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.Wrapper;
92 import sun.reflect.generics.factory.CoreReflectionFactory;
93 import sun.reflect.generics.factory.GenericsFactory;
94 import sun.reflect.generics.repository.ClassRepository;
95 import sun.reflect.generics.repository.MethodRepository;
96 import sun.reflect.generics.repository.ConstructorRepository;
97 import sun.reflect.generics.scope.ClassScope;
98 import sun.reflect.annotation.*;
99
100 /**
101 * Instances of the class {@code Class} represent classes and
102 * interfaces in a running Java application. An enum class and a record
103 * class are kinds of class; an annotation interface is a kind of
104 * interface. Every array also belongs to a class that is reflected as
105 * a {@code Class} object that is shared by all arrays with the same
106 * element type and number of dimensions. The primitive Java types
107 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
108 * int}, {@code long}, {@code float}, and {@code double}), and the
109 * keyword {@code void} are also represented as {@code Class} objects.
110 *
111 * <p> {@code Class} has no public constructor. Instead a {@code Class}
112 * object is constructed automatically by the Java Virtual Machine when
113 * a class is derived from the bytes of a {@code class} file through
114 * the invocation of one of the following methods:
115 * <ul>
116 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
117 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
118 * java.lang.invoke.MethodHandles.Lookup::defineClass}
119 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
120 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
121 * </ul>
122 *
123 * <p> The methods of class {@code Class} expose many characteristics of a
124 * class or interface. Most characteristics are derived from the {@code class}
125 * file that the class loader passed to the Java Virtual Machine or
126 * from the {@code class} file passed to {@code Lookup::defineClass}
127 * or {@code Lookup::defineHiddenClass}.
128 * A few characteristics are determined by the class loading environment
129 * at run time, such as the module returned by {@link #getModule() getModule()}.
130 *
131 * <p> The following example uses a {@code Class} object to print the
132 * class name of an object:
133 *
134 * {@snippet lang="java" :
135 * void printClassName(Object obj) {
136 * System.out.println("The class of " + obj +
137 * " is " + obj.getClass().getName());
138 * }}
139 *
140 * It is also possible to get the {@code Class} object for a named
141 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
142 * (JLS {@jls 15.8.2}).
143 * For example:
144 *
145 * {@snippet lang="java" :
146 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
147 * }
148 *
149 * <p> Some methods of class {@code Class} expose whether the declaration of
150 * a class or interface in Java source code was <em>enclosed</em> within
151 * another declaration. Other methods describe how a class or interface
152 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
153 * classes and interfaces, in the same run-time package, that
154 * allow mutual access to their {@code private} members.
155 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
156 * (JVMS {@jvms 4.7.29}).
157 * One nestmate acts as the
158 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
159 * belong to the nest; each of them in turn records it as the nest host.
160 * The classes and interfaces which belong to a nest, including its host, are
161 * determined when
162 * {@code class} files are generated, for example, a Java compiler
163 * will typically record a top-level class as the host of a nest where the
164 * other members are the classes and interfaces whose declarations are
165 * enclosed within the top-level class declaration.
166 *
167 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
168 * A class or interface created by the invocation of
169 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
170 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
171 * class or interface.
172 * All kinds of class, including enum classes and record classes, may be
173 * hidden classes; all kinds of interface, including annotation interfaces,
174 * may be hidden interfaces.
175 *
176 * The {@linkplain #getName() name of a hidden class or interface} is
177 * not a {@linkplain ClassLoader##binary-name binary name},
178 * which means the following:
179 * <ul>
180 * <li>A hidden class or interface cannot be referenced by the constant pools
181 * of other classes and interfaces.
182 * <li>A hidden class or interface cannot be described in
183 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
184 * {@link #describeConstable() Class::describeConstable},
185 * {@link ClassDesc#of(String) ClassDesc::of}, or
186 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
187 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
188 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
189 * </ul>
190 *
191 * A hidden class or interface is never an array class, but may be
192 * the element type of an array. In all other respects, the fact that
193 * a class or interface is hidden has no bearing on the characteristics
194 * exposed by the methods of class {@code Class}.
195 *
196 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
197 *
198 * Conventionally, a Java compiler, starting from a source file for an
199 * implicitly declared class, say {@code HelloWorld.java}, creates a
200 * similarly-named {@code class} file, {@code HelloWorld.class}, where
201 * the class stored in that {@code class} file is named {@code
202 * "HelloWorld"}, matching the base names of the source and {@code
203 * class} files.
204 *
205 * For the {@code Class} object of an implicitly declared class {@code
206 * HelloWorld}, the methods to get the {@linkplain #getName name} and
207 * {@linkplain #getTypeName type name} return results
208 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
209 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
210 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
211 *
212 * @param <T> the type of the class modeled by this {@code Class}
213 * object. For example, the type of {@code String.class} is {@code
214 * Class<String>}. Use {@code Class<?>} if the class being modeled is
215 * unknown.
216 *
217 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
218 * @since 1.0
219 */
220 @AOTSafeClassInitializer
221 public final class Class<T> implements java.io.Serializable,
222 GenericDeclaration,
223 Type,
224 AnnotatedElement,
225 TypeDescriptor.OfField<Class<?>>,
226 Constable {
227 private static final int ANNOTATION = 0x00002000;
228 private static final int ENUM = 0x00004000;
229 private static final int SYNTHETIC = 0x00001000;
230
231 private static native void registerNatives();
232 static {
233 runtimeSetup();
234 }
235
236 /// No significant static final fields; [#resetArchivedStates()] handles
237 /// prevents storing [#reflectionFactory] into AOT image.
238 @AOTRuntimeSetup
239 private static void runtimeSetup() {
240 registerNatives();
241 }
242
243 /*
244 * Private constructor. Only the Java Virtual Machine creates Class objects.
245 * This constructor is not used and prevents the default constructor being
246 * generated.
247 */
248 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, char flags) {
249 // Initialize final field for classLoader. The initialization value of non-null
250 // prevents future JIT optimizations from assuming this final field is null.
251 // The following assignments are done directly by the VM without calling this constructor.
252 classLoader = loader;
253 componentType = arrayComponentType;
254 modifiers = mods;
255 protectionDomain = pd;
256 primitive = isPrim;
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, caller);
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, null);
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 Class<?> caller)
573 throws ClassNotFoundException;
574
575
576 /**
577 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
578 * binary name} in the given module.
579 *
580 * <p> This method attempts to locate and load the class or interface.
581 * It does not link the class, and does not run the class initializer.
582 * If the class is not found, this method returns {@code null}. </p>
583 *
584 * <p> If the class loader of the given module defines other modules and
585 * the given name is a class defined in a different module, this method
586 * returns {@code null} after the class is loaded. </p>
587 *
588 * <p> This method does not check whether the requested class is
589 * accessible to its caller. </p>
590 *
591 * @apiNote
592 * This method does not support loading of array types, unlike
593 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
594 * a binary name. This method returns {@code null} on failure rather than
595 * throwing a {@link ClassNotFoundException}, as is done by
596 * the {@link #forName(String, boolean, ClassLoader)} method.
597 *
598 * @param module A module
599 * @param name The {@linkplain ClassLoader##binary-name binary name}
600 * of the class
601 * @return {@code Class} object of the given name defined in the given module;
602 * {@code null} if not found.
603 *
604 * @throws NullPointerException if the given module or name is {@code null}
605 *
606 * @throws LinkageError if the linkage fails
607 *
608 * @jls 12.2 Loading of Classes and Interfaces
609 * @jls 12.3 Linking of Classes and Interfaces
610 * @since 9
611 */
612 public static Class<?> forName(Module module, String name) {
613 Objects.requireNonNull(module);
614 Objects.requireNonNull(name);
615 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
616 return null;
617 }
618
619 ClassLoader cl = module.getClassLoader();
620 if (cl != null) {
621 return cl.loadClass(module, name);
622 } else {
623 return BootLoader.loadClass(module, name);
624 }
625 }
626
627 /**
628 * {@return {@code true} if this {@code Class} object represents an identity class,
629 * otherwise {@code false}}
630 *
631 * <ul>
632 * <li>
633 * If this {@code Class} object represents an array type this method returns {@code true}.
634 * <li>
635 * If this {@code Class} object represents an interface, a primitive type,
636 * or {@code void} this method returns {@code false}.
637 * <li>
638 * For all other {@code Class} objects, this method returns {@code true} if either
639 * preview features are disabled or {@linkplain Modifier#IDENTITY} is set in the
640 * {@linkplain #getModifiers() class modifiers}.
641 * </ul>
642 * @see AccessFlag#IDENTITY
643 * @since Valhalla
644 */
645 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true)
646 public boolean isIdentity() {
647 if (isPrimitive()) {
648 return false;
649 } else if (PreviewFeatures.isEnabled()) {
650 return isArray() || Modifier.isIdentity(modifiers);
651 } else {
652 return !isInterface();
653 }
654 }
655
656 /**
657 * {@return {@code true} if this {@code Class} object represents a value class,
658 * otherwise {@code false}}
659 * <ul>
660 * <li>
661 * If this {@code Class} object represents an array type this method returns {@code false}.
662 * <li>
663 * If this {@code Class} object represents an interface, a primitive type,
664 * or {@code void} this method returns {@code true} only if preview features are enabled.
665 * <li>
666 * For all other {@code Class} objects, this method returns {@code true} only if
667 * preview features are enabled and {@linkplain Modifier#IDENTITY} is not set in the
668 * {@linkplain #getModifiers() class modifiers}.
669 * </ul>
670 * @see AccessFlag#IDENTITY
671 * @since Valhalla
672 */
673 @PreviewFeature(feature = PreviewFeature.Feature.VALUE_OBJECTS, reflective=true)
674 public boolean isValue() {
675 if (!PreviewFeatures.isEnabled()) {
676 return false;
677 }
678 return !isIdentity();
679 }
680
681 /**
682 * {@return the {@code Class} object associated with the
683 * {@linkplain #isPrimitive() primitive type} of the given name}
684 * If the argument is not the name of a primitive type, {@code
685 * null} is returned.
686 *
687 * @param primitiveName the name of the primitive type to find
688 *
689 * @throws NullPointerException if the argument is {@code null}
690 *
691 * @jls 4.2 Primitive Types and Values
692 * @jls 15.8.2 Class Literals
693 * @since 22
694 */
695 public static Class<?> forPrimitiveName(String primitiveName) {
696 return switch(primitiveName) {
697 // Integral types
698 case "int" -> int.class;
699 case "long" -> long.class;
700 case "short" -> short.class;
701 case "char" -> char.class;
702 case "byte" -> byte.class;
703
704 // Floating-point types
705 case "float" -> float.class;
706 case "double" -> double.class;
707
708 // Other types
709 case "boolean" -> boolean.class;
710 case "void" -> void.class;
711
712 default -> null;
713 };
714 }
715
716 /**
717 * Creates a new instance of the class represented by this {@code Class}
718 * object. The class is instantiated as if by a {@code new}
719 * expression with an empty argument list. The class is initialized if it
720 * has not already been initialized.
721 *
722 * @deprecated This method propagates any exception thrown by the
723 * nullary constructor, including a checked exception. Use of
724 * this method effectively bypasses the compile-time exception
725 * checking that would otherwise be performed by the compiler.
726 * The {@link
727 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
728 * Constructor.newInstance} method avoids this problem by wrapping
729 * any exception thrown by the constructor in a (checked) {@link
730 * java.lang.reflect.InvocationTargetException}.
731 *
732 * <p>The call
733 *
734 * {@snippet lang="java" :
735 * clazz.newInstance()
736 * }
737 *
738 * can be replaced by
739 *
740 * {@snippet lang="java" :
741 * clazz.getDeclaredConstructor().newInstance()
742 * }
743 *
744 * The latter sequence of calls is inferred to be able to throw
745 * the additional exception types {@link
746 * InvocationTargetException} and {@link
747 * NoSuchMethodException}. Both of these exception types are
748 * subclasses of {@link ReflectiveOperationException}.
749 *
750 * @return a newly allocated instance of the class represented by this
751 * object.
752 * @throws IllegalAccessException if the class or its nullary
753 * constructor is not accessible.
754 * @throws InstantiationException
755 * if this {@code Class} represents an abstract class,
756 * an interface, an array class, a primitive type, or void;
757 * or if the class has no nullary constructor;
758 * or if the instantiation fails for some other reason.
759 * @throws ExceptionInInitializerError if the initialization
760 * provoked by this method fails.
761 */
762 @CallerSensitive
763 @Deprecated(since="9")
764 public T newInstance()
765 throws InstantiationException, IllegalAccessException
766 {
767 // Constructor lookup
768 Constructor<T> tmpConstructor = cachedConstructor;
769 if (tmpConstructor == null) {
770 if (this == Class.class) {
771 throw new IllegalAccessException(
772 "Can not call newInstance() on the Class for java.lang.Class"
773 );
774 }
775 try {
776 Class<?>[] empty = {};
777 final Constructor<T> c = getReflectionFactory().copyConstructor(
778 getConstructor0(empty, Member.DECLARED));
779 // Disable accessibility checks on the constructor
780 // access check is done with the true caller
781 c.setAccessible(true);
782 cachedConstructor = tmpConstructor = c;
783 } catch (NoSuchMethodException e) {
784 throw (InstantiationException)
785 new InstantiationException(getName()).initCause(e);
786 }
787 }
788
789 try {
790 Class<?> caller = Reflection.getCallerClass();
791 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
792 } catch (InvocationTargetException e) {
793 Unsafe.getUnsafe().throwException(e.getTargetException());
794 // Not reached
795 return null;
796 }
797 }
798
799 private transient volatile Constructor<T> cachedConstructor;
800
801 /**
802 * Determines if the specified {@code Object} is assignment-compatible
803 * with the object represented by this {@code Class}. This method is
804 * the dynamic equivalent of the Java language {@code instanceof}
805 * operator. The method returns {@code true} if the specified
806 * {@code Object} argument is non-null and can be cast to the
807 * reference type represented by this {@code Class} object without
808 * raising a {@code ClassCastException.} It returns {@code false}
809 * otherwise.
810 *
811 * <p> Specifically, if this {@code Class} object represents a
812 * declared class, this method returns {@code true} if the specified
813 * {@code Object} argument is an instance of the represented class (or
814 * of any of its subclasses); it returns {@code false} otherwise. If
815 * this {@code Class} object represents an array class, this method
816 * returns {@code true} if the specified {@code Object} argument
817 * can be converted to an object of the array class by an identity
818 * conversion or by a widening reference conversion; it returns
819 * {@code false} otherwise. If this {@code Class} object
820 * represents an interface, this method returns {@code true} if the
821 * class or any superclass of the specified {@code Object} argument
822 * implements this interface; it returns {@code false} otherwise. If
823 * this {@code Class} object represents a primitive type, this method
824 * returns {@code false}.
825 *
826 * @param obj the object to check
827 * @return true if {@code obj} is an instance of this class
828 *
829 * @since 1.1
830 */
831 @IntrinsicCandidate
832 public native boolean isInstance(Object obj);
833
834
835 /**
836 * Determines if the class or interface represented by this
837 * {@code Class} object is either the same as, or is a superclass or
838 * superinterface of, the class or interface represented by the specified
839 * {@code Class} parameter. It returns {@code true} if so;
840 * otherwise it returns {@code false}. If this {@code Class}
841 * object represents a primitive type, this method returns
842 * {@code true} if the specified {@code Class} parameter is
843 * exactly this {@code Class} object; otherwise it returns
844 * {@code false}.
845 *
846 * <p> Specifically, this method tests whether the type represented by the
847 * specified {@code Class} parameter can be converted to the type
848 * represented by this {@code Class} object via an identity conversion
849 * or via a widening reference conversion. See <cite>The Java Language
850 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
851 * for details.
852 *
853 * @param cls the {@code Class} object to be checked
854 * @return the {@code boolean} value indicating whether objects of the
855 * type {@code cls} can be assigned to objects of this class
856 * @throws NullPointerException if the specified Class parameter is
857 * null.
858 * @since 1.1
859 */
860 @IntrinsicCandidate
861 public native boolean isAssignableFrom(Class<?> cls);
862
863
864 /**
865 * Determines if this {@code Class} object represents an
866 * interface type.
867 *
868 * @return {@code true} if this {@code Class} object represents an interface;
869 * {@code false} otherwise.
870 */
871 public boolean isInterface() {
872 return Modifier.isInterface(modifiers);
873 }
874
875
876 /**
877 * Determines if this {@code Class} object represents an array class.
878 *
879 * @return {@code true} if this {@code Class} object represents an array class;
880 * {@code false} otherwise.
