1 /*
2 * Copyright (c) 1994, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import java.lang.annotation.Annotation;
29 import java.lang.constant.ClassDesc;
30 import java.lang.constant.ConstantDescs;
31 import java.lang.invoke.TypeDescriptor;
32 import java.lang.invoke.MethodHandles;
33 import java.lang.ref.SoftReference;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.ObjectStreamField;
37 import java.lang.reflect.AnnotatedElement;
38 import java.lang.reflect.AnnotatedType;
39 import java.lang.reflect.AccessFlag;
40 import java.lang.reflect.Array;
41 import java.lang.reflect.Constructor;
42 import java.lang.reflect.Executable;
43 import java.lang.reflect.Field;
44 import java.lang.reflect.GenericArrayType;
45 import java.lang.reflect.GenericDeclaration;
46 import java.lang.reflect.InvocationTargetException;
47 import java.lang.reflect.Member;
48 import java.lang.reflect.Method;
49 import java.lang.reflect.Modifier;
50 import java.lang.reflect.RecordComponent;
51 import java.lang.reflect.Type;
52 import java.lang.reflect.TypeVariable;
53 import java.lang.constant.Constable;
54 import java.net.URL;
55 import java.security.AllPermission;
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.LinkedHashMap;
63 import java.util.LinkedHashSet;
64 import java.util.List;
65 import java.util.Map;
66 import java.util.Objects;
67 import java.util.Optional;
68 import java.util.Set;
69 import java.util.stream.Collectors;
70
71 import jdk.internal.constant.ConstantUtils;
72 import jdk.internal.loader.BootLoader;
73 import jdk.internal.loader.BuiltinClassLoader;
74 import jdk.internal.misc.Unsafe;
75 import jdk.internal.module.Resources;
76 import jdk.internal.reflect.CallerSensitive;
77 import jdk.internal.reflect.CallerSensitiveAdapter;
78 import jdk.internal.reflect.ConstantPool;
79 import jdk.internal.reflect.Reflection;
80 import jdk.internal.reflect.ReflectionFactory;
81 import jdk.internal.util.ModifiedUtf;
82 import jdk.internal.vm.annotation.AOTRuntimeSetup;
83 import jdk.internal.vm.annotation.AOTSafeClassInitializer;
84 import jdk.internal.vm.annotation.IntrinsicCandidate;
85 import jdk.internal.vm.annotation.Stable;
86
87 import sun.invoke.util.BytecodeDescriptor;
88 import sun.invoke.util.Wrapper;
89 import sun.reflect.generics.factory.CoreReflectionFactory;
90 import sun.reflect.generics.factory.GenericsFactory;
91 import sun.reflect.generics.repository.ClassRepository;
92 import sun.reflect.generics.scope.ClassScope;
93 import sun.reflect.annotation.*;
94
95 /**
96 * Instances of the class {@code Class} represent classes and
97 * interfaces in a running Java application. An enum class and a record
98 * class are kinds of class; an annotation interface is a kind of
99 * interface. Every array also belongs to a class that is reflected as
100 * a {@code Class} object that is shared by all arrays with the same
101 * element type and number of dimensions. The primitive Java types
102 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
103 * int}, {@code long}, {@code float}, and {@code double}), and the
104 * keyword {@code void} are also represented as {@code Class} objects.
105 *
106 * <p> {@code Class} has no public constructor. Instead a {@code Class}
107 * object is constructed automatically by the Java Virtual Machine when
108 * a class is derived from the bytes of a {@code class} file through
109 * the invocation of one of the following methods:
110 * <ul>
111 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
112 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
113 * java.lang.invoke.MethodHandles.Lookup::defineClass}
114 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
115 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
116 * </ul>
117 *
118 * <p> The methods of class {@code Class} expose many characteristics of a
119 * class or interface. Most characteristics are derived from the {@code class}
120 * file that the class loader passed to the Java Virtual Machine or
121 * from the {@code class} file passed to {@code Lookup::defineClass}
122 * or {@code Lookup::defineHiddenClass}.
123 * A few characteristics are determined by the class loading environment
124 * at run time, such as the module returned by {@link #getModule() getModule()}.
125 *
126 * <p> The following example uses a {@code Class} object to print the
127 * class name of an object:
128 *
129 * {@snippet lang="java" :
130 * void printClassName(Object obj) {
131 * System.out.println("The class of " + obj +
132 * " is " + obj.getClass().getName());
133 * }}
134 *
135 * It is also possible to get the {@code Class} object for a named
136 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
137 * (JLS {@jls 15.8.2}).
138 * For example:
139 *
140 * {@snippet lang="java" :
141 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
142 * }
143 *
144 * <p> Some methods of class {@code Class} expose whether the declaration of
145 * a class or interface in Java source code was <em>enclosed</em> within
146 * another declaration. Other methods describe how a class or interface
147 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
148 * classes and interfaces, in the same run-time package, that
149 * allow mutual access to their {@code private} members.
150 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
151 * (JVMS {@jvms 4.7.29}).
152 * One nestmate acts as the
153 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
154 * belong to the nest; each of them in turn records it as the nest host.
155 * The classes and interfaces which belong to a nest, including its host, are
156 * determined when
157 * {@code class} files are generated, for example, a Java compiler
158 * will typically record a top-level class as the host of a nest where the
159 * other members are the classes and interfaces whose declarations are
160 * enclosed within the top-level class declaration.
161 *
162 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
163 * A class or interface created by the invocation of
164 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
165 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
166 * class or interface.
167 * All kinds of class, including enum classes and record classes, may be
168 * hidden classes; all kinds of interface, including annotation interfaces,
169 * may be hidden interfaces.
170 *
171 * The {@linkplain #getName() name of a hidden class or interface} is
172 * not a {@linkplain ClassLoader##binary-name binary name},
173 * which means the following:
174 * <ul>
175 * <li>A hidden class or interface cannot be referenced by the constant pools
176 * of other classes and interfaces.
177 * <li>A hidden class or interface cannot be described in
178 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
179 * {@link #describeConstable() Class::describeConstable},
180 * {@link ClassDesc#of(String) ClassDesc::of}, or
181 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
182 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
183 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
184 * </ul>
185 *
186 * A hidden class or interface is never an array class, but may be
187 * the element type of an array. In all other respects, the fact that
188 * a class or interface is hidden has no bearing on the characteristics
189 * exposed by the methods of class {@code Class}.
190 *
191 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
192 *
193 * Conventionally, a Java compiler, starting from a source file for an
194 * implicitly declared class, say {@code HelloWorld.java}, creates a
195 * similarly-named {@code class} file, {@code HelloWorld.class}, where
196 * the class stored in that {@code class} file is named {@code
197 * "HelloWorld"}, matching the base names of the source and {@code
198 * class} files.
199 *
200 * For the {@code Class} object of an implicitly declared class {@code
201 * HelloWorld}, the methods to get the {@linkplain #getName name} and
202 * {@linkplain #getTypeName type name} return results
203 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
204 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
205 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
206 *
207 * @param <T> the type of the class modeled by this {@code Class}
208 * object. For example, the type of {@code String.class} is {@code
209 * Class<String>}. Use {@code Class<?>} if the class being modeled is
210 * unknown.
211 *
212 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
213 * @since 1.0
214 */
215 @AOTSafeClassInitializer
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 /// No significant static final fields; [#resetArchivedStates()] handles
232 /// prevents storing [#reflectionFactory] into AOT image.
233 @AOTRuntimeSetup
234 private static void runtimeSetup() {
235 registerNatives();
236 }
237
238 /*
239 * Private constructor. Only the Java Virtual Machine creates Class objects.
240 * This constructor is not used and prevents the default constructor being
241 * generated.
242 */
243 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, char flags) {
244 // Initialize final field for classLoader. The initialization value of non-null
245 // prevents future JIT optimizations from assuming this final field is null.
246 // The following assignments are done directly by the VM without calling this constructor.
247 classLoader = loader;
248 componentType = arrayComponentType;
249 modifiers = mods;
250 protectionDomain = pd;
251 primitive = isPrim;
252 classFileAccessFlags = flags;
253 }
254
255 /**
256 * Converts the object to a string. The string representation is the
257 * string "class" or "interface", followed by a space, and then by the
258 * name of the class in the format returned by {@code getName}.
259 * If this {@code Class} object represents a primitive type,
260 * this method returns the name of the primitive type. If
261 * this {@code Class} object represents void this method returns
262 * "void". If this {@code Class} object represents an array type,
263 * this method returns "class " followed by {@code getName}.
264 *
265 * @return a string representation of this {@code Class} object.
266 */
267 public String toString() {
268 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
269 return kind.concat(getName());
270 }
271
272 /**
273 * Returns a string describing this {@code Class}, including
274 * information about modifiers, {@link #isSealed() sealed}/{@code
275 * non-sealed} status, and type parameters.
276 *
277 * The string is formatted as a list of type modifiers, if any,
278 * followed by the kind of type (empty string for primitive types
279 * and {@code class}, {@code enum}, {@code interface},
280 * {@code @interface}, or {@code record} as appropriate), followed
281 * by the type's name, followed by an angle-bracketed
282 * comma-separated list of the type's type parameters, if any,
283 * including informative bounds on the type parameters, if any.
284 *
285 * A space is used to separate modifiers from one another and to
286 * separate any modifiers from the kind of type. The modifiers
287 * occur in canonical order. If there are no type parameters, the
288 * type parameter list is elided.
289 *
290 * For an array type, the string starts with the type name,
291 * followed by an angle-bracketed comma-separated list of the
292 * type's type parameters, if any, followed by a sequence of
293 * {@code []} characters, one set of brackets per dimension of
294 * the array.
295 *
296 * <p>Note that since information about the runtime representation
297 * of a type is being generated, modifiers not present on the
298 * originating source code or illegal on the originating source
299 * code may be present.
300 *
301 * @return a string describing this {@code Class}, including
302 * information about modifiers and type parameters
303 *
304 * @since 1.8
305 */
306 public String toGenericString() {
307 if (isPrimitive()) {
308 return toString();
309 } else {
310 StringBuilder sb = new StringBuilder();
311 Class<?> component = this;
312 int arrayDepth = 0;
313
314 if (isArray()) {
315 do {
316 arrayDepth++;
317 component = component.getComponentType();
318 } while (component.isArray());
319 sb.append(component.getName());
320 } else {
321 // Class modifiers are a superset of interface modifiers
322 int modifiers = getModifiers() & Modifier.classModifiers();
323 if (modifiers != 0) {
324 sb.append(Modifier.toString(modifiers));
325 sb.append(' ');
326 }
327
328 // A class cannot be strictfp and sealed/non-sealed so
329 // it is sufficient to check for sealed-ness after all
330 // modifiers are printed.
331 addSealingInfo(modifiers, sb);
332
333 if (isAnnotation()) {
334 sb.append('@');
335 }
336 if (isInterface()) { // Note: all annotation interfaces are interfaces
337 sb.append("interface");
338 } else {
339 if (isEnum())
340 sb.append("enum");
341 else if (isRecord())
342 sb.append("record");
343 else
344 sb.append("class");
345 }
346 sb.append(' ');
347 sb.append(getName());
348 }
349
350 TypeVariable<?>[] typeparms = component.getTypeParameters();
351 if (typeparms.length > 0) {
352 sb.append(Arrays.stream(typeparms)
353 .map(Class::typeVarBounds)
354 .collect(Collectors.joining(",", "<", ">")));
355 }
356
357 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
358
359 return sb.toString();
360 }
361 }
362
363 private void addSealingInfo(int modifiers, StringBuilder sb) {
364 // A class can be final XOR sealed XOR non-sealed.
365 if (Modifier.isFinal(modifiers)) {
366 return; // no-op
367 } else {
368 if (isSealed()) {
369 sb.append("sealed ");
370 return;
371 } else {
372 // Check for sealed ancestor, which implies this class
373 // is non-sealed.
374 if (hasSealedAncestor(this)) {
375 sb.append("non-sealed ");
376 }
377 }
378 }
379 }
380
381 private boolean hasSealedAncestor(Class<?> clazz) {
382 // From JLS 8.1.1.2:
383 // "It is a compile-time error if a class has a sealed direct
384 // superclass or a sealed direct superinterface, and is not
385 // declared final, sealed, or non-sealed either explicitly or
386 // implicitly.
387 // Thus, an effect of the sealed keyword is to force all
388 // direct subclasses to explicitly declare whether they are
389 // final, sealed, or non-sealed. This avoids accidentally
390 // exposing a sealed class hierarchy to unwanted subclassing."
391
392 // Therefore, will just check direct superclass and
393 // superinterfaces.
394 var superclass = clazz.getSuperclass();
395 if (superclass != null && superclass.isSealed()) {
396 return true;
397 }
398 for (var superinterface : clazz.getInterfaces()) {
399 if (superinterface.isSealed()) {
400 return true;
401 }
402 }
403 return false;
404 }
405
406 static String typeVarBounds(TypeVariable<?> typeVar) {
407 Type[] bounds = typeVar.getBounds();
408 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
409 return typeVar.getName();
410 } else {
411 return typeVar.getName() + " extends " +
412 Arrays.stream(bounds)
413 .map(Type::getTypeName)
414 .collect(Collectors.joining(" & "));
415 }
416 }
417
418 /**
419 * Returns the {@code Class} object associated with the class or
420 * interface with the given string name. Invoking this method is
421 * equivalent to:
422 *
423 * {@snippet lang="java" :
424 * Class.forName(className, true, currentLoader)
425 * }
426 *
427 * where {@code currentLoader} denotes the defining class loader of
428 * the current class.
429 *
430 * <p> For example, the following code fragment returns the
431 * runtime {@code Class} object for the class named
432 * {@code java.lang.Thread}:
433 *
434 * {@snippet lang="java" :
435 * Class<?> t = Class.forName("java.lang.Thread");
436 * }
437 * <p>
438 * A call to {@code forName("X")} causes the class named
439 * {@code X} to be initialized.
440 *
441 * <p>
442 * In cases where this method is called from a context where there is no
443 * caller frame on the stack (e.g. when called directly from a JNI
444 * attached thread), the system class loader is used.
445 *
446 * @param className the {@linkplain ClassLoader##binary-name binary name}
447 * of the class or the string representing an array type
448 * @return the {@code Class} object for the class with the
449 * specified name.
450 * @throws LinkageError if the linkage fails
451 * @throws ExceptionInInitializerError if the initialization provoked
452 * by this method fails
453 * @throws ClassNotFoundException if the class cannot be located
454 *
455 * @jls 12.2 Loading of Classes and Interfaces
456 * @jls 12.3 Linking of Classes and Interfaces
457 * @jls 12.4 Initialization of Classes and Interfaces
458 */
459 @CallerSensitive
460 public static Class<?> forName(String className)
461 throws ClassNotFoundException {
462 Class<?> caller = Reflection.getCallerClass();
463 return forName(className, caller);
464 }
465
466 // Caller-sensitive adapter method for reflective invocation
467 @CallerSensitiveAdapter
468 private static Class<?> forName(String className, Class<?> caller)
469 throws ClassNotFoundException {
470 validateClassNameLength(className);
471 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
472 : ClassLoader.getClassLoader(caller);
473 if (loader instanceof BuiltinClassLoader bcl) {
474 if (bcl.usePositiveCache) {
475 Class<?> result = bcl.checkPositiveLookupCache(className);
476 if (result != null) {
477 // forName(String, Class) API will always initialize the class
478 Unsafe.getUnsafe().ensureClassInitialized(result);
479 return result;
480 }
481 }
482 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(className)) {
483 throw new ClassNotFoundException(className);
484 }
485 }
486 return forName0(className, true, loader);
487 }
488
489 /**
490 * Returns the {@code Class} object associated with the class or
491 * interface with the given string name, using the given class loader.
492 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
493 * this method attempts to locate and load the class or interface. The specified
494 * class loader is used to load the class or interface. If the parameter
495 * {@code loader} is {@code null}, the class is loaded through the bootstrap
496 * class loader. The class is initialized only if the
497 * {@code initialize} parameter is {@code true} and if it has
498 * not been initialized earlier.
499 *
500 * <p> This method cannot be used to obtain any of the {@code Class} objects
501 * representing primitive types or void, hidden classes or interfaces,
502 * or array classes whose element type is a hidden class or interface.
503 * If {@code name} denotes a primitive type or void, for example {@code I},
504 * an attempt will be made to locate a user-defined class in the unnamed package
505 * whose name is {@code I} instead.
506 * To obtain a {@code Class} object for a named primitive type
507 * such as {@code int} or {@code long} use {@link
508 * #forPrimitiveName(String)}.
509 *
510 * <p> To obtain the {@code Class} object associated with an array class,
511 * the name consists of one or more {@code '['} representing the depth
512 * of the array nesting, followed by the element type as encoded in
513 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
514 *
515 * <p> Examples:
516 * {@snippet lang="java" :
517 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
518 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
519 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
520 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
521 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
522 * }
523 *
524 * <p> A call to {@code getName()} on the {@code Class} object returned
525 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
526 *
527 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
528 * named <i>N</i> to be loaded but not initialized regardless of the value
529 * of the {@code initialize} parameter.
530 *
531 * @apiNote
532 * This method throws errors related to loading, linking or initializing
533 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
534 * <cite>The Java Language Specification</cite>.
535 * In addition, this method does not check whether the requested class
536 * is accessible to its caller.
537 *
538 * @param name the {@linkplain ClassLoader##binary-name binary name}
539 * of the class or the string representing an array class
540 *
541 * @param initialize if {@code true} the class will be initialized
542 * (which implies linking). See Section {@jls
543 * 12.4} of <cite>The Java Language
544 * Specification</cite>.
