset(Class.class, "annotationType");
2824 // offset of Class.annotationData instance field
2825 private static final long annotationDataOffset
2826 = unsafe.objectFieldOffset(Class.class, "annotationData");
2827
2828 static <T> boolean casReflectionData(Class<?> clazz,
2829 SoftReference<ReflectionData<T>> oldData,
2830 SoftReference<ReflectionData<T>> newData) {
2831 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2832 }
2833
2834 static boolean casAnnotationType(Class<?> clazz,
2835 AnnotationType oldType,
2836 AnnotationType newType) {
2837 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2838 }
2839
2840 static boolean casAnnotationData(Class<?> clazz,
2841 AnnotationData oldData,
2842 AnnotationData newData) {
2843 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2844 }
2845 }
2846
2847 /**
2848 * Reflection support.
2849 */
2850
2851 // Reflection data caches various derived names and reflective members. Cached
2852 // values may be invalidated when JVM TI RedefineClasses() is called
2853 private static class ReflectionData<T> {
2854 volatile Field[] declaredFields;
2855 volatile Field[] publicFields;
2856 volatile Method[] declaredMethods;
2857 volatile Method[] publicMethods;
2858 volatile Constructor<T>[] declaredConstructors;
2859 volatile Constructor<T>[] publicConstructors;
2860 // Intermediate results for getFields and getMethods
2861 volatile Field[] declaredPublicFields;
2862 volatile Method[] declaredPublicMethods;
2863 volatile Class<?>[] interfaces;
2864
2865 // Cached names
2866 String simpleName;
2867 String canonicalName;
2868 static final String NULL_SENTINEL = new String();
2869
2870 // Value of classRedefinedCount when we created this ReflectionData instance
2871 final int redefinedCount;
2872
2873 ReflectionData(int redefinedCount) {
2874 this.redefinedCount = redefinedCount;
2875 }
2876 }
2877
2878 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2879
2880 // Incremented by the VM on each call to JVM TI RedefineClasses()
2881 // that redefines this class or a superclass.
2882 private transient volatile int classRedefinedCount;
2883
2884 // Lazily create and cache ReflectionData
2885 private ReflectionData<T> reflectionData() {
2886 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2887 int classRedefinedCount = this.classRedefinedCount;
2888 ReflectionData<T> rd;
2889 if (reflectionData != null &&
2890 (rd = reflectionData.get()) != null &&
2891 rd.redefinedCount == classRedefinedCount) {
2892 return rd;
2893 }
2894 // else no SoftReference or cleared SoftReference or stale ReflectionData
2895 // -> create and replace new instance
2896 return newReflectionData(reflectionData, classRedefinedCount);
2897 }
2898
2899 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2900 int classRedefinedCount) {
2901 while (true) {
2902 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2903 // try to CAS it...
2904 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
2905 return rd;
2906 }
2907 // else retry
2908 oldReflectionData = this.reflectionData;
2909 classRedefinedCount = this.classRedefinedCount;
2910 if (oldReflectionData != null &&
2911 (rd = oldReflectionData.get()) != null &&
2912 rd.redefinedCount == classRedefinedCount) {
2913 return rd;
2914 }
2915 }
2916 }
2917
2918 // Generic signature handling
2919 private native String getGenericSignature0();
2920
2921 // Generic info repository; lazily initialized
2922 private transient volatile ClassRepository genericInfo;
2923
2924 // accessor for factory
2925 private GenericsFactory getFactory() {
2926 // create scope and factory
2927 return CoreReflectionFactory.make(this, ClassScope.make(this));
2928 }
2929
2930 // accessor for generic info repository;
2931 // generic info is lazily initialized
2932 private ClassRepository getGenericInfo() {
2933 ClassRepository genericInfo = this.genericInfo;
2934 if (genericInfo == null) {
2935 String signature = getGenericSignature0();
2936 if (signature == null) {
2937 genericInfo = ClassRepository.NONE;
2938 } else {
2939 genericInfo = ClassRepository.make(signature, getFactory());
2940 }
2941 this.genericInfo = genericInfo;
2942 }
2943 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2944 }
2945
2946 // Annotations handling
2947 native byte[] getRawAnnotations();
2948 // Since 1.8
2949 native byte[] getRawTypeAnnotations();
2950 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2951 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2952 }
2953
2954 native ConstantPool getConstantPool();
2955
2956 //
2957 //
2958 // java.lang.reflect.Field handling
2959 //
2960 //
2961
2962 // Returns an array of "root" fields. These Field objects must NOT
2963 // be propagated to the outside world, but must instead be copied
2964 // via ReflectionFactory.copyField.
2965 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2966 Field[] res;
2967 ReflectionData<T> rd = reflectionData();
2968 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2969 if (res != null) return res;
2970 // No cached value available; request value from VM
2971 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2972 if (publicOnly) {
2973 rd.declaredPublicFields = res;
2974 } else {
2975 rd.declaredFields = res;
2976 }
2977 return res;
2978 }
2979
2980 // Returns an array of "root" fields. These Field objects must NOT
2981 // be propagated to the outside world, but must instead be copied
2982 // via ReflectionFactory.copyField.
