1 /*
2 * Copyright (c) 1994, 2024, 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.Permissions;
57 import java.security.ProtectionDomain;
58 import java.util.ArrayList;
59 import java.util.Arrays;
60 import java.util.Collection;
61 import java.util.HashMap;
62 import java.util.HashSet;
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.security.util.SecurityConstants;
93 import sun.reflect.annotation.*;
94 import sun.reflect.misc.ReflectUtil;
95
96 /**
97 * Instances of the class {@code Class} represent classes and
98 * interfaces in a running Java application. An enum class and a record
99 * class are kinds of class; an annotation interface is a kind of
100 * interface. Every array also belongs to a class that is reflected as
101 * a {@code Class} object that is shared by all arrays with the same
102 * element type and number of dimensions. The primitive Java types
103 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
104 * int}, {@code long}, {@code float}, and {@code double}), and the
105 * keyword {@code void} are also represented as {@code Class} objects.
106 *
107 * <p> {@code Class} has no public constructor. Instead a {@code Class}
108 * object is constructed automatically by the Java Virtual Machine when
109 * a class is derived from the bytes of a {@code class} file through
110 * the invocation of one of the following methods:
111 * <ul>
112 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
113 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
114 * java.lang.invoke.MethodHandles.Lookup::defineClass}
115 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
116 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
117 * </ul>
118 *
119 * <p> The methods of class {@code Class} expose many characteristics of a
120 * class or interface. Most characteristics are derived from the {@code class}
121 * file that the class loader passed to the Java Virtual Machine or
122 * from the {@code class} file passed to {@code Lookup::defineClass}
123 * or {@code Lookup::defineHiddenClass}.
124 * A few characteristics are determined by the class loading environment
125 * at run time, such as the module returned by {@link #getModule() getModule()}.
126 *
127 * <p> The following example uses a {@code Class} object to print the
128 * class name of an object:
129 *
130 * {@snippet lang="java" :
131 * void printClassName(Object obj) {
132 * System.out.println("The class of " + obj +
133 * " is " + obj.getClass().getName());
134 * }}
135 *
136 * It is also possible to get the {@code Class} object for a named
137 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
138 * (JLS {@jls 15.8.2}).
139 * For example:
140 *
141 * {@snippet lang="java" :
142 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
143 * }
144 *
145 * <p> Some methods of class {@code Class} expose whether the declaration of
146 * a class or interface in Java source code was <em>enclosed</em> within
147 * another declaration. Other methods describe how a class or interface
148 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
149 * classes and interfaces, in the same run-time package, that
150 * allow mutual access to their {@code private} members.
151 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
152 * (JVMS {@jvms 4.7.29}).
153 * One nestmate acts as the
154 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
155 * belong to the nest; each of them in turn records it as the nest host.
156 * The classes and interfaces which belong to a nest, including its host, are
157 * determined when
158 * {@code class} files are generated, for example, a Java compiler
159 * will typically record a top-level class as the host of a nest where the
160 * other members are the classes and interfaces whose declarations are
161 * enclosed within the top-level class declaration.
162 *
163 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
164 * A class or interface created by the invocation of
165 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
166 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
167 * class or interface.
168 * All kinds of class, including enum classes and record classes, may be
169 * hidden classes; all kinds of interface, including annotation interfaces,
170 * may be hidden interfaces.
171 *
172 * The {@linkplain #getName() name of a hidden class or interface} is
173 * not a {@linkplain ClassLoader##binary-name binary name},
174 * which means the following:
175 * <ul>
176 * <li>A hidden class or interface cannot be referenced by the constant pools
177 * of other classes and interfaces.
178 * <li>A hidden class or interface cannot be described in
179 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
180 * {@link #describeConstable() Class::describeConstable},
181 * {@link ClassDesc#of(String) ClassDesc::of}, or
182 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
183 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
184 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
185 * </ul>
186 *
187 * A hidden class or interface is never an array class, but may be
188 * the element type of an array. In all other respects, the fact that
189 * a class or interface is hidden has no bearing on the characteristics
190 * exposed by the methods of class {@code Class}.
191 *
192 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
193 *
194 * Conventionally, a Java compiler, starting from a source file for an
195 * implicitly declared class, say {@code HelloWorld.java}, creates a
196 * similarly-named {@code class} file, {@code HelloWorld.class}, where
197 * the class stored in that {@code class} file is named {@code
198 * "HelloWorld"}, matching the base names of the source and {@code
199 * class} files.
200 *
201 * For the {@code Class} object of an implicitly declared class {@code
202 * HelloWorld}, the methods to get the {@linkplain #getName name} and
203 * {@linkplain #getTypeName type name} return results
204 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
205 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
206 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
207 *
208 * @param <T> the type of the class modeled by this {@code Class}
209 * object. For example, the type of {@code String.class} is {@code
210 * Class<String>}. Use {@code Class<?>} if the class being modeled is
211 * unknown.
212 *
213 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
214 * @since 1.0
215 */
216 public final class Class<T> implements java.io.Serializable,
217 GenericDeclaration,
218 Type,
219 AnnotatedElement,
220 TypeDescriptor.OfField<Class<?>>,
221 Constable {
222 private static final int ANNOTATION= 0x00002000;
223 private static final int ENUM = 0x00004000;
224 private static final int SYNTHETIC = 0x00001000;
225
226 private static native void registerNatives();
227 static {
228 runtimeSetup();
229 }
230
231 // Called from JVM when loading an AOT cache
232 private static void runtimeSetup() {
233 registerNatives();
234 }
235
236 /*
237 * Private constructor. Only the Java Virtual Machine creates Class objects.
238 * This constructor is not used and prevents the default constructor being
239 * generated.
240 */
241 private Class(ClassLoader loader, Class<?> arrayComponentType) {
242 // Initialize final field for classLoader. The initialization value of non-null
243 // prevents future JIT optimizations from assuming this final field is null.
244 classLoader = loader;
245 componentType = arrayComponentType;
246 }
247
248 /**
249 * Converts the object to a string. The string representation is the
250 * string "class" or "interface", followed by a space, and then by the
251 * name of the class in the format returned by {@code getName}.
252 * If this {@code Class} object represents a primitive type,
253 * this method returns the name of the primitive type. If
254 * this {@code Class} object represents void this method returns
255 * "void". If this {@code Class} object represents an array type,
256 * this method returns "class " followed by {@code getName}.
257 *
258 * @return a string representation of this {@code Class} object.
259 */
260 public String toString() {
261 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
262 return kind.concat(getName());
263 }
264
265 /**
266 * Returns a string describing this {@code Class}, including
267 * information about modifiers, {@link #isSealed() sealed}/{@code
268 * non-sealed} status, and type parameters.
269 *
270 * The string is formatted as a list of type modifiers, if any,
271 * followed by the kind of type (empty string for primitive types
272 * and {@code class}, {@code enum}, {@code interface},
273 * {@code @interface}, or {@code record} as appropriate), followed
274 * by the type's name, followed by an angle-bracketed
275 * comma-separated list of the type's type parameters, if any,
276 * including informative bounds on the type parameters, if any.
277 *
278 * A space is used to separate modifiers from one another and to
279 * separate any modifiers from the kind of type. The modifiers
280 * occur in canonical order. If there are no type parameters, the
281 * type parameter list is elided.
282 *
283 * For an array type, the string starts with the type name,
284 * followed by an angle-bracketed comma-separated list of the
285 * type's type parameters, if any, followed by a sequence of
286 * {@code []} characters, one set of brackets per dimension of
287 * the array.
288 *
289 * <p>Note that since information about the runtime representation
290 * of a type is being generated, modifiers not present on the
291 * originating source code or illegal on the originating source
292 * code may be present.
293 *
294 * @return a string describing this {@code Class}, including
295 * information about modifiers and type parameters
296 *
297 * @since 1.8
298 */
299 public String toGenericString() {
300 if (isPrimitive()) {
301 return toString();
302 } else {
303 StringBuilder sb = new StringBuilder();
304 Class<?> component = this;
305 int arrayDepth = 0;
306
307 if (isArray()) {
308 do {
309 arrayDepth++;
310 component = component.getComponentType();
311 } while (component.isArray());
312 sb.append(component.getName());
313 } else {
314 // Class modifiers are a superset of interface modifiers
315 int modifiers = getModifiers() & Modifier.classModifiers();
316 if (modifiers != 0) {
317 sb.append(Modifier.toString(modifiers));
318 sb.append(' ');
319 }
320
321 // A class cannot be strictfp and sealed/non-sealed so
322 // it is sufficient to check for sealed-ness after all
323 // modifiers are printed.
324 addSealingInfo(modifiers, sb);
325
326 if (isAnnotation()) {
327 sb.append('@');
328 }
329 if (isInterface()) { // Note: all annotation interfaces are interfaces
330 sb.append("interface");
331 } else {
332 if (isEnum())
333 sb.append("enum");
334 else if (isRecord())
335 sb.append("record");
336 else
337 sb.append("class");
338 }
339 sb.append(' ');
340 sb.append(getName());
341 }
342
343 TypeVariable<?>[] typeparms = component.getTypeParameters();
344 if (typeparms.length > 0) {
345 sb.append(Arrays.stream(typeparms)
346 .map(Class::typeVarBounds)
347 .collect(Collectors.joining(",", "<", ">")));
348 }
349
350 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
351
352 return sb.toString();
353 }
354 }
355
356 private void addSealingInfo(int modifiers, StringBuilder sb) {
357 // A class can be final XOR sealed XOR non-sealed.
358 if (Modifier.isFinal(modifiers)) {
359 return; // no-op
360 } else {
361 if (isSealed()) {
362 sb.append("sealed ");
363 return;
364 } else {
365 // Check for sealed ancestor, which implies this class
366 // is non-sealed.
367 if (hasSealedAncestor(this)) {
368 sb.append("non-sealed ");
369 }
370 }
371 }
372 }
373
374 private boolean hasSealedAncestor(Class<?> clazz) {
375 // From JLS 8.1.1.2:
376 // "It is a compile-time error if a class has a sealed direct
377 // superclass or a sealed direct superinterface, and is not
378 // declared final, sealed, or non-sealed either explicitly or
379 // implicitly.
380 // Thus, an effect of the sealed keyword is to force all
381 // direct subclasses to explicitly declare whether they are
382 // final, sealed, or non-sealed. This avoids accidentally
383 // exposing a sealed class hierarchy to unwanted subclassing."
384
385 // Therefore, will just check direct superclass and
386 // superinterfaces.
387 var superclass = clazz.getSuperclass();
388 if (superclass != null && superclass.isSealed()) {
389 return true;
390 }
391 for (var superinterface : clazz.getInterfaces()) {
392 if (superinterface.isSealed()) {
393 return true;
394 }
395 }
396 return false;
397 }
398
399 static String typeVarBounds(TypeVariable<?> typeVar) {
400 Type[] bounds = typeVar.getBounds();
401 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
402 return typeVar.getName();
403 } else {
404 return typeVar.getName() + " extends " +
405 Arrays.stream(bounds)
406 .map(Type::getTypeName)
407 .collect(Collectors.joining(" & "));
408 }
409 }
410
411 /**
412 * Returns the {@code Class} object associated with the class or
413 * interface with the given string name. Invoking this method is
414 * equivalent to:
415 *
416 * {@snippet lang="java" :
417 * Class.forName(className, true, currentLoader)
418 * }
419 *
420 * where {@code currentLoader} denotes the defining class loader of
421 * the current class.
422 *
423 * <p> For example, the following code fragment returns the
424 * runtime {@code Class} object for the class named
425 * {@code java.lang.Thread}:
426 *
427 * {@snippet lang="java" :
428 * Class<?> t = Class.forName("java.lang.Thread");
429 * }
430 * <p>
431 * A call to {@code forName("X")} causes the class named
432 * {@code X} to be initialized.
433 *
434 * <p>
435 * In cases where this method is called from a context where there is no
436 * caller frame on the stack (e.g. when called directly from a JNI
437 * attached thread), the system class loader is used.
438 *
439 * @param className the {@linkplain ClassLoader##binary-name binary name}
440 * of the class or the string representing an array type
441 * @return the {@code Class} object for the class with the
442 * specified name.
443 * @throws LinkageError if the linkage fails
444 * @throws ExceptionInInitializerError if the initialization provoked
445 * by this method fails
446 * @throws ClassNotFoundException if the class cannot be located
447 *
448 * @jls 12.2 Loading of Classes and Interfaces
449 * @jls 12.3 Linking of Classes and Interfaces
450 * @jls 12.4 Initialization of Classes and Interfaces
451 */
452 @CallerSensitive
453 public static Class<?> forName(String className)
454 throws ClassNotFoundException {
455 Class<?> caller = Reflection.getCallerClass();
456 return forName(className, caller);
457 }
458
459 // Caller-sensitive adapter method for reflective invocation
460 @CallerSensitiveAdapter
461 private static Class<?> forName(String className, Class<?> caller)
462 throws ClassNotFoundException {
463 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
464 : ClassLoader.getClassLoader(caller);
465 return forName0(className, true, loader, caller);
466 }
467
468 /**
469 * Returns the {@code Class} object associated with the class or
470 * interface with the given string name, using the given class loader.
471 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
472 * this method attempts to locate and load the class or interface. The specified
473 * class loader is used to load the class or interface. If the parameter
474 * {@code loader} is {@code null}, the class is loaded through the bootstrap
475 * class loader. The class is initialized only if the
476 * {@code initialize} parameter is {@code true} and if it has
477 * not been initialized earlier.
478 *
479 * <p> This method cannot be used to obtain any of the {@code Class} objects
480 * representing primitive types or void, hidden classes or interfaces,
481 * or array classes whose element type is a hidden class or interface.
482 * If {@code name} denotes a primitive type or void, for example {@code I},
483 * an attempt will be made to locate a user-defined class in the unnamed package
484 * whose name is {@code I} instead.
485 * To obtain a {@code Class} object for a named primitive type
486 * such as {@code int} or {@code long} use {@link
487 * #forPrimitiveName(String)}.
488 *
489 * <p> To obtain the {@code Class} object associated with an array class,
490 * the name consists of one or more {@code '['} representing the depth
491 * of the array nesting, followed by the element type as encoded in
492 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
493 *
494 * <p> Examples:
495 * {@snippet lang="java" :
496 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
497 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
498 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
499 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
500 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
501 * }
502 *
503 * <p> A call to {@code getName()} on the {@code Class} object returned
504 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
505 *
506 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
507 * named <i>N</i> to be loaded but not initialized regardless of the value
508 * of the {@code initialize} parameter.
509 *
510 * @apiNote
511 * This method throws errors related to loading, linking or initializing
512 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
513 * <cite>The Java Language Specification</cite>.
514 * In addition, this method does not check whether the requested class
515 * is accessible to its caller.
516 *
517 * @param name the {@linkplain ClassLoader##binary-name binary name}
518 * of the class or the string representing an array class
519 *
520 * @param initialize if {@code true} the class will be initialized
521 * (which implies linking). See Section {@jls
522 * 12.4} of <cite>The Java Language
523 * Specification</cite>.
524 * @param loader class loader from which the class must be loaded
525 * @return class object representing the desired class
526 *
527 * @throws LinkageError if the linkage fails
528 * @throws ExceptionInInitializerError if the initialization provoked
529 * by this method fails
530 * @throws ClassNotFoundException if the class cannot be located by
531 * the specified class loader
532 *
533 * @see java.lang.Class#forName(String)
534 * @see java.lang.ClassLoader
535 *
536 * @jls 12.2 Loading of Classes and Interfaces
537 * @jls 12.3 Linking of Classes and Interfaces
538 * @jls 12.4 Initialization of Classes and Interfaces
539 * @jls 13.1 The Form of a Binary
540 * @since 1.2
541 */
542 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
543 throws ClassNotFoundException
544 {
545 return forName0(name, initialize, loader, null);
546 }
547
548 /** Called after security check for system loader access checks have been made. */
549 private static native Class<?> forName0(String name, boolean initialize,
550 ClassLoader loader,
551 Class<?> caller)
552 throws ClassNotFoundException;
553
554
555 /**
556 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
557 * binary name} in the given module.
558 *
559 * <p> This method attempts to locate and load the class or interface.
560 * It does not link the class, and does not run the class initializer.
561 * If the class is not found, this method returns {@code null}. </p>
562 *
563 * <p> If the class loader of the given module defines other modules and
564 * the given name is a class defined in a different module, this method
565 * returns {@code null} after the class is loaded. </p>
566 *
567 * <p> This method does not check whether the requested class is
568 * accessible to its caller. </p>
569 *
570 * @apiNote
571 * This method does not support loading of array types, unlike
572 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
573 * a binary name. This method returns {@code null} on failure rather than
574 * throwing a {@link ClassNotFoundException}, as is done by
575 * the {@link #forName(String, boolean, ClassLoader)} method.
576 *
577 * @param module A module
578 * @param name The {@linkplain ClassLoader##binary-name binary name}
579 * of the class
580 * @return {@code Class} object of the given name defined in the given module;
581 * {@code null} if not found.
582 *
583 * @throws NullPointerException if the given module or name is {@code null}
584 *
585 * @throws LinkageError if the linkage fails
586 *
587 * @jls 12.2 Loading of Classes and Interfaces
588 * @jls 12.3 Linking of Classes and Interfaces
589 * @since 9
590 */
591 public static Class<?> forName(Module module, String name) {
592 Objects.requireNonNull(module);
593 Objects.requireNonNull(name);
594
595 ClassLoader cl = module.getClassLoader();
596 if (cl != null) {
597 return cl.loadClass(module, name);
598 } else {
599 return BootLoader.loadClass(module, name);
600 }
601 }
602
603 /**
604 * {@return the {@code Class} object associated with the
605 * {@linkplain #isPrimitive() primitive type} of the given name}
606 * If the argument is not the name of a primitive type, {@code
607 * null} is returned.