545 * @param loader class loader from which the class must be loaded
546 * @return class object representing the desired class
547 *
548 * @throws LinkageError if the linkage fails
549 * @throws ExceptionInInitializerError if the initialization provoked
550 * by this method fails
551 * @throws ClassNotFoundException if the class cannot be located by
552 * the specified class loader
553 *
554 * @see java.lang.Class#forName(String)
555 * @see java.lang.ClassLoader
556 *
557 * @jls 12.2 Loading of Classes and Interfaces
558 * @jls 12.3 Linking of Classes and Interfaces
559 * @jls 12.4 Initialization of Classes and Interfaces
560 * @jls 13.1 The Form of a Binary
561 * @since 1.2
562 */
563 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
564 throws ClassNotFoundException
565 {
566 validateClassNameLength(name);
567
568 if (loader instanceof BuiltinClassLoader bcl) {
569 if (bcl.usePositiveCache) {
570 Class<?> result = bcl.checkPositiveLookupCache(name);
571 if (result != null) {
572 if (initialize) {
573 Unsafe.getUnsafe().ensureClassInitialized(result);
574 }
575 return result;
576 }
577 }
578 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(name)) {
579 throw new ClassNotFoundException(name);
580 }
581 }
582
583 return forName0(name, initialize, loader);
584 }
585
586 /** Called after security check for system loader access checks have been made. */
587 private static native Class<?> forName0(String name, boolean initialize,
588 ClassLoader loader)
589 throws ClassNotFoundException;
590
591
592 /**
593 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
594 * binary name} in the given module.
595 *
596 * <p> This method attempts to locate and load the class or interface.
597 * It does not link the class, and does not run the class initializer.
598 * If the class is not found, this method returns {@code null}. </p>
599 *
600 * <p> If the class loader of the given module defines other modules and
601 * the given name is a class defined in a different module, this method
602 * returns {@code null} after the class is loaded. </p>
603 *
604 * <p> This method does not check whether the requested class is
605 * accessible to its caller. </p>
606 *
607 * @apiNote
608 * This method does not support loading of array types, unlike
609 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
610 * a binary name. This method returns {@code null} on failure rather than
611 * throwing a {@link ClassNotFoundException}, as is done by
612 * the {@link #forName(String, boolean, ClassLoader)} method.
613 *
614 * @param module A module
615 * @param name The {@linkplain ClassLoader##binary-name binary name}
616 * of the class
617 * @return {@code Class} object of the given name defined in the given module;
618 * {@code null} if not found.
619 *
620 * @throws NullPointerException if the given module or name is {@code null}
621 *
622 * @throws LinkageError if the linkage fails
623 *
624 * @jls 12.2 Loading of Classes and Interfaces
625 * @jls 12.3 Linking of Classes and Interfaces
626 * @since 9
627 */
628 public static Class<?> forName(Module module, String name) {
629 Objects.requireNonNull(module);
630 Objects.requireNonNull(name);
631 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
632 return null;
633 }
634
635 ClassLoader cl = module.getClassLoader();
636 if (cl != null) {
637 return cl.loadClass(module, name);
638 } else {
639 return BootLoader.loadClass(module, name);
640 }
641 }
642
643 /**
644 * {@return the {@code Class} object associated with the
645 * {@linkplain #isPrimitive() primitive type} of the given name}
646 * If the argument is not the name of a primitive type, {@code
647 * null} is returned.
648 *
649 * @param primitiveName the name of the primitive type to find
650 *
651 * @throws NullPointerException if the argument is {@code null}
652 *
653 * @jls 4.2 Primitive Types and Values
654 * @jls 15.8.2 Class Literals
655 * @since 22
656 */
657 public static Class<?> forPrimitiveName(String primitiveName) {
658 return switch(primitiveName) {
659 // Integral types
660 case "int" -> int.class;
661 case "long" -> long.class;
662 case "short" -> short.class;
663 case "char" -> char.class;
664 case "byte" -> byte.class;
665
666 // Floating-point types
667 case "float" -> float.class;
668 case "double" -> double.class;
669
670 // Other types
671 case "boolean" -> boolean.class;
672 case "void" -> void.class;
673
674 default -> null;
675 };
676 }
677
678 /**
679 * Creates a new instance of the class represented by this {@code Class}
680 * object. The class is instantiated as if by a {@code new}
681 * expression with an empty argument list. The class is initialized if it
682 * has not already been initialized.
683 *
684 * @deprecated This method propagates any exception thrown by the
685 * nullary constructor, including a checked exception. Use of
686 * this method effectively bypasses the compile-time exception
687 * checking that would otherwise be performed by the compiler.
688 * The {@link
689 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
690 * Constructor.newInstance} method avoids this problem by wrapping
691 * any exception thrown by the constructor in a (checked) {@link
692 * java.lang.reflect.InvocationTargetException}.
693 *
694 * <p>The call
695 *
696 * {@snippet lang="java" :
697 * clazz.newInstance()
698 * }
699 *
700 * can be replaced by
701 *
702 * {@snippet lang="java" :
703 * clazz.getDeclaredConstructor().newInstance()
704 * }
705 *
706 * The latter sequence of calls is inferred to be able to throw
707 * the additional exception types {@link
708 * InvocationTargetException} and {@link
709 * NoSuchMethodException}. Both of these exception types are
710 * subclasses of {@link ReflectiveOperationException}.
711 *
712 * @return a newly allocated instance of the class represented by this
713 * object.
714 * @throws IllegalAccessException if the class or its nullary
715 * constructor is not accessible.
716 * @throws InstantiationException
717 * if this {@code Class} represents an abstract class,
718 * an interface, an array class, a primitive type, or void;
719 * or if the class has no nullary constructor;
720 * or if the instantiation fails for some other reason.
721 * @throws ExceptionInInitializerError if the initialization
722 * provoked by this method fails.
723 */
724 @CallerSensitive
725 @Deprecated(since="9")
726 public T newInstance()
727 throws InstantiationException, IllegalAccessException
728 {
729 // Constructor lookup
730 Constructor<T> tmpConstructor = cachedConstructor;
731 if (tmpConstructor == null) {
732 if (this == Class.class) {
733 throw new IllegalAccessException(
734 "Can not call newInstance() on the Class for java.lang.Class"
735 );
736 }
737 try {
738 Class<?>[] empty = {};
739 final Constructor<T> c = getReflectionFactory().copyConstructor(
740 getConstructor0(empty, Member.DECLARED));
741 // Disable accessibility checks on the constructor
742 // access check is done with the true caller
743 c.setAccessible(true);
744 cachedConstructor = tmpConstructor = c;
745 } catch (NoSuchMethodException e) {
746 throw (InstantiationException)
747 new InstantiationException(getName()).initCause(e);
748 }
749 }
750
751 try {
752 Class<?> caller = Reflection.getCallerClass();
753 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
754 } catch (InvocationTargetException e) {
755 Unsafe.getUnsafe().throwException(e.getTargetException());
756 // Not reached
757 return null;
758 }
759 }
760
761 private transient volatile Constructor<T> cachedConstructor;
762
763 /**
764 * Determines if the specified {@code Object} is assignment-compatible
765 * with the object represented by this {@code Class}. This method is
766 * the dynamic equivalent of the Java language {@code instanceof}
767 * operator. The method returns {@code true} if the specified
768 * {@code Object} argument is non-null and can be cast to the
769 * reference type represented by this {@code Class} object without
770 * raising a {@code ClassCastException.} It returns {@code false}
771 * otherwise.
772 *
773 * <p> Specifically, if this {@code Class} object represents a
774 * declared class, this method returns {@code true} if the specified
775 * {@code Object} argument is an instance of the represented class (or
776 * of any of its subclasses); it returns {@code false} otherwise. If
777 * this {@code Class} object represents an array class, this method
778 * returns {@code true} if the specified {@code Object} argument
779 * can be converted to an object of the array class by an identity
780 * conversion or by a widening reference conversion; it returns
781 * {@code false} otherwise. If this {@code Class} object
782 * represents an interface, this method returns {@code true} if the
783 * class or any superclass of the specified {@code Object} argument
784 * implements this interface; it returns {@code false} otherwise. If
785 * this {@code Class} object represents a primitive type, this method
786 * returns {@code false}.
787 *
788 * @param obj the object to check
789 * @return true if {@code obj} is an instance of this class
790 *
791 * @since 1.1
792 */
793 @IntrinsicCandidate
794 public native boolean isInstance(Object obj);
795
796
797 /**
798 * Determines if the class or interface represented by this
799 * {@code Class} object is either the same as, or is a superclass or
800 * superinterface of, the class or interface represented by the specified
801 * {@code Class} parameter. It returns {@code true} if so;
802 * otherwise it returns {@code false}. If this {@code Class}
803 * object represents a primitive type, this method returns
804 * {@code true} if the specified {@code Class} parameter is
805 * exactly this {@code Class} object; otherwise it returns
806 * {@code false}.
807 *
808 * <p> Specifically, this method tests whether the type represented by the
809 * specified {@code Class} parameter can be converted to the type
810 * represented by this {@code Class} object via an identity conversion
811 * or via a widening reference conversion. See <cite>The Java Language
812 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
813 * for details.
814 *
815 * @param cls the {@code Class} object to be checked
816 * @return the {@code boolean} value indicating whether objects of the
817 * type {@code cls} can be assigned to objects of this class
818 * @throws NullPointerException if the specified Class parameter is
819 * null.
820 * @since 1.1
821 */
822 @IntrinsicCandidate
823 public native boolean isAssignableFrom(Class<?> cls);
824
825
826 /**
827 * Determines if this {@code Class} object represents an
828 * interface type.
829 *
830 * @return {@code true} if this {@code Class} object represents an interface;
831 * {@code false} otherwise.
832 */
833 public boolean isInterface() {
834 return Modifier.isInterface(modifiers);
835 }
836
837
838 /**
839 * Determines if this {@code Class} object represents an array class.
840 *
841 * @return {@code true} if this {@code Class} object represents an array class;
842 * {@code false} otherwise.
843 * @since 1.1
844 */
845 public boolean isArray() {
846 return componentType != null;
847 }
848
849
850 /**
851 * Determines if this {@code Class} object represents a primitive
852 * type or void.
853 *
854 * <p> There are nine predefined {@code Class} objects to
855 * represent the eight primitive types and void. These are
856 * created by the Java Virtual Machine, and have the same
857 * {@linkplain #getName() names} as the primitive types that they
858 * represent, namely {@code boolean}, {@code byte}, {@code char},
859 * {@code short}, {@code int}, {@code long}, {@code float}, and
860 * {@code double}.
861 *
862 * <p>No other class objects are considered primitive.
863 *
864 * @apiNote
865 * A {@code Class} object represented by a primitive type can be
866 * accessed via the {@code TYPE} public static final variables
867 * defined in the primitive wrapper classes such as {@link
868 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
869 * language, the objects may be referred to by a class literal
870 * expression such as {@code int.class}. The {@code Class} object
871 * for void can be expressed as {@code void.class} or {@link
872 * java.lang.Void#TYPE Void.TYPE}.
873 *
874 * @return true if and only if this class represents a primitive type
875 *
876 * @see java.lang.Boolean#TYPE
877 * @see java.lang.Character#TYPE
878 * @see java.lang.Byte#TYPE
879 * @see java.lang.Short#TYPE
880 * @see java.lang.Integer#TYPE
881 * @see java.lang.Long#TYPE
882 * @see java.lang.Float#TYPE
883 * @see java.lang.Double#TYPE
884 * @see java.lang.Void#TYPE
885 * @since 1.1
886 * @jls 15.8.2 Class Literals
887 */
888 public boolean isPrimitive() {
889 return primitive;
890 }
891
892 /**
893 * Returns true if this {@code Class} object represents an annotation
894 * interface. Note that if this method returns true, {@link #isInterface()}
895 * would also return true, as all annotation interfaces are also interfaces.
896 *
897 * @return {@code true} if this {@code Class} object represents an annotation
898 * interface; {@code false} otherwise
899 * @since 1.5
900 */
901 public boolean isAnnotation() {
902 return (getModifiers() & ANNOTATION) != 0;
903 }
904
905 /**
906 *{@return {@code true} if and only if this class has the synthetic modifier
907 * bit set}
908 *
909 * @jls 13.1 The Form of a Binary
910 * @jvms 4.1 The {@code ClassFile} Structure
911 * @see <a
912 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
913 * programming language and JVM modeling in core reflection</a>
914 * @since 1.5
915 */
916 public boolean isSynthetic() {
917 return (getModifiers() & SYNTHETIC) != 0;
918 }
919
920 /**
921 * Returns the name of the entity (class, interface, array class,
922 * primitive type, or void) represented by this {@code Class} object.
923 *
924 * <p> If this {@code Class} object represents a class or interface,
925 * not an array class, then:
926 * <ul>
927 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
928 * then the {@linkplain ClassLoader##binary-name binary name}
929 * of the class or interface is returned.
930 * <li> If the class or interface is hidden, then the result is a string
931 * of the form: {@code N + '/' + <suffix>}
932 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
933 * indicated by the {@code class} file passed to
934 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
935 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
936 * </ul>
937 *
938 * <p> If this {@code Class} object represents an array class, then
939 * the result is a string consisting of one or more '{@code [}' characters
940 * representing the depth of the array nesting, followed by the element
941 * type as encoded using the following table:
942 *
943 * <blockquote><table class="striped" id="nameFormat">
944 * <caption style="display:none">Element types and encodings</caption>
945 * <thead>
946 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
947 * </thead>
948 * <tbody style="text-align:left">
949 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
950 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
951 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
952 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
953 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
954 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
955 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
956 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
957 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
958 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
959 * </tbody>
960 * </table></blockquote>
961 *
962 * <p> If this {@code Class} object represents a primitive type or {@code void},
963 * then the result is a string with the same spelling as the Java language
964 * keyword which corresponds to the primitive type or {@code void}.
965 *
966 * <p> Examples:
967 * <blockquote><pre>
968 * String.class.getName()
969 * returns "java.lang.String"
970 * Character.UnicodeBlock.class.getName()
971 * returns "java.lang.Character$UnicodeBlock"
972 * byte.class.getName()
973 * returns "byte"
974 * (new Object[3]).getClass().getName()
975 * returns "[Ljava.lang.Object;"
976 * (new int[3][4][5][6][7][8][9]).getClass().getName()
977 * returns "[[[[[[[I"
978 * </pre></blockquote>
979 *
980 * @apiNote
981 * Distinct class objects can have the same name but different class loaders.
982 *
983 * @return the name of the class, interface, or other entity
984 * represented by this {@code Class} object.
985 * @jls 13.1 The Form of a Binary
986 */
987 public String getName() {
988 String name = this.name;
989 return name != null ? name : initClassName();
990 }
991
992 // Cache the name to reduce the number of calls into the VM.
993 // This field would be set by VM itself during initClassName call.
994 private transient String name;
995 private native String initClassName();
996
997 /**
998 * Returns the class loader for the class. Some implementations may use
999 * null to represent the bootstrap class loader. This method will return
1000 * null in such implementations if this class was loaded by the bootstrap
1001 * class loader.
1002 *
1003 * <p>If this {@code Class} object
1004 * represents a primitive type or void, null is returned.
1005 *
1006 * @return the class loader that loaded the class or interface
1007 * represented by this {@code Class} object.
1008 * @see java.lang.ClassLoader
1009 */
1010 public ClassLoader getClassLoader() {
1011 return classLoader;
1012 }
1013
1014 // Package-private to allow ClassLoader access
1015 ClassLoader getClassLoader0() { return classLoader; }
1016
1017 /**
1018 * Returns the module that this class or interface is a member of.
1019 *
1020 * If this class represents an array type then this method returns the
1021 * {@code Module} for the element type. If this class represents a
1022 * primitive type or void, then the {@code Module} object for the
1023 * {@code java.base} module is returned.
1024 *
1025 * If this class is in an unnamed module then the {@linkplain
1026 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1027 * loader for this class is returned.
1028 *
1029 * @return the module that this class or interface is a member of
1030 *
1031 * @since 9
1032 */
1033 public Module getModule() {
1034 return module;
1035 }
1036
1037 // set by VM
1038 @Stable
1039 private transient Module module;
1040
1041 // Initialized in JVM not by private constructor
1042 // This field is filtered from reflection access, i.e. getDeclaredField
1043 // will throw NoSuchFieldException
1044 private final ClassLoader classLoader;
1045
1046 private transient Object classData; // Set by VM
1047 private transient Object[] signers; // Read by VM, mutable
1048 private final transient char modifiers; // Set by the VM
1049 private final transient char classFileAccessFlags; // Set by the VM
1050 private final transient boolean primitive; // Set by the VM if the Class is a primitive type.
1051
1052 // package-private
1053 Object getClassData() {
1054 return classData;
1055 }
1056
1057 /**
1058 * Returns an array of {@code TypeVariable} objects that represent the
1059 * type variables declared by the generic declaration represented by this
1060 * {@code GenericDeclaration} object, in declaration order. Returns an
1061 * array of length 0 if the underlying generic declaration declares no type
1062 * variables.
1063 *
1064 * @return an array of {@code TypeVariable} objects that represent
1065 * the type variables declared by this generic declaration
1066 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1067 * signature of this generic declaration does not conform to
1068 * the format specified in section {@jvms 4.7.9} of
1069 * <cite>The Java Virtual Machine Specification</cite>
1070 * @since 1.5
1071 */
1072 @SuppressWarnings("unchecked")
1073 public TypeVariable<Class<T>>[] getTypeParameters() {
1074 ClassRepository info = getGenericInfo();
1075 if (info != null)
1076 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1077 else
1078 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1079 }
1080
1081
1082 /**
1083 * Returns the {@code Class} representing the direct superclass of the
1084 * entity (class, interface, primitive type or void) represented by
1085 * this {@code Class}. If this {@code Class} represents either the
1086 * {@code Object} class, an interface, a primitive type, or void, then
1087 * null is returned. If this {@code Class} object represents an array class
1088 * then the {@code Class} object representing the {@code Object} class is
1089 * returned.
1090 *
1091 * @return the direct superclass of the class represented by this {@code Class} object
1092 */
1093 @IntrinsicCandidate
1094 public native Class<? super T> getSuperclass();
1095
1096
1097 /**
1098 * Returns the {@code Type} representing the direct superclass of
1099 * the entity (class, interface, primitive type or void) represented by
1100 * this {@code Class} object.
1101 *
1102 * <p>If the superclass is a parameterized type, the {@code Type}
1103 * object returned must accurately reflect the actual type
1104 * arguments used in the source code. The parameterized type
1105 * representing the superclass is created if it had not been
1106 * created before. See the declaration of {@link
1107 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1108 * semantics of the creation process for parameterized types. If
1109 * this {@code Class} object represents either the {@code Object}
1110 * class, an interface, a primitive type, or void, then null is
1111 * returned. If this {@code Class} object represents an array class
1112 * then the {@code Class} object representing the {@code Object} class is
1113 * returned.
