1 /*
2 * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.constant.ClassDesc;
30 import java.lang.constant.ConstantDescs;
31 import java.lang.invoke.TypeDescriptor;
32 import java.lang.invoke.MethodHandles;
33 import java.lang.ref.SoftReference;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.ObjectStreamField;
37 import java.lang.reflect.AnnotatedElement;
38 import java.lang.reflect.AnnotatedType;
39 import java.lang.reflect.AccessFlag;
40 import java.lang.reflect.Array;
41 import java.lang.reflect.Constructor;
42 import java.lang.reflect.Executable;
43 import java.lang.reflect.Field;
44 import java.lang.reflect.GenericArrayType;
45 import java.lang.reflect.GenericDeclaration;
46 import java.lang.reflect.InvocationTargetException;
47 import java.lang.reflect.Member;
48 import java.lang.reflect.Method;
49 import java.lang.reflect.Modifier;
50 import java.lang.reflect.Proxy;
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.LinkedHashMap;
64 import java.util.LinkedHashSet;
65 import java.util.List;
66 import java.util.Map;
67 import java.util.Objects;
68 import java.util.Optional;
69 import java.util.Set;
70 import java.util.stream.Collectors;
71
72 import jdk.internal.constant.ConstantUtils;
73 import jdk.internal.loader.BootLoader;
74 import jdk.internal.loader.BuiltinClassLoader;
75 import jdk.internal.misc.Unsafe;
76 import jdk.internal.module.Resources;
77 import jdk.internal.reflect.CallerSensitive;
78 import jdk.internal.reflect.CallerSensitiveAdapter;
79 import jdk.internal.reflect.ConstantPool;
80 import jdk.internal.reflect.Reflection;
81 import jdk.internal.reflect.ReflectionFactory;
82 import jdk.internal.vm.annotation.IntrinsicCandidate;
83 import jdk.internal.vm.annotation.Stable;
84
85 import sun.invoke.util.Wrapper;
86 import sun.reflect.generics.factory.CoreReflectionFactory;
87 import sun.reflect.generics.factory.GenericsFactory;
88 import sun.reflect.generics.repository.ClassRepository;
89 import sun.reflect.generics.repository.MethodRepository;
90 import sun.reflect.generics.repository.ConstructorRepository;
91 import sun.reflect.generics.scope.ClassScope;
92 import sun.reflect.annotation.*;
93
94 /**
95 * Instances of the class {@code Class} represent classes and
96 * interfaces in a running Java application. An enum class and a record
97 * class are kinds of class; an annotation interface is a kind of
98 * interface. Every array also belongs to a class that is reflected as
99 * a {@code Class} object that is shared by all arrays with the same
100 * element type and number of dimensions. The primitive Java types
101 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
102 * int}, {@code long}, {@code float}, and {@code double}), and the
103 * keyword {@code void} are also represented as {@code Class} objects.
104 *
105 * <p> {@code Class} has no public constructor. Instead a {@code Class}
106 * object is constructed automatically by the Java Virtual Machine when
107 * a class is derived from the bytes of a {@code class} file through
108 * the invocation of one of the following methods:
109 * <ul>
110 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
111 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
112 * java.lang.invoke.MethodHandles.Lookup::defineClass}
113 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
114 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
115 * </ul>
116 *
117 * <p> The methods of class {@code Class} expose many characteristics of a
118 * class or interface. Most characteristics are derived from the {@code class}
119 * file that the class loader passed to the Java Virtual Machine or
120 * from the {@code class} file passed to {@code Lookup::defineClass}
121 * or {@code Lookup::defineHiddenClass}.
122 * A few characteristics are determined by the class loading environment
123 * at run time, such as the module returned by {@link #getModule() getModule()}.
124 *
125 * <p> The following example uses a {@code Class} object to print the
126 * class name of an object:
127 *
128 * {@snippet lang="java" :
129 * void printClassName(Object obj) {
130 * System.out.println("The class of " + obj +
131 * " is " + obj.getClass().getName());
132 * }}
133 *
134 * It is also possible to get the {@code Class} object for a named
135 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
136 * (JLS {@jls 15.8.2}).
137 * For example:
138 *
139 * {@snippet lang="java" :
140 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
141 * }
142 *
143 * <p> Some methods of class {@code Class} expose whether the declaration of
144 * a class or interface in Java source code was <em>enclosed</em> within
145 * another declaration. Other methods describe how a class or interface
146 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
147 * classes and interfaces, in the same run-time package, that
148 * allow mutual access to their {@code private} members.
149 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
150 * (JVMS {@jvms 4.7.29}).
151 * One nestmate acts as the
152 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
153 * belong to the nest; each of them in turn records it as the nest host.
154 * The classes and interfaces which belong to a nest, including its host, are
155 * determined when
156 * {@code class} files are generated, for example, a Java compiler
157 * will typically record a top-level class as the host of a nest where the
158 * other members are the classes and interfaces whose declarations are
159 * enclosed within the top-level class declaration.
160 *
161 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
162 * A class or interface created by the invocation of
163 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
164 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
165 * class or interface.
166 * All kinds of class, including enum classes and record classes, may be
167 * hidden classes; all kinds of interface, including annotation interfaces,
168 * may be hidden interfaces.
169 *
170 * The {@linkplain #getName() name of a hidden class or interface} is
171 * not a {@linkplain ClassLoader##binary-name binary name},
172 * which means the following:
173 * <ul>
174 * <li>A hidden class or interface cannot be referenced by the constant pools
175 * of other classes and interfaces.
176 * <li>A hidden class or interface cannot be described in
177 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
178 * {@link #describeConstable() Class::describeConstable},
179 * {@link ClassDesc#of(String) ClassDesc::of}, or
180 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
181 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
182 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
183 * </ul>
184 *
185 * A hidden class or interface is never an array class, but may be
186 * the element type of an array. In all other respects, the fact that
187 * a class or interface is hidden has no bearing on the characteristics
188 * exposed by the methods of class {@code Class}.
189 *
190 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
191 *
192 * Conventionally, a Java compiler, starting from a source file for an
193 * implicitly declared class, say {@code HelloWorld.java}, creates a
194 * similarly-named {@code class} file, {@code HelloWorld.class}, where
195 * the class stored in that {@code class} file is named {@code
196 * "HelloWorld"}, matching the base names of the source and {@code
197 * class} files.
198 *
199 * For the {@code Class} object of an implicitly declared class {@code
200 * HelloWorld}, the methods to get the {@linkplain #getName name} and
201 * {@linkplain #getTypeName type name} return results
202 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
203 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
204 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
205 *
206 * @param <T> the type of the class modeled by this {@code Class}
207 * object. For example, the type of {@code String.class} is {@code
208 * Class<String>}. Use {@code Class<?>} if the class being modeled is
209 * unknown.
210 *
211 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
212 * @since 1.0
213 */
214 public final class Class<T> implements java.io.Serializable,
215 GenericDeclaration,
216 Type,
217 AnnotatedElement,
218 TypeDescriptor.OfField<Class<?>>,
219 Constable {
220 private static final int ANNOTATION= 0x00002000;
221 private static final int ENUM = 0x00004000;
222 private static final int SYNTHETIC = 0x00001000;
223
224 private static native void registerNatives();
225 static {
226 runtimeSetup();
227 }
228
229 // Called from JVM when loading an AOT cache
230 private static void runtimeSetup() {
231 registerNatives();
232 }
233
234 /*
235 * Private constructor. Only the Java Virtual Machine creates Class objects.
236 * This constructor is not used and prevents the default constructor being
237 * generated.
238 */
239 private Class(ClassLoader loader, Class<?> arrayComponentType) {
240 // Initialize final field for classLoader. The initialization value of non-null
241 // prevents future JIT optimizations from assuming this final field is null.
242 classLoader = loader;
243 componentType = arrayComponentType;
244 }
245
246 /**
247 * Converts the object to a string. The string representation is the
248 * string "class" or "interface", followed by a space, and then by the
249 * name of the class in the format returned by {@code getName}.
250 * If this {@code Class} object represents a primitive type,
251 * this method returns the name of the primitive type. If
252 * this {@code Class} object represents void this method returns
253 * "void". If this {@code Class} object represents an array type,
254 * this method returns "class " followed by {@code getName}.
255 *
256 * @return a string representation of this {@code Class} object.
257 */
258 public String toString() {
259 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
260 return kind.concat(getName());
261 }
262
263 /**
264 * Returns a string describing this {@code Class}, including
265 * information about modifiers, {@link #isSealed() sealed}/{@code
266 * non-sealed} status, and type parameters.
267 *
268 * The string is formatted as a list of type modifiers, if any,
269 * followed by the kind of type (empty string for primitive types
270 * and {@code class}, {@code enum}, {@code interface},
271 * {@code @interface}, or {@code record} as appropriate), followed
272 * by the type's name, followed by an angle-bracketed
273 * comma-separated list of the type's type parameters, if any,
274 * including informative bounds on the type parameters, if any.
275 *
276 * A space is used to separate modifiers from one another and to
277 * separate any modifiers from the kind of type. The modifiers
278 * occur in canonical order. If there are no type parameters, the
279 * type parameter list is elided.
280 *
281 * For an array type, the string starts with the type name,
282 * followed by an angle-bracketed comma-separated list of the
283 * type's type parameters, if any, followed by a sequence of
284 * {@code []} characters, one set of brackets per dimension of
285 * the array.
286 *
287 * <p>Note that since information about the runtime representation
288 * of a type is being generated, modifiers not present on the
289 * originating source code or illegal on the originating source
290 * code may be present.
291 *
292 * @return a string describing this {@code Class}, including
293 * information about modifiers and type parameters
294 *
295 * @since 1.8
296 */
297 public String toGenericString() {
298 if (isPrimitive()) {
299 return toString();
300 } else {
301 StringBuilder sb = new StringBuilder();
302 Class<?> component = this;
303 int arrayDepth = 0;
304
305 if (isArray()) {
306 do {
307 arrayDepth++;
308 component = component.getComponentType();
309 } while (component.isArray());
310 sb.append(component.getName());
311 } else {
312 // Class modifiers are a superset of interface modifiers
313 int modifiers = getModifiers() & Modifier.classModifiers();
314 if (modifiers != 0) {
315 sb.append(Modifier.toString(modifiers));
316 sb.append(' ');
317 }
318
319 // A class cannot be strictfp and sealed/non-sealed so
320 // it is sufficient to check for sealed-ness after all
321 // modifiers are printed.
322 addSealingInfo(modifiers, sb);
323
324 if (isAnnotation()) {
325 sb.append('@');
326 }
327 if (isInterface()) { // Note: all annotation interfaces are interfaces
328 sb.append("interface");
329 } else {
330 if (isEnum())
331 sb.append("enum");
332 else if (isRecord())
333 sb.append("record");
334 else
335 sb.append("class");
336 }
337 sb.append(' ');
338 sb.append(getName());
339 }
340
341 TypeVariable<?>[] typeparms = component.getTypeParameters();
342 if (typeparms.length > 0) {
343 sb.append(Arrays.stream(typeparms)
344 .map(Class::typeVarBounds)
345 .collect(Collectors.joining(",", "<", ">")));
346 }
347
348 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
349
350 return sb.toString();
351 }
352 }
353
354 private void addSealingInfo(int modifiers, StringBuilder sb) {
355 // A class can be final XOR sealed XOR non-sealed.
356 if (Modifier.isFinal(modifiers)) {
357 return; // no-op
358 } else {
359 if (isSealed()) {
360 sb.append("sealed ");
361 return;
362 } else {
363 // Check for sealed ancestor, which implies this class
364 // is non-sealed.
365 if (hasSealedAncestor(this)) {
366 sb.append("non-sealed ");
367 }
368 }
369 }
370 }
371
372 private boolean hasSealedAncestor(Class<?> clazz) {
373 // From JLS 8.1.1.2:
374 // "It is a compile-time error if a class has a sealed direct
375 // superclass or a sealed direct superinterface, and is not
376 // declared final, sealed, or non-sealed either explicitly or
377 // implicitly.
378 // Thus, an effect of the sealed keyword is to force all
379 // direct subclasses to explicitly declare whether they are
380 // final, sealed, or non-sealed. This avoids accidentally
381 // exposing a sealed class hierarchy to unwanted subclassing."
382
383 // Therefore, will just check direct superclass and
384 // superinterfaces.
385 var superclass = clazz.getSuperclass();
386 if (superclass != null && superclass.isSealed()) {
387 return true;
388 }
389 for (var superinterface : clazz.getInterfaces()) {
390 if (superinterface.isSealed()) {
391 return true;
392 }
393 }
394 return false;
395 }
396
397 static String typeVarBounds(TypeVariable<?> typeVar) {
398 Type[] bounds = typeVar.getBounds();
399 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
400 return typeVar.getName();
401 } else {
402 return typeVar.getName() + " extends " +
403 Arrays.stream(bounds)
404 .map(Type::getTypeName)
405 .collect(Collectors.joining(" & "));
406 }
407 }
408
409 /**
410 * Returns the {@code Class} object associated with the class or
411 * interface with the given string name. Invoking this method is
412 * equivalent to:
413 *
414 * {@snippet lang="java" :
415 * Class.forName(className, true, currentLoader)
416 * }
417 *
418 * where {@code currentLoader} denotes the defining class loader of
419 * the current class.
420 *
421 * <p> For example, the following code fragment returns the
422 * runtime {@code Class} object for the class named
423 * {@code java.lang.Thread}:
424 *
425 * {@snippet lang="java" :
426 * Class<?> t = Class.forName("java.lang.Thread");
427 * }
428 * <p>
429 * A call to {@code forName("X")} causes the class named
430 * {@code X} to be initialized.
431 *
432 * <p>
433 * In cases where this method is called from a context where there is no
434 * caller frame on the stack (e.g. when called directly from a JNI
435 * attached thread), the system class loader is used.
436 *
437 * @param className the {@linkplain ClassLoader##binary-name binary name}
438 * of the class or the string representing an array type
439 * @return the {@code Class} object for the class with the
440 * specified name.
441 * @throws LinkageError if the linkage fails
442 * @throws ExceptionInInitializerError if the initialization provoked
443 * by this method fails
444 * @throws ClassNotFoundException if the class cannot be located
445 *
446 * @jls 12.2 Loading of Classes and Interfaces
447 * @jls 12.3 Linking of Classes and Interfaces
448 * @jls 12.4 Initialization of Classes and Interfaces
449 */
450 @CallerSensitive
451 public static Class<?> forName(String className)
452 throws ClassNotFoundException {
453 Class<?> caller = Reflection.getCallerClass();
454 return forName(className, caller);
455 }
456
457 // Caller-sensitive adapter method for reflective invocation
458 @CallerSensitiveAdapter
459 private static Class<?> forName(String className, Class<?> caller)
460 throws ClassNotFoundException {
461 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
462 : ClassLoader.getClassLoader(caller);
463 return forName0(className, true, loader, caller);
464 }
465
466 /**
467 * Returns the {@code Class} object associated with the class or
468 * interface with the given string name, using the given class loader.
469 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
470 * this method attempts to locate and load the class or interface. The specified
471 * class loader is used to load the class or interface. If the parameter
472 * {@code loader} is {@code null}, the class is loaded through the bootstrap
473 * class loader. The class is initialized only if the
474 * {@code initialize} parameter is {@code true} and if it has
475 * not been initialized earlier.
476 *
477 * <p> This method cannot be used to obtain any of the {@code Class} objects
478 * representing primitive types or void, hidden classes or interfaces,
479 * or array classes whose element type is a hidden class or interface.
480 * If {@code name} denotes a primitive type or void, for example {@code I},
481 * an attempt will be made to locate a user-defined class in the unnamed package
482 * whose name is {@code I} instead.
483 * To obtain a {@code Class} object for a named primitive type
484 * such as {@code int} or {@code long} use {@link
485 * #forPrimitiveName(String)}.
486 *
487 * <p> To obtain the {@code Class} object associated with an array class,
488 * the name consists of one or more {@code '['} representing the depth
489 * of the array nesting, followed by the element type as encoded in
490 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
491 *
492 * <p> Examples:
493 * {@snippet lang="java" :
494 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
495 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
496 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
497 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
498 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
499 * }
500 *
501 * <p> A call to {@code getName()} on the {@code Class} object returned
502 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
503 *
504 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
505 * named <i>N</i> to be loaded but not initialized regardless of the value
506 * of the {@code initialize} parameter.
507 *
508 * @apiNote
509 * This method throws errors related to loading, linking or initializing
510 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
511 * <cite>The Java Language Specification</cite>.
512 * In addition, this method does not check whether the requested class
513 * is accessible to its caller.
514 *
515 * @param name the {@linkplain ClassLoader##binary-name binary name}
516 * of the class or the string representing an array class
517 *
518 * @param initialize if {@code true} the class will be initialized
519 * (which implies linking). See Section {@jls
520 * 12.4} of <cite>The Java Language
521 * Specification</cite>.
522 * @param loader class loader from which the class must be loaded
523 * @return class object representing the desired class
524 *
525 * @throws LinkageError if the linkage fails
526 * @throws ExceptionInInitializerError if the initialization provoked
527 * by this method fails
528 * @throws ClassNotFoundException if the class cannot be located by
529 * the specified class loader
530 *
531 * @see java.lang.Class#forName(String)
532 * @see java.lang.ClassLoader
533 *
534 * @jls 12.2 Loading of Classes and Interfaces
535 * @jls 12.3 Linking of Classes and Interfaces
536 * @jls 12.4 Initialization of Classes and Interfaces
537 * @jls 13.1 The Form of a Binary
538 * @since 1.2
539 */
540 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
541 throws ClassNotFoundException
542 {
543 return forName0(name, initialize, loader, null);
544 }
545
546 /** Called after security check for system loader access checks have been made. */
547 private static native Class<?> forName0(String name, boolean initialize,
548 ClassLoader loader,
549 Class<?> caller)
550 throws ClassNotFoundException;
551
552
553 /**
554 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
555 * binary name} in the given module.