2983 private Field[] privateGetPublicFields() {
2984 Field[] res;
2985 ReflectionData<T> rd = reflectionData();
2986 res = rd.publicFields;
2987 if (res != null) return res;
2988
2989 // Use a linked hash set to ensure order is preserved and
2990 // fields from common super interfaces are not duplicated
2991 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2992
2993 // Local fields
2994 addAll(fields, privateGetDeclaredFields(true));
2995
2996 // Direct superinterfaces, recursively
2997 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2998 addAll(fields, si.privateGetPublicFields());
2999 }
3000
3001 // Direct superclass, recursively
3002 Class<?> sc = getSuperclass();
3003 if (sc != null) {
3004 addAll(fields, sc.privateGetPublicFields());
3005 }
3006
3007 res = fields.toArray(new Field[0]);
3008 rd.publicFields = res;
3009 return res;
3010 }
3011
3012 private static void addAll(Collection<Field> c, Field[] o) {
3013 for (Field f : o) {
3014 c.add(f);
3015 }
3016 }
3017
3018
3019 //
3020 //
3021 // java.lang.reflect.Constructor handling
3022 //
3023 //
3024
3025 // Returns an array of "root" constructors. These Constructor
3026 // objects must NOT be propagated to the outside world, but must
3027 // instead be copied via ReflectionFactory.copyConstructor.
3028 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3029 Constructor<T>[] res;
3030 ReflectionData<T> rd = reflectionData();
3031 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3032 if (res != null) return res;
3033 // No cached value available; request value from VM
3034 if (isInterface()) {
3035 @SuppressWarnings("unchecked")
3036 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3037 res = temporaryRes;
3038 } else {
3039 res = getDeclaredConstructors0(publicOnly);
3040 }
3041 if (publicOnly) {
3042 rd.publicConstructors = res;
3043 } else {
3044 rd.declaredConstructors = res;
3045 }
3046 return res;
3047 }
3048
3049 //
3050 //
3051 // java.lang.reflect.Method handling
3052 //
3053 //
3054
3055 // Returns an array of "root" methods. These Method objects must NOT
3056 // be propagated to the outside world, but must instead be copied
3057 // via ReflectionFactory.copyMethod.
3058 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3059 Method[] res;
3060 ReflectionData<T> rd = reflectionData();
3061 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3062 if (res != null) return res;
3063 // No cached value available; request value from VM
3064 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3065 if (publicOnly) {
3066 rd.declaredPublicMethods = res;
3067 } else {
3068 rd.declaredMethods = res;
3069 }
3070 return res;
3071 }
3072
3073 // Returns an array of "root" methods. These Method objects must NOT
3074 // be propagated to the outside world, but must instead be copied
3075 // via ReflectionFactory.copyMethod.
3076 private Method[] privateGetPublicMethods() {
3077 Method[] res;
3078 ReflectionData<T> rd = reflectionData();
3079 res = rd.publicMethods;
3080 if (res != null) return res;
3081
3082 // No cached value available; compute value recursively.
3083 // Start by fetching public declared methods...
3084 PublicMethods pms = new PublicMethods();
3085 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3086 pms.merge(m);
3087 }
3088 // ...then recur over superclass methods...
3089 Class<?> sc = getSuperclass();
3090 if (sc != null) {
3091 for (Method m : sc.privateGetPublicMethods()) {
3092 pms.merge(m);
3093 }
3094 }
3095 // ...and finally over direct superinterfaces.
3096 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3097 for (Method m : intf.privateGetPublicMethods()) {
3098 // static interface methods are not inherited
3099 if (!Modifier.isStatic(m.getModifiers())) {
3100 pms.merge(m);
3101 }
3102 }
3103 }
3104
3105 res = pms.toArray();
3106 rd.publicMethods = res;
3107 return res;
3108 }
3109
3110
3111 //
3112 // Helpers for fetchers of one field, method, or constructor
3113 //
3114
3115 // This method does not copy the returned Field object!
3116 private static Field searchFields(Field[] fields, String name) {
3117 for (Field field : fields) {
3118 if (field.getName().equals(name)) {
3119 return field;
3120 }
3121 }
3122 return null;
3123 }
3124
3125 // Returns a "root" Field object. This Field object must NOT
3126 // be propagated to the outside world, but must instead be copied
3127 // via ReflectionFactory.copyField.
3128 private Field getField0(String name) {
3129 // Note: the intent is that the search algorithm this routine
3130 // uses be equivalent to the ordering imposed by
3131 // privateGetPublicFields(). It fetches only the declared
3132 // public fields for each class, however, to reduce the number
3133 // of Field objects which have to be created for the common
3134 // case where the field being requested is declared in the
3135 // class which is being queried.
3136 Field res;
3137 // Search declared public fields
3138 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3139 return res;
3140 }
3141 // Direct superinterfaces, recursively
3142 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3143 for (Class<?> c : interfaces) {
3144 if ((res = c.getField0(name)) != null) {
3145 return res;
3146 }
3147 }
3148 // Direct superclass, recursively
3149 if (!isInterface()) {
3150 Class<?> c = getSuperclass();
3151 if (c != null) {
3152 if ((res = c.getField0(name)) != null) {
3153 return res;
3154 }
3155 }
3156 }
3157 return null;
3158 }
3159
3160 // This method does not copy the returned Method object!
3161 private static Method searchMethods(Method[] methods,
3162 String name,
3163 Class<?>[] parameterTypes)
3164 {
3165 ReflectionFactory fact = getReflectionFactory();
3166 Method res = null;
3167 for (Method m : methods) {
3168 if (m.getName().equals(name)
3169 && arrayContentsEq(parameterTypes,
3170 fact.getExecutableSharedParameterTypes(m))
3171 && (res == null
3172 || (res.getReturnType() != m.getReturnType()
3173 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3174 res = m;
3175 }
3176 return res;
3177 }
3178
3179 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3180
3181 // Returns a "root" Method object. This Method object must NOT
3182 // be propagated to the outside world, but must instead be copied
3183 // via ReflectionFactory.copyMethod.
3184 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3185 PublicMethods.MethodList res = getMethodsRecursive(
3186 name,
3187 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3188 /* includeStatic */ true, /* publicOnly */ true);
3189 return res == null ? null : res.getMostSpecific();
3190 }
3191
3192 // Returns a list of "root" Method objects. These Method objects must NOT
3193 // be propagated to the outside world, but must instead be copied
3194 // via ReflectionFactory.copyMethod.
