1 /*
2 * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.constant.ClassDesc;
30 import java.lang.constant.ConstantDescs;
31 import java.lang.invoke.TypeDescriptor;
32 import java.lang.invoke.MethodHandles;
33 import java.lang.ref.SoftReference;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.ObjectStreamField;
37 import java.lang.reflect.AnnotatedElement;
38 import java.lang.reflect.AnnotatedType;
39 import java.lang.reflect.AccessFlag;
40 import java.lang.reflect.Array;
41 import java.lang.reflect.ClassFileFormatVersion;
42 import java.lang.reflect.Constructor;
43 import java.lang.reflect.Executable;
44 import java.lang.reflect.Field;
45 import java.lang.reflect.GenericArrayType;
46 import java.lang.reflect.GenericDeclaration;
47 import java.lang.reflect.InvocationTargetException;
48 import java.lang.reflect.Member;
49 import java.lang.reflect.Method;
50 import java.lang.reflect.Modifier;
51 import java.lang.reflect.RecordComponent;
52 import java.lang.reflect.Type;
53 import java.lang.reflect.TypeVariable;
54 import java.lang.constant.Constable;
55 import java.net.URL;
56 import java.security.AllPermission;
57 import java.security.Permissions;
58 import java.security.ProtectionDomain;
59 import java.util.ArrayList;
60 import java.util.Arrays;
61 import java.util.Collection;
62 import java.util.HashMap;
63 import java.util.HashSet;
64 import java.util.LinkedHashMap;
65 import java.util.LinkedHashSet;
66 import java.util.List;
67 import java.util.Map;
68 import java.util.Objects;
69 import java.util.Optional;
70 import java.util.Set;
71 import java.util.stream.Collectors;
72
73 import jdk.internal.constant.ConstantUtils;
74 import jdk.internal.javac.PreviewFeature;
75 import jdk.internal.loader.BootLoader;
76 import jdk.internal.loader.BuiltinClassLoader;
77 import jdk.internal.misc.PreviewFeatures;
78 import jdk.internal.misc.Unsafe;
79 import jdk.internal.module.Resources;
80 import jdk.internal.reflect.CallerSensitive;
81 import jdk.internal.reflect.CallerSensitiveAdapter;
82 import jdk.internal.reflect.ConstantPool;
83 import jdk.internal.reflect.Reflection;
84 import jdk.internal.reflect.ReflectionFactory;
85 import jdk.internal.util.ModifiedUtf;
86 import jdk.internal.vm.annotation.AOTRuntimeSetup;
87 import jdk.internal.vm.annotation.AOTSafeClassInitializer;
88 import jdk.internal.vm.annotation.IntrinsicCandidate;
89 import jdk.internal.vm.annotation.Stable;
90
91 import sun.invoke.util.BytecodeDescriptor;
92 import sun.invoke.util.Wrapper;
93 import sun.reflect.generics.factory.CoreReflectionFactory;
94 import sun.reflect.generics.factory.GenericsFactory;
95 import sun.reflect.generics.repository.ClassRepository;
96 import sun.reflect.generics.scope.ClassScope;
97 import sun.reflect.annotation.*;
98
99 /**
100 * Instances of the class {@code Class} represent classes and
101 * interfaces in a running Java application. An enum class and a record
102 * class are kinds of class; an annotation interface is a kind of
103 * interface. Every array also belongs to a class that is reflected as
104 * a {@code Class} object that is shared by all arrays with the same
105 * element type and number of dimensions. The primitive Java types
106 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
107 * int}, {@code long}, {@code float}, and {@code double}), and the
108 * keyword {@code void} are also represented as {@code Class} objects.
109 *
110 * <p> {@code Class} has no public constructor. Instead a {@code Class}
111 * object is constructed automatically by the Java Virtual Machine when
112 * a class is derived from the bytes of a {@code class} file through
113 * the invocation of one of the following methods:
114 * <ul>
115 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
116 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
117 * java.lang.invoke.MethodHandles.Lookup::defineClass}
118 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
119 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
120 * </ul>
121 *
122 * <p> The methods of class {@code Class} expose many characteristics of a
123 * class or interface. Most characteristics are derived from the {@code class}
124 * file that the class loader passed to the Java Virtual Machine or
125 * from the {@code class} file passed to {@code Lookup::defineClass}
126 * or {@code Lookup::defineHiddenClass}.
127 * A few characteristics are determined by the class loading environment
128 * at run time, such as the module returned by {@link #getModule() getModule()}.
129 *
130 * <p> The following example uses a {@code Class} object to print the
131 * class name of an object:
132 *
133 * {@snippet lang="java" :
134 * void printClassName(Object obj) {
135 * System.out.println("The class of " + obj +
136 * " is " + obj.getClass().getName());
137 * }}
138 *
139 * It is also possible to get the {@code Class} object for a named
140 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
141 * (JLS {@jls 15.8.2}).
142 * For example:
143 *
144 * {@snippet lang="java" :
145 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
146 * }
147 *
148 * <p> Some methods of class {@code Class} expose whether the declaration of
149 * a class or interface in Java source code was <em>enclosed</em> within
150 * another declaration. Other methods describe how a class or interface
151 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
152 * classes and interfaces, in the same run-time package, that
153 * allow mutual access to their {@code private} members.
154 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
155 * (JVMS {@jvms 4.7.29}).
156 * One nestmate acts as the
157 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
158 * belong to the nest; each of them in turn records it as the nest host.
159 * The classes and interfaces which belong to a nest, including its host, are
160 * determined when
161 * {@code class} files are generated, for example, a Java compiler
162 * will typically record a top-level class as the host of a nest where the
163 * other members are the classes and interfaces whose declarations are
164 * enclosed within the top-level class declaration.
165 *
166 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
167 * A class or interface created by the invocation of
168 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
169 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
170 * class or interface.
171 * All kinds of class, including enum classes and record classes, may be
172 * hidden classes; all kinds of interface, including annotation interfaces,
173 * may be hidden interfaces.
174 *
175 * The {@linkplain #getName() name of a hidden class or interface} is
176 * not a {@linkplain ClassLoader##binary-name binary name},
177 * which means the following:
178 * <ul>
179 * <li>A hidden class or interface cannot be referenced by the constant pools
180 * of other classes and interfaces.
181 * <li>A hidden class or interface cannot be described in
182 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
183 * {@link #describeConstable() Class::describeConstable},
184 * {@link ClassDesc#of(String) ClassDesc::of}, or
185 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
186 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
187 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
188 * </ul>
189 *
190 * A hidden class or interface is never an array class, but may be
191 * the element type of an array. In all other respects, the fact that
192 * a class or interface is hidden has no bearing on the characteristics
193 * exposed by the methods of class {@code Class}.
194 *
195 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
196 *
197 * Conventionally, a Java compiler, starting from a source file for an
198 * implicitly declared class, say {@code HelloWorld.java}, creates a
199 * similarly-named {@code class} file, {@code HelloWorld.class}, where
200 * the class stored in that {@code class} file is named {@code
201 * "HelloWorld"}, matching the base names of the source and {@code
202 * class} files.
203 *
204 * For the {@code Class} object of an implicitly declared class {@code
205 * HelloWorld}, the methods to get the {@linkplain #getName name} and
206 * {@linkplain #getTypeName type name} return results
207 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
208 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
209 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
210 *
211 * @param <T> the type of the class modeled by this {@code Class}
212 * object. For example, the type of {@code String.class} is {@code
213 * Class<String>}. Use {@code Class<?>} if the class being modeled is
214 * unknown.
215 *
216 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
217 * @since 1.0
218 */
219 @AOTSafeClassInitializer
220 public final class Class<T> implements java.io.Serializable,
221 GenericDeclaration,
222 Type,
223 AnnotatedElement,
224 TypeDescriptor.OfField<Class<?>>,
225 Constable {
226 private static final int ANNOTATION = 0x00002000;
227 private static final int ENUM = 0x00004000;
228 private static final int SYNTHETIC = 0x00001000;
229
230 private static native void registerNatives();
231 static {
232 runtimeSetup();
233 }
234
235 /// No significant static final fields; [#resetArchivedStates()] handles
236 /// prevents storing [#reflectionFactory] into AOT image.
237 @AOTRuntimeSetup
238 private static void runtimeSetup() {
239 registerNatives();
240 }
241
242 /*
243 * Private constructor. Only the Java Virtual Machine creates Class objects.
244 * This constructor is not used and prevents the default constructor being
245 * generated.
246 */
247 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, boolean isIdentity, char flags) {
248 // Initialize final field for classLoader. The initialization value of non-null
249 // prevents future JIT optimizations from assuming this final field is null.
250 // The following assignments are done directly by the VM without calling this constructor.
251 classLoader = loader;
252 componentType = arrayComponentType;
253 modifiers = mods;
254 protectionDomain = pd;
255 primitive = isPrim;
256 identity = isIdentity;
257 classFileAccessFlags = flags;
258 }
259
260 /**
261 * Converts the object to a string. The string representation is the
262 * string "class" or "interface", followed by a space, and then by the
263 * name of the class in the format returned by {@code getName}.
264 * If this {@code Class} object represents a primitive type,
265 * this method returns the name of the primitive type. If
266 * this {@code Class} object represents void this method returns
267 * "void". If this {@code Class} object represents an array type,
268 * this method returns "class " followed by {@code getName}.
269 *
270 * @return a string representation of this {@code Class} object.
271 */
272 public String toString() {
273 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
274 return kind.concat(getName());
275 }
276
277 /**
278 * Returns a string describing this {@code Class}, including
279 * information about modifiers, {@link #isSealed() sealed}/{@code
280 * non-sealed} status, and type parameters.
281 *
282 * The string is formatted as a list of type modifiers, if any,
283 * followed by the kind of type (empty string for primitive types
284 * and {@code class}, {@code enum}, {@code interface},
285 * {@code @interface}, or {@code record} as appropriate), followed
286 * by the type's name, followed by an angle-bracketed
287 * comma-separated list of the type's type parameters, if any,
288 * including informative bounds on the type parameters, if any.
289 *
290 * A space is used to separate modifiers from one another and to
291 * separate any modifiers from the kind of type. The modifiers
292 * occur in canonical order. If there are no type parameters, the
293 * type parameter list is elided.
294 *
295 * For an array type, the string starts with the type name,
296 * followed by an angle-bracketed comma-separated list of the
297 * type's type parameters, if any, followed by a sequence of
298 * {@code []} characters, one set of brackets per dimension of
299 * the array.
300 *
301 * <p>Note that since information about the runtime representation
302 * of a type is being generated, modifiers not present on the
303 * originating source code or illegal on the originating source
304 * code may be present.
305 *
306 * @return a string describing this {@code Class}, including
307 * information about modifiers and type parameters
308 *
309 * @since 1.8
310 */
311 public String toGenericString() {
312 if (isPrimitive()) {
313 return toString();
314 } else {
315 StringBuilder sb = new StringBuilder();
316 Class<?> component = this;
317 int arrayDepth = 0;
318
319 if (isArray()) {
320 do {
321 arrayDepth++;
322 component = component.getComponentType();
323 } while (component.isArray());
324 sb.append(component.getName());
325 } else {
326 // Class modifiers are a superset of interface modifiers
327 int modifiers = getModifiers() & Modifier.classModifiers();
328 // Modifier.toString() below mis-interprets SYNCHRONIZED, STRICT, and VOLATILE bits
329 modifiers &= ~(Modifier.SYNCHRONIZED | Modifier.STRICT | Modifier.VOLATILE);
330 if (modifiers != 0) {
331 sb.append(Modifier.toString(modifiers));
332 sb.append(' ');
333 }
334
335 // A class cannot be strictfp and sealed/non-sealed so
336 // it is sufficient to check for sealed-ness after all
337 // modifiers are printed.
338 addSealingInfo(modifiers, sb);
339
340 if (isAnnotation()) {
341 sb.append('@');
342 }
343 if (isInterface()) { // Note: all annotation interfaces are interfaces
344 sb.append("interface");
345 } else {
346 if (isEnum())
347 sb.append("enum");
348 else {
349 if (isValue()) {
350 sb.append("value ");
351 }
352 if (isRecord())
353 sb.append("record");
354 else
355 sb.append("class");
356 }
357 }
358 sb.append(' ');
359 sb.append(getName());
360 }
361
362 TypeVariable<?>[] typeparms = component.getTypeParameters();
363 if (typeparms.length > 0) {
364 sb.append(Arrays.stream(typeparms)
365 .map(Class::typeVarBounds)
366 .collect(Collectors.joining(",", "<", ">")));
367 }
368
369 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
370
371 return sb.toString();
372 }
373 }
374
375 private void addSealingInfo(int modifiers, StringBuilder sb) {
376 // A class can be final XOR sealed XOR non-sealed.
377 if (Modifier.isFinal(modifiers)) {
378 return; // no-op
379 } else {
380 if (isSealed()) {
381 sb.append("sealed ");
382 return;
383 } else {
384 // Check for sealed ancestor, which implies this class
385 // is non-sealed.
386 if (hasSealedAncestor(this)) {
387 sb.append("non-sealed ");
388 }
389 }
390 }
391 }
392
393 private boolean hasSealedAncestor(Class<?> clazz) {
394 // From JLS 8.1.1.2:
395 // "It is a compile-time error if a class has a sealed direct
396 // superclass or a sealed direct superinterface, and is not
397 // declared final, sealed, or non-sealed either explicitly or
398 // implicitly.
399 // Thus, an effect of the sealed keyword is to force all
400 // direct subclasses to explicitly declare whether they are
401 // final, sealed, or non-sealed. This avoids accidentally
402 // exposing a sealed class hierarchy to unwanted subclassing."
403
404 // Therefore, will just check direct superclass and
405 // superinterfaces.
406 var superclass = clazz.getSuperclass();
407 if (superclass != null && superclass.isSealed()) {
408 return true;
409 }
410 for (var superinterface : clazz.getInterfaces()) {
411 if (superinterface.isSealed()) {
412 return true;
413 }
414 }
415 return false;
416 }
417
418 static String typeVarBounds(TypeVariable<?> typeVar) {
419 Type[] bounds = typeVar.getBounds();
420 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
421 return typeVar.getName();
422 } else {
423 return typeVar.getName() + " extends " +
424 Arrays.stream(bounds)
425 .map(Type::getTypeName)
426 .collect(Collectors.joining(" & "));
427 }
428 }
429
430 /**
431 * Returns the {@code Class} object associated with the class or
432 * interface with the given string name. Invoking this method is
433 * equivalent to:
434 *
435 * {@snippet lang="java" :
436 * Class.forName(className, true, currentLoader)
437 * }
438 *
439 * where {@code currentLoader} denotes the defining class loader of
440 * the current class.
441 *
442 * <p> For example, the following code fragment returns the
443 * runtime {@code Class} object for the class named
444 * {@code java.lang.Thread}:
445 *
446 * {@snippet lang="java" :
447 * Class<?> t = Class.forName("java.lang.Thread");
448 * }
449 * <p>
450 * A call to {@code forName("X")} causes the class named
451 * {@code X} to be initialized.
452 *
453 * <p>
454 * In cases where this method is called from a context where there is no
455 * caller frame on the stack (e.g. when called directly from a JNI
456 * attached thread), the system class loader is used.
457 *
458 * @param className the {@linkplain ClassLoader##binary-name binary name}
459 * of the class or the string representing an array type
460 * @return the {@code Class} object for the class with the
461 * specified name.
462 * @throws LinkageError if the linkage fails
463 * @throws ExceptionInInitializerError if the initialization provoked
464 * by this method fails
465 * @throws ClassNotFoundException if the class cannot be located
466 *
467 * @jls 12.2 Loading of Classes and Interfaces
468 * @jls 12.3 Linking of Classes and Interfaces
469 * @jls 12.4 Initialization of Classes and Interfaces
470 */
471 @CallerSensitive
472 public static Class<?> forName(String className)
473 throws ClassNotFoundException {
474 Class<?> caller = Reflection.getCallerClass();
475 return forName(className, caller);
476 }
477
478 // Caller-sensitive adapter method for reflective invocation
479 @CallerSensitiveAdapter
480 private static Class<?> forName(String className, Class<?> caller)
481 throws ClassNotFoundException {
482 validateClassNameLength(className);
483 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
484 : ClassLoader.getClassLoader(caller);
485 return forName0(className, true, loader);
486 }
487
488 /**
489 * Returns the {@code Class} object associated with the class or
490 * interface with the given string name, using the given class loader.
491 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
492 * this method attempts to locate and load the class or interface. The specified
493 * class loader is used to load the class or interface. If the parameter
494 * {@code loader} is {@code null}, the class is loaded through the bootstrap
495 * class loader. The class is initialized only if the
496 * {@code initialize} parameter is {@code true} and if it has
497 * not been initialized earlier.
498 *
499 * <p> This method cannot be used to obtain any of the {@code Class} objects
500 * representing primitive types or void, hidden classes or interfaces,
501 * or array classes whose element type is a hidden class or interface.
502 * If {@code name} denotes a primitive type or void, for example {@code I},
503 * an attempt will be made to locate a user-defined class in the unnamed package
504 * whose name is {@code I} instead.
505 * To obtain a {@code Class} object for a named primitive type
506 * such as {@code int} or {@code long} use {@link
507 * #forPrimitiveName(String)}.
508 *
509 * <p> To obtain the {@code Class} object associated with an array class,
510 * the name consists of one or more {@code '['} representing the depth
511 * of the array nesting, followed by the element type as encoded in
512 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
513 *
514 * <p> Examples:
515 * {@snippet lang="java" :
516 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
517 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
518 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
519 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
520 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
521 * }
522 *
523 * <p> A call to {@code getName()} on the {@code Class} object returned
524 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
525 *
526 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
527 * named <i>N</i> to be loaded but not initialized regardless of the value
528 * of the {@code initialize} parameter.
529 *
530 * @apiNote
531 * This method throws errors related to loading, linking or initializing
532 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
533 * <cite>The Java Language Specification</cite>.
534 * In addition, this method does not check whether the requested class
535 * is accessible to its caller.