1114 *
1115 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1116 * class signature does not conform to the format specified in
1117 * section {@jvms 4.7.9} of <cite>The Java Virtual
1118 * Machine Specification</cite>
1119 * @throws TypeNotPresentException if the generic superclass
1120 * refers to a non-existent type declaration
1121 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1122 * generic superclass refers to a parameterized type that cannot be
1123 * instantiated for any reason
1124 * @return the direct superclass of the class represented by this {@code Class} object
1125 * @since 1.5
1126 */
1127 public Type getGenericSuperclass() {
1128 ClassRepository info = getGenericInfo();
1129 if (info == null) {
1130 return getSuperclass();
1131 }
1132
1133 // Historical irregularity:
1134 // Generic signature marks interfaces with superclass = Object
1135 // but this API returns null for interfaces
1136 if (isInterface()) {
1137 return null;
1138 }
1139
1140 return info.getSuperclass();
1141 }
1142
1143 /**
1144 * Gets the package of this class.
1145 *
1146 * <p>If this class represents an array type, a primitive type or void,
1147 * this method returns {@code null}.
1148 *
1149 * @return the package of this class.
1150 */
1151 public Package getPackage() {
1152 if (isPrimitive() || isArray()) {
1153 return null;
1154 }
1155 ClassLoader cl = classLoader;
1156 return cl != null ? cl.definePackage(this)
1157 : BootLoader.definePackage(this);
1158 }
1159
1160 /**
1161 * Returns the fully qualified package name.
1162 *
1163 * <p> If this class is a top level class, then this method returns the fully
1164 * qualified name of the package that the class is a member of, or the
1165 * empty string if the class is in an unnamed package.
1166 *
1167 * <p> If this class is a member class, then this method is equivalent to
1168 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1169 * enclosing class}.
1170 *
1171 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1172 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1173 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1174 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1175 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1176 *
1177 * <p> If this class represents an array type then this method returns the
1178 * package name of the element type. If this class represents a primitive
1179 * type or void then the package name "{@code java.lang}" is returned.
1180 *
1181 * @return the fully qualified package name
1182 *
1183 * @since 9
1184 * @jls 6.7 Fully Qualified Names and Canonical Names
1185 */
1186 public String getPackageName() {
1187 String pn = this.packageName;
1188 if (pn == null) {
1189 Class<?> c = isArray() ? elementType() : this;
1190 if (c.isPrimitive()) {
1191 pn = "java.lang";
1192 } else {
1193 String cn = c.getName();
1194 int dot = cn.lastIndexOf('.');
1195 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1196 }
1197 this.packageName = pn;
1198 }
1199 return pn;
1200 }
1201
1202 // cached package name
1203 private transient String packageName;
1204
1205 /**
1206 * Returns the interfaces directly implemented by the class or interface
1207 * represented by this {@code Class} object.
1208 *
1209 * <p>If this {@code Class} object represents a class, the return value is an array
1210 * containing objects representing all interfaces directly implemented by
1211 * the class. The order of the interface objects in the array corresponds
1212 * to the order of the interface names in the {@code implements} clause of
1213 * the declaration of the class represented by this {@code Class} object. For example,
1214 * given the declaration:
1215 * <blockquote>
1216 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1217 * </blockquote>
1218 * suppose the value of {@code s} is an instance of
1219 * {@code Shimmer}; the value of the expression:
1220 * <blockquote>
1221 * {@code s.getClass().getInterfaces()[0]}
1222 * </blockquote>
1223 * is the {@code Class} object that represents interface
1224 * {@code FloorWax}; and the value of:
1225 * <blockquote>
1226 * {@code s.getClass().getInterfaces()[1]}
1227 * </blockquote>
1228 * is the {@code Class} object that represents interface
1229 * {@code DessertTopping}.
1230 *
1231 * <p>If this {@code Class} object represents an interface, the array contains objects
1232 * representing all interfaces directly extended by the interface. The
1233 * order of the interface objects in the array corresponds to the order of
1234 * the interface names in the {@code extends} clause of the declaration of
1235 * the interface represented by this {@code Class} object.
1236 *
1237 * <p>If this {@code Class} object represents a class or interface that implements no
1238 * interfaces, the method returns an array of length 0.
1239 *
1240 * <p>If this {@code Class} object represents a primitive type or void, the method
1241 * returns an array of length 0.
1242 *
1243 * <p>If this {@code Class} object represents an array type, the
1244 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1245 * returned in that order.
1246 *
1247 * @return an array of interfaces directly implemented by this class
1248 */
1249 public Class<?>[] getInterfaces() {
1250 // defensively copy before handing over to user code
1251 return getInterfaces(true);
1252 }
1253
1254 private Class<?>[] getInterfaces(boolean cloneArray) {
1255 ReflectionData<T> rd = reflectionData();
1256 Class<?>[] interfaces = rd.interfaces;
1257 if (interfaces == null) {
1258 interfaces = getInterfaces0();
1259 rd.interfaces = interfaces;
1260 }
1261 // defensively copy if requested
1262 return cloneArray ? interfaces.clone() : interfaces;
1263 }
1264
1265 private native Class<?>[] getInterfaces0();
1266
1267 /**
1268 * Returns the {@code Type}s representing the interfaces
1269 * directly implemented by the class or interface represented by
1270 * this {@code Class} object.
1271 *
1272 * <p>If a superinterface is a parameterized type, the
1273 * {@code Type} object returned for it must accurately reflect
1274 * the actual type arguments used in the source code. The
1275 * parameterized type representing each superinterface is created
1276 * if it had not been created before. See the declaration of
1277 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1278 * for the semantics of the creation process for parameterized
1279 * types.
1280 *
1281 * <p>If this {@code Class} object represents a class, the return value is an array
1282 * containing objects representing all interfaces directly implemented by
1283 * the class. The order of the interface objects in the array corresponds
1284 * to the order of the interface names in the {@code implements} clause of
1285 * the declaration of the class represented by this {@code Class} object.
1286 *
1287 * <p>If this {@code Class} object represents an interface, the array contains objects
1288 * representing all interfaces directly extended by the interface. The
1289 * order of the interface objects in the array corresponds to the order of
1290 * the interface names in the {@code extends} clause of the declaration of
1291 * the interface represented by this {@code Class} object.
1292 *
1293 * <p>If this {@code Class} object represents a class or interface that implements no
1294 * interfaces, the method returns an array of length 0.
1295 *
1296 * <p>If this {@code Class} object represents a primitive type or void, the method
1297 * returns an array of length 0.
1298 *
1299 * <p>If this {@code Class} object represents an array type, the
1300 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1301 * returned in that order.
1302 *
1303 * @throws java.lang.reflect.GenericSignatureFormatError
1304 * if the generic class signature does not conform to the
1305 * format specified in section {@jvms 4.7.9} of <cite>The
1306 * Java Virtual Machine Specification</cite>
1307 * @throws TypeNotPresentException if any of the generic
1308 * superinterfaces refers to a non-existent type declaration
1309 * @throws java.lang.reflect.MalformedParameterizedTypeException
1310 * if any of the generic superinterfaces refer to a parameterized
1311 * type that cannot be instantiated for any reason
1312 * @return an array of interfaces directly implemented by this class
1313 * @since 1.5
1314 */
1315 public Type[] getGenericInterfaces() {
1316 ClassRepository info = getGenericInfo();
1317 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1318 }
1319
1320
1321 /**
1322 * Returns the {@code Class} representing the component type of an
1323 * array. If this class does not represent an array class this method
1324 * returns null.
1325 *
1326 * @return the {@code Class} representing the component type of this
1327 * class if this class is an array
1328 * @see java.lang.reflect.Array
1329 * @since 1.1
1330 */
1331 public Class<?> getComponentType() {
1332 return componentType;
1333 }
1334
1335 // The componentType field's null value is the sole indication that the class
1336 // is an array - see isArray().
1337 private transient final Class<?> componentType;
1338
1339 /*
1340 * Returns the {@code Class} representing the element type of an array class.
1341 * If this class does not represent an array class, then this method returns
1342 * {@code null}.
1343 */
1344 private Class<?> elementType() {
1345 if (!isArray()) return null;
1346
1347 Class<?> c = this;
1348 while (c.isArray()) {
1349 c = c.getComponentType();
1350 }
1351 return c;
1352 }
1353
1354 /**
1355 * Returns the Java language modifiers for this class or interface, encoded
1356 * in an integer. The modifiers consist of the Java Virtual Machine's
1357 * constants for {@code public}, {@code protected},
1358 * {@code private}, {@code final}, {@code static},
1359 * {@code abstract} and {@code interface}; they should be decoded
1360 * using the methods of class {@code Modifier}.
1361 *
1362 * <p> If the underlying class is an array class:
1363 * <ul>
1364 * <li> its {@code public}, {@code private} and {@code protected}
1365 * modifiers are the same as those of its component type
1366 * <li> its {@code abstract} and {@code final} modifiers are always
1367 * {@code true}
1368 * <li> its interface modifier is always {@code false}, even when
1369 * the component type is an interface
1370 * </ul>
1371 * If this {@code Class} object represents a primitive type or
1372 * void, its {@code public}, {@code abstract}, and {@code final}
1373 * modifiers are always {@code true}.
1374 * For {@code Class} objects representing void, primitive types, and
1375 * arrays, the values of other modifiers are {@code false} other
1376 * than as specified above.
1377 *
1378 * <p> The modifier encodings are defined in section {@jvms 4.1}
1379 * of <cite>The Java Virtual Machine Specification</cite>.
1380 *
1381 * @return the {@code int} representing the modifiers for this class
1382 * @see java.lang.reflect.Modifier
1383 * @see #accessFlags()
1384 * @see <a
1385 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1386 * programming language and JVM modeling in core reflection</a>
1387 * @since 1.1
1388 * @jls 8.1.1 Class Modifiers
1389 * @jls 9.1.1 Interface Modifiers
1390 * @jvms 4.1 The {@code ClassFile} Structure
1391 */
1392 public int getModifiers() { return modifiers; }
1393
1394 /**
1395 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1396 * flags} for this class, possibly empty}
1397 *
1398 * <p> If the underlying class is an array class:
1399 * <ul>
1400 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1401 * access flags are the same as those of its component type
1402 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1403 * <li> its {@code INTERFACE} flag is absent, even when the
1404 * component type is an interface
1405 * </ul>
1406 * If this {@code Class} object represents a primitive type or
1407 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1408 * {@code FINAL}.
1409 * For {@code Class} objects representing void, primitive types, and
1410 * arrays, access flags are absent other than as specified above.
1411 *
1412 * @see #getModifiers()
1413 * @jvms 4.1 The ClassFile Structure
1414 * @jvms 4.7.6 The InnerClasses Attribute
1415 * @since 20
1416 */
1417 public Set<AccessFlag> accessFlags() {
1418 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1419 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1420 // and STATIC, which are not allowed on Location.CLASS.
1421 // Use getClassFileAccessFlags to expose SUPER status.
1422 var location = (isMemberClass() || isLocalClass() ||
1423 isAnonymousClass() || isArray()) ?
1424 AccessFlag.Location.INNER_CLASS :
1425 AccessFlag.Location.CLASS;
1426 return getReflectionFactory().parseAccessFlags((location == AccessFlag.Location.CLASS) ?
1427 getClassFileAccessFlags() : getModifiers(), location, this);
1428 }
1429
1430 /**
1431 * Gets the signers of this class.
1432 *
1433 * @return the signers of this class, or null if there are no signers. In
1434 * particular, this method returns null if this {@code Class} object represents
1435 * a primitive type or void.
1436 * @since 1.1
1437 */
1438 public Object[] getSigners() {
1439 var signers = this.signers;
1440 return signers == null ? null : signers.clone();
1441 }
1442
1443 /**
1444 * Set the signers of this class.
1445 */
1446 void setSigners(Object[] signers) {
1447 if (!isPrimitive() && !isArray()) {
1448 this.signers = signers;
1449 }
1450 }
1451
1452 /**
1453 * If this {@code Class} object represents a local or anonymous
1454 * class within a method, returns a {@link
1455 * java.lang.reflect.Method Method} object representing the
1456 * immediately enclosing method of the underlying class. Returns
1457 * {@code null} otherwise.
1458 *
1459 * In particular, this method returns {@code null} if the underlying
1460 * class is a local or anonymous class immediately enclosed by a class or
1461 * interface declaration, instance initializer or static initializer.
1462 *
1463 * @return the immediately enclosing method of the underlying class, if
1464 * that class is a local or anonymous class; otherwise {@code null}.
1465 *
1466 * @since 1.5
1467 */
1468 public Method getEnclosingMethod() {
1469 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1470
1471 if (enclosingInfo == null)
1472 return null;
1473 else {
1474 if (!enclosingInfo.isMethod())
1475 return null;
1476
1477 // Descriptor already validated by VM
1478 List<Class<?>> types = BytecodeDescriptor.parseMethod(enclosingInfo.getDescriptor(), getClassLoader());
1479 Class<?> returnType = types.removeLast();
1480 Class<?>[] parameterClasses = types.toArray(EMPTY_CLASS_ARRAY);
1481
1482 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1483 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1484
1485 /*
1486 * Loop over all declared methods; match method name,
1487 * number of and type of parameters, *and* return
1488 * type. Matching return type is also necessary
1489 * because of covariant returns, etc.
1490 */
1491 ReflectionFactory fact = getReflectionFactory();
1492 for (Method m : candidates) {
1493 if (m.getName().equals(enclosingInfo.getName()) &&
1494 arrayContentsEq(parameterClasses,
1495 fact.getExecutableSharedParameterTypes(m))) {
1496 // finally, check return type
1497 if (m.getReturnType().equals(returnType)) {
1498 return fact.copyMethod(m);
1499 }
1500 }
1501 }
1502
1503 throw new InternalError("Enclosing method not found");
1504 }
1505 }
1506
1507 private native Object[] getEnclosingMethod0();
1508
1509 private EnclosingMethodInfo getEnclosingMethodInfo() {
1510 Object[] enclosingInfo = getEnclosingMethod0();
1511 if (enclosingInfo == null)
1512 return null;
1513 else {
1514 return new EnclosingMethodInfo(enclosingInfo);
1515 }
1516 }
1517
1518 private static final class EnclosingMethodInfo {
1519 private final Class<?> enclosingClass;
1520 private final String name;
1521 private final String descriptor;
1522
1523 static void validate(Object[] enclosingInfo) {
1524 if (enclosingInfo.length != 3)
1525 throw new InternalError("Malformed enclosing method information");
1526 try {
1527 // The array is expected to have three elements:
1528
1529 // the immediately enclosing class
1530 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1531 assert(enclosingClass != null);
1532
1533 // the immediately enclosing method or constructor's
1534 // name (can be null).
1535 String name = (String)enclosingInfo[1];
1536
1537 // the immediately enclosing method or constructor's
1538 // descriptor (null iff name is).
1539 String descriptor = (String)enclosingInfo[2];
1540 assert((name != null && descriptor != null) || name == descriptor);
1541 } catch (ClassCastException cce) {
1542 throw new InternalError("Invalid type in enclosing method information", cce);
1543 }
1544 }
1545
1546 EnclosingMethodInfo(Object[] enclosingInfo) {
1547 validate(enclosingInfo);
1548 this.enclosingClass = (Class<?>)enclosingInfo[0];
1549 this.name = (String)enclosingInfo[1];
1550 this.descriptor = (String)enclosingInfo[2];
1551 }
1552
1553 boolean isPartial() {
1554 return enclosingClass == null || name == null || descriptor == null;
1555 }
1556
1557 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1558
1559 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1560
1561 Class<?> getEnclosingClass() { return enclosingClass; }
1562
1563 String getName() { return name; }
1564
1565 String getDescriptor() { return descriptor; }
1566
1567 }
1568
1569 private static Class<?> toClass(Type o) {
1570 if (o instanceof GenericArrayType gat)
1571 return toClass(gat.getGenericComponentType()).arrayType();
1572 return (Class<?>)o;
1573 }
1574
1575 /**
1576 * If this {@code Class} object represents a local or anonymous
1577 * class within a constructor, returns a {@link
1578 * java.lang.reflect.Constructor Constructor} object representing
1579 * the immediately enclosing constructor of the underlying
1580 * class. Returns {@code null} otherwise. In particular, this
1581 * method returns {@code null} if the underlying class is a local
1582 * or anonymous class immediately enclosed by a class or
1583 * interface declaration, instance initializer or static initializer.
1584 *
1585 * @return the immediately enclosing constructor of the underlying class, if
1586 * that class is a local or anonymous class; otherwise {@code null}.
1587 *
1588 * @since 1.5
1589 */
1590 public Constructor<?> getEnclosingConstructor() {
1591 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1592
1593 if (enclosingInfo == null)
1594 return null;
1595 else {
1596 if (!enclosingInfo.isConstructor())
1597 return null;
1598
1599 // Descriptor already validated by VM
1600 List<Class<?>> types = BytecodeDescriptor.parseMethod(enclosingInfo.getDescriptor(), getClassLoader());
1601 types.removeLast();
1602 Class<?>[] parameterClasses = types.toArray(EMPTY_CLASS_ARRAY);
1603
1604 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1605 Constructor<?>[] candidates = enclosingCandidate
1606 .privateGetDeclaredConstructors(false);
1607 /*
1608 * Loop over all declared constructors; match number
1609 * of and type of parameters.
1610 */
1611 ReflectionFactory fact = getReflectionFactory();
1612 for (Constructor<?> c : candidates) {
1613 if (arrayContentsEq(parameterClasses,
1614 fact.getExecutableSharedParameterTypes(c))) {
1615 return fact.copyConstructor(c);
1616 }
1617 }
1618
1619 throw new InternalError("Enclosing constructor not found");
1620 }
1621 }
1622
1623
1624 /**
1625 * If the class or interface represented by this {@code Class} object
1626 * is a member of another class, returns the {@code Class} object
1627 * representing the class in which it was declared. This method returns
1628 * null if this class or interface is not a member of any other class. If
1629 * this {@code Class} object represents an array class, a primitive
1630 * type, or void, then this method returns null.