3195 private PublicMethods.MethodList getMethodsRecursive(String name,
3196 Class<?>[] parameterTypes,
3197 boolean includeStatic,
3198 boolean publicOnly) {
3199 // 1st check declared methods
3200 Method[] methods = privateGetDeclaredMethods(publicOnly);
3201 PublicMethods.MethodList res = PublicMethods.MethodList
3202 .filter(methods, name, parameterTypes, includeStatic);
3203 // if there is at least one match among declared methods, we need not
3204 // search any further as such match surely overrides matching methods
3205 // declared in superclass(es) or interface(s).
3206 if (res != null) {
3207 return res;
3208 }
3209
3210 // if there was no match among declared methods,
3211 // we must consult the superclass (if any) recursively...
3212 Class<?> sc = getSuperclass();
3213 if (sc != null) {
3214 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3215 }
3216
3217 // ...and coalesce the superclass methods with methods obtained
3218 // from directly implemented interfaces excluding static methods...
3219 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3220 res = PublicMethods.MethodList.merge(
3221 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3222 }
3223
3224 return res;
3225 }
3226
3227 // Returns a "root" Constructor object. This Constructor object must NOT
3228 // be propagated to the outside world, but must instead be copied
3229 // via ReflectionFactory.copyConstructor.
3230 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3231 int which) throws NoSuchMethodException
3232 {
3233 ReflectionFactory fact = getReflectionFactory();
3234 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3235 for (Constructor<T> constructor : constructors) {
3236 if (arrayContentsEq(parameterTypes,
3237 fact.getExecutableSharedParameterTypes(constructor))) {
3238 return constructor;
3239 }
3240 }
3241 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3242 }
3243
3244 //
3245 // Other helpers and base implementation
3246 //
3247
3248 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3249 if (a1 == null) {
3250 return a2 == null || a2.length == 0;
3251 }
3252
3253 if (a2 == null) {
3254 return a1.length == 0;
3255 }
3256
3257 if (a1.length != a2.length) {
3258 return false;
3259 }
3260
3261 for (int i = 0; i < a1.length; i++) {
3262 if (a1[i] != a2[i]) {
3263 return false;
3264 }
3265 }
3266
3267 return true;
3268 }
3269
3270 private static Field[] copyFields(Field[] arg) {
3271 Field[] out = new Field[arg.length];
3272 ReflectionFactory fact = getReflectionFactory();
3273 for (int i = 0; i < arg.length; i++) {
3274 out[i] = fact.copyField(arg[i]);
3275 }
3276 return out;
3277 }
3278
3279 private static Method[] copyMethods(Method[] arg) {
3280 Method[] out = new Method[arg.length];
3281 ReflectionFactory fact = getReflectionFactory();
3282 for (int i = 0; i < arg.length; i++) {
3283 out[i] = fact.copyMethod(arg[i]);
3284 }
3285 return out;
3286 }
3287
3288 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3289 Constructor<U>[] out = arg.clone();
3290 ReflectionFactory fact = getReflectionFactory();
3291 for (int i = 0; i < out.length; i++) {
3292 out[i] = fact.copyConstructor(out[i]);
3293 }
3294 return out;
3295 }
3296
3297 private native Field[] getDeclaredFields0(boolean publicOnly);
3298 private native Method[] getDeclaredMethods0(boolean publicOnly);
3299 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3300 private native Class<?>[] getDeclaredClasses0();
3301
3302 /*
3303 * Returns an array containing the components of the Record attribute,
3304 * or null if the attribute is not present.
3305 *
3306 * Note that this method returns non-null array on a class with
3307 * the Record attribute even if this class is not a record.
3308 */
3309 private native RecordComponent[] getRecordComponents0();
3310 private native boolean isRecord0();
3311
3312 /**
3313 * Helper method to get the method name from arguments.
3314 */
3315 private String methodToString(String name, Class<?>[] argTypes) {
3316 return getName() + '.' + name +
3317 ((argTypes == null || argTypes.length == 0) ?
3318 "()" :
3319 Arrays.stream(argTypes)
3320 .map(c -> c == null ? "null" : c.getName())
3321 .collect(Collectors.joining(",", "(", ")")));
3322 }
3323
3324 /** use serialVersionUID from JDK 1.1 for interoperability */
3325 @java.io.Serial
3326 private static final long serialVersionUID = 3206093459760846163L;
3327
3328
3329 /**
3330 * Class Class is special cased within the Serialization Stream Protocol.
3331 *
3332 * A Class instance is written initially into an ObjectOutputStream in the
3333 * following format:
3334 * <pre>
3335 * {@code TC_CLASS} ClassDescriptor
3336 * A ClassDescriptor is a special cased serialization of
3337 * a {@code java.io.ObjectStreamClass} instance.
3338 * </pre>
3339 * A new handle is generated for the initial time the class descriptor
3340 * is written into the stream. Future references to the class descriptor
3341 * are written as references to the initial class descriptor instance.
3342 *
3343 * @see java.io.ObjectStreamClass
3344 */
3345 @java.io.Serial
3346 private static final ObjectStreamField[] serialPersistentFields =
3347 new ObjectStreamField[0];
3348
3349
3350 /**
3351 * Returns the assertion status that would be assigned to this
3352 * class if it were to be initialized at the time this method is invoked.
3353 * If this class has had its assertion status set, the most recent
3354 * setting will be returned; otherwise, if any package default assertion
3355 * status pertains to this class, the most recent setting for the most
3356 * specific pertinent package default assertion status is returned;
3357 * otherwise, if this class is not a system class (i.e., it has a
3358 * class loader) its class loader's default assertion status is returned;
3359 * otherwise, the system class default assertion status is returned.