536 *
537 * @param name the {@linkplain ClassLoader##binary-name binary name}
538 * of the class or the string representing an array class
539 *
540 * @param initialize if {@code true} the class will be initialized
541 * (which implies linking). See Section {@jls
542 * 12.4} of <cite>The Java Language
543 * Specification</cite>.
544 * @param loader class loader from which the class must be loaded
545 * @return class object representing the desired class
546 *
547 * @throws LinkageError if the linkage fails
548 * @throws ExceptionInInitializerError if the initialization provoked
549 * by this method fails
550 * @throws ClassNotFoundException if the class cannot be located by
551 * the specified class loader
552 *
553 * @see java.lang.Class#forName(String)
554 * @see java.lang.ClassLoader
555 *
556 * @jls 12.2 Loading of Classes and Interfaces
557 * @jls 12.3 Linking of Classes and Interfaces
558 * @jls 12.4 Initialization of Classes and Interfaces
559 * @jls 13.1 The Form of a Binary
560 * @since 1.2
561 */
562 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
563 throws ClassNotFoundException
564 {
565 validateClassNameLength(name);
566 return forName0(name, initialize, loader);
567 }
568
569 /** Called after security check for system loader access checks have been made. */
570 private static native Class<?> forName0(String name, boolean initialize,
571 ClassLoader loader)
572 throws ClassNotFoundException;
573
574
575 /**
576 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
577 * binary name} in the given module.
578 *
579 * <p> This method attempts to locate and load the class or interface.
580 * It does not link the class, and does not run the class initializer.
581 * If the class is not found, this method returns {@code null}. </p>
582 *
583 * <p> If the class loader of the given module defines other modules and
584 * the given name is a class defined in a different module, this method
585 * returns {@code null} after the class is loaded. </p>
586 *
587 * <p> This method does not check whether the requested class is
588 * accessible to its caller. </p>
589 *
590 * @apiNote
591 * This method does not support loading of array types, unlike
592 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
593 * a binary name. This method returns {@code null} on failure rather than
594 * throwing a {@link ClassNotFoundException}, as is done by
595 * the {@link #forName(String, boolean, ClassLoader)} method.
596 *
597 * @param module A module
598 * @param name The {@linkplain ClassLoader##binary-name binary name}
599 * of the class
600 * @return {@code Class} object of the given name defined in the given module;
601 * {@code null} if not found.
602 *
603 * @throws NullPointerException if the given module or name is {@code null}
604 *
605 * @throws LinkageError if the linkage fails
606 *
607 * @jls 12.2 Loading of Classes and Interfaces
608 * @jls 12.3 Linking of Classes and Interfaces
609 * @since 9
610 */
611 public static Class<?> forName(Module module, String name) {
612 Objects.requireNonNull(module);
613 Objects.requireNonNull(name);
614 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
615 return null;
616 }
617
618 ClassLoader cl = module.getClassLoader();
619 if (cl != null) {
620 return cl.loadClass(module, name);
621 } else {
622 return BootLoader.loadClass(module, name);
623 }
624 }
625
626 /**
627 * {@return {@code true} if this {@code Class} object represents an identity class,
628 * otherwise {@code false}}
629 *
630 * <ul>
631 * <li>
632 * If this {@code Class} object represents an array type this method returns {@code true}.
633 * <li>
634 * If this {@code Class} object represents an interface, a primitive type,
635 * or {@code void} this method returns {@code false}.
636 * <li>
637 * For all other {@code Class} objects, this method returns {@code true} if either
638 * preview features are disabled or {@linkplain Modifier#IDENTITY} is set in the
639 * {@linkplain #getModifiers() class modifiers}.
640 * </ul>
641 * @see AccessFlag#IDENTITY
642 * @since Valhalla
643 */
644 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true)
645 public boolean isIdentity() {
646 return identity;
647 }
648
649 /**
650 * {@return {@code true} if this {@code Class} object represents a value class,
651 * otherwise {@code false}}
652 * <ul>
653 * <li>
654 * If this {@code Class} object represents an array type this method returns {@code false}.
655 * <li>
656 * If this {@code Class} object represents an interface, a primitive type,
657 * or {@code void} this method returns {@code true} only if preview features are enabled.
658 * <li>
659 * For all other {@code Class} objects, this method returns {@code true} only if
660 * preview features are enabled and {@linkplain Modifier#IDENTITY} is not set in the
661 * {@linkplain #getModifiers() class modifiers}.
662 * </ul>
663 * @see AccessFlag#IDENTITY
664 * @since Valhalla
665 */
666 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true)
667 public boolean isValue() {
668 if (!PreviewFeatures.isEnabled()) {
669 return false;
670 }
671 return !isIdentity();
672 }
673
674 /**
675 * {@return the {@code Class} object associated with the
676 * {@linkplain #isPrimitive() primitive type} of the given name}
677 * If the argument is not the name of a primitive type, {@code
678 * null} is returned.
679 *
680 * @param primitiveName the name of the primitive type to find
681 *
682 * @throws NullPointerException if the argument is {@code null}
683 *
684 * @jls 4.2 Primitive Types and Values
685 * @jls 15.8.2 Class Literals
686 * @since 22
687 */
688 public static Class<?> forPrimitiveName(String primitiveName) {
689 return switch(primitiveName) {
690 // Integral types
691 case "int" -> int.class;
692 case "long" -> long.class;
693 case "short" -> short.class;
694 case "char" -> char.class;
695 case "byte" -> byte.class;
696
697 // Floating-point types
698 case "float" -> float.class;
699 case "double" -> double.class;
700
701 // Other types
702 case "boolean" -> boolean.class;
703 case "void" -> void.class;
704
705 default -> null;
706 };
707 }
708
709 /**
710 * Creates a new instance of the class represented by this {@code Class}
711 * object. The class is instantiated as if by a {@code new}
712 * expression with an empty argument list. The class is initialized if it
713 * has not already been initialized.
714 *
715 * @deprecated This method propagates any exception thrown by the
716 * nullary constructor, including a checked exception. Use of
717 * this method effectively bypasses the compile-time exception
718 * checking that would otherwise be performed by the compiler.
719 * The {@link
720 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
721 * Constructor.newInstance} method avoids this problem by wrapping
722 * any exception thrown by the constructor in a (checked) {@link
723 * java.lang.reflect.InvocationTargetException}.
724 *
725 * <p>The call
726 *
727 * {@snippet lang="java" :
728 * clazz.newInstance()
729 * }
730 *
731 * can be replaced by
732 *
733 * {@snippet lang="java" :
734 * clazz.getDeclaredConstructor().newInstance()
735 * }
736 *
737 * The latter sequence of calls is inferred to be able to throw
738 * the additional exception types {@link
739 * InvocationTargetException} and {@link
740 * NoSuchMethodException}. Both of these exception types are
741 * subclasses of {@link ReflectiveOperationException}.
742 *
743 * @return a newly allocated instance of the class represented by this
744 * object.
745 * @throws IllegalAccessException if the class or its nullary
746 * constructor is not accessible.
747 * @throws InstantiationException
748 * if this {@code Class} represents an abstract class,
749 * an interface, an array class, a primitive type, or void;
750 * or if the class has no nullary constructor;
751 * or if the instantiation fails for some other reason.
752 * @throws ExceptionInInitializerError if the initialization
753 * provoked by this method fails.
754 */
755 @CallerSensitive
756 @Deprecated(since="9")
757 public T newInstance()
758 throws InstantiationException, IllegalAccessException
759 {
760 // Constructor lookup
761 Constructor<T> tmpConstructor = cachedConstructor;
762 if (tmpConstructor == null) {
763 if (this == Class.class) {
764 throw new IllegalAccessException(
765 "Can not call newInstance() on the Class for java.lang.Class"
766 );
767 }
768 try {
769 Class<?>[] empty = {};
770 final Constructor<T> c = getReflectionFactory().copyConstructor(
771 getConstructor0(empty, Member.DECLARED));
772 // Disable accessibility checks on the constructor
773 // access check is done with the true caller
774 c.setAccessible(true);
775 cachedConstructor = tmpConstructor = c;
776 } catch (NoSuchMethodException e) {
777 throw (InstantiationException)
778 new InstantiationException(getName()).initCause(e);
779 }
780 }
781
782 try {
783 Class<?> caller = Reflection.getCallerClass();
784 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
785 } catch (InvocationTargetException e) {
786 Unsafe.getUnsafe().throwException(e.getTargetException());
787 // Not reached
788 return null;
789 }
790 }
791
792 private transient volatile Constructor<T> cachedConstructor;
793
794 /**
795 * Determines if the specified {@code Object} is assignment-compatible
796 * with the object represented by this {@code Class}. This method is
797 * the dynamic equivalent of the Java language {@code instanceof}
798 * operator. The method returns {@code true} if the specified
799 * {@code Object} argument is non-null and can be cast to the
800 * reference type represented by this {@code Class} object without
801 * raising a {@code ClassCastException.} It returns {@code false}
802 * otherwise.
803 *
804 * <p> Specifically, if this {@code Class} object represents a
805 * declared class, this method returns {@code true} if the specified
806 * {@code Object} argument is an instance of the represented class (or
807 * of any of its subclasses); it returns {@code false} otherwise. If
808 * this {@code Class} object represents an array class, this method
809 * returns {@code true} if the specified {@code Object} argument
810 * can be converted to an object of the array class by an identity
811 * conversion or by a widening reference conversion; it returns
812 * {@code false} otherwise. If this {@code Class} object
813 * represents an interface, this method returns {@code true} if the
814 * class or any superclass of the specified {@code Object} argument
815 * implements this interface; it returns {@code false} otherwise. If
816 * this {@code Class} object represents a primitive type, this method
817 * returns {@code false}.
818 *
819 * @param obj the object to check
820 * @return true if {@code obj} is an instance of this class
821 *
822 * @since 1.1
823 */
824 @IntrinsicCandidate
825 public native boolean isInstance(Object obj);
826
827
828 /**
829 * Determines if the class or interface represented by this
830 * {@code Class} object is either the same as, or is a superclass or
831 * superinterface of, the class or interface represented by the specified
832 * {@code Class} parameter. It returns {@code true} if so;
833 * otherwise it returns {@code false}. If this {@code Class}
834 * object represents a primitive type, this method returns
835 * {@code true} if the specified {@code Class} parameter is
836 * exactly this {@code Class} object; otherwise it returns
837 * {@code false}.
838 *
839 * <p> Specifically, this method tests whether the type represented by the
840 * specified {@code Class} parameter can be converted to the type
841 * represented by this {@code Class} object via an identity conversion
842 * or via a widening reference conversion. See <cite>The Java Language
843 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
844 * for details.
845 *
846 * @param cls the {@code Class} object to be checked
847 * @return the {@code boolean} value indicating whether objects of the
848 * type {@code cls} can be assigned to objects of this class
849 * @throws NullPointerException if the specified Class parameter is
850 * null.
851 * @since 1.1
852 */
853 @IntrinsicCandidate
854 public native boolean isAssignableFrom(Class<?> cls);
855
856
857 /**
858 * Determines if this {@code Class} object represents an
859 * interface type.
860 *
861 * @return {@code true} if this {@code Class} object represents an interface;
862 * {@code false} otherwise.
863 */
864 public boolean isInterface() {
865 return Modifier.isInterface(modifiers);
866 }
867
868
869 /**
870 * Determines if this {@code Class} object represents an array class.
871 *
872 * @return {@code true} if this {@code Class} object represents an array class;
873 * {@code false} otherwise.
874 * @since 1.1
875 */
876 public boolean isArray() {
877 return componentType != null;
878 }
879
880
881 /**
882 * Determines if this {@code Class} object represents a primitive
883 * type or void.
884 *
885 * <p> There are nine predefined {@code Class} objects to
886 * represent the eight primitive types and void. These are
887 * created by the Java Virtual Machine, and have the same
888 * {@linkplain #getName() names} as the primitive types that they
889 * represent, namely {@code boolean}, {@code byte}, {@code char},
890 * {@code short}, {@code int}, {@code long}, {@code float}, and
891 * {@code double}.
892 *
893 * <p>No other class objects are considered primitive.
894 *
895 * @apiNote
896 * A {@code Class} object represented by a primitive type can be
897 * accessed via the {@code TYPE} public static final variables
898 * defined in the primitive wrapper classes such as {@link
899 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
900 * language, the objects may be referred to by a class literal
901 * expression such as {@code int.class}. The {@code Class} object
902 * for void can be expressed as {@code void.class} or {@link
903 * java.lang.Void#TYPE Void.TYPE}.
904 *
905 * @return true if and only if this class represents a primitive type
906 *
907 * @see java.lang.Boolean#TYPE
908 * @see java.lang.Character#TYPE
909 * @see java.lang.Byte#TYPE
910 * @see java.lang.Short#TYPE
911 * @see java.lang.Integer#TYPE
912 * @see java.lang.Long#TYPE
913 * @see java.lang.Float#TYPE
914 * @see java.lang.Double#TYPE
915 * @see java.lang.Void#TYPE
916 * @since 1.1
917 * @jls 15.8.2 Class Literals
918 */
919 public boolean isPrimitive() {
920 return primitive;
921 }
922
923 /**
924 * Returns true if this {@code Class} object represents an annotation
925 * interface. Note that if this method returns true, {@link #isInterface()}
926 * would also return true, as all annotation interfaces are also interfaces.
927 *
928 * @return {@code true} if this {@code Class} object represents an annotation
929 * interface; {@code false} otherwise
930 * @since 1.5
931 */
932 public boolean isAnnotation() {
933 return (getModifiers() & ANNOTATION) != 0;
934 }
935
936 /**
937 *{@return {@code true} if and only if this class has the synthetic modifier
938 * bit set}
939 *
940 * @jls 13.1 The Form of a Binary
941 * @jvms 4.1 The {@code ClassFile} Structure
942 * @see <a
943 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
944 * programming language and JVM modeling in core reflection</a>
945 * @since 1.5
946 */
947 public boolean isSynthetic() {
948 return (getModifiers() & SYNTHETIC) != 0;
949 }
950
951 /**
952 * Returns the name of the entity (class, interface, array class,
953 * primitive type, or void) represented by this {@code Class} object.
954 *
955 * <p> If this {@code Class} object represents a class or interface,
956 * not an array class, then:
957 * <ul>
958 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
959 * then the {@linkplain ClassLoader##binary-name binary name}
960 * of the class or interface is returned.
961 * <li> If the class or interface is hidden, then the result is a string
962 * of the form: {@code N + '/' + <suffix>}
963 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
964 * indicated by the {@code class} file passed to
965 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
966 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
967 * </ul>
968 *
969 * <p> If this {@code Class} object represents an array class, then
970 * the result is a string consisting of one or more '{@code [}' characters
971 * representing the depth of the array nesting, followed by the element
972 * type as encoded using the following table:
973 *
974 * <blockquote><table class="striped" id="nameFormat">
975 * <caption style="display:none">Element types and encodings</caption>
976 * <thead>
977 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
978 * </thead>
979 * <tbody style="text-align:left">
980 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
981 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
982 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
983 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
984 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
985 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
986 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
987 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
988 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
989 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
990 * </tbody>
991 * </table></blockquote>
992 *
993 * <p> If this {@code Class} object represents a primitive type or {@code void},
994 * then the result is a string with the same spelling as the Java language
995 * keyword which corresponds to the primitive type or {@code void}.
996 *
997 * <p> Examples:
998 * <blockquote><pre>
999 * String.class.getName()
1000 * returns "java.lang.String"
1001 * Character.UnicodeBlock.class.getName()
1002 * returns "java.lang.Character$UnicodeBlock"
1003 * byte.class.getName()
1004 * returns "byte"
1005 * (new Object[3]).getClass().getName()
1006 * returns "[Ljava.lang.Object;"
1007 * (new int[3][4][5][6][7][8][9]).getClass().getName()
1008 * returns "[[[[[[[I"
1009 * </pre></blockquote>
1010 *
1011 * @apiNote
1012 * Distinct class objects can have the same name but different class loaders.
1013 *
1014 * @return the name of the class, interface, or other entity
1015 * represented by this {@code Class} object.
1016 * @jls 13.1 The Form of a Binary
1017 */
1018 public String getName() {
1019 String name = this.name;
1020 return name != null ? name : initClassName();
1021 }
1022
1023 // Cache the name to reduce the number of calls into the VM.
1024 // This field would be set by VM itself during initClassName call.
1025 private transient String name;
1026 private native String initClassName();
1027
1028 /**
1029 * Returns the class loader for the class. Some implementations may use
1030 * null to represent the bootstrap class loader. This method will return
1031 * null in such implementations if this class was loaded by the bootstrap
1032 * class loader.
1033 *
1034 * <p>If this {@code Class} object
1035 * represents a primitive type or void, null is returned.
1036 *
1037 * @return the class loader that loaded the class or interface
1038 * represented by this {@code Class} object.
1039 * @see java.lang.ClassLoader
1040 */
1041 public ClassLoader getClassLoader() {
1042 return classLoader;
1043 }
1044
1045 // Package-private to allow ClassLoader access
1046 ClassLoader getClassLoader0() { return classLoader; }
1047
1048 /**
1049 * Returns the module that this class or interface is a member of.
1050 *
1051 * If this class represents an array type then this method returns the
1052 * {@code Module} for the element type. If this class represents a
1053 * primitive type or void, then the {@code Module} object for the
1054 * {@code java.base} module is returned.
1055 *
1056 * If this class is in an unnamed module then the {@linkplain
1057 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1058 * loader for this class is returned.
1059 *
1060 * @return the module that this class or interface is a member of
1061 *
1062 * @since 9
1063 */
1064 public Module getModule() {
1065 return module;
1066 }
1067
1068 // set by VM
1069 @Stable
1070 private transient Module module;
1071
1072 // Initialized in JVM not by private constructor
1073 // This field is filtered from reflection access, i.e. getDeclaredField
1074 // will throw NoSuchFieldException
1075 private final ClassLoader classLoader;
1076
1077 private transient Object classData; // Set by VM
1078 private transient Object[] signers; // Read by VM, mutable
1079 private final transient char modifiers; // Set by the VM
1080 private final transient char classFileAccessFlags; // Set by the VM
1081 private final transient boolean primitive; // Set by the VM if the Class is a primitive type
1082 private final transient boolean identity; // Set by the VM if the Class is an identity class
1083
1084 // package-private
1085 Object getClassData() {
1086 return classData;
1087 }
1088
1089 /**
1090 * Returns an array of {@code TypeVariable} objects that represent the
1091 * type variables declared by the generic declaration represented by this
1092 * {@code GenericDeclaration} object, in declaration order. Returns an
1093 * array of length 0 if the underlying generic declaration declares no type
1094 * variables.