608 *
609 * @param primitiveName the name of the primitive type to find
610 *
611 * @throws NullPointerException if the argument is {@code null}
612 *
613 * @jls 4.2 Primitive Types and Values
614 * @jls 15.8.2 Class Literals
615 * @since 22
616 */
617 public static Class<?> forPrimitiveName(String primitiveName) {
618 return switch(primitiveName) {
619 // Integral types
620 case "int" -> int.class;
621 case "long" -> long.class;
622 case "short" -> short.class;
623 case "char" -> char.class;
624 case "byte" -> byte.class;
625
626 // Floating-point types
627 case "float" -> float.class;
628 case "double" -> double.class;
629
630 // Other types
631 case "boolean" -> boolean.class;
632 case "void" -> void.class;
633
634 default -> null;
635 };
636 }
637
638 /**
639 * Creates a new instance of the class represented by this {@code Class}
640 * object. The class is instantiated as if by a {@code new}
641 * expression with an empty argument list. The class is initialized if it
642 * has not already been initialized.
643 *
644 * @deprecated This method propagates any exception thrown by the
645 * nullary constructor, including a checked exception. Use of
646 * this method effectively bypasses the compile-time exception
647 * checking that would otherwise be performed by the compiler.
648 * The {@link
649 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
650 * Constructor.newInstance} method avoids this problem by wrapping
651 * any exception thrown by the constructor in a (checked) {@link
652 * java.lang.reflect.InvocationTargetException}.
653 *
654 * <p>The call
655 *
656 * {@snippet lang="java" :
657 * clazz.newInstance()
658 * }
659 *
660 * can be replaced by
661 *
662 * {@snippet lang="java" :
663 * clazz.getDeclaredConstructor().newInstance()
664 * }
665 *
666 * The latter sequence of calls is inferred to be able to throw
667 * the additional exception types {@link
668 * InvocationTargetException} and {@link
669 * NoSuchMethodException}. Both of these exception types are
670 * subclasses of {@link ReflectiveOperationException}.
671 *
672 * @return a newly allocated instance of the class represented by this
673 * object.
674 * @throws IllegalAccessException if the class or its nullary
675 * constructor is not accessible.
676 * @throws InstantiationException
677 * if this {@code Class} represents an abstract class,
678 * an interface, an array class, a primitive type, or void;
679 * or if the class has no nullary constructor;
680 * or if the instantiation fails for some other reason.
681 * @throws ExceptionInInitializerError if the initialization
682 * provoked by this method fails.
683 */
684 @CallerSensitive
685 @Deprecated(since="9")
686 public T newInstance()
687 throws InstantiationException, IllegalAccessException
688 {
689 // Constructor lookup
690 Constructor<T> tmpConstructor = cachedConstructor;
691 if (tmpConstructor == null) {
692 if (this == Class.class) {
693 throw new IllegalAccessException(
694 "Can not call newInstance() on the Class for java.lang.Class"
695 );
696 }
697 try {
698 Class<?>[] empty = {};
699 final Constructor<T> c = getReflectionFactory().copyConstructor(
700 getConstructor0(empty, Member.DECLARED));
701 // Disable accessibility checks on the constructor
702 // access check is done with the true caller
703 c.setAccessible(true);
704 cachedConstructor = tmpConstructor = c;
705 } catch (NoSuchMethodException e) {
706 throw (InstantiationException)
707 new InstantiationException(getName()).initCause(e);
708 }
709 }
710
711 try {
712 Class<?> caller = Reflection.getCallerClass();
713 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
714 } catch (InvocationTargetException e) {
715 Unsafe.getUnsafe().throwException(e.getTargetException());
716 // Not reached
717 return null;
718 }
719 }
720
721 private transient volatile Constructor<T> cachedConstructor;
722
723 /**
724 * Determines if the specified {@code Object} is assignment-compatible
725 * with the object represented by this {@code Class}. This method is
726 * the dynamic equivalent of the Java language {@code instanceof}
727 * operator. The method returns {@code true} if the specified
728 * {@code Object} argument is non-null and can be cast to the
729 * reference type represented by this {@code Class} object without
730 * raising a {@code ClassCastException.} It returns {@code false}
731 * otherwise.
732 *
733 * <p> Specifically, if this {@code Class} object represents a
734 * declared class, this method returns {@code true} if the specified
735 * {@code Object} argument is an instance of the represented class (or
736 * of any of its subclasses); it returns {@code false} otherwise. If
737 * this {@code Class} object represents an array class, this method
738 * returns {@code true} if the specified {@code Object} argument
739 * can be converted to an object of the array class by an identity
740 * conversion or by a widening reference conversion; it returns
741 * {@code false} otherwise. If this {@code Class} object
742 * represents an interface, this method returns {@code true} if the
743 * class or any superclass of the specified {@code Object} argument
744 * implements this interface; it returns {@code false} otherwise. If
745 * this {@code Class} object represents a primitive type, this method
746 * returns {@code false}.
747 *
748 * @param obj the object to check
749 * @return true if {@code obj} is an instance of this class
750 *
751 * @since 1.1
752 */
753 @IntrinsicCandidate
754 public native boolean isInstance(Object obj);
755
756
757 /**
758 * Determines if the class or interface represented by this
759 * {@code Class} object is either the same as, or is a superclass or
760 * superinterface of, the class or interface represented by the specified
761 * {@code Class} parameter. It returns {@code true} if so;
762 * otherwise it returns {@code false}. If this {@code Class}
763 * object represents a primitive type, this method returns
764 * {@code true} if the specified {@code Class} parameter is
765 * exactly this {@code Class} object; otherwise it returns
766 * {@code false}.
767 *
768 * <p> Specifically, this method tests whether the type represented by the
769 * specified {@code Class} parameter can be converted to the type
770 * represented by this {@code Class} object via an identity conversion
771 * or via a widening reference conversion. See <cite>The Java Language
772 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
773 * for details.
774 *
775 * @param cls the {@code Class} object to be checked
776 * @return the {@code boolean} value indicating whether objects of the
777 * type {@code cls} can be assigned to objects of this class
778 * @throws NullPointerException if the specified Class parameter is
779 * null.
780 * @since 1.1
781 */
782 @IntrinsicCandidate
783 public native boolean isAssignableFrom(Class<?> cls);
784
785
786 /**
787 * Determines if this {@code Class} object represents an
788 * interface type.
789 *
790 * @return {@code true} if this {@code Class} object represents an interface;
791 * {@code false} otherwise.
792 */
793 @IntrinsicCandidate
794 public native boolean isInterface();
795
796
797 /**
798 * Determines if this {@code Class} object represents an array class.
799 *
800 * @return {@code true} if this {@code Class} object represents an array class;
801 * {@code false} otherwise.
802 * @since 1.1
803 */
804 @IntrinsicCandidate
805 public native boolean isArray();
806
807
808 /**
809 * Determines if this {@code Class} object represents a primitive
810 * type or void.
811 *
812 * <p> There are nine predefined {@code Class} objects to
813 * represent the eight primitive types and void. These are
814 * created by the Java Virtual Machine, and have the same
815 * {@linkplain #getName() names} as the primitive types that they
816 * represent, namely {@code boolean}, {@code byte}, {@code char},
817 * {@code short}, {@code int}, {@code long}, {@code float}, and
818 * {@code double}.
819 *
820 * <p>No other class objects are considered primitive.
821 *
822 * @apiNote
823 * A {@code Class} object represented by a primitive type can be
824 * accessed via the {@code TYPE} public static final variables
825 * defined in the primitive wrapper classes such as {@link
826 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
827 * language, the objects may be referred to by a class literal
828 * expression such as {@code int.class}. The {@code Class} object
829 * for void can be expressed as {@code void.class} or {@link
830 * java.lang.Void#TYPE Void.TYPE}.
831 *
832 * @return true if and only if this class represents a primitive type
833 *
834 * @see java.lang.Boolean#TYPE
835 * @see java.lang.Character#TYPE
836 * @see java.lang.Byte#TYPE
837 * @see java.lang.Short#TYPE
838 * @see java.lang.Integer#TYPE
839 * @see java.lang.Long#TYPE
840 * @see java.lang.Float#TYPE
841 * @see java.lang.Double#TYPE
842 * @see java.lang.Void#TYPE
843 * @since 1.1
844 * @jls 15.8.2 Class Literals
845 */
846 @IntrinsicCandidate
847 public native boolean isPrimitive();
848
849 /**
850 * Returns true if this {@code Class} object represents an annotation
851 * interface. Note that if this method returns true, {@link #isInterface()}
852 * would also return true, as all annotation interfaces are also interfaces.
853 *
854 * @return {@code true} if this {@code Class} object represents an annotation
855 * interface; {@code false} otherwise
856 * @since 1.5
857 */
858 public boolean isAnnotation() {
859 return (getModifiers() & ANNOTATION) != 0;
860 }
861
862 /**
863 *{@return {@code true} if and only if this class has the synthetic modifier
864 * bit set}
865 *
866 * @jls 13.1 The Form of a Binary
867 * @jvms 4.1 The {@code ClassFile} Structure
868 * @see <a
869 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
870 * programming language and JVM modeling in core reflection</a>
871 * @since 1.5
872 */
873 public boolean isSynthetic() {
874 return (getModifiers() & SYNTHETIC) != 0;
875 }
876
877 /**
878 * Returns the name of the entity (class, interface, array class,
879 * primitive type, or void) represented by this {@code Class} object.
880 *
881 * <p> If this {@code Class} object represents a class or interface,
882 * not an array class, then:
883 * <ul>
884 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
885 * then the {@linkplain ClassLoader##binary-name binary name}
886 * of the class or interface is returned.
887 * <li> If the class or interface is hidden, then the result is a string
888 * of the form: {@code N + '/' + <suffix>}
889 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
890 * indicated by the {@code class} file passed to
891 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
892 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
893 * </ul>
894 *
895 * <p> If this {@code Class} object represents an array class, then
896 * the result is a string consisting of one or more '{@code [}' characters
897 * representing the depth of the array nesting, followed by the element
898 * type as encoded using the following table:
899 *
900 * <blockquote><table class="striped" id="nameFormat">
901 * <caption style="display:none">Element types and encodings</caption>
902 * <thead>
903 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
904 * </thead>
905 * <tbody style="text-align:left">
906 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
907 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
908 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
909 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
910 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
911 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
912 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
913 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
914 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
915 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
916 * </tbody>
917 * </table></blockquote>
918 *
919 * <p> If this {@code Class} object represents a primitive type or {@code void},
920 * then the result is a string with the same spelling as the Java language
921 * keyword which corresponds to the primitive type or {@code void}.
922 *
923 * <p> Examples:
924 * <blockquote><pre>
925 * String.class.getName()
926 * returns "java.lang.String"
927 * Character.UnicodeBlock.class.getName()
928 * returns "java.lang.Character$UnicodeBlock"
929 * byte.class.getName()
930 * returns "byte"
931 * (new Object[3]).getClass().getName()
932 * returns "[Ljava.lang.Object;"
933 * (new int[3][4][5][6][7][8][9]).getClass().getName()
934 * returns "[[[[[[[I"
935 * </pre></blockquote>
936 *
937 * @apiNote
938 * Distinct class objects can have the same name but different class loaders.
939 *
940 * @return the name of the class, interface, or other entity
941 * represented by this {@code Class} object.
942 * @jls 13.1 The Form of a Binary
943 */
944 public String getName() {
945 String name = this.name;
946 return name != null ? name : initClassName();
947 }
948
949 // Cache the name to reduce the number of calls into the VM.
950 // This field would be set by VM itself during initClassName call.
951 private transient String name;
952 private native String initClassName();
953
954 /**
955 * Returns the class loader for the class. Some implementations may use
956 * null to represent the bootstrap class loader. This method will return
957 * null in such implementations if this class was loaded by the bootstrap
958 * class loader.
959 *
960 * <p>If this {@code Class} object
961 * represents a primitive type or void, null is returned.
962 *
963 * @return the class loader that loaded the class or interface
964 * represented by this {@code Class} object.
965 * @see java.lang.ClassLoader
966 */
967 public ClassLoader getClassLoader() {
968 return classLoader;
969 }
970
971 // Package-private to allow ClassLoader access
972 ClassLoader getClassLoader0() { return classLoader; }
973
974 /**
975 * Returns the module that this class or interface is a member of.
976 *
977 * If this class represents an array type then this method returns the
978 * {@code Module} for the element type. If this class represents a
979 * primitive type or void, then the {@code Module} object for the
980 * {@code java.base} module is returned.
981 *
982 * If this class is in an unnamed module then the {@linkplain
983 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
984 * loader for this class is returned.
985 *
986 * @return the module that this class or interface is a member of
987 *
988 * @since 9
989 */
990 public Module getModule() {
991 return module;
992 }
993
994 // set by VM
995 @Stable
996 private transient Module module;
997
998 // Initialized in JVM not by private constructor
999 // This field is filtered from reflection access, i.e. getDeclaredField
1000 // will throw NoSuchFieldException
1001 private final ClassLoader classLoader;
1002
1003 private transient Object classData; // Set by VM
1004 private transient Object[] signers; // Read by VM, mutable
1005
1006 // package-private
1007 Object getClassData() {
1008 return classData;
1009 }
1010
1011 /**
1012 * Returns an array of {@code TypeVariable} objects that represent the
1013 * type variables declared by the generic declaration represented by this
1014 * {@code GenericDeclaration} object, in declaration order. Returns an
1015 * array of length 0 if the underlying generic declaration declares no type
1016 * variables.
1017 *
1018 * @return an array of {@code TypeVariable} objects that represent
1019 * the type variables declared by this generic declaration
1020 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1021 * signature of this generic declaration does not conform to
1022 * the format specified in section {@jvms 4.7.9} of
1023 * <cite>The Java Virtual Machine Specification</cite>
1024 * @since 1.5
1025 */
1026 @SuppressWarnings("unchecked")
1027 public TypeVariable<Class<T>>[] getTypeParameters() {
1028 ClassRepository info = getGenericInfo();
1029 if (info != null)
1030 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1031 else
1032 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1033 }
1034
1035
1036 /**
1037 * Returns the {@code Class} representing the direct superclass of the
1038 * entity (class, interface, primitive type or void) represented by
1039 * this {@code Class}. If this {@code Class} represents either the
1040 * {@code Object} class, an interface, a primitive type, or void, then
1041 * null is returned. If this {@code Class} object represents an array class
1042 * then the {@code Class} object representing the {@code Object} class is
1043 * returned.
1044 *
1045 * @return the direct superclass of the class represented by this {@code Class} object
1046 */
1047 @IntrinsicCandidate
1048 public native Class<? super T> getSuperclass();
1049
1050
1051 /**
1052 * Returns the {@code Type} representing the direct superclass of
1053 * the entity (class, interface, primitive type or void) represented by
1054 * this {@code Class} object.
1055 *
1056 * <p>If the superclass is a parameterized type, the {@code Type}
1057 * object returned must accurately reflect the actual type
1058 * arguments used in the source code. The parameterized type
1059 * representing the superclass is created if it had not been
1060 * created before. See the declaration of {@link
1061 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1062 * semantics of the creation process for parameterized types. If
1063 * this {@code Class} object represents either the {@code Object}
1064 * class, an interface, a primitive type, or void, then null is
1065 * returned. If this {@code Class} object represents an array class
1066 * then the {@code Class} object representing the {@code Object} class is
1067 * returned.
1068 *
1069 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1070 * class signature does not conform to the format specified in
1071 * section {@jvms 4.7.9} of <cite>The Java Virtual
1072 * Machine Specification</cite>
1073 * @throws TypeNotPresentException if the generic superclass
1074 * refers to a non-existent type declaration
1075 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1076 * generic superclass refers to a parameterized type that cannot be
1077 * instantiated for any reason
1078 * @return the direct superclass of the class represented by this {@code Class} object
1079 * @since 1.5
1080 */
1081 public Type getGenericSuperclass() {
1082 ClassRepository info = getGenericInfo();
1083 if (info == null) {
1084 return getSuperclass();
1085 }
1086
1087 // Historical irregularity:
1088 // Generic signature marks interfaces with superclass = Object
1089 // but this API returns null for interfaces
1090 if (isInterface()) {
1091 return null;
1092 }
1093
1094 return info.getSuperclass();
1095 }
1096
1097 /**
1098 * Gets the package of this class.
1099 *
1100 * <p>If this class represents an array type, a primitive type or void,
1101 * this method returns {@code null}.
1102 *
1103 * @return the package of this class.
1104 */
1105 public Package getPackage() {
1106 if (isPrimitive() || isArray()) {
1107 return null;
1108 }
1109 ClassLoader cl = classLoader;
1110 return cl != null ? cl.definePackage(this)
1111 : BootLoader.definePackage(this);
1112 }
1113
1114 /**
1115 * Returns the fully qualified package name.
1116 *
1117 * <p> If this class is a top level class, then this method returns the fully
1118 * qualified name of the package that the class is a member of, or the
1119 * empty string if the class is in an unnamed package.
1120 *
1121 * <p> If this class is a member class, then this method is equivalent to
1122 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1123 * enclosing class}.