3360 *
3361 * @apiNote
3362 * Few programmers will have any need for this method; it is provided
3363 * for the benefit of the JDK itself. (It allows a class to determine at
3364 * the time that it is initialized whether assertions should be enabled.)
3365 * Note that this method is not guaranteed to return the actual
3366 * assertion status that was (or will be) associated with the specified
3367 * class when it was (or will be) initialized.
3368 *
3369 * @return the desired assertion status of the specified class.
3370 * @see java.lang.ClassLoader#setClassAssertionStatus
3371 * @see java.lang.ClassLoader#setPackageAssertionStatus
3372 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3373 * @since 1.4
3374 */
3375 public boolean desiredAssertionStatus() {
3376 ClassLoader loader = classLoader;
3377 // If the loader is null this is a system class, so ask the VM
3378 if (loader == null)
3379 return desiredAssertionStatus0(this);
3380
3381 // If the classloader has been initialized with the assertion
3382 // directives, ask it. Otherwise, ask the VM.
3383 synchronized(loader.assertionLock) {
3384 if (loader.classAssertionStatus != null) {
3385 return loader.desiredAssertionStatus(getName());
3386 }
3387 }
3388 return desiredAssertionStatus0(this);
3389 }
3390
3391 // Retrieves the desired assertion status of this class from the VM
3392 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3393
3394 /**
3395 * Returns true if and only if this class was declared as an enum in the
3396 * source code.
3397 *
3398 * Note that {@link java.lang.Enum} is not itself an enum class.
3399 *
3400 * Also note that if an enum constant is declared with a class body,
3401 * the class of that enum constant object is an anonymous class
3402 * and <em>not</em> the class of the declaring enum class. The
3403 * {@link Enum#getDeclaringClass} method of an enum constant can
3404 * be used to get the class of the enum class declaring the
3405 * constant.
3406 *
3407 * @return true if and only if this class was declared as an enum in the
3408 * source code
3409 * @since 1.5
3410 * @jls 8.9.1 Enum Constants
3411 */
3412 public boolean isEnum() {
3413 // An enum must both directly extend java.lang.Enum and have
3414 // the ENUM bit set; classes for specialized enum constants
3415 // don't do the former.
3416 return (this.getModifiers() & ENUM) != 0 &&
3417 this.getSuperclass() == java.lang.Enum.class;
3418 }
3419
3420 /**
3421 * Returns {@code true} if and only if this class is a record class.
3422 *
3423 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3424 * class is {@code java.lang.Record}. A record class is {@linkplain
3425 * Modifier#FINAL final}. A record class has (possibly zero) record
3426 * components; {@link #getRecordComponents()} returns a non-null but
3427 * possibly empty value for a record.
3428 *
3429 * <p> Note that class {@link Record} is not a record class and thus
3430 * invoking this method on class {@code Record} returns {@code false}.
3431 *
3432 * @return true if and only if this class is a record class, otherwise false
3433 * @jls 8.10 Record Classes
3434 * @since 16
3435 */
3436 public boolean isRecord() {
3437 // this superclass and final modifier check is not strictly necessary
3438 // they are intrinsified and serve as a fast-path check
3439 return getSuperclass() == java.lang.Record.class &&
3440 (this.getModifiers() & Modifier.FINAL) != 0 &&
3441 isRecord0();
3442 }
3443
3444 // Fetches the factory for reflective objects
3445 private static ReflectionFactory getReflectionFactory() {
3446 var factory = reflectionFactory;
3447 if (factory != null) {
3448 return factory;
3449 }
3450 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3451 }
3452 private static ReflectionFactory reflectionFactory;
3453
3454 /**
3455 * When CDS is enabled, the Class class may be aot-initialized. However,
3456 * we can't archive reflectionFactory, so we reset it to null, so it
3457 * will be allocated again at runtime.
3458 */
3459 private static void resetArchivedStates() {
3460 reflectionFactory = null;
3461 }
3462
3463 /**
3464 * Returns the elements of this enum class or null if this
3465 * Class object does not represent an enum class.
3466 *
3467 * @return an array containing the values comprising the enum class
3468 * represented by this {@code Class} object in the order they're
3469 * declared, or null if this {@code Class} object does not
3470 * represent an enum class
3471 * @since 1.5
3472 * @jls 8.9.1 Enum Constants
3473 */
3474 public T[] getEnumConstants() {
3475 T[] values = getEnumConstantsShared();
3476 return (values != null) ? values.clone() : null;
3477 }
3478
3479 /**
3480 * Returns the elements of this enum class or null if this
3481 * Class object does not represent an enum class;
3482 * identical to getEnumConstants except that the result is
3483 * uncloned, cached, and shared by all callers.
3484 */
3485 T[] getEnumConstantsShared() {
3486 T[] constants = enumConstants;
3487 if (constants == null) {
3488 if (!isEnum()) return null;
3489 try {
3490 final Method values = getMethod("values");
3491 values.setAccessible(true);
3492 @SuppressWarnings("unchecked")
3493 T[] temporaryConstants = (T[])values.invoke(null);
3494 enumConstants = constants = temporaryConstants;
3495 }
3496 // These can happen when users concoct enum-like classes
3497 // that don't comply with the enum spec.
3498 catch (InvocationTargetException | NoSuchMethodException |
3499 IllegalAccessException | NullPointerException |
3500 ClassCastException ex) { return null; }
3501 }
3502 return constants;
3503 }
3504 private transient volatile T[] enumConstants;
3505
3506 /**
3507 * Returns a map from simple name to enum constant. This package-private
3508 * method is used internally by Enum to implement
3509 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3510 * efficiently. Note that the map is returned by this method is
3511 * created lazily on first use. Typically it won't ever get created.