1631 *
1632 * @return the declaring class for this class
1633 * @since 1.1
1634 */
1635 public Class<?> getDeclaringClass() {
1636 return getDeclaringClass0();
1637 }
1638
1639 private native Class<?> getDeclaringClass0();
1640
1641
1642 /**
1643 * Returns the immediately enclosing class of the underlying
1644 * class. If the underlying class is a top level class this
1645 * method returns {@code null}.
1646 * @return the immediately enclosing class of the underlying class
1647 * @since 1.5
1648 */
1649 public Class<?> getEnclosingClass() {
1650 // There are five kinds of classes (or interfaces):
1651 // a) Top level classes
1652 // b) Nested classes (static member classes)
1653 // c) Inner classes (non-static member classes)
1654 // d) Local classes (named classes declared within a method)
1655 // e) Anonymous classes
1656
1657
1658 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1659 // attribute if and only if it is a local class or an
1660 // anonymous class.
1661 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1662 Class<?> enclosingCandidate;
1663
1664 if (enclosingInfo == null) {
1665 // This is a top level or a nested class or an inner class (a, b, or c)
1666 enclosingCandidate = getDeclaringClass0();
1667 } else {
1668 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1669 // This is a local class or an anonymous class (d or e)
1670 if (enclosingClass == this || enclosingClass == null)
1671 throw new InternalError("Malformed enclosing method information");
1672 else
1673 enclosingCandidate = enclosingClass;
1674 }
1675 return enclosingCandidate;
1676 }
1677
1678 /**
1679 * Returns the simple name of the underlying class as given in the
1680 * source code. An empty string is returned if the underlying class is
1681 * {@linkplain #isAnonymousClass() anonymous}.
1682 * A {@linkplain #isSynthetic() synthetic class}, one not present
1683 * in source code, can have a non-empty name including special
1684 * characters, such as "{@code $}".
1685 *
1686 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1687 * component type with "[]" appended. In particular the simple
1688 * name of an array class whose component type is anonymous is "[]".
1689 *
1690 * @return the simple name of the underlying class
1691 * @since 1.5
1692 */
1693 public String getSimpleName() {
1694 ReflectionData<T> rd = reflectionData();
1695 String simpleName = rd.simpleName;
1696 if (simpleName == null) {
1697 rd.simpleName = simpleName = getSimpleName0();
1698 }
1699 return simpleName;
1700 }
1701
1702 private String getSimpleName0() {
1703 if (isArray()) {
1704 return getComponentType().getSimpleName().concat("[]");
1705 }
1706 String simpleName = getSimpleBinaryName();
1707 if (simpleName == null) { // top level class
1708 simpleName = getName();
1709 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1710 }
1711 return simpleName;
1712 }
1713
1714 /**
1715 * Return an informative string for the name of this class or interface.
1716 *
1717 * @return an informative string for the name of this class or interface
1718 * @since 1.8
1719 */
1720 public String getTypeName() {
1721 if (isArray()) {
1722 try {
1723 Class<?> cl = this;
1724 int dimensions = 0;
1725 do {
1726 dimensions++;
1727 cl = cl.getComponentType();
1728 } while (cl.isArray());
1729 return cl.getName().concat("[]".repeat(dimensions));
1730 } catch (Throwable e) { /*FALLTHRU*/ }
1731 }
1732 return getName();
1733 }
1734
1735 /**
1736 * Returns the canonical name of the underlying class as
1737 * defined by <cite>The Java Language Specification</cite>.
1738 * Returns {@code null} if the underlying class does not have a canonical
1739 * name. Classes without canonical names include:
1740 * <ul>
1741 * <li>a {@linkplain #isLocalClass() local class}
1742 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1743 * <li>a {@linkplain #isHidden() hidden class}
1744 * <li>an array whose component type does not have a canonical name</li>
1745 * </ul>
1746 *
1747 * The canonical name for a primitive class is the keyword for the
1748 * corresponding primitive type ({@code byte}, {@code short},
1749 * {@code char}, {@code int}, and so on).
1750 *
1751 * <p>An array type has a canonical name if and only if its
1752 * component type has a canonical name. When an array type has a
1753 * canonical name, it is equal to the canonical name of the
1754 * component type followed by "{@code []}".
1755 *
1756 * @return the canonical name of the underlying class if it exists, and
1757 * {@code null} otherwise.
1758 * @jls 6.7 Fully Qualified Names and Canonical Names
1759 * @since 1.5
1760 */
1761 public String getCanonicalName() {
1762 ReflectionData<T> rd = reflectionData();
1763 String canonicalName = rd.canonicalName;
1764 if (canonicalName == null) {
1765 rd.canonicalName = canonicalName = getCanonicalName0();
1766 }
1767 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1768 }
1769
1770 private String getCanonicalName0() {
1771 if (isArray()) {
1772 String canonicalName = getComponentType().getCanonicalName();
1773 if (canonicalName != null)
1774 return canonicalName.concat("[]");
1775 else
1776 return ReflectionData.NULL_SENTINEL;
1777 }
1778 if (isHidden() || isLocalOrAnonymousClass())
1779 return ReflectionData.NULL_SENTINEL;
1780 Class<?> enclosingClass = getEnclosingClass();
1781 if (enclosingClass == null) { // top level class
1782 return getName();
1783 } else {
1784 String enclosingName = enclosingClass.getCanonicalName();
1785 if (enclosingName == null)
1786 return ReflectionData.NULL_SENTINEL;
1787 String simpleName = getSimpleName();
1788 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1789 .append(enclosingName)
1790 .append('.')
1791 .append(simpleName)
1792 .toString();
1793 }
1794 }
1795
1796 /**
1797 * Returns {@code true} if and only if the underlying class
1798 * is an anonymous class.
1799 *
1800 * @apiNote
1801 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1802 *
1803 * @return {@code true} if and only if this class is an anonymous class.
1804 * @since 1.5
1805 * @jls 15.9.5 Anonymous Class Declarations
1806 */
1807 public boolean isAnonymousClass() {
1808 return !isArray() && isLocalOrAnonymousClass() &&
1809 getSimpleBinaryName0() == null;
1810 }
1811
1812 /**
1813 * Returns {@code true} if and only if the underlying class
1814 * is a local class.
1815 *
1816 * @return {@code true} if and only if this class is a local class.
1817 * @since 1.5
1818 * @jls 14.3 Local Class and Interface Declarations
1819 */
1820 public boolean isLocalClass() {
1821 return isLocalOrAnonymousClass() &&
1822 (isArray() || getSimpleBinaryName0() != null);
1823 }
1824
1825 /**
1826 * Returns {@code true} if and only if the underlying class
1827 * is a member class.
1828 *
1829 * @return {@code true} if and only if this class is a member class.
1830 * @since 1.5
1831 * @jls 8.5 Member Class and Interface Declarations
1832 */
1833 public boolean isMemberClass() {
1834 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1835 }
1836
1837 /**
1838 * Returns the "simple binary name" of the underlying class, i.e.,
1839 * the binary name without the leading enclosing class name.
1840 * Returns {@code null} if the underlying class is a top level
1841 * class.
1842 */
1843 private String getSimpleBinaryName() {
1844 if (isTopLevelClass())
1845 return null;
1846 String name = getSimpleBinaryName0();
1847 if (name == null) // anonymous class
1848 return "";
1849 return name;
1850 }
1851
1852 private native String getSimpleBinaryName0();
1853
1854 /**
1855 * Returns {@code true} if this is a top level class. Returns {@code false}
1856 * otherwise.
1857 */
1858 private boolean isTopLevelClass() {
1859 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1860 }
1861
1862 /**
1863 * Returns {@code true} if this is a local class or an anonymous
1864 * class. Returns {@code false} otherwise.
1865 */
1866 private boolean isLocalOrAnonymousClass() {
1867 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1868 // attribute if and only if it is a local class or an
1869 // anonymous class.
1870 return hasEnclosingMethodInfo();
1871 }
1872
1873 private boolean hasEnclosingMethodInfo() {
1874 Object[] enclosingInfo = getEnclosingMethod0();
1875 if (enclosingInfo != null) {
1876 EnclosingMethodInfo.validate(enclosingInfo);
1877 return true;
1878 }
1879 return false;
1880 }
1881
1882 /**
1883 * Returns an array containing {@code Class} objects representing all
1884 * the public classes and interfaces that are members of the class
1885 * represented by this {@code Class} object. This includes public
1886 * class and interface members inherited from superclasses and public class
1887 * and interface members declared by the class. This method returns an
1888 * array of length 0 if this {@code Class} object has no public member
1889 * classes or interfaces. This method also returns an array of length 0 if
1890 * this {@code Class} object represents a primitive type, an array
1891 * class, or void.
1892 *
1893 * @return the array of {@code Class} objects representing the public
1894 * members of this class
1895 * @since 1.1
1896 */
1897 public Class<?>[] getClasses() {
1898 List<Class<?>> list = new ArrayList<>();
1899 Class<?> currentClass = Class.this;
1900 while (currentClass != null) {
1901 for (Class<?> m : currentClass.getDeclaredClasses()) {
1902 if (Modifier.isPublic(m.getModifiers())) {
1903 list.add(m);
1904 }
1905 }
1906 currentClass = currentClass.getSuperclass();
1907 }
1908 return list.toArray(EMPTY_CLASS_ARRAY);
1909 }
1910
1911
1912 /**
1913 * Returns an array containing {@code Field} objects reflecting all
1914 * the accessible public fields of the class or interface represented by
1915 * this {@code Class} object.
1916 *
1917 * <p> If this {@code Class} object represents a class or interface with
1918 * no accessible public fields, then this method returns an array of length
1919 * 0.
1920 *
1921 * <p> If this {@code Class} object represents a class, then this method
1922 * returns the public fields of the class and of all its superclasses and
1923 * superinterfaces.
1924 *
1925 * <p> If this {@code Class} object represents an interface, then this
1926 * method returns the fields of the interface and of all its
1927 * superinterfaces.
1928 *
1929 * <p> If this {@code Class} object represents an array type, a primitive
1930 * type, or void, then this method returns an array of length 0.
1931 *
1932 * <p> The elements in the returned array are not sorted and are not in any
1933 * particular order.
1934 *
1935 * @return the array of {@code Field} objects representing the
1936 * public fields
1937 *
1938 * @since 1.1
1939 * @jls 8.2 Class Members
1940 * @jls 8.3 Field Declarations
1941 */
1942 public Field[] getFields() {
1943 return copyFields(privateGetPublicFields());
1944 }
1945
1946
1947 /**
1948 * Returns an array containing {@code Method} objects reflecting all the
1949 * public methods of the class or interface represented by this {@code
1950 * Class} object, including those declared by the class or interface and
1951 * those inherited from superclasses and superinterfaces.
1952 *
1953 * <p> If this {@code Class} object represents an array type, then the
1954 * returned array has a {@code Method} object for each of the public
1955 * methods inherited by the array type from {@code Object}. It does not
1956 * contain a {@code Method} object for {@code clone()}.
1957 *
1958 * <p> If this {@code Class} object represents an interface then the
1959 * returned array does not contain any implicitly declared methods from
1960 * {@code Object}. Therefore, if no methods are explicitly declared in
1961 * this interface or any of its superinterfaces then the returned array
1962 * has length 0. (Note that a {@code Class} object which represents a class
1963 * always has public methods, inherited from {@code Object}.)
1964 *
1965 * <p> The returned array never contains methods with names {@value
1966 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1967 *
1968 * <p> The elements in the returned array are not sorted and are not in any
1969 * particular order.
1970 *
1971 * <p> Generally, the result is computed as with the following 4 step algorithm.
1972 * Let C be the class or interface represented by this {@code Class} object:
1973 * <ol>
1974 * <li> A union of methods is composed of:
1975 * <ol type="a">
1976 * <li> C's declared public instance and static methods as returned by
1977 * {@link #getDeclaredMethods()} and filtered to include only public
1978 * methods.</li>
1979 * <li> If C is a class other than {@code Object}, then include the result
1980 * of invoking this algorithm recursively on the superclass of C.</li>
1981 * <li> Include the results of invoking this algorithm recursively on all
1982 * direct superinterfaces of C, but include only instance methods.</li>
1983 * </ol></li>
1984 * <li> Union from step 1 is partitioned into subsets of methods with same
1985 * signature (name, parameter types) and return type.</li>
1986 * <li> Within each such subset only the most specific methods are selected.
1987 * Let method M be a method from a set of methods with same signature
1988 * and return type. M is most specific if there is no such method
1989 * N != M from the same set, such that N is more specific than M.
1990 * N is more specific than M if:
1991 * <ol type="a">
1992 * <li> N is declared by a class and M is declared by an interface; or</li>
1993 * <li> N and M are both declared by classes or both by interfaces and
1994 * N's declaring type is the same as or a subtype of M's declaring type
1995 * (clearly, if M's and N's declaring types are the same type, then
1996 * M and N are the same method).</li>
1997 * </ol></li>
1998 * <li> The result of this algorithm is the union of all selected methods from
1999 * step 3.</li>
2000 * </ol>
2001 *
2002 * @apiNote There may be more than one method with a particular name
2003 * and parameter types in a class because while the Java language forbids a
2004 * class to declare multiple methods with the same signature but different
2005 * return types, the Java virtual machine does not. This
2006 * increased flexibility in the virtual machine can be used to
2007 * implement various language features. For example, covariant
2008 * returns can be implemented with {@linkplain
2009 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2010 * method and the overriding method would have the same
2011 * signature but different return types.
2012 *
2013 * @return the array of {@code Method} objects representing the
2014 * public methods of this class
2015 *
2016 * @jls 8.2 Class Members
2017 * @jls 8.4 Method Declarations
2018 * @since 1.1
2019 */
2020 public Method[] getMethods() {
2021 return copyMethods(privateGetPublicMethods());
2022 }
2023
2024
2025 /**
2026 * Returns an array containing {@code Constructor} objects reflecting
2027 * all the public constructors of the class represented by this
2028 * {@code Class} object. An array of length 0 is returned if the
2029 * class has no public constructors, or if the class is an array class, or
2030 * if the class reflects a primitive type or void.
2031 *
2032 * @apiNote
2033 * While this method returns an array of {@code
2034 * Constructor<T>} objects (that is an array of constructors from
2035 * this class), the return type of this method is {@code
2036 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2037 * might be expected. This less informative return type is
2038 * necessary since after being returned from this method, the
2039 * array could be modified to hold {@code Constructor} objects for
2040 * different classes, which would violate the type guarantees of
2041 * {@code Constructor<T>[]}.
2042 *
2043 * @return the array of {@code Constructor} objects representing the
2044 * public constructors of this class
2045 *
2046 * @see #getDeclaredConstructors()
2047 * @since 1.1
2048 */
2049 public Constructor<?>[] getConstructors() {
2050 return copyConstructors(privateGetDeclaredConstructors(true));
2051 }
2052
2053
2054 /**
2055 * Returns a {@code Field} object that reflects the specified public member
2056 * field of the class or interface represented by this {@code Class}
2057 * object. The {@code name} parameter is a {@code String} specifying the
2058 * simple name of the desired field.
2059 *
2060 * <p> The field to be reflected is determined by the algorithm that
2061 * follows. Let C be the class or interface represented by this {@code Class} object:
2062 *
2063 * <OL>
2064 * <LI> If C declares a public field with the name specified, that is the
2065 * field to be reflected.</LI>
2066 * <LI> If no field was found in step 1 above, this algorithm is applied
2067 * recursively to each direct superinterface of C. The direct
2068 * superinterfaces are searched in the order they were declared.</LI>
2069 * <LI> If no field was found in steps 1 and 2 above, and C has a
2070 * superclass S, then this algorithm is invoked recursively upon S.
2071 * If C has no superclass, then a {@code NoSuchFieldException}
2072 * is thrown.</LI>
2073 * </OL>
2074 *
2075 * <p> If this {@code Class} object represents an array type, then this
2076 * method does not find the {@code length} field of the array type.
2077 *
2078 * @param name the field name
2079 * @return the {@code Field} object of this class specified by
2080 * {@code name}
2081 * @throws NoSuchFieldException if a field with the specified name is
2082 * not found.
2083 * @throws NullPointerException if {@code name} is {@code null}
2084 *
2085 * @since 1.1
2086 * @jls 8.2 Class Members
2087 * @jls 8.3 Field Declarations
2088 */
2089 public Field getField(String name) throws NoSuchFieldException {
2090 Objects.requireNonNull(name);
2091 Field field = getField0(name);
2092 if (field == null) {
2093 throw new NoSuchFieldException(name);
2094 }
2095 return getReflectionFactory().copyField(field);
2096 }
2097
2098
2099 /**
2100 * Returns a {@code Method} object that reflects the specified public
2101 * member method of the class or interface represented by this
2102 * {@code Class} object. The {@code name} parameter is a
2103 * {@code String} specifying the simple name of the desired method. The
2104 * {@code parameterTypes} parameter is an array of {@code Class}
2105 * objects that identify the method's formal parameter types, in declared
2106 * order. If {@code parameterTypes} is {@code null}, it is
2107 * treated as if it were an empty array.
2108 *
2109 * <p> If this {@code Class} object represents an array type, then this
2110 * method finds any public method inherited by the array type from
2111 * {@code Object} except method {@code clone()}.
2112 *
2113 * <p> If this {@code Class} object represents an interface then this
2114 * method does not find any implicitly declared method from
2115 * {@code Object}. Therefore, if no methods are explicitly declared in
2116 * this interface or any of its superinterfaces, then this method does not
2117 * find any method.
2118 *
2119 * <p> This method does not find any method with name {@value
2120 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2121 *
2122 * <p> Generally, the method to be reflected is determined by the 4 step
2123 * algorithm that follows.
2124 * Let C be the class or interface represented by this {@code Class} object:
2125 * <ol>
2126 * <li> A union of methods is composed of:
2127 * <ol type="a">
2128 * <li> C's declared public instance and static methods as returned by
2129 * {@link #getDeclaredMethods()} and filtered to include only public
2130 * methods that match given {@code name} and {@code parameterTypes}</li>
2131 * <li> If C is a class other than {@code Object}, then include the result
2132 * of invoking this algorithm recursively on the superclass of C.</li>
2133 * <li> Include the results of invoking this algorithm recursively on all
2134 * direct superinterfaces of C, but include only instance methods.</li>
2135 * </ol></li>
2136 * <li> This union is partitioned into subsets of methods with same
2137 * return type (the selection of methods from step 1 also guarantees that
2138 * they have the same method name and parameter types).</li>
2139 * <li> Within each such subset only the most specific methods are selected.
