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.Wrapper;
88 import sun.reflect.generics.factory.CoreReflectionFactory;
89 import sun.reflect.generics.factory.GenericsFactory;
90 import sun.reflect.generics.repository.ClassRepository;
91 import sun.reflect.generics.repository.MethodRepository;
92 import sun.reflect.generics.repository.ConstructorRepository;
93 import sun.reflect.generics.scope.ClassScope;
94 import sun.reflect.annotation.*;
95
96 /**
97 * Instances of the class {@code Class} represent classes and
98 * interfaces in a running Java application. An enum class and a record
99 * class are kinds of class; an annotation interface is a kind of
100 * interface. Every array also belongs to a class that is reflected as
101 * a {@code Class} object that is shared by all arrays with the same
102 * element type and number of dimensions. The primitive Java types
103 * ({@code boolean}, {@code byte}, {@code char}, {@code short}, {@code
104 * int}, {@code long}, {@code float}, and {@code double}), and the
105 * keyword {@code void} are also represented as {@code Class} objects.
106 *
107 * <p> {@code Class} has no public constructor. Instead a {@code Class}
108 * object is constructed automatically by the Java Virtual Machine when
109 * a class is derived from the bytes of a {@code class} file through
110 * the invocation of one of the following methods:
111 * <ul>
112 * <li> {@link ClassLoader#defineClass(String, byte[], int, int) ClassLoader::defineClass}
113 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
114 * java.lang.invoke.MethodHandles.Lookup::defineClass}
115 * <li> {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
116 * java.lang.invoke.MethodHandles.Lookup::defineHiddenClass}
117 * </ul>
118 *
119 * <p> The methods of class {@code Class} expose many characteristics of a
120 * class or interface. Most characteristics are derived from the {@code class}
121 * file that the class loader passed to the Java Virtual Machine or
122 * from the {@code class} file passed to {@code Lookup::defineClass}
123 * or {@code Lookup::defineHiddenClass}.
124 * A few characteristics are determined by the class loading environment
125 * at run time, such as the module returned by {@link #getModule() getModule()}.
126 *
127 * <p> The following example uses a {@code Class} object to print the
128 * class name of an object:
129 *
130 * {@snippet lang="java" :
131 * void printClassName(Object obj) {
132 * System.out.println("The class of " + obj +
133 * " is " + obj.getClass().getName());
134 * }}
135 *
136 * It is also possible to get the {@code Class} object for a named
137 * class or interface (or for {@code void}) using a <dfn>class literal</dfn>
138 * (JLS {@jls 15.8.2}).
139 * For example:
140 *
141 * {@snippet lang="java" :
142 * System.out.println("The name of class Foo is: " + Foo.class.getName()); // @highlight substring="Foo.class"
143 * }
144 *
145 * <p> Some methods of class {@code Class} expose whether the declaration of
146 * a class or interface in Java source code was <em>enclosed</em> within
147 * another declaration. Other methods describe how a class or interface
148 * is situated in a <dfn>{@index "nest"}</dfn>. A nest is a set of
149 * classes and interfaces, in the same run-time package, that
150 * allow mutual access to their {@code private} members.
151 * The classes and interfaces are known as <dfn>{@index "nestmates"}</dfn>
152 * (JVMS {@jvms 4.7.29}).
153 * One nestmate acts as the
154 * <dfn>nest host</dfn> (JVMS {@jvms 4.7.28}), and enumerates the other nestmates which
155 * belong to the nest; each of them in turn records it as the nest host.
156 * The classes and interfaces which belong to a nest, including its host, are
157 * determined when
158 * {@code class} files are generated, for example, a Java compiler
159 * will typically record a top-level class as the host of a nest where the
160 * other members are the classes and interfaces whose declarations are
161 * enclosed within the top-level class declaration.
162 *
163 * <h2><a id=hiddenClasses>Hidden Classes</a></h2>
164 * A class or interface created by the invocation of
165 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
166 * Lookup::defineHiddenClass} is a {@linkplain Class#isHidden() <dfn>hidden</dfn>}
167 * class or interface.
168 * All kinds of class, including enum classes and record classes, may be
169 * hidden classes; all kinds of interface, including annotation interfaces,
170 * may be hidden interfaces.
171 *
172 * The {@linkplain #getName() name of a hidden class or interface} is
173 * not a {@linkplain ClassLoader##binary-name binary name},
174 * which means the following:
175 * <ul>
176 * <li>A hidden class or interface cannot be referenced by the constant pools
177 * of other classes and interfaces.
178 * <li>A hidden class or interface cannot be described in
179 * {@linkplain java.lang.constant.ConstantDesc <em>nominal form</em>} by
180 * {@link #describeConstable() Class::describeConstable},
181 * {@link ClassDesc#of(String) ClassDesc::of}, or
182 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}.
183 * <li>A hidden class or interface cannot be discovered by {@link #forName Class::forName}
184 * or {@link ClassLoader#loadClass(String, boolean) ClassLoader::loadClass}.
185 * </ul>
186 *
187 * A hidden class or interface is never an array class, but may be
188 * the element type of an array. In all other respects, the fact that
189 * a class or interface is hidden has no bearing on the characteristics
190 * exposed by the methods of class {@code Class}.
191 *
192 * <h2><a id=implicitClasses>Implicitly Declared Classes</a></h2>
193 *
194 * Conventionally, a Java compiler, starting from a source file for an
195 * implicitly declared class, say {@code HelloWorld.java}, creates a
196 * similarly-named {@code class} file, {@code HelloWorld.class}, where
197 * the class stored in that {@code class} file is named {@code
198 * "HelloWorld"}, matching the base names of the source and {@code
199 * class} files.
200 *
201 * For the {@code Class} object of an implicitly declared class {@code
202 * HelloWorld}, the methods to get the {@linkplain #getName name} and
203 * {@linkplain #getTypeName type name} return results
204 * equal to {@code "HelloWorld"}. The {@linkplain #getSimpleName
205 * simple name} of such an implicitly declared class is {@code "HelloWorld"} and
206 * the {@linkplain #getCanonicalName canonical name} is {@code "HelloWorld"}.
207 *
208 * @param <T> the type of the class modeled by this {@code Class}
209 * object. For example, the type of {@code String.class} is {@code
210 * Class<String>}. Use {@code Class<?>} if the class being modeled is
211 * unknown.
212 *
213 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
214 * @since 1.0
215 */
216 @AOTSafeClassInitializer
217 public final class Class<T> implements java.io.Serializable,
218 GenericDeclaration,
219 Type,
220 AnnotatedElement,
221 TypeDescriptor.OfField<Class<?>>,
222 Constable {
223 private static final int ANNOTATION= 0x00002000;
224 private static final int ENUM = 0x00004000;
225 private static final int SYNTHETIC = 0x00001000;
226
227 private static native void registerNatives();
228 static {
229 runtimeSetup();
230 }
231
232 /// No significant static final fields; [#resetArchivedStates()] handles
233 /// prevents storing [#reflectionFactory] into AOT image.
234 @AOTRuntimeSetup
235 private static void runtimeSetup() {
236 registerNatives();
237 }
238
239 /*
240 * Private constructor. Only the Java Virtual Machine creates Class objects.
241 * This constructor is not used and prevents the default constructor being
242 * generated.
243 */
244 private Class(ClassLoader loader, Class<?> arrayComponentType, char mods, ProtectionDomain pd, boolean isPrim, char flags) {
245 // Initialize final field for classLoader. The initialization value of non-null
246 // prevents future JIT optimizations from assuming this final field is null.
247 // The following assignments are done directly by the VM without calling this constructor.
248 classLoader = loader;
249 componentType = arrayComponentType;
250 modifiers = mods;
251 protectionDomain = pd;
252 primitive = isPrim;
253 classFileAccessFlags = flags;
254 }
255
256 /**
257 * Converts the object to a string. The string representation is the
258 * string "class" or "interface", followed by a space, and then by the
259 * name of the class in the format returned by {@code getName}.
260 * If this {@code Class} object represents a primitive type,
261 * this method returns the name of the primitive type. If
262 * this {@code Class} object represents void this method returns
263 * "void". If this {@code Class} object represents an array type,
264 * this method returns "class " followed by {@code getName}.
265 *
266 * @return a string representation of this {@code Class} object.
267 */
268 public String toString() {
269 String kind = isInterface() ? "interface " : isPrimitive() ? "" : "class ";
270 return kind.concat(getName());
271 }
272
273 /**
274 * Returns a string describing this {@code Class}, including
275 * information about modifiers, {@link #isSealed() sealed}/{@code
276 * non-sealed} status, and type parameters.
277 *
278 * The string is formatted as a list of type modifiers, if any,
279 * followed by the kind of type (empty string for primitive types
280 * and {@code class}, {@code enum}, {@code interface},
281 * {@code @interface}, or {@code record} as appropriate), followed
282 * by the type's name, followed by an angle-bracketed
283 * comma-separated list of the type's type parameters, if any,
284 * including informative bounds on the type parameters, if any.
285 *
286 * A space is used to separate modifiers from one another and to
287 * separate any modifiers from the kind of type. The modifiers
288 * occur in canonical order. If there are no type parameters, the
289 * type parameter list is elided.
290 *
291 * For an array type, the string starts with the type name,
292 * followed by an angle-bracketed comma-separated list of the
293 * type's type parameters, if any, followed by a sequence of
294 * {@code []} characters, one set of brackets per dimension of
295 * the array.
296 *
297 * <p>Note that since information about the runtime representation
298 * of a type is being generated, modifiers not present on the
299 * originating source code or illegal on the originating source
300 * code may be present.
301 *
302 * @return a string describing this {@code Class}, including
303 * information about modifiers and type parameters
304 *
305 * @since 1.8
306 */
307 public String toGenericString() {
308 if (isPrimitive()) {
309 return toString();
310 } else {
311 StringBuilder sb = new StringBuilder();
312 Class<?> component = this;
313 int arrayDepth = 0;
314
315 if (isArray()) {
316 do {
317 arrayDepth++;
318 component = component.getComponentType();
319 } while (component.isArray());
320 sb.append(component.getName());
321 } else {
322 // Class modifiers are a superset of interface modifiers
323 int modifiers = getModifiers() & Modifier.classModifiers();
324 if (modifiers != 0) {
325 sb.append(Modifier.toString(modifiers));
326 sb.append(' ');
327 }
328
329 // A class cannot be strictfp and sealed/non-sealed so
330 // it is sufficient to check for sealed-ness after all
331 // modifiers are printed.
332 addSealingInfo(modifiers, sb);
333
334 if (isAnnotation()) {
335 sb.append('@');
336 }
337 if (isInterface()) { // Note: all annotation interfaces are interfaces
338 sb.append("interface");
339 } else {
340 if (isEnum())
341 sb.append("enum");
342 else if (isRecord())
343 sb.append("record");
344 else
345 sb.append("class");
346 }
347 sb.append(' ');
348 sb.append(getName());
349 }
350
351 TypeVariable<?>[] typeparms = component.getTypeParameters();
352 if (typeparms.length > 0) {
353 sb.append(Arrays.stream(typeparms)
354 .map(Class::typeVarBounds)
355 .collect(Collectors.joining(",", "<", ">")));
356 }
357
358 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
359
360 return sb.toString();
361 }
362 }
363
364 private void addSealingInfo(int modifiers, StringBuilder sb) {
365 // A class can be final XOR sealed XOR non-sealed.
366 if (Modifier.isFinal(modifiers)) {
367 return; // no-op
368 } else {
369 if (isSealed()) {
370 sb.append("sealed ");
371 return;
372 } else {
373 // Check for sealed ancestor, which implies this class
374 // is non-sealed.
375 if (hasSealedAncestor(this)) {
376 sb.append("non-sealed ");
377 }
378 }
379 }
380 }
381
382 private boolean hasSealedAncestor(Class<?> clazz) {
383 // From JLS 8.1.1.2:
384 // "It is a compile-time error if a class has a sealed direct
385 // superclass or a sealed direct superinterface, and is not
386 // declared final, sealed, or non-sealed either explicitly or
387 // implicitly.
388 // Thus, an effect of the sealed keyword is to force all
389 // direct subclasses to explicitly declare whether they are
390 // final, sealed, or non-sealed. This avoids accidentally
391 // exposing a sealed class hierarchy to unwanted subclassing."
392
393 // Therefore, will just check direct superclass and
394 // superinterfaces.
395 var superclass = clazz.getSuperclass();
396 if (superclass != null && superclass.isSealed()) {
397 return true;
398 }
399 for (var superinterface : clazz.getInterfaces()) {
400 if (superinterface.isSealed()) {
401 return true;
402 }
403 }
404 return false;
405 }
406
407 static String typeVarBounds(TypeVariable<?> typeVar) {
408 Type[] bounds = typeVar.getBounds();
409 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
410 return typeVar.getName();
411 } else {
412 return typeVar.getName() + " extends " +
413 Arrays.stream(bounds)
414 .map(Type::getTypeName)
415 .collect(Collectors.joining(" & "));
416 }
417 }
418
419 /**
420 * Returns the {@code Class} object associated with the class or
421 * interface with the given string name. Invoking this method is
422 * equivalent to:
423 *
424 * {@snippet lang="java" :
425 * Class.forName(className, true, currentLoader)
426 * }
427 *
428 * where {@code currentLoader} denotes the defining class loader of
429 * the current class.
430 *
431 * <p> For example, the following code fragment returns the
432 * runtime {@code Class} object for the class named
433 * {@code java.lang.Thread}:
434 *
435 * {@snippet lang="java" :
436 * Class<?> t = Class.forName("java.lang.Thread");
437 * }
438 * <p>
439 * A call to {@code forName("X")} causes the class named
440 * {@code X} to be initialized.
441 *
442 * <p>
443 * In cases where this method is called from a context where there is no
444 * caller frame on the stack (e.g. when called directly from a JNI
445 * attached thread), the system class loader is used.
446 *
447 * @param className the {@linkplain ClassLoader##binary-name binary name}
448 * of the class or the string representing an array type
449 * @return the {@code Class} object for the class with the
450 * specified name.
451 * @throws LinkageError if the linkage fails
452 * @throws ExceptionInInitializerError if the initialization provoked
453 * by this method fails
454 * @throws ClassNotFoundException if the class cannot be located
455 *
456 * @jls 12.2 Loading of Classes and Interfaces
457 * @jls 12.3 Linking of Classes and Interfaces
458 * @jls 12.4 Initialization of Classes and Interfaces
459 */
460 @CallerSensitive
461 public static Class<?> forName(String className)
462 throws ClassNotFoundException {
463 Class<?> caller = Reflection.getCallerClass();
464 return forName(className, caller);
465 }
466
467 // Caller-sensitive adapter method for reflective invocation
468 @CallerSensitiveAdapter
469 private static Class<?> forName(String className, Class<?> caller)
470 throws ClassNotFoundException {
471 validateClassNameLength(className);
472 ClassLoader loader = (caller == null) ? ClassLoader.getSystemClassLoader()
473 : ClassLoader.getClassLoader(caller);
474 if (loader instanceof BuiltinClassLoader bcl) {
475 if (bcl.usePositiveCache) {
476 Class<?> result = bcl.checkPositiveLookupCache(className);
477 if (result != null) {
478 // forName(String, Class) API will always initialize the class
479 Unsafe.getUnsafe().ensureClassInitialized(result);
480 return result;
481 }
482 }
483 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(className)) {
484 throw new ClassNotFoundException(className);
485 }
486 }
487 return forName0(className, true, loader, caller);
488 }
489
490 /**
491 * Returns the {@code Class} object associated with the class or
492 * interface with the given string name, using the given class loader.
493 * Given the {@linkplain ClassLoader##binary-name binary name} for a class or interface,
494 * this method attempts to locate and load the class or interface. The specified
495 * class loader is used to load the class or interface. If the parameter
496 * {@code loader} is {@code null}, the class is loaded through the bootstrap
497 * class loader. The class is initialized only if the
498 * {@code initialize} parameter is {@code true} and if it has
499 * not been initialized earlier.
500 *
501 * <p> This method cannot be used to obtain any of the {@code Class} objects
502 * representing primitive types or void, hidden classes or interfaces,
503 * or array classes whose element type is a hidden class or interface.
504 * If {@code name} denotes a primitive type or void, for example {@code I},
505 * an attempt will be made to locate a user-defined class in the unnamed package
506 * whose name is {@code I} instead.
507 * To obtain a {@code Class} object for a named primitive type
508 * such as {@code int} or {@code long} use {@link
509 * #forPrimitiveName(String)}.
510 *
511 * <p> To obtain the {@code Class} object associated with an array class,
512 * the name consists of one or more {@code '['} representing the depth
513 * of the array nesting, followed by the element type as encoded in
514 * {@linkplain ##nameFormat the table} specified in {@code Class.getName()}.
515 *
516 * <p> Examples:
517 * {@snippet lang="java" :
518 * Class<?> threadClass = Class.forName("java.lang.Thread", false, currentLoader);
519 * Class<?> stringArrayClass = Class.forName("[Ljava.lang.String;", false, currentLoader);
520 * Class<?> intArrayClass = Class.forName("[[[I", false, currentLoader); // Class of int[][][]
521 * Class<?> nestedClass = Class.forName("java.lang.Character$UnicodeBlock", false, currentLoader);
522 * Class<?> fooClass = Class.forName("Foo", true, currentLoader);
523 * }
524 *
525 * <p> A call to {@code getName()} on the {@code Class} object returned
526 * from {@code forName(}<i>N</i>{@code )} returns <i>N</i>.
527 *
528 * <p> A call to {@code forName("[L}<i>N</i>{@code ;")} causes the element type
529 * named <i>N</i> to be loaded but not initialized regardless of the value
530 * of the {@code initialize} parameter.