3512 */
3513 Map<String, T> enumConstantDirectory() {
3514 Map<String, T> directory = enumConstantDirectory;
3515 if (directory == null) {
3516 T[] universe = getEnumConstantsShared();
3517 if (universe == null)
3518 throw new IllegalArgumentException(
3519 getName() + " is not an enum class");
3520 directory = HashMap.newHashMap(universe.length);
3521 for (T constant : universe) {
3522 directory.put(((Enum<?>)constant).name(), constant);
3523 }
3524 enumConstantDirectory = directory;
3525 }
3526 return directory;
3527 }
3528 private transient volatile Map<String, T> enumConstantDirectory;
3529
3530 /**
3531 * Casts an object to the class or interface represented
3532 * by this {@code Class} object.
3533 *
3534 * @param obj the object to be cast
3535 * @return the object after casting, or null if obj is null
3536 *
3537 * @throws ClassCastException if the object is not
3538 * null and is not assignable to the type T.
3539 *
3540 * @since 1.5
3541 */
3542 @SuppressWarnings("unchecked")
3543 @IntrinsicCandidate
3544 public T cast(Object obj) {
3545 if (obj != null && !isInstance(obj))
3546 throw new ClassCastException(cannotCastMsg(obj));
3547 return (T) obj;
3548 }
3549
3550 private String cannotCastMsg(Object obj) {
3551 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3552 }
3553
3554 /**
3555 * Casts this {@code Class} object to represent a subclass of the class
3556 * represented by the specified class object. Checks that the cast
3557 * is valid, and throws a {@code ClassCastException} if it is not. If
3558 * this method succeeds, it always returns a reference to this {@code Class} object.
3559 *
3560 * <p>This method is useful when a client needs to "narrow" the type of
3561 * a {@code Class} object to pass it to an API that restricts the
3562 * {@code Class} objects that it is willing to accept. A cast would
3563 * generate a compile-time warning, as the correctness of the cast
3564 * could not be checked at runtime (because generic types are implemented
3565 * by erasure).
3566 *
3567 * @param <U> the type to cast this {@code Class} object to
3568 * @param clazz the class of the type to cast this {@code Class} object to
3569 * @return this {@code Class} object, cast to represent a subclass of
3570 * the specified class object.
3571 * @throws ClassCastException if this {@code Class} object does not
3572 * represent a subclass of the specified class (here "subclass" includes
3573 * the class itself).
3574 * @since 1.5
3575 */
3576 @SuppressWarnings("unchecked")
3577 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3578 if (clazz.isAssignableFrom(this))
3579 return (Class<? extends U>) this;
3580 else
3581 throw new ClassCastException(this.toString());
3582 }
3583
3584 /**
3585 * {@inheritDoc}
3586 * <p>Note that any annotation returned by this method is a
3587 * declaration annotation.
3588 *
3589 * @throws NullPointerException {@inheritDoc}
3590 * @since 1.5
3591 */
3592 @Override
3593 @SuppressWarnings("unchecked")
3594 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3595 Objects.requireNonNull(annotationClass);
3596
3597 return (A) annotationData().annotations.get(annotationClass);
3598 }
3599
3600 /**
3601 * {@inheritDoc}
3602 * @throws NullPointerException {@inheritDoc}
3603 * @since 1.5
3604 */
3605 @Override
3606 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3607 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3608 }
3609
3610 /**
3611 * {@inheritDoc}
3612 * <p>Note that any annotations returned by this method are
3613 * declaration annotations.
3614 *
3615 * @throws NullPointerException {@inheritDoc}
3616 * @since 1.8
3617 */
3618 @Override
3619 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3620 Objects.requireNonNull(annotationClass);
3621
3622 AnnotationData annotationData = annotationData();
3623 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3624 this,
3625 annotationClass);
3626 }
3627
3628 /**
3629 * {@inheritDoc}
3630 * <p>Note that any annotations returned by this method are
3631 * declaration annotations.
3632 *
3633 * @since 1.5
3634 */
3635 @Override
3636 public Annotation[] getAnnotations() {
3637 return AnnotationParser.toArray(annotationData().annotations);
3638 }
3639
3640 /**
3641 * {@inheritDoc}
3642 * <p>Note that any annotation returned by this method is a
3643 * declaration annotation.
3644 *
3645 * @throws NullPointerException {@inheritDoc}
3646 * @since 1.8
3647 */
3648 @Override
3649 @SuppressWarnings("unchecked")
3650 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3651 Objects.requireNonNull(annotationClass);
3652
3653 return (A) annotationData().declaredAnnotations.get(annotationClass);
3654 }
3655
3656 /**
3657 * {@inheritDoc}
3658 * <p>Note that any annotations returned by this method are
3659 * declaration annotations.
3660 *
3661 * @throws NullPointerException {@inheritDoc}
3662 * @since 1.8
3663 */
3664 @Override
3665 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3666 Objects.requireNonNull(annotationClass);
3667
3668 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3669 annotationClass);
3670 }
3671
3672 /**
3673 * {@inheritDoc}
3674 * <p>Note that any annotations returned by this method are
3675 * declaration annotations.