2140 * Let method M be a method from a set of methods with same VM
2141 * signature (return type, name, parameter types).
2142 * M is most specific if there is no such method N != M from the same
2143 * set, such that N is more specific than M. N is more specific than M
2144 * if:
2145 * <ol type="a">
2146 * <li> N is declared by a class and M is declared by an interface; or</li>
2147 * <li> N and M are both declared by classes or both by interfaces and
2148 * N's declaring type is the same as or a subtype of M's declaring type
2149 * (clearly, if M's and N's declaring types are the same type, then
2150 * M and N are the same method).</li>
2151 * </ol></li>
2152 * <li> The result of this algorithm is chosen arbitrarily from the methods
2153 * with most specific return type among all selected methods from step 3.
2154 * Let R be a return type of a method M from the set of all selected methods
2155 * from step 3. M is a method with most specific return type if there is
2156 * no such method N != M from the same set, having return type S != R,
2157 * such that S is a subtype of R as determined by
2158 * R.class.{@link #isAssignableFrom}(S.class).
2159 * </ol>
2160 *
2161 * @apiNote There may be more than one method with matching name and
2162 * parameter types in a class because while the Java language forbids a
2163 * class to declare multiple methods with the same signature but different
2164 * return types, the Java virtual machine does not. This
2165 * increased flexibility in the virtual machine can be used to
2166 * implement various language features. For example, covariant
2167 * returns can be implemented with {@linkplain
2168 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2169 * method and the overriding method would have the same
2170 * signature but different return types. This method would return the
2171 * overriding method as it would have a more specific return type.
2172 *
2173 * @param name the name of the method
2174 * @param parameterTypes the list of parameters
2175 * @return the {@code Method} object that matches the specified
2176 * {@code name} and {@code parameterTypes}
2177 * @throws NoSuchMethodException if a matching method is not found
2178 * or if the name is {@value ConstantDescs#INIT_NAME} or
2179 * {@value ConstantDescs#CLASS_INIT_NAME}.
2180 * @throws NullPointerException if {@code name} is {@code null}
2181 *
2182 * @jls 8.2 Class Members
2183 * @jls 8.4 Method Declarations
2184 * @since 1.1
2185 */
2186 public Method getMethod(String name, Class<?>... parameterTypes)
2187 throws NoSuchMethodException {
2188 Objects.requireNonNull(name);
2189 Method method = getMethod0(name, parameterTypes);
2190 if (method == null) {
2191 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2192 }
2193 return getReflectionFactory().copyMethod(method);
2194 }
2195
2196 /**
2197 * Returns a {@code Constructor} object that reflects the specified
2198 * public constructor of the class represented by this {@code Class}
2199 * object. The {@code parameterTypes} parameter is an array of
2200 * {@code Class} objects that identify the constructor's formal
2201 * parameter types, in declared order.
2202 *
2203 * If this {@code Class} object represents an inner class
2204 * declared in a non-static context, the formal parameter types
2205 * include the explicit enclosing instance as the first parameter.
2206 *
2207 * <p> The constructor to reflect is the public constructor of the class
2208 * represented by this {@code Class} object whose formal parameter
2209 * types match those specified by {@code parameterTypes}.
2210 *
2211 * @param parameterTypes the parameter array
2212 * @return the {@code Constructor} object of the public constructor that
2213 * matches the specified {@code parameterTypes}
2214 * @throws NoSuchMethodException if a matching constructor is not found,
2215 * including when this {@code Class} object represents
2216 * an interface, a primitive type, an array class, or void.
2217 *
2218 * @see #getDeclaredConstructor(Class[])
2219 * @since 1.1
2220 */
2221 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2222 throws NoSuchMethodException {
2223 return getReflectionFactory().copyConstructor(
2224 getConstructor0(parameterTypes, Member.PUBLIC));
2225 }
2226
2227
2228 /**
2229 * Returns an array of {@code Class} objects reflecting all the
2230 * classes and interfaces declared as members of the class represented by
2231 * this {@code Class} object. This includes public, protected, default
2232 * (package) access, and private classes and interfaces declared by the
2233 * class, but excludes inherited classes and interfaces. This method
2234 * returns an array of length 0 if the class declares no classes or
2235 * interfaces as members, or if this {@code Class} object represents a
2236 * primitive type, an array class, or void.
2237 *
2238 * @return the array of {@code Class} objects representing all the
2239 * declared members of this class
2240 *
2241 * @since 1.1
2242 * @jls 8.5 Member Class and Interface Declarations
2243 */
2244 public Class<?>[] getDeclaredClasses() {
2245 return getDeclaredClasses0();
2246 }
2247
2248
2249 /**
2250 * Returns an array of {@code Field} objects reflecting all the fields
2251 * declared by the class or interface represented by this
2252 * {@code Class} object. This includes public, protected, default
2253 * (package) access, and private fields, but excludes inherited fields.
2254 *
2255 * <p> If this {@code Class} object represents a class or interface with no
2256 * declared fields, then this method returns an array of length 0.
2257 *
2258 * <p> If this {@code Class} object represents an array type, a primitive
2259 * type, or void, then this method returns an array of length 0.
2260 *
2261 * <p> The elements in the returned array are not sorted and are not in any
2262 * particular order.
2263 *
2264 * @return the array of {@code Field} objects representing all the
2265 * declared fields of this class
2266 *
2267 * @since 1.1
2268 * @jls 8.2 Class Members
2269 * @jls 8.3 Field Declarations
2270 */
2271 public Field[] getDeclaredFields() {
2272 return copyFields(privateGetDeclaredFields(false));
2273 }
2274
2275 /**
2276 * Returns an array of {@code RecordComponent} objects representing all the
2277 * record components of this record class, or {@code null} if this class is
2278 * not a record class.
2279 *
2280 * <p> The components are returned in the same order that they are declared
2281 * in the record header. The array is empty if this record class has no
2282 * components. If the class is not a record class, that is {@link
2283 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2284 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2285 * returns a non-null value.
2286 *
2287 * @apiNote
2288 * <p> The following method can be used to find the record canonical constructor:
2289 *
2290 * {@snippet lang="java" :
2291 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2292 * throws NoSuchMethodException {
2293 * Class<?>[] paramTypes =
2294 * Arrays.stream(cls.getRecordComponents())
2295 * .map(RecordComponent::getType)
2296 * .toArray(Class<?>[]::new);
2297 * return cls.getDeclaredConstructor(paramTypes);
2298 * }}
2299 *
2300 * @return An array of {@code RecordComponent} objects representing all the
2301 * record components of this record class, or {@code null} if this
2302 * class is not a record class
2303 *
2304 * @jls 8.10 Record Classes
2305 * @since 16
2306 */
2307 public RecordComponent[] getRecordComponents() {
2308 if (!isRecord()) {
2309 return null;
2310 }
2311 return getRecordComponents0();
2312 }
2313
2314 /**
2315 * Returns an array containing {@code Method} objects reflecting all the
2316 * declared methods of the class or interface represented by this {@code
2317 * Class} object, including public, protected, default (package)
2318 * access, and private methods, but excluding inherited methods.
2319 * The declared methods may include methods <em>not</em> in the
2320 * source of the class or interface, including {@linkplain
2321 * Method#isBridge bridge methods} and other {@linkplain
2322 * Executable#isSynthetic synthetic} methods added by compilers.
2323 *
2324 * <p> If this {@code Class} object represents a class or interface that
2325 * has multiple declared methods with the same name and parameter types,
2326 * but different return types, then the returned array has a {@code Method}
2327 * object for each such method.
2328 *
2329 * <p> If this {@code Class} object represents a class or interface that
2330 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2331 * then the returned array does <em>not</em> have a corresponding {@code
2332 * Method} object.
2333 *
2334 * <p> If this {@code Class} object represents a class or interface with no
2335 * declared methods, then the returned array has length 0.
2336 *
2337 * <p> If this {@code Class} object represents an array type, a primitive
2338 * type, or void, then the returned array has length 0.
2339 *
2340 * <p> The elements in the returned array are not sorted and are not in any
2341 * particular order.
2342 *
2343 * @return the array of {@code Method} objects representing all the
2344 * declared methods of this class
2345 *
2346 * @jls 8.2 Class Members
2347 * @jls 8.4 Method Declarations
2348 * @see <a
2349 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2350 * programming language and JVM modeling in core reflection</a>
2351 * @since 1.1
2352 */
2353 public Method[] getDeclaredMethods() {
2354 return copyMethods(privateGetDeclaredMethods(false));
2355 }
2356
2357 /**
2358 * Returns an array of {@code Constructor} objects reflecting all the
2359 * constructors implicitly or explicitly declared by the class represented by this
2360 * {@code Class} object. These are public, protected, default
2361 * (package) access, and private constructors. The elements in the array
2362 * returned are not sorted and are not in any particular order. If the
2363 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2364 * If a record class has a canonical constructor (JLS {@jls
2365 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2366 *
2367 * This method returns an array of length 0 if this {@code Class}
2368 * object represents an interface, a primitive type, an array class, or
2369 * void.
2370 *
2371 * @return the array of {@code Constructor} objects representing all the
2372 * declared constructors of this class
2373 *
2374 * @since 1.1
2375 * @see #getConstructors()
2376 * @jls 8.8 Constructor Declarations
2377 */
2378 public Constructor<?>[] getDeclaredConstructors() {
2379 return copyConstructors(privateGetDeclaredConstructors(false));
2380 }
2381
2382
2383 /**
2384 * Returns a {@code Field} object that reflects the specified declared
2385 * field of the class or interface represented by this {@code Class}
2386 * object. The {@code name} parameter is a {@code String} that specifies
2387 * the simple name of the desired field.
2388 *
2389 * <p> If this {@code Class} object represents an array type, then this
2390 * method does not find the {@code length} field of the array type.
2391 *
2392 * @param name the name of the field
2393 * @return the {@code Field} object for the specified field in this
2394 * class
2395 * @throws NoSuchFieldException if a field with the specified name is
2396 * not found.
2397 * @throws NullPointerException if {@code name} is {@code null}
2398 *
2399 * @since 1.1
2400 * @jls 8.2 Class Members
2401 * @jls 8.3 Field Declarations
2402 */
2403 public Field getDeclaredField(String name) throws NoSuchFieldException {
2404 Objects.requireNonNull(name);
2405 Field field = searchFields(privateGetDeclaredFields(false), name);
2406 if (field == null) {
2407 throw new NoSuchFieldException(name);
2408 }
2409 return getReflectionFactory().copyField(field);
2410 }
2411
2412
2413 /**
2414 * Returns a {@code Method} object that reflects the specified
2415 * declared method of the class or interface represented by this
2416 * {@code Class} object. The {@code name} parameter is a
2417 * {@code String} that specifies the simple name of the desired
2418 * method, and the {@code parameterTypes} parameter is an array of
2419 * {@code Class} objects that identify the method's formal parameter
2420 * types, in declared order. If more than one method with the same
2421 * parameter types is declared in a class, and one of these methods has a
2422 * return type that is more specific than any of the others, that method is
2423 * returned; otherwise one of the methods is chosen arbitrarily. If the
2424 * name is {@value ConstantDescs#INIT_NAME} or {@value
2425 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2426 * is raised.
2427 *
2428 * <p> If this {@code Class} object represents an array type, then this
2429 * method does not find the {@code clone()} method.
2430 *
2431 * @param name the name of the method
2432 * @param parameterTypes the parameter array
2433 * @return the {@code Method} object for the method of this class
2434 * matching the specified name and parameters
2435 * @throws NoSuchMethodException if a matching method is not found.
2436 * @throws NullPointerException if {@code name} is {@code null}
2437 *
2438 * @jls 8.2 Class Members
2439 * @jls 8.4 Method Declarations
2440 * @since 1.1
2441 */
2442 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2443 throws NoSuchMethodException {
2444 Objects.requireNonNull(name);
2445 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2446 if (method == null) {
2447 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2448 }
2449 return getReflectionFactory().copyMethod(method);
2450 }
2451
2452 /**
2453 * Returns the list of {@code Method} objects for the declared public
2454 * methods of this class or interface that have the specified method name
2455 * and parameter types.
2456 *
2457 * @param name the name of the method
2458 * @param parameterTypes the parameter array
2459 * @return the list of {@code Method} objects for the public methods of
2460 * this class matching the specified name and parameters
2461 */
2462 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2463 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2464 ReflectionFactory factory = getReflectionFactory();
2465 List<Method> result = new ArrayList<>();
2466 for (Method method : methods) {
2467 if (method.getName().equals(name)
2468 && Arrays.equals(
2469 factory.getExecutableSharedParameterTypes(method),
2470 parameterTypes)) {
2471 result.add(factory.copyMethod(method));
2472 }
2473 }
2474 return result;
2475 }
2476
2477 /**
2478 * Returns the most specific {@code Method} object of this class, super class or
2479 * interface that have the specified method name and parameter types.
2480 *
2481 * @param publicOnly true if only public methods are examined, otherwise all methods
2482 * @param name the name of the method
2483 * @param parameterTypes the parameter array
2484 * @return the {@code Method} object for the method found from this class matching
2485 * the specified name and parameters, or null if not found
2486 */
2487 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2488 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2489 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2490 }
2491
2492 /**
2493 * Returns a {@code Constructor} object that reflects the specified
2494 * constructor of the class represented by this
2495 * {@code Class} object. The {@code parameterTypes} parameter is
2496 * an array of {@code Class} objects that identify the constructor's
2497 * formal parameter types, in declared order.
2498 *
2499 * If this {@code Class} object represents an inner class
2500 * declared in a non-static context, the formal parameter types
2501 * include the explicit enclosing instance as the first parameter.
2502 *
2503 * @param parameterTypes the parameter array
2504 * @return The {@code Constructor} object for the constructor with the
2505 * specified parameter list
2506 * @throws NoSuchMethodException if a matching constructor is not found,
2507 * including when this {@code Class} object represents
2508 * an interface, a primitive type, an array class, or void.
2509 *
2510 * @see #getConstructor(Class[])
2511 * @since 1.1
2512 */
2513 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2514 throws NoSuchMethodException {
2515 return getReflectionFactory().copyConstructor(
2516 getConstructor0(parameterTypes, Member.DECLARED));
2517 }
2518
2519 /**
2520 * Finds a resource with a given name.
2521 *
2522 * <p> If this class is in a named {@link Module Module} then this method
2523 * will attempt to find the resource in the module. This is done by
2524 * delegating to the module's class loader {@link
2525 * ClassLoader#findResource(String,String) findResource(String,String)}
2526 * method, invoking it with the module name and the absolute name of the
2527 * resource. Resources in named modules are subject to the rules for
2528 * encapsulation specified in the {@code Module} {@link
2529 * Module#getResourceAsStream getResourceAsStream} method and so this
2530 * method returns {@code null} when the resource is a
2531 * non-"{@code .class}" resource in a package that is not open to the
2532 * caller's module.
2533 *
2534 * <p> Otherwise, if this class is not in a named module then the rules for
2535 * searching resources associated with a given class are implemented by the
2536 * defining {@linkplain ClassLoader class loader} of the class. This method
2537 * delegates to this {@code Class} object's class loader.
2538 * If this {@code Class} object was loaded by the bootstrap class loader,
2539 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2540 *
2541 * <p> Before delegation, an absolute resource name is constructed from the
2542 * given resource name using this algorithm:
2543 *
2544 * <ul>
2545 *
2546 * <li> If the {@code name} begins with a {@code '/'}
2547 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2548 * portion of the {@code name} following the {@code '/'}.
2549 *
2550 * <li> Otherwise, the absolute name is of the following form:
2551 *
2552 * <blockquote>
2553 * {@code modified_package_name/name}
2554 * </blockquote>
2555 *
2556 * <p> Where the {@code modified_package_name} is the package name of this
2557 * object with {@code '/'} substituted for {@code '.'}
2558 * (<code>'\u002e'</code>).
2559 *
2560 * </ul>
2561 *
2562 * @param name name of the desired resource
2563 * @return A {@link java.io.InputStream} object; {@code null} if no
2564 * resource with this name is found, or the resource is in a package
2565 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2566 * least the caller module.
2567 * @throws NullPointerException If {@code name} is {@code null}
2568 *
2569 * @see Module#getResourceAsStream(String)
2570 * @since 1.1
2571 */
2572 @CallerSensitive
2573 public InputStream getResourceAsStream(String name) {
2574 name = resolveName(name);
2575
2576 Module thisModule = getModule();
2577 if (thisModule.isNamed()) {
2578 // check if resource can be located by caller
2579 if (Resources.canEncapsulate(name)
2580 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2581 return null;
2582 }
2583
2584 // resource not encapsulated or in package open to caller
2585 String mn = thisModule.getName();
2586 ClassLoader cl = classLoader;
2587 try {
2588
2589 // special-case built-in class loaders to avoid the
2590 // need for a URL connection
2591 if (cl == null) {
2592 return BootLoader.findResourceAsStream(mn, name);
2593 } else if (cl instanceof BuiltinClassLoader bcl) {
2594 return bcl.findResourceAsStream(mn, name);
2595 } else {
2596 URL url = cl.findResource(mn, name);
2597 return (url != null) ? url.openStream() : null;
2598 }
2599
2600 } catch (IOException | SecurityException e) {
2601 return null;
2602 }
2603 }
2604
2605 // unnamed module
2606 ClassLoader cl = classLoader;
2607 if (cl == null) {
2608 return ClassLoader.getSystemResourceAsStream(name);
2609 } else {
2610 return cl.getResourceAsStream(name);
2611 }
2612 }
2613
2614 /**
2615 * Finds a resource with a given name.
2616 *
2617 * <p> If this class is in a named {@link Module Module} then this method
2618 * will attempt to find the resource in the module. This is done by
2619 * delegating to the module's class loader {@link
2620 * ClassLoader#findResource(String,String) findResource(String,String)}
2621 * method, invoking it with the module name and the absolute name of the
2622 * resource. Resources in named modules are subject to the rules for
2623 * encapsulation specified in the {@code Module} {@link
2624 * Module#getResourceAsStream getResourceAsStream} method and so this
2625 * method returns {@code null} when the resource is a
2626 * non-"{@code .class}" resource in a package that is not open to the
2627 * caller's module.