531 *
532 * @apiNote
533 * This method throws errors related to loading, linking or initializing
534 * as specified in Sections {@jls 12.2}, {@jls 12.3}, and {@jls 12.4} of
535 * <cite>The Java Language Specification</cite>.
536 * In addition, this method does not check whether the requested class
537 * is accessible to its caller.
538 *
539 * @param name the {@linkplain ClassLoader##binary-name binary name}
540 * of the class or the string representing an array class
541 *
542 * @param initialize if {@code true} the class will be initialized
543 * (which implies linking). See Section {@jls
544 * 12.4} of <cite>The Java Language
545 * Specification</cite>.
546 * @param loader class loader from which the class must be loaded
547 * @return class object representing the desired class
548 *
549 * @throws LinkageError if the linkage fails
550 * @throws ExceptionInInitializerError if the initialization provoked
551 * by this method fails
552 * @throws ClassNotFoundException if the class cannot be located by
553 * the specified class loader
554 *
555 * @see java.lang.Class#forName(String)
556 * @see java.lang.ClassLoader
557 *
558 * @jls 12.2 Loading of Classes and Interfaces
559 * @jls 12.3 Linking of Classes and Interfaces
560 * @jls 12.4 Initialization of Classes and Interfaces
561 * @jls 13.1 The Form of a Binary
562 * @since 1.2
563 */
564 public static Class<?> forName(String name, boolean initialize, ClassLoader loader)
565 throws ClassNotFoundException
566 {
567 validateClassNameLength(name);
568
569 if (loader instanceof BuiltinClassLoader bcl) {
570 if (bcl.usePositiveCache) {
571 Class<?> result = bcl.checkPositiveLookupCache(name);
572 if (result != null) {
573 if (initialize) {
574 Unsafe.getUnsafe().ensureClassInitialized(result);
575 }
576 return result;
577 }
578 }
579 if (bcl.useNegativeCache && bcl.checkNegativeLookupCache(name)) {
580 throw new ClassNotFoundException(name);
581 }
582 }
583
584 return forName0(name, initialize, loader, null);
585 }
586
587 /** Called after security check for system loader access checks have been made. */
588 private static native Class<?> forName0(String name, boolean initialize,
589 ClassLoader loader,
590 Class<?> caller)
591 throws ClassNotFoundException;
592
593
594 /**
595 * Returns the {@code Class} with the given {@linkplain ClassLoader##binary-name
596 * binary name} in the given module.
597 *
598 * <p> This method attempts to locate and load the class or interface.
599 * It does not link the class, and does not run the class initializer.
600 * If the class is not found, this method returns {@code null}. </p>
601 *
602 * <p> If the class loader of the given module defines other modules and
603 * the given name is a class defined in a different module, this method
604 * returns {@code null} after the class is loaded. </p>
605 *
606 * <p> This method does not check whether the requested class is
607 * accessible to its caller. </p>
608 *
609 * @apiNote
610 * This method does not support loading of array types, unlike
611 * {@link #forName(String, boolean, ClassLoader)}. The class name must be
612 * a binary name. This method returns {@code null} on failure rather than
613 * throwing a {@link ClassNotFoundException}, as is done by
614 * the {@link #forName(String, boolean, ClassLoader)} method.
615 *
616 * @param module A module
617 * @param name The {@linkplain ClassLoader##binary-name binary name}
618 * of the class
619 * @return {@code Class} object of the given name defined in the given module;
620 * {@code null} if not found.
621 *
622 * @throws NullPointerException if the given module or name is {@code null}
623 *
624 * @throws LinkageError if the linkage fails
625 *
626 * @jls 12.2 Loading of Classes and Interfaces
627 * @jls 12.3 Linking of Classes and Interfaces
628 * @since 9
629 */
630 public static Class<?> forName(Module module, String name) {
631 Objects.requireNonNull(module);
632 Objects.requireNonNull(name);
633 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
634 return null;
635 }
636
637 ClassLoader cl = module.getClassLoader();
638 if (cl != null) {
639 return cl.loadClass(module, name);
640 } else {
641 return BootLoader.loadClass(module, name);
642 }
643 }
644
645 /**
646 * {@return the {@code Class} object associated with the
647 * {@linkplain #isPrimitive() primitive type} of the given name}
648 * If the argument is not the name of a primitive type, {@code
649 * null} is returned.
650 *
651 * @param primitiveName the name of the primitive type to find
652 *
653 * @throws NullPointerException if the argument is {@code null}
654 *
655 * @jls 4.2 Primitive Types and Values
656 * @jls 15.8.2 Class Literals
657 * @since 22
658 */
659 public static Class<?> forPrimitiveName(String primitiveName) {
660 return switch(primitiveName) {
661 // Integral types
662 case "int" -> int.class;
663 case "long" -> long.class;
664 case "short" -> short.class;
665 case "char" -> char.class;
666 case "byte" -> byte.class;
667
668 // Floating-point types
669 case "float" -> float.class;
670 case "double" -> double.class;
671
672 // Other types
673 case "boolean" -> boolean.class;
674 case "void" -> void.class;
675
676 default -> null;
677 };
678 }
679
680 /**
681 * Creates a new instance of the class represented by this {@code Class}
682 * object. The class is instantiated as if by a {@code new}
683 * expression with an empty argument list. The class is initialized if it
684 * has not already been initialized.
685 *
686 * @deprecated This method propagates any exception thrown by the
687 * nullary constructor, including a checked exception. Use of
688 * this method effectively bypasses the compile-time exception
689 * checking that would otherwise be performed by the compiler.
690 * The {@link
691 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
692 * Constructor.newInstance} method avoids this problem by wrapping
693 * any exception thrown by the constructor in a (checked) {@link
694 * java.lang.reflect.InvocationTargetException}.
695 *
696 * <p>The call
697 *
698 * {@snippet lang="java" :
699 * clazz.newInstance()
700 * }
701 *
702 * can be replaced by
703 *
704 * {@snippet lang="java" :
705 * clazz.getDeclaredConstructor().newInstance()
706 * }
707 *
708 * The latter sequence of calls is inferred to be able to throw
709 * the additional exception types {@link
710 * InvocationTargetException} and {@link
711 * NoSuchMethodException}. Both of these exception types are
712 * subclasses of {@link ReflectiveOperationException}.
713 *
714 * @return a newly allocated instance of the class represented by this
715 * object.
716 * @throws IllegalAccessException if the class or its nullary
717 * constructor is not accessible.
718 * @throws InstantiationException
719 * if this {@code Class} represents an abstract class,
720 * an interface, an array class, a primitive type, or void;
721 * or if the class has no nullary constructor;
722 * or if the instantiation fails for some other reason.
723 * @throws ExceptionInInitializerError if the initialization
724 * provoked by this method fails.
725 */
726 @CallerSensitive
727 @Deprecated(since="9")
728 public T newInstance()
729 throws InstantiationException, IllegalAccessException
730 {
731 // Constructor lookup
732 Constructor<T> tmpConstructor = cachedConstructor;
733 if (tmpConstructor == null) {
734 if (this == Class.class) {
735 throw new IllegalAccessException(
736 "Can not call newInstance() on the Class for java.lang.Class"
737 );
738 }
739 try {
740 Class<?>[] empty = {};
741 final Constructor<T> c = getReflectionFactory().copyConstructor(
742 getConstructor0(empty, Member.DECLARED));
743 // Disable accessibility checks on the constructor
744 // access check is done with the true caller
745 c.setAccessible(true);
746 cachedConstructor = tmpConstructor = c;
747 } catch (NoSuchMethodException e) {
748 throw (InstantiationException)
749 new InstantiationException(getName()).initCause(e);
750 }
751 }
752
753 try {
754 Class<?> caller = Reflection.getCallerClass();
755 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
756 } catch (InvocationTargetException e) {
757 Unsafe.getUnsafe().throwException(e.getTargetException());
758 // Not reached
759 return null;
760 }
761 }
762
763 private transient volatile Constructor<T> cachedConstructor;
764
765 /**
766 * Determines if the specified {@code Object} is assignment-compatible
767 * with the object represented by this {@code Class}. This method is
768 * the dynamic equivalent of the Java language {@code instanceof}
769 * operator. The method returns {@code true} if the specified
770 * {@code Object} argument is non-null and can be cast to the
771 * reference type represented by this {@code Class} object without
772 * raising a {@code ClassCastException.} It returns {@code false}
773 * otherwise.
774 *
775 * <p> Specifically, if this {@code Class} object represents a
776 * declared class, this method returns {@code true} if the specified
777 * {@code Object} argument is an instance of the represented class (or
778 * of any of its subclasses); it returns {@code false} otherwise. If
779 * this {@code Class} object represents an array class, this method
780 * returns {@code true} if the specified {@code Object} argument
781 * can be converted to an object of the array class by an identity
782 * conversion or by a widening reference conversion; it returns
783 * {@code false} otherwise. If this {@code Class} object
784 * represents an interface, this method returns {@code true} if the
785 * class or any superclass of the specified {@code Object} argument
786 * implements this interface; it returns {@code false} otherwise. If
787 * this {@code Class} object represents a primitive type, this method
788 * returns {@code false}.
789 *
790 * @param obj the object to check
791 * @return true if {@code obj} is an instance of this class
792 *
793 * @since 1.1
794 */
795 @IntrinsicCandidate
796 public native boolean isInstance(Object obj);
797
798
799 /**
800 * Determines if the class or interface represented by this
801 * {@code Class} object is either the same as, or is a superclass or
802 * superinterface of, the class or interface represented by the specified
803 * {@code Class} parameter. It returns {@code true} if so;
804 * otherwise it returns {@code false}. If this {@code Class}
805 * object represents a primitive type, this method returns
806 * {@code true} if the specified {@code Class} parameter is
807 * exactly this {@code Class} object; otherwise it returns
808 * {@code false}.
809 *
810 * <p> Specifically, this method tests whether the type represented by the
811 * specified {@code Class} parameter can be converted to the type
812 * represented by this {@code Class} object via an identity conversion
813 * or via a widening reference conversion. See <cite>The Java Language
814 * Specification</cite>, sections {@jls 5.1.1} and {@jls 5.1.4},
815 * for details.
816 *
817 * @param cls the {@code Class} object to be checked
818 * @return the {@code boolean} value indicating whether objects of the
819 * type {@code cls} can be assigned to objects of this class
820 * @throws NullPointerException if the specified Class parameter is
821 * null.
822 * @since 1.1
823 */
824 @IntrinsicCandidate
825 public native boolean isAssignableFrom(Class<?> cls);
826
827
828 /**
829 * Determines if this {@code Class} object represents an
830 * interface type.
831 *
832 * @return {@code true} if this {@code Class} object represents an interface;
833 * {@code false} otherwise.
834 */
835 public boolean isInterface() {
836 return Modifier.isInterface(modifiers);
837 }
838
839
840 /**
841 * Determines if this {@code Class} object represents an array class.
842 *
843 * @return {@code true} if this {@code Class} object represents an array class;
844 * {@code false} otherwise.
845 * @since 1.1
846 */
847 public boolean isArray() {
848 return componentType != null;
849 }
850
851
852 /**
853 * Determines if this {@code Class} object represents a primitive
854 * type or void.
855 *
856 * <p> There are nine predefined {@code Class} objects to
857 * represent the eight primitive types and void. These are
858 * created by the Java Virtual Machine, and have the same
859 * {@linkplain #getName() names} as the primitive types that they
860 * represent, namely {@code boolean}, {@code byte}, {@code char},
861 * {@code short}, {@code int}, {@code long}, {@code float}, and
862 * {@code double}.
863 *
864 * <p>No other class objects are considered primitive.
865 *
866 * @apiNote
867 * A {@code Class} object represented by a primitive type can be
868 * accessed via the {@code TYPE} public static final variables
869 * defined in the primitive wrapper classes such as {@link
870 * java.lang.Integer#TYPE Integer.TYPE}. In the Java programming
871 * language, the objects may be referred to by a class literal
872 * expression such as {@code int.class}. The {@code Class} object
873 * for void can be expressed as {@code void.class} or {@link
874 * java.lang.Void#TYPE Void.TYPE}.
875 *
876 * @return true if and only if this class represents a primitive type
877 *
878 * @see java.lang.Boolean#TYPE
879 * @see java.lang.Character#TYPE
880 * @see java.lang.Byte#TYPE
881 * @see java.lang.Short#TYPE
882 * @see java.lang.Integer#TYPE
883 * @see java.lang.Long#TYPE
884 * @see java.lang.Float#TYPE
885 * @see java.lang.Double#TYPE
886 * @see java.lang.Void#TYPE
887 * @since 1.1
888 * @jls 15.8.2 Class Literals
889 */
890 public boolean isPrimitive() {
891 return primitive;
892 }
893
894 /**
895 * Returns true if this {@code Class} object represents an annotation
896 * interface. Note that if this method returns true, {@link #isInterface()}
897 * would also return true, as all annotation interfaces are also interfaces.
898 *
899 * @return {@code true} if this {@code Class} object represents an annotation
900 * interface; {@code false} otherwise
901 * @since 1.5
902 */
903 public boolean isAnnotation() {
904 return (getModifiers() & ANNOTATION) != 0;
905 }
906
907 /**
908 *{@return {@code true} if and only if this class has the synthetic modifier
909 * bit set}
910 *
911 * @jls 13.1 The Form of a Binary
912 * @jvms 4.1 The {@code ClassFile} Structure
913 * @see <a
914 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
915 * programming language and JVM modeling in core reflection</a>
916 * @since 1.5
917 */
918 public boolean isSynthetic() {
919 return (getModifiers() & SYNTHETIC) != 0;
920 }
921
922 /**
923 * Returns the name of the entity (class, interface, array class,
924 * primitive type, or void) represented by this {@code Class} object.
925 *
926 * <p> If this {@code Class} object represents a class or interface,
927 * not an array class, then:
928 * <ul>
929 * <li> If the class or interface is not {@linkplain #isHidden() hidden},
930 * then the {@linkplain ClassLoader##binary-name binary name}
931 * of the class or interface is returned.
932 * <li> If the class or interface is hidden, then the result is a string
933 * of the form: {@code N + '/' + <suffix>}
934 * where {@code N} is the {@linkplain ClassLoader##binary-name binary name}
935 * indicated by the {@code class} file passed to
936 * {@link java.lang.invoke.MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
937 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
938 * </ul>
939 *
940 * <p> If this {@code Class} object represents an array class, then
941 * the result is a string consisting of one or more '{@code [}' characters
942 * representing the depth of the array nesting, followed by the element
943 * type as encoded using the following table:
944 *
945 * <blockquote><table class="striped" id="nameFormat">
946 * <caption style="display:none">Element types and encodings</caption>
947 * <thead>
948 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
949 * </thead>
950 * <tbody style="text-align:left">
951 * <tr><th scope="row"> {@code boolean} <td style="text-align:center"> {@code Z}
952 * <tr><th scope="row"> {@code byte} <td style="text-align:center"> {@code B}
953 * <tr><th scope="row"> {@code char} <td style="text-align:center"> {@code C}
954 * <tr><th scope="row"> class or interface with {@linkplain ClassLoader##binary-name binary name} <i>N</i>
955 * <td style="text-align:center"> {@code L}<em>N</em>{@code ;}
956 * <tr><th scope="row"> {@code double} <td style="text-align:center"> {@code D}
957 * <tr><th scope="row"> {@code float} <td style="text-align:center"> {@code F}
958 * <tr><th scope="row"> {@code int} <td style="text-align:center"> {@code I}
959 * <tr><th scope="row"> {@code long} <td style="text-align:center"> {@code J}
960 * <tr><th scope="row"> {@code short} <td style="text-align:center"> {@code S}
961 * </tbody>
962 * </table></blockquote>
963 *
964 * <p> If this {@code Class} object represents a primitive type or {@code void},
965 * then the result is a string with the same spelling as the Java language
966 * keyword which corresponds to the primitive type or {@code void}.
967 *
968 * <p> Examples:
969 * <blockquote><pre>
970 * String.class.getName()
971 * returns "java.lang.String"
972 * Character.UnicodeBlock.class.getName()
973 * returns "java.lang.Character$UnicodeBlock"
974 * byte.class.getName()
975 * returns "byte"
976 * (new Object[3]).getClass().getName()
977 * returns "[Ljava.lang.Object;"
978 * (new int[3][4][5][6][7][8][9]).getClass().getName()
979 * returns "[[[[[[[I"
980 * </pre></blockquote>
981 *
982 * @apiNote
983 * Distinct class objects can have the same name but different class loaders.
984 *
985 * @return the name of the class, interface, or other entity
986 * represented by this {@code Class} object.
987 * @jls 13.1 The Form of a Binary
988 */
989 public String getName() {
990 String name = this.name;
991 return name != null ? name : initClassName();
992 }
993
994 // Cache the name to reduce the number of calls into the VM.
995 // This field would be set by VM itself during initClassName call.
996 private transient String name;
997 private native String initClassName();
998
999 /**
1000 * Returns the class loader for the class. Some implementations may use
1001 * null to represent the bootstrap class loader. This method will return
1002 * null in such implementations if this class was loaded by the bootstrap
1003 * class loader.
1004 *
1005 * <p>If this {@code Class} object
1006 * represents a primitive type or void, null is returned.
1007 *
1008 * @return the class loader that loaded the class or interface
1009 * represented by this {@code Class} object.
1010 * @see java.lang.ClassLoader
1011 */
1012 public ClassLoader getClassLoader() {
1013 return classLoader;
1014 }
1015
1016 // Package-private to allow ClassLoader access
1017 ClassLoader getClassLoader0() { return classLoader; }
1018
1019 /**
1020 * Returns the module that this class or interface is a member of.