3676 *
3677 * @since 1.5
3678 */
3679 @Override
3680 public Annotation[] getDeclaredAnnotations() {
3681 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3682 }
3683
3684 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3685 private static class AnnotationData {
3686 final Map<Class<? extends Annotation>, Annotation> annotations;
3687 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3688
3689 // Value of classRedefinedCount when we created this AnnotationData instance
3690 final int redefinedCount;
3691
3692 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3693 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3694 int redefinedCount) {
3695 this.annotations = annotations;
3696 this.declaredAnnotations = declaredAnnotations;
3697 this.redefinedCount = redefinedCount;
3698 }
3699 }
3700
3701 // Annotations cache
3702 @SuppressWarnings("UnusedDeclaration")
3703 private transient volatile AnnotationData annotationData;
3704
3705 private AnnotationData annotationData() {
3706 while (true) { // retry loop
3707 AnnotationData annotationData = this.annotationData;
3708 int classRedefinedCount = this.classRedefinedCount;
3709 if (annotationData != null &&
3710 annotationData.redefinedCount == classRedefinedCount) {
3711 return annotationData;
3712 }
3713 // null or stale annotationData -> optimistically create new instance
3714 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3715 // try to install it
3716 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3717 // successfully installed new AnnotationData
3718 return newAnnotationData;
3719 }
3720 }
3721 }
3722
3723 private AnnotationData createAnnotationData(int classRedefinedCount) {
3724 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3725 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3726 Class<?> superClass = getSuperclass();
3727 Map<Class<? extends Annotation>, Annotation> annotations = null;
3728 if (superClass != null) {
3729 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3730 superClass.annotationData().annotations;
3731 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3732 Class<? extends Annotation> annotationClass = e.getKey();
3733 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3734 if (annotations == null) { // lazy construction
3735 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3736 declaredAnnotations.size(),
3737 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3738 )
3739 );
3740 }
3741 annotations.put(annotationClass, e.getValue());
3742 }
3743 }
3744 }
3745 if (annotations == null) {
3746 // no inherited annotations -> share the Map with declaredAnnotations
3747 annotations = declaredAnnotations;
3748 } else {
3749 // at least one inherited annotation -> declared may override inherited
3750 annotations.putAll(declaredAnnotations);
3751 }
3752 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3753 }
3754
3755 // Annotation interfaces cache their internal (AnnotationType) form
3756
3757 @SuppressWarnings("UnusedDeclaration")
3758 private transient volatile AnnotationType annotationType;
3759
3760 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3761 return Atomic.casAnnotationType(this, oldType, newType);
3762 }
3763
3764 AnnotationType getAnnotationType() {
3765 return annotationType;
3766 }
3767
3768 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3769 return annotationData().declaredAnnotations;
3770 }
3771
3772 /* Backing store of user-defined values pertaining to this class.
3773 * Maintained by the ClassValue class.
3774 */
3775 transient ClassValue.ClassValueMap classValueMap;
3776
3777 /**
3778 * Returns an {@code AnnotatedType} object that represents the use of a
3779 * type to specify the superclass of the entity represented by this {@code
3780 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3781 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3782 * Foo.)
3783 *
3784 * <p> If this {@code Class} object represents a class whose declaration
3785 * does not explicitly indicate an annotated superclass, then the return
3786 * value is an {@code AnnotatedType} object representing an element with no
3787 * annotations.
3788 *
3789 * <p> If this {@code Class} represents either the {@code Object} class, an
3790 * interface type, an array type, a primitive type, or void, the return
3791 * value is {@code null}.
3792 *
3793 * @return an object representing the superclass
3794 * @since 1.8
3795 */
3796 public AnnotatedType getAnnotatedSuperclass() {
3797 if (this == Object.class ||
3798 isInterface() ||
3799 isArray() ||
3800 isPrimitive() ||
3801 this == Void.TYPE) {
3802 return null;
3803 }
3804
3805 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3806 }
3807
3808 /**
3809 * Returns an array of {@code AnnotatedType} objects that represent the use
3810 * of types to specify superinterfaces of the entity represented by this
3811 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3812 * superinterface in '... implements Foo' is distinct from the
3813 * <em>declaration</em> of interface Foo.)
3814 *
3815 * <p> If this {@code Class} object represents a class, the return value is
3816 * an array containing objects representing the uses of interface types to
3817 * specify interfaces implemented by the class. The order of the objects in
3818 * the array corresponds to the order of the interface types used in the
3819 * 'implements' clause of the declaration of this {@code Class} object.
3820 *
3821 * <p> If this {@code Class} object represents an interface, the return
3822 * value is an array containing objects representing the uses of interface
3823 * types to specify interfaces directly extended by the interface. The
3824 * order of the objects in the array corresponds to the order of the
3825 * interface types used in the 'extends' clause of the declaration of this
3826 * {@code Class} object.
3827 *
3828 * <p> If this {@code Class} object represents a class or interface whose
3829 * declaration does not explicitly indicate any annotated superinterfaces,
3830 * the return value is an array of length 0.
3831 *
3832 * <p> If this {@code Class} object represents either the {@code Object}
3833 * class, an array type, a primitive type, or void, the return value is an
3834 * array of length 0.
3835 *
3836 * @return an array representing the superinterfaces
3837 * @since 1.8
3838 */
3839 public AnnotatedType[] getAnnotatedInterfaces() {
3840 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3841 }
3842
3843 private native Class<?> getNestHost0();
3844
3845 /**
3846 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3847 * or interface represented by this {@code Class} object belongs.
3848 * Every class and interface belongs to exactly one nest.
3849 *
3850 * If the nest host of this class or interface has previously
3851 * been determined, then this method returns the nest host.
3852 * If the nest host of this class or interface has
3853 * not previously been determined, then this method determines the nest
3854 * host using the algorithm of JVMS 5.4.4, and returns it.
3855 *
3856 * Often, a class or interface belongs to a nest consisting only of itself,
3857 * in which case this method returns {@code this} to indicate that the class
3858 * or interface is the nest host.
3859 *
3860 * <p>If this {@code Class} object represents a primitive type, an array type,
3861 * or {@code void}, then this method returns {@code this},
3862 * indicating that the represented entity belongs to the nest consisting only of
3863 * itself, and is the nest host.
3864 *
3865 * @return the nest host of this class or interface
3866 *
3867 * @since 11
3868 * @jvms 4.7.28 The {@code NestHost} Attribute
3869 * @jvms 4.7.29 The {@code NestMembers} Attribute
3870 * @jvms 5.4.4 Access Control
3871 */
3872 public Class<?> getNestHost() {
3873 if (isPrimitive() || isArray()) {
3874 return this;
3875 }
3876 return getNestHost0();
3877 }
3878
3879 /**
3880 * Determines if the given {@code Class} is a nestmate of the
3881 * class or interface represented by this {@code Class} object.