556 *
557 * <p> This method attempts to locate and load the class or interface.
558 * It does not link the class, and does not run the class initializer.
559 * If the class is not found, this method returns {@code null}. </p>
560 *
561 * <p> If the class loader of the given module defines other modules and
562 * the given name is a class defined in a different module, this method
563 * returns {@code null} after the class is loaded. </p>
564 *
565 * <p> This method does not check whether the requested class is
566 * accessible to its caller. </p>
567 *
568 * @apiNote
569 * This method does not support loading of array types, unlike
570 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
571 * a binary name. This method returns {@code null} on failure rather than
572 * throwing a {@link ClassNotFoundException}, as is done by
573 * the {@link #forName(String, boolean, ClassLoader)} method.
574 *
575 * @param module A module
576 * @param name The {@linkplain ClassLoader##binary-name binary name}
577 * of the class
578 * @return {@code Class} object of the given name defined in the given module;
579 * {@code null} if not found.
580 *
581 * @throws NullPointerException if the given module or name is {@code null}
582 *
583 * @throws LinkageError if the linkage fails
584 *
585 * @jls 12.2 Loading of Classes and Interfaces
586 * @jls 12.3 Linking of Classes and Interfaces
587 * @since 9
588 */
589 public static Class<?> forName(Module module, String name) {
590 Objects.requireNonNull(module);
591 Objects.requireNonNull(name);
592
593 ClassLoader cl = module.getClassLoader();
594 if (cl != null) {
595 return cl.loadClass(module, name);
596 } else {
597 return BootLoader.loadClass(module, name);
598 }
599 }
600
601 /**
602 * {@return the {@code Class} object associated with the
603 * {@linkplain #isPrimitive() primitive type} of the given name}
604 * If the argument is not the name of a primitive type, {@code
605 * null} is returned.
606 *
607 * @param primitiveName the name of the primitive type to find
608 *
609 * @throws NullPointerException if the argument is {@code null}
610 *
611 * @jls 4.2 Primitive Types and Values
612 * @jls 15.8.2 Class Literals
613 * @since 22
614 */
615 public static Class<?> forPrimitiveName(String primitiveName) {
616 return switch(primitiveName) {
617 // Integral types
618 case "int" -> int.class;
619 case "long" -> long.class;
620 case "short" -> short.class;
621 case "char" -> char.class;
622 case "byte" -> byte.class;
623
624 // Floating-point types
625 case "float" -> float.class;
626 case "double" -> double.class;
627
628 // Other types
629 case "boolean" -> boolean.class;
630 case "void" -> void.class;
631
632 default -> null;
633 };
634 }
635
636 /**
637 * Creates a new instance of the class represented by this {@code Class}
638 * object. The class is instantiated as if by a {@code new}
639 * expression with an empty argument list. The class is initialized if it
640 * has not already been initialized.
641 *
642 * @deprecated This method propagates any exception thrown by the
643 * nullary constructor, including a checked exception. Use of
644 * this method effectively bypasses the compile-time exception
645 * checking that would otherwise be performed by the compiler.
646 * The {@link
647 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
648 * Constructor.newInstance} method avoids this problem by wrapping
649 * any exception thrown by the constructor in a (checked) {@link
650 * java.lang.reflect.InvocationTargetException}.
651 *
652 * <p>The call
653 *
654 * {@snippet lang="java" :
655 * clazz.newInstance()
656 * }
657 *
658 * can be replaced by
659 *
660 * {@snippet lang="java" :
661 * clazz.getDeclaredConstructor().newInstance()
662 * }
663 *
664 * The latter sequence of calls is inferred to be able to throw
665 * the additional exception types {@link
666 * InvocationTargetException} and {@link
667 * NoSuchMethodException}. Both of these exception types are
668 * subclasses of {@link ReflectiveOperationException}.
669 *
670 * @return a newly allocated instance of the class represented by this
671 * object.
672 * @throws IllegalAccessException if the class or its nullary
673 * constructor is not accessible.
674 * @throws InstantiationException
675 * if this {@code Class} represents an abstract class,
676 * an interface, an array class, a primitive type, or void;
677 * or if the class has no nullary constructor;
678 * or if the instantiation fails for some other reason.
679 * @throws ExceptionInInitializerError if the initialization
680 * provoked by this method fails.
681 */
682 @CallerSensitive
683 @Deprecated(since="9")
684 public T newInstance()
685 throws InstantiationException, IllegalAccessException
686 {
687 // Constructor lookup
688 Constructor<T> tmpConstructor = cachedConstructor;
689 if (tmpConstructor == null) {
690 if (this == Class.class) {
691 throw new IllegalAccessException(
692 "Can not call newInstance() on the Class for java.lang.Class"
693 );
694 }
695 try {
696 Class<?>[] empty = {};
697 final Constructor<T> c = getReflectionFactory().copyConstructor(
698 getConstructor0(empty, Member.DECLARED));
699 // Disable accessibility checks on the constructor
700 // access check is done with the true caller
701 c.setAccessible(true);
702 cachedConstructor = tmpConstructor = c;
703 } catch (NoSuchMethodException e) {
704 throw (InstantiationException)
705 new InstantiationException(getName()).initCause(e);
706 }
707 }
708
709 try {
710 Class<?> caller = Reflection.getCallerClass();
711 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
712 } catch (InvocationTargetException e) {
713 Unsafe.getUnsafe().throwException(e.getTargetException());
714 // Not reached
715 return null;
716 }
717 }
718
719 private transient volatile Constructor<T> cachedConstructor;
720
721 /**
722 * Determines if the specified {@code Object} is assignment-compatible
723 * with the object represented by this {@code Class}. This method is
724 * the dynamic equivalent of the Java language {@code instanceof}
725 * operator. The method returns {@code true} if the specified
726 * {@code Object} argument is non-null and can be cast to the
727 * reference type represented by this {@code Class} object without
728 * raising a {@code ClassCastException.} It returns {@code false}
729 * otherwise.
730 *
731 * <p> Specifically, if this {@code Class} object represents a
732 * declared class, this method returns {@code true} if the specified
733 * {@code Object} argument is an instance of the represented class (or
734 * of any of its subclasses); it returns {@code false} otherwise. If
735 * this {@code Class} object represents an array class, this method
736 * returns {@code true} if the specified {@code Object} argument
737 * can be converted to an object of the array class by an identity
738 * conversion or by a widening reference conversion; it returns
739 * {@code false} otherwise. If this {@code Class} object
740 * represents an interface, this method returns {@code true} if the
741 * class or any superclass of the specified {@code Object} argument
742 * implements this interface; it returns {@code false} otherwise. If
743 * this {@code Class} object represents a primitive type, this method
744 * returns {@code false}.
745 *
746 * @param obj the object to check
747 * @return true if {@code obj} is an instance of this class
748 *
749 * @since 1.1
750 */
751 @IntrinsicCandidate
752 public native boolean isInstance(Object obj);
753
754
755 /**
756 * Determines if the class or interface represented by this
757 * {@code Class} object is either the same as, or is a superclass or
758 * superinterface of, the class or interface represented by the specified
759 * {@code Class} parameter. It returns {@code true} if so;
760 * otherwise it returns {@code false}. If this {@code Class}
761 * object represents a primitive type, this method returns
762 * {@code true} if the specified {@code Class} parameter is
763 * exactly this {@code Class} object; otherwise it returns
764 * {@code false}.
765 *
766 * <p> Specifically, this method tests whether the type represented by the
767 * specified {@code Class} parameter can be converted to the type
768 * represented by this {@code Class} object via an identity conversion
769 * or via a widening reference conversion. See <cite>The Java Language
770 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
771 * for details.
772 *
773 * @param cls the {@code Class} object to be checked
774 * @return the {@code boolean} value indicating whether objects of the
775 * type {@code cls} can be assigned to objects of this class
776 * @throws NullPointerException if the specified Class parameter is
777 * null.
778 * @since 1.1
779 */
780 @IntrinsicCandidate
781 public native boolean isAssignableFrom(Class<?> cls);
782
783
784 /**
785 * Determines if this {@code Class} object represents an
786 * interface type.
787 *
788 * @return {@code true} if this {@code Class} object represents an interface;
789 * {@code false} otherwise.
790 */
791 @IntrinsicCandidate
792 public native boolean isInterface();
793
794
795 /**
796 * Determines if this {@code Class} object represents an array class.
797 *
798 * @return {@code true} if this {@code Class} object represents an array class;
799 * {@code false} otherwise.
800 * @since 1.1
801 */
802 @IntrinsicCandidate
803 public native boolean isArray();
804
805
806 /**
807 * Determines if this {@code Class} object represents a primitive
808 * type or void.
809 *
810 * <p> There are nine predefined {@code Class} objects to
811 * represent the eight primitive types and void. These are
812 * created by the Java Virtual Machine, and have the same
813 * {@linkplain #getName() names} as the primitive types that they
814 * represent, namely {@code boolean}, {@code byte}, {@code char},
815 * {@code short}, {@code int}, {@code long}, {@code float}, and
816 * {@code double}.
817 *
818 * <p>No other class objects are considered primitive.
819 *
820 * @apiNote
821 * A {@code Class} object represented by a primitive type can be
822 * accessed via the {@code TYPE} public static final variables
823 * defined in the primitive wrapper classes such as {@link
824 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
825 * language, the objects may be referred to by a class literal
826 * expression such as {@code int.class}. The {@code Class} object
827 * for void can be expressed as {@code void.class} or {@link
828 * java.lang.Void#TYPE Void.TYPE}.
829 *
830 * @return true if and only if this class represents a primitive type
831 *
832 * @see java.lang.Boolean#TYPE
833 * @see java.lang.Character#TYPE
834 * @see java.lang.Byte#TYPE
835 * @see java.lang.Short#TYPE
836 * @see java.lang.Integer#TYPE
837 * @see java.lang.Long#TYPE
838 * @see java.lang.Float#TYPE
839 * @see java.lang.Double#TYPE
840 * @see java.lang.Void#TYPE
841 * @since 1.1
842 * @jls 15.8.2 Class Literals
843 */
844 @IntrinsicCandidate
845 public native boolean isPrimitive();
846
847 /**
848 * Returns true if this {@code Class} object represents an annotation
849 * interface. Note that if this method returns true, {@link #isInterface()}
850 * would also return true, as all annotation interfaces are also interfaces.
851 *
852 * @return {@code true} if this {@code Class} object represents an annotation
853 * interface; {@code false} otherwise
854 * @since 1.5
855 */
856 public boolean isAnnotation() {
857 return (getModifiers() & ANNOTATION) != 0;
858 }
859
860 /**
861 *{@return {@code true} if and only if this class has the synthetic modifier
862 * bit set}
863 *
864 * @jls 13.1 The Form of a Binary
865 * @jvms 4.1 The {@code ClassFile} Structure
866 * @see <a
867 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
868 * programming language and JVM modeling in core reflection</a>
869 * @since 1.5
870 */
871 public boolean isSynthetic() {
872 return (getModifiers() & SYNTHETIC) != 0;
873 }
874
875 /**
876 * Returns the name of the entity (class, interface, array class,
877 * primitive type, or void) represented by this {@code Class} object.
878 *
879 * <p> If this {@code Class} object represents a class or interface,
880 * not an array class, then:
881 * <ul>
882 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
883 * then the {@linkplain ClassLoader##binary-name binary name}
884 * of the class or interface is returned.
885 * <li> If the class or interface is hidden, then the result is a string
886 * of the form: {@code N + '/' + <suffix>}
887 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
888 * indicated by the {@code class} file passed to
889 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
890 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
891 * </ul>
892 *
893 * <p> If this {@code Class} object represents an array class, then
894 * the result is a string consisting of one or more '{@code [}' characters
895 * representing the depth of the array nesting, followed by the element
896 * type as encoded using the following table:
897 *
898 * <blockquote><table class="striped" id="nameFormat">
899 * <caption style="display:none">Element types and encodings</caption>
900 * <thead>
901 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
902 * </thead>
903 * <tbody style="text-align:left">
904 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
905 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
906 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
907 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
908 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
909 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
910 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
911 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
912 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
913 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
914 * </tbody>
915 * </table></blockquote>
916 *
917 * <p> If this {@code Class} object represents a primitive type or {@code void},
918 * then the result is a string with the same spelling as the Java language
919 * keyword which corresponds to the primitive type or {@code void}.
920 *
921 * <p> Examples:
922 * <blockquote><pre>
923 * String.class.getName()
924 * returns "java.lang.String"
925 * Character.UnicodeBlock.class.getName()
926 * returns "java.lang.Character$UnicodeBlock"
927 * byte.class.getName()
928 * returns "byte"
929 * (new Object[3]).getClass().getName()
930 * returns "[Ljava.lang.Object;"
931 * (new int[3][4][5][6][7][8][9]).getClass().getName()
932 * returns "[[[[[[[I"
933 * </pre></blockquote>
934 *
935 * @apiNote
936 * Distinct class objects can have the same name but different class loaders.
937 *
938 * @return the name of the class, interface, or other entity
939 * represented by this {@code Class} object.
940 * @jls 13.1 The Form of a Binary
941 */
942 public String getName() {
943 String name = this.name;
944 return name != null ? name : initClassName();
945 }
946
947 // Cache the name to reduce the number of calls into the VM.
948 // This field would be set by VM itself during initClassName call.
949 private transient String name;
950 private native String initClassName();
951
952 /**
953 * Returns the class loader for the class. Some implementations may use
954 * null to represent the bootstrap class loader. This method will return
955 * null in such implementations if this class was loaded by the bootstrap
956 * class loader.
957 *
958 * <p>If this {@code Class} object
959 * represents a primitive type or void, null is returned.
960 *
961 * @return the class loader that loaded the class or interface
962 * represented by this {@code Class} object.
963 * @see java.lang.ClassLoader
964 */
965 public ClassLoader getClassLoader() {
966 return classLoader;
967 }
968
969 // Package-private to allow ClassLoader access
970 ClassLoader getClassLoader0() { return classLoader; }
971
972 /**
973 * Returns the module that this class or interface is a member of.
974 *
975 * If this class represents an array type then this method returns the
976 * {@code Module} for the element type. If this class represents a
977 * primitive type or void, then the {@code Module} object for the
978 * {@code java.base} module is returned.
979 *
980 * If this class is in an unnamed module then the {@linkplain
981 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
982 * loader for this class is returned.
983 *
984 * @return the module that this class or interface is a member of
985 *
986 * @since 9
987 */
988 public Module getModule() {
989 return module;
990 }
991
992 // set by VM
993 @Stable
994 private transient Module module;
995
996 // Initialized in JVM not by private constructor
997 // This field is filtered from reflection access, i.e. getDeclaredField
998 // will throw NoSuchFieldException
999 private final ClassLoader classLoader;
1000
1001 private transient Object classData; // Set by VM
1002 private transient Object[] signers; // Read by VM, mutable
1003
1004 // package-private
1005 Object getClassData() {
1006 return classData;
1007 }
1008
1009 /**
1010 * Returns an array of {@code TypeVariable} objects that represent the
1011 * type variables declared by the generic declaration represented by this
1012 * {@code GenericDeclaration} object, in declaration order. Returns an
1013 * array of length 0 if the underlying generic declaration declares no type
1014 * variables.
1015 *
1016 * @return an array of {@code TypeVariable} objects that represent
1017 * the type variables declared by this generic declaration
1018 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1019 * signature of this generic declaration does not conform to
1020 * the format specified in section {@jvms 4.7.9} of
1021 * <cite>The Java Virtual Machine Specification</cite>
1022 * @since 1.5
1023 */
1024 @SuppressWarnings("unchecked")
1025 public TypeVariable<Class<T>>[] getTypeParameters() {
1026 ClassRepository info = getGenericInfo();
1027 if (info != null)
1028 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1029 else
1030 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1031 }
1032
1033
1034 /**
1035 * Returns the {@code Class} representing the direct superclass of the
1036 * entity (class, interface, primitive type or void) represented by
1037 * this {@code Class}. If this {@code Class} represents either the
1038 * {@code Object} class, an interface, a primitive type, or void, then
1039 * null is returned. If this {@code Class} object represents an array class
1040 * then the {@code Class} object representing the {@code Object} class is
1041 * returned.
1042 *
1043 * @return the direct superclass of the class represented by this {@code Class} object
1044 */
1045 @IntrinsicCandidate
1046 public native Class<? super T> getSuperclass();
1047
1048
1049 /**
1050 * Returns the {@code Type} representing the direct superclass of
1051 * the entity (class, interface, primitive type or void) represented by
1052 * this {@code Class} object.
1053 *
1054 * <p>If the superclass is a parameterized type, the {@code Type}
1055 * object returned must accurately reflect the actual type
1056 * arguments used in the source code. The parameterized type
1057 * representing the superclass is created if it had not been
1058 * created before. See the declaration of {@link
1059 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1060 * semantics of the creation process for parameterized types. If
1061 * this {@code Class} object represents either the {@code Object}
1062 * class, an interface, a primitive type, or void, then null is
1063 * returned. If this {@code Class} object represents an array class
1064 * then the {@code Class} object representing the {@code Object} class is
1065 * returned.