881 * @since 1.1
882 */
883 public boolean isArray() {
884 return componentType != null;
885 }
886
887
888 /**
889 * Determines if this {@code Class} object represents a primitive
890 * type or void.
891 *
892 * <p> There are nine predefined {@code Class} objects to
893 * represent the eight primitive types and void. These are
894 * created by the Java Virtual Machine, and have the same
895 * {@linkplain #getName() names} as the primitive types that they
896 * represent, namely {@code boolean}, {@code byte}, {@code char},
897 * {@code short}, {@code int}, {@code long}, {@code float}, and
898 * {@code double}.
899 *
900 * <p>No other class objects are considered primitive.
901 *
902 * @apiNote
903 * A {@code Class} object represented by a primitive type can be
904 * accessed via the {@code TYPE} public static final variables
905 * defined in the primitive wrapper classes such as {@link
906 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
907 * language, the objects may be referred to by a class literal
908 * expression such as {@code int.class}. The {@code Class} object
909 * for void can be expressed as {@code void.class} or {@link
910 * java.lang.Void#TYPE Void.TYPE}.
911 *
912 * @return true if and only if this class represents a primitive type
913 *
914 * @see java.lang.Boolean#TYPE
915 * @see java.lang.Character#TYPE
916 * @see java.lang.Byte#TYPE
917 * @see java.lang.Short#TYPE
918 * @see java.lang.Integer#TYPE
919 * @see java.lang.Long#TYPE
920 * @see java.lang.Float#TYPE
921 * @see java.lang.Double#TYPE
922 * @see java.lang.Void#TYPE
923 * @since 1.1
924 * @jls 15.8.2 Class Literals
925 */
926 public boolean isPrimitive() {
927 return primitive;
928 }
929
930 /**
931 * Returns true if this {@code Class} object represents an annotation
932 * interface. Note that if this method returns true, {@link #isInterface()}
933 * would also return true, as all annotation interfaces are also interfaces.
934 *
935 * @return {@code true} if this {@code Class} object represents an annotation
936 * interface; {@code false} otherwise
937 * @since 1.5
938 */
939 public boolean isAnnotation() {
940 return (getModifiers() & ANNOTATION) != 0;
941 }
942
943 /**
944 *{@return {@code true} if and only if this class has the synthetic modifier
945 * bit set}
946 *
947 * @jls 13.1 The Form of a Binary
948 * @jvms 4.1 The {@code ClassFile} Structure
949 * @see <a
950 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
951 * programming language and JVM modeling in core reflection</a>
952 * @since 1.5
953 */
954 public boolean isSynthetic() {
955 return (getModifiers() & SYNTHETIC) != 0;
956 }
957
958 /**
959 * Returns the name of the entity (class, interface, array class,
960 * primitive type, or void) represented by this {@code Class} object.
961 *
962 * <p> If this {@code Class} object represents a class or interface,
963 * not an array class, then:
964 * <ul>
965 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
966 * then the {@linkplain ClassLoader##binary-name binary name}
967 * of the class or interface is returned.
968 * <li> If the class or interface is hidden, then the result is a string
969 * of the form: {@code N + '/' + <suffix>}
970 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
971 * indicated by the {@code class} file passed to
972 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
973 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
974 * </ul>
975 *
976 * <p> If this {@code Class} object represents an array class, then
977 * the result is a string consisting of one or more '{@code [}' characters
978 * representing the depth of the array nesting, followed by the element
979 * type as encoded using the following table:
980 *
981 * <blockquote><table class="striped" id="nameFormat">
982 * <caption style="display:none">Element types and encodings</caption>
983 * <thead>
984 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
985 * </thead>
986 * <tbody style="text-align:left">
987 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
988 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
989 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
990 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
991 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
992 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
993 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
994 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
995 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
996 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
997 * </tbody>
998 * </table></blockquote>
999 *
1000 * <p> If this {@code Class} object represents a primitive type or {@code void},
1001 * then the result is a string with the same spelling as the Java language
1002 * keyword which corresponds to the primitive type or {@code void}.
1003 *
1004 * <p> Examples:
1005 * <blockquote><pre>
1006 * String.class.getName()
1007 * returns "java.lang.String"
1008 * Character.UnicodeBlock.class.getName()
1009 * returns "java.lang.Character$UnicodeBlock"
1010 * byte.class.getName()
1011 * returns "byte"
1012 * (new Object[3]).getClass().getName()
1013 * returns "[Ljava.lang.Object;"
1014 * (new int[3][4][5][6][7][8][9]).getClass().getName()
1015 * returns "[[[[[[[I"
1016 * </pre></blockquote>
1017 *
1018 * @apiNote
1019 * Distinct class objects can have the same name but different class loaders.
1020 *
1021 * @return the name of the class, interface, or other entity
1022 * represented by this {@code Class} object.
1023 * @jls 13.1 The Form of a Binary
1024 */
1025 public String getName() {
1026 String name = this.name;
1027 return name != null ? name : initClassName();
1028 }
1029
1030 // Cache the name to reduce the number of calls into the VM.
1031 // This field would be set by VM itself during initClassName call.
1032 private transient String name;
1033 private native String initClassName();
1034
1035 /**
1036 * Returns the class loader for the class. Some implementations may use
1037 * null to represent the bootstrap class loader. This method will return
1038 * null in such implementations if this class was loaded by the bootstrap
1039 * class loader.
1040 *
1041 * <p>If this {@code Class} object
1042 * represents a primitive type or void, null is returned.
1043 *
1044 * @return the class loader that loaded the class or interface
1045 * represented by this {@code Class} object.
1046 * @see java.lang.ClassLoader
1047 */
1048 public ClassLoader getClassLoader() {
1049 return classLoader;
1050 }
1051
1052 // Package-private to allow ClassLoader access
1053 ClassLoader getClassLoader0() { return classLoader; }
1054
1055 /**
1056 * Returns the module that this class or interface is a member of.
1057 *
1058 * If this class represents an array type then this method returns the
1059 * {@code Module} for the element type. If this class represents a
1060 * primitive type or void, then the {@code Module} object for the
1061 * {@code java.base} module is returned.
1062 *
1063 * If this class is in an unnamed module then the {@linkplain
1064 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1065 * loader for this class is returned.
1066 *
1067 * @return the module that this class or interface is a member of
1068 *
1069 * @since 9
1070 */
1071 public Module getModule() {
1072 return module;
1073 }
1074
1075 // set by VM
1076 @Stable
1077 private transient Module module;
1078
1079 // Initialized in JVM not by private constructor
1080 // This field is filtered from reflection access, i.e. getDeclaredField
1081 // will throw NoSuchFieldException
1082 private final ClassLoader classLoader;
1083
1084 private transient Object classData; // Set by VM
1085 private transient Object[] signers; // Read by VM, mutable
1086 private final transient char modifiers; // Set by the VM
1087 private final transient char classFileAccessFlags; // Set by the VM
1088 private final transient boolean primitive; // Set by the VM if the Class is a primitive type.
1089
1090 // package-private
1091 Object getClassData() {
1092 return classData;
1093 }
1094
1095 /**
1096 * Returns an array of {@code TypeVariable} objects that represent the
1097 * type variables declared by the generic declaration represented by this
1098 * {@code GenericDeclaration} object, in declaration order. Returns an
1099 * array of length 0 if the underlying generic declaration declares no type
1100 * variables.
1101 *
1102 * @return an array of {@code TypeVariable} objects that represent
1103 * the type variables declared by this generic declaration
1104 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1105 * signature of this generic declaration does not conform to
1106 * the format specified in section {@jvms 4.7.9} of
1107 * <cite>The Java Virtual Machine Specification</cite>
1108 * @since 1.5
1109 */
1110 @SuppressWarnings("unchecked")
1111 public TypeVariable<Class<T>>[] getTypeParameters() {
1112 ClassRepository info = getGenericInfo();
1113 if (info != null)
1114 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1115 else
1116 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1117 }
1118
1119
1120 /**
1121 * Returns the {@code Class} representing the direct superclass of the
1122 * entity (class, interface, primitive type or void) represented by
1123 * this {@code Class}. If this {@code Class} represents either the
1124 * {@code Object} class, an interface, a primitive type, or void, then
1125 * null is returned. If this {@code Class} object represents an array class
1126 * then the {@code Class} object representing the {@code Object} class is
1127 * returned.
1128 *
1129 * @return the direct superclass of the class represented by this {@code Class} object
1130 */
1131 @IntrinsicCandidate
1132 public native Class<? super T> getSuperclass();
1133
1134
1135 /**
1136 * Returns the {@code Type} representing the direct superclass of
1137 * the entity (class, interface, primitive type or void) represented by
1138 * this {@code Class} object.
1139 *
1140 * <p>If the superclass is a parameterized type, the {@code Type}
1141 * object returned must accurately reflect the actual type
1142 * arguments used in the source code. The parameterized type
1143 * representing the superclass is created if it had not been
1144 * created before. See the declaration of {@link
1145 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1146 * semantics of the creation process for parameterized types. If
1147 * this {@code Class} object represents either the {@code Object}
1148 * class, an interface, a primitive type, or void, then null is
1149 * returned. If this {@code Class} object represents an array class
1150 * then the {@code Class} object representing the {@code Object} class is
1151 * returned.
1152 *
1153 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1154 * class signature does not conform to the format specified in
1155 * section {@jvms 4.7.9} of <cite>The Java Virtual
1156 * Machine Specification</cite>
1157 * @throws TypeNotPresentException if the generic superclass
1158 * refers to a non-existent type declaration
1159 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1160 * generic superclass refers to a parameterized type that cannot be
1161 * instantiated for any reason
1162 * @return the direct superclass of the class represented by this {@code Class} object
1163 * @since 1.5
1164 */
1165 public Type getGenericSuperclass() {
1166 ClassRepository info = getGenericInfo();
1167 if (info == null) {
1168 return getSuperclass();
1169 }
1170
1171 // Historical irregularity:
1172 // Generic signature marks interfaces with superclass = Object
1173 // but this API returns null for interfaces
1174 if (isInterface()) {
1175 return null;
1176 }
1177
1178 return info.getSuperclass();
1179 }
1180
1181 /**
1182 * Gets the package of this class.
1183 *
1184 * <p>If this class represents an array type, a primitive type or void,
1185 * this method returns {@code null}.
1186 *
1187 * @return the package of this class.
1188 */
1189 public Package getPackage() {
1190 if (isPrimitive() || isArray()) {
1191 return null;
1192 }
1193 ClassLoader cl = classLoader;
1194 return cl != null ? cl.definePackage(this)
1195 : BootLoader.definePackage(this);
1196 }
1197
1198 /**
1199 * Returns the fully qualified package name.
1200 *
1201 * <p> If this class is a top level class, then this method returns the fully
1202 * qualified name of the package that the class is a member of, or the
1203 * empty string if the class is in an unnamed package.
1204 *
1205 * <p> If this class is a member class, then this method is equivalent to
1206 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1207 * enclosing class}.
1208 *
1209 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1210 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1211 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1212 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1213 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1214 *
1215 * <p> If this class represents an array type then this method returns the
1216 * package name of the element type. If this class represents a primitive
1217 * type or void then the package name "{@code java.lang}" is returned.
1218 *
1219 * @return the fully qualified package name
1220 *
1221 * @since 9
1222 * @jls 6.7 Fully Qualified Names and Canonical Names
1223 */
1224 public String getPackageName() {
1225 String pn = this.packageName;
1226 if (pn == null) {
1227 Class<?> c = isArray() ? elementType() : this;
1228 if (c.isPrimitive()) {
1229 pn = "java.lang";
1230 } else {
1231 String cn = c.getName();
1232 int dot = cn.lastIndexOf('.');
1233 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1234 }
1235 this.packageName = pn;
1236 }
1237 return pn;
1238 }
1239
1240 // cached package name
1241 private transient String packageName;
1242
1243 /**
1244 * Returns the interfaces directly implemented by the class or interface
1245 * represented by this {@code Class} object.
1246 *
1247 * <p>If this {@code Class} object represents a class, the return value is an array
1248 * containing objects representing all interfaces directly implemented by
1249 * the class. The order of the interface objects in the array corresponds
1250 * to the order of the interface names in the {@code implements} clause of
1251 * the declaration of the class represented by this {@code Class} object. For example,
1252 * given the declaration:
1253 * <blockquote>
1254 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1255 * </blockquote>
1256 * suppose the value of {@code s} is an instance of
1257 * {@code Shimmer}; the value of the expression:
1258 * <blockquote>
1259 * {@code s.getClass().getInterfaces()[0]}
1260 * </blockquote>
1261 * is the {@code Class} object that represents interface
1262 * {@code FloorWax}; and the value of:
1263 * <blockquote>
1264 * {@code s.getClass().getInterfaces()[1]}
1265 * </blockquote>
1266 * is the {@code Class} object that represents interface
1267 * {@code DessertTopping}.
1268 *
1269 * <p>If this {@code Class} object represents an interface, the array contains objects
1270 * representing all interfaces directly extended by the interface. The
1271 * order of the interface objects in the array corresponds to the order of
1272 * the interface names in the {@code extends} clause of the declaration of
1273 * the interface represented by this {@code Class} object.
1274 *
1275 * <p>If this {@code Class} object represents a class or interface that implements no
1276 * interfaces, the method returns an array of length 0.
1277 *
1278 * <p>If this {@code Class} object represents a primitive type or void, the method
1279 * returns an array of length 0.
1280 *
1281 * <p>If this {@code Class} object represents an array type, the
1282 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1283 * returned in that order.
1284 *
1285 * @return an array of interfaces directly implemented by this class
1286 */
1287 public Class<?>[] getInterfaces() {
1288 // defensively copy before handing over to user code
1289 return getInterfaces(true);
1290 }
1291
1292 private Class<?>[] getInterfaces(boolean cloneArray) {
1293 ReflectionData<T> rd = reflectionData();
1294 Class<?>[] interfaces = rd.interfaces;
1295 if (interfaces == null) {
1296 interfaces = getInterfaces0();
1297 rd.interfaces = interfaces;
1298 }
1299 // defensively copy if requested
1300 return cloneArray ? interfaces.clone() : interfaces;
1301 }
1302
1303 private native Class<?>[] getInterfaces0();
1304
1305 /**
1306 * Returns the {@code Type}s representing the interfaces
1307 * directly implemented by the class or interface represented by
1308 * this {@code Class} object.
1309 *
1310 * <p>If a superinterface is a parameterized type, the
1311 * {@code Type} object returned for it must accurately reflect
1312 * the actual type arguments used in the source code. The
1313 * parameterized type representing each superinterface is created
1314 * if it had not been created before. See the declaration of
1315 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1316 * for the semantics of the creation process for parameterized
1317 * types.
1318 *
1319 * <p>If this {@code Class} object represents a class, the return value is an array
1320 * containing objects representing all interfaces directly implemented by
1321 * the class. The order of the interface objects in the array corresponds
1322 * to the order of the interface names in the {@code implements} clause of
1323 * the declaration of the class represented by this {@code Class} object.
1324 *
1325 * <p>If this {@code Class} object represents an interface, the array contains objects
1326 * representing all interfaces directly extended by the interface. The
1327 * order of the interface objects in the array corresponds to the order of
1328 * the interface names in the {@code extends} clause of the declaration of
1329 * the interface represented by this {@code Class} object.
1330 *
1331 * <p>If this {@code Class} object represents a class or interface that implements no
1332 * interfaces, the method returns an array of length 0.
1333 *
1334 * <p>If this {@code Class} object represents a primitive type or void, the method
1335 * returns an array of length 0.
1336 *
1337 * <p>If this {@code Class} object represents an array type, the
1338 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1339 * returned in that order.
1340 *
1341 * @throws java.lang.reflect.GenericSignatureFormatError
1342 * if the generic class signature does not conform to the
1343 * format specified in section {@jvms 4.7.9} of <cite>The
1344 * Java Virtual Machine Specification</cite>
1345 * @throws TypeNotPresentException if any of the generic
1346 * superinterfaces refers to a non-existent type declaration
1347 * @throws java.lang.reflect.MalformedParameterizedTypeException
1348 * if any of the generic superinterfaces refer to a parameterized
1349 * type that cannot be instantiated for any reason
1350 * @return an array of interfaces directly implemented by this class
1351 * @since 1.5
1352 */
1353 public Type[] getGenericInterfaces() {
1354 ClassRepository info = getGenericInfo();
1355 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1356 }
1357
1358
1359 /**
1360 * Returns the {@code Class} representing the component type of an
1361 * array. If this class does not represent an array class this method
1362 * returns null.