3882 * Two classes or interfaces are nestmates
3883 * if they have the same {@linkplain #getNestHost() nest host}.
3884 *
3885 * @param c the class to check
3886 * @return {@code true} if this class and {@code c} are members of
3887 * the same nest; and {@code false} otherwise.
3888 *
3889 * @since 11
3890 */
3891 public boolean isNestmateOf(Class<?> c) {
3892 if (this == c) {
3893 return true;
3894 }
3895 if (isPrimitive() || isArray() ||
3896 c.isPrimitive() || c.isArray()) {
3897 return false;
3898 }
3899
3900 return getNestHost() == c.getNestHost();
3901 }
3902
3903 private native Class<?>[] getNestMembers0();
3904
3905 /**
3906 * Returns an array containing {@code Class} objects representing all the
3907 * classes and interfaces that are members of the nest to which the class
3908 * or interface represented by this {@code Class} object belongs.
3909 *
3910 * First, this method obtains the {@linkplain #getNestHost() nest host},
3911 * {@code H}, of the nest to which the class or interface represented by
3912 * this {@code Class} object belongs. The zeroth element of the returned
3913 * array is {@code H}.
3914 *
3915 * Then, for each class or interface {@code C} which is recorded by {@code H}
3916 * as being a member of its nest, this method attempts to obtain the {@code Class}
3917 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3918 * loader} of the current {@code Class} object), and then obtains the
3919 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3920 * The classes and interfaces which are recorded by {@code H} as being members
3921 * of its nest, and for which {@code H} can be determined as their nest host,
3922 * are indicated by subsequent elements of the returned array. The order of
3923 * such elements is unspecified. Duplicates are permitted.
3924 *
3925 * <p>If this {@code Class} object represents a primitive type, an array type,
3926 * or {@code void}, then this method returns a single-element array containing
3927 * {@code this}.
3928 *
3929 * @apiNote
3930 * The returned array includes only the nest members recorded in the {@code NestMembers}
3931 * attribute, and not any hidden classes that were added to the nest via
3932 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3933 * Lookup::defineHiddenClass}.
3934 *
3935 * @return an array of all classes and interfaces in the same nest as
3936 * this class or interface
3937 *
3938 * @since 11
3939 * @see #getNestHost()
3940 * @jvms 4.7.28 The {@code NestHost} Attribute
3941 * @jvms 4.7.29 The {@code NestMembers} Attribute
3942 */
3943 public Class<?>[] getNestMembers() {
3944 if (isPrimitive() || isArray()) {
3945 return new Class<?>[] { this };
3946 }
3947 Class<?>[] members = getNestMembers0();
3948 // Can't actually enable this due to bootstrapping issues
3949 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3950 return members;
3951 }
3952
3953 /**
3954 * Returns the descriptor string of the entity (class, interface, array class,
3955 * primitive type, or {@code void}) represented by this {@code Class} object.
3956 *
3957 * <p> If this {@code Class} object represents a class or interface,
3958 * not an array class, then:
3959 * <ul>
3960 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3961 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3962 * for the class or interface. Calling
3963 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3964 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3965 * describing this class or interface.
3966 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3967 * then the result is a string of the form:
3968 * <blockquote>
3969 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3970 * </blockquote>
3971 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3972 * encoded in internal form indicated by the {@code class} file passed to
3973 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3974 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3975 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3976 * The result string is not a type descriptor.
3977 * </ul>
3978 *
3979 * <p> If this {@code Class} object represents an array class, then
3980 * the result is a string consisting of one or more '{@code [}' characters
3981 * representing the depth of the array nesting, followed by the
3982 * descriptor string of the element type.
3983 * <ul>
3984 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3985 * or interface, then this array class can be described nominally.
3986 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3987 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3988 * describing this array class.
3989 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3990 * interface, then this array class cannot be described nominally.
3991 * The result string is not a type descriptor.
3992 * </ul>
3993 *
3994 * <p> If this {@code Class} object represents a primitive type or
3995 * {@code void}, then the result is a field descriptor string which
3996 * is a one-letter code corresponding to a primitive type or {@code void}
3997 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3998 *
3999 * @return the descriptor string for this {@code Class} object
4000 * @jvms 4.3.2 Field Descriptors
4001 * @since 12
4002 */
4003 @Override
4004 public String descriptorString() {
4005 if (isPrimitive())
4006 return Wrapper.forPrimitiveType(this).basicTypeString();
4007
4008 if (isArray()) {
4009 return "[".concat(componentType.descriptorString());
4010 } else if (isHidden()) {
4011 String name = getName();
4012 int index = name.indexOf('/');
4013 return new StringBuilder(name.length() + 2)
4014 .append('L')
4015 .append(name.substring(0, index).replace('.', '/'))
4016 .append('.')
4017 .append(name, index + 1, name.length())
4018 .append(';')
4019 .toString();
4020 } else {
4021 String name = getName().replace('.', '/');
4022 return StringConcatHelper.concat("L", name, ";");
4023 }
4024 }
4025
4026 /**
4027 * Returns the component type of this {@code Class}, if it describes
4028 * an array type, or {@code null} otherwise.
4029 *
4030 * @implSpec
4031 * Equivalent to {@link Class#getComponentType()}.
4032 *
4033 * @return a {@code Class} describing the component type, or {@code null}
4034 * if this {@code Class} does not describe an array type
4035 * @since 12
4036 */
4037 @Override
4038 public Class<?> componentType() {
4039 return isArray() ? componentType : null;
4040 }
4041
4042 /**
4043 * Returns a {@code Class} for an array type whose component type
4044 * is described by this {@linkplain Class}.