1066 *
1067 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1068 * class signature does not conform to the format specified in
1069 * section {@jvms 4.7.9} of <cite>The Java Virtual
1070 * Machine Specification</cite>
1071 * @throws TypeNotPresentException if the generic superclass
1072 * refers to a non-existent type declaration
1073 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1074 * generic superclass refers to a parameterized type that cannot be
1075 * instantiated for any reason
1076 * @return the direct superclass of the class represented by this {@code Class} object
1077 * @since 1.5
1078 */
1079 public Type getGenericSuperclass() {
1080 ClassRepository info = getGenericInfo();
1081 if (info == null) {
1082 return getSuperclass();
1083 }
1084
1085 // Historical irregularity:
1086 // Generic signature marks interfaces with superclass = Object
1087 // but this API returns null for interfaces
1088 if (isInterface()) {
1089 return null;
1090 }
1091
1092 return info.getSuperclass();
1093 }
1094
1095 /**
1096 * Gets the package of this class.
1097 *
1098 * <p>If this class represents an array type, a primitive type or void,
1099 * this method returns {@code null}.
1100 *
1101 * @return the package of this class.
1102 */
1103 public Package getPackage() {
1104 if (isPrimitive() || isArray()) {
1105 return null;
1106 }
1107 ClassLoader cl = classLoader;
1108 return cl != null ? cl.definePackage(this)
1109 : BootLoader.definePackage(this);
1110 }
1111
1112 /**
1113 * Returns the fully qualified package name.
1114 *
1115 * <p> If this class is a top level class, then this method returns the fully
1116 * qualified name of the package that the class is a member of, or the
1117 * empty string if the class is in an unnamed package.
1118 *
1119 * <p> If this class is a member class, then this method is equivalent to
1120 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1121 * enclosing class}.
1122 *
1123 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1124 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1125 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1126 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1127 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1128 *
1129 * <p> If this class represents an array type then this method returns the
1130 * package name of the element type. If this class represents a primitive
1131 * type or void then the package name "{@code java.lang}" is returned.
1132 *
1133 * @return the fully qualified package name
1134 *
1135 * @since 9
1136 * @jls 6.7 Fully Qualified Names and Canonical Names
1137 */
1138 public String getPackageName() {
1139 String pn = this.packageName;
1140 if (pn == null) {
1141 Class<?> c = isArray() ? elementType() : this;
1142 if (c.isPrimitive()) {
1143 pn = "java.lang";
1144 } else {
1145 String cn = c.getName();
1146 int dot = cn.lastIndexOf('.');
1147 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1148 }
1149 this.packageName = pn;
1150 }
1151 return pn;
1152 }
1153
1154 // cached package name
1155 private transient String packageName;
1156
1157 /**
1158 * Returns the interfaces directly implemented by the class or interface
1159 * represented by this {@code Class} object.
1160 *
1161 * <p>If this {@code Class} object represents a class, the return value is an array
1162 * containing objects representing all interfaces directly implemented by
1163 * the class. The order of the interface objects in the array corresponds
1164 * to the order of the interface names in the {@code implements} clause of
1165 * the declaration of the class represented by this {@code Class} object. For example,
1166 * given the declaration:
1167 * <blockquote>
1168 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1169 * </blockquote>
1170 * suppose the value of {@code s} is an instance of
1171 * {@code Shimmer}; the value of the expression:
1172 * <blockquote>
1173 * {@code s.getClass().getInterfaces()[0]}
1174 * </blockquote>
1175 * is the {@code Class} object that represents interface
1176 * {@code FloorWax}; and the value of:
1177 * <blockquote>
1178 * {@code s.getClass().getInterfaces()[1]}
1179 * </blockquote>
1180 * is the {@code Class} object that represents interface
1181 * {@code DessertTopping}.
1182 *
1183 * <p>If this {@code Class} object represents an interface, the array contains objects
1184 * representing all interfaces directly extended by the interface. The
1185 * order of the interface objects in the array corresponds to the order of
1186 * the interface names in the {@code extends} clause of the declaration of
1187 * the interface represented by this {@code Class} object.
1188 *
1189 * <p>If this {@code Class} object represents a class or interface that implements no
1190 * interfaces, the method returns an array of length 0.
1191 *
1192 * <p>If this {@code Class} object represents a primitive type or void, the method
1193 * returns an array of length 0.
1194 *
1195 * <p>If this {@code Class} object represents an array type, the
1196 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1197 * returned in that order.
1198 *
1199 * @return an array of interfaces directly implemented by this class
1200 */
1201 public Class<?>[] getInterfaces() {
1202 // defensively copy before handing over to user code
1203 return getInterfaces(true);
1204 }
1205
1206 private Class<?>[] getInterfaces(boolean cloneArray) {
1207 ReflectionData<T> rd = reflectionData();
1208 Class<?>[] interfaces = rd.interfaces;
1209 if (interfaces == null) {
1210 interfaces = getInterfaces0();
1211 rd.interfaces = interfaces;
1212 }
1213 // defensively copy if requested
1214 return cloneArray ? interfaces.clone() : interfaces;
1215 }
1216
1217 private native Class<?>[] getInterfaces0();
1218
1219 /**
1220 * Returns the {@code Type}s representing the interfaces
1221 * directly implemented by the class or interface represented by
1222 * this {@code Class} object.
1223 *
1224 * <p>If a superinterface is a parameterized type, the
1225 * {@code Type} object returned for it must accurately reflect
1226 * the actual type arguments used in the source code. The
1227 * parameterized type representing each superinterface is created
1228 * if it had not been created before. See the declaration of
1229 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1230 * for the semantics of the creation process for parameterized
1231 * types.
1232 *
1233 * <p>If this {@code Class} object represents a class, the return value is an array
1234 * containing objects representing all interfaces directly implemented by
1235 * the class. The order of the interface objects in the array corresponds
1236 * to the order of the interface names in the {@code implements} clause of
1237 * the declaration of the class represented by this {@code Class} object.
1238 *
1239 * <p>If this {@code Class} object represents an interface, the array contains objects
1240 * representing all interfaces directly extended by the interface. The
1241 * order of the interface objects in the array corresponds to the order of
1242 * the interface names in the {@code extends} clause of the declaration of
1243 * the interface represented by this {@code Class} object.
1244 *
1245 * <p>If this {@code Class} object represents a class or interface that implements no
1246 * interfaces, the method returns an array of length 0.
1247 *
1248 * <p>If this {@code Class} object represents a primitive type or void, the method
1249 * returns an array of length 0.
1250 *
1251 * <p>If this {@code Class} object represents an array type, the
1252 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1253 * returned in that order.
1254 *
1255 * @throws java.lang.reflect.GenericSignatureFormatError
1256 * if the generic class signature does not conform to the
1257 * format specified in section {@jvms 4.7.9} of <cite>The
1258 * Java Virtual Machine Specification</cite>
1259 * @throws TypeNotPresentException if any of the generic
1260 * superinterfaces refers to a non-existent type declaration
1261 * @throws java.lang.reflect.MalformedParameterizedTypeException
1262 * if any of the generic superinterfaces refer to a parameterized
1263 * type that cannot be instantiated for any reason
1264 * @return an array of interfaces directly implemented by this class
1265 * @since 1.5
1266 */
1267 public Type[] getGenericInterfaces() {
1268 ClassRepository info = getGenericInfo();
1269 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1270 }
1271
1272
1273 /**
1274 * Returns the {@code Class} representing the component type of an
1275 * array. If this class does not represent an array class this method
1276 * returns null.
1277 *
1278 * @return the {@code Class} representing the component type of this
1279 * class if this class is an array
1280 * @see java.lang.reflect.Array
1281 * @since 1.1
1282 */
1283 public Class<?> getComponentType() {
1284 // Only return for array types. Storage may be reused for Class for instance types.
1285 if (isArray()) {
1286 return componentType;
1287 } else {
1288 return null;
1289 }
1290 }
1291
1292 private final Class<?> componentType;
1293
1294 /*
1295 * Returns the {@code Class} representing the element type of an array class.
1296 * If this class does not represent an array class, then this method returns
1297 * {@code null}.
1298 */
1299 private Class<?> elementType() {
1300 if (!isArray()) return null;
1301
1302 Class<?> c = this;
1303 while (c.isArray()) {
1304 c = c.getComponentType();
1305 }
1306 return c;
1307 }
1308
1309 /**
1310 * Returns the Java language modifiers for this class or interface, encoded
1311 * in an integer. The modifiers consist of the Java Virtual Machine's
1312 * constants for {@code public}, {@code protected},
1313 * {@code private}, {@code final}, {@code static},
1314 * {@code abstract} and {@code interface}; they should be decoded
1315 * using the methods of class {@code Modifier}.
1316 *
1317 * <p> If the underlying class is an array class:
1318 * <ul>
1319 * <li> its {@code public}, {@code private} and {@code protected}
1320 * modifiers are the same as those of its component type
1321 * <li> its {@code abstract} and {@code final} modifiers are always
1322 * {@code true}
1323 * <li> its interface modifier is always {@code false}, even when
1324 * the component type is an interface
1325 * </ul>
1326 * If this {@code Class} object represents a primitive type or
1327 * void, its {@code public}, {@code abstract}, and {@code final}
1328 * modifiers are always {@code true}.
1329 * For {@code Class} objects representing void, primitive types, and
1330 * arrays, the values of other modifiers are {@code false} other
1331 * than as specified above.
1332 *
1333 * <p> The modifier encodings are defined in section {@jvms 4.1}
1334 * of <cite>The Java Virtual Machine Specification</cite>.
1335 *
1336 * @return the {@code int} representing the modifiers for this class
1337 * @see java.lang.reflect.Modifier
1338 * @see #accessFlags()
1339 * @see <a
1340 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1341 * programming language and JVM modeling in core reflection</a>
1342 * @since 1.1
1343 * @jls 8.1.1 Class Modifiers
1344 * @jls 9.1.1 Interface Modifiers
1345 * @jvms 4.1 The {@code ClassFile} Structure
1346 */
1347 @IntrinsicCandidate
1348 public native int getModifiers();
1349
1350 /**
1351 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1352 * flags} for this class, possibly empty}
1353 *
1354 * <p> If the underlying class is an array class:
1355 * <ul>
1356 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1357 * access flags are the same as those of its component type
1358 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1359 * <li> its {@code INTERFACE} flag is absent, even when the
1360 * component type is an interface
1361 * </ul>
1362 * If this {@code Class} object represents a primitive type or
1363 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1364 * {@code FINAL}.
1365 * For {@code Class} objects representing void, primitive types, and
1366 * arrays, access flags are absent other than as specified above.
1367 *
1368 * @see #getModifiers()
1369 * @jvms 4.1 The ClassFile Structure
1370 * @jvms 4.7.6 The InnerClasses Attribute
1371 * @since 20
1372 */
1373 public Set<AccessFlag> accessFlags() {
1374 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1375 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1376 // and STATIC, which are not allowed on Location.CLASS.
1377 // Use getClassAccessFlagsRaw to expose SUPER status.
1378 var location = (isMemberClass() || isLocalClass() ||
1379 isAnonymousClass() || isArray()) ?
1380 AccessFlag.Location.INNER_CLASS :
1381 AccessFlag.Location.CLASS;
1382 return AccessFlag.maskToAccessFlags((location == AccessFlag.Location.CLASS) ?
1383 getClassAccessFlagsRaw() :
1384 getModifiers(),
1385 location);
1386 }
1387
1388 /**
1389 * Gets the signers of this class.
1390 *
1391 * @return the signers of this class, or null if there are no signers. In
1392 * particular, this method returns null if this {@code Class} object represents
1393 * a primitive type or void.
1394 * @since 1.1
1395 */
1396 public Object[] getSigners() {
1397 var signers = this.signers;
1398 return signers == null ? null : signers.clone();
1399 }
1400
1401 /**
1402 * Set the signers of this class.
1403 */
1404 void setSigners(Object[] signers) {
1405 if (!isPrimitive() && !isArray()) {
1406 this.signers = signers;
1407 }
1408 }
1409
1410 /**
1411 * If this {@code Class} object represents a local or anonymous
1412 * class within a method, returns a {@link
1413 * java.lang.reflect.Method Method} object representing the
1414 * immediately enclosing method of the underlying class. Returns
1415 * {@code null} otherwise.
1416 *
1417 * In particular, this method returns {@code null} if the underlying
1418 * class is a local or anonymous class immediately enclosed by a class or
1419 * interface declaration, instance initializer or static initializer.
1420 *
1421 * @return the immediately enclosing method of the underlying class, if
1422 * that class is a local or anonymous class; otherwise {@code null}.
1423 *
1424 * @since 1.5
1425 */
1426 public Method getEnclosingMethod() {
1427 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1428
1429 if (enclosingInfo == null)
1430 return null;
1431 else {
1432 if (!enclosingInfo.isMethod())
1433 return null;
1434
1435 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1436 getFactory());
1437 Class<?> returnType = toClass(typeInfo.getReturnType());
1438 Type [] parameterTypes = typeInfo.getParameterTypes();
1439 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1440
1441 // Convert Types to Classes; returned types *should*
1442 // be class objects since the methodDescriptor's used
1443 // don't have generics information
1444 for(int i = 0; i < parameterClasses.length; i++)
1445 parameterClasses[i] = toClass(parameterTypes[i]);
1446
1447 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1448 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1449
1450 /*
1451 * Loop over all declared methods; match method name,
1452 * number of and type of parameters, *and* return
1453 * type. Matching return type is also necessary
1454 * because of covariant returns, etc.
1455 */
1456 ReflectionFactory fact = getReflectionFactory();
1457 for (Method m : candidates) {
1458 if (m.getName().equals(enclosingInfo.getName()) &&
1459 arrayContentsEq(parameterClasses,
1460 fact.getExecutableSharedParameterTypes(m))) {
1461 // finally, check return type
1462 if (m.getReturnType().equals(returnType)) {
1463 return fact.copyMethod(m);
1464 }
1465 }
1466 }
1467
1468 throw new InternalError("Enclosing method not found");
1469 }
1470 }
1471
1472 private native Object[] getEnclosingMethod0();
1473
1474 private EnclosingMethodInfo getEnclosingMethodInfo() {
1475 Object[] enclosingInfo = getEnclosingMethod0();
1476 if (enclosingInfo == null)
1477 return null;
1478 else {
1479 return new EnclosingMethodInfo(enclosingInfo);
1480 }
1481 }
1482
1483 private static final class EnclosingMethodInfo {
1484 private final Class<?> enclosingClass;
1485 private final String name;
1486 private final String descriptor;
1487
1488 static void validate(Object[] enclosingInfo) {
1489 if (enclosingInfo.length != 3)
1490 throw new InternalError("Malformed enclosing method information");
1491 try {
1492 // The array is expected to have three elements:
1493
1494 // the immediately enclosing class
1495 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1496 assert(enclosingClass != null);
1497
1498 // the immediately enclosing method or constructor's
1499 // name (can be null).
1500 String name = (String)enclosingInfo[1];
1501
1502 // the immediately enclosing method or constructor's
1503 // descriptor (null iff name is).
1504 String descriptor = (String)enclosingInfo[2];
1505 assert((name != null && descriptor != null) || name == descriptor);
1506 } catch (ClassCastException cce) {
1507 throw new InternalError("Invalid type in enclosing method information", cce);
1508 }
1509 }
1510
1511 EnclosingMethodInfo(Object[] enclosingInfo) {
1512 validate(enclosingInfo);
1513 this.enclosingClass = (Class<?>)enclosingInfo[0];
1514 this.name = (String)enclosingInfo[1];
1515 this.descriptor = (String)enclosingInfo[2];
1516 }
1517
1518 boolean isPartial() {
1519 return enclosingClass == null || name == null || descriptor == null;
1520 }
1521
1522 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1523
1524 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1525
1526 Class<?> getEnclosingClass() { return enclosingClass; }
1527
1528 String getName() { return name; }
1529
1530 String getDescriptor() { return descriptor; }
1531
1532 }
1533
1534 private static Class<?> toClass(Type o) {
1535 if (o instanceof GenericArrayType gat)
1536 return toClass(gat.getGenericComponentType()).arrayType();
1537 return (Class<?>)o;
1538 }
1539
1540 /**
1541 * If this {@code Class} object represents a local or anonymous
1542 * class within a constructor, returns a {@link
1543 * java.lang.reflect.Constructor Constructor} object representing
1544 * the immediately enclosing constructor of the underlying
1545 * class. Returns {@code null} otherwise. In particular, this
1546 * method returns {@code null} if the underlying class is a local
1547 * or anonymous class immediately enclosed by a class or
1548 * interface declaration, instance initializer or static initializer.
1549 *
1550 * @return the immediately enclosing constructor of the underlying class, if
1551 * that class is a local or anonymous class; otherwise {@code null}.
1552 *
1553 * @since 1.5
1554 */
1555 public Constructor<?> getEnclosingConstructor() {
1556 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1557
1558 if (enclosingInfo == null)
1559 return null;
1560 else {
1561 if (!enclosingInfo.isConstructor())
1562 return null;
1563
1564 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1565 getFactory());
1566 Type [] parameterTypes = typeInfo.getParameterTypes();
1567 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1568
1569 // Convert Types to Classes; returned types *should*
1570 // be class objects since the methodDescriptor's used
1571 // don't have generics information
1572 for (int i = 0; i < parameterClasses.length; i++)
1573 parameterClasses[i] = toClass(parameterTypes[i]);
1574
1575
1576 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1577 Constructor<?>[] candidates = enclosingCandidate
1578 .privateGetDeclaredConstructors(false);
1579 /*
1580 * Loop over all declared constructors; match number
1581 * of and type of parameters.