1363 *
1364 * @return the {@code Class} representing the component type of this
1365 * class if this class is an array
1366 * @see java.lang.reflect.Array
1367 * @since 1.1
1368 */
1369 public Class<?> getComponentType() {
1370 return componentType;
1371 }
1372
1373 // The componentType field's null value is the sole indication that the class
1374 // is an array - see isArray().
1375 private transient final Class<?> componentType;
1376
1377 /*
1378 * Returns the {@code Class} representing the element type of an array class.
1379 * If this class does not represent an array class, then this method returns
1380 * {@code null}.
1381 */
1382 private Class<?> elementType() {
1383 if (!isArray()) return null;
1384
1385 Class<?> c = this;
1386 while (c.isArray()) {
1387 c = c.getComponentType();
1388 }
1389 return c;
1390 }
1391
1392 /**
1393 * Returns the Java language modifiers for this class or interface, encoded
1394 * in an integer. The modifiers consist of the Java Virtual Machine's
1395 * constants for {@code public}, {@code protected},
1396 * {@code private}, {@code final}, {@code static},
1397 * {@code abstract} and {@code interface}; they should be decoded
1398 * using the methods of class {@code Modifier}.
1399 *
1400 * <p> If the underlying class is an array class:
1401 * <ul>
1402 * <li> its {@code public}, {@code private} and {@code protected}
1403 * modifiers are the same as those of its component type
1404 * <li> its {@code abstract} and {@code final} modifiers are always
1405 * {@code true}
1406 * <li> its interface modifier is always {@code false}, even when
1407 * the component type is an interface
1408 * <li> its {@code identity} modifier is always true
1409 * </ul>
1410 * If this {@code Class} object represents a primitive type or
1411 * void, its {@code public}, {@code abstract}, and {@code final}
1412 * modifiers are always {@code true}.
1413 * For {@code Class} objects representing void, primitive types, and
1414 * arrays, the values of other modifiers are {@code false} other
1415 * than as specified above.
1416 *
1417 * <p> The modifier encodings are defined in section {@jvms 4.1}
1418 * of <cite>The Java Virtual Machine Specification</cite>.
1419 *
1420 * @return the {@code int} representing the modifiers for this class
1421 * @see java.lang.reflect.Modifier
1422 * @see #accessFlags()
1423 * @see <a
1424 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1425 * programming language and JVM modeling in core reflection</a>
1426 * @since 1.1
1427 * @jls 8.1.1 Class Modifiers
1428 * @jls 9.1.1 Interface Modifiers
1429 * @jvms 4.1 The {@code ClassFile} Structure
1430 */
1431 public int getModifiers() { return modifiers; }
1432
1433 /**
1434 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1435 * flags} for this class, possibly empty}
1436 * The {@code AccessFlags} may depend on the class file format version of the class.
1437 *
1438 * <p> If the underlying class is an array class:
1439 * <ul>
1440 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1441 * access flags are the same as those of its component type
1442 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1443 * <li> its {@code INTERFACE} flag is absent, even when the
1444 * component type is an interface
1445 * <li> its {@code identity} modifier is always true
1446 * </ul>
1447 * If this {@code Class} object represents a primitive type or
1448 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1449 * {@code FINAL}.
1450 * For {@code Class} objects representing void, primitive types, and
1451 * arrays, access flags are absent other than as specified above.
1452 *
1453 * @see #getModifiers()
1454 * @jvms 4.1 The ClassFile Structure
1455 * @jvms 4.7.6 The InnerClasses Attribute
1456 * @since 20
1457 */
1458 public Set<AccessFlag> accessFlags() {
1459 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1460 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1461 // and STATIC, which are not allowed on Location.CLASS.
1462 // Use getClassFileAccessFlags to expose SUPER status.
1463 // Arrays need to use PRIVATE/PROTECTED from its component modifiers.
1464 var location = (isMemberClass() || isLocalClass() ||
1465 isAnonymousClass() || isArray()) ?
1466 AccessFlag.Location.INNER_CLASS :
1467 AccessFlag.Location.CLASS;
1468 int accessFlags = location == AccessFlag.Location.CLASS ? getClassFileAccessFlags() : getModifiers();
1469 var reflectionFactory = getReflectionFactory();
1470 var ans = reflectionFactory.parseAccessFlags(accessFlags, location, this);
1471 if (PreviewFeatures.isEnabled() && reflectionFactory.classFileFormatVersion(this) != ClassFileFormatVersion.CURRENT_PREVIEW_FEATURES
1472 && isIdentity()) {
1473 var set = new HashSet<>(ans);
1474 set.add(AccessFlag.IDENTITY);
1475 return Set.copyOf(set);
1476 }
1477 return ans;
1478 }
1479
1480 /**
1481 * Gets the signers of this class.
1482 *
1483 * @return the signers of this class, or null if there are no signers. In
1484 * particular, this method returns null if this {@code Class} object represents
1485 * a primitive type or void.
1486 * @since 1.1
1487 */
1488
1489 public Object[] getSigners() {
1490 var signers = this.signers;
1491 return signers == null ? null : signers.clone();
1492 }
1493
1494 /**
1495 * Set the signers of this class.
1496 */
1497 void setSigners(Object[] signers) {
1498 if (!isPrimitive() && !isArray()) {
1499 this.signers = signers;
1500 }
1501 }
1502
1503 /**
1504 * If this {@code Class} object represents a local or anonymous
1505 * class within a method, returns a {@link
1506 * java.lang.reflect.Method Method} object representing the
1507 * immediately enclosing method of the underlying class. Returns
1508 * {@code null} otherwise.
1509 *
1510 * In particular, this method returns {@code null} if the underlying
1511 * class is a local or anonymous class immediately enclosed by a class or
1512 * interface declaration, instance initializer or static initializer.
1513 *
1514 * @return the immediately enclosing method of the underlying class, if
1515 * that class is a local or anonymous class; otherwise {@code null}.
1516 *
1517 * @since 1.5
1518 */
1519 public Method getEnclosingMethod() {
1520 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1521
1522 if (enclosingInfo == null)
1523 return null;
1524 else {
1525 if (!enclosingInfo.isMethod())
1526 return null;
1527
1528 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1529 getFactory());
1530 Class<?> returnType = toClass(typeInfo.getReturnType());
1531 Type [] parameterTypes = typeInfo.getParameterTypes();
1532 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1533
1534 // Convert Types to Classes; returned types *should*
1535 // be class objects since the methodDescriptor's used
1536 // don't have generics information
1537 for(int i = 0; i < parameterClasses.length; i++)
1538 parameterClasses[i] = toClass(parameterTypes[i]);
1539
1540 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1541 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1542
1543 /*
1544 * Loop over all declared methods; match method name,
1545 * number of and type of parameters, *and* return
1546 * type. Matching return type is also necessary
1547 * because of covariant returns, etc.
1548 */
1549 ReflectionFactory fact = getReflectionFactory();
1550 for (Method m : candidates) {
1551 if (m.getName().equals(enclosingInfo.getName()) &&
1552 arrayContentsEq(parameterClasses,
1553 fact.getExecutableSharedParameterTypes(m))) {
1554 // finally, check return type
1555 if (m.getReturnType().equals(returnType)) {
1556 return fact.copyMethod(m);
1557 }
1558 }
1559 }
1560
1561 throw new InternalError("Enclosing method not found");
1562 }
1563 }
1564
1565 private native Object[] getEnclosingMethod0();
1566
1567 private EnclosingMethodInfo getEnclosingMethodInfo() {
1568 Object[] enclosingInfo = getEnclosingMethod0();
1569 if (enclosingInfo == null)
1570 return null;
1571 else {
1572 return new EnclosingMethodInfo(enclosingInfo);
1573 }
1574 }
1575
1576 private static final class EnclosingMethodInfo {
1577 private final Class<?> enclosingClass;
1578 private final String name;
1579 private final String descriptor;
1580
1581 static void validate(Object[] enclosingInfo) {
1582 if (enclosingInfo.length != 3)
1583 throw new InternalError("Malformed enclosing method information");
1584 try {
1585 // The array is expected to have three elements:
1586
1587 // the immediately enclosing class
1588 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1589 assert(enclosingClass != null);
1590
1591 // the immediately enclosing method or constructor's
1592 // name (can be null).
1593 String name = (String)enclosingInfo[1];
1594
1595 // the immediately enclosing method or constructor's
1596 // descriptor (null iff name is).
1597 String descriptor = (String)enclosingInfo[2];
1598 assert((name != null && descriptor != null) || name == descriptor);
1599 } catch (ClassCastException cce) {
1600 throw new InternalError("Invalid type in enclosing method information", cce);
1601 }
1602 }
1603
1604 EnclosingMethodInfo(Object[] enclosingInfo) {
1605 validate(enclosingInfo);
1606 this.enclosingClass = (Class<?>)enclosingInfo[0];
1607 this.name = (String)enclosingInfo[1];
1608 this.descriptor = (String)enclosingInfo[2];
1609 }
1610
1611 boolean isPartial() {
1612 return enclosingClass == null || name == null || descriptor == null;
1613 }
1614
1615 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1616
1617 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1618
1619 Class<?> getEnclosingClass() { return enclosingClass; }
1620
1621 String getName() { return name; }
1622
1623 String getDescriptor() { return descriptor; }
1624
1625 }
1626
1627 private static Class<?> toClass(Type o) {
1628 if (o instanceof GenericArrayType gat)
1629 return toClass(gat.getGenericComponentType()).arrayType();
1630 return (Class<?>)o;
1631 }
1632
1633 /**
1634 * If this {@code Class} object represents a local or anonymous
1635 * class within a constructor, returns a {@link
1636 * java.lang.reflect.Constructor Constructor} object representing
1637 * the immediately enclosing constructor of the underlying
1638 * class. Returns {@code null} otherwise. In particular, this
1639 * method returns {@code null} if the underlying class is a local
1640 * or anonymous class immediately enclosed by a class or
1641 * interface declaration, instance initializer or static initializer.
1642 *
1643 * @return the immediately enclosing constructor of the underlying class, if
1644 * that class is a local or anonymous class; otherwise {@code null}.
1645 *
1646 * @since 1.5
1647 */
1648 public Constructor<?> getEnclosingConstructor() {
1649 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1650
1651 if (enclosingInfo == null)
1652 return null;
1653 else {
1654 if (!enclosingInfo.isConstructor())
1655 return null;
1656
1657 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1658 getFactory());
1659 Type [] parameterTypes = typeInfo.getParameterTypes();
1660 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1661
1662 // Convert Types to Classes; returned types *should*
1663 // be class objects since the methodDescriptor's used
1664 // don't have generics information
1665 for (int i = 0; i < parameterClasses.length; i++)
1666 parameterClasses[i] = toClass(parameterTypes[i]);
1667
1668
1669 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1670 Constructor<?>[] candidates = enclosingCandidate
1671 .privateGetDeclaredConstructors(false);
1672 /*
1673 * Loop over all declared constructors; match number
1674 * of and type of parameters.
1675 */
1676 ReflectionFactory fact = getReflectionFactory();
1677 for (Constructor<?> c : candidates) {
1678 if (arrayContentsEq(parameterClasses,
1679 fact.getExecutableSharedParameterTypes(c))) {
1680 return fact.copyConstructor(c);
1681 }
1682 }
1683
1684 throw new InternalError("Enclosing constructor not found");
1685 }
1686 }
1687
1688
1689 /**
1690 * If the class or interface represented by this {@code Class} object
1691 * is a member of another class, returns the {@code Class} object
1692 * representing the class in which it was declared. This method returns
1693 * null if this class or interface is not a member of any other class. If
1694 * this {@code Class} object represents an array class, a primitive
1695 * type, or void, then this method returns null.
1696 *
1697 * @return the declaring class for this class
1698 * @since 1.1
1699 */
1700 public Class<?> getDeclaringClass() {
1701 return getDeclaringClass0();
1702 }
1703
1704 private native Class<?> getDeclaringClass0();
1705
1706
1707 /**
1708 * Returns the immediately enclosing class of the underlying
1709 * class. If the underlying class is a top level class this
1710 * method returns {@code null}.
1711 * @return the immediately enclosing class of the underlying class
1712 * @since 1.5
1713 */
1714 public Class<?> getEnclosingClass() {
1715 // There are five kinds of classes (or interfaces):
1716 // a) Top level classes
1717 // b) Nested classes (static member classes)
1718 // c) Inner classes (non-static member classes)
1719 // d) Local classes (named classes declared within a method)
1720 // e) Anonymous classes
1721
1722
1723 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1724 // attribute if and only if it is a local class or an
1725 // anonymous class.
1726 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1727 Class<?> enclosingCandidate;
1728
1729 if (enclosingInfo == null) {
1730 // This is a top level or a nested class or an inner class (a, b, or c)
1731 enclosingCandidate = getDeclaringClass0();
1732 } else {
1733 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1734 // This is a local class or an anonymous class (d or e)
1735 if (enclosingClass == this || enclosingClass == null)
1736 throw new InternalError("Malformed enclosing method information");
1737 else
1738 enclosingCandidate = enclosingClass;
1739 }
1740 return enclosingCandidate;
1741 }
1742
1743 /**
1744 * Returns the simple name of the underlying class as given in the
1745 * source code. An empty string is returned if the underlying class is
1746 * {@linkplain #isAnonymousClass() anonymous}.
1747 * A {@linkplain #isSynthetic() synthetic class}, one not present
1748 * in source code, can have a non-empty name including special
1749 * characters, such as "{@code $}".
1750 *
1751 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1752 * component type with "[]" appended. In particular the simple
1753 * name of an array class whose component type is anonymous is "[]".
1754 *
1755 * @return the simple name of the underlying class
1756 * @since 1.5
1757 */
1758 public String getSimpleName() {
1759 ReflectionData<T> rd = reflectionData();
1760 String simpleName = rd.simpleName;
1761 if (simpleName == null) {
1762 rd.simpleName = simpleName = getSimpleName0();
1763 }
1764 return simpleName;
1765 }
1766
1767 private String getSimpleName0() {
1768 if (isArray()) {
1769 return getComponentType().getSimpleName().concat("[]");
1770 }
1771 String simpleName = getSimpleBinaryName();
1772 if (simpleName == null) { // top level class
1773 simpleName = getName();
1774 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1775 }
1776 return simpleName;
1777 }
1778
1779 /**
1780 * Return an informative string for the name of this class or interface.
1781 *
1782 * @return an informative string for the name of this class or interface
1783 * @since 1.8
1784 */
1785 public String getTypeName() {
1786 if (isArray()) {
1787 try {
1788 Class<?> cl = this;
1789 int dimensions = 0;
1790 do {
1791 dimensions++;
1792 cl = cl.getComponentType();
1793 } while (cl.isArray());
1794 return cl.getName().concat("[]".repeat(dimensions));
1795 } catch (Throwable e) { /*FALLTHRU*/ }
1796 }
1797 return getName();
1798 }
1799
1800 /**
1801 * Returns the canonical name of the underlying class as
1802 * defined by <cite>The Java Language Specification</cite>.
1803 * Returns {@code null} if the underlying class does not have a canonical
1804 * name. Classes without canonical names include:
1805 * <ul>
1806 * <li>a {@linkplain #isLocalClass() local class}
1807 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1808 * <li>a {@linkplain #isHidden() hidden class}
1809 * <li>an array whose component type does not have a canonical name</li>
1810 * </ul>
1811 *
1812 * The canonical name for a primitive class is the keyword for the
1813 * corresponding primitive type ({@code byte}, {@code short},
1814 * {@code char}, {@code int}, and so on).
1815 *
1816 * <p>An array type has a canonical name if and only if its
1817 * component type has a canonical name. When an array type has a
1818 * canonical name, it is equal to the canonical name of the
1819 * component type followed by "{@code []}".
1820 *
1821 * @return the canonical name of the underlying class if it exists, and
1822 * {@code null} otherwise.
1823 * @jls 6.7 Fully Qualified Names and Canonical Names
1824 * @since 1.5
1825 */
1826 public String getCanonicalName() {
1827 ReflectionData<T> rd = reflectionData();
1828 String canonicalName = rd.canonicalName;
1829 if (canonicalName == null) {
1830 rd.canonicalName = canonicalName = getCanonicalName0();
1831 }
1832 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1833 }
1834
1835 private String getCanonicalName0() {
1836 if (isArray()) {
1837 String canonicalName = getComponentType().getCanonicalName();
1838 if (canonicalName != null)
1839 return canonicalName.concat("[]");
1840 else
1841 return ReflectionData.NULL_SENTINEL;
1842 }
1843 if (isHidden() || isLocalOrAnonymousClass())
1844 return ReflectionData.NULL_SENTINEL;
1845 Class<?> enclosingClass = getEnclosingClass();
1846 if (enclosingClass == null) { // top level class
1847 return getName();
1848 } else {
1849 String enclosingName = enclosingClass.getCanonicalName();
1850 if (enclosingName == null)
1851 return ReflectionData.NULL_SENTINEL;
1852 String simpleName = getSimpleName();
1853 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1854 .append(enclosingName)
1855 .append('.')