1021 *
1022 * If this class represents an array type then this method returns the
1023 * {@code Module} for the element type. If this class represents a
1024 * primitive type or void, then the {@code Module} object for the
1025 * {@code java.base} module is returned.
1026 *
1027 * If this class is in an unnamed module then the {@linkplain
1028 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
1029 * loader for this class is returned.
1030 *
1031 * @return the module that this class or interface is a member of
1032 *
1033 * @since 9
1034 */
1035 public Module getModule() {
1036 return module;
1037 }
1038
1039 // set by VM
1040 @Stable
1041 private transient Module module;
1042
1043 // Initialized in JVM not by private constructor
1044 // This field is filtered from reflection access, i.e. getDeclaredField
1045 // will throw NoSuchFieldException
1046 private final ClassLoader classLoader;
1047
1048 private transient Object classData; // Set by VM
1049 private transient Object[] signers; // Read by VM, mutable
1050 private final transient char modifiers; // Set by the VM
1051 private final transient char classFileAccessFlags; // Set by the VM
1052 private final transient boolean primitive; // Set by the VM if the Class is a primitive type.
1053
1054 // package-private
1055 Object getClassData() {
1056 return classData;
1057 }
1058
1059 /**
1060 * Returns an array of {@code TypeVariable} objects that represent the
1061 * type variables declared by the generic declaration represented by this
1062 * {@code GenericDeclaration} object, in declaration order. Returns an
1063 * array of length 0 if the underlying generic declaration declares no type
1064 * variables.
1065 *
1066 * @return an array of {@code TypeVariable} objects that represent
1067 * the type variables declared by this generic declaration
1068 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1069 * signature of this generic declaration does not conform to
1070 * the format specified in section {@jvms 4.7.9} of
1071 * <cite>The Java Virtual Machine Specification</cite>
1072 * @since 1.5
1073 */
1074 @SuppressWarnings("unchecked")
1075 public TypeVariable<Class<T>>[] getTypeParameters() {
1076 ClassRepository info = getGenericInfo();
1077 if (info != null)
1078 return (TypeVariable<Class<T>>[])info.getTypeParameters();
1079 else
1080 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
1081 }
1082
1083
1084 /**
1085 * Returns the {@code Class} representing the direct superclass of the
1086 * entity (class, interface, primitive type or void) represented by
1087 * this {@code Class}. If this {@code Class} represents either the
1088 * {@code Object} class, an interface, a primitive type, or void, then
1089 * null is returned. If this {@code Class} object represents an array class
1090 * then the {@code Class} object representing the {@code Object} class is
1091 * returned.
1092 *
1093 * @return the direct superclass of the class represented by this {@code Class} object
1094 */
1095 @IntrinsicCandidate
1096 public native Class<? super T> getSuperclass();
1097
1098
1099 /**
1100 * Returns the {@code Type} representing the direct superclass of
1101 * the entity (class, interface, primitive type or void) represented by
1102 * this {@code Class} object.
1103 *
1104 * <p>If the superclass is a parameterized type, the {@code Type}
1105 * object returned must accurately reflect the actual type
1106 * arguments used in the source code. The parameterized type
1107 * representing the superclass is created if it had not been
1108 * created before. See the declaration of {@link
1109 * java.lang.reflect.ParameterizedType ParameterizedType} for the
1110 * semantics of the creation process for parameterized types. If
1111 * this {@code Class} object represents either the {@code Object}
1112 * class, an interface, a primitive type, or void, then null is
1113 * returned. If this {@code Class} object represents an array class
1114 * then the {@code Class} object representing the {@code Object} class is
1115 * returned.
1116 *
1117 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
1118 * class signature does not conform to the format specified in
1119 * section {@jvms 4.7.9} of <cite>The Java Virtual
1120 * Machine Specification</cite>
1121 * @throws TypeNotPresentException if the generic superclass
1122 * refers to a non-existent type declaration
1123 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
1124 * generic superclass refers to a parameterized type that cannot be
1125 * instantiated for any reason
1126 * @return the direct superclass of the class represented by this {@code Class} object
1127 * @since 1.5
1128 */
1129 public Type getGenericSuperclass() {
1130 ClassRepository info = getGenericInfo();
1131 if (info == null) {
1132 return getSuperclass();
1133 }
1134
1135 // Historical irregularity:
1136 // Generic signature marks interfaces with superclass = Object
1137 // but this API returns null for interfaces
1138 if (isInterface()) {
1139 return null;
1140 }
1141
1142 return info.getSuperclass();
1143 }
1144
1145 /**
1146 * Gets the package of this class.
1147 *
1148 * <p>If this class represents an array type, a primitive type or void,
1149 * this method returns {@code null}.
1150 *
1151 * @return the package of this class.
1152 */
1153 public Package getPackage() {
1154 if (isPrimitive() || isArray()) {
1155 return null;
1156 }
1157 ClassLoader cl = classLoader;
1158 return cl != null ? cl.definePackage(this)
1159 : BootLoader.definePackage(this);
1160 }
1161
1162 /**
1163 * Returns the fully qualified package name.
1164 *
1165 * <p> If this class is a top level class, then this method returns the fully
1166 * qualified name of the package that the class is a member of, or the
1167 * empty string if the class is in an unnamed package.
1168 *
1169 * <p> If this class is a member class, then this method is equivalent to
1170 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1171 * enclosing class}.
1172 *
1173 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1174 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1175 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1176 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1177 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1178 *
1179 * <p> If this class represents an array type then this method returns the
1180 * package name of the element type. If this class represents a primitive
1181 * type or void then the package name "{@code java.lang}" is returned.
1182 *
1183 * @return the fully qualified package name
1184 *
1185 * @since 9
1186 * @jls 6.7 Fully Qualified Names and Canonical Names
1187 */
1188 public String getPackageName() {
1189 String pn = this.packageName;
1190 if (pn == null) {
1191 Class<?> c = isArray() ? elementType() : this;
1192 if (c.isPrimitive()) {
1193 pn = "java.lang";
1194 } else {
1195 String cn = c.getName();
1196 int dot = cn.lastIndexOf('.');
1197 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1198 }
1199 this.packageName = pn;
1200 }
1201 return pn;
1202 }
1203
1204 // cached package name
1205 private transient String packageName;
1206
1207 /**
1208 * Returns the interfaces directly implemented by the class or interface
1209 * represented by this {@code Class} object.
1210 *
1211 * <p>If this {@code Class} object represents a class, the return value is an array
1212 * containing objects representing all interfaces directly implemented by
1213 * the class. The order of the interface objects in the array corresponds
1214 * to the order of the interface names in the {@code implements} clause of
1215 * the declaration of the class represented by this {@code Class} object. For example,
1216 * given the declaration:
1217 * <blockquote>
1218 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1219 * </blockquote>
1220 * suppose the value of {@code s} is an instance of
1221 * {@code Shimmer}; the value of the expression:
1222 * <blockquote>
1223 * {@code s.getClass().getInterfaces()[0]}
1224 * </blockquote>
1225 * is the {@code Class} object that represents interface
1226 * {@code FloorWax}; and the value of:
1227 * <blockquote>
1228 * {@code s.getClass().getInterfaces()[1]}
1229 * </blockquote>
1230 * is the {@code Class} object that represents interface
1231 * {@code DessertTopping}.
1232 *
1233 * <p>If this {@code Class} object represents an interface, the array contains objects
1234 * representing all interfaces directly extended by the interface. The
1235 * order of the interface objects in the array corresponds to the order of
1236 * the interface names in the {@code extends} clause of the declaration of
1237 * the interface represented by this {@code Class} object.
1238 *
1239 * <p>If this {@code Class} object represents a class or interface that implements no
1240 * interfaces, the method returns an array of length 0.
1241 *
1242 * <p>If this {@code Class} object represents a primitive type or void, the method
1243 * returns an array of length 0.
1244 *
1245 * <p>If this {@code Class} object represents an array type, the
1246 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1247 * returned in that order.
1248 *
1249 * @return an array of interfaces directly implemented by this class
1250 */
1251 public Class<?>[] getInterfaces() {
1252 // defensively copy before handing over to user code
1253 return getInterfaces(true);
1254 }
1255
1256 private Class<?>[] getInterfaces(boolean cloneArray) {
1257 ReflectionData<T> rd = reflectionData();
1258 Class<?>[] interfaces = rd.interfaces;
1259 if (interfaces == null) {
1260 interfaces = getInterfaces0();
1261 rd.interfaces = interfaces;
1262 }
1263 // defensively copy if requested
1264 return cloneArray ? interfaces.clone() : interfaces;
1265 }
1266
1267 private native Class<?>[] getInterfaces0();
1268
1269 /**
1270 * Returns the {@code Type}s representing the interfaces
1271 * directly implemented by the class or interface represented by
1272 * this {@code Class} object.
1273 *
1274 * <p>If a superinterface is a parameterized type, the
1275 * {@code Type} object returned for it must accurately reflect
1276 * the actual type arguments used in the source code. The
1277 * parameterized type representing each superinterface is created
1278 * if it had not been created before. See the declaration of
1279 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1280 * for the semantics of the creation process for parameterized
1281 * types.
1282 *
1283 * <p>If this {@code Class} object represents a class, the return value is an array
1284 * containing objects representing all interfaces directly implemented by
1285 * the class. The order of the interface objects in the array corresponds
1286 * to the order of the interface names in the {@code implements} clause of
1287 * the declaration of the class represented by this {@code Class} object.
1288 *
1289 * <p>If this {@code Class} object represents an interface, the array contains objects
1290 * representing all interfaces directly extended by the interface. The
1291 * order of the interface objects in the array corresponds to the order of
1292 * the interface names in the {@code extends} clause of the declaration of
1293 * the interface represented by this {@code Class} object.
1294 *
1295 * <p>If this {@code Class} object represents a class or interface that implements no
1296 * interfaces, the method returns an array of length 0.
1297 *
1298 * <p>If this {@code Class} object represents a primitive type or void, the method
1299 * returns an array of length 0.
1300 *
1301 * <p>If this {@code Class} object represents an array type, the
1302 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1303 * returned in that order.
1304 *
1305 * @throws java.lang.reflect.GenericSignatureFormatError
1306 * if the generic class signature does not conform to the
1307 * format specified in section {@jvms 4.7.9} of <cite>The
1308 * Java Virtual Machine Specification</cite>
1309 * @throws TypeNotPresentException if any of the generic
1310 * superinterfaces refers to a non-existent type declaration
1311 * @throws java.lang.reflect.MalformedParameterizedTypeException
1312 * if any of the generic superinterfaces refer to a parameterized
1313 * type that cannot be instantiated for any reason
1314 * @return an array of interfaces directly implemented by this class
1315 * @since 1.5
1316 */
1317 public Type[] getGenericInterfaces() {
1318 ClassRepository info = getGenericInfo();
1319 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1320 }
1321
1322
1323 /**
1324 * Returns the {@code Class} representing the component type of an
1325 * array. If this class does not represent an array class this method
1326 * returns null.
1327 *
1328 * @return the {@code Class} representing the component type of this
1329 * class if this class is an array
1330 * @see java.lang.reflect.Array
1331 * @since 1.1
1332 */
1333 public Class<?> getComponentType() {
1334 return componentType;
1335 }
1336
1337 // The componentType field's null value is the sole indication that the class
1338 // is an array - see isArray().
1339 private transient final Class<?> componentType;
1340
1341 /*
1342 * Returns the {@code Class} representing the element type of an array class.
1343 * If this class does not represent an array class, then this method returns
1344 * {@code null}.
1345 */
1346 private Class<?> elementType() {
1347 if (!isArray()) return null;
1348
1349 Class<?> c = this;
1350 while (c.isArray()) {
1351 c = c.getComponentType();
1352 }
1353 return c;
1354 }
1355
1356 /**
1357 * Returns the Java language modifiers for this class or interface, encoded
1358 * in an integer. The modifiers consist of the Java Virtual Machine's
1359 * constants for {@code public}, {@code protected},
1360 * {@code private}, {@code final}, {@code static},
1361 * {@code abstract} and {@code interface}; they should be decoded
1362 * using the methods of class {@code Modifier}.
1363 *
1364 * <p> If the underlying class is an array class:
1365 * <ul>
1366 * <li> its {@code public}, {@code private} and {@code protected}
1367 * modifiers are the same as those of its component type
1368 * <li> its {@code abstract} and {@code final} modifiers are always
1369 * {@code true}
1370 * <li> its interface modifier is always {@code false}, even when
1371 * the component type is an interface
1372 * </ul>
1373 * If this {@code Class} object represents a primitive type or
1374 * void, its {@code public}, {@code abstract}, and {@code final}
1375 * modifiers are always {@code true}.
1376 * For {@code Class} objects representing void, primitive types, and
1377 * arrays, the values of other modifiers are {@code false} other
1378 * than as specified above.
1379 *
1380 * <p> The modifier encodings are defined in section {@jvms 4.1}
1381 * of <cite>The Java Virtual Machine Specification</cite>.
1382 *
1383 * @return the {@code int} representing the modifiers for this class
1384 * @see java.lang.reflect.Modifier
1385 * @see #accessFlags()
1386 * @see <a
1387 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
1388 * programming language and JVM modeling in core reflection</a>
1389 * @since 1.1
1390 * @jls 8.1.1 Class Modifiers
1391 * @jls 9.1.1 Interface Modifiers
1392 * @jvms 4.1 The {@code ClassFile} Structure
1393 */
1394 public int getModifiers() { return modifiers; }
1395
1396 /**
1397 * {@return an unmodifiable set of the {@linkplain AccessFlag access
1398 * flags} for this class, possibly empty}
1399 *
1400 * <p> If the underlying class is an array class:
1401 * <ul>
1402 * <li> its {@code PUBLIC}, {@code PRIVATE} and {@code PROTECTED}
1403 * access flags are the same as those of its component type
1404 * <li> its {@code ABSTRACT} and {@code FINAL} flags are present
1405 * <li> its {@code INTERFACE} flag is absent, even when the
1406 * component type is an interface
1407 * </ul>
1408 * If this {@code Class} object represents a primitive type or
1409 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
1410 * {@code FINAL}.
1411 * For {@code Class} objects representing void, primitive types, and
1412 * arrays, access flags are absent other than as specified above.
1413 *
1414 * @see #getModifiers()
1415 * @jvms 4.1 The ClassFile Structure
1416 * @jvms 4.7.6 The InnerClasses Attribute
1417 * @since 20
1418 */
1419 public Set<AccessFlag> accessFlags() {
1420 // Location.CLASS allows SUPER and AccessFlag.MODULE which
1421 // INNER_CLASS forbids. INNER_CLASS allows PRIVATE, PROTECTED,
1422 // and STATIC, which are not allowed on Location.CLASS.
1423 // Use getClassFileAccessFlags to expose SUPER status.
1424 var location = (isMemberClass() || isLocalClass() ||
1425 isAnonymousClass() || isArray()) ?
1426 AccessFlag.Location.INNER_CLASS :
1427 AccessFlag.Location.CLASS;
1428 return getReflectionFactory().parseAccessFlags((location == AccessFlag.Location.CLASS) ?
1429 getClassFileAccessFlags() : getModifiers(), location, this);
1430 }
1431
1432 /**
1433 * Gets the signers of this class.
1434 *
1435 * @return the signers of this class, or null if there are no signers. In
1436 * particular, this method returns null if this {@code Class} object represents
1437 * a primitive type or void.
1438 * @since 1.1
1439 */
1440 public Object[] getSigners() {
1441 var signers = this.signers;
1442 return signers == null ? null : signers.clone();
1443 }
1444
1445 /**
1446 * Set the signers of this class.
1447 */
1448 void setSigners(Object[] signers) {
1449 if (!isPrimitive() && !isArray()) {
1450 this.signers = signers;
1451 }
1452 }
1453
1454 /**
1455 * If this {@code Class} object represents a local or anonymous
1456 * class within a method, returns a {@link
1457 * java.lang.reflect.Method Method} object representing the
1458 * immediately enclosing method of the underlying class. Returns
1459 * {@code null} otherwise.
1460 *
1461 * In particular, this method returns {@code null} if the underlying
1462 * class is a local or anonymous class immediately enclosed by a class or
1463 * interface declaration, instance initializer or static initializer.
1464 *
1465 * @return the immediately enclosing method of the underlying class, if
1466 * that class is a local or anonymous class; otherwise {@code null}.
1467 *
1468 * @since 1.5
1469 */
1470 public Method getEnclosingMethod() {
1471 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1472
1473 if (enclosingInfo == null)
1474 return null;
1475 else {
1476 if (!enclosingInfo.isMethod())
1477 return null;
1478
1479 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1480 getFactory());
1481 Class<?> returnType = toClass(typeInfo.getReturnType());
1482 Type [] parameterTypes = typeInfo.getParameterTypes();
1483 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1484
1485 // Convert Types to Classes; returned types *should*
1486 // be class objects since the methodDescriptor's used
1487 // don't have generics information
1488 for(int i = 0; i < parameterClasses.length; i++)
1489 parameterClasses[i] = toClass(parameterTypes[i]);
1490
1491 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1492 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1493
1494 /*
1495 * Loop over all declared methods; match method name,
1496 * number of and type of parameters, *and* return
1497 * type. Matching return type is also necessary
1498 * because of covariant returns, etc.