1095 *
1096 * @return an array of {@code TypeVariable} objects that represent
1097 * the type variables declared by this generic declaration
1098 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1099 * signature of this generic declaration does not conform to
1100 * the format specified in section {@jvms 4.7.9} of
1101 * <cite>The Java Virtual Machine Specification</cite>
1102 * @since 1.5
1103 */
1104 @SuppressWarnings("unchecked")
1105 public TypeVariable<Class<T>>[] getTypeParameters() {
1106 ClassRepository info = getGenericInfo();
1107 if (info != null)
1108 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1109 else
1110 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1111 }
1112
1113
1114 /**
1115 * Returns the {@code Class} representing the direct superclass of the
1116 * entity (class, interface, primitive type or void) represented by
1117 * this {@code Class}. If this {@code Class} represents either the
1118 * {@code Object} class, an interface, a primitive type, or void, then
1119 * null is returned. If this {@code Class} object represents an array class
1120 * then the {@code Class} object representing the {@code Object} class is
1121 * returned.
1122 *
1123 * @return the direct superclass of the class represented by this {@code Class} object
1124 */
1125 @IntrinsicCandidate
1126 public native Class<? super T> getSuperclass();
1127
1128
1129 /**
1130 * Returns the {@code Type} representing the direct superclass of
1131 * the entity (class, interface, primitive type or void) represented by
1132 * this {@code Class} object.
1133 *
1134 * <p>If the superclass is a parameterized type, the {@code Type}
1135 * object returned must accurately reflect the actual type
1136 * arguments used in the source code. The parameterized type
1137 * representing the superclass is created if it had not been
1138 * created before. See the declaration of {@link
1139 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1140 * semantics of the creation process for parameterized types. If
1141 * this {@code Class} object represents either the {@code Object}
1142 * class, an interface, a primitive type, or void, then null is
1143 * returned. If this {@code Class} object represents an array class
1144 * then the {@code Class} object representing the {@code Object} class is
1145 * returned.
1146 *
1147 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1148 * class signature does not conform to the format specified in
1149 * section {@jvms 4.7.9} of <cite>The Java Virtual
1150 * Machine Specification</cite>
1151 * @throws TypeNotPresentException if the generic superclass
1152 * refers to a non-existent type declaration
1153 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1154 * generic superclass refers to a parameterized type that cannot be
1155 * instantiated for any reason
1156 * @return the direct superclass of the class represented by this {@code Class} object
1157 * @since 1.5
1158 */
1159 public Type getGenericSuperclass() {
1160 ClassRepository info = getGenericInfo();
1161 if (info == null) {
1162 return getSuperclass();
1163 }
1164
1165 // Historical irregularity:
1166 // Generic signature marks interfaces with superclass = Object
1167 // but this API returns null for interfaces
1168 if (isInterface()) {
1169 return null;
1170 }
1171
1172 return info.getSuperclass();
1173 }
1174
1175 /**
1176 * Gets the package of this class.
1177 *
1178 * <p>If this class represents an array type, a primitive type or void,
1179 * this method returns {@code null}.
1180 *
1181 * @return the package of this class.
1182 */
1183 public Package getPackage() {
1184 if (isPrimitive() || isArray()) {
1185 return null;
1186 }
1187 ClassLoader cl = classLoader;
1188 return cl != null ? cl.definePackage(this)
1189 : BootLoader.definePackage(this);
1190 }
1191
1192 /**
1193 * Returns the fully qualified package name.
1194 *
1195 * <p> If this class is a top level class, then this method returns the fully
1196 * qualified name of the package that the class is a member of, or the
1197 * empty string if the class is in an unnamed package.
1198 *
1199 * <p> If this class is a member class, then this method is equivalent to
1200 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1201 * enclosing class}.
1202 *
1203 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1204 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1205 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1206 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1207 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1208 *
1209 * <p> If this class represents an array type then this method returns the
1210 * package name of the element type. If this class represents a primitive
1211 * type or void then the package name "{@code java.lang}" is returned.
1212 *
1213 * @return the fully qualified package name
1214 *
1215 * @since 9
1216 * @jls 6.7 Fully Qualified Names and Canonical Names
1217 */
1218 public String getPackageName() {
1219 String pn = this.packageName;
1220 if (pn == null) {
1221 Class<?> c = isArray() ? elementType() : this;
1222 if (c.isPrimitive()) {
1223 pn = "java.lang";
1224 } else {
1225 String cn = c.getName();
1226 int dot = cn.lastIndexOf('.');
1227 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1228 }
1229 this.packageName = pn;
1230 }
1231 return pn;
1232 }
1233
1234 // cached package name
1235 private transient String packageName;
1236
1237 /**
1238 * Returns the interfaces directly implemented by the class or interface
1239 * represented by this {@code Class} object.
1240 *
1241 * <p>If this {@code Class} object represents a class, the return value is an array
1242 * containing objects representing all interfaces directly implemented by
1243 * the class. The order of the interface objects in the array corresponds
1244 * to the order of the interface names in the {@code implements} clause of
1245 * the declaration of the class represented by this {@code Class} object. For example,
1246 * given the declaration:
1247 * <blockquote>
1248 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1249 * </blockquote>
1250 * suppose the value of {@code s} is an instance of
1251 * {@code Shimmer}; the value of the expression:
1252 * <blockquote>
1253 * {@code s.getClass().getInterfaces()[0]}
1254 * </blockquote>
1255 * is the {@code Class} object that represents interface
1256 * {@code FloorWax}; and the value of:
1257 * <blockquote>
1258 * {@code s.getClass().getInterfaces()[1]}
1259 * </blockquote>
1260 * is the {@code Class} object that represents interface
1261 * {@code DessertTopping}.
1262 *
1263 * <p>If this {@code Class} object represents an interface, the array contains objects
1264 * representing all interfaces directly extended by the interface. The
1265 * order of the interface objects in the array corresponds to the order of
1266 * the interface names in the {@code extends} clause of the declaration of
1267 * the interface represented by this {@code Class} object.
1268 *
1269 * <p>If this {@code Class} object represents a class or interface that implements no
1270 * interfaces, the method returns an array of length 0.
1271 *
1272 * <p>If this {@code Class} object represents a primitive type or void, the method
1273 * returns an array of length 0.
1274 *
1275 * <p>If this {@code Class} object represents an array type, the
1276 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1277 * returned in that order.
1278 *
1279 * @return an array of interfaces directly implemented by this class
1280 */
1281 public Class<?>[] getInterfaces() {
1282 // defensively copy before handing over to user code
1283 return getInterfaces(true);
1284 }
1285
1286 private Class<?>[] getInterfaces(boolean cloneArray) {
1287 ReflectionData<T> rd = reflectionData();
1288 Class<?>[] interfaces = rd.interfaces;
1289 if (interfaces == null) {
1290 interfaces = getInterfaces0();
1291 rd.interfaces = interfaces;
1292 }
1293 // defensively copy if requested
1294 return cloneArray ? interfaces.clone() : interfaces;
1295 }
1296
1297 private native Class<?>[] getInterfaces0();
1298
1299 /**
1300 * Returns the {@code Type}s representing the interfaces
1301 * directly implemented by the class or interface represented by
1302 * this {@code Class} object.
1303 *
1304 * <p>If a superinterface is a parameterized type, the
1305 * {@code Type} object returned for it must accurately reflect
1306 * the actual type arguments used in the source code. The
1307 * parameterized type representing each superinterface is created
1308 * if it had not been created before. See the declaration of
1309 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1310 * for the semantics of the creation process for parameterized
1311 * types.
1312 *
1313 * <p>If this {@code Class} object represents a class, the return value is an array
1314 * containing objects representing all interfaces directly implemented by
1315 * the class. The order of the interface objects in the array corresponds
1316 * to the order of the interface names in the {@code implements} clause of
1317 * the declaration of the class represented by this {@code Class} object.
1318 *
1319 * <p>If this {@code Class} object represents an interface, the array contains objects
1320 * representing all interfaces directly extended by the interface. The
1321 * order of the interface objects in the array corresponds to the order of
1322 * the interface names in the {@code extends} clause of the declaration of
1323 * the interface represented by this {@code Class} object.
1324 *
1325 * <p>If this {@code Class} object represents a class or interface that implements no
1326 * interfaces, the method returns an array of length 0.
1327 *
1328 * <p>If this {@code Class} object represents a primitive type or void, the method
1329 * returns an array of length 0.
1330 *
1331 * <p>If this {@code Class} object represents an array type, the
1332 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1333 * returned in that order.
1334 *
1335 * @throws java.lang.reflect.GenericSignatureFormatError
1336 * if the generic class signature does not conform to the
1337 * format specified in section {@jvms 4.7.9} of <cite>The
1338 * Java Virtual Machine Specification</cite>
1339 * @throws TypeNotPresentException if any of the generic
1340 * superinterfaces refers to a non-existent type declaration
1341 * @throws java.lang.reflect.MalformedParameterizedTypeException
1342 * if any of the generic superinterfaces refer to a parameterized
1343 * type that cannot be instantiated for any reason
1344 * @return an array of interfaces directly implemented by this class
1345 * @since 1.5
1346 */
1347 public Type[] getGenericInterfaces() {
1348 ClassRepository info = getGenericInfo();
1349 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1350 }
1351
1352
1353 /**
1354 * Returns the {@code Class} representing the component type of an
1355 * array. If this class does not represent an array class this method
1356 * returns null.
1357 *
1358 * @return the {@code Class} representing the component type of this
1359 * class if this class is an array
1360 * @see java.lang.reflect.Array
1361 * @since 1.1
1362 */
1363 public Class<?> getComponentType() {
1364 return componentType;
1365 }
1366
1367 // The componentType field's null value is the sole indication that the class
1368 // is an array - see isArray().
1369 private transient final Class<?> componentType;
1370
1371 /*
1372 * Returns the {@code Class} representing the element type of an array class.
1373 * If this class does not represent an array class, then this method returns
1374 * {@code null}.
1375 */
1376 private Class<?> elementType() {
1377 if (!isArray()) return null;
1378
1379 Class<?> c = this;
1380 while (c.isArray()) {
1381 c = c.getComponentType();
1382 }
1383 return c;
1384 }
1385
1386 /**
1387 * Returns the Java language modifiers for this class or interface, encoded
1388 * in an integer. The modifiers consist of the Java Virtual Machine's
1389 * constants for {@code public}, {@code protected},
1390 * {@code private}, {@code final}, {@code static},
1391 * {@code abstract} and {@code interface}; they should be decoded
1392 * using the methods of class {@code Modifier}.
1393 *
1394 * <p> If the underlying class is an array class:
1395 * <ul>
1396 * <li> its {@code public}, {@code private} and {@code protected}
1397 * modifiers are the same as those of its component type
1398 * <li> its {@code abstract} and {@code final} modifiers are always
1399 * {@code true}
1400 * <li> its interface modifier is always {@code false}, even when
1401 * the component type is an interface
1402 * <li> its {@code identity} modifier is always true
1403 * </ul>
1404 * If this {@code Class} object represents a primitive type or
1405 * void, its {@code public}, {@code abstract}, and {@code final}
1406 * modifiers are always {@code true}.
1407 * For {@code Class} objects representing void, primitive types, and
1408 * arrays, the values of other modifiers are {@code false} other
1409 * than as specified above.
1410 *
1411 * <p> The modifier encodings are defined in section {@jvms 4.1}
1412 * of <cite>The Java Virtual Machine Specification</cite>.
1413 *
1414 * @return the {@code int} representing the modifiers for this class
1415 * @see java.lang.reflect.Modifier
1416 * @see #accessFlags()
1417 * @see <a
1418 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1419 * programming language and JVM modeling in core reflection</a>
1420 * @since 1.1
1421 * @jls 8.1.1 Class Modifiers
1422 * @jls 9.1.1 Interface Modifiers
1423 * @jvms 4.1 The {@code ClassFile} Structure
1424 */
1425 public int getModifiers() { return modifiers; }
1426
1427 /**
1428 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1429 * flags} for this class, possibly empty}
1430 * The {@code AccessFlags} may depend on the class file format version of the class.
1431 *
1432 * <p> If the underlying class is an array class:
1433 * <ul>
1434 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1435 * access flags are the same as those of its component type
1436 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1437 * <li> its {@code INTERFACE} flag is absent, even when the
1438 * component type is an interface
1439 * <li> its {@code identity} modifier is always true
1440 * </ul>
1441 * If this {@code Class} object represents a primitive type or
1442 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1443 * {@code FINAL}.
1444 * For {@code Class} objects representing void, primitive types, and
1445 * arrays, access flags are absent other than as specified above.
1446 *
1447 * @see #getModifiers()
1448 * @jvms 4.1 The ClassFile Structure
1449 * @jvms 4.7.6 The InnerClasses Attribute
1450 * @since 20
1451 */
1452 public Set<AccessFlag> accessFlags() {
1453 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1454 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1455 // and STATIC, which are not allowed on Location.CLASS.
1456 // Use getClassFileAccessFlags to expose SUPER status.
1457 // Arrays need to use PRIVATE/PROTECTED from its component modifiers.
1458 var location = (isMemberClass() || isLocalClass() ||
1459 isAnonymousClass() || isArray()) ?
1460 AccessFlag.Location.INNER_CLASS :
1461 AccessFlag.Location.CLASS;
1462 int accessFlags = location == AccessFlag.Location.CLASS ? getClassFileAccessFlags() : getModifiers();
1463 var reflectionFactory = getReflectionFactory();
1464 var ans = reflectionFactory.parseAccessFlags(accessFlags, location, this);
1465 if (PreviewFeatures.isEnabled() && reflectionFactory.classFileFormatVersion(this) != ClassFileFormatVersion.CURRENT_PREVIEW_FEATURES
1466 && isIdentity()) {
1467 var set = new HashSet<>(ans);
1468 set.add(AccessFlag.IDENTITY);
1469 return Set.copyOf(set);
1470 }
1471 return ans;
1472 }
1473
1474 /**
1475 * Gets the signers of this class.
1476 *
1477 * @return the signers of this class, or null if there are no signers. In
1478 * particular, this method returns null if this {@code Class} object represents
1479 * a primitive type or void.
1480 * @since 1.1
1481 */
1482
1483 public Object[] getSigners() {
1484 var signers = this.signers;
1485 return signers == null ? null : signers.clone();
1486 }
1487
1488 /**
1489 * Set the signers of this class.
1490 */
1491 void setSigners(Object[] signers) {
1492 if (!isPrimitive() && !isArray()) {
1493 this.signers = signers;
1494 }
1495 }
1496
1497 /**
1498 * If this {@code Class} object represents a local or anonymous
1499 * class within a method, returns a {@link
1500 * java.lang.reflect.Method Method} object representing the
1501 * immediately enclosing method of the underlying class. Returns
1502 * {@code null} otherwise.
1503 *
1504 * In particular, this method returns {@code null} if the underlying
1505 * class is a local or anonymous class immediately enclosed by a class or
1506 * interface declaration, instance initializer or static initializer.
1507 *
1508 * @return the immediately enclosing method of the underlying class, if
1509 * that class is a local or anonymous class; otherwise {@code null}.
1510 *
1511 * @since 1.5
1512 */
1513 public Method getEnclosingMethod() {
1514 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1515
1516 if (enclosingInfo == null)
1517 return null;
1518 else {
1519 if (!enclosingInfo.isMethod())
1520 return null;
1521
1522 // Descriptor already validated by VM
1523 List<Class<?>> types = BytecodeDescriptor.parseMethod(enclosingInfo.getDescriptor(), getClassLoader());
1524 Class<?> returnType = types.removeLast();
1525 Class<?>[] parameterClasses = types.toArray(EMPTY_CLASS_ARRAY);
1526
1527 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1528 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1529
1530 /*
1531 * Loop over all declared methods; match method name,
1532 * number of and type of parameters, *and* return
1533 * type. Matching return type is also necessary
1534 * because of covariant returns, etc.
1535 */
1536 ReflectionFactory fact = getReflectionFactory();
1537 for (Method m : candidates) {
1538 if (m.getName().equals(enclosingInfo.getName()) &&
1539 arrayContentsEq(parameterClasses,
1540 fact.getExecutableSharedParameterTypes(m))) {
1541 // finally, check return type
1542 if (m.getReturnType().equals(returnType)) {
1543 return fact.copyMethod(m);
1544 }
1545 }
1546 }
1547
1548 throw new InternalError("Enclosing method not found");
1549 }
1550 }
1551
1552 private native Object[] getEnclosingMethod0();
1553
1554 private EnclosingMethodInfo getEnclosingMethodInfo() {
1555 Object[] enclosingInfo = getEnclosingMethod0();
1556 if (enclosingInfo == null)
1557 return null;
1558 else {
1559 return new EnclosingMethodInfo(enclosingInfo);
1560 }
1561 }
1562
1563 private static final class EnclosingMethodInfo {
1564 private final Class<?> enclosingClass;
1565 private final String name;
1566 private final String descriptor;
1567
1568 static void validate(Object[] enclosingInfo) {
1569 if (enclosingInfo.length != 3)
1570 throw new InternalError("Malformed enclosing method information");
1571 try {
1572 // The array is expected to have three elements:
1573
1574 // the immediately enclosing class
1575 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1576 assert(enclosingClass != null);
1577
1578 // the immediately enclosing method or constructor's
1579 // name (can be null).
1580 String name = (String)enclosingInfo[1];
1581
1582 // the immediately enclosing method or constructor's
1583 // descriptor (null iff name is).