1856 .append(simpleName)
1857 .toString();
1858 }
1859 }
1860
1861 /**
1862 * Returns {@code true} if and only if the underlying class
1863 * is an anonymous class.
1864 *
1865 * @apiNote
1866 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1867 *
1868 * @return {@code true} if and only if this class is an anonymous class.
1869 * @since 1.5
1870 * @jls 15.9.5 Anonymous Class Declarations
1871 */
1872 public boolean isAnonymousClass() {
1873 return !isArray() && isLocalOrAnonymousClass() &&
1874 getSimpleBinaryName0() == null;
1875 }
1876
1877 /**
1878 * Returns {@code true} if and only if the underlying class
1879 * is a local class.
1880 *
1881 * @return {@code true} if and only if this class is a local class.
1882 * @since 1.5
1883 * @jls 14.3 Local Class and Interface Declarations
1884 */
1885 public boolean isLocalClass() {
1886 return isLocalOrAnonymousClass() &&
1887 (isArray() || getSimpleBinaryName0() != null);
1888 }
1889
1890 /**
1891 * Returns {@code true} if and only if the underlying class
1892 * is a member class.
1893 *
1894 * @return {@code true} if and only if this class is a member class.
1895 * @since 1.5
1896 * @jls 8.5 Member Class and Interface Declarations
1897 */
1898 public boolean isMemberClass() {
1899 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1900 }
1901
1902 /**
1903 * Returns the "simple binary name" of the underlying class, i.e.,
1904 * the binary name without the leading enclosing class name.
1905 * Returns {@code null} if the underlying class is a top level
1906 * class.
1907 */
1908 private String getSimpleBinaryName() {
1909 if (isTopLevelClass())
1910 return null;
1911 String name = getSimpleBinaryName0();
1912 if (name == null) // anonymous class
1913 return "";
1914 return name;
1915 }
1916
1917 private native String getSimpleBinaryName0();
1918
1919 /**
1920 * Returns {@code true} if this is a top level class. Returns {@code false}
1921 * otherwise.
1922 */
1923 private boolean isTopLevelClass() {
1924 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1925 }
1926
1927 /**
1928 * Returns {@code true} if this is a local class or an anonymous
1929 * class. Returns {@code false} otherwise.
1930 */
1931 private boolean isLocalOrAnonymousClass() {
1932 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1933 // attribute if and only if it is a local class or an
1934 // anonymous class.
1935 return hasEnclosingMethodInfo();
1936 }
1937
1938 private boolean hasEnclosingMethodInfo() {
1939 Object[] enclosingInfo = getEnclosingMethod0();
1940 if (enclosingInfo != null) {
1941 EnclosingMethodInfo.validate(enclosingInfo);
1942 return true;
1943 }
1944 return false;
1945 }
1946
1947 /**
1948 * Returns an array containing {@code Class} objects representing all
1949 * the public classes and interfaces that are members of the class
1950 * represented by this {@code Class} object. This includes public
1951 * class and interface members inherited from superclasses and public class
1952 * and interface members declared by the class. This method returns an
1953 * array of length 0 if this {@code Class} object has no public member
1954 * classes or interfaces. This method also returns an array of length 0 if
1955 * this {@code Class} object represents a primitive type, an array
1956 * class, or void.
1957 *
1958 * @return the array of {@code Class} objects representing the public
1959 * members of this class
1960 * @since 1.1
1961 */
1962 public Class<?>[] getClasses() {
1963 List<Class<?>> list = new ArrayList<>();
1964 Class<?> currentClass = Class.this;
1965 while (currentClass != null) {
1966 for (Class<?> m : currentClass.getDeclaredClasses()) {
1967 if (Modifier.isPublic(m.getModifiers())) {
1968 list.add(m);
1969 }
1970 }
1971 currentClass = currentClass.getSuperclass();
1972 }
1973 return list.toArray(new Class<?>[0]);
1974 }
1975
1976
1977 /**
1978 * Returns an array containing {@code Field} objects reflecting all
1979 * the accessible public fields of the class or interface represented by
1980 * this {@code Class} object.
1981 *
1982 * <p> If this {@code Class} object represents a class or interface with
1983 * no accessible public fields, then this method returns an array of length
1984 * 0.
1985 *
1986 * <p> If this {@code Class} object represents a class, then this method
1987 * returns the public fields of the class and of all its superclasses and
1988 * superinterfaces.
1989 *
1990 * <p> If this {@code Class} object represents an interface, then this
1991 * method returns the fields of the interface and of all its
1992 * superinterfaces.
1993 *
1994 * <p> If this {@code Class} object represents an array type, a primitive
1995 * type, or void, then this method returns an array of length 0.
1996 *
1997 * <p> The elements in the returned array are not sorted and are not in any
1998 * particular order.
1999 *
2000 * @return the array of {@code Field} objects representing the
2001 * public fields
2002 *
2003 * @since 1.1
2004 * @jls 8.2 Class Members
2005 * @jls 8.3 Field Declarations
2006 */
2007 public Field[] getFields() {
2008 return copyFields(privateGetPublicFields());
2009 }
2010
2011
2012 /**
2013 * Returns an array containing {@code Method} objects reflecting all the
2014 * public methods of the class or interface represented by this {@code
2015 * Class} object, including those declared by the class or interface and
2016 * those inherited from superclasses and superinterfaces.
2017 *
2018 * <p> If this {@code Class} object represents an array type, then the
2019 * returned array has a {@code Method} object for each of the public
2020 * methods inherited by the array type from {@code Object}. It does not
2021 * contain a {@code Method} object for {@code clone()}.
2022 *
2023 * <p> If this {@code Class} object represents an interface then the
2024 * returned array does not contain any implicitly declared methods from
2025 * {@code Object}. Therefore, if no methods are explicitly declared in
2026 * this interface or any of its superinterfaces then the returned array
2027 * has length 0. (Note that a {@code Class} object which represents a class
2028 * always has public methods, inherited from {@code Object}.)
2029 *
2030 * <p> The returned array never contains methods with names {@value
2031 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2032 *
2033 * <p> The elements in the returned array are not sorted and are not in any
2034 * particular order.
2035 *
2036 * <p> Generally, the result is computed as with the following 4 step algorithm.
2037 * Let C be the class or interface represented by this {@code Class} object:
2038 * <ol>
2039 * <li> A union of methods is composed of:
2040 * <ol type="a">
2041 * <li> C's declared public instance and static methods as returned by
2042 * {@link #getDeclaredMethods()} and filtered to include only public
2043 * methods.</li>
2044 * <li> If C is a class other than {@code Object}, then include the result
2045 * of invoking this algorithm recursively on the superclass of C.</li>
2046 * <li> Include the results of invoking this algorithm recursively on all
2047 * direct superinterfaces of C, but include only instance methods.</li>
2048 * </ol></li>
2049 * <li> Union from step 1 is partitioned into subsets of methods with same
2050 * signature (name, parameter types) and return type.</li>
2051 * <li> Within each such subset only the most specific methods are selected.
2052 * Let method M be a method from a set of methods with same signature
2053 * and return type. M is most specific if there is no such method
2054 * N != M from the same set, such that N is more specific than M.
2055 * N is more specific than M if:
2056 * <ol type="a">
2057 * <li> N is declared by a class and M is declared by an interface; or</li>
2058 * <li> N and M are both declared by classes or both by interfaces and
2059 * N's declaring type is the same as or a subtype of M's declaring type
2060 * (clearly, if M's and N's declaring types are the same type, then
2061 * M and N are the same method).</li>
2062 * </ol></li>
2063 * <li> The result of this algorithm is the union of all selected methods from
2064 * step 3.</li>
2065 * </ol>
2066 *
2067 * @apiNote There may be more than one method with a particular name
2068 * and parameter types in a class because while the Java language forbids a
2069 * class to declare multiple methods with the same signature but different
2070 * return types, the Java virtual machine does not. This
2071 * increased flexibility in the virtual machine can be used to
2072 * implement various language features. For example, covariant
2073 * returns can be implemented with {@linkplain
2074 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2075 * method and the overriding method would have the same
2076 * signature but different return types.
2077 *
2078 * @return the array of {@code Method} objects representing the
2079 * public methods of this class
2080 *
2081 * @jls 8.2 Class Members
2082 * @jls 8.4 Method Declarations
2083 * @since 1.1
2084 */
2085 public Method[] getMethods() {
2086 return copyMethods(privateGetPublicMethods());
2087 }
2088
2089
2090 /**
2091 * Returns an array containing {@code Constructor} objects reflecting
2092 * all the public constructors of the class represented by this
2093 * {@code Class} object. An array of length 0 is returned if the
2094 * class has no public constructors, or if the class is an array class, or
2095 * if the class reflects a primitive type or void.
2096 *
2097 * @apiNote
2098 * While this method returns an array of {@code
2099 * Constructor<T>} objects (that is an array of constructors from
2100 * this class), the return type of this method is {@code
2101 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2102 * might be expected. This less informative return type is
2103 * necessary since after being returned from this method, the
2104 * array could be modified to hold {@code Constructor} objects for
2105 * different classes, which would violate the type guarantees of
2106 * {@code Constructor<T>[]}.
2107 *
2108 * @return the array of {@code Constructor} objects representing the
2109 * public constructors of this class
2110 *
2111 * @see #getDeclaredConstructors()
2112 * @since 1.1
2113 */
2114 public Constructor<?>[] getConstructors() {
2115 return copyConstructors(privateGetDeclaredConstructors(true));
2116 }
2117
2118
2119 /**
2120 * Returns a {@code Field} object that reflects the specified public member
2121 * field of the class or interface represented by this {@code Class}
2122 * object. The {@code name} parameter is a {@code String} specifying the
2123 * simple name of the desired field.
2124 *
2125 * <p> The field to be reflected is determined by the algorithm that
2126 * follows. Let C be the class or interface represented by this {@code Class} object:
2127 *
2128 * <OL>
2129 * <LI> If C declares a public field with the name specified, that is the
2130 * field to be reflected.</LI>
2131 * <LI> If no field was found in step 1 above, this algorithm is applied
2132 * recursively to each direct superinterface of C. The direct
2133 * superinterfaces are searched in the order they were declared.</LI>
2134 * <LI> If no field was found in steps 1 and 2 above, and C has a
2135 * superclass S, then this algorithm is invoked recursively upon S.
2136 * If C has no superclass, then a {@code NoSuchFieldException}
2137 * is thrown.</LI>
2138 * </OL>
2139 *
2140 * <p> If this {@code Class} object represents an array type, then this
2141 * method does not find the {@code length} field of the array type.
2142 *
2143 * @param name the field name
2144 * @return the {@code Field} object of this class specified by
2145 * {@code name}
2146 * @throws NoSuchFieldException if a field with the specified name is
2147 * not found.
2148 * @throws NullPointerException if {@code name} is {@code null}
2149 *
2150 * @since 1.1
2151 * @jls 8.2 Class Members
2152 * @jls 8.3 Field Declarations
2153 */
2154 public Field getField(String name) throws NoSuchFieldException {
2155 Objects.requireNonNull(name);
2156 Field field = getField0(name);
2157 if (field == null) {
2158 throw new NoSuchFieldException(name);
2159 }
2160 return getReflectionFactory().copyField(field);
2161 }
2162
2163
2164 /**
2165 * Returns a {@code Method} object that reflects the specified public
2166 * member method of the class or interface represented by this
2167 * {@code Class} object. The {@code name} parameter is a
2168 * {@code String} specifying the simple name of the desired method. The
2169 * {@code parameterTypes} parameter is an array of {@code Class}
2170 * objects that identify the method's formal parameter types, in declared
2171 * order. If {@code parameterTypes} is {@code null}, it is
2172 * treated as if it were an empty array.
2173 *
2174 * <p> If this {@code Class} object represents an array type, then this
2175 * method finds any public method inherited by the array type from
2176 * {@code Object} except method {@code clone()}.
2177 *
2178 * <p> If this {@code Class} object represents an interface then this
2179 * method does not find any implicitly declared method from
2180 * {@code Object}. Therefore, if no methods are explicitly declared in
2181 * this interface or any of its superinterfaces, then this method does not
2182 * find any method.
2183 *
2184 * <p> This method does not find any method with name {@value
2185 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2186 *
2187 * <p> Generally, the method to be reflected is determined by the 4 step
2188 * algorithm that follows.
2189 * Let C be the class or interface represented by this {@code Class} object:
2190 * <ol>
2191 * <li> A union of methods is composed of:
2192 * <ol type="a">
2193 * <li> C's declared public instance and static methods as returned by
2194 * {@link #getDeclaredMethods()} and filtered to include only public
2195 * methods that match given {@code name} and {@code parameterTypes}</li>
2196 * <li> If C is a class other than {@code Object}, then include the result
2197 * of invoking this algorithm recursively on the superclass of C.</li>
2198 * <li> Include the results of invoking this algorithm recursively on all
2199 * direct superinterfaces of C, but include only instance methods.</li>
2200 * </ol></li>
2201 * <li> This union is partitioned into subsets of methods with same
2202 * return type (the selection of methods from step 1 also guarantees that
2203 * they have the same method name and parameter types).</li>
2204 * <li> Within each such subset only the most specific methods are selected.
2205 * Let method M be a method from a set of methods with same VM
2206 * signature (return type, name, parameter types).
2207 * M is most specific if there is no such method N != M from the same
2208 * set, such that N is more specific than M. N is more specific than M
2209 * if:
2210 * <ol type="a">
2211 * <li> N is declared by a class and M is declared by an interface; or</li>
2212 * <li> N and M are both declared by classes or both by interfaces and
2213 * N's declaring type is the same as or a subtype of M's declaring type
2214 * (clearly, if M's and N's declaring types are the same type, then
2215 * M and N are the same method).</li>
2216 * </ol></li>
2217 * <li> The result of this algorithm is chosen arbitrarily from the methods
2218 * with most specific return type among all selected methods from step 3.
2219 * Let R be a return type of a method M from the set of all selected methods
2220 * from step 3. M is a method with most specific return type if there is
2221 * no such method N != M from the same set, having return type S != R,
2222 * such that S is a subtype of R as determined by
2223 * R.class.{@link #isAssignableFrom}(S.class).
2224 * </ol>
2225 *
2226 * @apiNote There may be more than one method with matching name and
2227 * parameter types in a class because while the Java language forbids a
2228 * class to declare multiple methods with the same signature but different
2229 * return types, the Java virtual machine does not. This
2230 * increased flexibility in the virtual machine can be used to
2231 * implement various language features. For example, covariant
2232 * returns can be implemented with {@linkplain
2233 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2234 * method and the overriding method would have the same
2235 * signature but different return types. This method would return the
2236 * overriding method as it would have a more specific return type.
2237 *
2238 * @param name the name of the method
2239 * @param parameterTypes the list of parameters
2240 * @return the {@code Method} object that matches the specified
2241 * {@code name} and {@code parameterTypes}
2242 * @throws NoSuchMethodException if a matching method is not found
2243 * or if the name is {@value ConstantDescs#INIT_NAME} or
2244 * {@value ConstantDescs#CLASS_INIT_NAME}.
2245 * @throws NullPointerException if {@code name} is {@code null}
2246 *
2247 * @jls 8.2 Class Members
2248 * @jls 8.4 Method Declarations
2249 * @since 1.1
2250 */
2251 public Method getMethod(String name, Class<?>... parameterTypes)
2252 throws NoSuchMethodException {
2253 Objects.requireNonNull(name);
2254 Method method = getMethod0(name, parameterTypes);
2255 if (method == null) {
2256 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2257 }
2258 return getReflectionFactory().copyMethod(method);
2259 }
2260
2261 /**
2262 * Returns a {@code Constructor} object that reflects the specified
2263 * public constructor of the class represented by this {@code Class}
2264 * object. The {@code parameterTypes} parameter is an array of
2265 * {@code Class} objects that identify the constructor's formal
2266 * parameter types, in declared order.
2267 *
2268 * If this {@code Class} object represents an inner class
2269 * declared in a non-static context, the formal parameter types
2270 * include the explicit enclosing instance as the first parameter.