1124 *
1125 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1126 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1127 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1128 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1129 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1130 *
1131 * <p> If this class represents an array type then this method returns the
1132 * package name of the element type. If this class represents a primitive
1133 * type or void then the package name "{@code java.lang}" is returned.
1134 *
1135 * @return the fully qualified package name
1136 *
1137 * @since 9
1138 * @jls 6.7 Fully Qualified Names and Canonical Names
1139 */
1140 public String getPackageName() {
1141 String pn = this.packageName;
1142 if (pn == null) {
1143 Class<?> c = isArray() ? elementType() : this;
1144 if (c.isPrimitive()) {
1145 pn = "java.lang";
1146 } else {
1147 String cn = c.getName();
1148 int dot = cn.lastIndexOf('.');
1149 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1150 }
1151 this.packageName = pn;
1152 }
1153 return pn;
1154 }
1155
1156 // cached package name
1157 private transient String packageName;
1158
1159 /**
1160 * Returns the interfaces directly implemented by the class or interface
1161 * represented by this {@code Class} object.
1162 *
1163 * <p>If this {@code Class} object represents a class, the return value is an array
1164 * containing objects representing all interfaces directly implemented by
1165 * the class. The order of the interface objects in the array corresponds
1166 * to the order of the interface names in the {@code implements} clause of
1167 * the declaration of the class represented by this {@code Class} object. For example,
1168 * given the declaration:
1169 * <blockquote>
1170 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1171 * </blockquote>
1172 * suppose the value of {@code s} is an instance of
1173 * {@code Shimmer}; the value of the expression:
1174 * <blockquote>
1175 * {@code s.getClass().getInterfaces()[0]}
1176 * </blockquote>
1177 * is the {@code Class} object that represents interface
1178 * {@code FloorWax}; and the value of:
1179 * <blockquote>
1180 * {@code s.getClass().getInterfaces()[1]}
1181 * </blockquote>
1182 * is the {@code Class} object that represents interface
1183 * {@code DessertTopping}.
1184 *
1185 * <p>If this {@code Class} object represents an interface, the array contains objects
1186 * representing all interfaces directly extended by the interface. The
1187 * order of the interface objects in the array corresponds to the order of
1188 * the interface names in the {@code extends} clause of the declaration of
1189 * the interface represented by this {@code Class} object.
1190 *
1191 * <p>If this {@code Class} object represents a class or interface that implements no
1192 * interfaces, the method returns an array of length 0.
1193 *
1194 * <p>If this {@code Class} object represents a primitive type or void, the method
1195 * returns an array of length 0.
1196 *
1197 * <p>If this {@code Class} object represents an array type, the
1198 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1199 * returned in that order.
1200 *
1201 * @return an array of interfaces directly implemented by this class
1202 */
1203 public Class<?>[] getInterfaces() {
1204 // defensively copy before handing over to user code
1205 return getInterfaces(true);
1206 }
1207
1208 private Class<?>[] getInterfaces(boolean cloneArray) {
1209 ReflectionData<T> rd = reflectionData();
1210 if (rd == null) {
1211 // no cloning required
1212 return getInterfaces0();
1213 } else {
1214 Class<?>[] interfaces = rd.interfaces;
1215 if (interfaces == null) {
1216 interfaces = getInterfaces0();
1217 rd.interfaces = interfaces;
1218 }
1219 // defensively copy if requested
1220 return cloneArray ? interfaces.clone() : interfaces;
1221 }
1222 }
1223
1224 private native Class<?>[] getInterfaces0();
1225
1226 /**
1227 * Returns the {@code Type}s representing the interfaces
1228 * directly implemented by the class or interface represented by
1229 * this {@code Class} object.
1230 *
1231 * <p>If a superinterface is a parameterized type, the
1232 * {@code Type} object returned for it must accurately reflect
1233 * the actual type arguments used in the source code. The
1234 * parameterized type representing each superinterface is created
1235 * if it had not been created before. See the declaration of
1236 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1237 * for the semantics of the creation process for parameterized
1238 * types.
1239 *
1240 * <p>If this {@code Class} object represents a class, the return value is an array
1241 * containing objects representing all interfaces directly implemented by
1242 * the class. The order of the interface objects in the array corresponds
1243 * to the order of the interface names in the {@code implements} clause of
1244 * the declaration of the class represented by this {@code Class} object.
1245 *
1246 * <p>If this {@code Class} object represents an interface, the array contains objects
1247 * representing all interfaces directly extended by the interface. The
1248 * order of the interface objects in the array corresponds to the order of
1249 * the interface names in the {@code extends} clause of the declaration of
1250 * the interface represented by this {@code Class} object.
1251 *
1252 * <p>If this {@code Class} object represents a class or interface that implements no
1253 * interfaces, the method returns an array of length 0.
1254 *
1255 * <p>If this {@code Class} object represents a primitive type or void, the method
1256 * returns an array of length 0.
1257 *
1258 * <p>If this {@code Class} object represents an array type, the
1259 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1260 * returned in that order.
1261 *
1262 * @throws java.lang.reflect.GenericSignatureFormatError
1263 * if the generic class signature does not conform to the
1264 * format specified in section {@jvms 4.7.9} of <cite>The
1265 * Java Virtual Machine Specification</cite>
1266 * @throws TypeNotPresentException if any of the generic
1267 * superinterfaces refers to a non-existent type declaration
1268 * @throws java.lang.reflect.MalformedParameterizedTypeException
1269 * if any of the generic superinterfaces refer to a parameterized
1270 * type that cannot be instantiated for any reason
1271 * @return an array of interfaces directly implemented by this class
1272 * @since 1.5
1273 */
1274 public Type[] getGenericInterfaces() {
1275 ClassRepository info = getGenericInfo();
1276 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1277 }
1278
1279
1280 /**
1281 * Returns the {@code Class} representing the component type of an
1282 * array. If this class does not represent an array class this method
1283 * returns null.
1284 *
1285 * @return the {@code Class} representing the component type of this
1286 * class if this class is an array
1287 * @see java.lang.reflect.Array
1288 * @since 1.1
1289 */
1290 public Class<?> getComponentType() {
1291 // Only return for array types. Storage may be reused for Class for instance types.
1292 if (isArray()) {
1293 return componentType;
1294 } else {
1295 return null;
1296 }
1297 }
1298
1299 private final Class<?> componentType;
1300
1301 /*
1302 * Returns the {@code Class} representing the element type of an array class.
1303 * If this class does not represent an array class, then this method returns
1304 * {@code null}.
1305 */
1306 private Class<?> elementType() {
1307 if (!isArray()) return null;
1308
1309 Class<?> c = this;
1310 while (c.isArray()) {
1311 c = c.getComponentType();
1312 }
1313 return c;
1314 }
1315
1316 /**
1317 * Returns the Java language modifiers for this class or interface, encoded
1318 * in an integer. The modifiers consist of the Java Virtual Machine's
1319 * constants for {@code public}, {@code protected},
1320 * {@code private}, {@code final}, {@code static},
1321 * {@code abstract} and {@code interface}; they should be decoded
1322 * using the methods of class {@code Modifier}.
1323 *
1324 * <p> If the underlying class is an array class:
1325 * <ul>
1326 * <li> its {@code public}, {@code private} and {@code protected}
1327 * modifiers are the same as those of its component type
1328 * <li> its {@code abstract} and {@code final} modifiers are always
1329 * {@code true}
1330 * <li> its interface modifier is always {@code false}, even when
1331 * the component type is an interface
1332 * </ul>
1333 * If this {@code Class} object represents a primitive type or
1334 * void, its {@code public}, {@code abstract}, and {@code final}
1335 * modifiers are always {@code true}.
1336 * For {@code Class} objects representing void, primitive types, and
1337 * arrays, the values of other modifiers are {@code false} other
1338 * than as specified above.
1339 *
1340 * <p> The modifier encodings are defined in section {@jvms 4.1}
1341 * of <cite>The Java Virtual Machine Specification</cite>.
1342 *
1343 * @return the {@code int} representing the modifiers for this class
1344 * @see java.lang.reflect.Modifier
1345 * @see #accessFlags()
1346 * @see <a
1347 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1348 * programming language and JVM modeling in core reflection</a>
1349 * @since 1.1
1350 * @jls 8.1.1 Class Modifiers
1351 * @jls 9.1.1 Interface Modifiers
1352 * @jvms 4.1 The {@code ClassFile} Structure
1353 */
1354 @IntrinsicCandidate
1355 public native int getModifiers();
1356
1357 /**
1358 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1359 * flags} for this class, possibly empty}
1360 *
1361 * <p> If the underlying class is an array class:
1362 * <ul>
1363 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1364 * access flags are the same as those of its component type
1365 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1366 * <li> its {@code INTERFACE} flag is absent, even when the
1367 * component type is an interface
1368 * </ul>
1369 * If this {@code Class} object represents a primitive type or
1370 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1371 * {@code FINAL}.
1372 * For {@code Class} objects representing void, primitive types, and
1373 * arrays, access flags are absent other than as specified above.
1374 *
1375 * @see #getModifiers()
1376 * @jvms 4.1 The ClassFile Structure
1377 * @jvms 4.7.6 The InnerClasses Attribute
1378 * @since 20
1379 */
1380 public Set<AccessFlag> accessFlags() {
1381 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1382 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1383 // and STATIC, which are not allowed on Location.CLASS.
1384 // Use getClassAccessFlagsRaw to expose SUPER status.
1385 var location = (isMemberClass() || isLocalClass() ||
1386 isAnonymousClass() || isArray()) ?
1387 AccessFlag.Location.INNER_CLASS :
1388 AccessFlag.Location.CLASS;
1389 return AccessFlag.maskToAccessFlags((location == AccessFlag.Location.CLASS) ?
1390 getClassAccessFlagsRaw() :
1391 getModifiers(),
1392 location);
1393 }
1394
1395 /**
1396 * Gets the signers of this class.
1397 *
1398 * @return the signers of this class, or null if there are no signers. In
1399 * particular, this method returns null if this {@code Class} object represents
1400 * a primitive type or void.
1401 * @since 1.1
1402 */
1403 public Object[] getSigners() {
1404 var signers = this.signers;
1405 return signers == null ? null : signers.clone();
1406 }
1407
1408 /**
1409 * Set the signers of this class.
1410 */
1411 void setSigners(Object[] signers) {
1412 if (!isPrimitive() && !isArray()) {
1413 this.signers = signers;
1414 }
1415 }
1416
1417 /**
1418 * If this {@code Class} object represents a local or anonymous
1419 * class within a method, returns a {@link
1420 * java.lang.reflect.Method Method} object representing the
1421 * immediately enclosing method of the underlying class. Returns
1422 * {@code null} otherwise.
1423 *
1424 * In particular, this method returns {@code null} if the underlying
1425 * class is a local or anonymous class immediately enclosed by a class or
1426 * interface declaration, instance initializer or static initializer.
1427 *
1428 * @return the immediately enclosing method of the underlying class, if
1429 * that class is a local or anonymous class; otherwise {@code null}.
1430 *
1431 * @since 1.5
1432 */
1433 public Method getEnclosingMethod() {
1434 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1435
1436 if (enclosingInfo == null)
1437 return null;
1438 else {
1439 if (!enclosingInfo.isMethod())
1440 return null;
1441
1442 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1443 getFactory());
1444 Class<?> returnType = toClass(typeInfo.getReturnType());
1445 Type [] parameterTypes = typeInfo.getParameterTypes();
1446 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1447
1448 // Convert Types to Classes; returned types *should*
1449 // be class objects since the methodDescriptor's used
1450 // don't have generics information
1451 for(int i = 0; i < parameterClasses.length; i++)
1452 parameterClasses[i] = toClass(parameterTypes[i]);
1453
1454 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1455 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1456
1457 /*
1458 * Loop over all declared methods; match method name,
1459 * number of and type of parameters, *and* return
1460 * type. Matching return type is also necessary
1461 * because of covariant returns, etc.
1462 */
1463 ReflectionFactory fact = getReflectionFactory();
1464 for (Method m : candidates) {
1465 if (m.getName().equals(enclosingInfo.getName()) &&
1466 arrayContentsEq(parameterClasses,
1467 fact.getExecutableSharedParameterTypes(m))) {
1468 // finally, check return type
1469 if (m.getReturnType().equals(returnType)) {
1470 return fact.copyMethod(m);
1471 }
1472 }
1473 }
1474
1475 throw new InternalError("Enclosing method not found");
1476 }
1477 }
1478
1479 private native Object[] getEnclosingMethod0();
1480
1481 private EnclosingMethodInfo getEnclosingMethodInfo() {
1482 Object[] enclosingInfo = getEnclosingMethod0();
1483 if (enclosingInfo == null)
1484 return null;
1485 else {
1486 return new EnclosingMethodInfo(enclosingInfo);
1487 }
1488 }
1489
1490 private static final class EnclosingMethodInfo {
1491 private final Class<?> enclosingClass;
1492 private final String name;
1493 private final String descriptor;
1494
1495 static void validate(Object[] enclosingInfo) {
1496 if (enclosingInfo.length != 3)
1497 throw new InternalError("Malformed enclosing method information");
1498 try {
1499 // The array is expected to have three elements:
1500
1501 // the immediately enclosing class
1502 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1503 assert(enclosingClass != null);
1504
1505 // the immediately enclosing method or constructor's
1506 // name (can be null).
1507 String name = (String)enclosingInfo[1];
1508
1509 // the immediately enclosing method or constructor's
1510 // descriptor (null iff name is).
1511 String descriptor = (String)enclosingInfo[2];
1512 assert((name != null && descriptor != null) || name == descriptor);
1513 } catch (ClassCastException cce) {
1514 throw new InternalError("Invalid type in enclosing method information", cce);
1515 }
1516 }
1517
1518 EnclosingMethodInfo(Object[] enclosingInfo) {
1519 validate(enclosingInfo);
1520 this.enclosingClass = (Class<?>)enclosingInfo[0];
1521 this.name = (String)enclosingInfo[1];
1522 this.descriptor = (String)enclosingInfo[2];
1523 }
1524
1525 boolean isPartial() {
1526 return enclosingClass == null || name == null || descriptor == null;
1527 }
1528
1529 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1530
1531 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1532
1533 Class<?> getEnclosingClass() { return enclosingClass; }
1534
1535 String getName() { return name; }
1536
1537 String getDescriptor() { return descriptor; }
1538
1539 }
1540
1541 private static Class<?> toClass(Type o) {
1542 if (o instanceof GenericArrayType gat)
1543 return toClass(gat.getGenericComponentType()).arrayType();
1544 return (Class<?>)o;
1545 }
1546
1547 /**
1548 * If this {@code Class} object represents a local or anonymous
1549 * class within a constructor, returns a {@link
1550 * java.lang.reflect.Constructor Constructor} object representing
1551 * the immediately enclosing constructor of the underlying
1552 * class. Returns {@code null} otherwise. In particular, this
1553 * method returns {@code null} if the underlying class is a local
1554 * or anonymous class immediately enclosed by a class or
1555 * interface declaration, instance initializer or static initializer.
1556 *
1557 * @return the immediately enclosing constructor of the underlying class, if
1558 * that class is a local or anonymous class; otherwise {@code null}.
1559 *
1560 * @since 1.5
1561 */
1562 public Constructor<?> getEnclosingConstructor() {
1563 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1564
1565 if (enclosingInfo == null)
1566 return null;
1567 else {
1568 if (!enclosingInfo.isConstructor())
1569 return null;
1570
1571 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1572 getFactory());
1573 Type [] parameterTypes = typeInfo.getParameterTypes();
1574 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1575
1576 // Convert Types to Classes; returned types *should*
1577 // be class objects since the methodDescriptor's used
1578 // don't have generics information
1579 for (int i = 0; i < parameterClasses.length; i++)
1580 parameterClasses[i] = toClass(parameterTypes[i]);
1581
1582
1583 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1584 Constructor<?>[] candidates = enclosingCandidate
1585 .privateGetDeclaredConstructors(false);
1586 /*
1587 * Loop over all declared constructors; match number
1588 * of and type of parameters.
1589 */
1590 ReflectionFactory fact = getReflectionFactory();
1591 for (Constructor<?> c : candidates) {
1592 if (arrayContentsEq(parameterClasses,
1593 fact.getExecutableSharedParameterTypes(c))) {
1594 return fact.copyConstructor(c);
1595 }
1596 }
1597
1598 throw new InternalError("Enclosing constructor not found");
1599 }
1600 }
1601
1602
1603 /**
1604 * If the class or interface represented by this {@code Class} object
1605 * is a member of another class, returns the {@code Class} object
1606 * representing the class in which it was declared. This method returns
1607 * null if this class or interface is not a member of any other class. If
1608 * this {@code Class} object represents an array class, a primitive
1609 * type, or void, then this method returns null.
1610 *
1611 * @return the declaring class for this class
1612 * @since 1.1
1613 */
1614 public Class<?> getDeclaringClass() {
1615 return getDeclaringClass0();
1616 }
1617
1618 private native Class<?> getDeclaringClass0();
1619
1620
1621 /**
1622 * Returns the immediately enclosing class of the underlying
1623 * class. If the underlying class is a top level class this
1624 * method returns {@code null}.
1625 * @return the immediately enclosing class of the underlying class
1626 * @since 1.5
1627 */
1628 public Class<?> getEnclosingClass() {
1629 // There are five kinds of classes (or interfaces):
1630 // a) Top level classes
1631 // b) Nested classes (static member classes)
1632 // c) Inner classes (non-static member classes)
1633 // d) Local classes (named classes declared within a method)
1634 // e) Anonymous classes
1635
1636
1637 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1638 // attribute if and only if it is a local class or an
1639 // anonymous class.