1584 String descriptor = (String)enclosingInfo[2];
1585 assert((name != null && descriptor != null) || name == descriptor);
1586 } catch (ClassCastException cce) {
1587 throw new InternalError("Invalid type in enclosing method information", cce);
1588 }
1589 }
1590
1591 EnclosingMethodInfo(Object[] enclosingInfo) {
1592 validate(enclosingInfo);
1593 this.enclosingClass = (Class<?>)enclosingInfo[0];
1594 this.name = (String)enclosingInfo[1];
1595 this.descriptor = (String)enclosingInfo[2];
1596 }
1597
1598 boolean isPartial() {
1599 return enclosingClass == null || name == null || descriptor == null;
1600 }
1601
1602 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1603
1604 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1605
1606 Class<?> getEnclosingClass() { return enclosingClass; }
1607
1608 String getName() { return name; }
1609
1610 String getDescriptor() { return descriptor; }
1611
1612 }
1613
1614 private static Class<?> toClass(Type o) {
1615 if (o instanceof GenericArrayType gat)
1616 return toClass(gat.getGenericComponentType()).arrayType();
1617 return (Class<?>)o;
1618 }
1619
1620 /**
1621 * If this {@code Class} object represents a local or anonymous
1622 * class within a constructor, returns a {@link
1623 * java.lang.reflect.Constructor Constructor} object representing
1624 * the immediately enclosing constructor of the underlying
1625 * class. Returns {@code null} otherwise. In particular, this
1626 * method returns {@code null} if the underlying class is a local
1627 * or anonymous class immediately enclosed by a class or
1628 * interface declaration, instance initializer or static initializer.
1629 *
1630 * @return the immediately enclosing constructor of the underlying class, if
1631 * that class is a local or anonymous class; otherwise {@code null}.
1632 *
1633 * @since 1.5
1634 */
1635 public Constructor<?> getEnclosingConstructor() {
1636 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1637
1638 if (enclosingInfo == null)
1639 return null;
1640 else {
1641 if (!enclosingInfo.isConstructor())
1642 return null;
1643
1644 // Descriptor already validated by VM
1645 List<Class<?>> types = BytecodeDescriptor.parseMethod(enclosingInfo.getDescriptor(), getClassLoader());
1646 types.removeLast();
1647 Class<?>[] parameterClasses = types.toArray(EMPTY_CLASS_ARRAY);
1648
1649 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1650 Constructor<?>[] candidates = enclosingCandidate
1651 .privateGetDeclaredConstructors(false);
1652 /*
1653 * Loop over all declared constructors; match number
1654 * of and type of parameters.
1655 */
1656 ReflectionFactory fact = getReflectionFactory();
1657 for (Constructor<?> c : candidates) {
1658 if (arrayContentsEq(parameterClasses,
1659 fact.getExecutableSharedParameterTypes(c))) {
1660 return fact.copyConstructor(c);
1661 }
1662 }
1663
1664 throw new InternalError("Enclosing constructor not found");
1665 }
1666 }
1667
1668
1669 /**
1670 * If the class or interface represented by this {@code Class} object
1671 * is a member of another class, returns the {@code Class} object
1672 * representing the class in which it was declared. This method returns
1673 * null if this class or interface is not a member of any other class. If
1674 * this {@code Class} object represents an array class, a primitive
1675 * type, or void, then this method returns null.
1676 *
1677 * @return the declaring class for this class
1678 * @since 1.1
1679 */
1680 public Class<?> getDeclaringClass() {
1681 return getDeclaringClass0();
1682 }
1683
1684 private native Class<?> getDeclaringClass0();
1685
1686
1687 /**
1688 * Returns the immediately enclosing class of the underlying
1689 * class. If the underlying class is a top level class this
1690 * method returns {@code null}.
1691 * @return the immediately enclosing class of the underlying class
1692 * @since 1.5
1693 */
1694 public Class<?> getEnclosingClass() {
1695 // There are five kinds of classes (or interfaces):
1696 // a) Top level classes
1697 // b) Nested classes (static member classes)
1698 // c) Inner classes (non-static member classes)
1699 // d) Local classes (named classes declared within a method)
1700 // e) Anonymous classes
1701
1702
1703 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1704 // attribute if and only if it is a local class or an
1705 // anonymous class.
1706 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1707 Class<?> enclosingCandidate;
1708
1709 if (enclosingInfo == null) {
1710 // This is a top level or a nested class or an inner class (a, b, or c)
1711 enclosingCandidate = getDeclaringClass0();
1712 } else {
1713 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1714 // This is a local class or an anonymous class (d or e)
1715 if (enclosingClass == this || enclosingClass == null)
1716 throw new InternalError("Malformed enclosing method information");
1717 else
1718 enclosingCandidate = enclosingClass;
1719 }
1720 return enclosingCandidate;
1721 }
1722
1723 /**
1724 * Returns the simple name of the underlying class as given in the
1725 * source code. An empty string is returned if the underlying class is
1726 * {@linkplain #isAnonymousClass() anonymous}.
1727 * A {@linkplain #isSynthetic() synthetic class}, one not present
1728 * in source code, can have a non-empty name including special
1729 * characters, such as "{@code $}".
1730 *
1731 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1732 * component type with "[]" appended. In particular the simple
1733 * name of an array class whose component type is anonymous is "[]".
1734 *
1735 * @return the simple name of the underlying class
1736 * @since 1.5
1737 */
1738 public String getSimpleName() {
1739 ReflectionData<T> rd = reflectionData();
1740 String simpleName = rd.simpleName;
1741 if (simpleName == null) {
1742 rd.simpleName = simpleName = getSimpleName0();
1743 }
1744 return simpleName;
1745 }
1746
1747 private String getSimpleName0() {
1748 if (isArray()) {
1749 return getComponentType().getSimpleName().concat("[]");
1750 }
1751 String simpleName = getSimpleBinaryName();
1752 if (simpleName == null) { // top level class
1753 simpleName = getName();
1754 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1755 }
1756 return simpleName;
1757 }
1758
1759 /**
1760 * Return an informative string for the name of this class or interface.
1761 *
1762 * @return an informative string for the name of this class or interface
1763 * @since 1.8
1764 */
1765 public String getTypeName() {
1766 if (isArray()) {
1767 try {
1768 Class<?> cl = this;
1769 int dimensions = 0;
1770 do {
1771 dimensions++;
1772 cl = cl.getComponentType();
1773 } while (cl.isArray());
1774 return cl.getName().concat("[]".repeat(dimensions));
1775 } catch (Throwable e) { /*FALLTHRU*/ }
1776 }
1777 return getName();
1778 }
1779
1780 /**
1781 * Returns the canonical name of the underlying class as
1782 * defined by <cite>The Java Language Specification</cite>.
1783 * Returns {@code null} if the underlying class does not have a canonical
1784 * name. Classes without canonical names include:
1785 * <ul>
1786 * <li>a {@linkplain #isLocalClass() local class}
1787 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1788 * <li>a {@linkplain #isHidden() hidden class}
1789 * <li>an array whose component type does not have a canonical name</li>
1790 * </ul>
1791 *
1792 * The canonical name for a primitive class is the keyword for the
1793 * corresponding primitive type ({@code byte}, {@code short},
1794 * {@code char}, {@code int}, and so on).
1795 *
1796 * <p>An array type has a canonical name if and only if its
1797 * component type has a canonical name. When an array type has a
1798 * canonical name, it is equal to the canonical name of the
1799 * component type followed by "{@code []}".
1800 *
1801 * @return the canonical name of the underlying class if it exists, and
1802 * {@code null} otherwise.
1803 * @jls 6.7 Fully Qualified Names and Canonical Names
1804 * @since 1.5
1805 */
1806 public String getCanonicalName() {
1807 ReflectionData<T> rd = reflectionData();
1808 String canonicalName = rd.canonicalName;
1809 if (canonicalName == null) {
1810 rd.canonicalName = canonicalName = getCanonicalName0();
1811 }
1812 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1813 }
1814
1815 private String getCanonicalName0() {
1816 if (isArray()) {
1817 String canonicalName = getComponentType().getCanonicalName();
1818 if (canonicalName != null)
1819 return canonicalName.concat("[]");
1820 else
1821 return ReflectionData.NULL_SENTINEL;
1822 }
1823 if (isHidden() || isLocalOrAnonymousClass())
1824 return ReflectionData.NULL_SENTINEL;
1825 Class<?> enclosingClass = getEnclosingClass();
1826 if (enclosingClass == null) { // top level class
1827 return getName();
1828 } else {
1829 String enclosingName = enclosingClass.getCanonicalName();
1830 if (enclosingName == null)
1831 return ReflectionData.NULL_SENTINEL;
1832 String simpleName = getSimpleName();
1833 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1834 .append(enclosingName)
1835 .append('.')
1836 .append(simpleName)
1837 .toString();
1838 }
1839 }
1840
1841 /**
1842 * Returns {@code true} if and only if the underlying class
1843 * is an anonymous class.
1844 *
1845 * @apiNote
1846 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1847 *
1848 * @return {@code true} if and only if this class is an anonymous class.
1849 * @since 1.5
1850 * @jls 15.9.5 Anonymous Class Declarations
1851 */
1852 public boolean isAnonymousClass() {
1853 return !isArray() && isLocalOrAnonymousClass() &&
1854 getSimpleBinaryName0() == null;
1855 }
1856
1857 /**
1858 * Returns {@code true} if and only if the underlying class
1859 * is a local class.
1860 *
1861 * @return {@code true} if and only if this class is a local class.
1862 * @since 1.5
1863 * @jls 14.3 Local Class and Interface Declarations
1864 */
1865 public boolean isLocalClass() {
1866 return isLocalOrAnonymousClass() &&
1867 (isArray() || getSimpleBinaryName0() != null);
1868 }
1869
1870 /**
1871 * Returns {@code true} if and only if the underlying class
1872 * is a member class.
1873 *
1874 * @return {@code true} if and only if this class is a member class.
1875 * @since 1.5
1876 * @jls 8.5 Member Class and Interface Declarations
1877 */
1878 public boolean isMemberClass() {
1879 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1880 }
1881
1882 /**
1883 * Returns the "simple binary name" of the underlying class, i.e.,
1884 * the binary name without the leading enclosing class name.
1885 * Returns {@code null} if the underlying class is a top level
1886 * class.
1887 */
1888 private String getSimpleBinaryName() {
1889 if (isTopLevelClass())
1890 return null;
1891 String name = getSimpleBinaryName0();
1892 if (name == null) // anonymous class
1893 return "";
1894 return name;
1895 }
1896
1897 private native String getSimpleBinaryName0();
1898
1899 /**
1900 * Returns {@code true} if this is a top level class. Returns {@code false}
1901 * otherwise.
1902 */
1903 private boolean isTopLevelClass() {
1904 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1905 }
1906
1907 /**
1908 * Returns {@code true} if this is a local class or an anonymous
1909 * class. Returns {@code false} otherwise.
1910 */
1911 private boolean isLocalOrAnonymousClass() {
1912 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1913 // attribute if and only if it is a local class or an
1914 // anonymous class.
1915 return hasEnclosingMethodInfo();
1916 }
1917
1918 private boolean hasEnclosingMethodInfo() {
1919 Object[] enclosingInfo = getEnclosingMethod0();
1920 if (enclosingInfo != null) {
1921 EnclosingMethodInfo.validate(enclosingInfo);
1922 return true;
1923 }
1924 return false;
1925 }
1926
1927 /**
1928 * Returns an array containing {@code Class} objects representing all
1929 * the public classes and interfaces that are members of the class
1930 * represented by this {@code Class} object. This includes public
1931 * class and interface members inherited from superclasses and public class
1932 * and interface members declared by the class. This method returns an
1933 * array of length 0 if this {@code Class} object has no public member
1934 * classes or interfaces. This method also returns an array of length 0 if
1935 * this {@code Class} object represents a primitive type, an array
1936 * class, or void.
1937 *
1938 * @return the array of {@code Class} objects representing the public
1939 * members of this class
1940 * @since 1.1
1941 */
1942 public Class<?>[] getClasses() {
1943 List<Class<?>> list = new ArrayList<>();
1944 Class<?> currentClass = Class.this;
1945 while (currentClass != null) {
1946 for (Class<?> m : currentClass.getDeclaredClasses()) {
1947 if (Modifier.isPublic(m.getModifiers())) {
1948 list.add(m);
1949 }
1950 }
1951 currentClass = currentClass.getSuperclass();
1952 }
1953 return list.toArray(EMPTY_CLASS_ARRAY);
1954 }
1955
1956
1957 /**
1958 * Returns an array containing {@code Field} objects reflecting all
1959 * the accessible public fields of the class or interface represented by
1960 * this {@code Class} object.
1961 *
1962 * <p> If this {@code Class} object represents a class or interface with
1963 * no accessible public fields, then this method returns an array of length
1964 * 0.
1965 *
1966 * <p> If this {@code Class} object represents a class, then this method
1967 * returns the public fields of the class and of all its superclasses and
1968 * superinterfaces.
1969 *
1970 * <p> If this {@code Class} object represents an interface, then this
1971 * method returns the fields of the interface and of all its
1972 * superinterfaces.
1973 *
1974 * <p> If this {@code Class} object represents an array type, a primitive
1975 * type, or void, then this method returns an array of length 0.
1976 *
1977 * <p> The elements in the returned array are not sorted and are not in any
1978 * particular order.
1979 *
1980 * @return the array of {@code Field} objects representing the
1981 * public fields
1982 *
1983 * @since 1.1
1984 * @jls 8.2 Class Members
1985 * @jls 8.3 Field Declarations
1986 */
1987 public Field[] getFields() {
1988 return copyFields(privateGetPublicFields());
1989 }
1990
1991
1992 /**
1993 * Returns an array containing {@code Method} objects reflecting all the
1994 * public methods of the class or interface represented by this {@code
1995 * Class} object, including those declared by the class or interface and
1996 * those inherited from superclasses and superinterfaces.
1997 *
1998 * <p> If this {@code Class} object represents an array type, then the
1999 * returned array has a {@code Method} object for each of the public
2000 * methods inherited by the array type from {@code Object}. It does not
2001 * contain a {@code Method} object for {@code clone()}.
2002 *
2003 * <p> If this {@code Class} object represents an interface then the
2004 * returned array does not contain any implicitly declared methods from
2005 * {@code Object}. Therefore, if no methods are explicitly declared in
2006 * this interface or any of its superinterfaces then the returned array
2007 * has length 0. (Note that a {@code Class} object which represents a class
2008 * always has public methods, inherited from {@code Object}.)
2009 *
2010 * <p> The returned array never contains methods with names {@value
2011 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2012 *
2013 * <p> The elements in the returned array are not sorted and are not in any
2014 * particular order.
2015 *
2016 * <p> Generally, the result is computed as with the following 4 step algorithm.
2017 * Let C be the class or interface represented by this {@code Class} object:
2018 * <ol>
2019 * <li> A union of methods is composed of:
2020 * <ol type="a">
2021 * <li> C's declared public instance and static methods as returned by
2022 * {@link #getDeclaredMethods()} and filtered to include only public
2023 * methods.</li>
2024 * <li> If C is a class other than {@code Object}, then include the result
2025 * of invoking this algorithm recursively on the superclass of C.</li>
2026 * <li> Include the results of invoking this algorithm recursively on all
2027 * direct superinterfaces of C, but include only instance methods.</li>
2028 * </ol></li>
2029 * <li> Union from step 1 is partitioned into subsets of methods with same
2030 * signature (name, parameter types) and return type.</li>
2031 * <li> Within each such subset only the most specific methods are selected.
2032 * Let method M be a method from a set of methods with same signature
2033 * and return type. M is most specific if there is no such method
2034 * N != M from the same set, such that N is more specific than M.
2035 * N is more specific than M if:
2036 * <ol type="a">
2037 * <li> N is declared by a class and M is declared by an interface; or</li>
2038 * <li> N and M are both declared by classes or both by interfaces and
2039 * N's declaring type is the same as or a subtype of M's declaring type
2040 * (clearly, if M's and N's declaring types are the same type, then
2041 * M and N are the same method).</li>
2042 * </ol></li>
2043 * <li> The result of this algorithm is the union of all selected methods from
2044 * step 3.</li>
2045 * </ol>
2046 *
2047 * @apiNote There may be more than one method with a particular name
2048 * and parameter types in a class because while the Java language forbids a
2049 * class to declare multiple methods with the same signature but different
2050 * return types, the Java virtual machine does not. This
2051 * increased flexibility in the virtual machine can be used to
2052 * implement various language features. For example, covariant
2053 * returns can be implemented with {@linkplain
2054 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2055 * method and the overriding method would have the same
2056 * signature but different return types.
2057 *
2058 * @return the array of {@code Method} objects representing the
2059 * public methods of this class
2060 *
2061 * @jls 8.2 Class Members
2062 * @jls 8.4 Method Declarations
2063 * @since 1.1
2064 */
2065 public Method[] getMethods() {
2066 return copyMethods(privateGetPublicMethods());
2067 }
2068
2069
2070 /**
2071 * Returns an array containing {@code Constructor} objects reflecting
2072 * all the public constructors of the class represented by this
2073 * {@code Class} object. An array of length 0 is returned if the
2074 * class has no public constructors, or if the class is an array class, or
2075 * if the class reflects a primitive type or void.
2076 *
2077 * @apiNote
2078 * While this method returns an array of {@code
2079 * Constructor<T>} objects (that is an array of constructors from
2080 * this class), the return type of this method is {@code
2081 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2082 * might be expected. This less informative return type is
2083 * necessary since after being returned from this method, the
2084 * array could be modified to hold {@code Constructor} objects for
2085 * different classes, which would violate the type guarantees of
2086 * {@code Constructor<T>[]}.
2087 *
2088 * @return the array of {@code Constructor} objects representing the
2089 * public constructors of this class
2090 *
2091 * @see #getDeclaredConstructors()
2092 * @since 1.1
2093 */
2094 public Constructor<?>[] getConstructors() {
2095 return copyConstructors(privateGetDeclaredConstructors(true));
2096 }
2097
2098
2099 /**
2100 * Returns a {@code Field} object that reflects the specified public member
2101 * field of the class or interface represented by this {@code Class}
2102 * object. The {@code name} parameter is a {@code String} specifying the
2103 * simple name of the desired field.