2628 *
2629 * <p> Otherwise, if this class is not in a named module then the rules for
2630 * searching resources associated with a given class are implemented by the
2631 * defining {@linkplain ClassLoader class loader} of the class. This method
2632 * delegates to this {@code Class} object's class loader.
2633 * If this {@code Class} object was loaded by the bootstrap class loader,
2634 * the method delegates to {@link ClassLoader#getSystemResource}.
2635 *
2636 * <p> Before delegation, an absolute resource name is constructed from the
2637 * given resource name using this algorithm:
2638 *
2639 * <ul>
2640 *
2641 * <li> If the {@code name} begins with a {@code '/'}
2642 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2643 * portion of the {@code name} following the {@code '/'}.
2644 *
2645 * <li> Otherwise, the absolute name is of the following form:
2646 *
2647 * <blockquote>
2648 * {@code modified_package_name/name}
2649 * </blockquote>
2650 *
2651 * <p> Where the {@code modified_package_name} is the package name of this
2652 * object with {@code '/'} substituted for {@code '.'}
2653 * (<code>'\u002e'</code>).
2654 *
2655 * </ul>
2656 *
2657 * @param name name of the desired resource
2658 * @return A {@link java.net.URL} object; {@code null} if no resource with
2659 * this name is found, the resource cannot be located by a URL, or the
2660 * resource is in a package that is not
2661 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2662 * module.
2663 * @throws NullPointerException If {@code name} is {@code null}
2664 * @since 1.1
2665 */
2666 @CallerSensitive
2667 public URL getResource(String name) {
2668 name = resolveName(name);
2669
2670 Module thisModule = getModule();
2671 if (thisModule.isNamed()) {
2672 // check if resource can be located by caller
2673 if (Resources.canEncapsulate(name)
2674 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2675 return null;
2676 }
2677
2678 // resource not encapsulated or in package open to caller
2679 String mn = thisModule.getName();
2680 ClassLoader cl = classLoader;
2681 try {
2682 if (cl == null) {
2683 return BootLoader.findResource(mn, name);
2684 } else {
2685 return cl.findResource(mn, name);
2686 }
2687 } catch (IOException ioe) {
2688 return null;
2689 }
2690 }
2691
2692 // unnamed module
2693 ClassLoader cl = classLoader;
2694 if (cl == null) {
2695 return ClassLoader.getSystemResource(name);
2696 } else {
2697 return cl.getResource(name);
2698 }
2699 }
2700
2701 /**
2702 * Returns true if a resource with the given name can be located by the
2703 * given caller. All resources in a module can be located by code in
2704 * the module. For other callers, then the package needs to be open to
2705 * the caller.
2706 */
2707 private boolean isOpenToCaller(String name, Class<?> caller) {
2708 // assert getModule().isNamed();
2709 Module thisModule = getModule();
2710 Module callerModule = (caller != null) ? caller.getModule() : null;
2711 if (callerModule != thisModule) {
2712 String pn = Resources.toPackageName(name);
2713 if (thisModule.getDescriptor().packages().contains(pn)) {
2714 if (callerModule == null) {
2715 // no caller, return true if the package is open to all modules
2716 return thisModule.isOpen(pn);
2717 }
2718 if (!thisModule.isOpen(pn, callerModule)) {
2719 // package not open to caller
2720 return false;
2721 }
2722 }
2723 }
2724 return true;
2725 }
2726
2727 private transient final ProtectionDomain protectionDomain;
2728
2729 /** Holder for the protection domain returned when the internal domain is null */
2730 private static class Holder {
2731 private static final ProtectionDomain allPermDomain;
2732 static {
2733 Permissions perms = new Permissions();
2734 perms.add(new AllPermission());
2735 allPermDomain = new ProtectionDomain(null, perms);
2736 }
2737 }
2738
2739 /**
2740 * Returns the {@code ProtectionDomain} of this class.
2741 *
2742 * @return the ProtectionDomain of this class
2743 *
2744 * @see java.security.ProtectionDomain
2745 * @since 1.2
2746 */
2747 public ProtectionDomain getProtectionDomain() {
2748 if (protectionDomain == null) {
2749 return Holder.allPermDomain;
2750 } else {
2751 return protectionDomain;
2752 }
2753 }
2754
2755 /*
2756 * Returns the Class object for the named primitive type. Type parameter T
2757 * avoids redundant casts for trusted code.
2758 */
2759 static native <T> Class<T> getPrimitiveClass(String name);
2760
2761 /**
2762 * Add a package name prefix if the name is not absolute. Remove leading "/"
2763 * if name is absolute
2764 */
2765 private String resolveName(String name) {
2766 if (!name.startsWith("/")) {
2767 String baseName = getPackageName();
2768 if (!baseName.isEmpty()) {
2769 int len = baseName.length() + 1 + name.length();
2770 StringBuilder sb = new StringBuilder(len);
2771 name = sb.append(baseName.replace('.', '/'))
2772 .append('/')
2773 .append(name)
2774 .toString();
2775 }
2776 } else {
2777 name = name.substring(1);
2778 }
2779 return name;
2780 }
2781
2782 /**
2783 * Atomic operations support.
2784 */
2785 private static class Atomic {
2786 // initialize Unsafe machinery here, since we need to call Class.class instance method
2787 // and have to avoid calling it in the static initializer of the Class class...
2788 private static final Unsafe unsafe = Unsafe.getUnsafe();
2789 // offset of Class.reflectionData instance field
2790 private static final long reflectionDataOffset
2791 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2792 // offset of Class.annotationType instance field
2793 private static final long annotationTypeOffset
2794 = unsafe.objectFieldOffset(Class.class, "annotationType");
2795 // offset of Class.annotationData instance field
2796 private static final long annotationDataOffset
2797 = unsafe.objectFieldOffset(Class.class, "annotationData");
2798
2799 static <T> boolean casReflectionData(Class<?> clazz,
2800 ReflectionData<T> oldData,
2801 ReflectionData<T> newData) {
2802 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2803 }
2804
2805 static boolean casAnnotationType(Class<?> clazz,
2806 AnnotationType oldType,
2807 AnnotationType newType) {
2808 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2809 }
2810
2811 static boolean casAnnotationData(Class<?> clazz,
2812 AnnotationData oldData,
2813 AnnotationData newData) {
2814 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2815 }
2816 }
2817
2818 /**
2819 * Reflection support.
2820 */
2821
2822 // Reflection data caches various derived names and reflective members. Cached
2823 // values may be invalidated when JVM TI RedefineClasses() is called
2824 private static class ReflectionData<T> {
2825 volatile Field[] declaredFields;
2826 volatile Field[] publicFields;
2827 volatile Method[] declaredMethods;
2828 volatile Method[] publicMethods;
2829 volatile Constructor<T>[] declaredConstructors;
2830 volatile Constructor<T>[] publicConstructors;
2831 // Intermediate results for getFields and getMethods
2832 volatile Field[] declaredPublicFields;
2833 volatile Method[] declaredPublicMethods;
2834 volatile Class<?>[] interfaces;
2835
2836 // Cached names
2837 String simpleName;
2838 String canonicalName;
2839 static final String NULL_SENTINEL = new String();
2840
2841 // Value of classRedefinedCount when we created this ReflectionData instance
2842 final int redefinedCount;
2843
2844 ReflectionData(int redefinedCount) {
2845 this.redefinedCount = redefinedCount;
2846 }
2847 }
2848
2849 private transient volatile ReflectionData<T> reflectionData;
2850
2851 // Incremented by the VM on each call to JVM TI RedefineClasses()
2852 // that redefines this class or a superclass.
2853 private transient volatile int classRedefinedCount;
2854
2855 // Lazily create and cache ReflectionData
2856 private ReflectionData<T> reflectionData() {
2857 ReflectionData<T> reflectionData = this.reflectionData;
2858 int classRedefinedCount = this.classRedefinedCount;
2859 if (reflectionData != null &&
2860 reflectionData.redefinedCount == classRedefinedCount) {
2861 return reflectionData;
2862 }
2863 // else no SoftReference or cleared SoftReference or stale ReflectionData
2864 // -> create and replace new instance
2865 return newReflectionData(reflectionData, classRedefinedCount);
2866 }
2867
2868 private ReflectionData<T> newReflectionData(ReflectionData<T> oldReflectionData,
2869 int classRedefinedCount) {
2870 while (true) {
2871 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2872 // try to CAS it...
2873 if (Atomic.casReflectionData(this, oldReflectionData, rd)) {
2874 return rd;
2875 }
2876 // else retry
2877 oldReflectionData = this.reflectionData;
2878 classRedefinedCount = this.classRedefinedCount;
2879 if (oldReflectionData != null && oldReflectionData.redefinedCount == classRedefinedCount) {
2880 return rd;
2881 }
2882 }
2883 }
2884
2885 // Generic signature handling
2886 private native String getGenericSignature0();
2887
2888 // Generic info repository; lazily initialized
2889 private transient volatile ClassRepository genericInfo;
2890
2891 // accessor for factory
2892 private GenericsFactory getFactory() {
2893 // create scope and factory
2894 return CoreReflectionFactory.make(this, ClassScope.make(this));
2895 }
2896
2897 // accessor for generic info repository;
2898 // generic info is lazily initialized
2899 private ClassRepository getGenericInfo() {
2900 ClassRepository genericInfo = this.genericInfo;
2901 if (genericInfo == null) {
2902 String signature = getGenericSignature0();
2903 if (signature == null) {
2904 genericInfo = ClassRepository.NONE;
2905 } else {
2906 genericInfo = ClassRepository.make(signature, getFactory());
2907 }
2908 this.genericInfo = genericInfo;
2909 }
2910 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2911 }
2912
2913 // Annotations handling
2914 native byte[] getRawAnnotations();
2915 // Since 1.8
2916 native byte[] getRawTypeAnnotations();
2917 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2918 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2919 }
2920
2921 native ConstantPool getConstantPool();
2922
2923 //
2924 //
2925 // java.lang.reflect.Field handling
2926 //
2927 //
2928
2929 // Returns an array of "root" fields. These Field objects must NOT
2930 // be propagated to the outside world, but must instead be copied
2931 // via ReflectionFactory.copyField.
2932 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2933 Field[] res;
2934 ReflectionData<T> rd = reflectionData();
2935 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2936 if (res != null) return res;
2937 // No cached value available; request value from VM
2938 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2939 if (publicOnly) {
2940 rd.declaredPublicFields = res;
2941 } else {
2942 rd.declaredFields = res;
2943 }
2944 return res;
2945 }
2946
2947 // Returns an array of "root" fields. These Field objects must NOT
2948 // be propagated to the outside world, but must instead be copied
2949 // via ReflectionFactory.copyField.
2950 private Field[] privateGetPublicFields() {
2951 Field[] res;
2952 ReflectionData<T> rd = reflectionData();
2953 res = rd.publicFields;
2954 if (res != null) return res;
2955
2956 // Use a linked hash set to ensure order is preserved and
2957 // fields from common super interfaces are not duplicated
2958 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2959
2960 // Local fields
2961 addAll(fields, privateGetDeclaredFields(true));
2962
2963 // Direct superinterfaces, recursively
2964 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2965 addAll(fields, si.privateGetPublicFields());
2966 }
2967
2968 // Direct superclass, recursively
2969 Class<?> sc = getSuperclass();
2970 if (sc != null) {
2971 addAll(fields, sc.privateGetPublicFields());
2972 }
2973
2974 res = fields.toArray(new Field[0]);
2975 rd.publicFields = res;
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 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
2999 if (res != null) return res;
3000 // No cached value available; request value from VM
3001 if (isInterface()) {
3002 @SuppressWarnings("unchecked")
3003 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3004 res = temporaryRes;
3005 } else {
3006 res = getDeclaredConstructors0(publicOnly);
3007 }
3008 if (publicOnly) {
3009 rd.publicConstructors = res;
3010 } else {
3011 rd.declaredConstructors = res;
3012 }
3013 return res;
3014 }
3015
3016 //
3017 //
3018 // java.lang.reflect.Method handling
3019 //
3020 //
3021
3022 // Returns an array of "root" methods. These Method objects must NOT
3023 // be propagated to the outside world, but must instead be copied
3024 // via ReflectionFactory.copyMethod.
3025 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3026 Method[] res;
3027 ReflectionData<T> rd = reflectionData();
3028 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3029 if (res != null) return res;
3030 // No cached value available; request value from VM
3031 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3032 if (publicOnly) {
3033 rd.declaredPublicMethods = res;
3034 } else {
3035 rd.declaredMethods = res;
3036 }
3037 return res;
3038 }
3039
3040 // Returns an array of "root" methods. These Method objects must NOT
3041 // be propagated to the outside world, but must instead be copied
3042 // via ReflectionFactory.copyMethod.
3043 private Method[] privateGetPublicMethods() {
3044 Method[] res;
3045 ReflectionData<T> rd = reflectionData();
3046 res = rd.publicMethods;
3047 if (res != null) return res;
3048
3049 // No cached value available; compute value recursively.
3050 // Start by fetching public declared methods...
3051 PublicMethods pms = new PublicMethods();
3052 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3053 pms.merge(m);
3054 }
3055 // ...then recur over superclass methods...
3056 Class<?> sc = getSuperclass();
3057 if (sc != null) {
3058 for (Method m : sc.privateGetPublicMethods()) {
3059 pms.merge(m);
3060 }
3061 }
3062 // ...and finally over direct superinterfaces.
3063 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3064 for (Method m : intf.privateGetPublicMethods()) {
3065 // static interface methods are not inherited
3066 if (!Modifier.isStatic(m.getModifiers())) {
3067 pms.merge(m);
3068 }
3069 }
3070 }
3071
3072 res = pms.toArray();
3073 rd.publicMethods = res;
3074 return res;
3075 }
3076
3077
3078 //
3079 // Helpers for fetchers of one field, method, or constructor
3080 //
3081
3082 // This method does not copy the returned Field object!
3083 private static Field searchFields(Field[] fields, String name) {
3084 for (Field field : fields) {
3085 if (field.getName().equals(name)) {
3086 return field;
3087 }
3088 }
3089 return null;
3090 }
3091
3092 // Returns a "root" Field object. This Field object must NOT
3093 // be propagated to the outside world, but must instead be copied
3094 // via ReflectionFactory.copyField.
3095 private Field getField0(String name) {
3096 // Note: the intent is that the search algorithm this routine
3097 // uses be equivalent to the ordering imposed by
3098 // privateGetPublicFields(). It fetches only the declared
3099 // public fields for each class, however, to reduce the number
3100 // of Field objects which have to be created for the common
3101 // case where the field being requested is declared in the
3102 // class which is being queried.
3103 Field res;
3104 // Search declared public fields
3105 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3106 return res;
3107 }
3108 // Direct superinterfaces, recursively
3109 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3110 for (Class<?> c : interfaces) {
3111 if ((res = c.getField0(name)) != null) {
3112 return res;
3113 }
3114 }
3115 // Direct superclass, recursively
3116 if (!isInterface()) {
3117 Class<?> c = getSuperclass();
3118 if (c != null) {
3119 if ((res = c.getField0(name)) != null) {
3120 return res;
3121 }
3122 }
3123 }
3124 return null;
3125 }
3126
3127 // This method does not copy the returned Method object!
3128 private static Method searchMethods(Method[] methods,
3129 String name,
3130 Class<?>[] parameterTypes)
3131 {
3132 ReflectionFactory fact = getReflectionFactory();
3133 Method res = null;
3134 for (Method m : methods) {
3135 if (m.getName().equals(name)
3136 && arrayContentsEq(parameterTypes,
3137 fact.getExecutableSharedParameterTypes(m))
3138 && (res == null
3139 || (res.getReturnType() != m.getReturnType()
3140 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3141 res = m;
3142 }
3143 return res;
3144 }
3145
3146 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3147
3148 // Returns a "root" Method object. This Method object must NOT
3149 // be propagated to the outside world, but must instead be copied
3150 // via ReflectionFactory.copyMethod.
3151 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3152 PublicMethods.MethodList res = getMethodsRecursive(
3153 name,
3154 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3155 /* includeStatic */ true, /* publicOnly */ true);
3156 return res == null ? null : res.getMostSpecific();
3157 }
3158
3159 // Returns a list of "root" Method objects. These Method objects must NOT
3160 // be propagated to the outside world, but must instead be copied
3161 // via ReflectionFactory.copyMethod.
3162 private PublicMethods.MethodList getMethodsRecursive(String name,
3163 Class<?>[] parameterTypes,
3164 boolean includeStatic,
3165 boolean publicOnly) {
3166 // 1st check declared methods
3167 Method[] methods = privateGetDeclaredMethods(publicOnly);
3168 PublicMethods.MethodList res = PublicMethods.MethodList
3169 .filter(methods, name, parameterTypes, includeStatic);
3170 // if there is at least one match among declared methods, we need not
3171 // search any further as such match surely overrides matching methods
3172 // declared in superclass(es) or interface(s).
3173 if (res != null) {
3174 return res;
3175 }
3176
3177 // if there was no match among declared methods,
3178 // we must consult the superclass (if any) recursively...
3179 Class<?> sc = getSuperclass();
3180 if (sc != null) {
3181 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3182 }
3183
3184 // ...and coalesce the superclass methods with methods obtained
3185 // from directly implemented interfaces excluding static methods...
3186 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3187 res = PublicMethods.MethodList.merge(
3188 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3189 }
3190
3191 return res;
3192 }
3193
3194 // Returns a "root" Constructor object. This Constructor object must NOT
3195 // be propagated to the outside world, but must instead be copied
3196 // via ReflectionFactory.copyConstructor.