1499 */
1500 ReflectionFactory fact = getReflectionFactory();
1501 for (Method m : candidates) {
1502 if (m.getName().equals(enclosingInfo.getName()) &&
1503 arrayContentsEq(parameterClasses,
1504 fact.getExecutableSharedParameterTypes(m))) {
1505 // finally, check return type
1506 if (m.getReturnType().equals(returnType)) {
1507 return fact.copyMethod(m);
1508 }
1509 }
1510 }
1511
1512 throw new InternalError("Enclosing method not found");
1513 }
1514 }
1515
1516 private native Object[] getEnclosingMethod0();
1517
1518 private EnclosingMethodInfo getEnclosingMethodInfo() {
1519 Object[] enclosingInfo = getEnclosingMethod0();
1520 if (enclosingInfo == null)
1521 return null;
1522 else {
1523 return new EnclosingMethodInfo(enclosingInfo);
1524 }
1525 }
1526
1527 private static final class EnclosingMethodInfo {
1528 private final Class<?> enclosingClass;
1529 private final String name;
1530 private final String descriptor;
1531
1532 static void validate(Object[] enclosingInfo) {
1533 if (enclosingInfo.length != 3)
1534 throw new InternalError("Malformed enclosing method information");
1535 try {
1536 // The array is expected to have three elements:
1537
1538 // the immediately enclosing class
1539 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1540 assert(enclosingClass != null);
1541
1542 // the immediately enclosing method or constructor's
1543 // name (can be null).
1544 String name = (String)enclosingInfo[1];
1545
1546 // the immediately enclosing method or constructor's
1547 // descriptor (null iff name is).
1548 String descriptor = (String)enclosingInfo[2];
1549 assert((name != null && descriptor != null) || name == descriptor);
1550 } catch (ClassCastException cce) {
1551 throw new InternalError("Invalid type in enclosing method information", cce);
1552 }
1553 }
1554
1555 EnclosingMethodInfo(Object[] enclosingInfo) {
1556 validate(enclosingInfo);
1557 this.enclosingClass = (Class<?>)enclosingInfo[0];
1558 this.name = (String)enclosingInfo[1];
1559 this.descriptor = (String)enclosingInfo[2];
1560 }
1561
1562 boolean isPartial() {
1563 return enclosingClass == null || name == null || descriptor == null;
1564 }
1565
1566 boolean isConstructor() { return !isPartial() && ConstantDescs.INIT_NAME.equals(name); }
1567
1568 boolean isMethod() { return !isPartial() && !isConstructor() && !ConstantDescs.CLASS_INIT_NAME.equals(name); }
1569
1570 Class<?> getEnclosingClass() { return enclosingClass; }
1571
1572 String getName() { return name; }
1573
1574 String getDescriptor() { return descriptor; }
1575
1576 }
1577
1578 private static Class<?> toClass(Type o) {
1579 if (o instanceof GenericArrayType gat)
1580 return toClass(gat.getGenericComponentType()).arrayType();
1581 return (Class<?>)o;
1582 }
1583
1584 /**
1585 * If this {@code Class} object represents a local or anonymous
1586 * class within a constructor, returns a {@link
1587 * java.lang.reflect.Constructor Constructor} object representing
1588 * the immediately enclosing constructor of the underlying
1589 * class. Returns {@code null} otherwise. In particular, this
1590 * method returns {@code null} if the underlying class is a local
1591 * or anonymous class immediately enclosed by a class or
1592 * interface declaration, instance initializer or static initializer.
1593 *
1594 * @return the immediately enclosing constructor of the underlying class, if
1595 * that class is a local or anonymous class; otherwise {@code null}.
1596 *
1597 * @since 1.5
1598 */
1599 public Constructor<?> getEnclosingConstructor() {
1600 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1601
1602 if (enclosingInfo == null)
1603 return null;
1604 else {
1605 if (!enclosingInfo.isConstructor())
1606 return null;
1607
1608 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1609 getFactory());
1610 Type [] parameterTypes = typeInfo.getParameterTypes();
1611 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1612
1613 // Convert Types to Classes; returned types *should*
1614 // be class objects since the methodDescriptor's used
1615 // don't have generics information
1616 for (int i = 0; i < parameterClasses.length; i++)
1617 parameterClasses[i] = toClass(parameterTypes[i]);
1618
1619
1620 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1621 Constructor<?>[] candidates = enclosingCandidate
1622 .privateGetDeclaredConstructors(false);
1623 /*
1624 * Loop over all declared constructors; match number
1625 * of and type of parameters.
1626 */
1627 ReflectionFactory fact = getReflectionFactory();
1628 for (Constructor<?> c : candidates) {
1629 if (arrayContentsEq(parameterClasses,
1630 fact.getExecutableSharedParameterTypes(c))) {
1631 return fact.copyConstructor(c);
1632 }
1633 }
1634
1635 throw new InternalError("Enclosing constructor not found");
1636 }
1637 }
1638
1639
1640 /**
1641 * If the class or interface represented by this {@code Class} object
1642 * is a member of another class, returns the {@code Class} object
1643 * representing the class in which it was declared. This method returns
1644 * null if this class or interface is not a member of any other class. If
1645 * this {@code Class} object represents an array class, a primitive
1646 * type, or void, then this method returns null.
1647 *
1648 * @return the declaring class for this class
1649 * @since 1.1
1650 */
1651 public Class<?> getDeclaringClass() {
1652 return getDeclaringClass0();
1653 }
1654
1655 private native Class<?> getDeclaringClass0();
1656
1657
1658 /**
1659 * Returns the immediately enclosing class of the underlying
1660 * class. If the underlying class is a top level class this
1661 * method returns {@code null}.
1662 * @return the immediately enclosing class of the underlying class
1663 * @since 1.5
1664 */
1665 public Class<?> getEnclosingClass() {
1666 // There are five kinds of classes (or interfaces):
1667 // a) Top level classes
1668 // b) Nested classes (static member classes)
1669 // c) Inner classes (non-static member classes)
1670 // d) Local classes (named classes declared within a method)
1671 // e) Anonymous classes
1672
1673
1674 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1675 // attribute if and only if it is a local class or an
1676 // anonymous class.
1677 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1678 Class<?> enclosingCandidate;
1679
1680 if (enclosingInfo == null) {
1681 // This is a top level or a nested class or an inner class (a, b, or c)
1682 enclosingCandidate = getDeclaringClass0();
1683 } else {
1684 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1685 // This is a local class or an anonymous class (d or e)
1686 if (enclosingClass == this || enclosingClass == null)
1687 throw new InternalError("Malformed enclosing method information");
1688 else
1689 enclosingCandidate = enclosingClass;
1690 }
1691 return enclosingCandidate;
1692 }
1693
1694 /**
1695 * Returns the simple name of the underlying class as given in the
1696 * source code. An empty string is returned if the underlying class is
1697 * {@linkplain #isAnonymousClass() anonymous}.
1698 * A {@linkplain #isSynthetic() synthetic class}, one not present
1699 * in source code, can have a non-empty name including special
1700 * characters, such as "{@code $}".
1701 *
1702 * <p>The simple name of an {@linkplain #isArray() array class} is the simple name of the
1703 * component type with "[]" appended. In particular the simple
1704 * name of an array class whose component type is anonymous is "[]".
1705 *
1706 * @return the simple name of the underlying class
1707 * @since 1.5
1708 */
1709 public String getSimpleName() {
1710 ReflectionData<T> rd = reflectionData();
1711 String simpleName = rd.simpleName;
1712 if (simpleName == null) {
1713 rd.simpleName = simpleName = getSimpleName0();
1714 }
1715 return simpleName;
1716 }
1717
1718 private String getSimpleName0() {
1719 if (isArray()) {
1720 return getComponentType().getSimpleName().concat("[]");
1721 }
1722 String simpleName = getSimpleBinaryName();
1723 if (simpleName == null) { // top level class
1724 simpleName = getName();
1725 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1726 }
1727 return simpleName;
1728 }
1729
1730 /**
1731 * Return an informative string for the name of this class or interface.
1732 *
1733 * @return an informative string for the name of this class or interface
1734 * @since 1.8
1735 */
1736 public String getTypeName() {
1737 if (isArray()) {
1738 try {
1739 Class<?> cl = this;
1740 int dimensions = 0;
1741 do {
1742 dimensions++;
1743 cl = cl.getComponentType();
1744 } while (cl.isArray());
1745 return cl.getName().concat("[]".repeat(dimensions));
1746 } catch (Throwable e) { /*FALLTHRU*/ }
1747 }
1748 return getName();
1749 }
1750
1751 /**
1752 * Returns the canonical name of the underlying class as
1753 * defined by <cite>The Java Language Specification</cite>.
1754 * Returns {@code null} if the underlying class does not have a canonical
1755 * name. Classes without canonical names include:
1756 * <ul>
1757 * <li>a {@linkplain #isLocalClass() local class}
1758 * <li>a {@linkplain #isAnonymousClass() anonymous class}
1759 * <li>a {@linkplain #isHidden() hidden class}
1760 * <li>an array whose component type does not have a canonical name</li>
1761 * </ul>
1762 *
1763 * The canonical name for a primitive class is the keyword for the
1764 * corresponding primitive type ({@code byte}, {@code short},
1765 * {@code char}, {@code int}, and so on).
1766 *
1767 * <p>An array type has a canonical name if and only if its
1768 * component type has a canonical name. When an array type has a
1769 * canonical name, it is equal to the canonical name of the
1770 * component type followed by "{@code []}".
1771 *
1772 * @return the canonical name of the underlying class if it exists, and
1773 * {@code null} otherwise.
1774 * @jls 6.7 Fully Qualified Names and Canonical Names
1775 * @since 1.5
1776 */
1777 public String getCanonicalName() {
1778 ReflectionData<T> rd = reflectionData();
1779 String canonicalName = rd.canonicalName;
1780 if (canonicalName == null) {
1781 rd.canonicalName = canonicalName = getCanonicalName0();
1782 }
1783 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1784 }
1785
1786 private String getCanonicalName0() {
1787 if (isArray()) {
1788 String canonicalName = getComponentType().getCanonicalName();
1789 if (canonicalName != null)
1790 return canonicalName.concat("[]");
1791 else
1792 return ReflectionData.NULL_SENTINEL;
1793 }
1794 if (isHidden() || isLocalOrAnonymousClass())
1795 return ReflectionData.NULL_SENTINEL;
1796 Class<?> enclosingClass = getEnclosingClass();
1797 if (enclosingClass == null) { // top level class
1798 return getName();
1799 } else {
1800 String enclosingName = enclosingClass.getCanonicalName();
1801 if (enclosingName == null)
1802 return ReflectionData.NULL_SENTINEL;
1803 String simpleName = getSimpleName();
1804 return new StringBuilder(enclosingName.length() + simpleName.length() + 1)
1805 .append(enclosingName)
1806 .append('.')
1807 .append(simpleName)
1808 .toString();
1809 }
1810 }
1811
1812 /**
1813 * Returns {@code true} if and only if the underlying class
1814 * is an anonymous class.
1815 *
1816 * @apiNote
1817 * An anonymous class is not a {@linkplain #isHidden() hidden class}.
1818 *
1819 * @return {@code true} if and only if this class is an anonymous class.
1820 * @since 1.5
1821 * @jls 15.9.5 Anonymous Class Declarations
1822 */
1823 public boolean isAnonymousClass() {
1824 return !isArray() && isLocalOrAnonymousClass() &&
1825 getSimpleBinaryName0() == null;
1826 }
1827
1828 /**
1829 * Returns {@code true} if and only if the underlying class
1830 * is a local class.
1831 *
1832 * @return {@code true} if and only if this class is a local class.
1833 * @since 1.5
1834 * @jls 14.3 Local Class and Interface Declarations
1835 */
1836 public boolean isLocalClass() {
1837 return isLocalOrAnonymousClass() &&
1838 (isArray() || getSimpleBinaryName0() != null);
1839 }
1840
1841 /**
1842 * Returns {@code true} if and only if the underlying class
1843 * is a member class.
1844 *
1845 * @return {@code true} if and only if this class is a member class.
1846 * @since 1.5
1847 * @jls 8.5 Member Class and Interface Declarations
1848 */
1849 public boolean isMemberClass() {
1850 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1851 }
1852
1853 /**
1854 * Returns the "simple binary name" of the underlying class, i.e.,
1855 * the binary name without the leading enclosing class name.
1856 * Returns {@code null} if the underlying class is a top level
1857 * class.
1858 */
1859 private String getSimpleBinaryName() {
1860 if (isTopLevelClass())
1861 return null;
1862 String name = getSimpleBinaryName0();
1863 if (name == null) // anonymous class
1864 return "";
1865 return name;
1866 }
1867
1868 private native String getSimpleBinaryName0();
1869
1870 /**
1871 * Returns {@code true} if this is a top level class. Returns {@code false}
1872 * otherwise.
1873 */
1874 private boolean isTopLevelClass() {
1875 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1876 }
1877
1878 /**
1879 * Returns {@code true} if this is a local class or an anonymous
1880 * class. Returns {@code false} otherwise.
1881 */
1882 private boolean isLocalOrAnonymousClass() {
1883 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1884 // attribute if and only if it is a local class or an
1885 // anonymous class.
1886 return hasEnclosingMethodInfo();
1887 }
1888
1889 private boolean hasEnclosingMethodInfo() {
1890 Object[] enclosingInfo = getEnclosingMethod0();
1891 if (enclosingInfo != null) {
1892 EnclosingMethodInfo.validate(enclosingInfo);
1893 return true;
1894 }
1895 return false;
1896 }
1897
1898 /**
1899 * Returns an array containing {@code Class} objects representing all
1900 * the public classes and interfaces that are members of the class
1901 * represented by this {@code Class} object. This includes public
1902 * class and interface members inherited from superclasses and public class
1903 * and interface members declared by the class. This method returns an
1904 * array of length 0 if this {@code Class} object has no public member
1905 * classes or interfaces. This method also returns an array of length 0 if
1906 * this {@code Class} object represents a primitive type, an array
1907 * class, or void.
1908 *
1909 * @return the array of {@code Class} objects representing the public
1910 * members of this class
1911 * @since 1.1
1912 */
1913 public Class<?>[] getClasses() {
1914 List<Class<?>> list = new ArrayList<>();
1915 Class<?> currentClass = Class.this;
1916 while (currentClass != null) {
1917 for (Class<?> m : currentClass.getDeclaredClasses()) {
1918 if (Modifier.isPublic(m.getModifiers())) {
1919 list.add(m);
1920 }
1921 }
1922 currentClass = currentClass.getSuperclass();
1923 }
1924 return list.toArray(new Class<?>[0]);
1925 }
1926
1927
1928 /**
1929 * Returns an array containing {@code Field} objects reflecting all
1930 * the accessible public fields of the class or interface represented by
1931 * this {@code Class} object.
1932 *
1933 * <p> If this {@code Class} object represents a class or interface with
1934 * no accessible public fields, then this method returns an array of length
1935 * 0.
1936 *
1937 * <p> If this {@code Class} object represents a class, then this method
1938 * returns the public fields of the class and of all its superclasses and
1939 * superinterfaces.
1940 *
1941 * <p> If this {@code Class} object represents an interface, then this
1942 * method returns the fields of the interface and of all its
1943 * superinterfaces.
1944 *
1945 * <p> If this {@code Class} object represents an array type, a primitive
1946 * type, or void, then this method returns an array of length 0.
1947 *
1948 * <p> The elements in the returned array are not sorted and are not in any
1949 * particular order.
1950 *
1951 * @return the array of {@code Field} objects representing the
1952 * public fields
1953 *
1954 * @since 1.1
1955 * @jls 8.2 Class Members
1956 * @jls 8.3 Field Declarations
1957 */
1958 public Field[] getFields() {
1959 return copyFields(privateGetPublicFields());
1960 }
1961
1962
1963 /**
1964 * Returns an array containing {@code Method} objects reflecting all the
1965 * public methods of the class or interface represented by this {@code
1966 * Class} object, including those declared by the class or interface and
1967 * those inherited from superclasses and superinterfaces.
1968 *
1969 * <p> If this {@code Class} object represents an array type, then the
1970 * returned array has a {@code Method} object for each of the public
1971 * methods inherited by the array type from {@code Object}. It does not
1972 * contain a {@code Method} object for {@code clone()}.
1973 *
1974 * <p> If this {@code Class} object represents an interface then the
1975 * returned array does not contain any implicitly declared methods from
1976 * {@code Object}. Therefore, if no methods are explicitly declared in
1977 * this interface or any of its superinterfaces then the returned array
1978 * has length 0. (Note that a {@code Class} object which represents a class
1979 * always has public methods, inherited from {@code Object}.)
1980 *
1981 * <p> The returned array never contains methods with names {@value
1982 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
1983 *
1984 * <p> The elements in the returned array are not sorted and are not in any
1985 * particular order.
1986 *
1987 * <p> Generally, the result is computed as with the following 4 step algorithm.
1988 * Let C be the class or interface represented by this {@code Class} object:
1989 * <ol>
1990 * <li> A union of methods is composed of:
1991 * <ol type="a">
1992 * <li> C's declared public instance and static methods as returned by
1993 * {@link #getDeclaredMethods()} and filtered to include only public
1994 * methods.</li>
1995 * <li> If C is a class other than {@code Object}, then include the result
1996 * of invoking this algorithm recursively on the superclass of C.</li>
1997 * <li> Include the results of invoking this algorithm recursively on all
1998 * direct superinterfaces of C, but include only instance methods.</li>
1999 * </ol></li>
2000 * <li> Union from step 1 is partitioned into subsets of methods with same
2001 * signature (name, parameter types) and return type.</li>
2002 * <li> Within each such subset only the most specific methods are selected.
2003 * Let method M be a method from a set of methods with same signature
2004 * and return type. M is most specific if there is no such method
2005 * N != M from the same set, such that N is more specific than M.