1640 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1641 Class<?> enclosingCandidate;
1642
1643 if (enclosingInfo == null) {
1644 // This is a top level or a nested class or an inner class (a, b, or c)
1645 enclosingCandidate = getDeclaringClass0();
1646 } else {
1647 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1648 // This is a local class or an anonymous class (d or e)
1649 if (enclosingClass == this || enclosingClass == null)
1650 throw new InternalError("Malformed enclosing method information");
1651 else
1652 enclosingCandidate = enclosingClass;
1653 }
1654 return enclosingCandidate;
1655 }
1656
1657 /**
1658 * Returns the simple name of the underlying class as given in the
1659 * source code. An empty string is returned if the underlying class is
1660 * {@linkplain #isAnonymousClass() anonymous}.
1661 * A {@linkplain #isSynthetic() synthetic class}, one not present
1662 * in source code, can have a non-empty name including special
1663 * characters, such as "{@code $}".
1664 *
1665 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1666 * component type with "[]" appended. In particular the simple
1667 * name of an array class whose component type is anonymous is "[]".
1668 *
1669 * @return the simple name of the underlying class
1670 * @since 1.5
1671 */
1672 public String getSimpleName() {
1673 ReflectionData<T> rd = reflectionData();
1674 String simpleName = rd.simpleName;
1675 if (simpleName == null) {
1676 rd.simpleName = simpleName = getSimpleName0();
1677 }
1678 return simpleName;
1679 }
1680
1681 private String getSimpleName0() {
1682 if (isArray()) {
1683 return getComponentType().getSimpleName().concat("[]");
1684 }
1685 String simpleName = getSimpleBinaryName();
1686 if (simpleName == null) { // top level class
1687 simpleName = getName();
1688 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1689 }
1690 return simpleName;
1691 }
1692
1693 /**
1694 * Return an informative string for the name of this class or interface.
1695 *
1696 * @return an informative string for the name of this class or interface
1697 * @since 1.8
1698 */
1699 public String getTypeName() {
1700 if (isArray()) {
1701 try {
1702 Class<?> cl = this;
1703 int dimensions = 0;
1704 do {
1705 dimensions++;
1706 cl = cl.getComponentType();
1707 } while (cl.isArray());
1708 return cl.getName().concat("[]".repeat(dimensions));
1709 } catch (Throwable e) { /*FALLTHRU*/ }
1710 }
1711 return getName();
1712 }
1713
1714 /**
1715 * Returns the canonical name of the underlying class as
1716 * defined by <cite>The Java Language Specification</cite>.
1717 * Returns {@code null} if the underlying class does not have a canonical
1718 * name. Classes without canonical names include:
1719 * <ul>
1720 * <li>a {@linkplain #isLocalClass() local class}
1721 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1722 * <li>a {@linkplain #isHidden() hidden class}
1723 * <li>an array whose component type does not have a canonical name</li>
1724 * </ul>
1725 *
1726 * The canonical name for a primitive class is the keyword for the
1727 * corresponding primitive type ({@code byte}, {@code short},
1728 * {@code char}, {@code int}, and so on).
1729 *
1730 * <p>An array type has a canonical name if and only if its
1731 * component type has a canonical name. When an array type has a
1732 * canonical name, it is equal to the canonical name of the
1733 * component type followed by "{@code []}".
1734 *
1735 * @return the canonical name of the underlying class if it exists, and
1736 * {@code null} otherwise.
1737 * @jls 6.7 Fully Qualified Names and Canonical Names
1738 * @since 1.5
1739 */
1740 public String getCanonicalName() {
1741 ReflectionData<T> rd = reflectionData();
1742 String canonicalName = rd.canonicalName;
1743 if (canonicalName == null) {
1744 rd.canonicalName = canonicalName = getCanonicalName0();
1745 }
1746 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1747 }
1748
1749 private String getCanonicalName0() {
1750 if (isArray()) {
1751 String canonicalName = getComponentType().getCanonicalName();
1752 if (canonicalName != null)
1753 return canonicalName.concat("[]");
1754 else
1755 return ReflectionData.NULL_SENTINEL;
1756 }
1757 if (isHidden() || isLocalOrAnonymousClass())
1758 return ReflectionData.NULL_SENTINEL;
1759 Class<?> enclosingClass = getEnclosingClass();
1760 if (enclosingClass == null) { // top level class
1761 return getName();
1762 } else {
1763 String enclosingName = enclosingClass.getCanonicalName();
1764 if (enclosingName == null)
1765 return ReflectionData.NULL_SENTINEL;
1766 String simpleName = getSimpleName();
1767 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1768 .append(enclosingName)
1769 .append('.')
1770 .append(simpleName)
1771 .toString();
1772 }
1773 }
1774
1775 /**
1776 * Returns {@code true} if and only if the underlying class
1777 * is an anonymous class.
1778 *
1779 * @apiNote
1780 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1781 *
1782 * @return {@code true} if and only if this class is an anonymous class.
1783 * @since 1.5
1784 * @jls 15.9.5 Anonymous Class Declarations
1785 */
1786 public boolean isAnonymousClass() {
1787 return !isArray() && isLocalOrAnonymousClass() &&
1788 getSimpleBinaryName0() == null;
1789 }
1790
1791 /**
1792 * Returns {@code true} if and only if the underlying class
1793 * is a local class.
1794 *
1795 * @return {@code true} if and only if this class is a local class.
1796 * @since 1.5
1797 * @jls 14.3 Local Class and Interface Declarations
1798 */
1799 public boolean isLocalClass() {
1800 return isLocalOrAnonymousClass() &&
1801 (isArray() || getSimpleBinaryName0() != null);
1802 }
1803
1804 /**
1805 * Returns {@code true} if and only if the underlying class
1806 * is a member class.
1807 *
1808 * @return {@code true} if and only if this class is a member class.
1809 * @since 1.5
1810 * @jls 8.5 Member Class and Interface Declarations
1811 */
1812 public boolean isMemberClass() {
1813 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1814 }
1815
1816 /**
1817 * Returns the "simple binary name" of the underlying class, i.e.,
1818 * the binary name without the leading enclosing class name.
1819 * Returns {@code null} if the underlying class is a top level
1820 * class.
1821 */
1822 private String getSimpleBinaryName() {
1823 if (isTopLevelClass())
1824 return null;
1825 String name = getSimpleBinaryName0();
1826 if (name == null) // anonymous class
1827 return "";
1828 return name;
1829 }
1830
1831 private native String getSimpleBinaryName0();
1832
1833 /**
1834 * Returns {@code true} if this is a top level class. Returns {@code false}
1835 * otherwise.
1836 */
1837 private boolean isTopLevelClass() {
1838 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1839 }
1840
1841 /**
1842 * Returns {@code true} if this is a local class or an anonymous
1843 * class. Returns {@code false} otherwise.
1844 */
1845 private boolean isLocalOrAnonymousClass() {
1846 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1847 // attribute if and only if it is a local class or an
1848 // anonymous class.
1849 return hasEnclosingMethodInfo();
1850 }
1851
1852 private boolean hasEnclosingMethodInfo() {
1853 Object[] enclosingInfo = getEnclosingMethod0();
1854 if (enclosingInfo != null) {
1855 EnclosingMethodInfo.validate(enclosingInfo);
1856 return true;
1857 }
1858 return false;
1859 }
1860
1861 /**
1862 * Returns an array containing {@code Class} objects representing all
1863 * the public classes and interfaces that are members of the class
1864 * represented by this {@code Class} object. This includes public
1865 * class and interface members inherited from superclasses and public class
1866 * and interface members declared by the class. This method returns an
1867 * array of length 0 if this {@code Class} object has no public member
1868 * classes or interfaces. This method also returns an array of length 0 if
1869 * this {@code Class} object represents a primitive type, an array
1870 * class, or void.
1871 *
1872 * @return the array of {@code Class} objects representing the public
1873 * members of this class
1874 * @since 1.1
1875 */
1876 public Class<?>[] getClasses() {
1877 List<Class<?>> list = new ArrayList<>();
1878 Class<?> currentClass = Class.this;
1879 while (currentClass != null) {
1880 for (Class<?> m : currentClass.getDeclaredClasses()) {
1881 if (Modifier.isPublic(m.getModifiers())) {
1882 list.add(m);
1883 }
1884 }
1885 currentClass = currentClass.getSuperclass();
1886 }
1887 return list.toArray(new Class<?>[0]);
1888 }
1889
1890
1891 /**
1892 * Returns an array containing {@code Field} objects reflecting all
1893 * the accessible public fields of the class or interface represented by
1894 * this {@code Class} object.
1895 *
1896 * <p> If this {@code Class} object represents a class or interface with
1897 * no accessible public fields, then this method returns an array of length
1898 * 0.
1899 *
1900 * <p> If this {@code Class} object represents a class, then this method
1901 * returns the public fields of the class and of all its superclasses and
1902 * superinterfaces.
1903 *
1904 * <p> If this {@code Class} object represents an interface, then this
1905 * method returns the fields of the interface and of all its
1906 * superinterfaces.
1907 *
1908 * <p> If this {@code Class} object represents an array type, a primitive
1909 * type, or void, then this method returns an array of length 0.
1910 *
1911 * <p> The elements in the returned array are not sorted and are not in any
1912 * particular order.
1913 *
1914 * @return the array of {@code Field} objects representing the
1915 * public fields
1916 *
1917 * @since 1.1
1918 * @jls 8.2 Class Members
1919 * @jls 8.3 Field Declarations
1920 */
1921 public Field[] getFields() {
1922 return copyFields(privateGetPublicFields());
1923 }
1924
1925
1926 /**
1927 * Returns an array containing {@code Method} objects reflecting all the
1928 * public methods of the class or interface represented by this {@code
1929 * Class} object, including those declared by the class or interface and
1930 * those inherited from superclasses and superinterfaces.
1931 *
1932 * <p> If this {@code Class} object represents an array type, then the
1933 * returned array has a {@code Method} object for each of the public
1934 * methods inherited by the array type from {@code Object}. It does not
1935 * contain a {@code Method} object for {@code clone()}.
1936 *
1937 * <p> If this {@code Class} object represents an interface then the
1938 * returned array does not contain any implicitly declared methods from
1939 * {@code Object}. Therefore, if no methods are explicitly declared in
1940 * this interface or any of its superinterfaces then the returned array
1941 * has length 0. (Note that a {@code Class} object which represents a class
1942 * always has public methods, inherited from {@code Object}.)
1943 *
1944 * <p> The returned array never contains methods with names {@value
1945 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1946 *
1947 * <p> The elements in the returned array are not sorted and are not in any
1948 * particular order.
1949 *
1950 * <p> Generally, the result is computed as with the following 4 step algorithm.
1951 * Let C be the class or interface represented by this {@code Class} object:
1952 * <ol>
1953 * <li> A union of methods is composed of:
1954 * <ol type="a">
1955 * <li> C's declared public instance and static methods as returned by
1956 * {@link #getDeclaredMethods()} and filtered to include only public
1957 * methods.</li>
1958 * <li> If C is a class other than {@code Object}, then include the result
1959 * of invoking this algorithm recursively on the superclass of C.</li>
1960 * <li> Include the results of invoking this algorithm recursively on all
1961 * direct superinterfaces of C, but include only instance methods.</li>
1962 * </ol></li>
1963 * <li> Union from step 1 is partitioned into subsets of methods with same
1964 * signature (name, parameter types) and return type.</li>
1965 * <li> Within each such subset only the most specific methods are selected.
1966 * Let method M be a method from a set of methods with same signature
1967 * and return type. M is most specific if there is no such method
1968 * N != M from the same set, such that N is more specific than M.
1969 * N is more specific than M if:
1970 * <ol type="a">
1971 * <li> N is declared by a class and M is declared by an interface; or</li>
1972 * <li> N and M are both declared by classes or both by interfaces and
1973 * N's declaring type is the same as or a subtype of M's declaring type
1974 * (clearly, if M's and N's declaring types are the same type, then
1975 * M and N are the same method).</li>
1976 * </ol></li>
1977 * <li> The result of this algorithm is the union of all selected methods from
1978 * step 3.</li>
1979 * </ol>
1980 *
1981 * @apiNote There may be more than one method with a particular name
1982 * and parameter types in a class because while the Java language forbids a
1983 * class to declare multiple methods with the same signature but different
1984 * return types, the Java virtual machine does not. This
1985 * increased flexibility in the virtual machine can be used to
1986 * implement various language features. For example, covariant
1987 * returns can be implemented with {@linkplain
1988 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
1989 * method and the overriding method would have the same
1990 * signature but different return types.
1991 *
1992 * @return the array of {@code Method} objects representing the
1993 * public methods of this class
1994 *
1995 * @jls 8.2 Class Members
1996 * @jls 8.4 Method Declarations
1997 * @since 1.1
1998 */
1999 public Method[] getMethods() {
2000 return copyMethods(privateGetPublicMethods());
2001 }
2002
2003
2004 /**
2005 * Returns an array containing {@code Constructor} objects reflecting
2006 * all the public constructors of the class represented by this
2007 * {@code Class} object. An array of length 0 is returned if the
2008 * class has no public constructors, or if the class is an array class, or
2009 * if the class reflects a primitive type or void.
2010 *
2011 * @apiNote
2012 * While this method returns an array of {@code
2013 * Constructor<T>} objects (that is an array of constructors from
2014 * this class), the return type of this method is {@code
2015 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2016 * might be expected. This less informative return type is
2017 * necessary since after being returned from this method, the
2018 * array could be modified to hold {@code Constructor} objects for
2019 * different classes, which would violate the type guarantees of
2020 * {@code Constructor<T>[]}.
2021 *
2022 * @return the array of {@code Constructor} objects representing the
2023 * public constructors of this class
2024 *
2025 * @see #getDeclaredConstructors()
2026 * @since 1.1
2027 */
2028 public Constructor<?>[] getConstructors() {
2029 return copyConstructors(privateGetDeclaredConstructors(true));
2030 }
2031
2032
2033 /**
2034 * Returns a {@code Field} object that reflects the specified public member
2035 * field of the class or interface represented by this {@code Class}
2036 * object. The {@code name} parameter is a {@code String} specifying the
2037 * simple name of the desired field.
2038 *
2039 * <p> The field to be reflected is determined by the algorithm that
2040 * follows. Let C be the class or interface represented by this {@code Class} object:
2041 *
2042 * <OL>
2043 * <LI> If C declares a public field with the name specified, that is the
2044 * field to be reflected.</LI>
2045 * <LI> If no field was found in step 1 above, this algorithm is applied
2046 * recursively to each direct superinterface of C. The direct
2047 * superinterfaces are searched in the order they were declared.</LI>
2048 * <LI> If no field was found in steps 1 and 2 above, and C has a
2049 * superclass S, then this algorithm is invoked recursively upon S.
2050 * If C has no superclass, then a {@code NoSuchFieldException}
2051 * is thrown.</LI>
2052 * </OL>
2053 *
2054 * <p> If this {@code Class} object represents an array type, then this
2055 * method does not find the {@code length} field of the array type.
2056 *
2057 * @param name the field name
2058 * @return the {@code Field} object of this class specified by
2059 * {@code name}
2060 * @throws NoSuchFieldException if a field with the specified name is
2061 * not found.
2062 * @throws NullPointerException if {@code name} is {@code null}
2063 *
2064 * @since 1.1
2065 * @jls 8.2 Class Members
2066 * @jls 8.3 Field Declarations
2067 */
2068 public Field getField(String name) throws NoSuchFieldException {
2069 Objects.requireNonNull(name);
2070 Field field = getField0(name);
2071 if (field == null) {
2072 throw new NoSuchFieldException(name);
2073 }
2074 return getReflectionFactory().copyField(field);
2075 }
2076
2077
2078 /**
2079 * Returns a {@code Method} object that reflects the specified public
2080 * member method of the class or interface represented by this
2081 * {@code Class} object. The {@code name} parameter is a
2082 * {@code String} specifying the simple name of the desired method. The
2083 * {@code parameterTypes} parameter is an array of {@code Class}
2084 * objects that identify the method's formal parameter types, in declared
2085 * order. If {@code parameterTypes} is {@code null}, it is
2086 * treated as if it were an empty array.
2087 *
2088 * <p> If this {@code Class} object represents an array type, then this
2089 * method finds any public method inherited by the array type from
2090 * {@code Object} except method {@code clone()}.
2091 *
2092 * <p> If this {@code Class} object represents an interface then this
2093 * method does not find any implicitly declared method from
2094 * {@code Object}. Therefore, if no methods are explicitly declared in
2095 * this interface or any of its superinterfaces, then this method does not
2096 * find any method.
2097 *
2098 * <p> This method does not find any method with name {@value
2099 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2100 *
2101 * <p> Generally, the method to be reflected is determined by the 4 step
2102 * algorithm that follows.
2103 * Let C be the class or interface represented by this {@code Class} object:
2104 * <ol>
2105 * <li> A union of methods is composed of:
2106 * <ol type="a">
2107 * <li> C's declared public instance and static methods as returned by
2108 * {@link #getDeclaredMethods()} and filtered to include only public
2109 * methods that match given {@code name} and {@code parameterTypes}</li>
2110 * <li> If C is a class other than {@code Object}, then include the result
2111 * of invoking this algorithm recursively on the superclass of C.</li>
2112 * <li> Include the results of invoking this algorithm recursively on all
2113 * direct superinterfaces of C, but include only instance methods.</li>
2114 * </ol></li>
2115 * <li> This union is partitioned into subsets of methods with same
2116 * return type (the selection of methods from step 1 also guarantees that
2117 * they have the same method name and parameter types).</li>
2118 * <li> Within each such subset only the most specific methods are selected.