2104 *
2105 * <p> The field to be reflected is determined by the algorithm that
2106 * follows. Let C be the class or interface represented by this {@code Class} object:
2107 *
2108 * <OL>
2109 * <LI> If C declares a public field with the name specified, that is the
2110 * field to be reflected.</LI>
2111 * <LI> If no field was found in step 1 above, this algorithm is applied
2112 * recursively to each direct superinterface of C. The direct
2113 * superinterfaces are searched in the order they were declared.</LI>
2114 * <LI> If no field was found in steps 1 and 2 above, and C has a
2115 * superclass S, then this algorithm is invoked recursively upon S.
2116 * If C has no superclass, then a {@code NoSuchFieldException}
2117 * is thrown.</LI>
2118 * </OL>
2119 *
2120 * <p> If this {@code Class} object represents an array type, then this
2121 * method does not find the {@code length} field of the array type.
2122 *
2123 * @param name the field name
2124 * @return the {@code Field} object of this class specified by
2125 * {@code name}
2126 * @throws NoSuchFieldException if a field with the specified name is
2127 * not found.
2128 * @throws NullPointerException if {@code name} is {@code null}
2129 *
2130 * @since 1.1
2131 * @jls 8.2 Class Members
2132 * @jls 8.3 Field Declarations
2133 */
2134 public Field getField(String name) throws NoSuchFieldException {
2135 Objects.requireNonNull(name);
2136 Field field = getField0(name);
2137 if (field == null) {
2138 throw new NoSuchFieldException(name);
2139 }
2140 return getReflectionFactory().copyField(field);
2141 }
2142
2143
2144 /**
2145 * Returns a {@code Method} object that reflects the specified public
2146 * member method of the class or interface represented by this
2147 * {@code Class} object. The {@code name} parameter is a
2148 * {@code String} specifying the simple name of the desired method. The
2149 * {@code parameterTypes} parameter is an array of {@code Class}
2150 * objects that identify the method's formal parameter types, in declared
2151 * order. If {@code parameterTypes} is {@code null}, it is
2152 * treated as if it were an empty array.
2153 *
2154 * <p> If this {@code Class} object represents an array type, then this
2155 * method finds any public method inherited by the array type from
2156 * {@code Object} except method {@code clone()}.
2157 *
2158 * <p> If this {@code Class} object represents an interface then this
2159 * method does not find any implicitly declared method from
2160 * {@code Object}. Therefore, if no methods are explicitly declared in
2161 * this interface or any of its superinterfaces, then this method does not
2162 * find any method.
2163 *
2164 * <p> This method does not find any method with name {@value
2165 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2166 *
2167 * <p> Generally, the method to be reflected is determined by the 4 step
2168 * algorithm that follows.
2169 * Let C be the class or interface represented by this {@code Class} object:
2170 * <ol>
2171 * <li> A union of methods is composed of:
2172 * <ol type="a">
2173 * <li> C's declared public instance and static methods as returned by
2174 * {@link #getDeclaredMethods()} and filtered to include only public
2175 * methods that match given {@code name} and {@code parameterTypes}</li>
2176 * <li> If C is a class other than {@code Object}, then include the result
2177 * of invoking this algorithm recursively on the superclass of C.</li>
2178 * <li> Include the results of invoking this algorithm recursively on all
2179 * direct superinterfaces of C, but include only instance methods.</li>
2180 * </ol></li>
2181 * <li> This union is partitioned into subsets of methods with same
2182 * return type (the selection of methods from step 1 also guarantees that
2183 * they have the same method name and parameter types).</li>
2184 * <li> Within each such subset only the most specific methods are selected.
2185 * Let method M be a method from a set of methods with same VM
2186 * signature (return type, name, parameter types).
2187 * M is most specific if there is no such method N != M from the same
2188 * set, such that N is more specific than M. N is more specific than M
2189 * if:
2190 * <ol type="a">
2191 * <li> N is declared by a class and M is declared by an interface; or</li>
2192 * <li> N and M are both declared by classes or both by interfaces and
2193 * N's declaring type is the same as or a subtype of M's declaring type
2194 * (clearly, if M's and N's declaring types are the same type, then
2195 * M and N are the same method).</li>
2196 * </ol></li>
2197 * <li> The result of this algorithm is chosen arbitrarily from the methods
2198 * with most specific return type among all selected methods from step 3.
2199 * Let R be a return type of a method M from the set of all selected methods
2200 * from step 3. M is a method with most specific return type if there is
2201 * no such method N != M from the same set, having return type S != R,
2202 * such that S is a subtype of R as determined by
2203 * R.class.{@link #isAssignableFrom}(S.class).
2204 * </ol>
2205 *
2206 * @apiNote There may be more than one method with matching name and
2207 * parameter types in a class because while the Java language forbids a
2208 * class to declare multiple methods with the same signature but different
2209 * return types, the Java virtual machine does not. This
2210 * increased flexibility in the virtual machine can be used to
2211 * implement various language features. For example, covariant
2212 * returns can be implemented with {@linkplain
2213 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2214 * method and the overriding method would have the same
2215 * signature but different return types. This method would return the
2216 * overriding method as it would have a more specific return type.
2217 *
2218 * @param name the name of the method
2219 * @param parameterTypes the list of parameters
2220 * @return the {@code Method} object that matches the specified
2221 * {@code name} and {@code parameterTypes}
2222 * @throws NoSuchMethodException if a matching method is not found
2223 * or if the name is {@value ConstantDescs#INIT_NAME} or
2224 * {@value ConstantDescs#CLASS_INIT_NAME}.
2225 * @throws NullPointerException if {@code name} is {@code null}
2226 *
2227 * @jls 8.2 Class Members
2228 * @jls 8.4 Method Declarations
2229 * @since 1.1
2230 */
2231 public Method getMethod(String name, Class<?>... parameterTypes)
2232 throws NoSuchMethodException {
2233 Objects.requireNonNull(name);
2234 Method method = getMethod0(name, parameterTypes);
2235 if (method == null) {
2236 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2237 }
2238 return getReflectionFactory().copyMethod(method);
2239 }
2240
2241 /**
2242 * Returns a {@code Constructor} object that reflects the specified
2243 * public constructor of the class represented by this {@code Class}
2244 * object. The {@code parameterTypes} parameter is an array of
2245 * {@code Class} objects that identify the constructor's formal
2246 * parameter types, in declared order.
2247 *
2248 * If this {@code Class} object represents an inner class
2249 * declared in a non-static context, the formal parameter types
2250 * include the explicit enclosing instance as the first parameter.
2251 *
2252 * <p> The constructor to reflect is the public constructor of the class
2253 * represented by this {@code Class} object whose formal parameter
2254 * types match those specified by {@code parameterTypes}.
2255 *
2256 * @param parameterTypes the parameter array
2257 * @return the {@code Constructor} object of the public constructor that
2258 * matches the specified {@code parameterTypes}
2259 * @throws NoSuchMethodException if a matching constructor is not found,
2260 * including when this {@code Class} object represents
2261 * an interface, a primitive type, an array class, or void.
2262 *
2263 * @see #getDeclaredConstructor(Class[])
2264 * @since 1.1
2265 */
2266 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2267 throws NoSuchMethodException {
2268 return getReflectionFactory().copyConstructor(
2269 getConstructor0(parameterTypes, Member.PUBLIC));
2270 }
2271
2272
2273 /**
2274 * Returns an array of {@code Class} objects reflecting all the
2275 * classes and interfaces declared as members of the class represented by
2276 * this {@code Class} object. This includes public, protected, default
2277 * (package) access, and private classes and interfaces declared by the
2278 * class, but excludes inherited classes and interfaces. This method
2279 * returns an array of length 0 if the class declares no classes or
2280 * interfaces as members, or if this {@code Class} object represents a
2281 * primitive type, an array class, or void.
2282 *
2283 * @return the array of {@code Class} objects representing all the
2284 * declared members of this class
2285 *
2286 * @since 1.1
2287 * @jls 8.5 Member Class and Interface Declarations
2288 */
2289 public Class<?>[] getDeclaredClasses() {
2290 return getDeclaredClasses0();
2291 }
2292
2293
2294 /**
2295 * Returns an array of {@code Field} objects reflecting all the fields
2296 * declared by the class or interface represented by this
2297 * {@code Class} object. This includes public, protected, default
2298 * (package) access, and private fields, but excludes inherited fields.
2299 *
2300 * <p> If this {@code Class} object represents a class or interface with no
2301 * declared fields, then this method returns an array of length 0.
2302 *
2303 * <p> If this {@code Class} object represents an array type, a primitive
2304 * type, or void, then this method returns an array of length 0.
2305 *
2306 * <p> The elements in the returned array are not sorted and are not in any
2307 * particular order.
2308 *
2309 * @return the array of {@code Field} objects representing all the
2310 * declared fields of this class
2311 *
2312 * @since 1.1
2313 * @jls 8.2 Class Members
2314 * @jls 8.3 Field Declarations
2315 */
2316 public Field[] getDeclaredFields() {
2317 return copyFields(privateGetDeclaredFields(false));
2318 }
2319
2320 /**
2321 * Returns an array of {@code RecordComponent} objects representing all the
2322 * record components of this record class, or {@code null} if this class is
2323 * not a record class.
2324 *
2325 * <p> The components are returned in the same order that they are declared
2326 * in the record header. The array is empty if this record class has no
2327 * components. If the class is not a record class, that is {@link
2328 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2329 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2330 * returns a non-null value.
2331 *
2332 * @apiNote
2333 * <p> The following method can be used to find the record canonical constructor:
2334 *
2335 * {@snippet lang="java" :
2336 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2337 * throws NoSuchMethodException {
2338 * Class<?>[] paramTypes =
2339 * Arrays.stream(cls.getRecordComponents())
2340 * .map(RecordComponent::getType)
2341 * .toArray(Class<?>[]::new);
2342 * return cls.getDeclaredConstructor(paramTypes);
2343 * }}
2344 *
2345 * @return An array of {@code RecordComponent} objects representing all the
2346 * record components of this record class, or {@code null} if this
2347 * class is not a record class
2348 *
2349 * @jls 8.10 Record Classes
2350 * @since 16
2351 */
2352 public RecordComponent[] getRecordComponents() {
2353 if (!isRecord()) {
2354 return null;
2355 }
2356 return getRecordComponents0();
2357 }
2358
2359 /**
2360 * Returns an array containing {@code Method} objects reflecting all the
2361 * declared methods of the class or interface represented by this {@code
2362 * Class} object, including public, protected, default (package)
2363 * access, and private methods, but excluding inherited methods.
2364 * The declared methods may include methods <em>not</em> in the
2365 * source of the class or interface, including {@linkplain
2366 * Method#isBridge bridge methods} and other {@linkplain
2367 * Executable#isSynthetic synthetic} methods added by compilers.
2368 *
2369 * <p> If this {@code Class} object represents a class or interface that
2370 * has multiple declared methods with the same name and parameter types,
2371 * but different return types, then the returned array has a {@code Method}
2372 * object for each such method.
2373 *
2374 * <p> If this {@code Class} object represents a class or interface that
2375 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2376 * then the returned array does <em>not</em> have a corresponding {@code
2377 * Method} object.
2378 *
2379 * <p> If this {@code Class} object represents a class or interface with no
2380 * declared methods, then the returned array has length 0.
2381 *
2382 * <p> If this {@code Class} object represents an array type, a primitive
2383 * type, or void, then the returned array has length 0.
2384 *
2385 * <p> The elements in the returned array are not sorted and are not in any
2386 * particular order.
2387 *
2388 * @return the array of {@code Method} objects representing all the
2389 * declared methods of this class
2390 *
2391 * @jls 8.2 Class Members
2392 * @jls 8.4 Method Declarations
2393 * @see <a
2394 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2395 * programming language and JVM modeling in core reflection</a>
2396 * @since 1.1
2397 */
2398 public Method[] getDeclaredMethods() {
2399 return copyMethods(privateGetDeclaredMethods(false));
2400 }
2401
2402 /**
2403 * Returns an array of {@code Constructor} objects reflecting all the
2404 * constructors implicitly or explicitly declared by the class represented by this
2405 * {@code Class} object. These are public, protected, default
2406 * (package) access, and private constructors. The elements in the array
2407 * returned are not sorted and are not in any particular order. If the
2408 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2409 * If a record class has a canonical constructor (JLS {@jls
2410 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2411 *
2412 * This method returns an array of length 0 if this {@code Class}
2413 * object represents an interface, a primitive type, an array class, or
2414 * void.
2415 *
2416 * @return the array of {@code Constructor} objects representing all the
2417 * declared constructors of this class
2418 *
2419 * @since 1.1
2420 * @see #getConstructors()
2421 * @jls 8.8 Constructor Declarations
2422 */
2423 public Constructor<?>[] getDeclaredConstructors() {
2424 return copyConstructors(privateGetDeclaredConstructors(false));
2425 }
2426
2427
2428 /**
2429 * Returns a {@code Field} object that reflects the specified declared
2430 * field of the class or interface represented by this {@code Class}
2431 * object. The {@code name} parameter is a {@code String} that specifies
2432 * the simple name of the desired field.
2433 *
2434 * <p> If this {@code Class} object represents an array type, then this
2435 * method does not find the {@code length} field of the array type.
2436 *
2437 * @param name the name of the field
2438 * @return the {@code Field} object for the specified field in this
2439 * class
2440 * @throws NoSuchFieldException if a field with the specified name is
2441 * not found.
2442 * @throws NullPointerException if {@code name} is {@code null}
2443 *
2444 * @since 1.1
2445 * @jls 8.2 Class Members
2446 * @jls 8.3 Field Declarations
2447 */
2448 public Field getDeclaredField(String name) throws NoSuchFieldException {
2449 Objects.requireNonNull(name);
2450 Field field = searchFields(privateGetDeclaredFields(false), name);
2451 if (field == null) {
2452 throw new NoSuchFieldException(name);
2453 }
2454 return getReflectionFactory().copyField(field);
2455 }
2456
2457
2458 /**
2459 * Returns a {@code Method} object that reflects the specified
2460 * declared method of the class or interface represented by this
2461 * {@code Class} object. The {@code name} parameter is a
2462 * {@code String} that specifies the simple name of the desired
2463 * method, and the {@code parameterTypes} parameter is an array of
2464 * {@code Class} objects that identify the method's formal parameter
2465 * types, in declared order. If more than one method with the same
2466 * parameter types is declared in a class, and one of these methods has a
2467 * return type that is more specific than any of the others, that method is
2468 * returned; otherwise one of the methods is chosen arbitrarily. If the
2469 * name is {@value ConstantDescs#INIT_NAME} or {@value
2470 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2471 * is raised.
2472 *
2473 * <p> If this {@code Class} object represents an array type, then this
2474 * method does not find the {@code clone()} method.
2475 *
2476 * @param name the name of the method
2477 * @param parameterTypes the parameter array
2478 * @return the {@code Method} object for the method of this class
2479 * matching the specified name and parameters
2480 * @throws NoSuchMethodException if a matching method is not found.
2481 * @throws NullPointerException if {@code name} is {@code null}
2482 *
2483 * @jls 8.2 Class Members
2484 * @jls 8.4 Method Declarations
2485 * @since 1.1
2486 */
2487 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2488 throws NoSuchMethodException {
2489 Objects.requireNonNull(name);
2490 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2491 if (method == null) {
2492 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2493 }
2494 return getReflectionFactory().copyMethod(method);
2495 }
2496
2497 /**
2498 * Returns the list of {@code Method} objects for the declared public
2499 * methods of this class or interface that have the specified method name
2500 * and parameter types.
2501 *
2502 * @param name the name of the method
2503 * @param parameterTypes the parameter array
2504 * @return the list of {@code Method} objects for the public methods of
2505 * this class matching the specified name and parameters
2506 */
2507 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2508 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2509 ReflectionFactory factory = getReflectionFactory();
2510 List<Method> result = new ArrayList<>();
2511 for (Method method : methods) {
2512 if (method.getName().equals(name)
2513 && Arrays.equals(
2514 factory.getExecutableSharedParameterTypes(method),
2515 parameterTypes)) {
2516 result.add(factory.copyMethod(method));
2517 }
2518 }
2519 return result;
2520 }
2521
2522 /**
2523 * Returns the most specific {@code Method} object of this class, super class or
2524 * interface that have the specified method name and parameter types.
2525 *
2526 * @param publicOnly true if only public methods are examined, otherwise all methods
2527 * @param name the name of the method
2528 * @param parameterTypes the parameter array
2529 * @return the {@code Method} object for the method found from this class matching
2530 * the specified name and parameters, or null if not found
2531 */
2532 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2533 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2534 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2535 }
2536
2537 /**
2538 * Returns a {@code Constructor} object that reflects the specified
2539 * constructor of the class represented by this
2540 * {@code Class} object. The {@code parameterTypes} parameter is
2541 * an array of {@code Class} objects that identify the constructor's
2542 * formal parameter types, in declared order.
2543 *
2544 * If this {@code Class} object represents an inner class
2545 * declared in a non-static context, the formal parameter types
2546 * include the explicit enclosing instance as the first parameter.
2547 *
2548 * @param parameterTypes the parameter array
2549 * @return The {@code Constructor} object for the constructor with the
2550 * specified parameter list
2551 * @throws NoSuchMethodException if a matching constructor is not found,
2552 * including when this {@code Class} object represents
2553 * an interface, a primitive type, an array class, or void.
2554 *
2555 * @see #getConstructor(Class[])
2556 * @since 1.1
2557 */
2558 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2559 throws NoSuchMethodException {
2560 return getReflectionFactory().copyConstructor(
2561 getConstructor0(parameterTypes, Member.DECLARED));
2562 }
2563
2564 /**
2565 * Finds a resource with a given name.
2566 *
2567 * <p> If this class is in a named {@link Module Module} then this method
2568 * will attempt to find the resource in the module. This is done by
2569 * delegating to the module's class loader {@link
2570 * ClassLoader#findResource(String,String) findResource(String,String)}
2571 * method, invoking it with the module name and the absolute name of the
2572 * resource. Resources in named modules are subject to the rules for
2573 * encapsulation specified in the {@code Module} {@link
2574 * Module#getResourceAsStream getResourceAsStream} method and so this
2575 * method returns {@code null} when the resource is a
2576 * non-"{@code .class}" resource in a package that is not open to the
2577 * caller's module.