2271 *
2272 * <p> The constructor to reflect is the public constructor of the class
2273 * represented by this {@code Class} object whose formal parameter
2274 * types match those specified by {@code parameterTypes}.
2275 *
2276 * @param parameterTypes the parameter array
2277 * @return the {@code Constructor} object of the public constructor that
2278 * matches the specified {@code parameterTypes}
2279 * @throws NoSuchMethodException if a matching constructor is not found,
2280 * including when this {@code Class} object represents
2281 * an interface, a primitive type, an array class, or void.
2282 *
2283 * @see #getDeclaredConstructor(Class[])
2284 * @since 1.1
2285 */
2286 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2287 throws NoSuchMethodException {
2288 return getReflectionFactory().copyConstructor(
2289 getConstructor0(parameterTypes, Member.PUBLIC));
2290 }
2291
2292
2293 /**
2294 * Returns an array of {@code Class} objects reflecting all the
2295 * classes and interfaces declared as members of the class represented by
2296 * this {@code Class} object. This includes public, protected, default
2297 * (package) access, and private classes and interfaces declared by the
2298 * class, but excludes inherited classes and interfaces. This method
2299 * returns an array of length 0 if the class declares no classes or
2300 * interfaces as members, or if this {@code Class} object represents a
2301 * primitive type, an array class, or void.
2302 *
2303 * @return the array of {@code Class} objects representing all the
2304 * declared members of this class
2305 *
2306 * @since 1.1
2307 * @jls 8.5 Member Class and Interface Declarations
2308 */
2309 public Class<?>[] getDeclaredClasses() {
2310 return getDeclaredClasses0();
2311 }
2312
2313
2314 /**
2315 * Returns an array of {@code Field} objects reflecting all the fields
2316 * declared by the class or interface represented by this
2317 * {@code Class} object. This includes public, protected, default
2318 * (package) access, and private fields, but excludes inherited fields.
2319 *
2320 * <p> If this {@code Class} object represents a class or interface with no
2321 * declared fields, then this method returns an array of length 0.
2322 *
2323 * <p> If this {@code Class} object represents an array type, a primitive
2324 * type, or void, then this method returns an array of length 0.
2325 *
2326 * <p> The elements in the returned array are not sorted and are not in any
2327 * particular order.
2328 *
2329 * @return the array of {@code Field} objects representing all the
2330 * declared fields of this class
2331 *
2332 * @since 1.1
2333 * @jls 8.2 Class Members
2334 * @jls 8.3 Field Declarations
2335 */
2336 public Field[] getDeclaredFields() {
2337 return copyFields(privateGetDeclaredFields(false));
2338 }
2339
2340 /**
2341 * Returns an array of {@code RecordComponent} objects representing all the
2342 * record components of this record class, or {@code null} if this class is
2343 * not a record class.
2344 *
2345 * <p> The components are returned in the same order that they are declared
2346 * in the record header. The array is empty if this record class has no
2347 * components. If the class is not a record class, that is {@link
2348 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2349 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2350 * returns a non-null value.
2351 *
2352 * @apiNote
2353 * <p> The following method can be used to find the record canonical constructor:
2354 *
2355 * {@snippet lang="java" :
2356 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2357 * throws NoSuchMethodException {
2358 * Class<?>[] paramTypes =
2359 * Arrays.stream(cls.getRecordComponents())
2360 * .map(RecordComponent::getType)
2361 * .toArray(Class<?>[]::new);
2362 * return cls.getDeclaredConstructor(paramTypes);
2363 * }}
2364 *
2365 * @return An array of {@code RecordComponent} objects representing all the
2366 * record components of this record class, or {@code null} if this
2367 * class is not a record class
2368 *
2369 * @jls 8.10 Record Classes
2370 * @since 16
2371 */
2372 public RecordComponent[] getRecordComponents() {
2373 if (!isRecord()) {
2374 return null;
2375 }
2376 return getRecordComponents0();
2377 }
2378
2379 /**
2380 * Returns an array containing {@code Method} objects reflecting all the
2381 * declared methods of the class or interface represented by this {@code
2382 * Class} object, including public, protected, default (package)
2383 * access, and private methods, but excluding inherited methods.
2384 * The declared methods may include methods <em>not</em> in the
2385 * source of the class or interface, including {@linkplain
2386 * Method#isBridge bridge methods} and other {@linkplain
2387 * Executable#isSynthetic synthetic} methods added by compilers.
2388 *
2389 * <p> If this {@code Class} object represents a class or interface that
2390 * has multiple declared methods with the same name and parameter types,
2391 * but different return types, then the returned array has a {@code Method}
2392 * object for each such method.
2393 *
2394 * <p> If this {@code Class} object represents a class or interface that
2395 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2396 * then the returned array does <em>not</em> have a corresponding {@code
2397 * Method} object.
2398 *
2399 * <p> If this {@code Class} object represents a class or interface with no
2400 * declared methods, then the returned array has length 0.
2401 *
2402 * <p> If this {@code Class} object represents an array type, a primitive
2403 * type, or void, then the returned array has length 0.
2404 *
2405 * <p> The elements in the returned array are not sorted and are not in any
2406 * particular order.
2407 *
2408 * @return the array of {@code Method} objects representing all the
2409 * declared methods of this class
2410 *
2411 * @jls 8.2 Class Members
2412 * @jls 8.4 Method Declarations
2413 * @see <a
2414 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2415 * programming language and JVM modeling in core reflection</a>
2416 * @since 1.1
2417 */
2418 public Method[] getDeclaredMethods() {
2419 return copyMethods(privateGetDeclaredMethods(false));
2420 }
2421
2422 /**
2423 * Returns an array of {@code Constructor} objects reflecting all the
2424 * constructors implicitly or explicitly declared by the class represented by this
2425 * {@code Class} object. These are public, protected, default
2426 * (package) access, and private constructors. The elements in the array
2427 * returned are not sorted and are not in any particular order. If the
2428 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2429 * If a record class has a canonical constructor (JLS {@jls
2430 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2431 *
2432 * This method returns an array of length 0 if this {@code Class}
2433 * object represents an interface, a primitive type, an array class, or
2434 * void.
2435 *
2436 * @return the array of {@code Constructor} objects representing all the
2437 * declared constructors of this class
2438 *
2439 * @since 1.1
2440 * @see #getConstructors()
2441 * @jls 8.8 Constructor Declarations
2442 */
2443 public Constructor<?>[] getDeclaredConstructors() {
2444 return copyConstructors(privateGetDeclaredConstructors(false));
2445 }
2446
2447
2448 /**
2449 * Returns a {@code Field} object that reflects the specified declared
2450 * field of the class or interface represented by this {@code Class}
2451 * object. The {@code name} parameter is a {@code String} that specifies
2452 * the simple name of the desired field.
2453 *
2454 * <p> If this {@code Class} object represents an array type, then this
2455 * method does not find the {@code length} field of the array type.
2456 *
2457 * @param name the name of the field
2458 * @return the {@code Field} object for the specified field in this
2459 * class
2460 * @throws NoSuchFieldException if a field with the specified name is
2461 * not found.
2462 * @throws NullPointerException if {@code name} is {@code null}
2463 *
2464 * @since 1.1
2465 * @jls 8.2 Class Members
2466 * @jls 8.3 Field Declarations
2467 */
2468 public Field getDeclaredField(String name) throws NoSuchFieldException {
2469 Objects.requireNonNull(name);
2470 Field field = searchFields(privateGetDeclaredFields(false), name);
2471 if (field == null) {
2472 throw new NoSuchFieldException(name);
2473 }
2474 return getReflectionFactory().copyField(field);
2475 }
2476
2477
2478 /**
2479 * Returns a {@code Method} object that reflects the specified
2480 * declared method of the class or interface represented by this
2481 * {@code Class} object. The {@code name} parameter is a
2482 * {@code String} that specifies the simple name of the desired
2483 * method, and the {@code parameterTypes} parameter is an array of
2484 * {@code Class} objects that identify the method's formal parameter
2485 * types, in declared order. If more than one method with the same
2486 * parameter types is declared in a class, and one of these methods has a
2487 * return type that is more specific than any of the others, that method is
2488 * returned; otherwise one of the methods is chosen arbitrarily. If the
2489 * name is {@value ConstantDescs#INIT_NAME} or {@value
2490 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2491 * is raised.
2492 *
2493 * <p> If this {@code Class} object represents an array type, then this
2494 * method does not find the {@code clone()} method.
2495 *
2496 * @param name the name of the method
2497 * @param parameterTypes the parameter array
2498 * @return the {@code Method} object for the method of this class
2499 * matching the specified name and parameters
2500 * @throws NoSuchMethodException if a matching method is not found.
2501 * @throws NullPointerException if {@code name} is {@code null}
2502 *
2503 * @jls 8.2 Class Members
2504 * @jls 8.4 Method Declarations
2505 * @since 1.1
2506 */
2507 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2508 throws NoSuchMethodException {
2509 Objects.requireNonNull(name);
2510 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2511 if (method == null) {
2512 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2513 }
2514 return getReflectionFactory().copyMethod(method);
2515 }
2516
2517 /**
2518 * Returns the list of {@code Method} objects for the declared public
2519 * methods of this class or interface that have the specified method name
2520 * and parameter types.
2521 *
2522 * @param name the name of the method
2523 * @param parameterTypes the parameter array
2524 * @return the list of {@code Method} objects for the public methods of
2525 * this class matching the specified name and parameters
2526 */
2527 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2528 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2529 ReflectionFactory factory = getReflectionFactory();
2530 List<Method> result = new ArrayList<>();
2531 for (Method method : methods) {
2532 if (method.getName().equals(name)
2533 && Arrays.equals(
2534 factory.getExecutableSharedParameterTypes(method),
2535 parameterTypes)) {
2536 result.add(factory.copyMethod(method));
2537 }
2538 }
2539 return result;
2540 }
2541
2542 /**
2543 * Returns the most specific {@code Method} object of this class, super class or
2544 * interface that have the specified method name and parameter types.
2545 *
2546 * @param publicOnly true if only public methods are examined, otherwise all methods
2547 * @param name the name of the method
2548 * @param parameterTypes the parameter array
2549 * @return the {@code Method} object for the method found from this class matching
2550 * the specified name and parameters, or null if not found
2551 */
2552 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2553 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2554 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2555 }
2556
2557 /**
2558 * Returns a {@code Constructor} object that reflects the specified
2559 * constructor of the class represented by this
2560 * {@code Class} object. The {@code parameterTypes} parameter is
2561 * an array of {@code Class} objects that identify the constructor's
2562 * formal parameter types, in declared order.
2563 *
2564 * If this {@code Class} object represents an inner class
2565 * declared in a non-static context, the formal parameter types
2566 * include the explicit enclosing instance as the first parameter.
2567 *
2568 * @param parameterTypes the parameter array
2569 * @return The {@code Constructor} object for the constructor with the
2570 * specified parameter list
2571 * @throws NoSuchMethodException if a matching constructor is not found,
2572 * including when this {@code Class} object represents
2573 * an interface, a primitive type, an array class, or void.
2574 *
2575 * @see #getConstructor(Class[])
2576 * @since 1.1
2577 */
2578 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2579 throws NoSuchMethodException {
2580 return getReflectionFactory().copyConstructor(
2581 getConstructor0(parameterTypes, Member.DECLARED));
2582 }
2583
2584 /**
2585 * Finds a resource with a given name.
2586 *
2587 * <p> If this class is in a named {@link Module Module} then this method
2588 * will attempt to find the resource in the module. This is done by
2589 * delegating to the module's class loader {@link
2590 * ClassLoader#findResource(String,String) findResource(String,String)}
2591 * method, invoking it with the module name and the absolute name of the
2592 * resource. Resources in named modules are subject to the rules for
2593 * encapsulation specified in the {@code Module} {@link
2594 * Module#getResourceAsStream getResourceAsStream} method and so this
2595 * method returns {@code null} when the resource is a
2596 * non-"{@code .class}" resource in a package that is not open to the
2597 * caller's module.
2598 *
2599 * <p> Otherwise, if this class is not in a named module then the rules for
2600 * searching resources associated with a given class are implemented by the
2601 * defining {@linkplain ClassLoader class loader} of the class. This method
2602 * delegates to this {@code Class} object's class loader.
2603 * If this {@code Class} object was loaded by the bootstrap class loader,
2604 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2605 *
2606 * <p> Before delegation, an absolute resource name is constructed from the
2607 * given resource name using this algorithm:
2608 *
2609 * <ul>
2610 *
2611 * <li> If the {@code name} begins with a {@code '/'}
2612 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2613 * portion of the {@code name} following the {@code '/'}.
2614 *
2615 * <li> Otherwise, the absolute name is of the following form:
2616 *
2617 * <blockquote>
2618 * {@code modified_package_name/name}
2619 * </blockquote>
2620 *
2621 * <p> Where the {@code modified_package_name} is the package name of this
2622 * object with {@code '/'} substituted for {@code '.'}
2623 * (<code>'\u002e'</code>).
2624 *
2625 * </ul>
2626 *
2627 * @param name name of the desired resource
2628 * @return A {@link java.io.InputStream} object; {@code null} if no
2629 * resource with this name is found, or the resource is in a package
2630 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2631 * least the caller module.
2632 * @throws NullPointerException If {@code name} is {@code null}
2633 *
2634 * @see Module#getResourceAsStream(String)
2635 * @since 1.1
2636 */
2637 @CallerSensitive
2638 public InputStream getResourceAsStream(String name) {
2639 name = resolveName(name);
2640
2641 Module thisModule = getModule();
2642 if (thisModule.isNamed()) {
2643 // check if resource can be located by caller
2644 if (Resources.canEncapsulate(name)
2645 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2646 return null;
2647 }
2648
2649 // resource not encapsulated or in package open to caller
2650 String mn = thisModule.getName();
2651 ClassLoader cl = classLoader;
2652 try {
2653
2654 // special-case built-in class loaders to avoid the
2655 // need for a URL connection
2656 if (cl == null) {
2657 return BootLoader.findResourceAsStream(mn, name);
2658 } else if (cl instanceof BuiltinClassLoader bcl) {
2659 return bcl.findResourceAsStream(mn, name);
2660 } else {
2661 URL url = cl.findResource(mn, name);
2662 return (url != null) ? url.openStream() : null;
2663 }
2664
2665 } catch (IOException | SecurityException e) {
2666 return null;
2667 }
2668 }
2669
2670 // unnamed module
2671 ClassLoader cl = classLoader;
2672 if (cl == null) {
2673 return ClassLoader.getSystemResourceAsStream(name);
2674 } else {
2675 return cl.getResourceAsStream(name);
2676 }
2677 }
2678
2679 /**
2680 * Finds a resource with a given name.
2681 *
2682 * <p> If this class is in a named {@link Module Module} then this method
2683 * will attempt to find the resource in the module. This is done by
2684 * delegating to the module's class loader {@link
2685 * ClassLoader#findResource(String,String) findResource(String,String)}
2686 * method, invoking it with the module name and the absolute name of the
2687 * resource. Resources in named modules are subject to the rules for
2688 * encapsulation specified in the {@code Module} {@link
2689 * Module#getResourceAsStream getResourceAsStream} method and so this
2690 * method returns {@code null} when the resource is a
2691 * non-"{@code .class}" resource in a package that is not open to the
2692 * caller's module.
2693 *
2694 * <p> Otherwise, if this class is not in a named module then the rules for
2695 * searching resources associated with a given class are implemented by the
2696 * defining {@linkplain ClassLoader class loader} of the class. This method
2697 * delegates to this {@code Class} object's class loader.
2698 * If this {@code Class} object was loaded by the bootstrap class loader,
2699 * the method delegates to {@link ClassLoader#getSystemResource}.
2700 *
2701 * <p> Before delegation, an absolute resource name is constructed from the
2702 * given resource name using this algorithm:
2703 *
2704 * <ul>
2705 *
2706 * <li> If the {@code name} begins with a {@code '/'}
2707 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2708 * portion of the {@code name} following the {@code '/'}.
2709 *
2710 * <li> Otherwise, the absolute name is of the following form:
2711 *
2712 * <blockquote>
2713 * {@code modified_package_name/name}
2714 * </blockquote>
2715 *
2716 * <p> Where the {@code modified_package_name} is the package name of this
2717 * object with {@code '/'} substituted for {@code '.'}
2718 * (<code>'\u002e'</code>).
2719 *
2720 * </ul>
2721 *
2722 * @param name name of the desired resource
2723 * @return A {@link java.net.URL} object; {@code null} if no resource with
2724 * this name is found, the resource cannot be located by a URL, or the
2725 * resource is in a package that is not
2726 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2727 * module.