2006 * N is more specific than M if:
2007 * <ol type="a">
2008 * <li> N is declared by a class and M is declared by an interface; or</li>
2009 * <li> N and M are both declared by classes or both by interfaces and
2010 * N's declaring type is the same as or a subtype of M's declaring type
2011 * (clearly, if M's and N's declaring types are the same type, then
2012 * M and N are the same method).</li>
2013 * </ol></li>
2014 * <li> The result of this algorithm is the union of all selected methods from
2015 * step 3.</li>
2016 * </ol>
2017 *
2018 * @apiNote There may be more than one method with a particular name
2019 * and parameter types in a class because while the Java language forbids a
2020 * class to declare multiple methods with the same signature but different
2021 * return types, the Java virtual machine does not. This
2022 * increased flexibility in the virtual machine can be used to
2023 * implement various language features. For example, covariant
2024 * returns can be implemented with {@linkplain
2025 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2026 * method and the overriding method would have the same
2027 * signature but different return types.
2028 *
2029 * @return the array of {@code Method} objects representing the
2030 * public methods of this class
2031 *
2032 * @jls 8.2 Class Members
2033 * @jls 8.4 Method Declarations
2034 * @since 1.1
2035 */
2036 public Method[] getMethods() {
2037 return copyMethods(privateGetPublicMethods());
2038 }
2039
2040
2041 /**
2042 * Returns an array containing {@code Constructor} objects reflecting
2043 * all the public constructors of the class represented by this
2044 * {@code Class} object. An array of length 0 is returned if the
2045 * class has no public constructors, or if the class is an array class, or
2046 * if the class reflects a primitive type or void.
2047 *
2048 * @apiNote
2049 * While this method returns an array of {@code
2050 * Constructor<T>} objects (that is an array of constructors from
2051 * this class), the return type of this method is {@code
2052 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
2053 * might be expected. This less informative return type is
2054 * necessary since after being returned from this method, the
2055 * array could be modified to hold {@code Constructor} objects for
2056 * different classes, which would violate the type guarantees of
2057 * {@code Constructor<T>[]}.
2058 *
2059 * @return the array of {@code Constructor} objects representing the
2060 * public constructors of this class
2061 *
2062 * @see #getDeclaredConstructors()
2063 * @since 1.1
2064 */
2065 public Constructor<?>[] getConstructors() {
2066 return copyConstructors(privateGetDeclaredConstructors(true));
2067 }
2068
2069
2070 /**
2071 * Returns a {@code Field} object that reflects the specified public member
2072 * field of the class or interface represented by this {@code Class}
2073 * object. The {@code name} parameter is a {@code String} specifying the
2074 * simple name of the desired field.
2075 *
2076 * <p> The field to be reflected is determined by the algorithm that
2077 * follows. Let C be the class or interface represented by this {@code Class} object:
2078 *
2079 * <OL>
2080 * <LI> If C declares a public field with the name specified, that is the
2081 * field to be reflected.</LI>
2082 * <LI> If no field was found in step 1 above, this algorithm is applied
2083 * recursively to each direct superinterface of C. The direct
2084 * superinterfaces are searched in the order they were declared.</LI>
2085 * <LI> If no field was found in steps 1 and 2 above, and C has a
2086 * superclass S, then this algorithm is invoked recursively upon S.
2087 * If C has no superclass, then a {@code NoSuchFieldException}
2088 * is thrown.</LI>
2089 * </OL>
2090 *
2091 * <p> If this {@code Class} object represents an array type, then this
2092 * method does not find the {@code length} field of the array type.
2093 *
2094 * @param name the field name
2095 * @return the {@code Field} object of this class specified by
2096 * {@code name}
2097 * @throws NoSuchFieldException if a field with the specified name is
2098 * not found.
2099 * @throws NullPointerException if {@code name} is {@code null}
2100 *
2101 * @since 1.1
2102 * @jls 8.2 Class Members
2103 * @jls 8.3 Field Declarations
2104 */
2105 public Field getField(String name) throws NoSuchFieldException {
2106 Objects.requireNonNull(name);
2107 Field field = getField0(name);
2108 if (field == null) {
2109 throw new NoSuchFieldException(name);
2110 }
2111 return getReflectionFactory().copyField(field);
2112 }
2113
2114
2115 /**
2116 * Returns a {@code Method} object that reflects the specified public
2117 * member method of the class or interface represented by this
2118 * {@code Class} object. The {@code name} parameter is a
2119 * {@code String} specifying the simple name of the desired method. The
2120 * {@code parameterTypes} parameter is an array of {@code Class}
2121 * objects that identify the method's formal parameter types, in declared
2122 * order. If {@code parameterTypes} is {@code null}, it is
2123 * treated as if it were an empty array.
2124 *
2125 * <p> If this {@code Class} object represents an array type, then this
2126 * method finds any public method inherited by the array type from
2127 * {@code Object} except method {@code clone()}.
2128 *
2129 * <p> If this {@code Class} object represents an interface then this
2130 * method does not find any implicitly declared method from
2131 * {@code Object}. Therefore, if no methods are explicitly declared in
2132 * this interface or any of its superinterfaces, then this method does not
2133 * find any method.
2134 *
2135 * <p> This method does not find any method with name {@value
2136 * ConstantDescs#INIT_NAME} or {@value ConstantDescs#CLASS_INIT_NAME}.
2137 *
2138 * <p> Generally, the method to be reflected is determined by the 4 step
2139 * algorithm that follows.
2140 * Let C be the class or interface represented by this {@code Class} object:
2141 * <ol>
2142 * <li> A union of methods is composed of:
2143 * <ol type="a">
2144 * <li> C's declared public instance and static methods as returned by
2145 * {@link #getDeclaredMethods()} and filtered to include only public
2146 * methods that match given {@code name} and {@code parameterTypes}</li>
2147 * <li> If C is a class other than {@code Object}, then include the result
2148 * of invoking this algorithm recursively on the superclass of C.</li>
2149 * <li> Include the results of invoking this algorithm recursively on all
2150 * direct superinterfaces of C, but include only instance methods.</li>
2151 * </ol></li>
2152 * <li> This union is partitioned into subsets of methods with same
2153 * return type (the selection of methods from step 1 also guarantees that
2154 * they have the same method name and parameter types).</li>
2155 * <li> Within each such subset only the most specific methods are selected.
2156 * Let method M be a method from a set of methods with same VM
2157 * signature (return type, name, parameter types).
2158 * M is most specific if there is no such method N != M from the same
2159 * set, such that N is more specific than M. N is more specific than M
2160 * if:
2161 * <ol type="a">
2162 * <li> N is declared by a class and M is declared by an interface; or</li>
2163 * <li> N and M are both declared by classes or both by interfaces and
2164 * N's declaring type is the same as or a subtype of M's declaring type
2165 * (clearly, if M's and N's declaring types are the same type, then
2166 * M and N are the same method).</li>
2167 * </ol></li>
2168 * <li> The result of this algorithm is chosen arbitrarily from the methods
2169 * with most specific return type among all selected methods from step 3.
2170 * Let R be a return type of a method M from the set of all selected methods
2171 * from step 3. M is a method with most specific return type if there is
2172 * no such method N != M from the same set, having return type S != R,
2173 * such that S is a subtype of R as determined by
2174 * R.class.{@link #isAssignableFrom}(S.class).
2175 * </ol>
2176 *
2177 * @apiNote There may be more than one method with matching name and
2178 * parameter types in a class because while the Java language forbids a
2179 * class to declare multiple methods with the same signature but different
2180 * return types, the Java virtual machine does not. This
2181 * increased flexibility in the virtual machine can be used to
2182 * implement various language features. For example, covariant
2183 * returns can be implemented with {@linkplain
2184 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2185 * method and the overriding method would have the same
2186 * signature but different return types. This method would return the
2187 * overriding method as it would have a more specific return type.
2188 *
2189 * @param name the name of the method
2190 * @param parameterTypes the list of parameters
2191 * @return the {@code Method} object that matches the specified
2192 * {@code name} and {@code parameterTypes}
2193 * @throws NoSuchMethodException if a matching method is not found
2194 * or if the name is {@value ConstantDescs#INIT_NAME} or
2195 * {@value ConstantDescs#CLASS_INIT_NAME}.
2196 * @throws NullPointerException if {@code name} is {@code null}
2197 *
2198 * @jls 8.2 Class Members
2199 * @jls 8.4 Method Declarations
2200 * @since 1.1
2201 */
2202 public Method getMethod(String name, Class<?>... parameterTypes)
2203 throws NoSuchMethodException {
2204 Objects.requireNonNull(name);
2205 Method method = getMethod0(name, parameterTypes);
2206 if (method == null) {
2207 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2208 }
2209 return getReflectionFactory().copyMethod(method);
2210 }
2211
2212 /**
2213 * Returns a {@code Constructor} object that reflects the specified
2214 * public constructor of the class represented by this {@code Class}
2215 * object. The {@code parameterTypes} parameter is an array of
2216 * {@code Class} objects that identify the constructor's formal
2217 * parameter types, in declared order.
2218 *
2219 * If this {@code Class} object represents an inner class
2220 * declared in a non-static context, the formal parameter types
2221 * include the explicit enclosing instance as the first parameter.
2222 *
2223 * <p> The constructor to reflect is the public constructor of the class
2224 * represented by this {@code Class} object whose formal parameter
2225 * types match those specified by {@code parameterTypes}.
2226 *
2227 * @param parameterTypes the parameter array
2228 * @return the {@code Constructor} object of the public constructor that
2229 * matches the specified {@code parameterTypes}
2230 * @throws NoSuchMethodException if a matching constructor is not found,
2231 * including when this {@code Class} object represents
2232 * an interface, a primitive type, an array class, or void.
2233 *
2234 * @see #getDeclaredConstructor(Class[])
2235 * @since 1.1
2236 */
2237 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2238 throws NoSuchMethodException {
2239 return getReflectionFactory().copyConstructor(
2240 getConstructor0(parameterTypes, Member.PUBLIC));
2241 }
2242
2243
2244 /**
2245 * Returns an array of {@code Class} objects reflecting all the
2246 * classes and interfaces declared as members of the class represented by
2247 * this {@code Class} object. This includes public, protected, default
2248 * (package) access, and private classes and interfaces declared by the
2249 * class, but excludes inherited classes and interfaces. This method
2250 * returns an array of length 0 if the class declares no classes or
2251 * interfaces as members, or if this {@code Class} object represents a
2252 * primitive type, an array class, or void.
2253 *
2254 * @return the array of {@code Class} objects representing all the
2255 * declared members of this class
2256 *
2257 * @since 1.1
2258 * @jls 8.5 Member Class and Interface Declarations
2259 */
2260 public Class<?>[] getDeclaredClasses() {
2261 return getDeclaredClasses0();
2262 }
2263
2264
2265 /**
2266 * Returns an array of {@code Field} objects reflecting all the fields
2267 * declared by the class or interface represented by this
2268 * {@code Class} object. This includes public, protected, default
2269 * (package) access, and private fields, but excludes inherited fields.
2270 *
2271 * <p> If this {@code Class} object represents a class or interface with no
2272 * declared fields, then this method returns an array of length 0.
2273 *
2274 * <p> If this {@code Class} object represents an array type, a primitive
2275 * type, or void, then this method returns an array of length 0.
2276 *
2277 * <p> The elements in the returned array are not sorted and are not in any
2278 * particular order.
2279 *
2280 * @return the array of {@code Field} objects representing all the
2281 * declared fields of this class
2282 *
2283 * @since 1.1
2284 * @jls 8.2 Class Members
2285 * @jls 8.3 Field Declarations
2286 */
2287 public Field[] getDeclaredFields() {
2288 return copyFields(privateGetDeclaredFields(false));
2289 }
2290
2291 /**
2292 * Returns an array of {@code RecordComponent} objects representing all the
2293 * record components of this record class, or {@code null} if this class is
2294 * not a record class.
2295 *
2296 * <p> The components are returned in the same order that they are declared
2297 * in the record header. The array is empty if this record class has no
2298 * components. If the class is not a record class, that is {@link
2299 * #isRecord()} returns {@code false}, then this method returns {@code null}.
2300 * Conversely, if {@link #isRecord()} returns {@code true}, then this method
2301 * returns a non-null value.
2302 *
2303 * @apiNote
2304 * <p> The following method can be used to find the record canonical constructor:
2305 *
2306 * {@snippet lang="java" :
2307 * static <T extends Record> Constructor<T> getCanonicalConstructor(Class<T> cls)
2308 * throws NoSuchMethodException {
2309 * Class<?>[] paramTypes =
2310 * Arrays.stream(cls.getRecordComponents())
2311 * .map(RecordComponent::getType)
2312 * .toArray(Class<?>[]::new);
2313 * return cls.getDeclaredConstructor(paramTypes);
2314 * }}
2315 *
2316 * @return An array of {@code RecordComponent} objects representing all the
2317 * record components of this record class, or {@code null} if this
2318 * class is not a record class
2319 *
2320 * @jls 8.10 Record Classes
2321 * @since 16
2322 */
2323 public RecordComponent[] getRecordComponents() {
2324 if (!isRecord()) {
2325 return null;
2326 }
2327 return getRecordComponents0();
2328 }
2329
2330 /**
2331 * Returns an array containing {@code Method} objects reflecting all the
2332 * declared methods of the class or interface represented by this {@code
2333 * Class} object, including public, protected, default (package)
2334 * access, and private methods, but excluding inherited methods.
2335 * The declared methods may include methods <em>not</em> in the
2336 * source of the class or interface, including {@linkplain
2337 * Method#isBridge bridge methods} and other {@linkplain
2338 * Executable#isSynthetic synthetic} methods added by compilers.
2339 *
2340 * <p> If this {@code Class} object represents a class or interface that
2341 * has multiple declared methods with the same name and parameter types,
2342 * but different return types, then the returned array has a {@code Method}
2343 * object for each such method.
2344 *
2345 * <p> If this {@code Class} object represents a class or interface that
2346 * has a class initialization method {@value ConstantDescs#CLASS_INIT_NAME},
2347 * then the returned array does <em>not</em> have a corresponding {@code
2348 * Method} object.
2349 *
2350 * <p> If this {@code Class} object represents a class or interface with no
2351 * declared methods, then the returned array has length 0.
2352 *
2353 * <p> If this {@code Class} object represents an array type, a primitive
2354 * type, or void, then the returned array has length 0.
2355 *
2356 * <p> The elements in the returned array are not sorted and are not in any
2357 * particular order.
2358 *
2359 * @return the array of {@code Method} objects representing all the
2360 * declared methods of this class
2361 *
2362 * @jls 8.2 Class Members
2363 * @jls 8.4 Method Declarations
2364 * @see <a
2365 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
2366 * programming language and JVM modeling in core reflection</a>
2367 * @since 1.1
2368 */
2369 public Method[] getDeclaredMethods() {
2370 return copyMethods(privateGetDeclaredMethods(false));
2371 }
2372
2373 /**
2374 * Returns an array of {@code Constructor} objects reflecting all the
2375 * constructors implicitly or explicitly declared by the class represented by this
2376 * {@code Class} object. These are public, protected, default
2377 * (package) access, and private constructors. The elements in the array
2378 * returned are not sorted and are not in any particular order. If the
2379 * class has a default constructor (JLS {@jls 8.8.9}), it is included in the returned array.
2380 * If a record class has a canonical constructor (JLS {@jls
2381 * 8.10.4.1}, {@jls 8.10.4.2}), it is included in the returned array.
2382 *
2383 * This method returns an array of length 0 if this {@code Class}
2384 * object represents an interface, a primitive type, an array class, or
2385 * void.
2386 *
2387 * @return the array of {@code Constructor} objects representing all the
2388 * declared constructors of this class
2389 *
2390 * @since 1.1
2391 * @see #getConstructors()
2392 * @jls 8.8 Constructor Declarations
2393 */
2394 public Constructor<?>[] getDeclaredConstructors() {
2395 return copyConstructors(privateGetDeclaredConstructors(false));
2396 }
2397
2398
2399 /**
2400 * Returns a {@code Field} object that reflects the specified declared
2401 * field of the class or interface represented by this {@code Class}
2402 * object. The {@code name} parameter is a {@code String} that specifies
2403 * the simple name of the desired field.
2404 *
2405 * <p> If this {@code Class} object represents an array type, then this
2406 * method does not find the {@code length} field of the array type.
2407 *
2408 * @param name the name of the field
2409 * @return the {@code Field} object for the specified field in this
2410 * class
2411 * @throws NoSuchFieldException if a field with the specified name is
2412 * not found.
2413 * @throws NullPointerException if {@code name} is {@code null}
2414 *
2415 * @since 1.1
2416 * @jls 8.2 Class Members
2417 * @jls 8.3 Field Declarations
2418 */
2419 public Field getDeclaredField(String name) throws NoSuchFieldException {
2420 Objects.requireNonNull(name);
2421 Field field = searchFields(privateGetDeclaredFields(false), name);
2422 if (field == null) {
2423 throw new NoSuchFieldException(name);
2424 }
2425 return getReflectionFactory().copyField(field);
2426 }
2427
2428
2429 /**
2430 * Returns a {@code Method} object that reflects the specified
2431 * declared method of the class or interface represented by this
2432 * {@code Class} object. The {@code name} parameter is a
2433 * {@code String} that specifies the simple name of the desired
2434 * method, and the {@code parameterTypes} parameter is an array of
2435 * {@code Class} objects that identify the method's formal parameter
2436 * types, in declared order. If more than one method with the same
2437 * parameter types is declared in a class, and one of these methods has a
2438 * return type that is more specific than any of the others, that method is
2439 * returned; otherwise one of the methods is chosen arbitrarily. If the
2440 * name is {@value ConstantDescs#INIT_NAME} or {@value
2441 * ConstantDescs#CLASS_INIT_NAME} a {@code NoSuchMethodException}
2442 * is raised.
2443 *
2444 * <p> If this {@code Class} object represents an array type, then this
2445 * method does not find the {@code clone()} method.