2578 *
2579 * <p> Otherwise, if this class is not in a named module then the rules for
2580 * searching resources associated with a given class are implemented by the
2581 * defining {@linkplain ClassLoader class loader} of the class. This method
2582 * delegates to this {@code Class} object's class loader.
2583 * If this {@code Class} object was loaded by the bootstrap class loader,
2584 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2585 *
2586 * <p> Before delegation, an absolute resource name is constructed from the
2587 * given resource name using this algorithm:
2588 *
2589 * <ul>
2590 *
2591 * <li> If the {@code name} begins with a {@code '/'}
2592 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2593 * portion of the {@code name} following the {@code '/'}.
2594 *
2595 * <li> Otherwise, the absolute name is of the following form:
2596 *
2597 * <blockquote>
2598 * {@code modified_package_name/name}
2599 * </blockquote>
2600 *
2601 * <p> Where the {@code modified_package_name} is the package name of this
2602 * object with {@code '/'} substituted for {@code '.'}
2603 * (<code>'\u002e'</code>).
2604 *
2605 * </ul>
2606 *
2607 * @param name name of the desired resource
2608 * @return A {@link java.io.InputStream} object; {@code null} if no
2609 * resource with this name is found, or the resource is in a package
2610 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2611 * least the caller module.
2612 * @throws NullPointerException If {@code name} is {@code null}
2613 *
2614 * @see Module#getResourceAsStream(String)
2615 * @since 1.1
2616 */
2617 @CallerSensitive
2618 public InputStream getResourceAsStream(String name) {
2619 name = resolveName(name);
2620
2621 Module thisModule = getModule();
2622 if (thisModule.isNamed()) {
2623 // check if resource can be located by caller
2624 if (Resources.canEncapsulate(name)
2625 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2626 return null;
2627 }
2628
2629 // resource not encapsulated or in package open to caller
2630 String mn = thisModule.getName();
2631 ClassLoader cl = classLoader;
2632 try {
2633
2634 // special-case built-in class loaders to avoid the
2635 // need for a URL connection
2636 if (cl == null) {
2637 return BootLoader.findResourceAsStream(mn, name);
2638 } else if (cl instanceof BuiltinClassLoader bcl) {
2639 return bcl.findResourceAsStream(mn, name);
2640 } else {
2641 URL url = cl.findResource(mn, name);
2642 return (url != null) ? url.openStream() : null;
2643 }
2644
2645 } catch (IOException | SecurityException e) {
2646 return null;
2647 }
2648 }
2649
2650 // unnamed module
2651 ClassLoader cl = classLoader;
2652 if (cl == null) {
2653 return ClassLoader.getSystemResourceAsStream(name);
2654 } else {
2655 return cl.getResourceAsStream(name);
2656 }
2657 }
2658
2659 /**
2660 * Finds a resource with a given name.
2661 *
2662 * <p> If this class is in a named {@link Module Module} then this method
2663 * will attempt to find the resource in the module. This is done by
2664 * delegating to the module's class loader {@link
2665 * ClassLoader#findResource(String,String) findResource(String,String)}
2666 * method, invoking it with the module name and the absolute name of the
2667 * resource. Resources in named modules are subject to the rules for
2668 * encapsulation specified in the {@code Module} {@link
2669 * Module#getResourceAsStream getResourceAsStream} method and so this
2670 * method returns {@code null} when the resource is a
2671 * non-"{@code .class}" resource in a package that is not open to the
2672 * caller's module.
2673 *
2674 * <p> Otherwise, if this class is not in a named module then the rules for
2675 * searching resources associated with a given class are implemented by the
2676 * defining {@linkplain ClassLoader class loader} of the class. This method
2677 * delegates to this {@code Class} object's class loader.
2678 * If this {@code Class} object was loaded by the bootstrap class loader,
2679 * the method delegates to {@link ClassLoader#getSystemResource}.
2680 *
2681 * <p> Before delegation, an absolute resource name is constructed from the
2682 * given resource name using this algorithm:
2683 *
2684 * <ul>
2685 *
2686 * <li> If the {@code name} begins with a {@code '/'}
2687 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2688 * portion of the {@code name} following the {@code '/'}.
2689 *
2690 * <li> Otherwise, the absolute name is of the following form:
2691 *
2692 * <blockquote>
2693 * {@code modified_package_name/name}
2694 * </blockquote>
2695 *
2696 * <p> Where the {@code modified_package_name} is the package name of this
2697 * object with {@code '/'} substituted for {@code '.'}
2698 * (<code>'\u002e'</code>).
2699 *
2700 * </ul>
2701 *
2702 * @param name name of the desired resource
2703 * @return A {@link java.net.URL} object; {@code null} if no resource with
2704 * this name is found, the resource cannot be located by a URL, or the
2705 * resource is in a package that is not
2706 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2707 * module.
2708 * @throws NullPointerException If {@code name} is {@code null}
2709 * @since 1.1
2710 */
2711 @CallerSensitive
2712 public URL getResource(String name) {
2713 name = resolveName(name);
2714
2715 Module thisModule = getModule();
2716 if (thisModule.isNamed()) {
2717 // check if resource can be located by caller
2718 if (Resources.canEncapsulate(name)
2719 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2720 return null;
2721 }
2722
2723 // resource not encapsulated or in package open to caller
2724 String mn = thisModule.getName();
2725 ClassLoader cl = classLoader;
2726 try {
2727 if (cl == null) {
2728 return BootLoader.findResource(mn, name);
2729 } else {
2730 return cl.findResource(mn, name);
2731 }
2732 } catch (IOException ioe) {
2733 return null;
2734 }
2735 }
2736
2737 // unnamed module
2738 ClassLoader cl = classLoader;
2739 if (cl == null) {
2740 return ClassLoader.getSystemResource(name);
2741 } else {
2742 return cl.getResource(name);
2743 }
2744 }
2745
2746 /**
2747 * Returns true if a resource with the given name can be located by the
2748 * given caller. All resources in a module can be located by code in
2749 * the module. For other callers, then the package needs to be open to
2750 * the caller.
2751 */
2752 private boolean isOpenToCaller(String name, Class<?> caller) {
2753 // assert getModule().isNamed();
2754 Module thisModule = getModule();
2755 Module callerModule = (caller != null) ? caller.getModule() : null;
2756 if (callerModule != thisModule) {
2757 String pn = Resources.toPackageName(name);
2758 if (thisModule.getDescriptor().packages().contains(pn)) {
2759 if (callerModule == null) {
2760 // no caller, return true if the package is open to all modules
2761 return thisModule.isOpen(pn);
2762 }
2763 if (!thisModule.isOpen(pn, callerModule)) {
2764 // package not open to caller
2765 return false;
2766 }
2767 }
2768 }
2769 return true;
2770 }
2771
2772 private transient final ProtectionDomain protectionDomain;
2773
2774 /** Holder for the protection domain returned when the internal domain is null */
2775 private static class Holder {
2776 private static final ProtectionDomain allPermDomain;
2777 static {
2778 Permissions perms = new Permissions();
2779 perms.add(new AllPermission());
2780 allPermDomain = new ProtectionDomain(null, perms);
2781 }
2782 }
2783
2784 /**
2785 * Returns the {@code ProtectionDomain} of this class.
2786 *
2787 * @return the ProtectionDomain of this class
2788 *
2789 * @see java.security.ProtectionDomain
2790 * @since 1.2
2791 */
2792 public ProtectionDomain getProtectionDomain() {
2793 if (protectionDomain == null) {
2794 return Holder.allPermDomain;
2795 } else {
2796 return protectionDomain;
2797 }
2798 }
2799
2800 /*
2801 * Returns the Class object for the named primitive type. Type parameter T
2802 * avoids redundant casts for trusted code.
2803 */
2804 static native <T> Class<T> getPrimitiveClass(String name);
2805
2806 /**
2807 * Add a package name prefix if the name is not absolute. Remove leading "/"
2808 * if name is absolute
2809 */
2810 private String resolveName(String name) {
2811 if (!name.startsWith("/")) {
2812 String baseName = getPackageName();
2813 if (!baseName.isEmpty()) {
2814 int len = baseName.length() + 1 + name.length();
2815 StringBuilder sb = new StringBuilder(len);
2816 name = sb.append(baseName.replace('.', '/'))
2817 .append('/')
2818 .append(name)
2819 .toString();
2820 }
2821 } else {
2822 name = name.substring(1);
2823 }
2824 return name;
2825 }
2826
2827 /**
2828 * Atomic operations support.
2829 */
2830 private static class Atomic {
2831 // initialize Unsafe machinery here, since we need to call Class.class instance method
2832 // and have to avoid calling it in the static initializer of the Class class...
2833 private static final Unsafe unsafe = Unsafe.getUnsafe();
2834 // offset of Class.reflectionData instance field
2835 private static final long reflectionDataOffset
2836 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2837 // offset of Class.annotationType instance field
2838 private static final long annotationTypeOffset
2839 = unsafe.objectFieldOffset(Class.class, "annotationType");
2840 // offset of Class.annotationData instance field
2841 private static final long annotationDataOffset
2842 = unsafe.objectFieldOffset(Class.class, "annotationData");
2843
2844 static <T> boolean casReflectionData(Class<?> clazz,
2845 SoftReference<ReflectionData<T>> oldData,
2846 SoftReference<ReflectionData<T>> newData) {
2847 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2848 }
2849
2850 static boolean casAnnotationType(Class<?> clazz,
2851 AnnotationType oldType,
2852 AnnotationType newType) {
2853 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2854 }
2855
2856 static boolean casAnnotationData(Class<?> clazz,
2857 AnnotationData oldData,
2858 AnnotationData newData) {
2859 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2860 }
2861 }
2862
2863 /**
2864 * Reflection support.
2865 */
2866
2867 // Reflection data caches various derived names and reflective members. Cached
2868 // values may be invalidated when JVM TI RedefineClasses() is called
2869 private static class ReflectionData<T> {
2870 volatile Field[] declaredFields;
2871 volatile Field[] publicFields;
2872 volatile Method[] declaredMethods;
2873 volatile Method[] publicMethods;
2874 volatile Constructor<T>[] declaredConstructors;
2875 volatile Constructor<T>[] publicConstructors;
2876 // Intermediate results for getFields and getMethods
2877 volatile Field[] declaredPublicFields;
2878 volatile Method[] declaredPublicMethods;
2879 volatile Class<?>[] interfaces;
2880
2881 // Cached names
2882 String simpleName;
2883 String canonicalName;
2884 static final String NULL_SENTINEL = new String();
2885
2886 // Value of classRedefinedCount when we created this ReflectionData instance
2887 final int redefinedCount;
2888
2889 ReflectionData(int redefinedCount) {
2890 this.redefinedCount = redefinedCount;
2891 }
2892 }
2893
2894 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2895
2896 // Incremented by the VM on each call to JVM TI RedefineClasses()
2897 // that redefines this class or a superclass.
2898 private transient volatile int classRedefinedCount;
2899
2900 // Lazily create and cache ReflectionData
2901 private ReflectionData<T> reflectionData() {
2902 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2903 int classRedefinedCount = this.classRedefinedCount;
2904 ReflectionData<T> rd;
2905 if (reflectionData != null &&
2906 (rd = reflectionData.get()) != null &&
2907 rd.redefinedCount == classRedefinedCount) {
2908 return rd;
2909 }
2910 // else no SoftReference or cleared SoftReference or stale ReflectionData
2911 // -> create and replace new instance
2912 return newReflectionData(reflectionData, classRedefinedCount);
2913 }
2914
2915 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2916 int classRedefinedCount) {
2917 while (true) {
2918 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2919 // try to CAS it...
2920 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
2921 return rd;
2922 }
2923 // else retry
2924 oldReflectionData = this.reflectionData;
2925 classRedefinedCount = this.classRedefinedCount;
2926 if (oldReflectionData != null &&
2927 (rd = oldReflectionData.get()) != null &&
2928 rd.redefinedCount == classRedefinedCount) {
2929 return rd;
2930 }
2931 }
2932 }
2933
2934 // Generic signature handling
2935 private native String getGenericSignature0();
2936
2937 // Generic info repository; lazily initialized
2938 private transient volatile ClassRepository genericInfo;
2939
2940 // accessor for factory
2941 private GenericsFactory getFactory() {
2942 // create scope and factory
2943 return CoreReflectionFactory.make(this, ClassScope.make(this));
2944 }
2945
2946 // accessor for generic info repository;
2947 // generic info is lazily initialized
2948 private ClassRepository getGenericInfo() {
2949 ClassRepository genericInfo = this.genericInfo;
2950 if (genericInfo == null) {
2951 String signature = getGenericSignature0();
2952 if (signature == null) {
2953 genericInfo = ClassRepository.NONE;
2954 } else {
2955 genericInfo = ClassRepository.make(signature, getFactory());
2956 }
2957 this.genericInfo = genericInfo;
2958 }
2959 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2960 }
2961
2962 // Annotations handling
2963 native byte[] getRawAnnotations();
2964 // Since 1.8
2965 native byte[] getRawTypeAnnotations();
2966 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2967 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2968 }
2969
2970 native ConstantPool getConstantPool();
2971
2972 //
2973 //
2974 // java.lang.reflect.Field handling
2975 //
2976 //
2977
2978 // Returns an array of "root" fields. These Field objects must NOT
2979 // be propagated to the outside world, but must instead be copied
2980 // via ReflectionFactory.copyField.
2981 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2982 Field[] res;
2983 ReflectionData<T> rd = reflectionData();
2984 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2985 if (res != null) return res;
2986 // No cached value available; request value from VM
2987 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2988 if (publicOnly) {
2989 rd.declaredPublicFields = res;
2990 } else {
2991 rd.declaredFields = res;
2992 }
2993 return res;
2994 }
2995
2996 // Returns an array of "root" fields. These Field objects must NOT
2997 // be propagated to the outside world, but must instead be copied
2998 // via ReflectionFactory.copyField.
2999 private Field[] privateGetPublicFields() {
3000 Field[] res;
3001 ReflectionData<T> rd = reflectionData();
3002 res = rd.publicFields;
3003 if (res != null) return res;
3004
3005 // Use a linked hash set to ensure order is preserved and
3006 // fields from common super interfaces are not duplicated
3007 LinkedHashSet<Field> fields = new LinkedHashSet<>();
3008
3009 // Local fields
3010 addAll(fields, privateGetDeclaredFields(true));
3011
3012 // Direct superinterfaces, recursively
3013 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
3014 addAll(fields, si.privateGetPublicFields());
3015 }
3016
3017 // Direct superclass, recursively
3018 Class<?> sc = getSuperclass();
3019 if (sc != null) {
3020 addAll(fields, sc.privateGetPublicFields());
3021 }
3022
3023 res = fields.toArray(new Field[0]);
3024 rd.publicFields = res;
3025 return res;
3026 }
3027
3028 private static void addAll(Collection<Field> c, Field[] o) {
3029 for (Field f : o) {
3030 c.add(f);
3031 }
3032 }
3033
3034
3035 //
3036 //
3037 // java.lang.reflect.Constructor handling
3038 //
3039 //
3040
3041 // Returns an array of "root" constructors. These Constructor
3042 // objects must NOT be propagated to the outside world, but must
3043 // instead be copied via ReflectionFactory.copyConstructor.
3044 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3045 Constructor<T>[] res;
3046 ReflectionData<T> rd = reflectionData();
3047 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3048 if (res != null) return res;
3049 // No cached value available; request value from VM
3050 if (isInterface()) {
3051 @SuppressWarnings("unchecked")
3052 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3053 res = temporaryRes;
3054 } else {
3055 res = getDeclaredConstructors0(publicOnly);
3056 }
3057 if (publicOnly) {
3058 rd.publicConstructors = res;
3059 } else {
3060 rd.declaredConstructors = res;
3061 }
3062 return res;
3063 }
3064
3065 //
3066 //
3067 // java.lang.reflect.Method handling
3068 //
3069 //
3070
3071 // Returns an array of "root" methods. These Method objects must NOT
3072 // be propagated to the outside world, but must instead be copied
3073 // via ReflectionFactory.copyMethod.
3074 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3075 Method[] res;
3076 ReflectionData<T> rd = reflectionData();
3077 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3078 if (res != null) return res;
3079 // No cached value available; request value from VM
3080 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3081 if (publicOnly) {
3082 rd.declaredPublicMethods = res;
3083 } else {
3084 rd.declaredMethods = res;
3085 }
3086 return res;
3087 }
3088
3089 // Returns an array of "root" methods. These Method objects must NOT
3090 // be propagated to the outside world, but must instead be copied
3091 // via ReflectionFactory.copyMethod.
3092 private Method[] privateGetPublicMethods() {
3093 Method[] res;
3094 ReflectionData<T> rd = reflectionData();
3095 res = rd.publicMethods;
3096 if (res != null) return res;
3097
3098 // No cached value available; compute value recursively.
3099 // Start by fetching public declared methods...
3100 PublicMethods pms = new PublicMethods();
3101 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3102 pms.merge(m);
3103 }
3104 // ...then recur over superclass methods...
3105 Class<?> sc = getSuperclass();
3106 if (sc != null) {
3107 for (Method m : sc.privateGetPublicMethods()) {
3108 pms.merge(m);
3109 }
3110 }
3111 // ...and finally over direct superinterfaces.
3112 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3113 for (Method m : intf.privateGetPublicMethods()) {
3114 // static interface methods are not inherited
3115 if (!Modifier.isStatic(m.getModifiers())) {
3116 pms.merge(m);
3117 }
3118 }
3119 }
3120
3121 res = pms.toArray();
3122 rd.publicMethods = res;
3123 return res;
3124 }
3125
3126
3127 //
3128 // Helpers for fetchers of one field, method, or constructor
3129 //
3130
3131 // This method does not copy the returned Field object!