2728 * @throws NullPointerException If {@code name} is {@code null}
2729 * @since 1.1
2730 */
2731 @CallerSensitive
2732 public URL getResource(String name) {
2733 name = resolveName(name);
2734
2735 Module thisModule = getModule();
2736 if (thisModule.isNamed()) {
2737 // check if resource can be located by caller
2738 if (Resources.canEncapsulate(name)
2739 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2740 return null;
2741 }
2742
2743 // resource not encapsulated or in package open to caller
2744 String mn = thisModule.getName();
2745 ClassLoader cl = classLoader;
2746 try {
2747 if (cl == null) {
2748 return BootLoader.findResource(mn, name);
2749 } else {
2750 return cl.findResource(mn, name);
2751 }
2752 } catch (IOException ioe) {
2753 return null;
2754 }
2755 }
2756
2757 // unnamed module
2758 ClassLoader cl = classLoader;
2759 if (cl == null) {
2760 return ClassLoader.getSystemResource(name);
2761 } else {
2762 return cl.getResource(name);
2763 }
2764 }
2765
2766 /**
2767 * Returns true if a resource with the given name can be located by the
2768 * given caller. All resources in a module can be located by code in
2769 * the module. For other callers, then the package needs to be open to
2770 * the caller.
2771 */
2772 private boolean isOpenToCaller(String name, Class<?> caller) {
2773 // assert getModule().isNamed();
2774 Module thisModule = getModule();
2775 Module callerModule = (caller != null) ? caller.getModule() : null;
2776 if (callerModule != thisModule) {
2777 String pn = Resources.toPackageName(name);
2778 if (thisModule.getDescriptor().packages().contains(pn)) {
2779 if (callerModule == null) {
2780 // no caller, return true if the package is open to all modules
2781 return thisModule.isOpen(pn);
2782 }
2783 if (!thisModule.isOpen(pn, callerModule)) {
2784 // package not open to caller
2785 return false;
2786 }
2787 }
2788 }
2789 return true;
2790 }
2791
2792 private transient final ProtectionDomain protectionDomain;
2793
2794 /** Holder for the protection domain returned when the internal domain is null */
2795 private static class Holder {
2796 private static final ProtectionDomain allPermDomain;
2797 static {
2798 Permissions perms = new Permissions();
2799 perms.add(new AllPermission());
2800 allPermDomain = new ProtectionDomain(null, perms);
2801 }
2802 }
2803
2804 /**
2805 * Returns the {@code ProtectionDomain} of this class.
2806 *
2807 * @return the ProtectionDomain of this class
2808 *
2809 * @see java.security.ProtectionDomain
2810 * @since 1.2
2811 */
2812 public ProtectionDomain getProtectionDomain() {
2813 if (protectionDomain == null) {
2814 return Holder.allPermDomain;
2815 } else {
2816 return protectionDomain;
2817 }
2818 }
2819
2820 /*
2821 * Returns the Class object for the named primitive type. Type parameter T
2822 * avoids redundant casts for trusted code.
2823 */
2824 static native <T> Class<T> getPrimitiveClass(String name);
2825
2826 /**
2827 * Add a package name prefix if the name is not absolute. Remove leading "/"
2828 * if name is absolute
2829 */
2830 private String resolveName(String name) {
2831 if (!name.startsWith("/")) {
2832 String baseName = getPackageName();
2833 if (!baseName.isEmpty()) {
2834 int len = baseName.length() + 1 + name.length();
2835 StringBuilder sb = new StringBuilder(len);
2836 name = sb.append(baseName.replace('.', '/'))
2837 .append('/')
2838 .append(name)
2839 .toString();
2840 }
2841 } else {
2842 name = name.substring(1);
2843 }
2844 return name;
2845 }
2846
2847 /**
2848 * Atomic operations support.
2849 */
2850 private static class Atomic {
2851 // initialize Unsafe machinery here, since we need to call Class.class instance method
2852 // and have to avoid calling it in the static initializer of the Class class...
2853 private static final Unsafe unsafe = Unsafe.getUnsafe();
2854 // offset of Class.reflectionData instance field
2855 private static final long reflectionDataOffset
2856 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2857 // offset of Class.annotationType instance field
2858 private static final long annotationTypeOffset
2859 = unsafe.objectFieldOffset(Class.class, "annotationType");
2860 // offset of Class.annotationData instance field
2861 private static final long annotationDataOffset
2862 = unsafe.objectFieldOffset(Class.class, "annotationData");
2863
2864 static <T> boolean casReflectionData(Class<?> clazz,
2865 SoftReference<ReflectionData<T>> oldData,
2866 SoftReference<ReflectionData<T>> newData) {
2867 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2868 }
2869
2870 static boolean casAnnotationType(Class<?> clazz,
2871 AnnotationType oldType,
2872 AnnotationType newType) {
2873 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2874 }
2875
2876 static boolean casAnnotationData(Class<?> clazz,
2877 AnnotationData oldData,
2878 AnnotationData newData) {
2879 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2880 }
2881 }
2882
2883 /**
2884 * Reflection support.
2885 */
2886
2887 // Reflection data caches various derived names and reflective members. Cached
2888 // values may be invalidated when JVM TI RedefineClasses() is called
2889 private static class ReflectionData<T> {
2890 volatile Field[] declaredFields;
2891 volatile Field[] publicFields;
2892 volatile Method[] declaredMethods;
2893 volatile Method[] publicMethods;
2894 volatile Constructor<T>[] declaredConstructors;
2895 volatile Constructor<T>[] publicConstructors;
2896 // Intermediate results for getFields and getMethods
2897 volatile Field[] declaredPublicFields;
2898 volatile Method[] declaredPublicMethods;
2899 volatile Class<?>[] interfaces;
2900
2901 // Cached names
2902 String simpleName;
2903 String canonicalName;
2904 static final String NULL_SENTINEL = new String();
2905
2906 // Value of classRedefinedCount when we created this ReflectionData instance
2907 final int redefinedCount;
2908
2909 ReflectionData(int redefinedCount) {
2910 this.redefinedCount = redefinedCount;
2911 }
2912 }
2913
2914 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2915
2916 // Incremented by the VM on each call to JVM TI RedefineClasses()
2917 // that redefines this class or a superclass.
2918 private transient volatile int classRedefinedCount;
2919
2920 // Lazily create and cache ReflectionData
2921 private ReflectionData<T> reflectionData() {
2922 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2923 int classRedefinedCount = this.classRedefinedCount;
2924 ReflectionData<T> rd;
2925 if (reflectionData != null &&
2926 (rd = reflectionData.get()) != null &&
2927 rd.redefinedCount == classRedefinedCount) {
2928 return rd;
2929 }
2930 // else no SoftReference or cleared SoftReference or stale ReflectionData
2931 // -> create and replace new instance
2932 return newReflectionData(reflectionData, classRedefinedCount);
2933 }
2934
2935 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2936 int classRedefinedCount) {
2937 while (true) {
2938 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2939 // try to CAS it...
2940 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
2941 return rd;
2942 }
2943 // else retry
2944 oldReflectionData = this.reflectionData;
2945 classRedefinedCount = this.classRedefinedCount;
2946 if (oldReflectionData != null &&
2947 (rd = oldReflectionData.get()) != null &&
2948 rd.redefinedCount == classRedefinedCount) {
2949 return rd;
2950 }
2951 }
2952 }
2953
2954 // Generic signature handling
2955 private native String getGenericSignature0();
2956
2957 // Generic info repository; lazily initialized
2958 private transient volatile ClassRepository genericInfo;
2959
2960 // accessor for factory
2961 private GenericsFactory getFactory() {
2962 // create scope and factory
2963 return CoreReflectionFactory.make(this, ClassScope.make(this));
2964 }
2965
2966 // accessor for generic info repository;
2967 // generic info is lazily initialized
2968 private ClassRepository getGenericInfo() {
2969 ClassRepository genericInfo = this.genericInfo;
2970 if (genericInfo == null) {
2971 String signature = getGenericSignature0();
2972 if (signature == null) {
2973 genericInfo = ClassRepository.NONE;
2974 } else {
2975 genericInfo = ClassRepository.make(signature, getFactory());
2976 }
2977 this.genericInfo = genericInfo;
2978 }
2979 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2980 }
2981
2982 // Annotations handling
2983 native byte[] getRawAnnotations();
2984 // Since 1.8
2985 native byte[] getRawTypeAnnotations();
2986 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2987 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2988 }
2989
2990 native ConstantPool getConstantPool();
2991
2992 //
2993 //
2994 // java.lang.reflect.Field handling
2995 //
2996 //
2997
2998 // Returns an array of "root" fields. These Field objects must NOT
2999 // be propagated to the outside world, but must instead be copied
3000 // via ReflectionFactory.copyField.
3001 private Field[] privateGetDeclaredFields(boolean publicOnly) {
3002 Field[] res;
3003 ReflectionData<T> rd = reflectionData();
3004 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
3005 if (res != null) return res;
3006 // No cached value available; request value from VM
3007 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
3008 if (publicOnly) {
3009 rd.declaredPublicFields = res;
3010 } else {
3011 rd.declaredFields = res;
3012 }
3013 return res;
3014 }
3015
3016 // Returns an array of "root" fields. These Field objects must NOT
3017 // be propagated to the outside world, but must instead be copied
3018 // via ReflectionFactory.copyField.
3019 private Field[] privateGetPublicFields() {
3020 Field[] res;
3021 ReflectionData<T> rd = reflectionData();
3022 res = rd.publicFields;
3023 if (res != null) return res;
3024
3025 // Use a linked hash set to ensure order is preserved and
3026 // fields from common super interfaces are not duplicated
3027 LinkedHashSet<Field> fields = new LinkedHashSet<>();
3028
3029 // Local fields
3030 addAll(fields, privateGetDeclaredFields(true));
3031
3032 // Direct superinterfaces, recursively
3033 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
3034 addAll(fields, si.privateGetPublicFields());
3035 }
3036
3037 // Direct superclass, recursively
3038 Class<?> sc = getSuperclass();
3039 if (sc != null) {
3040 addAll(fields, sc.privateGetPublicFields());
3041 }
3042
3043 res = fields.toArray(new Field[0]);
3044 rd.publicFields = res;
3045 return res;
3046 }
3047
3048 private static void addAll(Collection<Field> c, Field[] o) {
3049 for (Field f : o) {
3050 c.add(f);
3051 }
3052 }
3053
3054
3055 //
3056 //
3057 // java.lang.reflect.Constructor handling
3058 //
3059 //
3060
3061 // Returns an array of "root" constructors. These Constructor
3062 // objects must NOT be propagated to the outside world, but must
3063 // instead be copied via ReflectionFactory.copyConstructor.
3064 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3065 Constructor<T>[] res;
3066 ReflectionData<T> rd = reflectionData();
3067 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3068 if (res != null) return res;
3069 // No cached value available; request value from VM
3070 if (isInterface()) {
3071 @SuppressWarnings("unchecked")
3072 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3073 res = temporaryRes;
3074 } else {
3075 res = getDeclaredConstructors0(publicOnly);
3076 }
3077 if (publicOnly) {
3078 rd.publicConstructors = res;
3079 } else {
3080 rd.declaredConstructors = res;
3081 }
3082 return res;
3083 }
3084
3085 //
3086 //
3087 // java.lang.reflect.Method handling
3088 //
3089 //
3090
3091 // Returns an array of "root" methods. These Method objects must NOT
3092 // be propagated to the outside world, but must instead be copied
3093 // via ReflectionFactory.copyMethod.
3094 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3095 Method[] res;
3096 ReflectionData<T> rd = reflectionData();
3097 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3098 if (res != null) return res;
3099 // No cached value available; request value from VM
3100 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3101 if (publicOnly) {
3102 rd.declaredPublicMethods = res;
3103 } else {
3104 rd.declaredMethods = res;
3105 }
3106 return res;
3107 }
3108
3109 // Returns an array of "root" methods. These Method objects must NOT
3110 // be propagated to the outside world, but must instead be copied
3111 // via ReflectionFactory.copyMethod.
3112 private Method[] privateGetPublicMethods() {
3113 Method[] res;
3114 ReflectionData<T> rd = reflectionData();
3115 res = rd.publicMethods;
3116 if (res != null) return res;
3117
3118 // No cached value available; compute value recursively.
3119 // Start by fetching public declared methods...
3120 PublicMethods pms = new PublicMethods();
3121 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3122 pms.merge(m);
3123 }
3124 // ...then recur over superclass methods...
3125 Class<?> sc = getSuperclass();
3126 if (sc != null) {
3127 for (Method m : sc.privateGetPublicMethods()) {
3128 pms.merge(m);
3129 }
3130 }
3131 // ...and finally over direct superinterfaces.
3132 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3133 for (Method m : intf.privateGetPublicMethods()) {
3134 // static interface methods are not inherited
3135 if (!Modifier.isStatic(m.getModifiers())) {
3136 pms.merge(m);
3137 }
3138 }
3139 }
3140
3141 res = pms.toArray();
3142 rd.publicMethods = res;
3143 return res;
3144 }
3145
3146
3147 //
3148 // Helpers for fetchers of one field, method, or constructor
3149 //
3150
3151 // This method does not copy the returned Field object!
3152 private static Field searchFields(Field[] fields, String name) {
3153 for (Field field : fields) {
3154 if (field.getName().equals(name)) {
3155 return field;
3156 }
3157 }
3158 return null;
3159 }
3160
3161 // Returns a "root" Field object. This Field object must NOT
3162 // be propagated to the outside world, but must instead be copied
3163 // via ReflectionFactory.copyField.
3164 private Field getField0(String name) {
3165 // Note: the intent is that the search algorithm this routine
3166 // uses be equivalent to the ordering imposed by
3167 // privateGetPublicFields(). It fetches only the declared
3168 // public fields for each class, however, to reduce the number
3169 // of Field objects which have to be created for the common
3170 // case where the field being requested is declared in the
3171 // class which is being queried.
3172 Field res;
3173 // Search declared public fields
3174 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3175 return res;
3176 }
3177 // Direct superinterfaces, recursively
3178 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3179 for (Class<?> c : interfaces) {
3180 if ((res = c.getField0(name)) != null) {
3181 return res;
3182 }
3183 }
3184 // Direct superclass, recursively
3185 if (!isInterface()) {
3186 Class<?> c = getSuperclass();
3187 if (c != null) {
3188 if ((res = c.getField0(name)) != null) {
3189 return res;
3190 }
3191 }
3192 }
3193 return null;
3194 }
3195
3196 // This method does not copy the returned Method object!
3197 private static Method searchMethods(Method[] methods,
3198 String name,
3199 Class<?>[] parameterTypes)
3200 {
3201 ReflectionFactory fact = getReflectionFactory();
3202 Method res = null;
3203 for (Method m : methods) {
3204 if (m.getName().equals(name)
3205 && arrayContentsEq(parameterTypes,
3206 fact.getExecutableSharedParameterTypes(m))
3207 && (res == null
3208 || (res.getReturnType() != m.getReturnType()
3209 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3210 res = m;
3211 }
3212 return res;
3213 }
3214
3215 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3216
3217 // Returns a "root" Method object. This Method object must NOT
3218 // be propagated to the outside world, but must instead be copied
3219 // via ReflectionFactory.copyMethod.
3220 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3221 PublicMethods.MethodList res = getMethodsRecursive(
3222 name,
3223 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3224 /* includeStatic */ true, /* publicOnly */ true);
3225 return res == null ? null : res.getMostSpecific();
3226 }
3227
3228 // Returns a list of "root" Method objects. These Method objects must NOT
3229 // be propagated to the outside world, but must instead be copied
3230 // via ReflectionFactory.copyMethod.
3231 private PublicMethods.MethodList getMethodsRecursive(String name,
3232 Class<?>[] parameterTypes,
3233 boolean includeStatic,
3234 boolean publicOnly) {
3235 // 1st check declared methods
3236 Method[] methods = privateGetDeclaredMethods(publicOnly);
3237 PublicMethods.MethodList res = PublicMethods.MethodList
3238 .filter(methods, name, parameterTypes, includeStatic);
3239 // if there is at least one match among declared methods, we need not
3240 // search any further as such match surely overrides matching methods
3241 // declared in superclass(es) or interface(s).
3242 if (res != null) {
3243 return res;
3244 }
3245
3246 // if there was no match among declared methods,
3247 // we must consult the superclass (if any) recursively...
3248 Class<?> sc = getSuperclass();
3249 if (sc != null) {
3250 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3251 }
3252
3253 // ...and coalesce the superclass methods with methods obtained
3254 // from directly implemented interfaces excluding static methods...