1582 */
1583 ReflectionFactory fact = getReflectionFactory();
1584 for (Constructor<?> c : candidates) {
1585 if (arrayContentsEq(parameterClasses,
1586 fact.getExecutableSharedParameterTypes(c))) {
1587 return fact.copyConstructor(c);
1588 }
1589 }
1590
1591 throw new InternalError("Enclosing constructor not found");
1592 }
1593 }
1594
1595
1596 /**
1597 * If the class or interface represented by this {@code Class} object
1598 * is a member of another class, returns the {@code Class} object
1599 * representing the class in which it was declared. This method returns
1600 * null if this class or interface is not a member of any other class. If
1601 * this {@code Class} object represents an array class, a primitive
1602 * type, or void, then this method returns null.
1603 *
1604 * @return the declaring class for this class
1605 * @since 1.1
1606 */
1607 public Class<?> getDeclaringClass() {
1608 return getDeclaringClass0();
1609 }
1610
1611 private native Class<?> getDeclaringClass0();
1612
1613
1614 /**
1615 * Returns the immediately enclosing class of the underlying
1616 * class. If the underlying class is a top level class this
1617 * method returns {@code null}.
1618 * @return the immediately enclosing class of the underlying class
1619 * @since 1.5
1620 */
1621 public Class<?> getEnclosingClass() {
1622 // There are five kinds of classes (or interfaces):
1623 // a) Top level classes
1624 // b) Nested classes (static member classes)
1625 // c) Inner classes (non-static member classes)
1626 // d) Local classes (named classes declared within a method)
1627 // e) Anonymous classes
1628
1629
1630 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1631 // attribute if and only if it is a local class or an
1632 // anonymous class.
1633 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1634 Class<?> enclosingCandidate;
1635
1636 if (enclosingInfo == null) {
1637 // This is a top level or a nested class or an inner class (a, b, or c)
1638 enclosingCandidate = getDeclaringClass0();
1639 } else {
1640 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1641 // This is a local class or an anonymous class (d or e)
1642 if (enclosingClass == this || enclosingClass == null)
1643 throw new InternalError("Malformed enclosing method information");
1644 else
1645 enclosingCandidate = enclosingClass;
1646 }
1647 return enclosingCandidate;
1648 }
1649
1650 /**
1651 * Returns the simple name of the underlying class as given in the
1652 * source code. An empty string is returned if the underlying class is
1653 * {@linkplain #isAnonymousClass() anonymous}.
1654 * A {@linkplain #isSynthetic() synthetic class}, one not present
1655 * in source code, can have a non-empty name including special
1656 * characters, such as "{@code $}".
1657 *
1658 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1659 * component type with "[]" appended. In particular the simple
1660 * name of an array class whose component type is anonymous is "[]".
1661 *
1662 * @return the simple name of the underlying class
1663 * @since 1.5
1664 */
1665 public String getSimpleName() {
1666 ReflectionData<T> rd = reflectionData();
1667 String simpleName = rd.simpleName;
1668 if (simpleName == null) {
1669 rd.simpleName = simpleName = getSimpleName0();
1670 }
1671 return simpleName;
1672 }
1673
1674 private String getSimpleName0() {
1675 if (isArray()) {
1676 return getComponentType().getSimpleName().concat("[]");
1677 }
1678 String simpleName = getSimpleBinaryName();
1679 if (simpleName == null) { // top level class
1680 simpleName = getName();
1681 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1682 }
1683 return simpleName;
1684 }
1685
1686 /**
1687 * Return an informative string for the name of this class or interface.
1688 *
1689 * @return an informative string for the name of this class or interface
1690 * @since 1.8
1691 */
1692 public String getTypeName() {
1693 if (isArray()) {
1694 try {
1695 Class<?> cl = this;
1696 int dimensions = 0;
1697 do {
1698 dimensions++;
1699 cl = cl.getComponentType();
1700 } while (cl.isArray());
1701 return cl.getName().concat("[]".repeat(dimensions));
1702 } catch (Throwable e) { /*FALLTHRU*/ }
1703 }
1704 return getName();
1705 }
1706
1707 /**
1708 * Returns the canonical name of the underlying class as
1709 * defined by <cite>The Java Language Specification</cite>.
1710 * Returns {@code null} if the underlying class does not have a canonical
1711 * name. Classes without canonical names include:
1712 * <ul>
1713 * <li>a {@linkplain #isLocalClass() local class}
1714 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1715 * <li>a {@linkplain #isHidden() hidden class}
1716 * <li>an array whose component type does not have a canonical name</li>
1717 * </ul>
1718 *
1719 * The canonical name for a primitive class is the keyword for the
1720 * corresponding primitive type ({@code byte}, {@code short},
1721 * {@code char}, {@code int}, and so on).
1722 *
1723 * <p>An array type has a canonical name if and only if its
1724 * component type has a canonical name. When an array type has a
1725 * canonical name, it is equal to the canonical name of the
1726 * component type followed by "{@code []}".
1727 *
1728 * @return the canonical name of the underlying class if it exists, and
1729 * {@code null} otherwise.
1730 * @jls 6.7 Fully Qualified Names and Canonical Names
1731 * @since 1.5
1732 */
1733 public String getCanonicalName() {
1734 ReflectionData<T> rd = reflectionData();
1735 String canonicalName = rd.canonicalName;
1736 if (canonicalName == null) {
1737 rd.canonicalName = canonicalName = getCanonicalName0();
1738 }
1739 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1740 }
1741
1742 private String getCanonicalName0() {
1743 if (isArray()) {
1744 String canonicalName = getComponentType().getCanonicalName();
1745 if (canonicalName != null)
1746 return canonicalName.concat("[]");
1747 else
1748 return ReflectionData.NULL_SENTINEL;
1749 }
1750 if (isHidden() || isLocalOrAnonymousClass())
1751 return ReflectionData.NULL_SENTINEL;
1752 Class<?> enclosingClass = getEnclosingClass();
1753 if (enclosingClass == null) { // top level class
1754 return getName();
1755 } else {
1756 String enclosingName = enclosingClass.getCanonicalName();
1757 if (enclosingName == null)
1758 return ReflectionData.NULL_SENTINEL;
1759 String simpleName = getSimpleName();
1760 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1761 .append(enclosingName)
1762 .append('.')
1763 .append(simpleName)
1764 .toString();
1765 }
1766 }
1767
1768 /**
1769 * Returns {@code true} if and only if the underlying class
1770 * is an anonymous class.
1771 *
1772 * @apiNote
1773 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1774 *
1775 * @return {@code true} if and only if this class is an anonymous class.
1776 * @since 1.5
1777 * @jls 15.9.5 Anonymous Class Declarations
1778 */
1779 public boolean isAnonymousClass() {
1780 return !isArray() && isLocalOrAnonymousClass() &&
1781 getSimpleBinaryName0() == null;
1782 }
1783
1784 /**
1785 * Returns {@code true} if and only if the underlying class
1786 * is a local class.
1787 *
1788 * @return {@code true} if and only if this class is a local class.
1789 * @since 1.5
1790 * @jls 14.3 Local Class and Interface Declarations
1791 */
1792 public boolean isLocalClass() {
1793 return isLocalOrAnonymousClass() &&
1794 (isArray() || getSimpleBinaryName0() != null);
1795 }
1796
1797 /**
1798 * Returns {@code true} if and only if the underlying class
1799 * is a member class.
1800 *
1801 * @return {@code true} if and only if this class is a member class.
1802 * @since 1.5
1803 * @jls 8.5 Member Class and Interface Declarations
1804 */
1805 public boolean isMemberClass() {
1806 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1807 }
1808
1809 /**
1810 * Returns the "simple binary name" of the underlying class, i.e.,
1811 * the binary name without the leading enclosing class name.
1812 * Returns {@code null} if the underlying class is a top level
1813 * class.
1814 */
1815 private String getSimpleBinaryName() {
1816 if (isTopLevelClass())
1817 return null;
1818 String name = getSimpleBinaryName0();
1819 if (name == null) // anonymous class
1820 return "";
1821 return name;
1822 }
1823
1824 private native String getSimpleBinaryName0();
1825
1826 /**
1827 * Returns {@code true} if this is a top level class. Returns {@code false}
1828 * otherwise.
1829 */
1830 private boolean isTopLevelClass() {
1831 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1832 }
1833
1834 /**
1835 * Returns {@code true} if this is a local class or an anonymous
1836 * class. Returns {@code false} otherwise.
1837 */
1838 private boolean isLocalOrAnonymousClass() {
1839 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1840 // attribute if and only if it is a local class or an
1841 // anonymous class.
1842 return hasEnclosingMethodInfo();
1843 }
1844
1845 private boolean hasEnclosingMethodInfo() {
1846 Object[] enclosingInfo = getEnclosingMethod0();
1847 if (enclosingInfo != null) {
1848 EnclosingMethodInfo.validate(enclosingInfo);
1849 return true;
1850 }
1851 return false;
1852 }
1853
1854 /**
1855 * Returns an array containing {@code Class} objects representing all
1856 * the public classes and interfaces that are members of the class
1857 * represented by this {@code Class} object. This includes public
1858 * class and interface members inherited from superclasses and public class
1859 * and interface members declared by the class. This method returns an
1860 * array of length 0 if this {@code Class} object has no public member
1861 * classes or interfaces. This method also returns an array of length 0 if
1862 * this {@code Class} object represents a primitive type, an array
1863 * class, or void.
1864 *
1865 * @return the array of {@code Class} objects representing the public
1866 * members of this class
1867 * @since 1.1
1868 */
1869 public Class<?>[] getClasses() {
1870 List<Class<?>> list = new ArrayList<>();
1871 Class<?> currentClass = Class.this;
1872 while (currentClass != null) {
1873 for (Class<?> m : currentClass.getDeclaredClasses()) {
1874 if (Modifier.isPublic(m.getModifiers())) {
1875 list.add(m);
1876 }
1877 }
1878 currentClass = currentClass.getSuperclass();
1879 }
1880 return list.toArray(new Class<?>[0]);
1881 }
1882
1883
1884 /**
1885 * Returns an array containing {@code Field} objects reflecting all
1886 * the accessible public fields of the class or interface represented by
1887 * this {@code Class} object.
1888 *
1889 * <p> If this {@code Class} object represents a class or interface with
1890 * no accessible public fields, then this method returns an array of length
1891 * 0.
1892 *
1893 * <p> If this {@code Class} object represents a class, then this method
1894 * returns the public fields of the class and of all its superclasses and
1895 * superinterfaces.
1896 *
1897 * <p> If this {@code Class} object represents an interface, then this
1898 * method returns the fields of the interface and of all its
1899 * superinterfaces.
1900 *
1901 * <p> If this {@code Class} object represents an array type, a primitive
1902 * type, or void, then this method returns an array of length 0.
1903 *
1904 * <p> The elements in the returned array are not sorted and are not in any
1905 * particular order.
1906 *
1907 * @return the array of {@code Field} objects representing the
1908 * public fields
1909 *
1910 * @since 1.1
1911 * @jls 8.2 Class Members
1912 * @jls 8.3 Field Declarations
1913 */
1914 public Field[] getFields() {
1915 return copyFields(privateGetPublicFields());
1916 }
1917
1918
1919 /**
1920 * Returns an array containing {@code Method} objects reflecting all the
1921 * public methods of the class or interface represented by this {@code
1922 * Class} object, including those declared by the class or interface and
1923 * those inherited from superclasses and superinterfaces.
1924 *
1925 * <p> If this {@code Class} object represents an array type, then the
1926 * returned array has a {@code Method} object for each of the public
1927 * methods inherited by the array type from {@code Object}. It does not
1928 * contain a {@code Method} object for {@code clone()}.
1929 *
1930 * <p> If this {@code Class} object represents an interface then the
1931 * returned array does not contain any implicitly declared methods from
1932 * {@code Object}. Therefore, if no methods are explicitly declared in
1933 * this interface or any of its superinterfaces then the returned array
1934 * has length 0. (Note that a {@code Class} object which represents a class
1935 * always has public methods, inherited from {@code Object}.)
1936 *
1937 * <p> The returned array never contains methods with names {@value
1938 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1939 *
1940 * <p> The elements in the returned array are not sorted and are not in any
1941 * particular order.
1942 *
1943 * <p> Generally, the result is computed as with the following 4 step algorithm.
1944 * Let C be the class or interface represented by this {@code Class} object:
1945 * <ol>
1946 * <li> A union of methods is composed of:
1947 * <ol type="a">
1948 * <li> C's declared public instance and static methods as returned by
1949 * {@link #getDeclaredMethods()} and filtered to include only public
1950 * methods.</li>
1951 * <li> If C is a class other than {@code Object}, then include the result
1952 * of invoking this algorithm recursively on the superclass of C.</li>
1953 * <li> Include the results of invoking this algorithm recursively on all
1954 * direct superinterfaces of C, but include only instance methods.</li>
1955 * </ol></li>
1956 * <li> Union from step 1 is partitioned into subsets of methods with same
1957 * signature (name, parameter types) and return type.</li>
1958 * <li> Within each such subset only the most specific methods are selected.
1959 * Let method M be a method from a set of methods with same signature
1960 * and return type. M is most specific if there is no such method
1961 * N != M from the same set, such that N is more specific than M.
1962 * N is more specific than M if:
1963 * <ol type="a">
1964 * <li> N is declared by a class and M is declared by an interface; or</li>
1965 * <li> N and M are both declared by classes or both by interfaces and
1966 * N's declaring type is the same as or a subtype of M's declaring type
1967 * (clearly, if M's and N's declaring types are the same type, then
1968 * M and N are the same method).</li>
1969 * </ol></li>
1970 * <li> The result of this algorithm is the union of all selected methods from
1971 * step 3.</li>
1972 * </ol>
1973 *
1974 * @apiNote There may be more than one method with a particular name
1975 * and parameter types in a class because while the Java language forbids a
1976 * class to declare multiple methods with the same signature but different
1977 * return types, the Java virtual machine does not. This
1978 * increased flexibility in the virtual machine can be used to
1979 * implement various language features. For example, covariant
1980 * returns can be implemented with {@linkplain
1981 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
1982 * method and the overriding method would have the same
1983 * signature but different return types.
1984 *
1985 * @return the array of {@code Method} objects representing the
1986 * public methods of this class
1987 *
1988 * @jls 8.2 Class Members
1989 * @jls 8.4 Method Declarations
1990 * @since 1.1
1991 */
1992 public Method[] getMethods() {
1993 return copyMethods(privateGetPublicMethods());
1994 }
1995
1996
1997 /**
1998 * Returns an array containing {@code Constructor} objects reflecting
1999 * all the public constructors of the class represented by this
2000 * {@code Class} object. An array of length 0 is returned if the
2001 * class has no public constructors, or if the class is an array class, or
2002 * if the class reflects a primitive type or void.
2003 *
2004 * @apiNote
2005 * While this method returns an array of {@code
2006 * Constructor<T>} objects (that is an array of constructors from
2007 * this class), the return type of this method is {@code
2008 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2009 * might be expected. This less informative return type is
2010 * necessary since after being returned from this method, the
2011 * array could be modified to hold {@code Constructor} objects for
2012 * different classes, which would violate the type guarantees of
2013 * {@code Constructor<T>[]}.
2014 *
2015 * @return the array of {@code Constructor} objects representing the
2016 * public constructors of this class
2017 *
2018 * @see #getDeclaredConstructors()
2019 * @since 1.1
2020 */
2021 public Constructor<?>[] getConstructors() {
2022 return copyConstructors(privateGetDeclaredConstructors(true));
2023 }
2024
2025
2026 /**
2027 * Returns a {@code Field} object that reflects the specified public member
2028 * field of the class or interface represented by this {@code Class}
2029 * object. The {@code name} parameter is a {@code String} specifying the
2030 * simple name of the desired field.
2031 *
2032 * <p> The field to be reflected is determined by the algorithm that
2033 * follows. Let C be the class or interface represented by this {@code Class} object:
2034 *
2035 * <OL>
2036 * <LI> If C declares a public field with the name specified, that is the
2037 * field to be reflected.</LI>
2038 * <LI> If no field was found in step 1 above, this algorithm is applied
2039 * recursively to each direct superinterface of C. The direct
2040 * superinterfaces are searched in the order they were declared.</LI>
2041 * <LI> If no field was found in steps 1 and 2 above, and C has a
2042 * superclass S, then this algorithm is invoked recursively upon S.
2043 * If C has no superclass, then a {@code NoSuchFieldException}
2044 * is thrown.</LI>
2045 * </OL>
2046 *
2047 * <p> If this {@code Class} object represents an array type, then this
2048 * method does not find the {@code length} field of the array type.
2049 *
2050 * @param name the field name
2051 * @return the {@code Field} object of this class specified by
2052 * {@code name}
2053 * @throws NoSuchFieldException if a field with the specified name is
2054 * not found.
2055 * @throws NullPointerException if {@code name} is {@code null}
2056 *
2057 * @since 1.1
2058 * @jls 8.2 Class Members
2059 * @jls 8.3 Field Declarations
2060 */
2061 public Field getField(String name) throws NoSuchFieldException {
2062 Objects.requireNonNull(name);
2063 Field field = getField0(name);
2064 if (field == null) {
2065 throw new NoSuchFieldException(name);
2066 }
2067 return getReflectionFactory().copyField(field);
2068 }
2069
2070
2071 /**
2072 * Returns a {@code Method} object that reflects the specified public
2073 * member method of the class or interface represented by this
2074 * {@code Class} object. The {@code name} parameter is a
2075 * {@code String} specifying the simple name of the desired method. The
2076 * {@code parameterTypes} parameter is an array of {@code Class}
2077 * objects that identify the method's formal parameter types, in declared
2078 * order. If {@code parameterTypes} is {@code null}, it is
2079 * treated as if it were an empty array.