2119 * Let method M be a method from a set of methods with same VM
2120 * signature (return type, name, parameter types).
2121 * M is most specific if there is no such method N != M from the same
2122 * set, such that N is more specific than M. N is more specific than M
2123 * if:
2124 * <ol type="a">
2125 * <li> N is declared by a class and M is declared by an interface; or</li>
2126 * <li> N and M are both declared by classes or both by interfaces and
2127 * N's declaring type is the same as or a subtype of M's declaring type
2128 * (clearly, if M's and N's declaring types are the same type, then
2129 * M and N are the same method).</li>
2130 * </ol></li>
2131 * <li> The result of this algorithm is chosen arbitrarily from the methods
2132 * with most specific return type among all selected methods from step 3.
2133 * Let R be a return type of a method M from the set of all selected methods
2134 * from step 3. M is a method with most specific return type if there is
2135 * no such method N != M from the same set, having return type S != R,
2136 * such that S is a subtype of R as determined by
2137 * R.class.{@link #isAssignableFrom}(S.class).
2138 * </ol>
2139 *
2140 * @apiNote There may be more than one method with matching name and
2141 * parameter types in a class because while the Java language forbids a
2142 * class to declare multiple methods with the same signature but different
2143 * return types, the Java virtual machine does not. This
2144 * increased flexibility in the virtual machine can be used to
2145 * implement various language features. For example, covariant
2146 * returns can be implemented with {@linkplain
2147 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2148 * method and the overriding method would have the same
2149 * signature but different return types. This method would return the
2150 * overriding method as it would have a more specific return type.
2151 *
2152 * @param name the name of the method
2153 * @param parameterTypes the list of parameters
2154 * @return the {@code Method} object that matches the specified
2155 * {@code name} and {@code parameterTypes}
2156 * @throws NoSuchMethodException if a matching method is not found
2157 * or if the name is {@value ConstantDescs#INIT_NAME} or
2158 * {@value ConstantDescs#CLASS_INIT_NAME}.
2159 * @throws NullPointerException if {@code name} is {@code null}
2160 *
2161 * @jls 8.2 Class Members
2162 * @jls 8.4 Method Declarations
2163 * @since 1.1
2164 */
2165 public Method getMethod(String name, Class<?>... parameterTypes)
2166 throws NoSuchMethodException {
2167 Objects.requireNonNull(name);
2168 Method method = getMethod0(name, parameterTypes);
2169 if (method == null) {
2170 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2171 }
2172 return getReflectionFactory().copyMethod(method);
2173 }
2174
2175 /**
2176 * Returns a {@code Constructor} object that reflects the specified
2177 * public constructor of the class represented by this {@code Class}
2178 * object. The {@code parameterTypes} parameter is an array of
2179 * {@code Class} objects that identify the constructor's formal
2180 * parameter types, in declared order.
2181 *
2182 * If this {@code Class} object represents an inner class
2183 * declared in a non-static context, the formal parameter types
2184 * include the explicit enclosing instance as the first parameter.
2185 *
2186 * <p> The constructor to reflect is the public constructor of the class
2187 * represented by this {@code Class} object whose formal parameter
2188 * types match those specified by {@code parameterTypes}.
2189 *
2190 * @param parameterTypes the parameter array
2191 * @return the {@code Constructor} object of the public constructor that
2192 * matches the specified {@code parameterTypes}
2193 * @throws NoSuchMethodException if a matching constructor is not found,
2194 * including when this {@code Class} object represents
2195 * an interface, a primitive type, an array class, or void.
2196 *
2197 * @see #getDeclaredConstructor(Class[])
2198 * @since 1.1
2199 */
2200 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2201 throws NoSuchMethodException {
2202 return getReflectionFactory().copyConstructor(
2203 getConstructor0(parameterTypes, Member.PUBLIC));
2204 }
2205
2206
2207 /**
2208 * Returns an array of {@code Class} objects reflecting all the
2209 * classes and interfaces declared as members of the class represented by
2210 * this {@code Class} object. This includes public, protected, default
2211 * (package) access, and private classes and interfaces declared by the
2212 * class, but excludes inherited classes and interfaces. This method
2213 * returns an array of length 0 if the class declares no classes or
2214 * interfaces as members, or if this {@code Class} object represents a
2215 * primitive type, an array class, or void.
2216 *
2217 * @return the array of {@code Class} objects representing all the
2218 * declared members of this class
2219 *
2220 * @since 1.1
2221 * @jls 8.5 Member Class and Interface Declarations
2222 */
2223 public Class<?>[] getDeclaredClasses() {
2224 return getDeclaredClasses0();
2225 }
2226
2227
2228 /**
2229 * Returns an array of {@code Field} objects reflecting all the fields
2230 * declared by the class or interface represented by this
2231 * {@code Class} object. This includes public, protected, default
2232 * (package) access, and private fields, but excludes inherited fields.
2233 *
2234 * <p> If this {@code Class} object represents a class or interface with no
2235 * declared fields, then this method returns an array of length 0.
2236 *
2237 * <p> If this {@code Class} object represents an array type, a primitive
2238 * type, or void, then this method returns an array of length 0.
2239 *
2240 * <p> The elements in the returned array are not sorted and are not in any
2241 * particular order.
2242 *
2243 * @return the array of {@code Field} objects representing all the
2244 * declared fields of this class
2245 *
2246 * @since 1.1
2247 * @jls 8.2 Class Members
2248 * @jls 8.3 Field Declarations
2249 */
2250 public Field[] getDeclaredFields() {
2251 return copyFields(privateGetDeclaredFields(false));
2252 }
2253
2254 /**
2255 * Returns an array of {@code RecordComponent} objects representing all the
2256 * record components of this record class, or {@code null} if this class is
2257 * not a record class.
2258 *
2259 * <p> The components are returned in the same order that they are declared
2260 * in the record header. The array is empty if this record class has no
2261 * components. If the class is not a record class, that is {@link
2262 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2263 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2264 * returns a non-null value.
2265 *
2266 * @apiNote
2267 * <p> The following method can be used to find the record canonical constructor:
2268 *
2269 * {@snippet lang="java" :
2270 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2271 * throws NoSuchMethodException {
2272 * Class<?>[] paramTypes =
2273 * Arrays.stream(cls.getRecordComponents())
2274 * .map(RecordComponent::getType)
2275 * .toArray(Class<?>[]::new);
2276 * return cls.getDeclaredConstructor(paramTypes);
2277 * }}
2278 *
2279 * @return An array of {@code RecordComponent} objects representing all the
2280 * record components of this record class, or {@code null} if this
2281 * class is not a record class
2282 *
2283 * @jls 8.10 Record Classes
2284 * @since 16
2285 */
2286 public RecordComponent[] getRecordComponents() {
2287 if (!isRecord()) {
2288 return null;
2289 }
2290 return getRecordComponents0();
2291 }
2292
2293 /**
2294 * Returns an array containing {@code Method} objects reflecting all the
2295 * declared methods of the class or interface represented by this {@code
2296 * Class} object, including public, protected, default (package)
2297 * access, and private methods, but excluding inherited methods.
2298 * The declared methods may include methods <em>not</em> in the
2299 * source of the class or interface, including {@linkplain
2300 * Method#isBridge bridge methods} and other {@linkplain
2301 * Executable#isSynthetic synthetic} methods added by compilers.
2302 *
2303 * <p> If this {@code Class} object represents a class or interface that
2304 * has multiple declared methods with the same name and parameter types,
2305 * but different return types, then the returned array has a {@code Method}
2306 * object for each such method.
2307 *
2308 * <p> If this {@code Class} object represents a class or interface that
2309 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2310 * then the returned array does <em>not</em> have a corresponding {@code
2311 * Method} object.
2312 *
2313 * <p> If this {@code Class} object represents a class or interface with no
2314 * declared methods, then the returned array has length 0.
2315 *
2316 * <p> If this {@code Class} object represents an array type, a primitive
2317 * type, or void, then the returned array has length 0.
2318 *
2319 * <p> The elements in the returned array are not sorted and are not in any
2320 * particular order.
2321 *
2322 * @return the array of {@code Method} objects representing all the
2323 * declared methods of this class
2324 *
2325 * @jls 8.2 Class Members
2326 * @jls 8.4 Method Declarations
2327 * @see <a
2328 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2329 * programming language and JVM modeling in core reflection</a>
2330 * @since 1.1
2331 */
2332 public Method[] getDeclaredMethods() {
2333 return copyMethods(privateGetDeclaredMethods(false));
2334 }
2335
2336 /**
2337 * Returns an array of {@code Constructor} objects reflecting all the
2338 * constructors implicitly or explicitly declared by the class represented by this
2339 * {@code Class} object. These are public, protected, default
2340 * (package) access, and private constructors. The elements in the array
2341 * returned are not sorted and are not in any particular order. If the
2342 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2343 * If a record class has a canonical constructor (JLS {@jls
2344 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2345 *
2346 * This method returns an array of length 0 if this {@code Class}
2347 * object represents an interface, a primitive type, an array class, or
2348 * void.
2349 *
2350 * @return the array of {@code Constructor} objects representing all the
2351 * declared constructors of this class
2352 *
2353 * @since 1.1
2354 * @see #getConstructors()
2355 * @jls 8.8 Constructor Declarations
2356 */
2357 public Constructor<?>[] getDeclaredConstructors() {
2358 return copyConstructors(privateGetDeclaredConstructors(false));
2359 }
2360
2361
2362 /**
2363 * Returns a {@code Field} object that reflects the specified declared
2364 * field of the class or interface represented by this {@code Class}
2365 * object. The {@code name} parameter is a {@code String} that specifies
2366 * the simple name of the desired field.
2367 *
2368 * <p> If this {@code Class} object represents an array type, then this
2369 * method does not find the {@code length} field of the array type.
2370 *
2371 * @param name the name of the field
2372 * @return the {@code Field} object for the specified field in this
2373 * class
2374 * @throws NoSuchFieldException if a field with the specified name is
2375 * not found.
2376 * @throws NullPointerException if {@code name} is {@code null}
2377 *
2378 * @since 1.1
2379 * @jls 8.2 Class Members
2380 * @jls 8.3 Field Declarations
2381 */
2382 public Field getDeclaredField(String name) throws NoSuchFieldException {
2383 Objects.requireNonNull(name);
2384 Field field = searchFields(privateGetDeclaredFields(false), name);
2385 if (field == null) {
2386 throw new NoSuchFieldException(name);
2387 }
2388 return getReflectionFactory().copyField(field);
2389 }
2390
2391
2392 /**
2393 * Returns a {@code Method} object that reflects the specified
2394 * declared method of the class or interface represented by this
2395 * {@code Class} object. The {@code name} parameter is a
2396 * {@code String} that specifies the simple name of the desired
2397 * method, and the {@code parameterTypes} parameter is an array of
2398 * {@code Class} objects that identify the method's formal parameter
2399 * types, in declared order. If more than one method with the same
2400 * parameter types is declared in a class, and one of these methods has a
2401 * return type that is more specific than any of the others, that method is
2402 * returned; otherwise one of the methods is chosen arbitrarily. If the
2403 * name is {@value ConstantDescs#INIT_NAME} or {@value
2404 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2405 * is raised.
2406 *
2407 * <p> If this {@code Class} object represents an array type, then this
2408 * method does not find the {@code clone()} method.
2409 *
2410 * @param name the name of the method
2411 * @param parameterTypes the parameter array
2412 * @return the {@code Method} object for the method of this class
2413 * matching the specified name and parameters
2414 * @throws NoSuchMethodException if a matching method is not found.
2415 * @throws NullPointerException if {@code name} is {@code null}
2416 *
2417 * @jls 8.2 Class Members
2418 * @jls 8.4 Method Declarations
2419 * @since 1.1
2420 */
2421 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2422 throws NoSuchMethodException {
2423 Objects.requireNonNull(name);
2424 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2425 if (method == null) {
2426 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2427 }
2428 return getReflectionFactory().copyMethod(method);
2429 }
2430
2431 /**
2432 * Returns the list of {@code Method} objects for the declared public
2433 * methods of this class or interface that have the specified method name
2434 * and parameter types.
2435 *
2436 * @param name the name of the method
2437 * @param parameterTypes the parameter array
2438 * @return the list of {@code Method} objects for the public methods of
2439 * this class matching the specified name and parameters
2440 */
2441 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2442 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2443 ReflectionFactory factory = getReflectionFactory();
2444 List<Method> result = new ArrayList<>();
2445 for (Method method : methods) {
2446 if (method.getName().equals(name)
2447 && Arrays.equals(
2448 factory.getExecutableSharedParameterTypes(method),
2449 parameterTypes)) {
2450 result.add(factory.copyMethod(method));
2451 }
2452 }
2453 return result;
2454 }
2455
2456 /**
2457 * Returns the most specific {@code Method} object of this class, super class or
2458 * interface that have the specified method name and parameter types.
2459 *
2460 * @param publicOnly true if only public methods are examined, otherwise all methods
2461 * @param name the name of the method
2462 * @param parameterTypes the parameter array
2463 * @return the {@code Method} object for the method found from this class matching
2464 * the specified name and parameters, or null if not found
2465 */
2466 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2467 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2468 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2469 }
2470
2471 /**
2472 * Returns a {@code Constructor} object that reflects the specified
2473 * constructor of the class represented by this
2474 * {@code Class} object. The {@code parameterTypes} parameter is
2475 * an array of {@code Class} objects that identify the constructor's
2476 * formal parameter types, in declared order.
2477 *
2478 * If this {@code Class} object represents an inner class
2479 * declared in a non-static context, the formal parameter types
2480 * include the explicit enclosing instance as the first parameter.
2481 *
2482 * @param parameterTypes the parameter array
2483 * @return The {@code Constructor} object for the constructor with the
2484 * specified parameter list
2485 * @throws NoSuchMethodException if a matching constructor is not found,
2486 * including when this {@code Class} object represents
2487 * an interface, a primitive type, an array class, or void.
2488 *
2489 * @see #getConstructor(Class[])
2490 * @since 1.1
2491 */
2492 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2493 throws NoSuchMethodException {
2494 return getReflectionFactory().copyConstructor(
2495 getConstructor0(parameterTypes, Member.DECLARED));
2496 }
2497
2498 /**
2499 * Finds a resource with a given name.
2500 *
2501 * <p> If this class is in a named {@link Module Module} then this method
2502 * will attempt to find the resource in the module. This is done by
2503 * delegating to the module's class loader {@link
2504 * ClassLoader#findResource(String,String) findResource(String,String)}
2505 * method, invoking it with the module name and the absolute name of the
2506 * resource. Resources in named modules are subject to the rules for
2507 * encapsulation specified in the {@code Module} {@link
2508 * Module#getResourceAsStream getResourceAsStream} method and so this
2509 * method returns {@code null} when the resource is a
2510 * non-"{@code .class}" resource in a package that is not open to the
2511 * caller's module.
2512 *
2513 * <p> Otherwise, if this class is not in a named module then the rules for
2514 * searching resources associated with a given class are implemented by the
2515 * defining {@linkplain ClassLoader class loader} of the class. This method
2516 * delegates to this {@code Class} object's class loader.
2517 * If this {@code Class} object was loaded by the bootstrap class loader,
2518 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2519 *
2520 * <p> Before delegation, an absolute resource name is constructed from the
2521 * given resource name using this algorithm:
2522 *
2523 * <ul>
2524 *
2525 * <li> If the {@code name} begins with a {@code '/'}
2526 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2527 * portion of the {@code name} following the {@code '/'}.
2528 *
2529 * <li> Otherwise, the absolute name is of the following form:
2530 *
2531 * <blockquote>
2532 * {@code modified_package_name/name}
2533 * </blockquote>
2534 *
2535 * <p> Where the {@code modified_package_name} is the package name of this
2536 * object with {@code '/'} substituted for {@code '.'}
2537 * (<code>'\u002e'</code>).
2538 *
2539 * </ul>
2540 *
2541 * @param name name of the desired resource
2542 * @return A {@link java.io.InputStream} object; {@code null} if no
2543 * resource with this name is found, or the resource is in a package
2544 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2545 * least the caller module.
2546 * @throws NullPointerException If {@code name} is {@code null}
2547 *
2548 * @see Module#getResourceAsStream(String)
2549 * @since 1.1
2550 */
2551 @CallerSensitive
2552 public InputStream getResourceAsStream(String name) {
2553 name = resolveName(name);
2554
2555 Module thisModule = getModule();
2556 if (thisModule.isNamed()) {
2557 // check if resource can be located by caller
2558 if (Resources.canEncapsulate(name)
2559 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2560 return null;
2561 }
2562
2563 // resource not encapsulated or in package open to caller
2564 String mn = thisModule.getName();
2565 ClassLoader cl = classLoader;
2566 try {
2567
2568 // special-case built-in class loaders to avoid the
2569 // need for a URL connection
2570 if (cl == null) {
2571 return BootLoader.findResourceAsStream(mn, name);
2572 } else if (cl instanceof BuiltinClassLoader bcl) {
2573 return bcl.findResourceAsStream(mn, name);
2574 } else {
2575 URL url = cl.findResource(mn, name);
2576 return (url != null) ? url.openStream() : null;
2577 }
2578
2579 } catch (IOException | SecurityException e) {
2580 return null;
2581 }
2582 }
2583
2584 // unnamed module
2585 ClassLoader cl = classLoader;
2586 if (cl == null) {
2587 return ClassLoader.getSystemResourceAsStream(name);
2588 } else {
2589 return cl.getResourceAsStream(name);
2590 }
2591 }
2592
2593 /**
2594 * Finds a resource with a given name.