2446 *
2447 * @param name the name of the method
2448 * @param parameterTypes the parameter array
2449 * @return the {@code Method} object for the method of this class
2450 * matching the specified name and parameters
2451 * @throws NoSuchMethodException if a matching method is not found.
2452 * @throws NullPointerException if {@code name} is {@code null}
2453 *
2454 * @jls 8.2 Class Members
2455 * @jls 8.4 Method Declarations
2456 * @since 1.1
2457 */
2458 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2459 throws NoSuchMethodException {
2460 Objects.requireNonNull(name);
2461 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2462 if (method == null) {
2463 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2464 }
2465 return getReflectionFactory().copyMethod(method);
2466 }
2467
2468 /**
2469 * Returns the list of {@code Method} objects for the declared public
2470 * methods of this class or interface that have the specified method name
2471 * and parameter types.
2472 *
2473 * @param name the name of the method
2474 * @param parameterTypes the parameter array
2475 * @return the list of {@code Method} objects for the public methods of
2476 * this class matching the specified name and parameters
2477 */
2478 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2479 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2480 ReflectionFactory factory = getReflectionFactory();
2481 List<Method> result = new ArrayList<>();
2482 for (Method method : methods) {
2483 if (method.getName().equals(name)
2484 && Arrays.equals(
2485 factory.getExecutableSharedParameterTypes(method),
2486 parameterTypes)) {
2487 result.add(factory.copyMethod(method));
2488 }
2489 }
2490 return result;
2491 }
2492
2493 /**
2494 * Returns the most specific {@code Method} object of this class, super class or
2495 * interface that have the specified method name and parameter types.
2496 *
2497 * @param publicOnly true if only public methods are examined, otherwise all methods
2498 * @param name the name of the method
2499 * @param parameterTypes the parameter array
2500 * @return the {@code Method} object for the method found from this class matching
2501 * the specified name and parameters, or null if not found
2502 */
2503 Method findMethod(boolean publicOnly, String name, Class<?>... parameterTypes) {
2504 PublicMethods.MethodList res = getMethodsRecursive(name, parameterTypes, true, publicOnly);
2505 return res == null ? null : getReflectionFactory().copyMethod(res.getMostSpecific());
2506 }
2507
2508 /**
2509 * Returns a {@code Constructor} object that reflects the specified
2510 * constructor of the class represented by this
2511 * {@code Class} object. The {@code parameterTypes} parameter is
2512 * an array of {@code Class} objects that identify the constructor's
2513 * formal parameter types, in declared order.
2514 *
2515 * If this {@code Class} object represents an inner class
2516 * declared in a non-static context, the formal parameter types
2517 * include the explicit enclosing instance as the first parameter.
2518 *
2519 * @param parameterTypes the parameter array
2520 * @return The {@code Constructor} object for the constructor with the
2521 * specified parameter list
2522 * @throws NoSuchMethodException if a matching constructor is not found,
2523 * including when this {@code Class} object represents
2524 * an interface, a primitive type, an array class, or void.
2525 *
2526 * @see #getConstructor(Class[])
2527 * @since 1.1
2528 */
2529 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2530 throws NoSuchMethodException {
2531 return getReflectionFactory().copyConstructor(
2532 getConstructor0(parameterTypes, Member.DECLARED));
2533 }
2534
2535 /**
2536 * Finds a resource with a given name.
2537 *
2538 * <p> If this class is in a named {@link Module Module} then this method
2539 * will attempt to find the resource in the module. This is done by
2540 * delegating to the module's class loader {@link
2541 * ClassLoader#findResource(String,String) findResource(String,String)}
2542 * method, invoking it with the module name and the absolute name of the
2543 * resource. Resources in named modules are subject to the rules for
2544 * encapsulation specified in the {@code Module} {@link
2545 * Module#getResourceAsStream getResourceAsStream} method and so this
2546 * method returns {@code null} when the resource is a
2547 * non-"{@code .class}" resource in a package that is not open to the
2548 * caller's module.
2549 *
2550 * <p> Otherwise, if this class is not in a named module then the rules for
2551 * searching resources associated with a given class are implemented by the
2552 * defining {@linkplain ClassLoader class loader} of the class. This method
2553 * delegates to this {@code Class} object's class loader.
2554 * If this {@code Class} object was loaded by the bootstrap class loader,
2555 * the method delegates to {@link ClassLoader#getSystemResourceAsStream}.
2556 *
2557 * <p> Before delegation, an absolute resource name is constructed from the
2558 * given resource name using this algorithm:
2559 *
2560 * <ul>
2561 *
2562 * <li> If the {@code name} begins with a {@code '/'}
2563 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2564 * portion of the {@code name} following the {@code '/'}.
2565 *
2566 * <li> Otherwise, the absolute name is of the following form:
2567 *
2568 * <blockquote>
2569 * {@code modified_package_name/name}
2570 * </blockquote>
2571 *
2572 * <p> Where the {@code modified_package_name} is the package name of this
2573 * object with {@code '/'} substituted for {@code '.'}
2574 * (<code>'\u002e'</code>).
2575 *
2576 * </ul>
2577 *
2578 * @param name name of the desired resource
2579 * @return A {@link java.io.InputStream} object; {@code null} if no
2580 * resource with this name is found, or the resource is in a package
2581 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2582 * least the caller module.
2583 * @throws NullPointerException If {@code name} is {@code null}
2584 *
2585 * @see Module#getResourceAsStream(String)
2586 * @since 1.1
2587 */
2588 @CallerSensitive
2589 public InputStream getResourceAsStream(String name) {
2590 name = resolveName(name);
2591
2592 Module thisModule = getModule();
2593 if (thisModule.isNamed()) {
2594 // check if resource can be located by caller
2595 if (Resources.canEncapsulate(name)
2596 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2597 return null;
2598 }
2599
2600 // resource not encapsulated or in package open to caller
2601 String mn = thisModule.getName();
2602 ClassLoader cl = classLoader;
2603 try {
2604
2605 // special-case built-in class loaders to avoid the
2606 // need for a URL connection
2607 if (cl == null) {
2608 return BootLoader.findResourceAsStream(mn, name);
2609 } else if (cl instanceof BuiltinClassLoader bcl) {
2610 return bcl.findResourceAsStream(mn, name);
2611 } else {
2612 URL url = cl.findResource(mn, name);
2613 return (url != null) ? url.openStream() : null;
2614 }
2615
2616 } catch (IOException | SecurityException e) {
2617 return null;
2618 }
2619 }
2620
2621 // unnamed module
2622 ClassLoader cl = classLoader;
2623 if (cl == null) {
2624 return ClassLoader.getSystemResourceAsStream(name);
2625 } else {
2626 return cl.getResourceAsStream(name);
2627 }
2628 }
2629
2630 /**
2631 * Finds a resource with a given name.
2632 *
2633 * <p> If this class is in a named {@link Module Module} then this method
2634 * will attempt to find the resource in the module. This is done by
2635 * delegating to the module's class loader {@link
2636 * ClassLoader#findResource(String,String) findResource(String,String)}
2637 * method, invoking it with the module name and the absolute name of the
2638 * resource. Resources in named modules are subject to the rules for
2639 * encapsulation specified in the {@code Module} {@link
2640 * Module#getResourceAsStream getResourceAsStream} method and so this
2641 * method returns {@code null} when the resource is a
2642 * non-"{@code .class}" resource in a package that is not open to the
2643 * caller's module.
2644 *
2645 * <p> Otherwise, if this class is not in a named module then the rules for
2646 * searching resources associated with a given class are implemented by the
2647 * defining {@linkplain ClassLoader class loader} of the class. This method
2648 * delegates to this {@code Class} object's class loader.
2649 * If this {@code Class} object was loaded by the bootstrap class loader,
2650 * the method delegates to {@link ClassLoader#getSystemResource}.
2651 *
2652 * <p> Before delegation, an absolute resource name is constructed from the
2653 * given resource name using this algorithm:
2654 *
2655 * <ul>
2656 *
2657 * <li> If the {@code name} begins with a {@code '/'}
2658 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2659 * portion of the {@code name} following the {@code '/'}.
2660 *
2661 * <li> Otherwise, the absolute name is of the following form:
2662 *
2663 * <blockquote>
2664 * {@code modified_package_name/name}
2665 * </blockquote>
2666 *
2667 * <p> Where the {@code modified_package_name} is the package name of this
2668 * object with {@code '/'} substituted for {@code '.'}
2669 * (<code>'\u002e'</code>).
2670 *
2671 * </ul>
2672 *
2673 * @param name name of the desired resource
2674 * @return A {@link java.net.URL} object; {@code null} if no resource with
2675 * this name is found, the resource cannot be located by a URL, or the
2676 * resource is in a package that is not
2677 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2678 * module.
2679 * @throws NullPointerException If {@code name} is {@code null}
2680 * @since 1.1
2681 */
2682 @CallerSensitive
2683 public URL getResource(String name) {
2684 name = resolveName(name);
2685
2686 Module thisModule = getModule();
2687 if (thisModule.isNamed()) {
2688 // check if resource can be located by caller
2689 if (Resources.canEncapsulate(name)
2690 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2691 return null;
2692 }
2693
2694 // resource not encapsulated or in package open to caller
2695 String mn = thisModule.getName();
2696 ClassLoader cl = classLoader;
2697 try {
2698 if (cl == null) {
2699 return BootLoader.findResource(mn, name);
2700 } else {
2701 return cl.findResource(mn, name);
2702 }
2703 } catch (IOException ioe) {
2704 return null;
2705 }
2706 }
2707
2708 // unnamed module
2709 ClassLoader cl = classLoader;
2710 if (cl == null) {
2711 return ClassLoader.getSystemResource(name);
2712 } else {
2713 return cl.getResource(name);
2714 }
2715 }
2716
2717 /**
2718 * Returns true if a resource with the given name can be located by the
2719 * given caller. All resources in a module can be located by code in
2720 * the module. For other callers, then the package needs to be open to
2721 * the caller.
2722 */
2723 private boolean isOpenToCaller(String name, Class<?> caller) {
2724 // assert getModule().isNamed();
2725 Module thisModule = getModule();
2726 Module callerModule = (caller != null) ? caller.getModule() : null;
2727 if (callerModule != thisModule) {
2728 String pn = Resources.toPackageName(name);
2729 if (thisModule.getDescriptor().packages().contains(pn)) {
2730 if (callerModule == null) {
2731 // no caller, return true if the package is open to all modules
2732 return thisModule.isOpen(pn);
2733 }
2734 if (!thisModule.isOpen(pn, callerModule)) {
2735 // package not open to caller
2736 return false;
2737 }
2738 }
2739 }
2740 return true;
2741 }
2742
2743 private transient final ProtectionDomain protectionDomain;
2744
2745 /** Holder for the protection domain returned when the internal domain is null */
2746 private static class Holder {
2747 private static final ProtectionDomain allPermDomain;
2748 static {
2749 Permissions perms = new Permissions();
2750 perms.add(new AllPermission());
2751 allPermDomain = new ProtectionDomain(null, perms);
2752 }
2753 }
2754
2755 /**
2756 * Returns the {@code ProtectionDomain} of this class.
2757 *
2758 * @return the ProtectionDomain of this class
2759 *
2760 * @see java.security.ProtectionDomain
2761 * @since 1.2
2762 */
2763 public ProtectionDomain getProtectionDomain() {
2764 if (protectionDomain == null) {
2765 return Holder.allPermDomain;
2766 } else {
2767 return protectionDomain;
2768 }
2769 }
2770
2771 /*
2772 * Returns the Class object for the named primitive type. Type parameter T
2773 * avoids redundant casts for trusted code.
2774 */
2775 static native <T> Class<T> getPrimitiveClass(String name);
2776
2777 /**
2778 * Add a package name prefix if the name is not absolute. Remove leading "/"
2779 * if name is absolute
2780 */
2781 private String resolveName(String name) {
2782 if (!name.startsWith("/")) {
2783 String baseName = getPackageName();
2784 if (!baseName.isEmpty()) {
2785 int len = baseName.length() + 1 + name.length();
2786 StringBuilder sb = new StringBuilder(len);
2787 name = sb.append(baseName.replace('.', '/'))
2788 .append('/')
2789 .append(name)
2790 .toString();
2791 }
2792 } else {
2793 name = name.substring(1);
2794 }
2795 return name;
2796 }
2797
2798 /**
2799 * Atomic operations support.
2800 */
2801 private static class Atomic {
2802 // initialize Unsafe machinery here, since we need to call Class.class instance method
2803 // and have to avoid calling it in the static initializer of the Class class...
2804 private static final Unsafe unsafe = Unsafe.getUnsafe();
2805 // offset of Class.reflectionData instance field
2806 private static final long reflectionDataOffset
2807 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2808 // offset of Class.annotationType instance field
2809 private static final long annotationTypeOffset
2810 = unsafe.objectFieldOffset(Class.class, "annotationType");
2811 // offset of Class.annotationData instance field
2812 private static final long annotationDataOffset
2813 = unsafe.objectFieldOffset(Class.class, "annotationData");
2814
2815 static <T> boolean casReflectionData(Class<?> clazz,
2816 ReflectionData<T> oldData,
2817 ReflectionData<T> newData) {
2818 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2819 }
2820
2821 static boolean casAnnotationType(Class<?> clazz,
2822 AnnotationType oldType,
2823 AnnotationType newType) {
2824 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2825 }
2826
2827 static boolean casAnnotationData(Class<?> clazz,
2828 AnnotationData oldData,
2829 AnnotationData newData) {
2830 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2831 }
2832 }
2833
2834 /**
2835 * Reflection support.
2836 */
2837
2838 // Reflection data caches various derived names and reflective members. Cached
2839 // values may be invalidated when JVM TI RedefineClasses() is called
2840 private static class ReflectionData<T> {
2841 volatile Field[] declaredFields;
2842 volatile Field[] publicFields;
2843 volatile Method[] declaredMethods;
2844 volatile Method[] publicMethods;
2845 volatile Constructor<T>[] declaredConstructors;
2846 volatile Constructor<T>[] publicConstructors;
2847 // Intermediate results for getFields and getMethods
2848 volatile Field[] declaredPublicFields;
2849 volatile Method[] declaredPublicMethods;
2850 volatile Class<?>[] interfaces;
2851
2852 // Cached names
2853 String simpleName;
2854 String canonicalName;
2855 static final String NULL_SENTINEL = new String();
2856
2857 // Value of classRedefinedCount when we created this ReflectionData instance
2858 final int redefinedCount;
2859
2860 ReflectionData(int redefinedCount) {
2861 this.redefinedCount = redefinedCount;
2862 }
2863 }
2864
2865 private transient volatile ReflectionData<T> reflectionData;
2866
2867 // Incremented by the VM on each call to JVM TI RedefineClasses()
2868 // that redefines this class or a superclass.
2869 private transient volatile int classRedefinedCount;
2870
2871 // Lazily create and cache ReflectionData
2872 private ReflectionData<T> reflectionData() {
2873 ReflectionData<T> reflectionData = this.reflectionData;
2874 int classRedefinedCount = this.classRedefinedCount;
2875 if (reflectionData != null &&
2876 reflectionData.redefinedCount == classRedefinedCount) {
2877 return reflectionData;
2878 }
2879 // else no SoftReference or cleared SoftReference or stale ReflectionData
2880 // -> create and replace new instance
2881 return newReflectionData(reflectionData, classRedefinedCount);
2882 }
2883
2884 private ReflectionData<T> newReflectionData(ReflectionData<T> oldReflectionData,
2885 int classRedefinedCount) {
2886 while (true) {
2887 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
2888 // try to CAS it...
2889 if (Atomic.casReflectionData(this, oldReflectionData, rd)) {
2890 return rd;
2891 }
2892 // else retry
2893 oldReflectionData = this.reflectionData;
2894 classRedefinedCount = this.classRedefinedCount;
2895 if (oldReflectionData != null && oldReflectionData.redefinedCount == classRedefinedCount) {
2896 return rd;
2897 }
2898 }
2899 }
2900
2901 // Generic signature handling
2902 private native String getGenericSignature0();
2903
2904 // Generic info repository; lazily initialized
2905 private transient volatile ClassRepository genericInfo;
2906
2907 // accessor for factory
2908 private GenericsFactory getFactory() {
2909 // create scope and factory
2910 return CoreReflectionFactory.make(this, ClassScope.make(this));
2911 }
2912
2913 // accessor for generic info repository;
2914 // generic info is lazily initialized
2915 private ClassRepository getGenericInfo() {
2916 ClassRepository genericInfo = this.genericInfo;
2917 if (genericInfo == null) {
2918 String signature = getGenericSignature0();
2919 if (signature == null) {
2920 genericInfo = ClassRepository.NONE;
2921 } else {
2922 genericInfo = ClassRepository.make(signature, getFactory());
2923 }
2924 this.genericInfo = genericInfo;
2925 }
2926 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
2927 }
2928
2929 // Annotations handling
2930 native byte[] getRawAnnotations();
2931 // Since 1.8
2932 native byte[] getRawTypeAnnotations();
2933 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
2934 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
2935 }
2936
2937 native ConstantPool getConstantPool();
2938
2939 //
2940 //
2941 // java.lang.reflect.Field handling
2942 //
2943 //
2944
2945 // Returns an array of "root" fields. These Field objects must NOT
2946 // be propagated to the outside world, but must instead be copied
2947 // via ReflectionFactory.copyField.
2948 private Field[] privateGetDeclaredFields(boolean publicOnly) {
2949 Field[] res;
2950 ReflectionData<T> rd = reflectionData();
2951 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
2952 if (res != null) return res;
2953 // No cached value available; request value from VM
2954 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
2955 if (publicOnly) {
2956 rd.declaredPublicFields = res;
2957 } else {
2958 rd.declaredFields = res;
2959 }
2960 return res;
2961 }
2962
2963 // Returns an array of "root" fields. These Field objects must NOT
2964 // be propagated to the outside world, but must instead be copied
2965 // via ReflectionFactory.copyField.