2080 *
2081 * <p> If this {@code Class} object represents an array type, then this
2082 * method finds any public method inherited by the array type from
2083 * {@code Object} except method {@code clone()}.
2084 *
2085 * <p> If this {@code Class} object represents an interface then this
2086 * method does not find any implicitly declared method from
2087 * {@code Object}. Therefore, if no methods are explicitly declared in
2088 * this interface or any of its superinterfaces, then this method does not
2089 * find any method.
2090 *
2091 * <p> This method does not find any method with name {@value
2092 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2093 *
2094 * <p> Generally, the method to be reflected is determined by the 4 step
2095 * algorithm that follows.
2096 * Let C be the class or interface represented by this {@code Class} object:
2097 * <ol>
2098 * <li> A union of methods is composed of:
2099 * <ol type="a">
2100 * <li> C's declared public instance and static methods as returned by
2101 * {@link #getDeclaredMethods()} and filtered to include only public
2102 * methods that match given {@code name} and {@code parameterTypes}</li>
2103 * <li> If C is a class other than {@code Object}, then include the result
2104 * of invoking this algorithm recursively on the superclass of C.</li>
2105 * <li> Include the results of invoking this algorithm recursively on all
2106 * direct superinterfaces of C, but include only instance methods.</li>
2107 * </ol></li>
2108 * <li> This union is partitioned into subsets of methods with same
2109 * return type (the selection of methods from step 1 also guarantees that
2110 * they have the same method name and parameter types).</li>
2111 * <li> Within each such subset only the most specific methods are selected.
2112 * Let method M be a method from a set of methods with same VM
2113 * signature (return type, name, parameter types).
2114 * M is most specific if there is no such method N != M from the same
2115 * set, such that N is more specific than M. N is more specific than M
2116 * if:
2117 * <ol type="a">
2118 * <li> N is declared by a class and M is declared by an interface; or</li>
2119 * <li> N and M are both declared by classes or both by interfaces and
2120 * N's declaring type is the same as or a subtype of M's declaring type
2121 * (clearly, if M's and N's declaring types are the same type, then
2122 * M and N are the same method).</li>
2123 * </ol></li>
2124 * <li> The result of this algorithm is chosen arbitrarily from the methods
2125 * with most specific return type among all selected methods from step 3.
2126 * Let R be a return type of a method M from the set of all selected methods
2127 * from step 3. M is a method with most specific return type if there is
2128 * no such method N != M from the same set, having return type S != R,
2129 * such that S is a subtype of R as determined by
2130 * R.class.{@link #isAssignableFrom}(S.class).
2131 * </ol>
2132 *
2133 * @apiNote There may be more than one method with matching name and
2134 * parameter types in a class because while the Java language forbids a
2135 * class to declare multiple methods with the same signature but different
2136 * return types, the Java virtual machine does not. This
2137 * increased flexibility in the virtual machine can be used to
2138 * implement various language features. For example, covariant
2139 * returns can be implemented with {@linkplain
2140 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2141 * method and the overriding method would have the same
2142 * signature but different return types. This method would return the
2143 * overriding method as it would have a more specific return type.
2144 *
2145 * @param name the name of the method
2146 * @param parameterTypes the list of parameters
2147 * @return the {@code Method} object that matches the specified
2148 * {@code name} and {@code parameterTypes}
2149 * @throws NoSuchMethodException if a matching method is not found
2150 * or if the name is {@value ConstantDescs#INIT_NAME} or
2151 * {@value ConstantDescs#CLASS_INIT_NAME}.
2152 * @throws NullPointerException if {@code name} is {@code null}
2153 *
2154 * @jls 8.2 Class Members
2155 * @jls 8.4 Method Declarations
2156 * @since 1.1
2157 */
2158 public Method getMethod(String name, Class<?>... parameterTypes)
2159 throws NoSuchMethodException {
2160 Objects.requireNonNull(name);
2161 Method method = getMethod0(name, parameterTypes);
2162 if (method == null) {
2163 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2164 }
2165 return getReflectionFactory().copyMethod(method);
2166 }
2167
2168 /**
2169 * Returns a {@code Constructor} object that reflects the specified
2170 * public constructor of the class represented by this {@code Class}
2171 * object. The {@code parameterTypes} parameter is an array of
2172 * {@code Class} objects that identify the constructor's formal
2173 * parameter types, in declared order.
2174 *
2175 * If this {@code Class} object represents an inner class
2176 * declared in a non-static context, the formal parameter types
2177 * include the explicit enclosing instance as the first parameter.
2178 *
2179 * <p> The constructor to reflect is the public constructor of the class
2180 * represented by this {@code Class} object whose formal parameter
2181 * types match those specified by {@code parameterTypes}.
2182 *
2183 * @param parameterTypes the parameter array
2184 * @return the {@code Constructor} object of the public constructor that
2185 * matches the specified {@code parameterTypes}
2186 * @throws NoSuchMethodException if a matching constructor is not found,
2187 * including when this {@code Class} object represents
2188 * an interface, a primitive type, an array class, or void.
2189 *
2190 * @see #getDeclaredConstructor(Class[])
2191 * @since 1.1
2192 */
2193 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2194 throws NoSuchMethodException {
2195 return getReflectionFactory().copyConstructor(
2196 getConstructor0(parameterTypes, Member.PUBLIC));
2197 }
2198
2199
2200 /**
2201 * Returns an array of {@code Class} objects reflecting all the
2202 * classes and interfaces declared as members of the class represented by
2203 * this {@code Class} object. This includes public, protected, default
2204 * (package) access, and private classes and interfaces declared by the
2205 * class, but excludes inherited classes and interfaces. This method
2206 * returns an array of length 0 if the class declares no classes or
2207 * interfaces as members, or if this {@code Class} object represents a
2208 * primitive type, an array class, or void.
2209 *
2210 * @return the array of {@code Class} objects representing all the
2211 * declared members of this class
2212 *
2213 * @since 1.1
2214 * @jls 8.5 Member Class and Interface Declarations
2215 */
2216 public Class<?>[] getDeclaredClasses() {
2217 return getDeclaredClasses0();
2218 }
2219
2220
2221 /**
2222 * Returns an array of {@code Field} objects reflecting all the fields
2223 * declared by the class or interface represented by this
2224 * {@code Class} object. This includes public, protected, default
2225 * (package) access, and private fields, but excludes inherited fields.
2226 *
2227 * <p> If this {@code Class} object represents a class or interface with no
2228 * declared fields, then this method returns an array of length 0.
2229 *
2230 * <p> If this {@code Class} object represents an array type, a primitive
2231 * type, or void, then this method returns an array of length 0.
2232 *
2233 * <p> The elements in the returned array are not sorted and are not in any
2234 * particular order.
2235 *
2236 * @return the array of {@code Field} objects representing all the
2237 * declared fields of this class
2238 *
2239 * @since 1.1
2240 * @jls 8.2 Class Members
2241 * @jls 8.3 Field Declarations
2242 */
2243 public Field[] getDeclaredFields() {
2244 return copyFields(privateGetDeclaredFields(false));
2245 }
2246
2247 /**
2248 * Returns an array of {@code RecordComponent} objects representing all the
2249 * record components of this record class, or {@code null} if this class is
2250 * not a record class.
2251 *
2252 * <p> The components are returned in the same order that they are declared
2253 * in the record header. The array is empty if this record class has no
2254 * components. If the class is not a record class, that is {@link
2255 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2256 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2257 * returns a non-null value.
2258 *
2259 * @apiNote
2260 * <p> The following method can be used to find the record canonical constructor:
2261 *
2262 * {@snippet lang="java" :
2263 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2264 * throws NoSuchMethodException {
2265 * Class<?>[] paramTypes =
2266 * Arrays.stream(cls.getRecordComponents())
2267 * .map(RecordComponent::getType)
2268 * .toArray(Class<?>[]::new);
2269 * return cls.getDeclaredConstructor(paramTypes);
2270 * }}
2271 *
2272 * @return An array of {@code RecordComponent} objects representing all the
2273 * record components of this record class, or {@code null} if this
2274 * class is not a record class
2275 *
2276 * @jls 8.10 Record Classes
2277 * @since 16
2278 */
2279 public RecordComponent[] getRecordComponents() {
2280 if (!isRecord()) {
2281 return null;
2282 }
2283 return getRecordComponents0();
2284 }
2285
2286 /**
2287 * Returns an array containing {@code Method} objects reflecting all the
2288 * declared methods of the class or interface represented by this {@code
2289 * Class} object, including public, protected, default (package)
2290 * access, and private methods, but excluding inherited methods.
2291 * The declared methods may include methods <em>not</em> in the
2292 * source of the class or interface, including {@linkplain
2293 * Method#isBridge bridge methods} and other {@linkplain
2294 * Executable#isSynthetic synthetic} methods added by compilers.
2295 *
2296 * <p> If this {@code Class} object represents a class or interface that
2297 * has multiple declared methods with the same name and parameter types,
2298 * but different return types, then the returned array has a {@code Method}
2299 * object for each such method.
2300 *
2301 * <p> If this {@code Class} object represents a class or interface that
2302 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2303 * then the returned array does <em>not</em> have a corresponding {@code
2304 * Method} object.
2305 *
2306 * <p> If this {@code Class} object represents a class or interface with no
2307 * declared methods, then the returned array has length 0.
2308 *
2309 * <p> If this {@code Class} object represents an array type, a primitive
2310 * type, or void, then the returned array has length 0.
2311 *
2312 * <p> The elements in the returned array are not sorted and are not in any
2313 * particular order.
2314 *
2315 * @return the array of {@code Method} objects representing all the
2316 * declared methods of this class
2317 *
2318 * @jls 8.2 Class Members
2319 * @jls 8.4 Method Declarations
2320 * @see <a
2321 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2322 * programming language and JVM modeling in core reflection</a>
2323 * @since 1.1
2324 */
2325 public Method[] getDeclaredMethods() {
2326 return copyMethods(privateGetDeclaredMethods(false));
2327 }
2328
2329 /**
2330 * Returns an array of {@code Constructor} objects reflecting all the
2331 * constructors implicitly or explicitly declared by the class represented by this
2332 * {@code Class} object. These are public, protected, default
2333 * (package) access, and private constructors. The elements in the array
2334 * returned are not sorted and are not in any particular order. If the
2335 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2336 * If a record class has a canonical constructor (JLS {@jls
2337 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2338 *
2339 * This method returns an array of length 0 if this {@code Class}
2340 * object represents an interface, a primitive type, an array class, or
2341 * void.
2342 *
2343 * @return the array of {@code Constructor} objects representing all the
2344 * declared constructors of this class
2345 *
2346 * @since 1.1
2347 * @see #getConstructors()
2348 * @jls 8.8 Constructor Declarations
2349 */
2350 public Constructor<?>[] getDeclaredConstructors() {
2351 return copyConstructors(privateGetDeclaredConstructors(false));
2352 }
2353
2354
2355 /**
2356 * Returns a {@code Field} object that reflects the specified declared
2357 * field of the class or interface represented by this {@code Class}
2358 * object. The {@code name} parameter is a {@code String} that specifies
2359 * the simple name of the desired field.
2360 *
2361 * <p> If this {@code Class} object represents an array type, then this
2362 * method does not find the {@code length} field of the array type.
2363 *
2364 * @param name the name of the field
2365 * @return the {@code Field} object for the specified field in this
2366 * class
2367 * @throws NoSuchFieldException if a field with the specified name is
2368 * not found.
2369 * @throws NullPointerException if {@code name} is {@code null}
2370 *
2371 * @since 1.1
2372 * @jls 8.2 Class Members
2373 * @jls 8.3 Field Declarations
2374 */
2375 public Field getDeclaredField(String name) throws NoSuchFieldException {
2376 Objects.requireNonNull(name);
2377 Field field = searchFields(privateGetDeclaredFields(false), name);
2378 if (field == null) {
2379 throw new NoSuchFieldException(name);
2380 }
2381 return getReflectionFactory().copyField(field);
2382 }
2383
2384
2385 /**
2386 * Returns a {@code Method} object that reflects the specified
2387 * declared method of the class or interface represented by this
2388 * {@code Class} object. The {@code name} parameter is a
2389 * {@code String} that specifies the simple name of the desired
2390 * method, and the {@code parameterTypes} parameter is an array of
2391 * {@code Class} objects that identify the method's formal parameter
2392 * types, in declared order. If more than one method with the same
2393 * parameter types is declared in a class, and one of these methods has a
2394 * return type that is more specific than any of the others, that method is
2395 * returned; otherwise one of the methods is chosen arbitrarily. If the
2396 * name is {@value ConstantDescs#INIT_NAME} or {@value
2397 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2398 * is raised.
2399 *
2400 * <p> If this {@code Class} object represents an array type, then this
2401 * method does not find the {@code clone()} method.
2402 *
2403 * @param name the name of the method
2404 * @param parameterTypes the parameter array
2405 * @return the {@code Method} object for the method of this class
2406 * matching the specified name and parameters
2407 * @throws NoSuchMethodException if a matching method is not found.
2408 * @throws NullPointerException if {@code name} is {@code null}
2409 *
2410 * @jls 8.2 Class Members
2411 * @jls 8.4 Method Declarations
2412 * @since 1.1
2413 */
2414 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2415 throws NoSuchMethodException {
2416 Objects.requireNonNull(name);
2417 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2418 if (method == null) {
2419 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2420 }
2421 return getReflectionFactory().copyMethod(method);
2422 }
2423
2424 /**
2425 * Returns the list of {@code Method} objects for the declared public
2426 * methods of this class or interface that have the specified method name
2427 * and parameter types.
2428 *
2429 * @param name the name of the method
2430 * @param parameterTypes the parameter array
2431 * @return the list of {@code Method} objects for the public methods of
2432 * this class matching the specified name and parameters
2433 */
2434 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2435 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2436 ReflectionFactory factory = getReflectionFactory();
2437 List<Method> result = new ArrayList<>();
2438 for (Method method : methods) {
2439 if (method.getName().equals(name)
2440 && Arrays.equals(
2441 factory.getExecutableSharedParameterTypes(method),
2442 parameterTypes)) {
2443 result.add(factory.copyMethod(method));
2444 }
2445 }
2446 return result;
2447 }
2448
2449 /**
2450 * Returns the most specific {@code Method} object of this class, super class or
2451 * interface that have the specified method name and parameter types.
2452 *
2453 * @param publicOnly true if only public methods are examined, otherwise all methods
2454 * @param name the name of the method
2455 * @param parameterTypes the parameter array
2456 * @return the {@code Method} object for the method found from this class matching
2457 * the specified name and parameters, or null if not found
2458 */
2459 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2460 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2461 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2462 }
2463
2464 /**
2465 * Returns a {@code Constructor} object that reflects the specified
2466 * constructor of the class represented by this
2467 * {@code Class} object. The {@code parameterTypes} parameter is
2468 * an array of {@code Class} objects that identify the constructor's
2469 * formal parameter types, in declared order.
2470 *
2471 * If this {@code Class} object represents an inner class
2472 * declared in a non-static context, the formal parameter types
2473 * include the explicit enclosing instance as the first parameter.
2474 *
2475 * @param parameterTypes the parameter array
2476 * @return The {@code Constructor} object for the constructor with the
2477 * specified parameter list
2478 * @throws NoSuchMethodException if a matching constructor is not found,
2479 * including when this {@code Class} object represents
2480 * an interface, a primitive type, an array class, or void.
2481 *
2482 * @see #getConstructor(Class[])
2483 * @since 1.1
2484 */
2485 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2486 throws NoSuchMethodException {
2487 return getReflectionFactory().copyConstructor(
2488 getConstructor0(parameterTypes, Member.DECLARED));
2489 }
2490
2491 /**
2492 * Finds a resource with a given name.
2493 *
2494 * <p> If this class is in a named {@link Module Module} then this method
2495 * will attempt to find the resource in the module. This is done by
2496 * delegating to the module's class loader {@link
2497 * ClassLoader#findResource(String,String) findResource(String,String)}
2498 * method, invoking it with the module name and the absolute name of the
2499 * resource. Resources in named modules are subject to the rules for
2500 * encapsulation specified in the {@code Module} {@link
2501 * Module#getResourceAsStream getResourceAsStream} method and so this
2502 * method returns {@code null} when the resource is a
2503 * non-"{@code .class}" resource in a package that is not open to the
2504 * caller's module.
2505 *
2506 * <p> Otherwise, if this class is not in a named module then the rules for
2507 * searching resources associated with a given class are implemented by the
2508 * defining {@linkplain ClassLoader class loader} of the class. This method
2509 * delegates to this {@code Class} object's class loader.
2510 * If this {@code Class} object was loaded by the bootstrap class loader,
2511 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2512 *
2513 * <p> Before delegation, an absolute resource name is constructed from the
2514 * given resource name using this algorithm:
2515 *
2516 * <ul>
2517 *
2518 * <li> If the {@code name} begins with a {@code '/'}
2519 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2520 * portion of the {@code name} following the {@code '/'}.
2521 *
2522 * <li> Otherwise, the absolute name is of the following form:
2523 *
2524 * <blockquote>
2525 * {@code modified_package_name/name}
2526 * </blockquote>
2527 *
2528 * <p> Where the {@code modified_package_name} is the package name of this
2529 * object with {@code '/'} substituted for {@code '.'}
2530 * (<code>'\u002e'</code>).
2531 *
2532 * </ul>
2533 *
2534 * @param name name of the desired resource
2535 * @return A {@link java.io.InputStream} object; {@code null} if no
2536 * resource with this name is found, or the resource is in a package
2537 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2538 * least the caller module.