2595 *
2596 * <p> If this class is in a named {@link Module Module} then this method
2597 * will attempt to find the resource in the module. This is done by
2598 * delegating to the module's class loader {@link
2599 * ClassLoader#findResource(String,String) findResource(String,String)}
2600 * method, invoking it with the module name and the absolute name of the
2601 * resource. Resources in named modules are subject to the rules for
2602 * encapsulation specified in the {@code Module} {@link
2603 * Module#getResourceAsStream getResourceAsStream} method and so this
2604 * method returns {@code null} when the resource is a
2605 * non-"{@code .class}" resource in a package that is not open to the
2606 * caller's module.
2607 *
2608 * <p> Otherwise, if this class is not in a named module then the rules for
2609 * searching resources associated with a given class are implemented by the
2610 * defining {@linkplain ClassLoader class loader} of the class. This method
2611 * delegates to this {@code Class} object's class loader.
2612 * If this {@code Class} object was loaded by the bootstrap class loader,
2613 * the method delegates to {@link ClassLoader#getSystemResource}.
2614 *
2615 * <p> Before delegation, an absolute resource name is constructed from the
2616 * given resource name using this algorithm:
2617 *
2618 * <ul>
2619 *
2620 * <li> If the {@code name} begins with a {@code '/'}
2621 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2622 * portion of the {@code name} following the {@code '/'}.
2623 *
2624 * <li> Otherwise, the absolute name is of the following form:
2625 *
2626 * <blockquote>
2627 * {@code modified_package_name/name}
2628 * </blockquote>
2629 *
2630 * <p> Where the {@code modified_package_name} is the package name of this
2631 * object with {@code '/'} substituted for {@code '.'}
2632 * (<code>'\u002e'</code>).
2633 *
2634 * </ul>
2635 *
2636 * @param name name of the desired resource
2637 * @return A {@link java.net.URL} object; {@code null} if no resource with
2638 * this name is found, the resource cannot be located by a URL, or the
2639 * resource is in a package that is not
2640 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2641 * module.
2642 * @throws NullPointerException If {@code name} is {@code null}
2643 * @since 1.1
2644 */
2645 @CallerSensitive
2646 public URL getResource(String name) {
2647 name = resolveName(name);
2648
2649 Module thisModule = getModule();
2650 if (thisModule.isNamed()) {
2651 // check if resource can be located by caller
2652 if (Resources.canEncapsulate(name)
2653 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2654 return null;
2655 }
2656
2657 // resource not encapsulated or in package open to caller
2658 String mn = thisModule.getName();
2659 ClassLoader cl = classLoader;
2660 try {
2661 if (cl == null) {
2662 return BootLoader.findResource(mn, name);
2663 } else {
2664 return cl.findResource(mn, name);
2665 }
2666 } catch (IOException ioe) {
2667 return null;
2668 }
2669 }
2670
2671 // unnamed module
2672 ClassLoader cl = classLoader;
2673 if (cl == null) {
2674 return ClassLoader.getSystemResource(name);
2675 } else {
2676 return cl.getResource(name);
2677 }
2678 }
2679
2680 /**
2681 * Returns true if a resource with the given name can be located by the
2682 * given caller. All resources in a module can be located by code in
2683 * the module. For other callers, then the package needs to be open to
2684 * the caller.
2685 */
2686 private boolean isOpenToCaller(String name, Class<?> caller) {
2687 // assert getModule().isNamed();
2688 Module thisModule = getModule();
2689 Module callerModule = (caller != null) ? caller.getModule() : null;
2690 if (callerModule != thisModule) {
2691 String pn = Resources.toPackageName(name);
2692 if (thisModule.getDescriptor().packages().contains(pn)) {
2693 if (callerModule == null) {
2694 // no caller, return true if the package is open to all modules
2695 return thisModule.isOpen(pn);
2696 }
2697 if (!thisModule.isOpen(pn, callerModule)) {
2698 // package not open to caller
2699 return false;
2700 }
2701 }
2702 }
2703 return true;
2704 }
2705
2706 /**
2707 * Returns the {@code ProtectionDomain} of this class.
2708 *
2709 * @return the ProtectionDomain of this class
2710 *
2711 * @see java.security.ProtectionDomain
2712 * @since 1.2
2713 */
2714 public ProtectionDomain getProtectionDomain() {
2715 return protectionDomain();
2716 }
2717
2718 /** Holder for the protection domain returned when the internal domain is null */
2719 private static class Holder {
2720 private static final ProtectionDomain allPermDomain;
2721 static {
2722 Permissions perms = new Permissions();
2723 perms.add(SecurityConstants.ALL_PERMISSION);
2724 allPermDomain = new ProtectionDomain(null, perms);
2725 }
2726 }
2727
2728 // package-private
2729 ProtectionDomain protectionDomain() {
2730 ProtectionDomain pd = getProtectionDomain0();
2731 if (pd == null) {
2732 return Holder.allPermDomain;
2733 } else {
2734 return pd;
2735 }
2736 }
2737
2738 /**
2739 * Returns the ProtectionDomain of this class.
2740 */
2741 private native ProtectionDomain getProtectionDomain0();
2742
2743 /*
2744 * Returns the Class object for the named primitive type. Type parameter T
2745 * avoids redundant casts for trusted code.
2746 */
2747 static native <T> Class<T> getPrimitiveClass(String name);
2748
2749 /**
2750 * Add a package name prefix if the name is not absolute. Remove leading "/"
2751 * if name is absolute
2752 */
2753 private String resolveName(String name) {
2754 if (!name.startsWith("/")) {
2755 String baseName = getPackageName();
2756 if (!baseName.isEmpty()) {
2757 int len = baseName.length() + 1 + name.length();
2758 StringBuilder sb = new StringBuilder(len);
2759 name = sb.append(baseName.replace('.', '/'))
2760 .append('/')
2761 .append(name)
2762 .toString();
2763 }
2764 } else {
2765 name = name.substring(1);
2766 }
2767 return name;
2768 }
2769
2770 /**
2771 * Atomic operations support.
2772 */
2773 private static class Atomic {
2774 // initialize Unsafe machinery here, since we need to call Class.class instance method
2775 // and have to avoid calling it in the static initializer of the Class class...
2776 private static final Unsafe unsafe = Unsafe.getUnsafe();
2777 // offset of Class.reflectionData instance field
2778 private static final long reflectionDataOffset
2779 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2780 // offset of Class.annotationType instance field
2781 private static final long annotationTypeOffset
2782 = unsafe.objectFieldOffset(Class.class, "annotationType");
2783 // offset of Class.annotationData instance field
2784 private static final long annotationDataOffset
2785 = unsafe.objectFieldOffset(Class.class, "annotationData");
2786
2787 static <T> boolean casReflectionData(Class<?> clazz,
2788 SoftReference<ReflectionData<T>> oldData,
2789 SoftReference<ReflectionData<T>> newData) {
2790 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2791 }
2792
2793 static boolean casAnnotationType(Class<?> clazz,
2794 AnnotationType oldType,
2795 AnnotationType newType) {
2796 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2797 }
2798
2799 static boolean casAnnotationData(Class<?> clazz,
2800 AnnotationData oldData,
2801 AnnotationData newData) {
2802 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2803 }
2804 }
2805
2806 /**
2807 * Reflection support.
2808 */
2809
2810 // Reflection data caches various derived names and reflective members. Cached
2811 // values may be invalidated when JVM TI RedefineClasses() is called
2812 private static class ReflectionData<T> {
2813 volatile Field[] declaredFields;
2814 volatile Field[] publicFields;
2815 volatile Method[] declaredMethods;
2816 volatile Method[] publicMethods;
2817 volatile Constructor<T>[] declaredConstructors;
2818 volatile Constructor<T>[] publicConstructors;
2819 // Intermediate results for getFields and getMethods
2820 volatile Field[] declaredPublicFields;
2821 volatile Method[] declaredPublicMethods;
2822 volatile Class<?>[] interfaces;
2823
2824 // Cached names
2825 String simpleName;
2826 String canonicalName;
2827 static final String NULL_SENTINEL = new String();
2828
2829 // Value of classRedefinedCount when we created this ReflectionData instance
2830 final int redefinedCount;
2831
2832 ReflectionData(int redefinedCount) {
2833 this.redefinedCount = redefinedCount;
2834 }
2835 }
2836
2837 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2838
2839 // Incremented by the VM on each call to JVM TI RedefineClasses()
2840 // that redefines this class or a superclass.
2841 private transient volatile int classRedefinedCount;
2842
2843 // Lazily create and cache ReflectionData
2844 private ReflectionData<T> reflectionData() {
2845 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2846 int classRedefinedCount = this.classRedefinedCount;
2847 ReflectionData<T> rd;
2848 if (reflectionData != null &&
2849 (rd = reflectionData.get()) != null &&
2850 rd.redefinedCount == classRedefinedCount) {
2851 return rd;
2852 }
2853 // else no SoftReference or cleared SoftReference or stale ReflectionData
2854 // -> create and replace new instance
2855 return newReflectionData(reflectionData, classRedefinedCount);
2856 }
2857
2858 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2859 int classRedefinedCount) {
2860 while (true) {
2861 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2862 // try to CAS it...
2863 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
2864 return rd;
2865 }
2866 // else retry
2867 oldReflectionData = this.reflectionData;
2868 classRedefinedCount = this.classRedefinedCount;
2869 if (oldReflectionData != null &&
2870 (rd = oldReflectionData.get()) != null &&
2871 rd.redefinedCount == classRedefinedCount) {
2872 return rd;
2873 }
2874 }
2875 }
2876
2877 // Generic signature handling
2878 private native String getGenericSignature0();
2879
2880 // Generic info repository; lazily initialized
2881 private transient volatile ClassRepository genericInfo;
2882
2883 // accessor for factory
2884 private GenericsFactory getFactory() {
2885 // create scope and factory
2886 return CoreReflectionFactory.make(this, ClassScope.make(this));
2887 }
2888
2889 // accessor for generic info repository;
2890 // generic info is lazily initialized
2891 private ClassRepository getGenericInfo() {
2892 ClassRepository genericInfo = this.genericInfo;
2893 if (genericInfo == null) {
2894 String signature = getGenericSignature0();
2895 if (signature == null) {
2896 genericInfo = ClassRepository.NONE;
2897 } else {
2898 genericInfo = ClassRepository.make(signature, getFactory());
2899 }
2900 this.genericInfo = genericInfo;
2901 }
2902 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2903 }
2904
2905 // Annotations handling
2906 native byte[] getRawAnnotations();
2907 // Since 1.8
2908 native byte[] getRawTypeAnnotations();
2909 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2910 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2911 }
2912
2913 native ConstantPool getConstantPool();
2914
2915 //
2916 //
2917 // java.lang.reflect.Field handling
2918 //
2919 //
2920
2921 // Returns an array of "root" fields. These Field objects must NOT
2922 // be propagated to the outside world, but must instead be copied
2923 // via ReflectionFactory.copyField.
2924 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2925 Field[] res;
2926 ReflectionData<T> rd = reflectionData();
2927 if (rd != null) {
2928 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2929 if (res != null) return res;
2930 }
2931 // No cached value available; request value from VM
2932 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2933 if (rd != null) {
2934 if (publicOnly) {
2935 rd.declaredPublicFields = res;
2936 } else {
2937 rd.declaredFields = res;
2938 }
2939 }
2940 return res;
2941 }
2942
2943 // Returns an array of "root" fields. These Field objects must NOT
2944 // be propagated to the outside world, but must instead be copied
2945 // via ReflectionFactory.copyField.
2946 private Field[] privateGetPublicFields() {
2947 Field[] res;
2948 ReflectionData<T> rd = reflectionData();
2949 if (rd != null) {
2950 res = rd.publicFields;
2951 if (res != null) return res;
2952 }
2953
2954 // Use a linked hash set to ensure order is preserved and
2955 // fields from common super interfaces are not duplicated
2956 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2957
2958 // Local fields
2959 addAll(fields, privateGetDeclaredFields(true));
2960
2961 // Direct superinterfaces, recursively
2962 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2963 addAll(fields, si.privateGetPublicFields());
2964 }
2965
2966 // Direct superclass, recursively
2967 Class<?> sc = getSuperclass();
2968 if (sc != null) {
2969 addAll(fields, sc.privateGetPublicFields());
2970 }
2971
2972 res = fields.toArray(new Field[0]);
2973 if (rd != null) {
2974 rd.publicFields = res;
2975 }
2976 return res;
2977 }
2978
2979 private static void addAll(Collection<Field> c, Field[] o) {
2980 for (Field f : o) {
2981 c.add(f);
2982 }
2983 }
2984
2985
2986 //
2987 //
2988 // java.lang.reflect.Constructor handling
2989 //
2990 //
2991
2992 // Returns an array of "root" constructors. These Constructor
2993 // objects must NOT be propagated to the outside world, but must
2994 // instead be copied via ReflectionFactory.copyConstructor.
2995 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
2996 Constructor<T>[] res;
2997 ReflectionData<T> rd = reflectionData();
2998 if (rd != null) {
2999 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3000 if (res != null) return res;
3001 }
3002 // No cached value available; request value from VM
3003 if (isInterface()) {
3004 @SuppressWarnings("unchecked")
3005 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3006 res = temporaryRes;
3007 } else {
3008 res = getDeclaredConstructors0(publicOnly);
3009 }
3010 if (rd != null) {
3011 if (publicOnly) {
3012 rd.publicConstructors = res;
3013 } else {
3014 rd.declaredConstructors = res;
3015 }
3016 }
3017 return res;
3018 }
3019
3020 //
3021 //
3022 // java.lang.reflect.Method handling
3023 //
3024 //
3025
3026 // Returns an array of "root" methods. These Method objects must NOT
3027 // be propagated to the outside world, but must instead be copied
3028 // via ReflectionFactory.copyMethod.
3029 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3030 Method[] res;
3031 ReflectionData<T> rd = reflectionData();
3032 if (rd != null) {
3033 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3034 if (res != null) return res;
3035 }
3036 // No cached value available; request value from VM
3037 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3038 if (rd != null) {
3039 if (publicOnly) {
3040 rd.declaredPublicMethods = res;
3041 } else {
3042 rd.declaredMethods = res;
3043 }
3044 }
3045 return res;
3046 }
3047
3048 // Returns an array of "root" methods. These Method objects must NOT
3049 // be propagated to the outside world, but must instead be copied
3050 // via ReflectionFactory.copyMethod.
3051 private Method[] privateGetPublicMethods() {
3052 Method[] res;
3053 ReflectionData<T> rd = reflectionData();
3054 if (rd != null) {
3055 res = rd.publicMethods;
3056 if (res != null) return res;
3057 }
3058
3059 // No cached value available; compute value recursively.
3060 // Start by fetching public declared methods...
3061 PublicMethods pms = new PublicMethods();
3062 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3063 pms.merge(m);
3064 }
3065 // ...then recur over superclass methods...
3066 Class<?> sc = getSuperclass();
3067 if (sc != null) {
3068 for (Method m : sc.privateGetPublicMethods()) {
3069 pms.merge(m);
3070 }
3071 }
3072 // ...and finally over direct superinterfaces.
3073 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3074 for (Method m : intf.privateGetPublicMethods()) {
3075 // static interface methods are not inherited
3076 if (!Modifier.isStatic(m.getModifiers())) {
3077 pms.merge(m);
3078 }
3079 }
3080 }
3081
3082 res = pms.toArray();
3083 if (rd != null) {
3084 rd.publicMethods = res;
3085 }
3086 return res;
3087 }
3088
3089
3090 //
3091 // Helpers for fetchers of one field, method, or constructor
3092 //
3093
3094 // This method does not copy the returned Field object!
3095 private static Field searchFields(Field[] fields, String name) {
3096 for (Field field : fields) {
3097 if (field.getName().equals(name)) {
3098 return field;
3099 }
3100 }
3101 return null;
3102 }
3103
3104 // Returns a "root" Field object. This Field object must NOT
3105 // be propagated to the outside world, but must instead be copied
3106 // via ReflectionFactory.copyField.
3107 private Field getField0(String name) {
3108 // Note: the intent is that the search algorithm this routine
3109 // uses be equivalent to the ordering imposed by
3110 // privateGetPublicFields(). It fetches only the declared
3111 // public fields for each class, however, to reduce the number
3112 // of Field objects which have to be created for the common
3113 // case where the field being requested is declared in the
3114 // class which is being queried.
3115 Field res;
3116 // Search declared public fields
3117 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3118 return res;
3119 }
3120 // Direct superinterfaces, recursively
3121 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3122 for (Class<?> c : interfaces) {
3123 if ((res = c.getField0(name)) != null) {
3124 return res;
3125 }
3126 }
3127 // Direct superclass, recursively
3128 if (!isInterface()) {
3129 Class<?> c = getSuperclass();
3130 if (c != null) {
3131 if ((res = c.getField0(name)) != null) {
3132 return res;
3133 }
3134 }
3135 }
3136 return null;
3137 }
3138
3139 // This method does not copy the returned Method object!