4045 *
4046 * @throws UnsupportedOperationException if this component type is {@linkplain
4047 * Void#TYPE void} or if the number of dimensions of the resulting array
4048 * type would exceed 255.
4049 * @return a {@code Class} describing the array type
4050 * @jvms 4.3.2 Field Descriptors
4051 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4052 * @since 12
4053 */
4054 @Override
4055 public Class<?> arrayType() {
4056 try {
4057 return Array.newInstance(this, 0).getClass();
4058 } catch (IllegalArgumentException iae) {
4059 throw new UnsupportedOperationException(iae);
4060 }
4061 }
4062
4063 /**
4064 * Returns a nominal descriptor for this instance, if one can be
4065 * constructed, or an empty {@link Optional} if one cannot be.
4066 *
4067 * @return An {@link Optional} containing the resulting nominal descriptor,
4068 * or an empty {@link Optional} if one cannot be constructed.
4069 * @since 12
4070 */
4071 @Override
4072 public Optional<ClassDesc> describeConstable() {
4073 Class<?> c = isArray() ? elementType() : this;
4074 return c.isHidden() ? Optional.empty()
4075 : Optional.of(ConstantUtils.classDesc(this));
4076 }
4077
4078 /**
4079 * Returns {@code true} if and only if the underlying class is a hidden class.
4080 *
4081 * @return {@code true} if and only if this class is a hidden class.
4082 *
4083 * @since 15
4084 * @see MethodHandles.Lookup#defineHiddenClass
4085 * @see Class##hiddenClasses Hidden Classes
4086 */
4087 @IntrinsicCandidate
4088 public native boolean isHidden();
4089
4090 /**
4091 * Returns an array containing {@code Class} objects representing the
4092 * direct subinterfaces or subclasses permitted to extend or
4093 * implement this class or interface if it is sealed. The order of such elements
4094 * is unspecified. The array is empty if this sealed class or interface has no
4095 * permitted subclass. If this {@code Class} object represents a primitive type,
4096 * {@code void}, an array type, or a class or interface that is not sealed,
4097 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4098 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4099 * returns a non-null value.
4100 *
4101 * For each class or interface {@code C} which is recorded as a permitted
4102 * direct subinterface or subclass of this class or interface,
4103 * this method attempts to obtain the {@code Class}
4104 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4105 * loader} of the current {@code Class} object).
4106 * The {@code Class} objects which can be obtained and which are direct
4107 * subinterfaces or subclasses of this class or interface,
4108 * are indicated by elements of the returned array. If a {@code Class} object
4109 * cannot be obtained, it is silently ignored, and not included in the result
4110 * array.
4111 *
4112 * @return an array of {@code Class} objects of the permitted subclasses of this class
4113 * or interface, or {@code null} if this class or interface is not sealed.
4114 *
4115 * @jls 8.1 Class Declarations
4116 * @jls 9.1 Interface Declarations
4117 * @since 17
4118 */
4119 public Class<?>[] getPermittedSubclasses() {
4120 Class<?>[] subClasses;
4121 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4122 return null;
4123 }
4124 if (subClasses.length > 0) {
4125 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4126 subClasses = Arrays.stream(subClasses)
4127 .filter(this::isDirectSubType)
4128 .toArray(s -> new Class<?>[s]);
4129 }
4130 }
4131 return subClasses;
4132 }
4133
4134 private boolean isDirectSubType(Class<?> c) {
4135 if (isInterface()) {
4136 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4137 if (i == this) {
4138 return true;
4139 }
4140 }
4141 } else {
4142 return c.getSuperclass() == this;
4143 }
4144 return false;
4145 }
4146
4147 /**
4148 * Returns {@code true} if and only if this {@code Class} object represents
4149 * a sealed class or interface. If this {@code Class} object represents a
4150 * primitive type, {@code void}, or an array type, this method returns
4151 * {@code false}. A sealed class or interface has (possibly zero) permitted
4152 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4153 * possibly empty value for a sealed class or interface.
4154 *
4155 * @return {@code true} if and only if this {@code Class} object represents
4156 * a sealed class or interface.
4157 *
4158 * @jls 8.1 Class Declarations
4159 * @jls 9.1 Interface Declarations
4160 * @since 17
4161 */
4162 public boolean isSealed() {
4163 if (isArray() || isPrimitive()) {
4164 return false;
4165 }
4166 return getPermittedSubclasses() != null;
4167 }
4168
4169 private native Class<?>[] getPermittedSubclasses0();
4170
4171 /*
4172 * Return the class's major and minor class file version packed into an int.
4173 * The high order 16 bits contain the class's minor version. The low order
4174 * 16 bits contain the class's major version.
4175 *
4176 * If the class is an array type then the class file version of its element
4177 * type is returned. If the class is a primitive type then the latest class
4178 * file major version is returned and zero is returned for the minor version.
4179 */
4180 /* package-private */
4181 int getClassFileVersion() {
4182 Class<?> c = isArray() ? elementType() : this;
4183 return c.getClassFileVersion0();
4184 }
4185
4186 private native int getClassFileVersion0();
4187
4188 /*
4189 * Return the access flags as they were in the class's bytecode, including
4190 * the original setting of ACC_SUPER.
4191 *
4192 * If the class is an array type then the access flags of the element type is
4193 * returned. If the class is a primitive then ACC_ABSTRACT | ACC_FINAL | ACC_PUBLIC.
4194 */
4195 private int getClassAccessFlagsRaw() {
4196 Class<?> c = isArray() ? elementType() : this;
4197 return c.getClassAccessFlagsRaw0();
4198 }
4199
4200 private native int getClassAccessFlagsRaw0();
4201 }