2539 * @throws NullPointerException If {@code name} is {@code null}
2540 *
2541 * @see Module#getResourceAsStream(String)
2542 * @since 1.1
2543 */
2544 @CallerSensitive
2545 public InputStream getResourceAsStream(String name) {
2546 name = resolveName(name);
2547
2548 Module thisModule = getModule();
2549 if (thisModule.isNamed()) {
2550 // check if resource can be located by caller
2551 if (Resources.canEncapsulate(name)
2552 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2553 return null;
2554 }
2555
2556 // resource not encapsulated or in package open to caller
2557 String mn = thisModule.getName();
2558 ClassLoader cl = classLoader;
2559 try {
2560
2561 // special-case built-in class loaders to avoid the
2562 // need for a URL connection
2563 if (cl == null) {
2564 return BootLoader.findResourceAsStream(mn, name);
2565 } else if (cl instanceof BuiltinClassLoader bcl) {
2566 return bcl.findResourceAsStream(mn, name);
2567 } else {
2568 URL url = cl.findResource(mn, name);
2569 return (url != null) ? url.openStream() : null;
2570 }
2571
2572 } catch (IOException | SecurityException e) {
2573 return null;
2574 }
2575 }
2576
2577 // unnamed module
2578 ClassLoader cl = classLoader;
2579 if (cl == null) {
2580 return ClassLoader.getSystemResourceAsStream(name);
2581 } else {
2582 return cl.getResourceAsStream(name);
2583 }
2584 }
2585
2586 /**
2587 * Finds a resource with a given name.
2588 *
2589 * <p> If this class is in a named {@link Module Module} then this method
2590 * will attempt to find the resource in the module. This is done by
2591 * delegating to the module's class loader {@link
2592 * ClassLoader#findResource(String,String) findResource(String,String)}
2593 * method, invoking it with the module name and the absolute name of the
2594 * resource. Resources in named modules are subject to the rules for
2595 * encapsulation specified in the {@code Module} {@link
2596 * Module#getResourceAsStream getResourceAsStream} method and so this
2597 * method returns {@code null} when the resource is a
2598 * non-"{@code .class}" resource in a package that is not open to the
2599 * caller's module.
2600 *
2601 * <p> Otherwise, if this class is not in a named module then the rules for
2602 * searching resources associated with a given class are implemented by the
2603 * defining {@linkplain ClassLoader class loader} of the class. This method
2604 * delegates to this {@code Class} object's class loader.
2605 * If this {@code Class} object was loaded by the bootstrap class loader,
2606 * the method delegates to {@link ClassLoader#getSystemResource}.
2607 *
2608 * <p> Before delegation, an absolute resource name is constructed from the
2609 * given resource name using this algorithm:
2610 *
2611 * <ul>
2612 *
2613 * <li> If the {@code name} begins with a {@code '/'}
2614 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2615 * portion of the {@code name} following the {@code '/'}.
2616 *
2617 * <li> Otherwise, the absolute name is of the following form:
2618 *
2619 * <blockquote>
2620 * {@code modified_package_name/name}
2621 * </blockquote>
2622 *
2623 * <p> Where the {@code modified_package_name} is the package name of this
2624 * object with {@code '/'} substituted for {@code '.'}
2625 * (<code>'\u002e'</code>).
2626 *
2627 * </ul>
2628 *
2629 * @param name name of the desired resource
2630 * @return A {@link java.net.URL} object; {@code null} if no resource with
2631 * this name is found, the resource cannot be located by a URL, or the
2632 * resource is in a package that is not
2633 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2634 * module.
2635 * @throws NullPointerException If {@code name} is {@code null}
2636 * @since 1.1
2637 */
2638 @CallerSensitive
2639 public URL getResource(String name) {
2640 name = resolveName(name);
2641
2642 Module thisModule = getModule();
2643 if (thisModule.isNamed()) {
2644 // check if resource can be located by caller
2645 if (Resources.canEncapsulate(name)
2646 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2647 return null;
2648 }
2649
2650 // resource not encapsulated or in package open to caller
2651 String mn = thisModule.getName();
2652 ClassLoader cl = classLoader;
2653 try {
2654 if (cl == null) {
2655 return BootLoader.findResource(mn, name);
2656 } else {
2657 return cl.findResource(mn, name);
2658 }
2659 } catch (IOException ioe) {
2660 return null;
2661 }
2662 }
2663
2664 // unnamed module
2665 ClassLoader cl = classLoader;
2666 if (cl == null) {
2667 return ClassLoader.getSystemResource(name);
2668 } else {
2669 return cl.getResource(name);
2670 }
2671 }
2672
2673 /**
2674 * Returns true if a resource with the given name can be located by the
2675 * given caller. All resources in a module can be located by code in
2676 * the module. For other callers, then the package needs to be open to
2677 * the caller.
2678 */
2679 private boolean isOpenToCaller(String name, Class<?> caller) {
2680 // assert getModule().isNamed();
2681 Module thisModule = getModule();
2682 Module callerModule = (caller != null) ? caller.getModule() : null;
2683 if (callerModule != thisModule) {
2684 String pn = Resources.toPackageName(name);
2685 if (thisModule.getDescriptor().packages().contains(pn)) {
2686 if (callerModule == null) {
2687 // no caller, return true if the package is open to all modules
2688 return thisModule.isOpen(pn);
2689 }
2690 if (!thisModule.isOpen(pn, callerModule)) {
2691 // package not open to caller
2692 return false;
2693 }
2694 }
2695 }
2696 return true;
2697 }
2698
2699 /**
2700 * Returns the {@code ProtectionDomain} of this class.
2701 *
2702 * @return the ProtectionDomain of this class
2703 *
2704 * @see java.security.ProtectionDomain
2705 * @since 1.2
2706 */
2707 public ProtectionDomain getProtectionDomain() {
2708 return protectionDomain();
2709 }
2710
2711 /** Holder for the protection domain returned when the internal domain is null */
2712 private static class Holder {
2713 private static final ProtectionDomain allPermDomain;
2714 static {
2715 Permissions perms = new Permissions();
2716 perms.add(new AllPermission());
2717 allPermDomain = new ProtectionDomain(null, perms);
2718 }
2719 }
2720
2721 // package-private
2722 ProtectionDomain protectionDomain() {
2723 ProtectionDomain pd = getProtectionDomain0();
2724 if (pd == null) {
2725 return Holder.allPermDomain;
2726 } else {
2727 return pd;
2728 }
2729 }
2730
2731 /**
2732 * Returns the ProtectionDomain of this class.
2733 */
2734 private native ProtectionDomain getProtectionDomain0();
2735
2736 /*
2737 * Returns the Class object for the named primitive type. Type parameter T
2738 * avoids redundant casts for trusted code.
2739 */
2740 static native <T> Class<T> getPrimitiveClass(String name);
2741
2742 /**
2743 * Add a package name prefix if the name is not absolute. Remove leading "/"
2744 * if name is absolute
2745 */
2746 private String resolveName(String name) {
2747 if (!name.startsWith("/")) {
2748 String baseName = getPackageName();
2749 if (!baseName.isEmpty()) {
2750 int len = baseName.length() + 1 + name.length();
2751 StringBuilder sb = new StringBuilder(len);
2752 name = sb.append(baseName.replace('.', '/'))
2753 .append('/')
2754 .append(name)
2755 .toString();
2756 }
2757 } else {
2758 name = name.substring(1);
2759 }
2760 return name;
2761 }
2762
2763 /**
2764 * Atomic operations support.
2765 */
2766 private static class Atomic {
2767 // initialize Unsafe machinery here, since we need to call Class.class instance method
2768 // and have to avoid calling it in the static initializer of the Class class...
2769 private static final Unsafe unsafe = Unsafe.getUnsafe();
2770 // offset of Class.reflectionData instance field
2771 private static final long reflectionDataOffset
2772 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2773 // offset of Class.annotationType instance field
2774 private static final long annotationTypeOffset
2775 = unsafe.objectFieldOffset(Class.class, "annotationType");
2776 // offset of Class.annotationData instance field
2777 private static final long annotationDataOffset
2778 = unsafe.objectFieldOffset(Class.class, "annotationData");
2779
2780 static <T> boolean casReflectionData(Class<?> clazz,
2781 SoftReference<ReflectionData<T>> oldData,
2782 SoftReference<ReflectionData<T>> newData) {
2783 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2784 }
2785
2786 static boolean casAnnotationType(Class<?> clazz,
2787 AnnotationType oldType,
2788 AnnotationType newType) {
2789 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2790 }
2791
2792 static boolean casAnnotationData(Class<?> clazz,
2793 AnnotationData oldData,
2794 AnnotationData newData) {
2795 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2796 }
2797 }
2798
2799 /**
2800 * Reflection support.
2801 */
2802
2803 // Reflection data caches various derived names and reflective members. Cached
2804 // values may be invalidated when JVM TI RedefineClasses() is called
2805 private static class ReflectionData<T> {
2806 volatile Field[] declaredFields;
2807 volatile Field[] publicFields;
2808 volatile Method[] declaredMethods;
2809 volatile Method[] publicMethods;
2810 volatile Constructor<T>[] declaredConstructors;
2811 volatile Constructor<T>[] publicConstructors;
2812 // Intermediate results for getFields and getMethods
2813 volatile Field[] declaredPublicFields;
2814 volatile Method[] declaredPublicMethods;
2815 volatile Class<?>[] interfaces;
2816
2817 // Cached names
2818 String simpleName;
2819 String canonicalName;
2820 static final String NULL_SENTINEL = new String();
2821
2822 // Value of classRedefinedCount when we created this ReflectionData instance
2823 final int redefinedCount;
2824
2825 ReflectionData(int redefinedCount) {
2826 this.redefinedCount = redefinedCount;
2827 }
2828 }
2829
2830 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2831
2832 // Incremented by the VM on each call to JVM TI RedefineClasses()
2833 // that redefines this class or a superclass.
2834 private transient volatile int classRedefinedCount;
2835
2836 // Lazily create and cache ReflectionData
2837 private ReflectionData<T> reflectionData() {
2838 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2839 int classRedefinedCount = this.classRedefinedCount;
2840 ReflectionData<T> rd;
2841 if (reflectionData != null &&
2842 (rd = reflectionData.get()) != null &&
2843 rd.redefinedCount == classRedefinedCount) {
2844 return rd;
2845 }
2846 // else no SoftReference or cleared SoftReference or stale ReflectionData
2847 // -> create and replace new instance
2848 return newReflectionData(reflectionData, classRedefinedCount);
2849 }
2850
2851 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2852 int classRedefinedCount) {
2853 while (true) {
2854 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2855 // try to CAS it...
2856 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
2857 return rd;
2858 }
2859 // else retry
2860 oldReflectionData = this.reflectionData;
2861 classRedefinedCount = this.classRedefinedCount;
2862 if (oldReflectionData != null &&
2863 (rd = oldReflectionData.get()) != null &&
2864 rd.redefinedCount == classRedefinedCount) {
2865 return rd;
2866 }
2867 }
2868 }
2869
2870 // Generic signature handling
2871 private native String getGenericSignature0();
2872
2873 // Generic info repository; lazily initialized
2874 private transient volatile ClassRepository genericInfo;
2875
2876 // accessor for factory
2877 private GenericsFactory getFactory() {
2878 // create scope and factory
2879 return CoreReflectionFactory.make(this, ClassScope.make(this));
2880 }
2881
2882 // accessor for generic info repository;
2883 // generic info is lazily initialized
2884 private ClassRepository getGenericInfo() {
2885 ClassRepository genericInfo = this.genericInfo;
2886 if (genericInfo == null) {
2887 String signature = getGenericSignature0();
2888 if (signature == null) {
2889 genericInfo = ClassRepository.NONE;
2890 } else {
2891 genericInfo = ClassRepository.make(signature, getFactory());
2892 }
2893 this.genericInfo = genericInfo;
2894 }
2895 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2896 }
2897
2898 // Annotations handling
2899 native byte[] getRawAnnotations();
2900 // Since 1.8
2901 native byte[] getRawTypeAnnotations();
2902 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2903 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2904 }
2905
2906 native ConstantPool getConstantPool();
2907
2908 //
2909 //
2910 // java.lang.reflect.Field handling
2911 //
2912 //
2913
2914 // Returns an array of "root" fields. These Field objects must NOT
2915 // be propagated to the outside world, but must instead be copied
2916 // via ReflectionFactory.copyField.
2917 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2918 Field[] res;
2919 ReflectionData<T> rd = reflectionData();
2920 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2921 if (res != null) return res;
2922 // No cached value available; request value from VM
2923 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2924 if (publicOnly) {
2925 rd.declaredPublicFields = res;
2926 } else {
2927 rd.declaredFields = res;
2928 }
2929 return res;
2930 }
2931
2932 // Returns an array of "root" fields. These Field objects must NOT
2933 // be propagated to the outside world, but must instead be copied
2934 // via ReflectionFactory.copyField.
2935 private Field[] privateGetPublicFields() {
2936 Field[] res;
2937 ReflectionData<T> rd = reflectionData();
2938 res = rd.publicFields;
2939 if (res != null) return res;
2940
2941 // Use a linked hash set to ensure order is preserved and
2942 // fields from common super interfaces are not duplicated
2943 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2944
2945 // Local fields
2946 addAll(fields, privateGetDeclaredFields(true));
2947
2948 // Direct superinterfaces, recursively
2949 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2950 addAll(fields, si.privateGetPublicFields());
2951 }
2952
2953 // Direct superclass, recursively
2954 Class<?> sc = getSuperclass();
2955 if (sc != null) {
2956 addAll(fields, sc.privateGetPublicFields());
2957 }
2958
2959 res = fields.toArray(new Field[0]);
2960 rd.publicFields = res;
2961 return res;
2962 }
2963
2964 private static void addAll(Collection<Field> c, Field[] o) {
2965 for (Field f : o) {
2966 c.add(f);
2967 }
2968 }
2969
2970
2971 //
2972 //
2973 // java.lang.reflect.Constructor handling
2974 //
2975 //
2976
2977 // Returns an array of "root" constructors. These Constructor
2978 // objects must NOT be propagated to the outside world, but must
2979 // instead be copied via ReflectionFactory.copyConstructor.
2980 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
2981 Constructor<T>[] res;
2982 ReflectionData<T> rd = reflectionData();
2983 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
2984 if (res != null) return res;
2985 // No cached value available; request value from VM
2986 if (isInterface()) {
2987 @SuppressWarnings("unchecked")
2988 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
2989 res = temporaryRes;
2990 } else {
2991 res = getDeclaredConstructors0(publicOnly);
2992 }
2993 if (publicOnly) {
2994 rd.publicConstructors = res;
2995 } else {
2996 rd.declaredConstructors = res;
2997 }
2998 return res;
2999 }
3000
3001 //
3002 //
3003 // java.lang.reflect.Method handling
3004 //
3005 //
3006
3007 // Returns an array of "root" methods. These Method objects must NOT
3008 // be propagated to the outside world, but must instead be copied
3009 // via ReflectionFactory.copyMethod.
3010 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3011 Method[] res;
3012 ReflectionData<T> rd = reflectionData();
3013 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3014 if (res != null) return res;
3015 // No cached value available; request value from VM
3016 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3017 if (publicOnly) {
3018 rd.declaredPublicMethods = res;
3019 } else {
3020 rd.declaredMethods = res;
3021 }
3022 return res;
3023 }
3024
3025 // Returns an array of "root" methods. These Method objects must NOT
3026 // be propagated to the outside world, but must instead be copied
3027 // via ReflectionFactory.copyMethod.
3028 private Method[] privateGetPublicMethods() {
3029 Method[] res;
3030 ReflectionData<T> rd = reflectionData();
3031 res = rd.publicMethods;
3032 if (res != null) return res;
3033
3034 // No cached value available; compute value recursively.
3035 // Start by fetching public declared methods...
3036 PublicMethods pms = new PublicMethods();
3037 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3038 pms.merge(m);
3039 }
3040 // ...then recur over superclass methods...
3041 Class<?> sc = getSuperclass();
3042 if (sc != null) {
3043 for (Method m : sc.privateGetPublicMethods()) {
3044 pms.merge(m);
3045 }
3046 }
3047 // ...and finally over direct superinterfaces.
3048 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3049 for (Method m : intf.privateGetPublicMethods()) {
3050 // static interface methods are not inherited
3051 if (!Modifier.isStatic(m.getModifiers())) {
3052 pms.merge(m);
3053 }
3054 }
3055 }
3056
3057 res = pms.toArray();
3058 rd.publicMethods = res;
3059 return res;
3060 }
3061
3062
3063 //
3064 // Helpers for fetchers of one field, method, or constructor
3065 //
3066
3067 // This method does not copy the returned Field object!
3068 private static Field searchFields(Field[] fields, String name) {
3069 for (Field field : fields) {
3070 if (field.getName().equals(name)) {
3071 return field;
3072 }
3073 }
3074 return null;
3075 }
3076
3077 // Returns a "root" Field object. This Field object must NOT
3078 // be propagated to the outside world, but must instead be copied
3079 // via ReflectionFactory.copyField.
3080 private Field getField0(String name) {
3081 // Note: the intent is that the search algorithm this routine
3082 // uses be equivalent to the ordering imposed by
3083 // privateGetPublicFields(). It fetches only the declared
3084 // public fields for each class, however, to reduce the number
3085 // of Field objects which have to be created for the common
3086 // case where the field being requested is declared in the
3087 // class which is being queried.