3255 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3256 res = PublicMethods.MethodList.merge(
3257 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3258 }
3259
3260 return res;
3261 }
3262
3263 // Returns a "root" Constructor object. This Constructor object must NOT
3264 // be propagated to the outside world, but must instead be copied
3265 // via ReflectionFactory.copyConstructor.
3266 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3267 int which) throws NoSuchMethodException
3268 {
3269 ReflectionFactory fact = getReflectionFactory();
3270 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3271 for (Constructor<T> constructor : constructors) {
3272 if (arrayContentsEq(parameterTypes,
3273 fact.getExecutableSharedParameterTypes(constructor))) {
3274 return constructor;
3275 }
3276 }
3277 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3278 }
3279
3280 //
3281 // Other helpers and base implementation
3282 //
3283
3284 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3285 if (a1 == null) {
3286 return a2 == null || a2.length == 0;
3287 }
3288
3289 if (a2 == null) {
3290 return a1.length == 0;
3291 }
3292
3293 if (a1.length != a2.length) {
3294 return false;
3295 }
3296
3297 for (int i = 0; i < a1.length; i++) {
3298 if (a1[i] != a2[i]) {
3299 return false;
3300 }
3301 }
3302
3303 return true;
3304 }
3305
3306 private static Field[] copyFields(Field[] arg) {
3307 Field[] out = new Field[arg.length];
3308 ReflectionFactory fact = getReflectionFactory();
3309 for (int i = 0; i < arg.length; i++) {
3310 out[i] = fact.copyField(arg[i]);
3311 }
3312 return out;
3313 }
3314
3315 private static Method[] copyMethods(Method[] arg) {
3316 Method[] out = new Method[arg.length];
3317 ReflectionFactory fact = getReflectionFactory();
3318 for (int i = 0; i < arg.length; i++) {
3319 out[i] = fact.copyMethod(arg[i]);
3320 }
3321 return out;
3322 }
3323
3324 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3325 Constructor<U>[] out = arg.clone();
3326 ReflectionFactory fact = getReflectionFactory();
3327 for (int i = 0; i < out.length; i++) {
3328 out[i] = fact.copyConstructor(out[i]);
3329 }
3330 return out;
3331 }
3332
3333 private native Field[] getDeclaredFields0(boolean publicOnly);
3334 private native Method[] getDeclaredMethods0(boolean publicOnly);
3335 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3336 private native Class<?>[] getDeclaredClasses0();
3337
3338 /*
3339 * Returns an array containing the components of the Record attribute,
3340 * or null if the attribute is not present.
3341 *
3342 * Note that this method returns non-null array on a class with
3343 * the Record attribute even if this class is not a record.
3344 */
3345 private native RecordComponent[] getRecordComponents0();
3346 private native boolean isRecord0();
3347
3348 /**
3349 * Helper method to get the method name from arguments.
3350 */
3351 private String methodToString(String name, Class<?>[] argTypes) {
3352 return getName() + '.' + name +
3353 ((argTypes == null || argTypes.length == 0) ?
3354 "()" :
3355 Arrays.stream(argTypes)
3356 .map(c -> c == null ? "null" : c.getName())
3357 .collect(Collectors.joining(",", "(", ")")));
3358 }
3359
3360 /** use serialVersionUID from JDK 1.1 for interoperability */
3361 @java.io.Serial
3362 private static final long serialVersionUID = 3206093459760846163L;
3363
3364
3365 /**
3366 * Class Class is special cased within the Serialization Stream Protocol.
3367 *
3368 * A Class instance is written initially into an ObjectOutputStream in the
3369 * following format:
3370 * <pre>
3371 * {@code TC_CLASS} ClassDescriptor
3372 * A ClassDescriptor is a special cased serialization of
3373 * a {@code java.io.ObjectStreamClass} instance.
3374 * </pre>
3375 * A new handle is generated for the initial time the class descriptor
3376 * is written into the stream. Future references to the class descriptor
3377 * are written as references to the initial class descriptor instance.
3378 *
3379 * @see java.io.ObjectStreamClass
3380 */
3381 @java.io.Serial
3382 private static final ObjectStreamField[] serialPersistentFields =
3383 new ObjectStreamField[0];
3384
3385
3386 /**
3387 * Returns the assertion status that would be assigned to this
3388 * class if it were to be initialized at the time this method is invoked.
3389 * If this class has had its assertion status set, the most recent
3390 * setting will be returned; otherwise, if any package default assertion
3391 * status pertains to this class, the most recent setting for the most
3392 * specific pertinent package default assertion status is returned;
3393 * otherwise, if this class is not a system class (i.e., it has a
3394 * class loader) its class loader's default assertion status is returned;
3395 * otherwise, the system class default assertion status is returned.
3396 *
3397 * @apiNote
3398 * Few programmers will have any need for this method; it is provided
3399 * for the benefit of the JDK itself. (It allows a class to determine at
3400 * the time that it is initialized whether assertions should be enabled.)
3401 * Note that this method is not guaranteed to return the actual
3402 * assertion status that was (or will be) associated with the specified
3403 * class when it was (or will be) initialized.
3404 *
3405 * @return the desired assertion status of the specified class.
3406 * @see java.lang.ClassLoader#setClassAssertionStatus
3407 * @see java.lang.ClassLoader#setPackageAssertionStatus
3408 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3409 * @since 1.4
3410 */
3411 public boolean desiredAssertionStatus() {
3412 ClassLoader loader = classLoader;
3413 // If the loader is null this is a system class, so ask the VM
3414 if (loader == null)
3415 return desiredAssertionStatus0(this);
3416
3417 // If the classloader has been initialized with the assertion
3418 // directives, ask it. Otherwise, ask the VM.
3419 synchronized(loader.assertionLock) {
3420 if (loader.classAssertionStatus != null) {
3421 return loader.desiredAssertionStatus(getName());
3422 }
3423 }
3424 return desiredAssertionStatus0(this);
3425 }
3426
3427 // Retrieves the desired assertion status of this class from the VM
3428 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3429
3430 /**
3431 * Returns true if and only if this class was declared as an enum in the
3432 * source code.
3433 *
3434 * Note that {@link java.lang.Enum} is not itself an enum class.
3435 *
3436 * Also note that if an enum constant is declared with a class body,
3437 * the class of that enum constant object is an anonymous class
3438 * and <em>not</em> the class of the declaring enum class. The
3439 * {@link Enum#getDeclaringClass} method of an enum constant can
3440 * be used to get the class of the enum class declaring the
3441 * constant.
3442 *
3443 * @return true if and only if this class was declared as an enum in the
3444 * source code
3445 * @since 1.5
3446 * @jls 8.9.1 Enum Constants
3447 */
3448 public boolean isEnum() {
3449 // An enum must both directly extend java.lang.Enum and have
3450 // the ENUM bit set; classes for specialized enum constants
3451 // don't do the former.
3452 return (this.getModifiers() & ENUM) != 0 &&
3453 this.getSuperclass() == java.lang.Enum.class;
3454 }
3455
3456 /**
3457 * Returns {@code true} if and only if this class is a record class.
3458 *
3459 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3460 * class is {@code java.lang.Record}. A record class is {@linkplain
3461 * Modifier#FINAL final}. A record class has (possibly zero) record
3462 * components; {@link #getRecordComponents()} returns a non-null but
3463 * possibly empty value for a record.
3464 *
3465 * <p> Note that class {@link Record} is not a record class and thus
3466 * invoking this method on class {@code Record} returns {@code false}.
3467 *
3468 * @return true if and only if this class is a record class, otherwise false
3469 * @jls 8.10 Record Classes
3470 * @since 16
3471 */
3472 public boolean isRecord() {
3473 // this superclass and final modifier check is not strictly necessary
3474 // they are intrinsified and serve as a fast-path check
3475 return getSuperclass() == java.lang.Record.class &&
3476 (this.getModifiers() & Modifier.FINAL) != 0 &&
3477 isRecord0();
3478 }
3479
3480 // Fetches the factory for reflective objects
3481 private static ReflectionFactory getReflectionFactory() {
3482 var factory = reflectionFactory;
3483 if (factory != null) {
3484 return factory;
3485 }
3486 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3487 }
3488 private static ReflectionFactory reflectionFactory;
3489
3490 /**
3491 * When CDS is enabled, the Class class may be aot-initialized. However,
3492 * we can't archive reflectionFactory, so we reset it to null, so it
3493 * will be allocated again at runtime.
3494 */
3495 private static void resetArchivedStates() {
3496 reflectionFactory = null;
3497 }
3498
3499 /**
3500 * Returns the elements of this enum class or null if this
3501 * Class object does not represent an enum class.
3502 *
3503 * @return an array containing the values comprising the enum class
3504 * represented by this {@code Class} object in the order they're
3505 * declared, or null if this {@code Class} object does not
3506 * represent an enum class
3507 * @since 1.5
3508 * @jls 8.9.1 Enum Constants
3509 */
3510 public T[] getEnumConstants() {
3511 T[] values = getEnumConstantsShared();
3512 return (values != null) ? values.clone() : null;
3513 }
3514
3515 /**
3516 * Returns the elements of this enum class or null if this
3517 * Class object does not represent an enum class;
3518 * identical to getEnumConstants except that the result is
3519 * uncloned, cached, and shared by all callers.
3520 */
3521 T[] getEnumConstantsShared() {
3522 T[] constants = enumConstants;
3523 if (constants == null) {
3524 if (!isEnum()) return null;
3525 try {
3526 final Method values = getMethod("values");
3527 values.setAccessible(true);
3528 @SuppressWarnings("unchecked")
3529 T[] temporaryConstants = (T[])values.invoke(null);
3530 enumConstants = constants = temporaryConstants;
3531 }
3532 // These can happen when users concoct enum-like classes
3533 // that don't comply with the enum spec.
3534 catch (InvocationTargetException | NoSuchMethodException |
3535 IllegalAccessException | NullPointerException |
3536 ClassCastException ex) { return null; }
3537 }
3538 return constants;
3539 }
3540 private transient volatile T[] enumConstants;
3541
3542 /**
3543 * Returns a map from simple name to enum constant. This package-private
3544 * method is used internally by Enum to implement
3545 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3546 * efficiently. Note that the map is returned by this method is
3547 * created lazily on first use. Typically it won't ever get created.
3548 */
3549 Map<String, T> enumConstantDirectory() {
3550 Map<String, T> directory = enumConstantDirectory;
3551 if (directory == null) {
3552 T[] universe = getEnumConstantsShared();
3553 if (universe == null)
3554 throw new IllegalArgumentException(
3555 getName() + " is not an enum class");
3556 directory = HashMap.newHashMap(universe.length);
3557 for (T constant : universe) {
3558 directory.put(((Enum<?>)constant).name(), constant);
3559 }
3560 enumConstantDirectory = directory;
3561 }
3562 return directory;
3563 }
3564 private transient volatile Map<String, T> enumConstantDirectory;
3565
3566 /**
3567 * Casts an object to the class or interface represented
3568 * by this {@code Class} object.
3569 *
3570 * @param obj the object to be cast
3571 * @return the object after casting, or null if obj is null
3572 *
3573 * @throws ClassCastException if the object is not
3574 * null and is not assignable to the type T.
3575 *
3576 * @since 1.5
3577 */
3578 @SuppressWarnings("unchecked")
3579 @IntrinsicCandidate
3580 public T cast(Object obj) {
3581 if (obj != null && !isInstance(obj))
3582 throw new ClassCastException(cannotCastMsg(obj));
3583 return (T) obj;
3584 }
3585
3586 private String cannotCastMsg(Object obj) {
3587 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3588 }
3589
3590 /**
3591 * Casts this {@code Class} object to represent a subclass of the class
3592 * represented by the specified class object. Checks that the cast
3593 * is valid, and throws a {@code ClassCastException} if it is not. If
3594 * this method succeeds, it always returns a reference to this {@code Class} object.
3595 *
3596 * <p>This method is useful when a client needs to "narrow" the type of
3597 * a {@code Class} object to pass it to an API that restricts the
3598 * {@code Class} objects that it is willing to accept. A cast would
3599 * generate a compile-time warning, as the correctness of the cast
3600 * could not be checked at runtime (because generic types are implemented
3601 * by erasure).
3602 *
3603 * @param <U> the type to cast this {@code Class} object to
3604 * @param clazz the class of the type to cast this {@code Class} object to
3605 * @return this {@code Class} object, cast to represent a subclass of
3606 * the specified class object.
3607 * @throws ClassCastException if this {@code Class} object does not
3608 * represent a subclass of the specified class (here "subclass" includes
3609 * the class itself).
3610 * @since 1.5
3611 */
3612 @SuppressWarnings("unchecked")
3613 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3614 if (clazz.isAssignableFrom(this))
3615 return (Class<? extends U>) this;
3616 else
3617 throw new ClassCastException(this.toString());
3618 }
3619
3620 /**
3621 * {@inheritDoc}
3622 * <p>Note that any annotation returned by this method is a
3623 * declaration annotation.
3624 *
3625 * @throws NullPointerException {@inheritDoc}
3626 * @since 1.5
3627 */
3628 @Override
3629 @SuppressWarnings("unchecked")
3630 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3631 Objects.requireNonNull(annotationClass);
3632
3633 return (A) annotationData().annotations.get(annotationClass);
3634 }
3635
3636 /**
3637 * {@inheritDoc}
3638 * @throws NullPointerException {@inheritDoc}
3639 * @since 1.5
3640 */
3641 @Override
3642 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3643 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3644 }
3645
3646 /**
3647 * {@inheritDoc}
3648 * <p>Note that any annotations returned by this method are
3649 * declaration annotations.
3650 *
3651 * @throws NullPointerException {@inheritDoc}
3652 * @since 1.8
3653 */
3654 @Override
3655 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3656 Objects.requireNonNull(annotationClass);
3657
3658 AnnotationData annotationData = annotationData();
3659 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3660 this,
3661 annotationClass);
3662 }
3663
3664 /**
3665 * {@inheritDoc}
3666 * <p>Note that any annotations returned by this method are
3667 * declaration annotations.
3668 *
3669 * @since 1.5
3670 */
3671 @Override
3672 public Annotation[] getAnnotations() {
3673 return AnnotationParser.toArray(annotationData().annotations);
3674 }
3675
3676 /**
3677 * {@inheritDoc}
3678 * <p>Note that any annotation returned by this method is a
3679 * declaration annotation.
3680 *
3681 * @throws NullPointerException {@inheritDoc}
3682 * @since 1.8
3683 */
3684 @Override
3685 @SuppressWarnings("unchecked")
3686 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3687 Objects.requireNonNull(annotationClass);
3688
3689 return (A) annotationData().declaredAnnotations.get(annotationClass);
3690 }
3691
3692 /**
3693 * {@inheritDoc}
3694 * <p>Note that any annotations returned by this method are
3695 * declaration annotations.
3696 *
3697 * @throws NullPointerException {@inheritDoc}
3698 * @since 1.8
3699 */
3700 @Override
3701 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3702 Objects.requireNonNull(annotationClass);
3703
3704 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3705 annotationClass);
3706 }
3707
3708 /**
3709 * {@inheritDoc}
3710 * <p>Note that any annotations returned by this method are
3711 * declaration annotations.
3712 *
3713 * @since 1.5
3714 */
3715 @Override
3716 public Annotation[] getDeclaredAnnotations() {
3717 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3718 }
3719
3720 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3721 private static class AnnotationData {
3722 final Map<Class<? extends Annotation>, Annotation> annotations;
3723 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3724
3725 // Value of classRedefinedCount when we created this AnnotationData instance
3726 final int redefinedCount;
3727
3728 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3729 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3730 int redefinedCount) {
3731 this.annotations = annotations;
3732 this.declaredAnnotations = declaredAnnotations;
3733 this.redefinedCount = redefinedCount;
3734 }
3735 }
3736
3737 // Annotations cache
3738 @SuppressWarnings("UnusedDeclaration")
3739 private transient volatile AnnotationData annotationData;
3740
3741 private AnnotationData annotationData() {
3742 while (true) { // retry loop
3743 AnnotationData annotationData = this.annotationData;
3744 int classRedefinedCount = this.classRedefinedCount;
3745 if (annotationData != null &&
3746 annotationData.redefinedCount == classRedefinedCount) {
3747 return annotationData;
3748 }
3749 // null or stale annotationData -> optimistically create new instance
3750 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3751 // try to install it
3752 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3753 // successfully installed new AnnotationData
3754 return newAnnotationData;
3755 }
3756 }
3757 }
3758
3759 private AnnotationData createAnnotationData(int classRedefinedCount) {
3760 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3761 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3762 Class<?> superClass = getSuperclass();
3763 Map<Class<? extends Annotation>, Annotation> annotations = null;
3764 if (superClass != null) {
3765 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3766 superClass.annotationData().annotations;
3767 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3768 Class<? extends Annotation> annotationClass = e.getKey();
3769 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3770 if (annotations == null) { // lazy construction
3771 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3772 declaredAnnotations.size(),
3773 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3774 )
3775 );
3776 }
3777 annotations.put(annotationClass, e.getValue());
3778 }
3779 }
3780 }
3781 if (annotations == null) {
3782 // no inherited annotations -> share the Map with declaredAnnotations
3783 annotations = declaredAnnotations;
3784 } else {
3785 // at least one inherited annotation -> declared may override inherited
3786 annotations.putAll(declaredAnnotations);
3787 }
3788 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3789 }
3790
3791 // Annotation interfaces cache their internal (AnnotationType) form
3792
3793 @SuppressWarnings("UnusedDeclaration")
3794 private transient volatile AnnotationType annotationType;
3795
3796 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3797 return Atomic.casAnnotationType(this, oldType, newType);
3798 }
3799
3800 AnnotationType getAnnotationType() {
3801 return annotationType;
3802 }
3803
3804 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3805 return annotationData().declaredAnnotations;
3806 }
3807
3808 /* Backing store of user-defined values pertaining to this class.