3197 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3198 int which) throws NoSuchMethodException
3199 {
3200 ReflectionFactory fact = getReflectionFactory();
3201 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3202 for (Constructor<T> constructor : constructors) {
3203 if (arrayContentsEq(parameterTypes,
3204 fact.getExecutableSharedParameterTypes(constructor))) {
3205 return constructor;
3206 }
3207 }
3208 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3209 }
3210
3211 //
3212 // Other helpers and base implementation
3213 //
3214
3215 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3216 if (a1 == null) {
3217 return a2 == null || a2.length == 0;
3218 }
3219
3220 if (a2 == null) {
3221 return a1.length == 0;
3222 }
3223
3224 if (a1.length != a2.length) {
3225 return false;
3226 }
3227
3228 for (int i = 0; i < a1.length; i++) {
3229 if (a1[i] != a2[i]) {
3230 return false;
3231 }
3232 }
3233
3234 return true;
3235 }
3236
3237 private static Field[] copyFields(Field[] arg) {
3238 Field[] out = new Field[arg.length];
3239 ReflectionFactory fact = getReflectionFactory();
3240 for (int i = 0; i < arg.length; i++) {
3241 out[i] = fact.copyField(arg[i]);
3242 }
3243 return out;
3244 }
3245
3246 private static Method[] copyMethods(Method[] arg) {
3247 Method[] out = new Method[arg.length];
3248 ReflectionFactory fact = getReflectionFactory();
3249 for (int i = 0; i < arg.length; i++) {
3250 out[i] = fact.copyMethod(arg[i]);
3251 }
3252 return out;
3253 }
3254
3255 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3256 Constructor<U>[] out = arg.clone();
3257 ReflectionFactory fact = getReflectionFactory();
3258 for (int i = 0; i < out.length; i++) {
3259 out[i] = fact.copyConstructor(out[i]);
3260 }
3261 return out;
3262 }
3263
3264 private native Field[] getDeclaredFields0(boolean publicOnly);
3265 private native Method[] getDeclaredMethods0(boolean publicOnly);
3266 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3267 private native Class<?>[] getDeclaredClasses0();
3268
3269 /*
3270 * Returns an array containing the components of the Record attribute,
3271 * or null if the attribute is not present.
3272 *
3273 * Note that this method returns non-null array on a class with
3274 * the Record attribute even if this class is not a record.
3275 */
3276 private native RecordComponent[] getRecordComponents0();
3277 private native boolean isRecord0();
3278
3279 /**
3280 * Helper method to get the method name from arguments.
3281 */
3282 private String methodToString(String name, Class<?>[] argTypes) {
3283 return getName() + '.' + name +
3284 ((argTypes == null || argTypes.length == 0) ?
3285 "()" :
3286 Arrays.stream(argTypes)
3287 .map(c -> c == null ? "null" : c.getName())
3288 .collect(Collectors.joining(",", "(", ")")));
3289 }
3290
3291 /** use serialVersionUID from JDK 1.1 for interoperability */
3292 @java.io.Serial
3293 private static final long serialVersionUID = 3206093459760846163L;
3294
3295
3296 /**
3297 * Class Class is special cased within the Serialization Stream Protocol.
3298 *
3299 * A Class instance is written initially into an ObjectOutputStream in the
3300 * following format:
3301 * <pre>
3302 * {@code TC_CLASS} ClassDescriptor
3303 * A ClassDescriptor is a special cased serialization of
3304 * a {@code java.io.ObjectStreamClass} instance.
3305 * </pre>
3306 * A new handle is generated for the initial time the class descriptor
3307 * is written into the stream. Future references to the class descriptor
3308 * are written as references to the initial class descriptor instance.
3309 *
3310 * @see java.io.ObjectStreamClass
3311 */
3312 @java.io.Serial
3313 private static final ObjectStreamField[] serialPersistentFields =
3314 new ObjectStreamField[0];
3315
3316
3317 /**
3318 * Returns the assertion status that would be assigned to this
3319 * class if it were to be initialized at the time this method is invoked.
3320 * If this class has had its assertion status set, the most recent
3321 * setting will be returned; otherwise, if any package default assertion
3322 * status pertains to this class, the most recent setting for the most
3323 * specific pertinent package default assertion status is returned;
3324 * otherwise, if this class is not a system class (i.e., it has a
3325 * class loader) its class loader's default assertion status is returned;
3326 * otherwise, the system class default assertion status is returned.
3327 *
3328 * @apiNote
3329 * Few programmers will have any need for this method; it is provided
3330 * for the benefit of the JDK itself. (It allows a class to determine at
3331 * the time that it is initialized whether assertions should be enabled.)
3332 * Note that this method is not guaranteed to return the actual
3333 * assertion status that was (or will be) associated with the specified
3334 * class when it was (or will be) initialized.
3335 *
3336 * @return the desired assertion status of the specified class.
3337 * @see java.lang.ClassLoader#setClassAssertionStatus
3338 * @see java.lang.ClassLoader#setPackageAssertionStatus
3339 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3340 * @since 1.4
3341 */
3342 public boolean desiredAssertionStatus() {
3343 ClassLoader loader = classLoader;
3344 // If the loader is null this is a system class, so ask the VM
3345 if (loader == null)
3346 return desiredAssertionStatus0(this);
3347
3348 // If the classloader has been initialized with the assertion
3349 // directives, ask it. Otherwise, ask the VM.
3350 synchronized(loader.assertionLock) {
3351 if (loader.classAssertionStatus != null) {
3352 return loader.desiredAssertionStatus(getName());
3353 }
3354 }
3355 return desiredAssertionStatus0(this);
3356 }
3357
3358 // Retrieves the desired assertion status of this class from the VM
3359 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3360
3361 /**
3362 * Returns true if and only if this class was declared as an enum in the
3363 * source code.
3364 *
3365 * Note that {@link java.lang.Enum} is not itself an enum class.
3366 *
3367 * Also note that if an enum constant is declared with a class body,
3368 * the class of that enum constant object is an anonymous class
3369 * and <em>not</em> the class of the declaring enum class. The
3370 * {@link Enum#getDeclaringClass} method of an enum constant can
3371 * be used to get the class of the enum class declaring the
3372 * constant.
3373 *
3374 * @return true if and only if this class was declared as an enum in the
3375 * source code
3376 * @since 1.5
3377 * @jls 8.9.1 Enum Constants
3378 */
3379 public boolean isEnum() {
3380 // An enum must both directly extend java.lang.Enum and have
3381 // the ENUM bit set; classes for specialized enum constants
3382 // don't do the former.
3383 return (this.getModifiers() & ENUM) != 0 &&
3384 this.getSuperclass() == java.lang.Enum.class;
3385 }
3386
3387 /**
3388 * Returns {@code true} if and only if this class is a record class.
3389 *
3390 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3391 * class is {@code java.lang.Record}. A record class is {@linkplain
3392 * Modifier#FINAL final}. A record class has (possibly zero) record
3393 * components; {@link #getRecordComponents()} returns a non-null but
3394 * possibly empty value for a record.
3395 *
3396 * <p> Note that class {@link Record} is not a record class and thus
3397 * invoking this method on class {@code Record} returns {@code false}.
3398 *
3399 * @return true if and only if this class is a record class, otherwise false
3400 * @jls 8.10 Record Classes
3401 * @since 16
3402 */
3403 public boolean isRecord() {
3404 // this superclass and final modifier check is not strictly necessary
3405 // they are intrinsified and serve as a fast-path check
3406 return getSuperclass() == java.lang.Record.class &&
3407 (this.getModifiers() & Modifier.FINAL) != 0 &&
3408 isRecord0();
3409 }
3410
3411 // Fetches the factory for reflective objects
3412 private static ReflectionFactory getReflectionFactory() {
3413 var factory = reflectionFactory;
3414 if (factory != null) {
3415 return factory;
3416 }
3417 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3418 }
3419 private static ReflectionFactory reflectionFactory;
3420
3421 /**
3422 * When CDS is enabled, the Class class may be aot-initialized. However,
3423 * we can't archive reflectionFactory, so we reset it to null, so it
3424 * will be allocated again at runtime.
3425 */
3426 private static void resetArchivedStates() {
3427 reflectionFactory = null;
3428 }
3429
3430 /**
3431 * Returns the elements of this enum class or null if this
3432 * Class object does not represent an enum class.
3433 *
3434 * @return an array containing the values comprising the enum class
3435 * represented by this {@code Class} object in the order they're
3436 * declared, or null if this {@code Class} object does not
3437 * represent an enum class
3438 * @since 1.5
3439 * @jls 8.9.1 Enum Constants
3440 */
3441 public T[] getEnumConstants() {
3442 T[] values = getEnumConstantsShared();
3443 return (values != null) ? values.clone() : null;
3444 }
3445
3446 /**
3447 * Returns the elements of this enum class or null if this
3448 * Class object does not represent an enum class;
3449 * identical to getEnumConstants except that the result is
3450 * uncloned, cached, and shared by all callers.
3451 */
3452 T[] getEnumConstantsShared() {
3453 T[] constants = enumConstants;
3454 if (constants == null) {
3455 if (!isEnum()) return null;
3456 try {
3457 final Method values = getMethod("values");
3458 values.setAccessible(true);
3459 @SuppressWarnings("unchecked")
3460 T[] temporaryConstants = (T[])values.invoke(null);
3461 enumConstants = constants = temporaryConstants;
3462 }
3463 // These can happen when users concoct enum-like classes
3464 // that don't comply with the enum spec.
3465 catch (InvocationTargetException | NoSuchMethodException |
3466 IllegalAccessException | NullPointerException |
3467 ClassCastException ex) { return null; }
3468 }
3469 return constants;
3470 }
3471 private transient volatile T[] enumConstants;
3472
3473 /**
3474 * Returns a map from simple name to enum constant. This package-private
3475 * method is used internally by Enum to implement
3476 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3477 * efficiently. Note that the map is returned by this method is
3478 * created lazily on first use. Typically it won't ever get created.
3479 */
3480 Map<String, T> enumConstantDirectory() {
3481 Map<String, T> directory = enumConstantDirectory;
3482 if (directory == null) {
3483 T[] universe = getEnumConstantsShared();
3484 if (universe == null)
3485 throw new IllegalArgumentException(
3486 getName() + " is not an enum class");
3487 directory = HashMap.newHashMap(universe.length);
3488 for (T constant : universe) {
3489 directory.put(((Enum<?>)constant).name(), constant);
3490 }
3491 enumConstantDirectory = directory;
3492 }
3493 return directory;
3494 }
3495 private transient volatile Map<String, T> enumConstantDirectory;
3496
3497 /**
3498 * Casts an object to the class or interface represented
3499 * by this {@code Class} object.
3500 *
3501 * @param obj the object to be cast
3502 * @return the object after casting, or null if obj is null
3503 *
3504 * @throws ClassCastException if the object is not
3505 * null and is not assignable to the type T.
3506 *
3507 * @since 1.5
3508 */
3509 @SuppressWarnings("unchecked")
3510 @IntrinsicCandidate
3511 public T cast(Object obj) {
3512 if (obj != null && !isInstance(obj))
3513 throw new ClassCastException(cannotCastMsg(obj));
3514 return (T) obj;
3515 }
3516
3517 private String cannotCastMsg(Object obj) {
3518 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3519 }
3520
3521 /**
3522 * Casts this {@code Class} object to represent a subclass of the class
3523 * represented by the specified class object. Checks that the cast
3524 * is valid, and throws a {@code ClassCastException} if it is not. If
3525 * this method succeeds, it always returns a reference to this {@code Class} object.
3526 *
3527 * <p>This method is useful when a client needs to "narrow" the type of
3528 * a {@code Class} object to pass it to an API that restricts the
3529 * {@code Class} objects that it is willing to accept. A cast would
3530 * generate a compile-time warning, as the correctness of the cast
3531 * could not be checked at runtime (because generic types are implemented
3532 * by erasure).
3533 *
3534 * @param <U> the type to cast this {@code Class} object to
3535 * @param clazz the class of the type to cast this {@code Class} object to
3536 * @return this {@code Class} object, cast to represent a subclass of
3537 * the specified class object.
3538 * @throws ClassCastException if this {@code Class} object does not
3539 * represent a subclass of the specified class (here "subclass" includes
3540 * the class itself).
3541 * @since 1.5
3542 */
3543 @SuppressWarnings("unchecked")
3544 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3545 if (clazz.isAssignableFrom(this))
3546 return (Class<? extends U>) this;
3547 else
3548 throw new ClassCastException(this.toString());
3549 }
3550
3551 /**
3552 * {@inheritDoc}
3553 * <p>Note that any annotation returned by this method is a
3554 * declaration annotation.
3555 *
3556 * @throws NullPointerException {@inheritDoc}
3557 * @since 1.5
3558 */
3559 @Override
3560 @SuppressWarnings("unchecked")
3561 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3562 Objects.requireNonNull(annotationClass);
3563
3564 return (A) annotationData().annotations.get(annotationClass);
3565 }
3566
3567 /**
3568 * {@inheritDoc}
3569 * @throws NullPointerException {@inheritDoc}
3570 * @since 1.5
3571 */
3572 @Override
3573 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3574 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3575 }
3576
3577 /**
3578 * {@inheritDoc}
3579 * <p>Note that any annotations returned by this method are
3580 * declaration annotations.
3581 *
3582 * @throws NullPointerException {@inheritDoc}
3583 * @since 1.8
3584 */
3585 @Override
3586 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3587 Objects.requireNonNull(annotationClass);
3588
3589 AnnotationData annotationData = annotationData();
3590 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3591 this,
3592 annotationClass);
3593 }
3594
3595 /**
3596 * {@inheritDoc}
3597 * <p>Note that any annotations returned by this method are
3598 * declaration annotations.
3599 *
3600 * @since 1.5
3601 */
3602 @Override
3603 public Annotation[] getAnnotations() {
3604 return AnnotationParser.toArray(annotationData().annotations);
3605 }
3606
3607 /**
3608 * {@inheritDoc}
3609 * <p>Note that any annotation returned by this method is a
3610 * declaration annotation.
3611 *
3612 * @throws NullPointerException {@inheritDoc}
3613 * @since 1.8
3614 */
3615 @Override
3616 @SuppressWarnings("unchecked")
3617 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3618 Objects.requireNonNull(annotationClass);
3619
3620 return (A) annotationData().declaredAnnotations.get(annotationClass);
3621 }
3622
3623 /**
3624 * {@inheritDoc}
3625 * <p>Note that any annotations returned by this method are
3626 * declaration annotations.
3627 *
3628 * @throws NullPointerException {@inheritDoc}
3629 * @since 1.8
3630 */
3631 @Override
3632 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3633 Objects.requireNonNull(annotationClass);
3634
3635 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3636 annotationClass);
3637 }
3638
3639 /**
3640 * {@inheritDoc}
3641 * <p>Note that any annotations returned by this method are
3642 * declaration annotations.
3643 *
3644 * @since 1.5
3645 */
3646 @Override
3647 public Annotation[] getDeclaredAnnotations() {
3648 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3649 }
3650
3651 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3652 private static class AnnotationData {
3653 final Map<Class<? extends Annotation>, Annotation> annotations;
3654 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3655
3656 // Value of classRedefinedCount when we created this AnnotationData instance
3657 final int redefinedCount;
3658
3659 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3660 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3661 int redefinedCount) {
3662 this.annotations = annotations;
3663 this.declaredAnnotations = declaredAnnotations;
3664 this.redefinedCount = redefinedCount;
3665 }
3666 }
3667
3668 // Annotations cache
3669 @SuppressWarnings("UnusedDeclaration")
3670 private transient volatile AnnotationData annotationData;
3671
3672 private AnnotationData annotationData() {
3673 while (true) { // retry loop
3674 AnnotationData annotationData = this.annotationData;
3675 int classRedefinedCount = this.classRedefinedCount;
3676 if (annotationData != null &&
3677 annotationData.redefinedCount == classRedefinedCount) {
3678 return annotationData;
3679 }
3680 // null or stale annotationData -> optimistically create new instance
3681 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3682 // try to install it
3683 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3684 // successfully installed new AnnotationData
3685 return newAnnotationData;
3686 }
3687 }
3688 }
3689
3690 private AnnotationData createAnnotationData(int classRedefinedCount) {
3691 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3692 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3693 Class<?> superClass = getSuperclass();
3694 Map<Class<? extends Annotation>, Annotation> annotations = null;
3695 if (superClass != null) {
3696 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3697 superClass.annotationData().annotations;
3698 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3699 Class<? extends Annotation> annotationClass = e.getKey();
3700 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3701 if (annotations == null) { // lazy construction
3702 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3703 declaredAnnotations.size(),
3704 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3705 )
3706 );
3707 }
3708 annotations.put(annotationClass, e.getValue());
3709 }
3710 }
3711 }
3712 if (annotations == null) {
3713 // no inherited annotations -> share the Map with declaredAnnotations
3714 annotations = declaredAnnotations;
3715 } else {
3716 // at least one inherited annotation -> declared may override inherited
3717 annotations.putAll(declaredAnnotations);
3718 }
3719 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3720 }
3721
3722 // Annotation interfaces cache their internal (AnnotationType) form
3723
3724 @SuppressWarnings("UnusedDeclaration")
3725 private transient volatile AnnotationType annotationType;
3726
3727 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3728 return Atomic.casAnnotationType(this, oldType, newType);
3729 }
3730
3731 AnnotationType getAnnotationType() {
3732 return annotationType;
3733 }
3734
3735 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3736 return annotationData().declaredAnnotations;
3737 }
3738
3739 /* Backing store of user-defined values pertaining to this class.
3740 * Maintained by the ClassValue class.
3741 */
3742 transient ClassValue.ClassValueMap classValueMap;
3743
3744 /**
3745 * Returns an {@code AnnotatedType} object that represents the use of a
3746 * type to specify the superclass of the entity represented by this {@code
3747 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3748 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3749 * Foo.)
3750 *
3751 * <p> If this {@code Class} object represents a class whose declaration
3752 * does not explicitly indicate an annotated superclass, then the return
3753 * value is an {@code AnnotatedType} object representing an element with no
3754 * annotations.
3755 *
3756 * <p> If this {@code Class} represents either the {@code Object} class, an
3757 * interface type, an array type, a primitive type, or void, the return
3758 * value is {@code null}.