3088 Field res;
3089 // Search declared public fields
3090 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3091 return res;
3092 }
3093 // Direct superinterfaces, recursively
3094 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3095 for (Class<?> c : interfaces) {
3096 if ((res = c.getField0(name)) != null) {
3097 return res;
3098 }
3099 }
3100 // Direct superclass, recursively
3101 if (!isInterface()) {
3102 Class<?> c = getSuperclass();
3103 if (c != null) {
3104 if ((res = c.getField0(name)) != null) {
3105 return res;
3106 }
3107 }
3108 }
3109 return null;
3110 }
3111
3112 // This method does not copy the returned Method object!
3113 private static Method searchMethods(Method[] methods,
3114 String name,
3115 Class<?>[] parameterTypes)
3116 {
3117 ReflectionFactory fact = getReflectionFactory();
3118 Method res = null;
3119 for (Method m : methods) {
3120 if (m.getName().equals(name)
3121 && arrayContentsEq(parameterTypes,
3122 fact.getExecutableSharedParameterTypes(m))
3123 && (res == null
3124 || (res.getReturnType() != m.getReturnType()
3125 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3126 res = m;
3127 }
3128 return res;
3129 }
3130
3131 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3132
3133 // Returns a "root" Method object. This Method object must NOT
3134 // be propagated to the outside world, but must instead be copied
3135 // via ReflectionFactory.copyMethod.
3136 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3137 PublicMethods.MethodList res = getMethodsRecursive(
3138 name,
3139 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3140 /* includeStatic */ true, /* publicOnly */ true);
3141 return res == null ? null : res.getMostSpecific();
3142 }
3143
3144 // Returns a list of "root" Method objects. These Method objects must NOT
3145 // be propagated to the outside world, but must instead be copied
3146 // via ReflectionFactory.copyMethod.
3147 private PublicMethods.MethodList getMethodsRecursive(String name,
3148 Class<?>[] parameterTypes,
3149 boolean includeStatic,
3150 boolean publicOnly) {
3151 // 1st check declared methods
3152 Method[] methods = privateGetDeclaredMethods(publicOnly);
3153 PublicMethods.MethodList res = PublicMethods.MethodList
3154 .filter(methods, name, parameterTypes, includeStatic);
3155 // if there is at least one match among declared methods, we need not
3156 // search any further as such match surely overrides matching methods
3157 // declared in superclass(es) or interface(s).
3158 if (res != null) {
3159 return res;
3160 }
3161
3162 // if there was no match among declared methods,
3163 // we must consult the superclass (if any) recursively...
3164 Class<?> sc = getSuperclass();
3165 if (sc != null) {
3166 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3167 }
3168
3169 // ...and coalesce the superclass methods with methods obtained
3170 // from directly implemented interfaces excluding static methods...
3171 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3172 res = PublicMethods.MethodList.merge(
3173 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3174 }
3175
3176 return res;
3177 }
3178
3179 // Returns a "root" Constructor object. This Constructor object must NOT
3180 // be propagated to the outside world, but must instead be copied
3181 // via ReflectionFactory.copyConstructor.
3182 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3183 int which) throws NoSuchMethodException
3184 {
3185 ReflectionFactory fact = getReflectionFactory();
3186 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3187 for (Constructor<T> constructor : constructors) {
3188 if (arrayContentsEq(parameterTypes,
3189 fact.getExecutableSharedParameterTypes(constructor))) {
3190 return constructor;
3191 }
3192 }
3193 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3194 }
3195
3196 //
3197 // Other helpers and base implementation
3198 //
3199
3200 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3201 if (a1 == null) {
3202 return a2 == null || a2.length == 0;
3203 }
3204
3205 if (a2 == null) {
3206 return a1.length == 0;
3207 }
3208
3209 if (a1.length != a2.length) {
3210 return false;
3211 }
3212
3213 for (int i = 0; i < a1.length; i++) {
3214 if (a1[i] != a2[i]) {
3215 return false;
3216 }
3217 }
3218
3219 return true;
3220 }
3221
3222 private static Field[] copyFields(Field[] arg) {
3223 Field[] out = new Field[arg.length];
3224 ReflectionFactory fact = getReflectionFactory();
3225 for (int i = 0; i < arg.length; i++) {
3226 out[i] = fact.copyField(arg[i]);
3227 }
3228 return out;
3229 }
3230
3231 private static Method[] copyMethods(Method[] arg) {
3232 Method[] out = new Method[arg.length];
3233 ReflectionFactory fact = getReflectionFactory();
3234 for (int i = 0; i < arg.length; i++) {
3235 out[i] = fact.copyMethod(arg[i]);
3236 }
3237 return out;
3238 }
3239
3240 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3241 Constructor<U>[] out = arg.clone();
3242 ReflectionFactory fact = getReflectionFactory();
3243 for (int i = 0; i < out.length; i++) {
3244 out[i] = fact.copyConstructor(out[i]);
3245 }
3246 return out;
3247 }
3248
3249 private native Field[] getDeclaredFields0(boolean publicOnly);
3250 private native Method[] getDeclaredMethods0(boolean publicOnly);
3251 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3252 private native Class<?>[] getDeclaredClasses0();
3253
3254 /*
3255 * Returns an array containing the components of the Record attribute,
3256 * or null if the attribute is not present.
3257 *
3258 * Note that this method returns non-null array on a class with
3259 * the Record attribute even if this class is not a record.
3260 */
3261 private native RecordComponent[] getRecordComponents0();
3262 private native boolean isRecord0();
3263
3264 /**
3265 * Helper method to get the method name from arguments.
3266 */
3267 private String methodToString(String name, Class<?>[] argTypes) {
3268 return getName() + '.' + name +
3269 ((argTypes == null || argTypes.length == 0) ?
3270 "()" :
3271 Arrays.stream(argTypes)
3272 .map(c -> c == null ? "null" : c.getName())
3273 .collect(Collectors.joining(",", "(", ")")));
3274 }
3275
3276 /** use serialVersionUID from JDK 1.1 for interoperability */
3277 @java.io.Serial
3278 private static final long serialVersionUID = 3206093459760846163L;
3279
3280
3281 /**
3282 * Class Class is special cased within the Serialization Stream Protocol.
3283 *
3284 * A Class instance is written initially into an ObjectOutputStream in the
3285 * following format:
3286 * <pre>
3287 * {@code TC_CLASS} ClassDescriptor
3288 * A ClassDescriptor is a special cased serialization of
3289 * a {@code java.io.ObjectStreamClass} instance.
3290 * </pre>
3291 * A new handle is generated for the initial time the class descriptor
3292 * is written into the stream. Future references to the class descriptor
3293 * are written as references to the initial class descriptor instance.
3294 *
3295 * @see java.io.ObjectStreamClass
3296 */
3297 @java.io.Serial
3298 private static final ObjectStreamField[] serialPersistentFields =
3299 new ObjectStreamField[0];
3300
3301
3302 /**
3303 * Returns the assertion status that would be assigned to this
3304 * class if it were to be initialized at the time this method is invoked.
3305 * If this class has had its assertion status set, the most recent
3306 * setting will be returned; otherwise, if any package default assertion
3307 * status pertains to this class, the most recent setting for the most
3308 * specific pertinent package default assertion status is returned;
3309 * otherwise, if this class is not a system class (i.e., it has a
3310 * class loader) its class loader's default assertion status is returned;
3311 * otherwise, the system class default assertion status is returned.
3312 *
3313 * @apiNote
3314 * Few programmers will have any need for this method; it is provided
3315 * for the benefit of the JDK itself. (It allows a class to determine at
3316 * the time that it is initialized whether assertions should be enabled.)
3317 * Note that this method is not guaranteed to return the actual
3318 * assertion status that was (or will be) associated with the specified
3319 * class when it was (or will be) initialized.
3320 *
3321 * @return the desired assertion status of the specified class.
3322 * @see java.lang.ClassLoader#setClassAssertionStatus
3323 * @see java.lang.ClassLoader#setPackageAssertionStatus
3324 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3325 * @since 1.4
3326 */
3327 public boolean desiredAssertionStatus() {
3328 ClassLoader loader = classLoader;
3329 // If the loader is null this is a system class, so ask the VM
3330 if (loader == null)
3331 return desiredAssertionStatus0(this);
3332
3333 // If the classloader has been initialized with the assertion
3334 // directives, ask it. Otherwise, ask the VM.
3335 synchronized(loader.assertionLock) {
3336 if (loader.classAssertionStatus != null) {
3337 return loader.desiredAssertionStatus(getName());
3338 }
3339 }
3340 return desiredAssertionStatus0(this);
3341 }
3342
3343 // Retrieves the desired assertion status of this class from the VM
3344 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3345
3346 /**
3347 * Returns true if and only if this class was declared as an enum in the
3348 * source code.
3349 *
3350 * Note that {@link java.lang.Enum} is not itself an enum class.
3351 *
3352 * Also note that if an enum constant is declared with a class body,
3353 * the class of that enum constant object is an anonymous class
3354 * and <em>not</em> the class of the declaring enum class. The
3355 * {@link Enum#getDeclaringClass} method of an enum constant can
3356 * be used to get the class of the enum class declaring the
3357 * constant.
3358 *
3359 * @return true if and only if this class was declared as an enum in the
3360 * source code
3361 * @since 1.5
3362 * @jls 8.9.1 Enum Constants
3363 */
3364 public boolean isEnum() {
3365 // An enum must both directly extend java.lang.Enum and have
3366 // the ENUM bit set; classes for specialized enum constants
3367 // don't do the former.
3368 return (this.getModifiers() & ENUM) != 0 &&
3369 this.getSuperclass() == java.lang.Enum.class;
3370 }
3371
3372 /**
3373 * Returns {@code true} if and only if this class is a record class.
3374 *
3375 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3376 * class is {@code java.lang.Record}. A record class is {@linkplain
3377 * Modifier#FINAL final}. A record class has (possibly zero) record
3378 * components; {@link #getRecordComponents()} returns a non-null but
3379 * possibly empty value for a record.
3380 *
3381 * <p> Note that class {@link Record} is not a record class and thus
3382 * invoking this method on class {@code Record} returns {@code false}.
3383 *
3384 * @return true if and only if this class is a record class, otherwise false
3385 * @jls 8.10 Record Classes
3386 * @since 16
3387 */
3388 public boolean isRecord() {
3389 // this superclass and final modifier check is not strictly necessary
3390 // they are intrinsified and serve as a fast-path check
3391 return getSuperclass() == java.lang.Record.class &&
3392 (this.getModifiers() & Modifier.FINAL) != 0 &&
3393 isRecord0();
3394 }
3395
3396 // Fetches the factory for reflective objects
3397 private static ReflectionFactory getReflectionFactory() {
3398 var factory = reflectionFactory;
3399 if (factory != null) {
3400 return factory;
3401 }
3402 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3403 }
3404 private static ReflectionFactory reflectionFactory;
3405
3406 /**
3407 * When CDS is enabled, the Class class may be aot-initialized. However,
3408 * we can't archive reflectionFactory, so we reset it to null, so it
3409 * will be allocated again at runtime.
3410 */
3411 private static void resetArchivedStates() {
3412 reflectionFactory = null;
3413 }
3414
3415 /**
3416 * Returns the elements of this enum class or null if this
3417 * Class object does not represent an enum class.
3418 *
3419 * @return an array containing the values comprising the enum class
3420 * represented by this {@code Class} object in the order they're
3421 * declared, or null if this {@code Class} object does not
3422 * represent an enum class
3423 * @since 1.5
3424 * @jls 8.9.1 Enum Constants
3425 */
3426 public T[] getEnumConstants() {
3427 T[] values = getEnumConstantsShared();
3428 return (values != null) ? values.clone() : null;
3429 }
3430
3431 /**
3432 * Returns the elements of this enum class or null if this
3433 * Class object does not represent an enum class;
3434 * identical to getEnumConstants except that the result is
3435 * uncloned, cached, and shared by all callers.
3436 */
3437 T[] getEnumConstantsShared() {
3438 T[] constants = enumConstants;
3439 if (constants == null) {
3440 if (!isEnum()) return null;
3441 try {
3442 final Method values = getMethod("values");
3443 values.setAccessible(true);
3444 @SuppressWarnings("unchecked")
3445 T[] temporaryConstants = (T[])values.invoke(null);
3446 enumConstants = constants = temporaryConstants;
3447 }
3448 // These can happen when users concoct enum-like classes
3449 // that don't comply with the enum spec.
3450 catch (InvocationTargetException | NoSuchMethodException |
3451 IllegalAccessException | NullPointerException |
3452 ClassCastException ex) { return null; }
3453 }
3454 return constants;
3455 }
3456 private transient volatile T[] enumConstants;
3457
3458 /**
3459 * Returns a map from simple name to enum constant. This package-private
3460 * method is used internally by Enum to implement
3461 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3462 * efficiently. Note that the map is returned by this method is
3463 * created lazily on first use. Typically it won't ever get created.
3464 */
3465 Map<String, T> enumConstantDirectory() {
3466 Map<String, T> directory = enumConstantDirectory;
3467 if (directory == null) {
3468 T[] universe = getEnumConstantsShared();
3469 if (universe == null)
3470 throw new IllegalArgumentException(
3471 getName() + " is not an enum class");
3472 directory = HashMap.newHashMap(universe.length);
3473 for (T constant : universe) {
3474 directory.put(((Enum<?>)constant).name(), constant);
3475 }
3476 enumConstantDirectory = directory;
3477 }
3478 return directory;
3479 }
3480 private transient volatile Map<String, T> enumConstantDirectory;
3481
3482 /**
3483 * Casts an object to the class or interface represented
3484 * by this {@code Class} object.
3485 *
3486 * @param obj the object to be cast
3487 * @return the object after casting, or null if obj is null
3488 *
3489 * @throws ClassCastException if the object is not
3490 * null and is not assignable to the type T.
3491 *
3492 * @since 1.5
3493 */
3494 @SuppressWarnings("unchecked")
3495 @IntrinsicCandidate
3496 public T cast(Object obj) {
3497 if (obj != null && !isInstance(obj))
3498 throw new ClassCastException(cannotCastMsg(obj));
3499 return (T) obj;
3500 }
3501
3502 private String cannotCastMsg(Object obj) {
3503 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3504 }
3505
3506 /**
3507 * Casts this {@code Class} object to represent a subclass of the class
3508 * represented by the specified class object. Checks that the cast
3509 * is valid, and throws a {@code ClassCastException} if it is not. If
3510 * this method succeeds, it always returns a reference to this {@code Class} object.
3511 *
3512 * <p>This method is useful when a client needs to "narrow" the type of
3513 * a {@code Class} object to pass it to an API that restricts the
3514 * {@code Class} objects that it is willing to accept. A cast would
3515 * generate a compile-time warning, as the correctness of the cast
3516 * could not be checked at runtime (because generic types are implemented
3517 * by erasure).
3518 *
3519 * @param <U> the type to cast this {@code Class} object to
3520 * @param clazz the class of the type to cast this {@code Class} object to
3521 * @return this {@code Class} object, cast to represent a subclass of
3522 * the specified class object.
3523 * @throws ClassCastException if this {@code Class} object does not
3524 * represent a subclass of the specified class (here "subclass" includes
3525 * the class itself).
3526 * @since 1.5
3527 */
3528 @SuppressWarnings("unchecked")
3529 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3530 if (clazz.isAssignableFrom(this))
3531 return (Class<? extends U>) this;
3532 else
3533 throw new ClassCastException(this.toString());
3534 }
3535
3536 /**
3537 * {@inheritDoc}
3538 * <p>Note that any annotation returned by this method is a
3539 * declaration annotation.
3540 *
3541 * @throws NullPointerException {@inheritDoc}
3542 * @since 1.5
3543 */
3544 @Override
3545 @SuppressWarnings("unchecked")
3546 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3547 Objects.requireNonNull(annotationClass);
3548
3549 return (A) annotationData().annotations.get(annotationClass);
3550 }
3551
3552 /**
3553 * {@inheritDoc}
3554 * @throws NullPointerException {@inheritDoc}
3555 * @since 1.5
3556 */
3557 @Override
3558 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3559 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3560 }
3561
3562 /**
3563 * {@inheritDoc}
3564 * <p>Note that any annotations returned by this method are
3565 * declaration annotations.
3566 *
3567 * @throws NullPointerException {@inheritDoc}
3568 * @since 1.8
3569 */
3570 @Override
3571 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3572 Objects.requireNonNull(annotationClass);
3573
3574 AnnotationData annotationData = annotationData();
3575 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3576 this,
3577 annotationClass);
3578 }
3579
3580 /**
3581 * {@inheritDoc}
3582 * <p>Note that any annotations returned by this method are
3583 * declaration annotations.
3584 *
3585 * @since 1.5
3586 */
3587 @Override
3588 public Annotation[] getAnnotations() {
3589 return AnnotationParser.toArray(annotationData().annotations);
3590 }
3591
3592 /**
3593 * {@inheritDoc}
3594 * <p>Note that any annotation returned by this method is a
3595 * declaration annotation.
3596 *
3597 * @throws NullPointerException {@inheritDoc}
3598 * @since 1.8
3599 */
3600 @Override
3601 @SuppressWarnings("unchecked")
3602 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3603 Objects.requireNonNull(annotationClass);
3604
3605 return (A) annotationData().declaredAnnotations.get(annotationClass);
3606 }
3607
3608 /**
3609 * {@inheritDoc}
3610 * <p>Note that any annotations returned by this method are
3611 * declaration annotations.
3612 *
3613 * @throws NullPointerException {@inheritDoc}
3614 * @since 1.8
3615 */
3616 @Override
3617 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3618 Objects.requireNonNull(annotationClass);
3619
3620 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3621 annotationClass);
3622 }
3623
3624 /**
3625 * {@inheritDoc}
3626 * <p>Note that any annotations returned by this method are
3627 * declaration annotations.