3132 private static Field searchFields(Field[] fields, String name) {
3133 for (Field field : fields) {
3134 if (field.getName().equals(name)) {
3135 return field;
3136 }
3137 }
3138 return null;
3139 }
3140
3141 // Returns a "root" Field object. This Field object must NOT
3142 // be propagated to the outside world, but must instead be copied
3143 // via ReflectionFactory.copyField.
3144 private Field getField0(String name) {
3145 // Note: the intent is that the search algorithm this routine
3146 // uses be equivalent to the ordering imposed by
3147 // privateGetPublicFields(). It fetches only the declared
3148 // public fields for each class, however, to reduce the number
3149 // of Field objects which have to be created for the common
3150 // case where the field being requested is declared in the
3151 // class which is being queried.
3152 Field res;
3153 // Search declared public fields
3154 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3155 return res;
3156 }
3157 // Direct superinterfaces, recursively
3158 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3159 for (Class<?> c : interfaces) {
3160 if ((res = c.getField0(name)) != null) {
3161 return res;
3162 }
3163 }
3164 // Direct superclass, recursively
3165 if (!isInterface()) {
3166 Class<?> c = getSuperclass();
3167 if (c != null) {
3168 if ((res = c.getField0(name)) != null) {
3169 return res;
3170 }
3171 }
3172 }
3173 return null;
3174 }
3175
3176 // This method does not copy the returned Method object!
3177 private static Method searchMethods(Method[] methods,
3178 String name,
3179 Class<?>[] parameterTypes)
3180 {
3181 ReflectionFactory fact = getReflectionFactory();
3182 Method res = null;
3183 for (Method m : methods) {
3184 if (m.getName().equals(name)
3185 && arrayContentsEq(parameterTypes,
3186 fact.getExecutableSharedParameterTypes(m))
3187 && (res == null
3188 || (res.getReturnType() != m.getReturnType()
3189 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3190 res = m;
3191 }
3192 return res;
3193 }
3194
3195 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3196
3197 // Returns a "root" Method object. This Method object must NOT
3198 // be propagated to the outside world, but must instead be copied
3199 // via ReflectionFactory.copyMethod.
3200 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3201 PublicMethods.MethodList res = getMethodsRecursive(
3202 name,
3203 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3204 /* includeStatic */ true, /* publicOnly */ true);
3205 return res == null ? null : res.getMostSpecific();
3206 }
3207
3208 // Returns a list of "root" Method objects. These Method objects must NOT
3209 // be propagated to the outside world, but must instead be copied
3210 // via ReflectionFactory.copyMethod.
3211 private PublicMethods.MethodList getMethodsRecursive(String name,
3212 Class<?>[] parameterTypes,
3213 boolean includeStatic,
3214 boolean publicOnly) {
3215 // 1st check declared methods
3216 Method[] methods = privateGetDeclaredMethods(publicOnly);
3217 PublicMethods.MethodList res = PublicMethods.MethodList
3218 .filter(methods, name, parameterTypes, includeStatic);
3219 // if there is at least one match among declared methods, we need not
3220 // search any further as such match surely overrides matching methods
3221 // declared in superclass(es) or interface(s).
3222 if (res != null) {
3223 return res;
3224 }
3225
3226 // if there was no match among declared methods,
3227 // we must consult the superclass (if any) recursively...
3228 Class<?> sc = getSuperclass();
3229 if (sc != null) {
3230 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3231 }
3232
3233 // ...and coalesce the superclass methods with methods obtained
3234 // from directly implemented interfaces excluding static methods...
3235 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3236 res = PublicMethods.MethodList.merge(
3237 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3238 }
3239
3240 return res;
3241 }
3242
3243 // Returns a "root" Constructor object. This Constructor object must NOT
3244 // be propagated to the outside world, but must instead be copied
3245 // via ReflectionFactory.copyConstructor.
3246 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3247 int which) throws NoSuchMethodException
3248 {
3249 ReflectionFactory fact = getReflectionFactory();
3250 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3251 for (Constructor<T> constructor : constructors) {
3252 if (arrayContentsEq(parameterTypes,
3253 fact.getExecutableSharedParameterTypes(constructor))) {
3254 return constructor;
3255 }
3256 }
3257 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3258 }
3259
3260 //
3261 // Other helpers and base implementation
3262 //
3263
3264 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3265 if (a1 == null) {
3266 return a2 == null || a2.length == 0;
3267 }
3268
3269 if (a2 == null) {
3270 return a1.length == 0;
3271 }
3272
3273 if (a1.length != a2.length) {
3274 return false;
3275 }
3276
3277 for (int i = 0; i < a1.length; i++) {
3278 if (a1[i] != a2[i]) {
3279 return false;
3280 }
3281 }
3282
3283 return true;
3284 }
3285
3286 private static Field[] copyFields(Field[] arg) {
3287 Field[] out = new Field[arg.length];
3288 ReflectionFactory fact = getReflectionFactory();
3289 for (int i = 0; i < arg.length; i++) {
3290 out[i] = fact.copyField(arg[i]);
3291 }
3292 return out;
3293 }
3294
3295 private static Method[] copyMethods(Method[] arg) {
3296 Method[] out = new Method[arg.length];
3297 ReflectionFactory fact = getReflectionFactory();
3298 for (int i = 0; i < arg.length; i++) {
3299 out[i] = fact.copyMethod(arg[i]);
3300 }
3301 return out;
3302 }
3303
3304 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3305 Constructor<U>[] out = arg.clone();
3306 ReflectionFactory fact = getReflectionFactory();
3307 for (int i = 0; i < out.length; i++) {
3308 out[i] = fact.copyConstructor(out[i]);
3309 }
3310 return out;
3311 }
3312
3313 private native Field[] getDeclaredFields0(boolean publicOnly);
3314 private native Method[] getDeclaredMethods0(boolean publicOnly);
3315 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3316 private native Class<?>[] getDeclaredClasses0();
3317
3318 /*
3319 * Returns an array containing the components of the Record attribute,
3320 * or null if the attribute is not present.
3321 *
3322 * Note that this method returns non-null array on a class with
3323 * the Record attribute even if this class is not a record.
3324 */
3325 private native RecordComponent[] getRecordComponents0();
3326 private native boolean isRecord0();
3327
3328 /**
3329 * Helper method to get the method name from arguments.
3330 */
3331 private String methodToString(String name, Class<?>[] argTypes) {
3332 return getName() + '.' + name +
3333 ((argTypes == null || argTypes.length == 0) ?
3334 "()" :
3335 Arrays.stream(argTypes)
3336 .map(c -> c == null ? "null" : c.getName())
3337 .collect(Collectors.joining(",", "(", ")")));
3338 }
3339
3340 /** use serialVersionUID from JDK 1.1 for interoperability */
3341 @java.io.Serial
3342 private static final long serialVersionUID = 3206093459760846163L;
3343
3344
3345 /**
3346 * Class Class is special cased within the Serialization Stream Protocol.
3347 *
3348 * A Class instance is written initially into an ObjectOutputStream in the
3349 * following format:
3350 * <pre>
3351 * {@code TC_CLASS} ClassDescriptor
3352 * A ClassDescriptor is a special cased serialization of
3353 * a {@code java.io.ObjectStreamClass} instance.
3354 * </pre>
3355 * A new handle is generated for the initial time the class descriptor
3356 * is written into the stream. Future references to the class descriptor
3357 * are written as references to the initial class descriptor instance.
3358 *
3359 * @see java.io.ObjectStreamClass
3360 */
3361 @java.io.Serial
3362 private static final ObjectStreamField[] serialPersistentFields =
3363 new ObjectStreamField[0];
3364
3365
3366 /**
3367 * Returns the assertion status that would be assigned to this
3368 * class if it were to be initialized at the time this method is invoked.
3369 * If this class has had its assertion status set, the most recent
3370 * setting will be returned; otherwise, if any package default assertion
3371 * status pertains to this class, the most recent setting for the most
3372 * specific pertinent package default assertion status is returned;
3373 * otherwise, if this class is not a system class (i.e., it has a
3374 * class loader) its class loader's default assertion status is returned;
3375 * otherwise, the system class default assertion status is returned.
3376 *
3377 * @apiNote
3378 * Few programmers will have any need for this method; it is provided
3379 * for the benefit of the JDK itself. (It allows a class to determine at
3380 * the time that it is initialized whether assertions should be enabled.)
3381 * Note that this method is not guaranteed to return the actual
3382 * assertion status that was (or will be) associated with the specified
3383 * class when it was (or will be) initialized.
3384 *
3385 * @return the desired assertion status of the specified class.
3386 * @see java.lang.ClassLoader#setClassAssertionStatus
3387 * @see java.lang.ClassLoader#setPackageAssertionStatus
3388 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3389 * @since 1.4
3390 */
3391 public boolean desiredAssertionStatus() {
3392 ClassLoader loader = classLoader;
3393 // If the loader is null this is a system class, so ask the VM
3394 if (loader == null)
3395 return desiredAssertionStatus0(this);
3396
3397 // If the classloader has been initialized with the assertion
3398 // directives, ask it. Otherwise, ask the VM.
3399 synchronized(loader.assertionLock) {
3400 if (loader.classAssertionStatus != null) {
3401 return loader.desiredAssertionStatus(getName());
3402 }
3403 }
3404 return desiredAssertionStatus0(this);
3405 }
3406
3407 // Retrieves the desired assertion status of this class from the VM
3408 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3409
3410 /**
3411 * Returns true if and only if this class was declared as an enum in the
3412 * source code.
3413 *
3414 * Note that {@link java.lang.Enum} is not itself an enum class.
3415 *
3416 * Also note that if an enum constant is declared with a class body,
3417 * the class of that enum constant object is an anonymous class
3418 * and <em>not</em> the class of the declaring enum class. The
3419 * {@link Enum#getDeclaringClass} method of an enum constant can
3420 * be used to get the class of the enum class declaring the
3421 * constant.
3422 *
3423 * @return true if and only if this class was declared as an enum in the
3424 * source code
3425 * @since 1.5
3426 * @jls 8.9.1 Enum Constants
3427 */
3428 public boolean isEnum() {
3429 // An enum must both directly extend java.lang.Enum and have
3430 // the ENUM bit set; classes for specialized enum constants
3431 // don't do the former.
3432 return (this.getModifiers() & ENUM) != 0 &&
3433 this.getSuperclass() == java.lang.Enum.class;
3434 }
3435
3436 /**
3437 * Returns {@code true} if and only if this class is a record class.
3438 *
3439 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3440 * class is {@code java.lang.Record}. A record class is {@linkplain
3441 * Modifier#FINAL final}. A record class has (possibly zero) record
3442 * components; {@link #getRecordComponents()} returns a non-null but
3443 * possibly empty value for a record.
3444 *
3445 * <p> Note that class {@link Record} is not a record class and thus
3446 * invoking this method on class {@code Record} returns {@code false}.
3447 *
3448 * @return true if and only if this class is a record class, otherwise false
3449 * @jls 8.10 Record Classes
3450 * @since 16
3451 */
3452 public boolean isRecord() {
3453 // this superclass and final modifier check is not strictly necessary
3454 // they are intrinsified and serve as a fast-path check
3455 return getSuperclass() == java.lang.Record.class &&
3456 (this.getModifiers() & Modifier.FINAL) != 0 &&
3457 isRecord0();
3458 }
3459
3460 // Fetches the factory for reflective objects
3461 private static ReflectionFactory getReflectionFactory() {
3462 var factory = reflectionFactory;
3463 if (factory != null) {
3464 return factory;
3465 }
3466 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3467 }
3468 private static ReflectionFactory reflectionFactory;
3469
3470 /**
3471 * When CDS is enabled, the Class class may be aot-initialized. However,
3472 * we can't archive reflectionFactory, so we reset it to null, so it
3473 * will be allocated again at runtime.
3474 */
3475 private static void resetArchivedStates() {
3476 reflectionFactory = 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 *
3483 * @return an array containing the values comprising the enum class
3484 * represented by this {@code Class} object in the order they're
3485 * declared, or null if this {@code Class} object does not
3486 * represent an enum class
3487 * @since 1.5
3488 * @jls 8.9.1 Enum Constants
3489 */
3490 public T[] getEnumConstants() {
3491 T[] values = getEnumConstantsShared();
3492 return (values != null) ? values.clone() : null;
3493 }
3494
3495 /**
3496 * Returns the elements of this enum class or null if this
3497 * Class object does not represent an enum class;
3498 * identical to getEnumConstants except that the result is
3499 * uncloned, cached, and shared by all callers.
3500 */
3501 T[] getEnumConstantsShared() {
3502 T[] constants = enumConstants;
3503 if (constants == null) {
3504 if (!isEnum()) return null;
3505 try {
3506 final Method values = getMethod("values");
3507 values.setAccessible(true);
3508 @SuppressWarnings("unchecked")
3509 T[] temporaryConstants = (T[])values.invoke(null);
3510 enumConstants = constants = temporaryConstants;
3511 }
3512 // These can happen when users concoct enum-like classes
3513 // that don't comply with the enum spec.
3514 catch (InvocationTargetException | NoSuchMethodException |
3515 IllegalAccessException | NullPointerException |
3516 ClassCastException ex) { return null; }
3517 }
3518 return constants;
3519 }
3520 private transient volatile T[] enumConstants;
3521
3522 /**
3523 * Returns a map from simple name to enum constant. This package-private
3524 * method is used internally by Enum to implement
3525 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3526 * efficiently. Note that the map is returned by this method is
3527 * created lazily on first use. Typically it won't ever get created.
3528 */
3529 Map<String, T> enumConstantDirectory() {
3530 Map<String, T> directory = enumConstantDirectory;
3531 if (directory == null) {
3532 T[] universe = getEnumConstantsShared();
3533 if (universe == null)
3534 throw new IllegalArgumentException(
3535 getName() + " is not an enum class");
3536 directory = HashMap.newHashMap(universe.length);
3537 for (T constant : universe) {
3538 directory.put(((Enum<?>)constant).name(), constant);
3539 }
3540 enumConstantDirectory = directory;
3541 }
3542 return directory;
3543 }
3544 private transient volatile Map<String, T> enumConstantDirectory;
3545
3546 /**
3547 * Casts an object to the class or interface represented
3548 * by this {@code Class} object.
3549 *
3550 * @param obj the object to be cast
3551 * @return the object after casting, or null if obj is null
3552 *
3553 * @throws ClassCastException if the object is not
3554 * null and is not assignable to the type T.
3555 *
3556 * @since 1.5
3557 */
3558 @SuppressWarnings("unchecked")
3559 @IntrinsicCandidate
3560 public T cast(Object obj) {
3561 if (obj != null && !isInstance(obj))
3562 throw new ClassCastException(cannotCastMsg(obj));
3563 return (T) obj;
3564 }
3565
3566 private String cannotCastMsg(Object obj) {
3567 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3568 }
3569
3570 /**
3571 * Casts this {@code Class} object to represent a subclass of the class
3572 * represented by the specified class object. Checks that the cast
3573 * is valid, and throws a {@code ClassCastException} if it is not. If
3574 * this method succeeds, it always returns a reference to this {@code Class} object.
3575 *
3576 * <p>This method is useful when a client needs to "narrow" the type of
3577 * a {@code Class} object to pass it to an API that restricts the
3578 * {@code Class} objects that it is willing to accept. A cast would
3579 * generate a compile-time warning, as the correctness of the cast
3580 * could not be checked at runtime (because generic types are implemented
3581 * by erasure).
3582 *
3583 * @param <U> the type to cast this {@code Class} object to
3584 * @param clazz the class of the type to cast this {@code Class} object to
3585 * @return this {@code Class} object, cast to represent a subclass of
3586 * the specified class object.
3587 * @throws ClassCastException if this {@code Class} object does not
3588 * represent a subclass of the specified class (here "subclass" includes
3589 * the class itself).
3590 * @since 1.5
3591 */
3592 @SuppressWarnings("unchecked")
3593 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3594 if (clazz.isAssignableFrom(this))
3595 return (Class<? extends U>) this;
3596 else
3597 throw new ClassCastException(this.toString());
3598 }
3599
3600 /**
3601 * {@inheritDoc}
3602 * <p>Note that any annotation returned by this method is a
3603 * declaration annotation.
3604 *
3605 * @throws NullPointerException {@inheritDoc}
3606 * @since 1.5
3607 */
3608 @Override
3609 @SuppressWarnings("unchecked")
3610 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3611 Objects.requireNonNull(annotationClass);
3612
3613 return (A) annotationData().annotations.get(annotationClass);
3614 }
3615
3616 /**
3617 * {@inheritDoc}
3618 * @throws NullPointerException {@inheritDoc}
3619 * @since 1.5
3620 */
3621 @Override
3622 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3623 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3624 }
3625
3626 /**
3627 * {@inheritDoc}
3628 * <p>Note that any annotations returned by this method are
3629 * declaration annotations.
3630 *
3631 * @throws NullPointerException {@inheritDoc}
3632 * @since 1.8
3633 */
3634 @Override
3635 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3636 Objects.requireNonNull(annotationClass);
3637
3638 AnnotationData annotationData = annotationData();
3639 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3640 this,
3641 annotationClass);
3642 }
3643
3644 /**
3645 * {@inheritDoc}
3646 * <p>Note that any annotations returned by this method are
3647 * declaration annotations.
3648 *
3649 * @since 1.5
3650 */
3651 @Override
3652 public Annotation[] getAnnotations() {
3653 return AnnotationParser.toArray(annotationData().annotations);
3654 }
3655
3656 /**
3657 * {@inheritDoc}
3658 * <p>Note that any annotation returned by this method is a
3659 * declaration annotation.
3660 *
3661 * @throws NullPointerException {@inheritDoc}
3662 * @since 1.8
3663 */
3664 @Override
3665 @SuppressWarnings("unchecked")
3666 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3667 Objects.requireNonNull(annotationClass);
3668
3669 return (A) annotationData().declaredAnnotations.get(annotationClass);
3670 }
3671
3672 /**
3673 * {@inheritDoc}
3674 * <p>Note that any annotations returned by this method are
3675 * declaration annotations.
3676 *
3677 * @throws NullPointerException {@inheritDoc}
3678 * @since 1.8
3679 */
3680 @Override
3681 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3682 Objects.requireNonNull(annotationClass);
3683
3684 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3685 annotationClass);
3686 }
3687
3688 /**
3689 * {@inheritDoc}
3690 * <p>Note that any annotations returned by this method are
3691 * declaration annotations.