3140 private static Method searchMethods(Method[] methods,
3141 String name,
3142 Class<?>[] parameterTypes)
3143 {
3144 ReflectionFactory fact = getReflectionFactory();
3145 Method res = null;
3146 for (Method m : methods) {
3147 if (m.getName().equals(name)
3148 && arrayContentsEq(parameterTypes,
3149 fact.getExecutableSharedParameterTypes(m))
3150 && (res == null
3151 || (res.getReturnType() != m.getReturnType()
3152 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3153 res = m;
3154 }
3155 return res;
3156 }
3157
3158 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3159
3160 // Returns a "root" Method object. This Method object must NOT
3161 // be propagated to the outside world, but must instead be copied
3162 // via ReflectionFactory.copyMethod.
3163 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3164 PublicMethods.MethodList res = getMethodsRecursive(
3165 name,
3166 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3167 /* includeStatic */ true, /* publicOnly */ true);
3168 return res == null ? null : res.getMostSpecific();
3169 }
3170
3171 // Returns a list of "root" Method objects. These Method objects must NOT
3172 // be propagated to the outside world, but must instead be copied
3173 // via ReflectionFactory.copyMethod.
3174 private PublicMethods.MethodList getMethodsRecursive(String name,
3175 Class<?>[] parameterTypes,
3176 boolean includeStatic,
3177 boolean publicOnly) {
3178 // 1st check declared methods
3179 Method[] methods = privateGetDeclaredMethods(publicOnly);
3180 PublicMethods.MethodList res = PublicMethods.MethodList
3181 .filter(methods, name, parameterTypes, includeStatic);
3182 // if there is at least one match among declared methods, we need not
3183 // search any further as such match surely overrides matching methods
3184 // declared in superclass(es) or interface(s).
3185 if (res != null) {
3186 return res;
3187 }
3188
3189 // if there was no match among declared methods,
3190 // we must consult the superclass (if any) recursively...
3191 Class<?> sc = getSuperclass();
3192 if (sc != null) {
3193 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3194 }
3195
3196 // ...and coalesce the superclass methods with methods obtained
3197 // from directly implemented interfaces excluding static methods...
3198 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3199 res = PublicMethods.MethodList.merge(
3200 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3201 }
3202
3203 return res;
3204 }
3205
3206 // Returns a "root" Constructor object. This Constructor object must NOT
3207 // be propagated to the outside world, but must instead be copied
3208 // via ReflectionFactory.copyConstructor.
3209 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3210 int which) throws NoSuchMethodException
3211 {
3212 ReflectionFactory fact = getReflectionFactory();
3213 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3214 for (Constructor<T> constructor : constructors) {
3215 if (arrayContentsEq(parameterTypes,
3216 fact.getExecutableSharedParameterTypes(constructor))) {
3217 return constructor;
3218 }
3219 }
3220 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3221 }
3222
3223 //
3224 // Other helpers and base implementation
3225 //
3226
3227 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3228 if (a1 == null) {
3229 return a2 == null || a2.length == 0;
3230 }
3231
3232 if (a2 == null) {
3233 return a1.length == 0;
3234 }
3235
3236 if (a1.length != a2.length) {
3237 return false;
3238 }
3239
3240 for (int i = 0; i < a1.length; i++) {
3241 if (a1[i] != a2[i]) {
3242 return false;
3243 }
3244 }
3245
3246 return true;
3247 }
3248
3249 private static Field[] copyFields(Field[] arg) {
3250 Field[] out = new Field[arg.length];
3251 ReflectionFactory fact = getReflectionFactory();
3252 for (int i = 0; i < arg.length; i++) {
3253 out[i] = fact.copyField(arg[i]);
3254 }
3255 return out;
3256 }
3257
3258 private static Method[] copyMethods(Method[] arg) {
3259 Method[] out = new Method[arg.length];
3260 ReflectionFactory fact = getReflectionFactory();
3261 for (int i = 0; i < arg.length; i++) {
3262 out[i] = fact.copyMethod(arg[i]);
3263 }
3264 return out;
3265 }
3266
3267 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3268 Constructor<U>[] out = arg.clone();
3269 ReflectionFactory fact = getReflectionFactory();
3270 for (int i = 0; i < out.length; i++) {
3271 out[i] = fact.copyConstructor(out[i]);
3272 }
3273 return out;
3274 }
3275
3276 private native Field[] getDeclaredFields0(boolean publicOnly);
3277 private native Method[] getDeclaredMethods0(boolean publicOnly);
3278 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3279 private native Class<?>[] getDeclaredClasses0();
3280
3281 /*
3282 * Returns an array containing the components of the Record attribute,
3283 * or null if the attribute is not present.
3284 *
3285 * Note that this method returns non-null array on a class with
3286 * the Record attribute even if this class is not a record.
3287 */
3288 private native RecordComponent[] getRecordComponents0();
3289 private native boolean isRecord0();
3290
3291 /**
3292 * Helper method to get the method name from arguments.
3293 */
3294 private String methodToString(String name, Class<?>[] argTypes) {
3295 return getName() + '.' + name +
3296 ((argTypes == null || argTypes.length == 0) ?
3297 "()" :
3298 Arrays.stream(argTypes)
3299 .map(c -> c == null ? "null" : c.getName())
3300 .collect(Collectors.joining(",", "(", ")")));
3301 }
3302
3303 /** use serialVersionUID from JDK 1.1 for interoperability */
3304 @java.io.Serial
3305 private static final long serialVersionUID = 3206093459760846163L;
3306
3307
3308 /**
3309 * Class Class is special cased within the Serialization Stream Protocol.
3310 *
3311 * A Class instance is written initially into an ObjectOutputStream in the
3312 * following format:
3313 * <pre>
3314 * {@code TC_CLASS} ClassDescriptor
3315 * A ClassDescriptor is a special cased serialization of
3316 * a {@code java.io.ObjectStreamClass} instance.
3317 * </pre>
3318 * A new handle is generated for the initial time the class descriptor
3319 * is written into the stream. Future references to the class descriptor
3320 * are written as references to the initial class descriptor instance.
3321 *
3322 * @see java.io.ObjectStreamClass
3323 */
3324 @java.io.Serial
3325 private static final ObjectStreamField[] serialPersistentFields =
3326 new ObjectStreamField[0];
3327
3328
3329 /**
3330 * Returns the assertion status that would be assigned to this
3331 * class if it were to be initialized at the time this method is invoked.
3332 * If this class has had its assertion status set, the most recent
3333 * setting will be returned; otherwise, if any package default assertion
3334 * status pertains to this class, the most recent setting for the most
3335 * specific pertinent package default assertion status is returned;
3336 * otherwise, if this class is not a system class (i.e., it has a
3337 * class loader) its class loader's default assertion status is returned;
3338 * otherwise, the system class default assertion status is returned.
3339 *
3340 * @apiNote
3341 * Few programmers will have any need for this method; it is provided
3342 * for the benefit of the JDK itself. (It allows a class to determine at
3343 * the time that it is initialized whether assertions should be enabled.)
3344 * Note that this method is not guaranteed to return the actual
3345 * assertion status that was (or will be) associated with the specified
3346 * class when it was (or will be) initialized.
3347 *
3348 * @return the desired assertion status of the specified class.
3349 * @see java.lang.ClassLoader#setClassAssertionStatus
3350 * @see java.lang.ClassLoader#setPackageAssertionStatus
3351 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3352 * @since 1.4
3353 */
3354 public boolean desiredAssertionStatus() {
3355 ClassLoader loader = classLoader;
3356 // If the loader is null this is a system class, so ask the VM
3357 if (loader == null)
3358 return desiredAssertionStatus0(this);
3359
3360 // If the classloader has been initialized with the assertion
3361 // directives, ask it. Otherwise, ask the VM.
3362 synchronized(loader.assertionLock) {
3363 if (loader.classAssertionStatus != null) {
3364 return loader.desiredAssertionStatus(getName());
3365 }
3366 }
3367 return desiredAssertionStatus0(this);
3368 }
3369
3370 // Retrieves the desired assertion status of this class from the VM
3371 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3372
3373 /**
3374 * Returns true if and only if this class was declared as an enum in the
3375 * source code.
3376 *
3377 * Note that {@link java.lang.Enum} is not itself an enum class.
3378 *
3379 * Also note that if an enum constant is declared with a class body,
3380 * the class of that enum constant object is an anonymous class
3381 * and <em>not</em> the class of the declaring enum class. The
3382 * {@link Enum#getDeclaringClass} method of an enum constant can
3383 * be used to get the class of the enum class declaring the
3384 * constant.
3385 *
3386 * @return true if and only if this class was declared as an enum in the
3387 * source code
3388 * @since 1.5
3389 * @jls 8.9.1 Enum Constants
3390 */
3391 public boolean isEnum() {
3392 // An enum must both directly extend java.lang.Enum and have
3393 // the ENUM bit set; classes for specialized enum constants
3394 // don't do the former.
3395 return (this.getModifiers() & ENUM) != 0 &&
3396 this.getSuperclass() == java.lang.Enum.class;
3397 }
3398
3399 /**
3400 * Returns {@code true} if and only if this class is a record class.
3401 *
3402 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3403 * class is {@code java.lang.Record}. A record class is {@linkplain
3404 * Modifier#FINAL final}. A record class has (possibly zero) record
3405 * components; {@link #getRecordComponents()} returns a non-null but
3406 * possibly empty value for a record.
3407 *
3408 * <p> Note that class {@link Record} is not a record class and thus
3409 * invoking this method on class {@code Record} returns {@code false}.
3410 *
3411 * @return true if and only if this class is a record class, otherwise false
3412 * @jls 8.10 Record Classes
3413 * @since 16
3414 */
3415 public boolean isRecord() {
3416 // this superclass and final modifier check is not strictly necessary
3417 // they are intrinsified and serve as a fast-path check
3418 return getSuperclass() == java.lang.Record.class &&
3419 (this.getModifiers() & Modifier.FINAL) != 0 &&
3420 isRecord0();
3421 }
3422
3423 // Fetches the factory for reflective objects
3424 private static ReflectionFactory getReflectionFactory() {
3425 var factory = reflectionFactory;
3426 if (factory != null) {
3427 return factory;
3428 }
3429 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3430 }
3431 private static ReflectionFactory reflectionFactory;
3432
3433 /**
3434 * When CDS is enabled, the Class class may be aot-initialized. However,
3435 * we can't archive reflectionFactory, so we reset it to null, so it
3436 * will be allocated again at runtime.
3437 */
3438 private static void resetArchivedStates() {
3439 reflectionFactory = null;
3440 }
3441
3442 /**
3443 * Returns the elements of this enum class or null if this
3444 * Class object does not represent an enum class.
3445 *
3446 * @return an array containing the values comprising the enum class
3447 * represented by this {@code Class} object in the order they're
3448 * declared, or null if this {@code Class} object does not
3449 * represent an enum class
3450 * @since 1.5
3451 * @jls 8.9.1 Enum Constants
3452 */
3453 public T[] getEnumConstants() {
3454 T[] values = getEnumConstantsShared();
3455 return (values != null) ? values.clone() : null;
3456 }
3457
3458 /**
3459 * Returns the elements of this enum class or null if this
3460 * Class object does not represent an enum class;
3461 * identical to getEnumConstants except that the result is
3462 * uncloned, cached, and shared by all callers.
3463 */
3464 T[] getEnumConstantsShared() {
3465 T[] constants = enumConstants;
3466 if (constants == null) {
3467 if (!isEnum()) return null;
3468 try {
3469 final Method values = getMethod("values");
3470 values.setAccessible(true);
3471 @SuppressWarnings("unchecked")
3472 T[] temporaryConstants = (T[])values.invoke(null);
3473 enumConstants = constants = temporaryConstants;
3474 }
3475 // These can happen when users concoct enum-like classes
3476 // that don't comply with the enum spec.
3477 catch (InvocationTargetException | NoSuchMethodException |
3478 IllegalAccessException | NullPointerException |
3479 ClassCastException ex) { return null; }
3480 }
3481 return constants;
3482 }
3483 private transient volatile T[] enumConstants;
3484
3485 /**
3486 * Returns a map from simple name to enum constant. This package-private
3487 * method is used internally by Enum to implement
3488 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3489 * efficiently. Note that the map is returned by this method is
3490 * created lazily on first use. Typically it won't ever get created.
3491 */
3492 Map<String, T> enumConstantDirectory() {
3493 Map<String, T> directory = enumConstantDirectory;
3494 if (directory == null) {
3495 T[] universe = getEnumConstantsShared();
3496 if (universe == null)
3497 throw new IllegalArgumentException(
3498 getName() + " is not an enum class");
3499 directory = HashMap.newHashMap(universe.length);
3500 for (T constant : universe) {
3501 directory.put(((Enum<?>)constant).name(), constant);
3502 }
3503 enumConstantDirectory = directory;
3504 }
3505 return directory;
3506 }
3507 private transient volatile Map<String, T> enumConstantDirectory;
3508
3509 /**
3510 * Casts an object to the class or interface represented
3511 * by this {@code Class} object.
3512 *
3513 * @param obj the object to be cast
3514 * @return the object after casting, or null if obj is null
3515 *
3516 * @throws ClassCastException if the object is not
3517 * null and is not assignable to the type T.
3518 *
3519 * @since 1.5
3520 */
3521 @SuppressWarnings("unchecked")
3522 @IntrinsicCandidate
3523 public T cast(Object obj) {
3524 if (obj != null && !isInstance(obj))
3525 throw new ClassCastException(cannotCastMsg(obj));
3526 return (T) obj;
3527 }
3528
3529 private String cannotCastMsg(Object obj) {
3530 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3531 }
3532
3533 /**
3534 * Casts this {@code Class} object to represent a subclass of the class
3535 * represented by the specified class object. Checks that the cast
3536 * is valid, and throws a {@code ClassCastException} if it is not. If
3537 * this method succeeds, it always returns a reference to this {@code Class} object.
3538 *
3539 * <p>This method is useful when a client needs to "narrow" the type of
3540 * a {@code Class} object to pass it to an API that restricts the
3541 * {@code Class} objects that it is willing to accept. A cast would
3542 * generate a compile-time warning, as the correctness of the cast
3543 * could not be checked at runtime (because generic types are implemented
3544 * by erasure).
3545 *
3546 * @param <U> the type to cast this {@code Class} object to
3547 * @param clazz the class of the type to cast this {@code Class} object to
3548 * @return this {@code Class} object, cast to represent a subclass of
3549 * the specified class object.
3550 * @throws ClassCastException if this {@code Class} object does not
3551 * represent a subclass of the specified class (here "subclass" includes
3552 * the class itself).
3553 * @since 1.5
3554 */
3555 @SuppressWarnings("unchecked")
3556 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3557 if (clazz.isAssignableFrom(this))
3558 return (Class<? extends U>) this;
3559 else
3560 throw new ClassCastException(this.toString());
3561 }
3562
3563 /**
3564 * {@inheritDoc}
3565 * <p>Note that any annotation returned by this method is a
3566 * declaration annotation.
3567 *
3568 * @throws NullPointerException {@inheritDoc}
3569 * @since 1.5
3570 */
3571 @Override
3572 @SuppressWarnings("unchecked")
3573 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3574 Objects.requireNonNull(annotationClass);
3575
3576 return (A) annotationData().annotations.get(annotationClass);
3577 }
3578
3579 /**
3580 * {@inheritDoc}
3581 * @throws NullPointerException {@inheritDoc}
3582 * @since 1.5
3583 */
3584 @Override
3585 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3586 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3587 }
3588
3589 /**
3590 * {@inheritDoc}
3591 * <p>Note that any annotations returned by this method are
3592 * declaration annotations.
3593 *
3594 * @throws NullPointerException {@inheritDoc}
3595 * @since 1.8
3596 */
3597 @Override
3598 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3599 Objects.requireNonNull(annotationClass);
3600
3601 AnnotationData annotationData = annotationData();
3602 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3603 this,
3604 annotationClass);
3605 }
3606
3607 /**
3608 * {@inheritDoc}
3609 * <p>Note that any annotations returned by this method are
3610 * declaration annotations.
3611 *
3612 * @since 1.5
3613 */
3614 @Override
3615 public Annotation[] getAnnotations() {
3616 return AnnotationParser.toArray(annotationData().annotations);
3617 }
3618
3619 /**
3620 * {@inheritDoc}
3621 * <p>Note that any annotation returned by this method is a
3622 * declaration annotation.
3623 *
3624 * @throws NullPointerException {@inheritDoc}
3625 * @since 1.8
3626 */
3627 @Override
3628 @SuppressWarnings("unchecked")
3629 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3630 Objects.requireNonNull(annotationClass);
3631
3632 return (A) annotationData().declaredAnnotations.get(annotationClass);
3633 }
3634
3635 /**
3636 * {@inheritDoc}
3637 * <p>Note that any annotations returned by this method are
3638 * declaration annotations.
3639 *
3640 * @throws NullPointerException {@inheritDoc}
3641 * @since 1.8
3642 */
3643 @Override
3644 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3645 Objects.requireNonNull(annotationClass);
3646
3647 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3648 annotationClass);
3649 }
3650
3651 /**
3652 * {@inheritDoc}
3653 * <p>Note that any annotations returned by this method are
3654 * declaration annotations.