2966 private Field[] privateGetPublicFields() {
2967 Field[] res;
2968 ReflectionData<T> rd = reflectionData();
2969 res = rd.publicFields;
2970 if (res != null) return res;
2971
2972 // Use a linked hash set to ensure order is preserved and
2973 // fields from common super interfaces are not duplicated
2974 LinkedHashSet<Field> fields = new LinkedHashSet<>();
2975
2976 // Local fields
2977 addAll(fields, privateGetDeclaredFields(true));
2978
2979 // Direct superinterfaces, recursively
2980 for (Class<?> si : getInterfaces(/* cloneArray */ false)) {
2981 addAll(fields, si.privateGetPublicFields());
2982 }
2983
2984 // Direct superclass, recursively
2985 Class<?> sc = getSuperclass();
2986 if (sc != null) {
2987 addAll(fields, sc.privateGetPublicFields());
2988 }
2989
2990 res = fields.toArray(new Field[0]);
2991 rd.publicFields = res;
2992 return res;
2993 }
2994
2995 private static void addAll(Collection<Field> c, Field[] o) {
2996 for (Field f : o) {
2997 c.add(f);
2998 }
2999 }
3000
3001
3002 //
3003 //
3004 // java.lang.reflect.Constructor handling
3005 //
3006 //
3007
3008 // Returns an array of "root" constructors. These Constructor
3009 // objects must NOT be propagated to the outside world, but must
3010 // instead be copied via ReflectionFactory.copyConstructor.
3011 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3012 Constructor<T>[] res;
3013 ReflectionData<T> rd = reflectionData();
3014 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3015 if (res != null) return res;
3016 // No cached value available; request value from VM
3017 if (isInterface()) {
3018 @SuppressWarnings("unchecked")
3019 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3020 res = temporaryRes;
3021 } else {
3022 res = getDeclaredConstructors0(publicOnly);
3023 }
3024 if (publicOnly) {
3025 rd.publicConstructors = res;
3026 } else {
3027 rd.declaredConstructors = res;
3028 }
3029 return res;
3030 }
3031
3032 //
3033 //
3034 // java.lang.reflect.Method handling
3035 //
3036 //
3037
3038 // Returns an array of "root" methods. These Method objects must NOT
3039 // be propagated to the outside world, but must instead be copied
3040 // via ReflectionFactory.copyMethod.
3041 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3042 Method[] res;
3043 ReflectionData<T> rd = reflectionData();
3044 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3045 if (res != null) return res;
3046 // No cached value available; request value from VM
3047 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3048 if (publicOnly) {
3049 rd.declaredPublicMethods = res;
3050 } else {
3051 rd.declaredMethods = res;
3052 }
3053 return res;
3054 }
3055
3056 // Returns an array of "root" methods. These Method objects must NOT
3057 // be propagated to the outside world, but must instead be copied
3058 // via ReflectionFactory.copyMethod.
3059 private Method[] privateGetPublicMethods() {
3060 Method[] res;
3061 ReflectionData<T> rd = reflectionData();
3062 res = rd.publicMethods;
3063 if (res != null) return res;
3064
3065 // No cached value available; compute value recursively.
3066 // Start by fetching public declared methods...
3067 PublicMethods pms = new PublicMethods();
3068 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3069 pms.merge(m);
3070 }
3071 // ...then recur over superclass methods...
3072 Class<?> sc = getSuperclass();
3073 if (sc != null) {
3074 for (Method m : sc.privateGetPublicMethods()) {
3075 pms.merge(m);
3076 }
3077 }
3078 // ...and finally over direct superinterfaces.
3079 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3080 for (Method m : intf.privateGetPublicMethods()) {
3081 // static interface methods are not inherited
3082 if (!Modifier.isStatic(m.getModifiers())) {
3083 pms.merge(m);
3084 }
3085 }
3086 }
3087
3088 res = pms.toArray();
3089 rd.publicMethods = res;
3090 return res;
3091 }
3092
3093
3094 //
3095 // Helpers for fetchers of one field, method, or constructor
3096 //
3097
3098 // This method does not copy the returned Field object!
3099 private static Field searchFields(Field[] fields, String name) {
3100 for (Field field : fields) {
3101 if (field.getName().equals(name)) {
3102 return field;
3103 }
3104 }
3105 return null;
3106 }
3107
3108 // Returns a "root" Field object. This Field object must NOT
3109 // be propagated to the outside world, but must instead be copied
3110 // via ReflectionFactory.copyField.
3111 private Field getField0(String name) {
3112 // Note: the intent is that the search algorithm this routine
3113 // uses be equivalent to the ordering imposed by
3114 // privateGetPublicFields(). It fetches only the declared
3115 // public fields for each class, however, to reduce the number
3116 // of Field objects which have to be created for the common
3117 // case where the field being requested is declared in the
3118 // class which is being queried.
3119 Field res;
3120 // Search declared public fields
3121 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3122 return res;
3123 }
3124 // Direct superinterfaces, recursively
3125 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3126 for (Class<?> c : interfaces) {
3127 if ((res = c.getField0(name)) != null) {
3128 return res;
3129 }
3130 }
3131 // Direct superclass, recursively
3132 if (!isInterface()) {
3133 Class<?> c = getSuperclass();
3134 if (c != null) {
3135 if ((res = c.getField0(name)) != null) {
3136 return res;
3137 }
3138 }
3139 }
3140 return null;
3141 }
3142
3143 // This method does not copy the returned Method object!
3144 private static Method searchMethods(Method[] methods,
3145 String name,
3146 Class<?>[] parameterTypes)
3147 {
3148 ReflectionFactory fact = getReflectionFactory();
3149 Method res = null;
3150 for (Method m : methods) {
3151 if (m.getName().equals(name)
3152 && arrayContentsEq(parameterTypes,
3153 fact.getExecutableSharedParameterTypes(m))
3154 && (res == null
3155 || (res.getReturnType() != m.getReturnType()
3156 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3157 res = m;
3158 }
3159 return res;
3160 }
3161
3162 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3163
3164 // Returns a "root" Method object. This Method object must NOT
3165 // be propagated to the outside world, but must instead be copied
3166 // via ReflectionFactory.copyMethod.
3167 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3168 PublicMethods.MethodList res = getMethodsRecursive(
3169 name,
3170 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3171 /* includeStatic */ true, /* publicOnly */ true);
3172 return res == null ? null : res.getMostSpecific();
3173 }
3174
3175 // Returns a list of "root" Method objects. These Method objects must NOT
3176 // be propagated to the outside world, but must instead be copied
3177 // via ReflectionFactory.copyMethod.
3178 private PublicMethods.MethodList getMethodsRecursive(String name,
3179 Class<?>[] parameterTypes,
3180 boolean includeStatic,
3181 boolean publicOnly) {
3182 // 1st check declared methods
3183 Method[] methods = privateGetDeclaredMethods(publicOnly);
3184 PublicMethods.MethodList res = PublicMethods.MethodList
3185 .filter(methods, name, parameterTypes, includeStatic);
3186 // if there is at least one match among declared methods, we need not
3187 // search any further as such match surely overrides matching methods
3188 // declared in superclass(es) or interface(s).
3189 if (res != null) {
3190 return res;
3191 }
3192
3193 // if there was no match among declared methods,
3194 // we must consult the superclass (if any) recursively...
3195 Class<?> sc = getSuperclass();
3196 if (sc != null) {
3197 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic, publicOnly);
3198 }
3199
3200 // ...and coalesce the superclass methods with methods obtained
3201 // from directly implemented interfaces excluding static methods...
3202 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3203 res = PublicMethods.MethodList.merge(
3204 res, intf.getMethodsRecursive(name, parameterTypes, /* includeStatic */ false, publicOnly));
3205 }
3206
3207 return res;
3208 }
3209
3210 // Returns a "root" Constructor object. This Constructor object must NOT
3211 // be propagated to the outside world, but must instead be copied
3212 // via ReflectionFactory.copyConstructor.
3213 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3214 int which) throws NoSuchMethodException
3215 {
3216 ReflectionFactory fact = getReflectionFactory();
3217 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3218 for (Constructor<T> constructor : constructors) {
3219 if (arrayContentsEq(parameterTypes,
3220 fact.getExecutableSharedParameterTypes(constructor))) {
3221 return constructor;
3222 }
3223 }
3224 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3225 }
3226
3227 //
3228 // Other helpers and base implementation
3229 //
3230
3231 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3232 if (a1 == null) {
3233 return a2 == null || a2.length == 0;
3234 }
3235
3236 if (a2 == null) {
3237 return a1.length == 0;
3238 }
3239
3240 if (a1.length != a2.length) {
3241 return false;
3242 }
3243
3244 for (int i = 0; i < a1.length; i++) {
3245 if (a1[i] != a2[i]) {
3246 return false;
3247 }
3248 }
3249
3250 return true;
3251 }
3252
3253 private static Field[] copyFields(Field[] arg) {
3254 Field[] out = new Field[arg.length];
3255 ReflectionFactory fact = getReflectionFactory();
3256 for (int i = 0; i < arg.length; i++) {
3257 out[i] = fact.copyField(arg[i]);
3258 }
3259 return out;
3260 }
3261
3262 private static Method[] copyMethods(Method[] arg) {
3263 Method[] out = new Method[arg.length];
3264 ReflectionFactory fact = getReflectionFactory();
3265 for (int i = 0; i < arg.length; i++) {
3266 out[i] = fact.copyMethod(arg[i]);
3267 }
3268 return out;
3269 }
3270
3271 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3272 Constructor<U>[] out = arg.clone();
3273 ReflectionFactory fact = getReflectionFactory();
3274 for (int i = 0; i < out.length; i++) {
3275 out[i] = fact.copyConstructor(out[i]);
3276 }
3277 return out;
3278 }
3279
3280 private native Field[] getDeclaredFields0(boolean publicOnly);
3281 private native Method[] getDeclaredMethods0(boolean publicOnly);
3282 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3283 private native Class<?>[] getDeclaredClasses0();
3284
3285 /*
3286 * Returns an array containing the components of the Record attribute,
3287 * or null if the attribute is not present.
3288 *
3289 * Note that this method returns non-null array on a class with
3290 * the Record attribute even if this class is not a record.
3291 */
3292 private native RecordComponent[] getRecordComponents0();
3293 private native boolean isRecord0();
3294
3295 /**
3296 * Helper method to get the method name from arguments.
3297 */
3298 private String methodToString(String name, Class<?>[] argTypes) {
3299 return getName() + '.' + name +
3300 ((argTypes == null || argTypes.length == 0) ?
3301 "()" :
3302 Arrays.stream(argTypes)
3303 .map(c -> c == null ? "null" : c.getName())
3304 .collect(Collectors.joining(",", "(", ")")));
3305 }
3306
3307 /** use serialVersionUID from JDK 1.1 for interoperability */
3308 @java.io.Serial
3309 private static final long serialVersionUID = 3206093459760846163L;
3310
3311
3312 /**
3313 * Class Class is special cased within the Serialization Stream Protocol.
3314 *
3315 * A Class instance is written initially into an ObjectOutputStream in the
3316 * following format:
3317 * <pre>
3318 * {@code TC_CLASS} ClassDescriptor
3319 * A ClassDescriptor is a special cased serialization of
3320 * a {@code java.io.ObjectStreamClass} instance.
3321 * </pre>
3322 * A new handle is generated for the initial time the class descriptor
3323 * is written into the stream. Future references to the class descriptor
3324 * are written as references to the initial class descriptor instance.
3325 *
3326 * @see java.io.ObjectStreamClass
3327 */
3328 @java.io.Serial
3329 private static final ObjectStreamField[] serialPersistentFields =
3330 new ObjectStreamField[0];
3331
3332
3333 /**
3334 * Returns the assertion status that would be assigned to this
3335 * class if it were to be initialized at the time this method is invoked.
3336 * If this class has had its assertion status set, the most recent
3337 * setting will be returned; otherwise, if any package default assertion
3338 * status pertains to this class, the most recent setting for the most
3339 * specific pertinent package default assertion status is returned;
3340 * otherwise, if this class is not a system class (i.e., it has a
3341 * class loader) its class loader's default assertion status is returned;
3342 * otherwise, the system class default assertion status is returned.
3343 *
3344 * @apiNote
3345 * Few programmers will have any need for this method; it is provided
3346 * for the benefit of the JDK itself. (It allows a class to determine at
3347 * the time that it is initialized whether assertions should be enabled.)
3348 * Note that this method is not guaranteed to return the actual
3349 * assertion status that was (or will be) associated with the specified
3350 * class when it was (or will be) initialized.
3351 *
3352 * @return the desired assertion status of the specified class.
3353 * @see java.lang.ClassLoader#setClassAssertionStatus
3354 * @see java.lang.ClassLoader#setPackageAssertionStatus
3355 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3356 * @since 1.4
3357 */
3358 public boolean desiredAssertionStatus() {
3359 ClassLoader loader = classLoader;
3360 // If the loader is null this is a system class, so ask the VM
3361 if (loader == null)
3362 return desiredAssertionStatus0(this);
3363
3364 // If the classloader has been initialized with the assertion
3365 // directives, ask it. Otherwise, ask the VM.
3366 synchronized(loader.assertionLock) {
3367 if (loader.classAssertionStatus != null) {
3368 return loader.desiredAssertionStatus(getName());
3369 }
3370 }
3371 return desiredAssertionStatus0(this);
3372 }
3373
3374 // Retrieves the desired assertion status of this class from the VM
3375 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3376
3377 /**
3378 * Returns true if and only if this class was declared as an enum in the
3379 * source code.
3380 *
3381 * Note that {@link java.lang.Enum} is not itself an enum class.
3382 *
3383 * Also note that if an enum constant is declared with a class body,
3384 * the class of that enum constant object is an anonymous class
3385 * and <em>not</em> the class of the declaring enum class. The
3386 * {@link Enum#getDeclaringClass} method of an enum constant can
3387 * be used to get the class of the enum class declaring the
3388 * constant.
3389 *
3390 * @return true if and only if this class was declared as an enum in the
3391 * source code
3392 * @since 1.5
3393 * @jls 8.9.1 Enum Constants
3394 */
3395 public boolean isEnum() {
3396 // An enum must both directly extend java.lang.Enum and have
3397 // the ENUM bit set; classes for specialized enum constants
3398 // don't do the former.
3399 return (this.getModifiers() & ENUM) != 0 &&
3400 this.getSuperclass() == java.lang.Enum.class;
3401 }
3402
3403 /**
3404 * Returns {@code true} if and only if this class is a record class.
3405 *
3406 * <p> The {@linkplain #getSuperclass() direct superclass} of a record
3407 * class is {@code java.lang.Record}. A record class is {@linkplain
3408 * Modifier#FINAL final}. A record class has (possibly zero) record
3409 * components; {@link #getRecordComponents()} returns a non-null but
3410 * possibly empty value for a record.
3411 *
3412 * <p> Note that class {@link Record} is not a record class and thus
3413 * invoking this method on class {@code Record} returns {@code false}.
3414 *
3415 * @return true if and only if this class is a record class, otherwise false
3416 * @jls 8.10 Record Classes
3417 * @since 16
3418 */
3419 public boolean isRecord() {
3420 // this superclass and final modifier check is not strictly necessary
3421 // they are intrinsified and serve as a fast-path check
3422 return getSuperclass() == java.lang.Record.class &&
3423 (this.getModifiers() & Modifier.FINAL) != 0 &&
3424 isRecord0();
3425 }
3426
3427 // Fetches the factory for reflective objects
3428 private static ReflectionFactory getReflectionFactory() {
3429 var factory = reflectionFactory;
3430 if (factory != null) {
3431 return factory;
3432 }
3433 return reflectionFactory = ReflectionFactory.getReflectionFactory();
3434 }
3435 private static ReflectionFactory reflectionFactory;
3436
3437 /**
3438 * When CDS is enabled, the Class class may be aot-initialized. However,
3439 * we can't archive reflectionFactory, so we reset it to null, so it
3440 * will be allocated again at runtime.
3441 */
3442 private static void resetArchivedStates() {
3443 reflectionFactory = 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 *
3450 * @return an array containing the values comprising the enum class
3451 * represented by this {@code Class} object in the order they're
3452 * declared, or null if this {@code Class} object does not
3453 * represent an enum class
3454 * @since 1.5
3455 * @jls 8.9.1 Enum Constants
3456 */
3457 public T[] getEnumConstants() {
3458 T[] values = getEnumConstantsShared();
3459 return (values != null) ? values.clone() : null;
3460 }
3461
3462 /**
3463 * Returns the elements of this enum class or null if this
3464 * Class object does not represent an enum class;
3465 * identical to getEnumConstants except that the result is
3466 * uncloned, cached, and shared by all callers.
3467 */
3468 T[] getEnumConstantsShared() {
3469 T[] constants = enumConstants;
3470 if (constants == null) {
3471 if (!isEnum()) return null;
3472 try {
3473 final Method values = getMethod("values");
3474 values.setAccessible(true);
3475 @SuppressWarnings("unchecked")
3476 T[] temporaryConstants = (T[])values.invoke(null);
3477 enumConstants = constants = temporaryConstants;
3478 }
3479 // These can happen when users concoct enum-like classes
3480 // that don't comply with the enum spec.
3481 catch (InvocationTargetException | NoSuchMethodException |
3482 IllegalAccessException | NullPointerException |
3483 ClassCastException ex) { return null; }
3484 }
3485 return constants;
3486 }
3487 private transient volatile T[] enumConstants;
3488
3489 /**
3490 * Returns a map from simple name to enum constant. This package-private
3491 * method is used internally by Enum to implement
3492 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3493 * efficiently. Note that the map is returned by this method is
3494 * created lazily on first use. Typically it won't ever get created.