3692 *
3693 * @since 1.5
3694 */
3695 @Override
3696 public Annotation[] getDeclaredAnnotations() {
3697 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3698 }
3699
3700 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3701 private static class AnnotationData {
3702 final Map<Class<? extends Annotation>, Annotation> annotations;
3703 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3704
3705 // Value of classRedefinedCount when we created this AnnotationData instance
3706 final int redefinedCount;
3707
3708 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3709 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3710 int redefinedCount) {
3711 this.annotations = annotations;
3712 this.declaredAnnotations = declaredAnnotations;
3713 this.redefinedCount = redefinedCount;
3714 }
3715 }
3716
3717 // Annotations cache
3718 @SuppressWarnings("UnusedDeclaration")
3719 private transient volatile AnnotationData annotationData;
3720
3721 private AnnotationData annotationData() {
3722 while (true) { // retry loop
3723 AnnotationData annotationData = this.annotationData;
3724 int classRedefinedCount = this.classRedefinedCount;
3725 if (annotationData != null &&
3726 annotationData.redefinedCount == classRedefinedCount) {
3727 return annotationData;
3728 }
3729 // null or stale annotationData -> optimistically create new instance
3730 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3731 // try to install it
3732 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3733 // successfully installed new AnnotationData
3734 return newAnnotationData;
3735 }
3736 }
3737 }
3738
3739 private AnnotationData createAnnotationData(int classRedefinedCount) {
3740 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3741 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3742 Class<?> superClass = getSuperclass();
3743 Map<Class<? extends Annotation>, Annotation> annotations = null;
3744 if (superClass != null) {
3745 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3746 superClass.annotationData().annotations;
3747 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3748 Class<? extends Annotation> annotationClass = e.getKey();
3749 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3750 if (annotations == null) { // lazy construction
3751 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3752 declaredAnnotations.size(),
3753 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3754 )
3755 );
3756 }
3757 annotations.put(annotationClass, e.getValue());
3758 }
3759 }
3760 }
3761 if (annotations == null) {
3762 // no inherited annotations -> share the Map with declaredAnnotations
3763 annotations = declaredAnnotations;
3764 } else {
3765 // at least one inherited annotation -> declared may override inherited
3766 annotations.putAll(declaredAnnotations);
3767 }
3768 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3769 }
3770
3771 // Annotation interfaces cache their internal (AnnotationType) form
3772
3773 @SuppressWarnings("UnusedDeclaration")
3774 private transient volatile AnnotationType annotationType;
3775
3776 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3777 return Atomic.casAnnotationType(this, oldType, newType);
3778 }
3779
3780 AnnotationType getAnnotationType() {
3781 return annotationType;
3782 }
3783
3784 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3785 return annotationData().declaredAnnotations;
3786 }
3787
3788 /* Backing store of user-defined values pertaining to this class.
3789 * Maintained by the ClassValue class.
3790 */
3791 transient ClassValue.ClassValueMap classValueMap;
3792
3793 /**
3794 * Returns an {@code AnnotatedType} object that represents the use of a
3795 * type to specify the superclass of the entity represented by this {@code
3796 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3797 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3798 * Foo.)
3799 *
3800 * <p> If this {@code Class} object represents a class whose declaration
3801 * does not explicitly indicate an annotated superclass, then the return
3802 * value is an {@code AnnotatedType} object representing an element with no
3803 * annotations.
3804 *
3805 * <p> If this {@code Class} represents either the {@code Object} class, an
3806 * interface type, an array type, a primitive type, or void, the return
3807 * value is {@code null}.
3808 *
3809 * @return an object representing the superclass
3810 * @since 1.8
3811 */
3812 public AnnotatedType getAnnotatedSuperclass() {
3813 if (this == Object.class ||
3814 isInterface() ||
3815 isArray() ||
3816 isPrimitive() ||
3817 this == Void.TYPE) {
3818 return null;
3819 }
3820
3821 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3822 }
3823
3824 /**
3825 * Returns an array of {@code AnnotatedType} objects that represent the use
3826 * of types to specify superinterfaces of the entity represented by this
3827 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3828 * superinterface in '... implements Foo' is distinct from the
3829 * <em>declaration</em> of interface Foo.)
3830 *
3831 * <p> If this {@code Class} object represents a class, the return value is
3832 * an array containing objects representing the uses of interface types to
3833 * specify interfaces implemented by the class. The order of the objects in
3834 * the array corresponds to the order of the interface types used in the
3835 * 'implements' clause of the declaration of this {@code Class} object.
3836 *
3837 * <p> If this {@code Class} object represents an interface, the return
3838 * value is an array containing objects representing the uses of interface
3839 * types to specify interfaces directly extended by the interface. The
3840 * order of the objects in the array corresponds to the order of the
3841 * interface types used in the 'extends' clause of the declaration of this
3842 * {@code Class} object.
3843 *
3844 * <p> If this {@code Class} object represents a class or interface whose
3845 * declaration does not explicitly indicate any annotated superinterfaces,
3846 * the return value is an array of length 0.
3847 *
3848 * <p> If this {@code Class} object represents either the {@code Object}
3849 * class, an array type, a primitive type, or void, the return value is an
3850 * array of length 0.
3851 *
3852 * @return an array representing the superinterfaces
3853 * @since 1.8
3854 */
3855 public AnnotatedType[] getAnnotatedInterfaces() {
3856 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3857 }
3858
3859 private native Class<?> getNestHost0();
3860
3861 /**
3862 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3863 * or interface represented by this {@code Class} object belongs.
3864 * Every class and interface belongs to exactly one nest.
3865 *
3866 * If the nest host of this class or interface has previously
3867 * been determined, then this method returns the nest host.
3868 * If the nest host of this class or interface has
3869 * not previously been determined, then this method determines the nest
3870 * host using the algorithm of JVMS 5.4.4, and returns it.
3871 *
3872 * Often, a class or interface belongs to a nest consisting only of itself,
3873 * in which case this method returns {@code this} to indicate that the class
3874 * or interface is the nest host.
3875 *
3876 * <p>If this {@code Class} object represents a primitive type, an array type,
3877 * or {@code void}, then this method returns {@code this},
3878 * indicating that the represented entity belongs to the nest consisting only of
3879 * itself, and is the nest host.
3880 *
3881 * @return the nest host of this class or interface
3882 *
3883 * @since 11
3884 * @jvms 4.7.28 The {@code NestHost} Attribute
3885 * @jvms 4.7.29 The {@code NestMembers} Attribute
3886 * @jvms 5.4.4 Access Control
3887 */
3888 public Class<?> getNestHost() {
3889 if (isPrimitive() || isArray()) {
3890 return this;
3891 }
3892 return getNestHost0();
3893 }
3894
3895 /**
3896 * Determines if the given {@code Class} is a nestmate of the
3897 * class or interface represented by this {@code Class} object.
3898 * Two classes or interfaces are nestmates
3899 * if they have the same {@linkplain #getNestHost() nest host}.
3900 *
3901 * @param c the class to check
3902 * @return {@code true} if this class and {@code c} are members of
3903 * the same nest; and {@code false} otherwise.
3904 *
3905 * @since 11
3906 */
3907 public boolean isNestmateOf(Class<?> c) {
3908 if (this == c) {
3909 return true;
3910 }
3911 if (isPrimitive() || isArray() ||
3912 c.isPrimitive() || c.isArray()) {
3913 return false;
3914 }
3915
3916 return getNestHost() == c.getNestHost();
3917 }
3918
3919 private native Class<?>[] getNestMembers0();
3920
3921 /**
3922 * Returns an array containing {@code Class} objects representing all the
3923 * classes and interfaces that are members of the nest to which the class
3924 * or interface represented by this {@code Class} object belongs.
3925 *
3926 * First, this method obtains the {@linkplain #getNestHost() nest host},
3927 * {@code H}, of the nest to which the class or interface represented by
3928 * this {@code Class} object belongs. The zeroth element of the returned
3929 * array is {@code H}.
3930 *
3931 * Then, for each class or interface {@code C} which is recorded by {@code H}
3932 * as being a member of its nest, this method attempts to obtain the {@code Class}
3933 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3934 * loader} of the current {@code Class} object), and then obtains the
3935 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3936 * The classes and interfaces which are recorded by {@code H} as being members
3937 * of its nest, and for which {@code H} can be determined as their nest host,
3938 * are indicated by subsequent elements of the returned array. The order of
3939 * such elements is unspecified. Duplicates are permitted.
3940 *
3941 * <p>If this {@code Class} object represents a primitive type, an array type,
3942 * or {@code void}, then this method returns a single-element array containing
3943 * {@code this}.
3944 *
3945 * @apiNote
3946 * The returned array includes only the nest members recorded in the {@code NestMembers}
3947 * attribute, and not any hidden classes that were added to the nest via
3948 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3949 * Lookup::defineHiddenClass}.
3950 *
3951 * @return an array of all classes and interfaces in the same nest as
3952 * this class or interface
3953 *
3954 * @since 11
3955 * @see #getNestHost()
3956 * @jvms 4.7.28 The {@code NestHost} Attribute
3957 * @jvms 4.7.29 The {@code NestMembers} Attribute
3958 */
3959 public Class<?>[] getNestMembers() {
3960 if (isPrimitive() || isArray()) {
3961 return new Class<?>[] { this };
3962 }
3963 Class<?>[] members = getNestMembers0();
3964 // Can't actually enable this due to bootstrapping issues
3965 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3966 return members;
3967 }
3968
3969 /**
3970 * Returns the descriptor string of the entity (class, interface, array class,
3971 * primitive type, or {@code void}) represented by this {@code Class} object.
3972 *
3973 * <p> If this {@code Class} object represents a class or interface,
3974 * not an array class, then:
3975 * <ul>
3976 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3977 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3978 * for the class or interface. Calling
3979 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3980 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3981 * describing this class or interface.
3982 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3983 * then the result is a string of the form:
3984 * <blockquote>
3985 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3986 * </blockquote>
3987 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3988 * encoded in internal form indicated by the {@code class} file passed to
3989 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3990 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3991 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3992 * The result string is not a type descriptor.
3993 * </ul>
3994 *
3995 * <p> If this {@code Class} object represents an array class, then
3996 * the result is a string consisting of one or more '{@code [}' characters
3997 * representing the depth of the array nesting, followed by the
3998 * descriptor string of the element type.
3999 * <ul>
4000 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
4001 * or interface, then this array class can be described nominally.
4002 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
4003 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
4004 * describing this array class.
4005 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
4006 * interface, then this array class cannot be described nominally.
4007 * The result string is not a type descriptor.
4008 * </ul>
4009 *
4010 * <p> If this {@code Class} object represents a primitive type or
4011 * {@code void}, then the result is a field descriptor string which
4012 * is a one-letter code corresponding to a primitive type or {@code void}
4013 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
4014 *
4015 * @return the descriptor string for this {@code Class} object
4016 * @jvms 4.3.2 Field Descriptors
4017 * @since 12
4018 */
4019 @Override
4020 public String descriptorString() {
4021 if (isPrimitive())
4022 return Wrapper.forPrimitiveType(this).basicTypeString();
4023
4024 if (isArray()) {
4025 return "[".concat(componentType.descriptorString());
4026 } else if (isHidden()) {
4027 String name = getName();
4028 int index = name.indexOf('/');
4029 return new StringBuilder(name.length() + 2)
4030 .append('L')
4031 .append(name.substring(0, index).replace('.', '/'))
4032 .append('.')
4033 .append(name, index + 1, name.length())
4034 .append(';')
4035 .toString();
4036 } else {
4037 String name = getName().replace('.', '/');
4038 return StringConcatHelper.concat("L", name, ";");
4039 }
4040 }
4041
4042 /**
4043 * Returns the component type of this {@code Class}, if it describes
4044 * an array type, or {@code null} otherwise.
4045 *
4046 * @implSpec
4047 * Equivalent to {@link Class#getComponentType()}.
4048 *
4049 * @return a {@code Class} describing the component type, or {@code null}
4050 * if this {@code Class} does not describe an array type
4051 * @since 12
4052 */
4053 @Override
4054 public Class<?> componentType() {
4055 return getComponentType();
4056 }
4057
4058 /**
4059 * Returns a {@code Class} for an array type whose component type
4060 * is described by this {@linkplain Class}.
4061 *
4062 * @throws UnsupportedOperationException if this component type is {@linkplain
4063 * Void#TYPE void} or if the number of dimensions of the resulting array
4064 * type would exceed 255.
4065 * @return a {@code Class} describing the array type
4066 * @jvms 4.3.2 Field Descriptors
4067 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4068 * @since 12
4069 */
4070 @Override
4071 public Class<?> arrayType() {
4072 try {
4073 return Array.newInstance(this, 0).getClass();
4074 } catch (IllegalArgumentException iae) {
4075 throw new UnsupportedOperationException(iae);
4076 }
4077 }
4078
4079 /**
4080 * Returns a nominal descriptor for this instance, if one can be
4081 * constructed, or an empty {@link Optional} if one cannot be.
4082 *
4083 * @return An {@link Optional} containing the resulting nominal descriptor,
4084 * or an empty {@link Optional} if one cannot be constructed.
4085 * @since 12
4086 */
4087 @Override
4088 public Optional<ClassDesc> describeConstable() {
4089 Class<?> c = isArray() ? elementType() : this;
4090 return c.isHidden() ? Optional.empty()
4091 : Optional.of(ConstantUtils.classDesc(this));
4092 }
4093
4094 /**
4095 * Returns {@code true} if and only if the underlying class is a hidden class.
4096 *
4097 * @return {@code true} if and only if this class is a hidden class.
4098 *
4099 * @since 15
4100 * @see MethodHandles.Lookup#defineHiddenClass
4101 * @see Class##hiddenClasses Hidden Classes
4102 */
4103 @IntrinsicCandidate
4104 public native boolean isHidden();
4105
4106 /**
4107 * Returns an array containing {@code Class} objects representing the
4108 * direct subinterfaces or subclasses permitted to extend or
4109 * implement this class or interface if it is sealed. The order of such elements
4110 * is unspecified. The array is empty if this sealed class or interface has no
4111 * permitted subclass. If this {@code Class} object represents a primitive type,
4112 * {@code void}, an array type, or a class or interface that is not sealed,
4113 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4114 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4115 * returns a non-null value.
4116 *
4117 * For each class or interface {@code C} which is recorded as a permitted
4118 * direct subinterface or subclass of this class or interface,
4119 * this method attempts to obtain the {@code Class}
4120 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4121 * loader} of the current {@code Class} object).
4122 * The {@code Class} objects which can be obtained and which are direct
4123 * subinterfaces or subclasses of this class or interface,
4124 * are indicated by elements of the returned array. If a {@code Class} object
4125 * cannot be obtained, it is silently ignored, and not included in the result
4126 * array.
4127 *
4128 * @return an array of {@code Class} objects of the permitted subclasses of this class
4129 * or interface, or {@code null} if this class or interface is not sealed.
4130 *
4131 * @jls 8.1 Class Declarations
4132 * @jls 9.1 Interface Declarations
4133 * @since 17
4134 */
4135 public Class<?>[] getPermittedSubclasses() {
4136 Class<?>[] subClasses;
4137 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4138 return null;
4139 }
4140 if (subClasses.length > 0) {
4141 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4142 subClasses = Arrays.stream(subClasses)
4143 .filter(this::isDirectSubType)
4144 .toArray(s -> new Class<?>[s]);
4145 }
4146 }
4147 return subClasses;
4148 }
4149
4150 private boolean isDirectSubType(Class<?> c) {
4151 if (isInterface()) {
4152 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4153 if (i == this) {
4154 return true;
4155 }
4156 }
4157 } else {
4158 return c.getSuperclass() == this;
4159 }
4160 return false;
4161 }
4162
4163 /**
4164 * Returns {@code true} if and only if this {@code Class} object represents
4165 * a sealed class or interface. If this {@code Class} object represents a
4166 * primitive type, {@code void}, or an array type, this method returns
4167 * {@code false}. A sealed class or interface has (possibly zero) permitted
4168 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4169 * possibly empty value for a sealed class or interface.
4170 *
4171 * @return {@code true} if and only if this {@code Class} object represents
4172 * a sealed class or interface.
4173 *
4174 * @jls 8.1 Class Declarations
4175 * @jls 9.1 Interface Declarations
4176 * @since 17
4177 */
4178 public boolean isSealed() {
4179 if (isArray() || isPrimitive()) {
4180 return false;
4181 }
4182 return getPermittedSubclasses() != null;
4183 }
4184
4185 private native Class<?>[] getPermittedSubclasses0();
4186
4187 /*
4188 * Return the class's major and minor class file version packed into an int.
4189 * The high order 16 bits contain the class's minor version. The low order
4190 * 16 bits contain the class's major version.
4191 *
4192 * If the class is an array type then the class file version of its element
4193 * type is returned. If the class is a primitive type then the latest class
4194 * file major version is returned and zero is returned for the minor version.
4195 */
4196 /* package-private */
4197 int getClassFileVersion() {
4198 Class<?> c = isArray() ? elementType() : this;
4199 return c.getClassFileVersion0();
4200 }
4201
4202 private native int getClassFileVersion0();
4203
4204 /**
4205 * Return the access flags as they were in the class's bytecode, including
4206 * the original setting of ACC_SUPER.
4207 *
4208 * If this {@code Class} object represents a primitive type or
4209 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
4210 * {@code FINAL}.
4211 * If this {@code Class} object represents an array type, return 0.
4212 */
4213 int getClassFileAccessFlags() {
4214 return classFileAccessFlags;
4215 }
4216
4217 // Validates the length of the class name and throws an exception if it exceeds the maximum allowed length.
4218 private static void validateClassNameLength(String name) throws ClassNotFoundException {
4219 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
4220 throw new ClassNotFoundException(
4221 "Class name length exceeds limit of "
4222 + ModifiedUtf.CONSTANT_POOL_UTF8_MAX_BYTES
4223 + ": " + name.substring(0,256) + "...");
4224 }
4225 }
4226 }