3655 *
3656 * @since 1.5
3657 */
3658 @Override
3659 public Annotation[] getDeclaredAnnotations() {
3660 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3661 }
3662
3663 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3664 private static class AnnotationData {
3665 final Map<Class<? extends Annotation>, Annotation> annotations;
3666 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3667
3668 // Value of classRedefinedCount when we created this AnnotationData instance
3669 final int redefinedCount;
3670
3671 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3672 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3673 int redefinedCount) {
3674 this.annotations = annotations;
3675 this.declaredAnnotations = declaredAnnotations;
3676 this.redefinedCount = redefinedCount;
3677 }
3678 }
3679
3680 // Annotations cache
3681 @SuppressWarnings("UnusedDeclaration")
3682 private transient volatile AnnotationData annotationData;
3683
3684 private AnnotationData annotationData() {
3685 while (true) { // retry loop
3686 AnnotationData annotationData = this.annotationData;
3687 int classRedefinedCount = this.classRedefinedCount;
3688 if (annotationData != null &&
3689 annotationData.redefinedCount == classRedefinedCount) {
3690 return annotationData;
3691 }
3692 // null or stale annotationData -> optimistically create new instance
3693 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3694 // try to install it
3695 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3696 // successfully installed new AnnotationData
3697 return newAnnotationData;
3698 }
3699 }
3700 }
3701
3702 private AnnotationData createAnnotationData(int classRedefinedCount) {
3703 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3704 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3705 Class<?> superClass = getSuperclass();
3706 Map<Class<? extends Annotation>, Annotation> annotations = null;
3707 if (superClass != null) {
3708 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3709 superClass.annotationData().annotations;
3710 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3711 Class<? extends Annotation> annotationClass = e.getKey();
3712 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3713 if (annotations == null) { // lazy construction
3714 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3715 declaredAnnotations.size(),
3716 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3717 )
3718 );
3719 }
3720 annotations.put(annotationClass, e.getValue());
3721 }
3722 }
3723 }
3724 if (annotations == null) {
3725 // no inherited annotations -> share the Map with declaredAnnotations
3726 annotations = declaredAnnotations;
3727 } else {
3728 // at least one inherited annotation -> declared may override inherited
3729 annotations.putAll(declaredAnnotations);
3730 }
3731 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3732 }
3733
3734 // Annotation interfaces cache their internal (AnnotationType) form
3735
3736 @SuppressWarnings("UnusedDeclaration")
3737 private transient volatile AnnotationType annotationType;
3738
3739 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3740 return Atomic.casAnnotationType(this, oldType, newType);
3741 }
3742
3743 AnnotationType getAnnotationType() {
3744 return annotationType;
3745 }
3746
3747 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3748 return annotationData().declaredAnnotations;
3749 }
3750
3751 /* Backing store of user-defined values pertaining to this class.
3752 * Maintained by the ClassValue class.
3753 */
3754 transient ClassValue.ClassValueMap classValueMap;
3755
3756 /**
3757 * Returns an {@code AnnotatedType} object that represents the use of a
3758 * type to specify the superclass of the entity represented by this {@code
3759 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3760 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3761 * Foo.)
3762 *
3763 * <p> If this {@code Class} object represents a class whose declaration
3764 * does not explicitly indicate an annotated superclass, then the return
3765 * value is an {@code AnnotatedType} object representing an element with no
3766 * annotations.
3767 *
3768 * <p> If this {@code Class} represents either the {@code Object} class, an
3769 * interface type, an array type, a primitive type, or void, the return
3770 * value is {@code null}.
3771 *
3772 * @return an object representing the superclass
3773 * @since 1.8
3774 */
3775 public AnnotatedType getAnnotatedSuperclass() {
3776 if (this == Object.class ||
3777 isInterface() ||
3778 isArray() ||
3779 isPrimitive() ||
3780 this == Void.TYPE) {
3781 return null;
3782 }
3783
3784 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3785 }
3786
3787 /**
3788 * Returns an array of {@code AnnotatedType} objects that represent the use
3789 * of types to specify superinterfaces of the entity represented by this
3790 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3791 * superinterface in '... implements Foo' is distinct from the
3792 * <em>declaration</em> of interface Foo.)
3793 *
3794 * <p> If this {@code Class} object represents a class, the return value is
3795 * an array containing objects representing the uses of interface types to
3796 * specify interfaces implemented by the class. The order of the objects in
3797 * the array corresponds to the order of the interface types used in the
3798 * 'implements' clause of the declaration of this {@code Class} object.
3799 *
3800 * <p> If this {@code Class} object represents an interface, the return
3801 * value is an array containing objects representing the uses of interface
3802 * types to specify interfaces directly extended by the interface. The
3803 * order of the objects in the array corresponds to the order of the
3804 * interface types used in the 'extends' clause of the declaration of this
3805 * {@code Class} object.
3806 *
3807 * <p> If this {@code Class} object represents a class or interface whose
3808 * declaration does not explicitly indicate any annotated superinterfaces,
3809 * the return value is an array of length 0.
3810 *
3811 * <p> If this {@code Class} object represents either the {@code Object}
3812 * class, an array type, a primitive type, or void, the return value is an
3813 * array of length 0.
3814 *
3815 * @return an array representing the superinterfaces
3816 * @since 1.8
3817 */
3818 public AnnotatedType[] getAnnotatedInterfaces() {
3819 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3820 }
3821
3822 private native Class<?> getNestHost0();
3823
3824 /**
3825 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3826 * or interface represented by this {@code Class} object belongs.
3827 * Every class and interface belongs to exactly one nest.
3828 *
3829 * If the nest host of this class or interface has previously
3830 * been determined, then this method returns the nest host.
3831 * If the nest host of this class or interface has
3832 * not previously been determined, then this method determines the nest
3833 * host using the algorithm of JVMS 5.4.4, and returns it.
3834 *
3835 * Often, a class or interface belongs to a nest consisting only of itself,
3836 * in which case this method returns {@code this} to indicate that the class
3837 * or interface is the nest host.
3838 *
3839 * <p>If this {@code Class} object represents a primitive type, an array type,
3840 * or {@code void}, then this method returns {@code this},
3841 * indicating that the represented entity belongs to the nest consisting only of
3842 * itself, and is the nest host.
3843 *
3844 * @return the nest host of this class or interface
3845 *
3846 * @since 11
3847 * @jvms 4.7.28 The {@code NestHost} Attribute
3848 * @jvms 4.7.29 The {@code NestMembers} Attribute
3849 * @jvms 5.4.4 Access Control
3850 */
3851 public Class<?> getNestHost() {
3852 if (isPrimitive() || isArray()) {
3853 return this;
3854 }
3855 return getNestHost0();
3856 }
3857
3858 /**
3859 * Determines if the given {@code Class} is a nestmate of the
3860 * class or interface represented by this {@code Class} object.
3861 * Two classes or interfaces are nestmates
3862 * if they have the same {@linkplain #getNestHost() nest host}.
3863 *
3864 * @param c the class to check
3865 * @return {@code true} if this class and {@code c} are members of
3866 * the same nest; and {@code false} otherwise.
3867 *
3868 * @since 11
3869 */
3870 public boolean isNestmateOf(Class<?> c) {
3871 if (this == c) {
3872 return true;
3873 }
3874 if (isPrimitive() || isArray() ||
3875 c.isPrimitive() || c.isArray()) {
3876 return false;
3877 }
3878
3879 return getNestHost() == c.getNestHost();
3880 }
3881
3882 private native Class<?>[] getNestMembers0();
3883
3884 /**
3885 * Returns an array containing {@code Class} objects representing all the
3886 * classes and interfaces that are members of the nest to which the class
3887 * or interface represented by this {@code Class} object belongs.
3888 *
3889 * First, this method obtains the {@linkplain #getNestHost() nest host},
3890 * {@code H}, of the nest to which the class or interface represented by
3891 * this {@code Class} object belongs. The zeroth element of the returned
3892 * array is {@code H}.
3893 *
3894 * Then, for each class or interface {@code C} which is recorded by {@code H}
3895 * as being a member of its nest, this method attempts to obtain the {@code Class}
3896 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3897 * loader} of the current {@code Class} object), and then obtains the
3898 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3899 * The classes and interfaces which are recorded by {@code H} as being members
3900 * of its nest, and for which {@code H} can be determined as their nest host,
3901 * are indicated by subsequent elements of the returned array. The order of
3902 * such elements is unspecified. Duplicates are permitted.
3903 *
3904 * <p>If this {@code Class} object represents a primitive type, an array type,
3905 * or {@code void}, then this method returns a single-element array containing
3906 * {@code this}.
3907 *
3908 * @apiNote
3909 * The returned array includes only the nest members recorded in the {@code NestMembers}
3910 * attribute, and not any hidden classes that were added to the nest via
3911 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3912 * Lookup::defineHiddenClass}.
3913 *
3914 * @return an array of all classes and interfaces in the same nest as
3915 * this class or interface
3916 *
3917 * @since 11
3918 * @see #getNestHost()
3919 * @jvms 4.7.28 The {@code NestHost} Attribute
3920 * @jvms 4.7.29 The {@code NestMembers} Attribute
3921 */
3922 public Class<?>[] getNestMembers() {
3923 if (isPrimitive() || isArray()) {
3924 return new Class<?>[] { this };
3925 }
3926 Class<?>[] members = getNestMembers0();
3927 // Can't actually enable this due to bootstrapping issues
3928 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3929 return members;
3930 }
3931
3932 /**
3933 * Returns the descriptor string of the entity (class, interface, array class,
3934 * primitive type, or {@code void}) represented by this {@code Class} object.
3935 *
3936 * <p> If this {@code Class} object represents a class or interface,
3937 * not an array class, then:
3938 * <ul>
3939 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3940 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3941 * for the class or interface. Calling
3942 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3943 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3944 * describing this class or interface.
3945 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3946 * then the result is a string of the form:
3947 * <blockquote>
3948 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3949 * </blockquote>
3950 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3951 * encoded in internal form indicated by the {@code class} file passed to
3952 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3953 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3954 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3955 * The result string is not a type descriptor.
3956 * </ul>
3957 *
3958 * <p> If this {@code Class} object represents an array class, then
3959 * the result is a string consisting of one or more '{@code [}' characters
3960 * representing the depth of the array nesting, followed by the
3961 * descriptor string of the element type.
3962 * <ul>
3963 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3964 * or interface, then this array class can be described nominally.
3965 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3966 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3967 * describing this array class.
3968 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3969 * interface, then this array class cannot be described nominally.
3970 * The result string is not a type descriptor.
3971 * </ul>
3972 *
3973 * <p> If this {@code Class} object represents a primitive type or
3974 * {@code void}, then the result is a field descriptor string which
3975 * is a one-letter code corresponding to a primitive type or {@code void}
3976 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3977 *
3978 * @return the descriptor string for this {@code Class} object
3979 * @jvms 4.3.2 Field Descriptors
3980 * @since 12
3981 */
3982 @Override
3983 public String descriptorString() {
3984 if (isPrimitive())
3985 return Wrapper.forPrimitiveType(this).basicTypeString();
3986
3987 if (isArray()) {
3988 return "[".concat(componentType.descriptorString());
3989 } else if (isHidden()) {
3990 String name = getName();
3991 int index = name.indexOf('/');
3992 return new StringBuilder(name.length() + 2)
3993 .append('L')
3994 .append(name.substring(0, index).replace('.', '/'))
3995 .append('.')
3996 .append(name, index + 1, name.length())
3997 .append(';')
3998 .toString();
3999 } else {
4000 String name = getName().replace('.', '/');
4001 return StringConcatHelper.concat("L", name, ";");
4002 }
4003 }
4004
4005 /**
4006 * Returns the component type of this {@code Class}, if it describes
4007 * an array type, or {@code null} otherwise.
4008 *
4009 * @implSpec
4010 * Equivalent to {@link Class#getComponentType()}.
4011 *
4012 * @return a {@code Class} describing the component type, or {@code null}
4013 * if this {@code Class} does not describe an array type
4014 * @since 12
4015 */
4016 @Override
4017 public Class<?> componentType() {
4018 return isArray() ? componentType : null;
4019 }
4020
4021 /**
4022 * Returns a {@code Class} for an array type whose component type
4023 * is described by this {@linkplain Class}.
4024 *
4025 * @throws UnsupportedOperationException if this component type is {@linkplain
4026 * Void#TYPE void} or if the number of dimensions of the resulting array
4027 * type would exceed 255.
4028 * @return a {@code Class} describing the array type
4029 * @jvms 4.3.2 Field Descriptors
4030 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4031 * @since 12
4032 */
4033 @Override
4034 public Class<?> arrayType() {
4035 try {
4036 return Array.newInstance(this, 0).getClass();
4037 } catch (IllegalArgumentException iae) {
4038 throw new UnsupportedOperationException(iae);
4039 }
4040 }
4041
4042 /**
4043 * Returns a nominal descriptor for this instance, if one can be
4044 * constructed, or an empty {@link Optional} if one cannot be.
4045 *
4046 * @return An {@link Optional} containing the resulting nominal descriptor,
4047 * or an empty {@link Optional} if one cannot be constructed.
4048 * @since 12
4049 */
4050 @Override
4051 public Optional<ClassDesc> describeConstable() {
4052 Class<?> c = isArray() ? elementType() : this;
4053 return c.isHidden() ? Optional.empty()
4054 : Optional.of(ConstantUtils.classDesc(this));
4055 }
4056
4057 /**
4058 * Returns {@code true} if and only if the underlying class is a hidden class.
4059 *
4060 * @return {@code true} if and only if this class is a hidden class.
4061 *
4062 * @since 15
4063 * @see MethodHandles.Lookup#defineHiddenClass
4064 * @see Class##hiddenClasses Hidden Classes
4065 */
4066 @IntrinsicCandidate
4067 public native boolean isHidden();
4068
4069 /**
4070 * Returns an array containing {@code Class} objects representing the
4071 * direct subinterfaces or subclasses permitted to extend or
4072 * implement this class or interface if it is sealed. The order of such elements
4073 * is unspecified. The array is empty if this sealed class or interface has no
4074 * permitted subclass. If this {@code Class} object represents a primitive type,
4075 * {@code void}, an array type, or a class or interface that is not sealed,
4076 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4077 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4078 * returns a non-null value.
4079 *
4080 * For each class or interface {@code C} which is recorded as a permitted
4081 * direct subinterface or subclass of this class or interface,
4082 * this method attempts to obtain the {@code Class}
4083 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4084 * loader} of the current {@code Class} object).
4085 * The {@code Class} objects which can be obtained and which are direct
4086 * subinterfaces or subclasses of this class or interface,
4087 * are indicated by elements of the returned array. If a {@code Class} object
4088 * cannot be obtained, it is silently ignored, and not included in the result
4089 * array.
4090 *
4091 * @return an array of {@code Class} objects of the permitted subclasses of this class
4092 * or interface, or {@code null} if this class or interface is not sealed.
4093 *
4094 * @jls 8.1 Class Declarations
4095 * @jls 9.1 Interface Declarations
4096 * @since 17
4097 */
4098 public Class<?>[] getPermittedSubclasses() {
4099 Class<?>[] subClasses;
4100 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4101 return null;
4102 }
4103 if (subClasses.length > 0) {
4104 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4105 subClasses = Arrays.stream(subClasses)
4106 .filter(this::isDirectSubType)
4107 .toArray(s -> new Class<?>[s]);
4108 }
4109 }
4110 return subClasses;
4111 }
4112
4113 private boolean isDirectSubType(Class<?> c) {
4114 if (isInterface()) {
4115 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4116 if (i == this) {
4117 return true;
4118 }
4119 }
4120 } else {
4121 return c.getSuperclass() == this;
4122 }
4123 return false;
4124 }
4125
4126 /**
4127 * Returns {@code true} if and only if this {@code Class} object represents
4128 * a sealed class or interface. If this {@code Class} object represents a
4129 * primitive type, {@code void}, or an array type, this method returns
4130 * {@code false}. A sealed class or interface has (possibly zero) permitted
4131 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4132 * possibly empty value for a sealed class or interface.
4133 *
4134 * @return {@code true} if and only if this {@code Class} object represents
4135 * a sealed class or interface.
4136 *
4137 * @jls 8.1 Class Declarations
4138 * @jls 9.1 Interface Declarations
4139 * @since 17
4140 */
4141 public boolean isSealed() {
4142 if (isArray() || isPrimitive()) {
4143 return false;
4144 }
4145 return getPermittedSubclasses() != null;
4146 }
4147
4148 private native Class<?>[] getPermittedSubclasses0();
4149
4150 /*
4151 * Return the class's major and minor class file version packed into an int.
4152 * The high order 16 bits contain the class's minor version. The low order
4153 * 16 bits contain the class's major version.
4154 *
4155 * If the class is an array type then the class file version of its element
4156 * type is returned. If the class is a primitive type then the latest class
4157 * file major version is returned and zero is returned for the minor version.
4158 */
4159 private int getClassFileVersion() {
4160 Class<?> c = isArray() ? elementType() : this;
4161 return c.getClassFileVersion0();
4162 }
4163
4164 private native int getClassFileVersion0();
4165
4166 /*
4167 * Return the access flags as they were in the class's bytecode, including
4168 * the original setting of ACC_SUPER.
4169 *
4170 * If the class is an array type then the access flags of the element type is
4171 * returned. If the class is a primitive then ACC_ABSTRACT | ACC_FINAL | ACC_PUBLIC.
4172 */
4173 private int getClassAccessFlagsRaw() {
4174 Class<?> c = isArray() ? elementType() : this;
4175 return c.getClassAccessFlagsRaw0();
4176 }
4177
4178 private native int getClassAccessFlagsRaw0();
4179 }