3628 *
3629 * @since 1.5
3630 */
3631 @Override
3632 public Annotation[] getDeclaredAnnotations() {
3633 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3634 }
3635
3636 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3637 private static class AnnotationData {
3638 final Map<Class<? extends Annotation>, Annotation> annotations;
3639 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3640
3641 // Value of classRedefinedCount when we created this AnnotationData instance
3642 final int redefinedCount;
3643
3644 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3645 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3646 int redefinedCount) {
3647 this.annotations = annotations;
3648 this.declaredAnnotations = declaredAnnotations;
3649 this.redefinedCount = redefinedCount;
3650 }
3651 }
3652
3653 // Annotations cache
3654 @SuppressWarnings("UnusedDeclaration")
3655 private transient volatile AnnotationData annotationData;
3656
3657 private AnnotationData annotationData() {
3658 while (true) { // retry loop
3659 AnnotationData annotationData = this.annotationData;
3660 int classRedefinedCount = this.classRedefinedCount;
3661 if (annotationData != null &&
3662 annotationData.redefinedCount == classRedefinedCount) {
3663 return annotationData;
3664 }
3665 // null or stale annotationData -> optimistically create new instance
3666 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3667 // try to install it
3668 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3669 // successfully installed new AnnotationData
3670 return newAnnotationData;
3671 }
3672 }
3673 }
3674
3675 private AnnotationData createAnnotationData(int classRedefinedCount) {
3676 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3677 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3678 Class<?> superClass = getSuperclass();
3679 Map<Class<? extends Annotation>, Annotation> annotations = null;
3680 if (superClass != null) {
3681 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3682 superClass.annotationData().annotations;
3683 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3684 Class<? extends Annotation> annotationClass = e.getKey();
3685 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3686 if (annotations == null) { // lazy construction
3687 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3688 declaredAnnotations.size(),
3689 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3690 )
3691 );
3692 }
3693 annotations.put(annotationClass, e.getValue());
3694 }
3695 }
3696 }
3697 if (annotations == null) {
3698 // no inherited annotations -> share the Map with declaredAnnotations
3699 annotations = declaredAnnotations;
3700 } else {
3701 // at least one inherited annotation -> declared may override inherited
3702 annotations.putAll(declaredAnnotations);
3703 }
3704 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3705 }
3706
3707 // Annotation interfaces cache their internal (AnnotationType) form
3708
3709 @SuppressWarnings("UnusedDeclaration")
3710 private transient volatile AnnotationType annotationType;
3711
3712 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3713 return Atomic.casAnnotationType(this, oldType, newType);
3714 }
3715
3716 AnnotationType getAnnotationType() {
3717 return annotationType;
3718 }
3719
3720 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3721 return annotationData().declaredAnnotations;
3722 }
3723
3724 /* Backing store of user-defined values pertaining to this class.
3725 * Maintained by the ClassValue class.
3726 */
3727 transient ClassValue.ClassValueMap classValueMap;
3728
3729 /**
3730 * Returns an {@code AnnotatedType} object that represents the use of a
3731 * type to specify the superclass of the entity represented by this {@code
3732 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3733 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3734 * Foo.)
3735 *
3736 * <p> If this {@code Class} object represents a class whose declaration
3737 * does not explicitly indicate an annotated superclass, then the return
3738 * value is an {@code AnnotatedType} object representing an element with no
3739 * annotations.
3740 *
3741 * <p> If this {@code Class} represents either the {@code Object} class, an
3742 * interface type, an array type, a primitive type, or void, the return
3743 * value is {@code null}.
3744 *
3745 * @return an object representing the superclass
3746 * @since 1.8
3747 */
3748 public AnnotatedType getAnnotatedSuperclass() {
3749 if (this == Object.class ||
3750 isInterface() ||
3751 isArray() ||
3752 isPrimitive() ||
3753 this == Void.TYPE) {
3754 return null;
3755 }
3756
3757 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3758 }
3759
3760 /**
3761 * Returns an array of {@code AnnotatedType} objects that represent the use
3762 * of types to specify superinterfaces of the entity represented by this
3763 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3764 * superinterface in '... implements Foo' is distinct from the
3765 * <em>declaration</em> of interface Foo.)
3766 *
3767 * <p> If this {@code Class} object represents a class, the return value is
3768 * an array containing objects representing the uses of interface types to
3769 * specify interfaces implemented by the class. The order of the objects in
3770 * the array corresponds to the order of the interface types used in the
3771 * 'implements' clause of the declaration of this {@code Class} object.
3772 *
3773 * <p> If this {@code Class} object represents an interface, the return
3774 * value is an array containing objects representing the uses of interface
3775 * types to specify interfaces directly extended by the interface. The
3776 * order of the objects in the array corresponds to the order of the
3777 * interface types used in the 'extends' clause of the declaration of this
3778 * {@code Class} object.
3779 *
3780 * <p> If this {@code Class} object represents a class or interface whose
3781 * declaration does not explicitly indicate any annotated superinterfaces,
3782 * the return value is an array of length 0.
3783 *
3784 * <p> If this {@code Class} object represents either the {@code Object}
3785 * class, an array type, a primitive type, or void, the return value is an
3786 * array of length 0.
3787 *
3788 * @return an array representing the superinterfaces
3789 * @since 1.8
3790 */
3791 public AnnotatedType[] getAnnotatedInterfaces() {
3792 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3793 }
3794
3795 private native Class<?> getNestHost0();
3796
3797 /**
3798 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3799 * or interface represented by this {@code Class} object belongs.
3800 * Every class and interface belongs to exactly one nest.
3801 *
3802 * If the nest host of this class or interface has previously
3803 * been determined, then this method returns the nest host.
3804 * If the nest host of this class or interface has
3805 * not previously been determined, then this method determines the nest
3806 * host using the algorithm of JVMS 5.4.4, and returns it.
3807 *
3808 * Often, a class or interface belongs to a nest consisting only of itself,
3809 * in which case this method returns {@code this} to indicate that the class
3810 * or interface is the nest host.
3811 *
3812 * <p>If this {@code Class} object represents a primitive type, an array type,
3813 * or {@code void}, then this method returns {@code this},
3814 * indicating that the represented entity belongs to the nest consisting only of
3815 * itself, and is the nest host.
3816 *
3817 * @return the nest host of this class or interface
3818 *
3819 * @since 11
3820 * @jvms 4.7.28 The {@code NestHost} Attribute
3821 * @jvms 4.7.29 The {@code NestMembers} Attribute
3822 * @jvms 5.4.4 Access Control
3823 */
3824 public Class<?> getNestHost() {
3825 if (isPrimitive() || isArray()) {
3826 return this;
3827 }
3828 return getNestHost0();
3829 }
3830
3831 /**
3832 * Determines if the given {@code Class} is a nestmate of the
3833 * class or interface represented by this {@code Class} object.
3834 * Two classes or interfaces are nestmates
3835 * if they have the same {@linkplain #getNestHost() nest host}.
3836 *
3837 * @param c the class to check
3838 * @return {@code true} if this class and {@code c} are members of
3839 * the same nest; and {@code false} otherwise.
3840 *
3841 * @since 11
3842 */
3843 public boolean isNestmateOf(Class<?> c) {
3844 if (this == c) {
3845 return true;
3846 }
3847 if (isPrimitive() || isArray() ||
3848 c.isPrimitive() || c.isArray()) {
3849 return false;
3850 }
3851
3852 return getNestHost() == c.getNestHost();
3853 }
3854
3855 private native Class<?>[] getNestMembers0();
3856
3857 /**
3858 * Returns an array containing {@code Class} objects representing all the
3859 * classes and interfaces that are members of the nest to which the class
3860 * or interface represented by this {@code Class} object belongs.
3861 *
3862 * First, this method obtains the {@linkplain #getNestHost() nest host},
3863 * {@code H}, of the nest to which the class or interface represented by
3864 * this {@code Class} object belongs. The zeroth element of the returned
3865 * array is {@code H}.
3866 *
3867 * Then, for each class or interface {@code C} which is recorded by {@code H}
3868 * as being a member of its nest, this method attempts to obtain the {@code Class}
3869 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3870 * loader} of the current {@code Class} object), and then obtains the
3871 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3872 * The classes and interfaces which are recorded by {@code H} as being members
3873 * of its nest, and for which {@code H} can be determined as their nest host,
3874 * are indicated by subsequent elements of the returned array. The order of
3875 * such elements is unspecified. Duplicates are permitted.
3876 *
3877 * <p>If this {@code Class} object represents a primitive type, an array type,
3878 * or {@code void}, then this method returns a single-element array containing
3879 * {@code this}.
3880 *
3881 * @apiNote
3882 * The returned array includes only the nest members recorded in the {@code NestMembers}
3883 * attribute, and not any hidden classes that were added to the nest via
3884 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3885 * Lookup::defineHiddenClass}.
3886 *
3887 * @return an array of all classes and interfaces in the same nest as
3888 * this class or interface
3889 *
3890 * @since 11
3891 * @see #getNestHost()
3892 * @jvms 4.7.28 The {@code NestHost} Attribute
3893 * @jvms 4.7.29 The {@code NestMembers} Attribute
3894 */
3895 public Class<?>[] getNestMembers() {
3896 if (isPrimitive() || isArray()) {
3897 return new Class<?>[] { this };
3898 }
3899 Class<?>[] members = getNestMembers0();
3900 // Can't actually enable this due to bootstrapping issues
3901 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3902 return members;
3903 }
3904
3905 /**
3906 * Returns the descriptor string of the entity (class, interface, array class,
3907 * primitive type, or {@code void}) represented by this {@code Class} object.
3908 *
3909 * <p> If this {@code Class} object represents a class or interface,
3910 * not an array class, then:
3911 * <ul>
3912 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3913 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3914 * for the class or interface. Calling
3915 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3916 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3917 * describing this class or interface.
3918 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3919 * then the result is a string of the form:
3920 * <blockquote>
3921 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3922 * </blockquote>
3923 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3924 * encoded in internal form indicated by the {@code class} file passed to
3925 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3926 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3927 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3928 * The result string is not a type descriptor.
3929 * </ul>
3930 *
3931 * <p> If this {@code Class} object represents an array class, then
3932 * the result is a string consisting of one or more '{@code [}' characters
3933 * representing the depth of the array nesting, followed by the
3934 * descriptor string of the element type.
3935 * <ul>
3936 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3937 * or interface, then this array class can be described nominally.
3938 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3939 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3940 * describing this array class.
3941 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3942 * interface, then this array class cannot be described nominally.
3943 * The result string is not a type descriptor.
3944 * </ul>
3945 *
3946 * <p> If this {@code Class} object represents a primitive type or
3947 * {@code void}, then the result is a field descriptor string which
3948 * is a one-letter code corresponding to a primitive type or {@code void}
3949 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3950 *
3951 * @return the descriptor string for this {@code Class} object
3952 * @jvms 4.3.2 Field Descriptors
3953 * @since 12
3954 */
3955 @Override
3956 public String descriptorString() {
3957 if (isPrimitive())
3958 return Wrapper.forPrimitiveType(this).basicTypeString();
3959
3960 if (isArray()) {
3961 return "[".concat(componentType.descriptorString());
3962 } else if (isHidden()) {
3963 String name = getName();
3964 int index = name.indexOf('/');
3965 return new StringBuilder(name.length() + 2)
3966 .append('L')
3967 .append(name.substring(0, index).replace('.', '/'))
3968 .append('.')
3969 .append(name, index + 1, name.length())
3970 .append(';')
3971 .toString();
3972 } else {
3973 String name = getName().replace('.', '/');
3974 return StringConcatHelper.concat("L", name, ";");
3975 }
3976 }
3977
3978 /**
3979 * Returns the component type of this {@code Class}, if it describes
3980 * an array type, or {@code null} otherwise.
3981 *
3982 * @implSpec
3983 * Equivalent to {@link Class#getComponentType()}.
3984 *
3985 * @return a {@code Class} describing the component type, or {@code null}
3986 * if this {@code Class} does not describe an array type
3987 * @since 12
3988 */
3989 @Override
3990 public Class<?> componentType() {
3991 return isArray() ? componentType : null;
3992 }
3993
3994 /**
3995 * Returns a {@code Class} for an array type whose component type
3996 * is described by this {@linkplain Class}.
3997 *
3998 * @throws UnsupportedOperationException if this component type is {@linkplain
3999 * Void#TYPE void} or if the number of dimensions of the resulting array
4000 * type would exceed 255.
4001 * @return a {@code Class} describing the array type
4002 * @jvms 4.3.2 Field Descriptors
4003 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4004 * @since 12
4005 */
4006 @Override
4007 public Class<?> arrayType() {
4008 try {
4009 return Array.newInstance(this, 0).getClass();
4010 } catch (IllegalArgumentException iae) {
4011 throw new UnsupportedOperationException(iae);
4012 }
4013 }
4014
4015 /**
4016 * Returns a nominal descriptor for this instance, if one can be
4017 * constructed, or an empty {@link Optional} if one cannot be.
4018 *
4019 * @return An {@link Optional} containing the resulting nominal descriptor,
4020 * or an empty {@link Optional} if one cannot be constructed.
4021 * @since 12
4022 */
4023 @Override
4024 public Optional<ClassDesc> describeConstable() {
4025 Class<?> c = isArray() ? elementType() : this;
4026 return c.isHidden() ? Optional.empty()
4027 : Optional.of(ConstantUtils.classDesc(this));
4028 }
4029
4030 /**
4031 * Returns {@code true} if and only if the underlying class is a hidden class.
4032 *
4033 * @return {@code true} if and only if this class is a hidden class.
4034 *
4035 * @since 15
4036 * @see MethodHandles.Lookup#defineHiddenClass
4037 * @see Class##hiddenClasses Hidden Classes
4038 */
4039 @IntrinsicCandidate
4040 public native boolean isHidden();
4041
4042 /**
4043 * Returns an array containing {@code Class} objects representing the
4044 * direct subinterfaces or subclasses permitted to extend or
4045 * implement this class or interface if it is sealed. The order of such elements
4046 * is unspecified. The array is empty if this sealed class or interface has no
4047 * permitted subclass. If this {@code Class} object represents a primitive type,
4048 * {@code void}, an array type, or a class or interface that is not sealed,
4049 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4050 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4051 * returns a non-null value.
4052 *
4053 * For each class or interface {@code C} which is recorded as a permitted
4054 * direct subinterface or subclass of this class or interface,
4055 * this method attempts to obtain the {@code Class}
4056 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4057 * loader} of the current {@code Class} object).
4058 * The {@code Class} objects which can be obtained and which are direct
4059 * subinterfaces or subclasses of this class or interface,
4060 * are indicated by elements of the returned array. If a {@code Class} object
4061 * cannot be obtained, it is silently ignored, and not included in the result
4062 * array.
4063 *
4064 * @return an array of {@code Class} objects of the permitted subclasses of this class
4065 * or interface, or {@code null} if this class or interface is not sealed.
4066 *
4067 * @jls 8.1 Class Declarations
4068 * @jls 9.1 Interface Declarations
4069 * @since 17
4070 */
4071 public Class<?>[] getPermittedSubclasses() {
4072 Class<?>[] subClasses;
4073 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4074 return null;
4075 }
4076 if (subClasses.length > 0) {
4077 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4078 subClasses = Arrays.stream(subClasses)
4079 .filter(this::isDirectSubType)
4080 .toArray(s -> new Class<?>[s]);
4081 }
4082 }
4083 return subClasses;
4084 }
4085
4086 private boolean isDirectSubType(Class<?> c) {
4087 if (isInterface()) {
4088 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4089 if (i == this) {
4090 return true;
4091 }
4092 }
4093 } else {
4094 return c.getSuperclass() == this;
4095 }
4096 return false;
4097 }
4098
4099 /**
4100 * Returns {@code true} if and only if this {@code Class} object represents
4101 * a sealed class or interface. If this {@code Class} object represents a
4102 * primitive type, {@code void}, or an array type, this method returns
4103 * {@code false}. A sealed class or interface has (possibly zero) permitted
4104 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4105 * possibly empty value for a sealed class or interface.
4106 *
4107 * @return {@code true} if and only if this {@code Class} object represents
4108 * a sealed class or interface.
4109 *
4110 * @jls 8.1 Class Declarations
4111 * @jls 9.1 Interface Declarations
4112 * @since 17
4113 */
4114 public boolean isSealed() {
4115 if (isArray() || isPrimitive()) {
4116 return false;
4117 }
4118 return getPermittedSubclasses() != null;
4119 }
4120
4121 private native Class<?>[] getPermittedSubclasses0();
4122
4123 /*
4124 * Return the class's major and minor class file version packed into an int.
4125 * The high order 16 bits contain the class's minor version. The low order
4126 * 16 bits contain the class's major version.
4127 *
4128 * If the class is an array type then the class file version of its element
4129 * type is returned. If the class is a primitive type then the latest class
4130 * file major version is returned and zero is returned for the minor version.
4131 */
4132 private int getClassFileVersion() {
4133 Class<?> c = isArray() ? elementType() : this;
4134 return c.getClassFileVersion0();
4135 }
4136
4137 private native int getClassFileVersion0();
4138
4139 /*
4140 * Return the access flags as they were in the class's bytecode, including
4141 * the original setting of ACC_SUPER.
4142 *
4143 * If the class is an array type then the access flags of the element type is
4144 * returned. If the class is a primitive then ACC_ABSTRACT | ACC_FINAL | ACC_PUBLIC.
4145 */
4146 private int getClassAccessFlagsRaw() {
4147 Class<?> c = isArray() ? elementType() : this;
4148 return c.getClassAccessFlagsRaw0();
4149 }
4150
4151 private native int getClassAccessFlagsRaw0();
4152 }