3759 *
3760 * @return an object representing the superclass
3761 * @since 1.8
3762 */
3763 public AnnotatedType getAnnotatedSuperclass() {
3764 if (this == Object.class ||
3765 isInterface() ||
3766 isArray() ||
3767 isPrimitive() ||
3768 this == Void.TYPE) {
3769 return null;
3770 }
3771
3772 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3773 }
3774
3775 /**
3776 * Returns an array of {@code AnnotatedType} objects that represent the use
3777 * of types to specify superinterfaces of the entity represented by this
3778 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3779 * superinterface in '... implements Foo' is distinct from the
3780 * <em>declaration</em> of interface Foo.)
3781 *
3782 * <p> If this {@code Class} object represents a class, the return value is
3783 * an array containing objects representing the uses of interface types to
3784 * specify interfaces implemented by the class. The order of the objects in
3785 * the array corresponds to the order of the interface types used in the
3786 * 'implements' clause of the declaration of this {@code Class} object.
3787 *
3788 * <p> If this {@code Class} object represents an interface, the return
3789 * value is an array containing objects representing the uses of interface
3790 * types to specify interfaces directly extended by the interface. The
3791 * order of the objects in the array corresponds to the order of the
3792 * interface types used in the 'extends' clause of the declaration of this
3793 * {@code Class} object.
3794 *
3795 * <p> If this {@code Class} object represents a class or interface whose
3796 * declaration does not explicitly indicate any annotated superinterfaces,
3797 * the return value is an array of length 0.
3798 *
3799 * <p> If this {@code Class} object represents either the {@code Object}
3800 * class, an array type, a primitive type, or void, the return value is an
3801 * array of length 0.
3802 *
3803 * @return an array representing the superinterfaces
3804 * @since 1.8
3805 */
3806 public AnnotatedType[] getAnnotatedInterfaces() {
3807 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3808 }
3809
3810 private native Class<?> getNestHost0();
3811
3812 /**
3813 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3814 * or interface represented by this {@code Class} object belongs.
3815 * Every class and interface belongs to exactly one nest.
3816 *
3817 * If the nest host of this class or interface has previously
3818 * been determined, then this method returns the nest host.
3819 * If the nest host of this class or interface has
3820 * not previously been determined, then this method determines the nest
3821 * host using the algorithm of JVMS 5.4.4, and returns it.
3822 *
3823 * Often, a class or interface belongs to a nest consisting only of itself,
3824 * in which case this method returns {@code this} to indicate that the class
3825 * or interface is the nest host.
3826 *
3827 * <p>If this {@code Class} object represents a primitive type, an array type,
3828 * or {@code void}, then this method returns {@code this},
3829 * indicating that the represented entity belongs to the nest consisting only of
3830 * itself, and is the nest host.
3831 *
3832 * @return the nest host of this class or interface
3833 *
3834 * @since 11
3835 * @jvms 4.7.28 The {@code NestHost} Attribute
3836 * @jvms 4.7.29 The {@code NestMembers} Attribute
3837 * @jvms 5.4.4 Access Control
3838 */
3839 public Class<?> getNestHost() {
3840 if (isPrimitive() || isArray()) {
3841 return this;
3842 }
3843 return getNestHost0();
3844 }
3845
3846 /**
3847 * Determines if the given {@code Class} is a nestmate of the
3848 * class or interface represented by this {@code Class} object.
3849 * Two classes or interfaces are nestmates
3850 * if they have the same {@linkplain #getNestHost() nest host}.
3851 *
3852 * @param c the class to check
3853 * @return {@code true} if this class and {@code c} are members of
3854 * the same nest; and {@code false} otherwise.
3855 *
3856 * @since 11
3857 */
3858 public boolean isNestmateOf(Class<?> c) {
3859 if (this == c) {
3860 return true;
3861 }
3862 if (isPrimitive() || isArray() ||
3863 c.isPrimitive() || c.isArray()) {
3864 return false;
3865 }
3866
3867 return getNestHost() == c.getNestHost();
3868 }
3869
3870 private native Class<?>[] getNestMembers0();
3871
3872 /**
3873 * Returns an array containing {@code Class} objects representing all the
3874 * classes and interfaces that are members of the nest to which the class
3875 * or interface represented by this {@code Class} object belongs.
3876 *
3877 * First, this method obtains the {@linkplain #getNestHost() nest host},
3878 * {@code H}, of the nest to which the class or interface represented by
3879 * this {@code Class} object belongs. The zeroth element of the returned
3880 * array is {@code H}.
3881 *
3882 * Then, for each class or interface {@code C} which is recorded by {@code H}
3883 * as being a member of its nest, this method attempts to obtain the {@code Class}
3884 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3885 * loader} of the current {@code Class} object), and then obtains the
3886 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3887 * The classes and interfaces which are recorded by {@code H} as being members
3888 * of its nest, and for which {@code H} can be determined as their nest host,
3889 * are indicated by subsequent elements of the returned array. The order of
3890 * such elements is unspecified. Duplicates are permitted.
3891 *
3892 * <p>If this {@code Class} object represents a primitive type, an array type,
3893 * or {@code void}, then this method returns a single-element array containing
3894 * {@code this}.
3895 *
3896 * @apiNote
3897 * The returned array includes only the nest members recorded in the {@code NestMembers}
3898 * attribute, and not any hidden classes that were added to the nest via
3899 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3900 * Lookup::defineHiddenClass}.
3901 *
3902 * @return an array of all classes and interfaces in the same nest as
3903 * this class or interface
3904 *
3905 * @since 11
3906 * @see #getNestHost()
3907 * @jvms 4.7.28 The {@code NestHost} Attribute
3908 * @jvms 4.7.29 The {@code NestMembers} Attribute
3909 */
3910 public Class<?>[] getNestMembers() {
3911 if (isPrimitive() || isArray()) {
3912 return new Class<?>[] { this };
3913 }
3914 Class<?>[] members = getNestMembers0();
3915 // Can't actually enable this due to bootstrapping issues
3916 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3917 return members;
3918 }
3919
3920 /**
3921 * Returns the descriptor string of the entity (class, interface, array class,
3922 * primitive type, or {@code void}) represented by this {@code Class} object.
3923 *
3924 * <p> If this {@code Class} object represents a class or interface,
3925 * not an array class, then:
3926 * <ul>
3927 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3928 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3929 * for the class or interface. Calling
3930 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3931 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3932 * describing this class or interface.
3933 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3934 * then the result is a string of the form:
3935 * <blockquote>
3936 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3937 * </blockquote>
3938 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3939 * encoded in internal form indicated by the {@code class} file passed to
3940 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3941 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3942 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3943 * The result string is not a type descriptor.
3944 * </ul>
3945 *
3946 * <p> If this {@code Class} object represents an array class, then
3947 * the result is a string consisting of one or more '{@code [}' characters
3948 * representing the depth of the array nesting, followed by the
3949 * descriptor string of the element type.
3950 * <ul>
3951 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3952 * or interface, then this array class can be described nominally.
3953 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3954 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3955 * describing this array class.
3956 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3957 * interface, then this array class cannot be described nominally.
3958 * The result string is not a type descriptor.
3959 * </ul>
3960 *
3961 * <p> If this {@code Class} object represents a primitive type or
3962 * {@code void}, then the result is a field descriptor string which
3963 * is a one-letter code corresponding to a primitive type or {@code void}
3964 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3965 *
3966 * @return the descriptor string for this {@code Class} object
3967 * @jvms 4.3.2 Field Descriptors
3968 * @since 12
3969 */
3970 @Override
3971 public String descriptorString() {
3972 if (isPrimitive())
3973 return Wrapper.forPrimitiveType(this).basicTypeString();
3974
3975 if (isArray()) {
3976 return "[".concat(componentType.descriptorString());
3977 } else if (isHidden()) {
3978 String name = getName();
3979 int index = name.indexOf('/');
3980 return new StringBuilder(name.length() + 2)
3981 .append('L')
3982 .append(name.substring(0, index).replace('.', '/'))
3983 .append('.')
3984 .append(name, index + 1, name.length())
3985 .append(';')
3986 .toString();
3987 } else {
3988 String name = getName().replace('.', '/');
3989 return StringConcatHelper.concat("L", name, ";");
3990 }
3991 }
3992
3993 /**
3994 * Returns the component type of this {@code Class}, if it describes
3995 * an array type, or {@code null} otherwise.
3996 *
3997 * @implSpec
3998 * Equivalent to {@link Class#getComponentType()}.
3999 *
4000 * @return a {@code Class} describing the component type, or {@code null}
4001 * if this {@code Class} does not describe an array type
4002 * @since 12
4003 */
4004 @Override
4005 public Class<?> componentType() {
4006 return getComponentType();
4007 }
4008
4009 /**
4010 * Returns a {@code Class} for an array type whose component type
4011 * is described by this {@linkplain Class}.
4012 *
4013 * @throws UnsupportedOperationException if this component type is {@linkplain
4014 * Void#TYPE void} or if the number of dimensions of the resulting array
4015 * type would exceed 255.
4016 * @return a {@code Class} describing the array type
4017 * @jvms 4.3.2 Field Descriptors
4018 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4019 * @since 12
4020 */
4021 @Override
4022 public Class<?> arrayType() {
4023 try {
4024 return Array.newInstance(this, 0).getClass();
4025 } catch (IllegalArgumentException iae) {
4026 throw new UnsupportedOperationException(iae);
4027 }
4028 }
4029
4030 /**
4031 * Returns a nominal descriptor for this instance, if one can be
4032 * constructed, or an empty {@link Optional} if one cannot be.
4033 *
4034 * @return An {@link Optional} containing the resulting nominal descriptor,
4035 * or an empty {@link Optional} if one cannot be constructed.
4036 * @since 12
4037 */
4038 @Override
4039 public Optional<ClassDesc> describeConstable() {
4040 Class<?> c = isArray() ? elementType() : this;
4041 return c.isHidden() ? Optional.empty()
4042 : Optional.of(ConstantUtils.classDesc(this));
4043 }
4044
4045 /**
4046 * Returns {@code true} if and only if the underlying class is a hidden class.
4047 *
4048 * @return {@code true} if and only if this class is a hidden class.
4049 *
4050 * @since 15
4051 * @see MethodHandles.Lookup#defineHiddenClass
4052 * @see Class##hiddenClasses Hidden Classes
4053 */
4054 @IntrinsicCandidate
4055 public native boolean isHidden();
4056
4057 /**
4058 * Returns an array containing {@code Class} objects representing the
4059 * direct subinterfaces or subclasses permitted to extend or
4060 * implement this class or interface if it is sealed. The order of such elements
4061 * is unspecified. The array is empty if this sealed class or interface has no
4062 * permitted subclass. If this {@code Class} object represents a primitive type,
4063 * {@code void}, an array type, or a class or interface that is not sealed,
4064 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4065 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4066 * returns a non-null value.
4067 *
4068 * For each class or interface {@code C} which is recorded as a permitted
4069 * direct subinterface or subclass of this class or interface,
4070 * this method attempts to obtain the {@code Class}
4071 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4072 * loader} of the current {@code Class} object).
4073 * The {@code Class} objects which can be obtained and which are direct
4074 * subinterfaces or subclasses of this class or interface,
4075 * are indicated by elements of the returned array. If a {@code Class} object
4076 * cannot be obtained, it is silently ignored, and not included in the result
4077 * array.
4078 *
4079 * @return an array of {@code Class} objects of the permitted subclasses of this class
4080 * or interface, or {@code null} if this class or interface is not sealed.
4081 *
4082 * @jls 8.1 Class Declarations
4083 * @jls 9.1 Interface Declarations
4084 * @since 17
4085 */
4086 public Class<?>[] getPermittedSubclasses() {
4087 Class<?>[] subClasses;
4088 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4089 return null;
4090 }
4091 if (subClasses.length > 0) {
4092 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4093 subClasses = Arrays.stream(subClasses)
4094 .filter(this::isDirectSubType)
4095 .toArray(s -> new Class<?>[s]);
4096 }
4097 }
4098 return subClasses;
4099 }
4100
4101 private boolean isDirectSubType(Class<?> c) {
4102 if (isInterface()) {
4103 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4104 if (i == this) {
4105 return true;
4106 }
4107 }
4108 } else {
4109 return c.getSuperclass() == this;
4110 }
4111 return false;
4112 }
4113
4114 /**
4115 * Returns {@code true} if and only if this {@code Class} object represents
4116 * a sealed class or interface. If this {@code Class} object represents a
4117 * primitive type, {@code void}, or an array type, this method returns
4118 * {@code false}. A sealed class or interface has (possibly zero) permitted
4119 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4120 * possibly empty value for a sealed class or interface.
4121 *
4122 * @return {@code true} if and only if this {@code Class} object represents
4123 * a sealed class or interface.
4124 *
4125 * @jls 8.1 Class Declarations
4126 * @jls 9.1 Interface Declarations
4127 * @since 17
4128 */
4129 public boolean isSealed() {
4130 if (isArray() || isPrimitive()) {
4131 return false;
4132 }
4133 return getPermittedSubclasses() != null;
4134 }
4135
4136 private native Class<?>[] getPermittedSubclasses0();
4137
4138 /*
4139 * Return the class's major and minor class file version packed into an int.
4140 * The high order 16 bits contain the class's minor version. The low order
4141 * 16 bits contain the class's major version.
4142 *
4143 * If the class is an array type then the class file version of its element
4144 * type is returned. If the class is a primitive type then the latest class
4145 * file major version is returned and zero is returned for the minor version.
4146 */
4147 int getClassFileVersion() {
4148 Class<?> c = isArray() ? elementType() : this;
4149 return c.getClassFileVersion0();
4150 }
4151
4152 private native int getClassFileVersion0();
4153
4154 /**
4155 * Return the access flags as they were in the class's bytecode, including
4156 * the original setting of ACC_SUPER.
4157 *
4158 * If this {@code Class} object represents a primitive type or
4159 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
4160 * {@code FINAL}.
4161 * If this {@code Class} object represents an array type, return 0.
4162 */
4163 int getClassFileAccessFlags() {
4164 return classFileAccessFlags;
4165 }
4166
4167 // Validates the length of the class name and throws an exception if it exceeds the maximum allowed length.
4168 private static void validateClassNameLength(String name) throws ClassNotFoundException {
4169 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
4170 throw new ClassNotFoundException(
4171 "Class name length exceeds limit of "
4172 + ModifiedUtf.CONSTANT_POOL_UTF8_MAX_BYTES
4173 + ": " + name.substring(0,256) + "...");
4174 }
4175 }
4176
4177 // Support for "OLD" CDS workflow -- {
4178 private static final int RD_PUBLIC_METHODS = (1 << 0);
4179 private static final int RD_PUBLIC_FIELDS = (1 << 1);
4180 private static final int RD_DECLARED_CTORS = (1 << 2);
4181 private static final int RD_PUBLIC_CTORS = (1 << 3);
4182 private static final int RD_DECLARED_METHODS = (1 << 4);
4183 private static final int RD_DECLARED_PUBLIC_METHODS = (1 << 5);
4184 private static final int RD_DECLARED_FIELDS = (1 << 6);
4185 private static final int RD_DECLARED_PUBLIC_FIELDS = (1 << 7);
4186 private static final int RD_DECLARED_INTERFACES = (1 << 8);
4187 private static final int RD_DECLARED_SIMPLE_NAME = (1 << 9);
4188 private static final int RD_DECLARED_CANONICAL_NAME = (1 << 10);
4189 private static final int CLS_NAME = (1 << 10);
4190
4191
4192 private int encodeReflectionData() {
4193 int flags = CLS_NAME;
4194 if (reflectionData != null) {
4195 flags = (reflectionData.publicMethods != null ? RD_PUBLIC_METHODS : 0) |
4196 (reflectionData.publicFields != null ? RD_PUBLIC_FIELDS : 0) |
4197 (reflectionData.declaredConstructors != null ? RD_DECLARED_CTORS : 0) |
4198 (reflectionData.publicConstructors != null ? RD_PUBLIC_CTORS : 0) |
4199 (reflectionData.declaredMethods != null ? RD_DECLARED_METHODS : 0) |
4200 (reflectionData.declaredPublicMethods != null ? RD_DECLARED_PUBLIC_METHODS : 0) |
4201 (reflectionData.declaredFields != null ? RD_DECLARED_FIELDS : 0) |
4202 (reflectionData.declaredPublicFields != null ? RD_DECLARED_PUBLIC_FIELDS : 0) |
4203 (reflectionData.interfaces != null ? RD_DECLARED_INTERFACES : 0) |
4204 (reflectionData.simpleName != null ? RD_DECLARED_SIMPLE_NAME : 0) |
4205 (reflectionData.canonicalName != null ? RD_DECLARED_CANONICAL_NAME : 0);
4206 }
4207 return flags;
4208 }
4209 private void generateReflectionData(int flags) {
4210 if ((flags & CLS_NAME ) != 0) { getName(); } // String name
4211 if ((flags & RD_PUBLIC_METHODS ) != 0) { privateGetPublicMethods(); } // Method[] publicMethods;
4212 if ((flags & RD_PUBLIC_FIELDS ) != 0) { privateGetPublicFields(); } // Field[] publicFields;
4213 if ((flags & RD_DECLARED_CTORS ) != 0) { privateGetDeclaredConstructors(false); } // Constructor<T>[] declaredConstructors;
4214 if ((flags & RD_PUBLIC_CTORS ) != 0) { privateGetDeclaredConstructors(true); } // Constructor<T>[] publicConstructors;
4215 if ((flags & RD_DECLARED_METHODS ) != 0) { privateGetDeclaredMethods(false); } // Method[] declaredMethods;
4216 if ((flags & RD_DECLARED_PUBLIC_METHODS) != 0) { privateGetDeclaredMethods(true); } // Method[] declaredPublicMethods;
4217 if ((flags & RD_DECLARED_FIELDS ) != 0) { privateGetDeclaredFields(false); } // Field[] declaredFields;
4218 if ((flags & RD_DECLARED_PUBLIC_FIELDS ) != 0) { privateGetDeclaredFields(true); } // Field[] declaredPublicFields;
4219 if ((flags & RD_DECLARED_INTERFACES ) != 0) { getInterfaces(false); } // Class<?>[] interfaces;
4220 if ((flags & RD_DECLARED_SIMPLE_NAME ) != 0) { getSimpleName(); } // String simpleName;
4221 if ((flags & RD_DECLARED_CANONICAL_NAME) != 0) { getCanonicalName(); } // String canonicalName;
4222 }
4223
4224 // -- }
4225 }