3809 * Maintained by the ClassValue class.
3810 */
3811 transient ClassValue.ClassValueMap classValueMap;
3812
3813 /**
3814 * Returns an {@code AnnotatedType} object that represents the use of a
3815 * type to specify the superclass of the entity represented by this {@code
3816 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3817 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3818 * Foo.)
3819 *
3820 * <p> If this {@code Class} object represents a class whose declaration
3821 * does not explicitly indicate an annotated superclass, then the return
3822 * value is an {@code AnnotatedType} object representing an element with no
3823 * annotations.
3824 *
3825 * <p> If this {@code Class} represents either the {@code Object} class, an
3826 * interface type, an array type, a primitive type, or void, the return
3827 * value is {@code null}.
3828 *
3829 * @return an object representing the superclass
3830 * @since 1.8
3831 */
3832 public AnnotatedType getAnnotatedSuperclass() {
3833 if (this == Object.class ||
3834 isInterface() ||
3835 isArray() ||
3836 isPrimitive() ||
3837 this == Void.TYPE) {
3838 return null;
3839 }
3840
3841 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3842 }
3843
3844 /**
3845 * Returns an array of {@code AnnotatedType} objects that represent the use
3846 * of types to specify superinterfaces of the entity represented by this
3847 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3848 * superinterface in '... implements Foo' is distinct from the
3849 * <em>declaration</em> of interface Foo.)
3850 *
3851 * <p> If this {@code Class} object represents a class, the return value is
3852 * an array containing objects representing the uses of interface types to
3853 * specify interfaces implemented by the class. The order of the objects in
3854 * the array corresponds to the order of the interface types used in the
3855 * 'implements' clause of the declaration of this {@code Class} object.
3856 *
3857 * <p> If this {@code Class} object represents an interface, the return
3858 * value is an array containing objects representing the uses of interface
3859 * types to specify interfaces directly extended by the interface. The
3860 * order of the objects in the array corresponds to the order of the
3861 * interface types used in the 'extends' clause of the declaration of this
3862 * {@code Class} object.
3863 *
3864 * <p> If this {@code Class} object represents a class or interface whose
3865 * declaration does not explicitly indicate any annotated superinterfaces,
3866 * the return value is an array of length 0.
3867 *
3868 * <p> If this {@code Class} object represents either the {@code Object}
3869 * class, an array type, a primitive type, or void, the return value is an
3870 * array of length 0.
3871 *
3872 * @return an array representing the superinterfaces
3873 * @since 1.8
3874 */
3875 public AnnotatedType[] getAnnotatedInterfaces() {
3876 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3877 }
3878
3879 private native Class<?> getNestHost0();
3880
3881 /**
3882 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3883 * or interface represented by this {@code Class} object belongs.
3884 * Every class and interface belongs to exactly one nest.
3885 *
3886 * If the nest host of this class or interface has previously
3887 * been determined, then this method returns the nest host.
3888 * If the nest host of this class or interface has
3889 * not previously been determined, then this method determines the nest
3890 * host using the algorithm of JVMS 5.4.4, and returns it.
3891 *
3892 * Often, a class or interface belongs to a nest consisting only of itself,
3893 * in which case this method returns {@code this} to indicate that the class
3894 * or interface is the nest host.
3895 *
3896 * <p>If this {@code Class} object represents a primitive type, an array type,
3897 * or {@code void}, then this method returns {@code this},
3898 * indicating that the represented entity belongs to the nest consisting only of
3899 * itself, and is the nest host.
3900 *
3901 * @return the nest host of this class or interface
3902 *
3903 * @since 11
3904 * @jvms 4.7.28 The {@code NestHost} Attribute
3905 * @jvms 4.7.29 The {@code NestMembers} Attribute
3906 * @jvms 5.4.4 Access Control
3907 */
3908 public Class<?> getNestHost() {
3909 if (isPrimitive() || isArray()) {
3910 return this;
3911 }
3912 return getNestHost0();
3913 }
3914
3915 /**
3916 * Determines if the given {@code Class} is a nestmate of the
3917 * class or interface represented by this {@code Class} object.
3918 * Two classes or interfaces are nestmates
3919 * if they have the same {@linkplain #getNestHost() nest host}.
3920 *
3921 * @param c the class to check
3922 * @return {@code true} if this class and {@code c} are members of
3923 * the same nest; and {@code false} otherwise.
3924 *
3925 * @since 11
3926 */
3927 public boolean isNestmateOf(Class<?> c) {
3928 if (this == c) {
3929 return true;
3930 }
3931 if (isPrimitive() || isArray() ||
3932 c.isPrimitive() || c.isArray()) {
3933 return false;
3934 }
3935
3936 return getNestHost() == c.getNestHost();
3937 }
3938
3939 private native Class<?>[] getNestMembers0();
3940
3941 /**
3942 * Returns an array containing {@code Class} objects representing all the
3943 * classes and interfaces that are members of the nest to which the class
3944 * or interface represented by this {@code Class} object belongs.
3945 *
3946 * First, this method obtains the {@linkplain #getNestHost() nest host},
3947 * {@code H}, of the nest to which the class or interface represented by
3948 * this {@code Class} object belongs. The zeroth element of the returned
3949 * array is {@code H}.
3950 *
3951 * Then, for each class or interface {@code C} which is recorded by {@code H}
3952 * as being a member of its nest, this method attempts to obtain the {@code Class}
3953 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3954 * loader} of the current {@code Class} object), and then obtains the
3955 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3956 * The classes and interfaces which are recorded by {@code H} as being members
3957 * of its nest, and for which {@code H} can be determined as their nest host,
3958 * are indicated by subsequent elements of the returned array. The order of
3959 * such elements is unspecified. Duplicates are permitted.
3960 *
3961 * <p>If this {@code Class} object represents a primitive type, an array type,
3962 * or {@code void}, then this method returns a single-element array containing
3963 * {@code this}.
3964 *
3965 * @apiNote
3966 * The returned array includes only the nest members recorded in the {@code NestMembers}
3967 * attribute, and not any hidden classes that were added to the nest via
3968 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3969 * Lookup::defineHiddenClass}.
3970 *
3971 * @return an array of all classes and interfaces in the same nest as
3972 * this class or interface
3973 *
3974 * @since 11
3975 * @see #getNestHost()
3976 * @jvms 4.7.28 The {@code NestHost} Attribute
3977 * @jvms 4.7.29 The {@code NestMembers} Attribute
3978 */
3979 public Class<?>[] getNestMembers() {
3980 if (isPrimitive() || isArray()) {
3981 return new Class<?>[] { this };
3982 }
3983 Class<?>[] members = getNestMembers0();
3984 // Can't actually enable this due to bootstrapping issues
3985 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3986 return members;
3987 }
3988
3989 /**
3990 * Returns the descriptor string of the entity (class, interface, array class,
3991 * primitive type, or {@code void}) represented by this {@code Class} object.
3992 *
3993 * <p> If this {@code Class} object represents a class or interface,
3994 * not an array class, then:
3995 * <ul>
3996 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3997 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3998 * for the class or interface. Calling
3999 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
4000 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
4001 * describing this class or interface.
4002 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
4003 * then the result is a string of the form:
4004 * <blockquote>
4005 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
4006 * </blockquote>
4007 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
4008 * encoded in internal form indicated by the {@code class} file passed to
4009 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
4010 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
4011 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
4012 * The result string is not a type descriptor.
4013 * </ul>
4014 *
4015 * <p> If this {@code Class} object represents an array class, then
4016 * the result is a string consisting of one or more '{@code [}' characters
4017 * representing the depth of the array nesting, followed by the
4018 * descriptor string of the element type.
4019 * <ul>
4020 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
4021 * or interface, then this array class can be described nominally.
4022 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
4023 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
4024 * describing this array class.
4025 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
4026 * interface, then this array class cannot be described nominally.
4027 * The result string is not a type descriptor.
4028 * </ul>
4029 *
4030 * <p> If this {@code Class} object represents a primitive type or
4031 * {@code void}, then the result is a field descriptor string which
4032 * is a one-letter code corresponding to a primitive type or {@code void}
4033 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
4034 *
4035 * @return the descriptor string for this {@code Class} object
4036 * @jvms 4.3.2 Field Descriptors
4037 * @since 12
4038 */
4039 @Override
4040 public String descriptorString() {
4041 if (isPrimitive())
4042 return Wrapper.forPrimitiveType(this).basicTypeString();
4043
4044 if (isArray()) {
4045 return "[".concat(componentType.descriptorString());
4046 } else if (isHidden()) {
4047 String name = getName();
4048 int index = name.indexOf('/');
4049 return new StringBuilder(name.length() + 2)
4050 .append('L')
4051 .append(name.substring(0, index).replace('.', '/'))
4052 .append('.')
4053 .append(name, index + 1, name.length())
4054 .append(';')
4055 .toString();
4056 } else {
4057 String name = getName().replace('.', '/');
4058 return StringConcatHelper.concat("L", name, ";");
4059 }
4060 }
4061
4062 /**
4063 * Returns the component type of this {@code Class}, if it describes
4064 * an array type, or {@code null} otherwise.
4065 *
4066 * @implSpec
4067 * Equivalent to {@link Class#getComponentType()}.
4068 *
4069 * @return a {@code Class} describing the component type, or {@code null}
4070 * if this {@code Class} does not describe an array type
4071 * @since 12
4072 */
4073 @Override
4074 public Class<?> componentType() {
4075 return getComponentType();
4076 }
4077
4078 /**
4079 * Returns a {@code Class} for an array type whose component type
4080 * is described by this {@linkplain Class}.
4081 *
4082 * @throws UnsupportedOperationException if this component type is {@linkplain
4083 * Void#TYPE void} or if the number of dimensions of the resulting array
4084 * type would exceed 255.
4085 * @return a {@code Class} describing the array type
4086 * @jvms 4.3.2 Field Descriptors
4087 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4088 * @since 12
4089 */
4090 @Override
4091 public Class<?> arrayType() {
4092 try {
4093 return Array.newInstance(this, 0).getClass();
4094 } catch (IllegalArgumentException iae) {
4095 throw new UnsupportedOperationException(iae);
4096 }
4097 }
4098
4099 /**
4100 * Returns a nominal descriptor for this instance, if one can be
4101 * constructed, or an empty {@link Optional} if one cannot be.
4102 *
4103 * @return An {@link Optional} containing the resulting nominal descriptor,
4104 * or an empty {@link Optional} if one cannot be constructed.
4105 * @since 12
4106 */
4107 @Override
4108 public Optional<ClassDesc> describeConstable() {
4109 Class<?> c = isArray() ? elementType() : this;
4110 return c.isHidden() ? Optional.empty()
4111 : Optional.of(ConstantUtils.classDesc(this));
4112 }
4113
4114 /**
4115 * Returns {@code true} if and only if the underlying class is a hidden class.
4116 *
4117 * @return {@code true} if and only if this class is a hidden class.
4118 *
4119 * @since 15
4120 * @see MethodHandles.Lookup#defineHiddenClass
4121 * @see Class##hiddenClasses Hidden Classes
4122 */
4123 @IntrinsicCandidate
4124 public native boolean isHidden();
4125
4126 /**
4127 * Returns an array containing {@code Class} objects representing the
4128 * direct subinterfaces or subclasses permitted to extend or
4129 * implement this class or interface if it is sealed. The order of such elements
4130 * is unspecified. The array is empty if this sealed class or interface has no
4131 * permitted subclass. If this {@code Class} object represents a primitive type,
4132 * {@code void}, an array type, or a class or interface that is not sealed,
4133 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4134 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4135 * returns a non-null value.
4136 *
4137 * For each class or interface {@code C} which is recorded as a permitted
4138 * direct subinterface or subclass of this class or interface,
4139 * this method attempts to obtain the {@code Class}
4140 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4141 * loader} of the current {@code Class} object).
4142 * The {@code Class} objects which can be obtained and which are direct
4143 * subinterfaces or subclasses of this class or interface,
4144 * are indicated by elements of the returned array. If a {@code Class} object
4145 * cannot be obtained, it is silently ignored, and not included in the result
4146 * array.
4147 *
4148 * @return an array of {@code Class} objects of the permitted subclasses of this class
4149 * or interface, or {@code null} if this class or interface is not sealed.
4150 *
4151 * @jls 8.1 Class Declarations
4152 * @jls 9.1 Interface Declarations
4153 * @since 17
4154 */
4155 public Class<?>[] getPermittedSubclasses() {
4156 Class<?>[] subClasses;
4157 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4158 return null;
4159 }
4160 if (subClasses.length > 0) {
4161 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4162 subClasses = Arrays.stream(subClasses)
4163 .filter(this::isDirectSubType)
4164 .toArray(s -> new Class<?>[s]);
4165 }
4166 }
4167 return subClasses;
4168 }
4169
4170 private boolean isDirectSubType(Class<?> c) {
4171 if (isInterface()) {
4172 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4173 if (i == this) {
4174 return true;
4175 }
4176 }
4177 } else {
4178 return c.getSuperclass() == this;
4179 }
4180 return false;
4181 }
4182
4183 /**
4184 * Returns {@code true} if and only if this {@code Class} object represents
4185 * a sealed class or interface. If this {@code Class} object represents a
4186 * primitive type, {@code void}, or an array type, this method returns
4187 * {@code false}. A sealed class or interface has (possibly zero) permitted
4188 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4189 * possibly empty value for a sealed class or interface.
4190 *
4191 * @return {@code true} if and only if this {@code Class} object represents
4192 * a sealed class or interface.
4193 *
4194 * @jls 8.1 Class Declarations
4195 * @jls 9.1 Interface Declarations
4196 * @since 17
4197 */
4198 public boolean isSealed() {
4199 if (isArray() || isPrimitive()) {
4200 return false;
4201 }
4202 return getPermittedSubclasses() != null;
4203 }
4204
4205 private native Class<?>[] getPermittedSubclasses0();
4206
4207 /*
4208 * Return the class's major and minor class file version packed into an int.
4209 * The high order 16 bits contain the class's minor version. The low order
4210 * 16 bits contain the class's major version.
4211 *
4212 * If the class is an array type then the class file version of its element
4213 * type is returned. If the class is a primitive type then the latest class
4214 * file major version is returned and zero is returned for the minor version.
4215 */
4216 /* package-private */
4217 int getClassFileVersion() {
4218 Class<?> c = isArray() ? elementType() : this;
4219 return c.getClassFileVersion0();
4220 }
4221
4222 private native int getClassFileVersion0();
4223
4224 /**
4225 * Return the access flags as they were in the class's bytecode, including
4226 * the original setting of ACC_SUPER.
4227 *
4228 * If this {@code Class} object represents a primitive type or
4229 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
4230 * {@code FINAL}.
4231 * If this {@code Class} object represents an array type, return 0.
4232 */
4233 int getClassFileAccessFlags() {
4234 return classFileAccessFlags;
4235 }
4236
4237 // Validates the length of the class name and throws an exception if it exceeds the maximum allowed length.
4238 private static void validateClassNameLength(String name) throws ClassNotFoundException {
4239 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
4240 throw new ClassNotFoundException(
4241 "Class name length exceeds limit of "
4242 + ModifiedUtf.CONSTANT_POOL_UTF8_MAX_BYTES
4243 + ": " + name.substring(0,256) + "...");
4244 }
4245 }
4246 }