3495 */
3496 Map<String, T> enumConstantDirectory() {
3497 Map<String, T> directory = enumConstantDirectory;
3498 if (directory == null) {
3499 T[] universe = getEnumConstantsShared();
3500 if (universe == null)
3501 throw new IllegalArgumentException(
3502 getName() + " is not an enum class");
3503 directory = HashMap.newHashMap(universe.length);
3504 for (T constant : universe) {
3505 directory.put(((Enum<?>)constant).name(), constant);
3506 }
3507 enumConstantDirectory = directory;
3508 }
3509 return directory;
3510 }
3511 private transient volatile Map<String, T> enumConstantDirectory;
3512
3513 /**
3514 * Casts an object to the class or interface represented
3515 * by this {@code Class} object.
3516 *
3517 * @param obj the object to be cast
3518 * @return the object after casting, or null if obj is null
3519 *
3520 * @throws ClassCastException if the object is not
3521 * null and is not assignable to the type T.
3522 *
3523 * @since 1.5
3524 */
3525 @SuppressWarnings("unchecked")
3526 @IntrinsicCandidate
3527 public T cast(Object obj) {
3528 if (obj != null && !isInstance(obj))
3529 throw new ClassCastException(cannotCastMsg(obj));
3530 return (T) obj;
3531 }
3532
3533 private String cannotCastMsg(Object obj) {
3534 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3535 }
3536
3537 /**
3538 * Casts this {@code Class} object to represent a subclass of the class
3539 * represented by the specified class object. Checks that the cast
3540 * is valid, and throws a {@code ClassCastException} if it is not. If
3541 * this method succeeds, it always returns a reference to this {@code Class} object.
3542 *
3543 * <p>This method is useful when a client needs to "narrow" the type of
3544 * a {@code Class} object to pass it to an API that restricts the
3545 * {@code Class} objects that it is willing to accept. A cast would
3546 * generate a compile-time warning, as the correctness of the cast
3547 * could not be checked at runtime (because generic types are implemented
3548 * by erasure).
3549 *
3550 * @param <U> the type to cast this {@code Class} object to
3551 * @param clazz the class of the type to cast this {@code Class} object to
3552 * @return this {@code Class} object, cast to represent a subclass of
3553 * the specified class object.
3554 * @throws ClassCastException if this {@code Class} object does not
3555 * represent a subclass of the specified class (here "subclass" includes
3556 * the class itself).
3557 * @since 1.5
3558 */
3559 @SuppressWarnings("unchecked")
3560 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3561 if (clazz.isAssignableFrom(this))
3562 return (Class<? extends U>) this;
3563 else
3564 throw new ClassCastException(this.toString());
3565 }
3566
3567 /**
3568 * {@inheritDoc}
3569 * <p>Note that any annotation returned by this method is a
3570 * declaration annotation.
3571 *
3572 * @throws NullPointerException {@inheritDoc}
3573 * @since 1.5
3574 */
3575 @Override
3576 @SuppressWarnings("unchecked")
3577 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3578 Objects.requireNonNull(annotationClass);
3579
3580 return (A) annotationData().annotations.get(annotationClass);
3581 }
3582
3583 /**
3584 * {@inheritDoc}
3585 * @throws NullPointerException {@inheritDoc}
3586 * @since 1.5
3587 */
3588 @Override
3589 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3590 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3591 }
3592
3593 /**
3594 * {@inheritDoc}
3595 * <p>Note that any annotations returned by this method are
3596 * declaration annotations.
3597 *
3598 * @throws NullPointerException {@inheritDoc}
3599 * @since 1.8
3600 */
3601 @Override
3602 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3603 Objects.requireNonNull(annotationClass);
3604
3605 AnnotationData annotationData = annotationData();
3606 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3607 this,
3608 annotationClass);
3609 }
3610
3611 /**
3612 * {@inheritDoc}
3613 * <p>Note that any annotations returned by this method are
3614 * declaration annotations.
3615 *
3616 * @since 1.5
3617 */
3618 @Override
3619 public Annotation[] getAnnotations() {
3620 return AnnotationParser.toArray(annotationData().annotations);
3621 }
3622
3623 /**
3624 * {@inheritDoc}
3625 * <p>Note that any annotation returned by this method is a
3626 * declaration annotation.
3627 *
3628 * @throws NullPointerException {@inheritDoc}
3629 * @since 1.8
3630 */
3631 @Override
3632 @SuppressWarnings("unchecked")
3633 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3634 Objects.requireNonNull(annotationClass);
3635
3636 return (A) annotationData().declaredAnnotations.get(annotationClass);
3637 }
3638
3639 /**
3640 * {@inheritDoc}
3641 * <p>Note that any annotations returned by this method are
3642 * declaration annotations.
3643 *
3644 * @throws NullPointerException {@inheritDoc}
3645 * @since 1.8
3646 */
3647 @Override
3648 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3649 Objects.requireNonNull(annotationClass);
3650
3651 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3652 annotationClass);
3653 }
3654
3655 /**
3656 * {@inheritDoc}
3657 * <p>Note that any annotations returned by this method are
3658 * declaration annotations.
3659 *
3660 * @since 1.5
3661 */
3662 @Override
3663 public Annotation[] getDeclaredAnnotations() {
3664 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3665 }
3666
3667 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3668 private static class AnnotationData {
3669 final Map<Class<? extends Annotation>, Annotation> annotations;
3670 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3671
3672 // Value of classRedefinedCount when we created this AnnotationData instance
3673 final int redefinedCount;
3674
3675 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3676 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3677 int redefinedCount) {
3678 this.annotations = annotations;
3679 this.declaredAnnotations = declaredAnnotations;
3680 this.redefinedCount = redefinedCount;
3681 }
3682 }
3683
3684 // Annotations cache
3685 @SuppressWarnings("UnusedDeclaration")
3686 private transient volatile AnnotationData annotationData;
3687
3688 private AnnotationData annotationData() {
3689 while (true) { // retry loop
3690 AnnotationData annotationData = this.annotationData;
3691 int classRedefinedCount = this.classRedefinedCount;
3692 if (annotationData != null &&
3693 annotationData.redefinedCount == classRedefinedCount) {
3694 return annotationData;
3695 }
3696 // null or stale annotationData -> optimistically create new instance
3697 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3698 // try to install it
3699 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3700 // successfully installed new AnnotationData
3701 return newAnnotationData;
3702 }
3703 }
3704 }
3705
3706 private AnnotationData createAnnotationData(int classRedefinedCount) {
3707 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3708 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3709 Class<?> superClass = getSuperclass();
3710 Map<Class<? extends Annotation>, Annotation> annotations = null;
3711 if (superClass != null) {
3712 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3713 superClass.annotationData().annotations;
3714 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3715 Class<? extends Annotation> annotationClass = e.getKey();
3716 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3717 if (annotations == null) { // lazy construction
3718 annotations = LinkedHashMap.newLinkedHashMap(Math.max(
3719 declaredAnnotations.size(),
3720 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3721 )
3722 );
3723 }
3724 annotations.put(annotationClass, e.getValue());
3725 }
3726 }
3727 }
3728 if (annotations == null) {
3729 // no inherited annotations -> share the Map with declaredAnnotations
3730 annotations = declaredAnnotations;
3731 } else {
3732 // at least one inherited annotation -> declared may override inherited
3733 annotations.putAll(declaredAnnotations);
3734 }
3735 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3736 }
3737
3738 // Annotation interfaces cache their internal (AnnotationType) form
3739
3740 @SuppressWarnings("UnusedDeclaration")
3741 private transient volatile AnnotationType annotationType;
3742
3743 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3744 return Atomic.casAnnotationType(this, oldType, newType);
3745 }
3746
3747 AnnotationType getAnnotationType() {
3748 return annotationType;
3749 }
3750
3751 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3752 return annotationData().declaredAnnotations;
3753 }
3754
3755 /* Backing store of user-defined values pertaining to this class.
3756 * Maintained by the ClassValue class.
3757 */
3758 transient ClassValue.ClassValueMap classValueMap;
3759
3760 /**
3761 * Returns an {@code AnnotatedType} object that represents the use of a
3762 * type to specify the superclass of the entity represented by this {@code
3763 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3764 * in '... extends Foo' is distinct from the <em>declaration</em> of class
3765 * Foo.)
3766 *
3767 * <p> If this {@code Class} object represents a class whose declaration
3768 * does not explicitly indicate an annotated superclass, then the return
3769 * value is an {@code AnnotatedType} object representing an element with no
3770 * annotations.
3771 *
3772 * <p> If this {@code Class} represents either the {@code Object} class, an
3773 * interface type, an array type, a primitive type, or void, the return
3774 * value is {@code null}.
3775 *
3776 * @return an object representing the superclass
3777 * @since 1.8
3778 */
3779 public AnnotatedType getAnnotatedSuperclass() {
3780 if (this == Object.class ||
3781 isInterface() ||
3782 isArray() ||
3783 isPrimitive() ||
3784 this == Void.TYPE) {
3785 return null;
3786 }
3787
3788 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3789 }
3790
3791 /**
3792 * Returns an array of {@code AnnotatedType} objects that represent the use
3793 * of types to specify superinterfaces of the entity represented by this
3794 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3795 * superinterface in '... implements Foo' is distinct from the
3796 * <em>declaration</em> of interface Foo.)
3797 *
3798 * <p> If this {@code Class} object represents a class, the return value is
3799 * an array containing objects representing the uses of interface types to
3800 * specify interfaces implemented by the class. The order of the objects in
3801 * the array corresponds to the order of the interface types used in the
3802 * 'implements' clause of the declaration of this {@code Class} object.
3803 *
3804 * <p> If this {@code Class} object represents an interface, the return
3805 * value is an array containing objects representing the uses of interface
3806 * types to specify interfaces directly extended by the interface. The
3807 * order of the objects in the array corresponds to the order of the
3808 * interface types used in the 'extends' clause of the declaration of this
3809 * {@code Class} object.
3810 *
3811 * <p> If this {@code Class} object represents a class or interface whose
3812 * declaration does not explicitly indicate any annotated superinterfaces,
3813 * the return value is an array of length 0.
3814 *
3815 * <p> If this {@code Class} object represents either the {@code Object}
3816 * class, an array type, a primitive type, or void, the return value is an
3817 * array of length 0.
3818 *
3819 * @return an array representing the superinterfaces
3820 * @since 1.8
3821 */
3822 public AnnotatedType[] getAnnotatedInterfaces() {
3823 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3824 }
3825
3826 private native Class<?> getNestHost0();
3827
3828 /**
3829 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3830 * or interface represented by this {@code Class} object belongs.
3831 * Every class and interface belongs to exactly one nest.
3832 *
3833 * If the nest host of this class or interface has previously
3834 * been determined, then this method returns the nest host.
3835 * If the nest host of this class or interface has
3836 * not previously been determined, then this method determines the nest
3837 * host using the algorithm of JVMS 5.4.4, and returns it.
3838 *
3839 * Often, a class or interface belongs to a nest consisting only of itself,
3840 * in which case this method returns {@code this} to indicate that the class
3841 * or interface is the nest host.
3842 *
3843 * <p>If this {@code Class} object represents a primitive type, an array type,
3844 * or {@code void}, then this method returns {@code this},
3845 * indicating that the represented entity belongs to the nest consisting only of
3846 * itself, and is the nest host.
3847 *
3848 * @return the nest host of this class or interface
3849 *
3850 * @since 11
3851 * @jvms 4.7.28 The {@code NestHost} Attribute
3852 * @jvms 4.7.29 The {@code NestMembers} Attribute
3853 * @jvms 5.4.4 Access Control
3854 */
3855 public Class<?> getNestHost() {
3856 if (isPrimitive() || isArray()) {
3857 return this;
3858 }
3859 return getNestHost0();
3860 }
3861
3862 /**
3863 * Determines if the given {@code Class} is a nestmate of the
3864 * class or interface represented by this {@code Class} object.
3865 * Two classes or interfaces are nestmates
3866 * if they have the same {@linkplain #getNestHost() nest host}.
3867 *
3868 * @param c the class to check
3869 * @return {@code true} if this class and {@code c} are members of
3870 * the same nest; and {@code false} otherwise.
3871 *
3872 * @since 11
3873 */
3874 public boolean isNestmateOf(Class<?> c) {
3875 if (this == c) {
3876 return true;
3877 }
3878 if (isPrimitive() || isArray() ||
3879 c.isPrimitive() || c.isArray()) {
3880 return false;
3881 }
3882
3883 return getNestHost() == c.getNestHost();
3884 }
3885
3886 private native Class<?>[] getNestMembers0();
3887
3888 /**
3889 * Returns an array containing {@code Class} objects representing all the
3890 * classes and interfaces that are members of the nest to which the class
3891 * or interface represented by this {@code Class} object belongs.
3892 *
3893 * First, this method obtains the {@linkplain #getNestHost() nest host},
3894 * {@code H}, of the nest to which the class or interface represented by
3895 * this {@code Class} object belongs. The zeroth element of the returned
3896 * array is {@code H}.
3897 *
3898 * Then, for each class or interface {@code C} which is recorded by {@code H}
3899 * as being a member of its nest, this method attempts to obtain the {@code Class}
3900 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
3901 * loader} of the current {@code Class} object), and then obtains the
3902 * {@linkplain #getNestHost() nest host} of the nest to which {@code C} belongs.
3903 * The classes and interfaces which are recorded by {@code H} as being members
3904 * of its nest, and for which {@code H} can be determined as their nest host,
3905 * are indicated by subsequent elements of the returned array. The order of
3906 * such elements is unspecified. Duplicates are permitted.
3907 *
3908 * <p>If this {@code Class} object represents a primitive type, an array type,
3909 * or {@code void}, then this method returns a single-element array containing
3910 * {@code this}.
3911 *
3912 * @apiNote
3913 * The returned array includes only the nest members recorded in the {@code NestMembers}
3914 * attribute, and not any hidden classes that were added to the nest via
3915 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3916 * Lookup::defineHiddenClass}.
3917 *
3918 * @return an array of all classes and interfaces in the same nest as
3919 * this class or interface
3920 *
3921 * @since 11
3922 * @see #getNestHost()
3923 * @jvms 4.7.28 The {@code NestHost} Attribute
3924 * @jvms 4.7.29 The {@code NestMembers} Attribute
3925 */
3926 public Class<?>[] getNestMembers() {
3927 if (isPrimitive() || isArray()) {
3928 return new Class<?>[] { this };
3929 }
3930 Class<?>[] members = getNestMembers0();
3931 // Can't actually enable this due to bootstrapping issues
3932 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
3933 return members;
3934 }
3935
3936 /**
3937 * Returns the descriptor string of the entity (class, interface, array class,
3938 * primitive type, or {@code void}) represented by this {@code Class} object.
3939 *
3940 * <p> If this {@code Class} object represents a class or interface,
3941 * not an array class, then:
3942 * <ul>
3943 * <li> If the class or interface is not {@linkplain Class#isHidden() hidden},
3944 * then the result is a field descriptor (JVMS {@jvms 4.3.2})
3945 * for the class or interface. Calling
3946 * {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3947 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3948 * describing this class or interface.
3949 * <li> If the class or interface is {@linkplain Class#isHidden() hidden},
3950 * then the result is a string of the form:
3951 * <blockquote>
3952 * {@code "L" +} <em>N</em> {@code + "." + <suffix> + ";"}
3953 * </blockquote>
3954 * where <em>N</em> is the {@linkplain ClassLoader##binary-name binary name}
3955 * encoded in internal form indicated by the {@code class} file passed to
3956 * {@link MethodHandles.Lookup#defineHiddenClass(byte[], boolean, MethodHandles.Lookup.ClassOption...)
3957 * Lookup::defineHiddenClass}, and {@code <suffix>} is an unqualified name.
3958 * A hidden class or interface has no {@linkplain ClassDesc nominal descriptor}.
3959 * The result string is not a type descriptor.
3960 * </ul>
3961 *
3962 * <p> If this {@code Class} object represents an array class, then
3963 * the result is a string consisting of one or more '{@code [}' characters
3964 * representing the depth of the array nesting, followed by the
3965 * descriptor string of the element type.
3966 * <ul>
3967 * <li> If the element type is not a {@linkplain Class#isHidden() hidden} class
3968 * or interface, then this array class can be described nominally.
3969 * Calling {@link ClassDesc#ofDescriptor(String) ClassDesc::ofDescriptor}
3970 * with the result descriptor string produces a {@link ClassDesc ClassDesc}
3971 * describing this array class.
3972 * <li> If the element type is a {@linkplain Class#isHidden() hidden} class or
3973 * interface, then this array class cannot be described nominally.
3974 * The result string is not a type descriptor.
3975 * </ul>
3976 *
3977 * <p> If this {@code Class} object represents a primitive type or
3978 * {@code void}, then the result is a field descriptor string which
3979 * is a one-letter code corresponding to a primitive type or {@code void}
3980 * ({@code "B", "C", "D", "F", "I", "J", "S", "Z", "V"}) (JVMS {@jvms 4.3.2}).
3981 *
3982 * @return the descriptor string for this {@code Class} object
3983 * @jvms 4.3.2 Field Descriptors
3984 * @since 12
3985 */
3986 @Override
3987 public String descriptorString() {
3988 if (isPrimitive())
3989 return Wrapper.forPrimitiveType(this).basicTypeString();
3990
3991 if (isArray()) {
3992 return "[".concat(componentType.descriptorString());
3993 } else if (isHidden()) {
3994 String name = getName();
3995 int index = name.indexOf('/');
3996 return new StringBuilder(name.length() + 2)
3997 .append('L')
3998 .append(name.substring(0, index).replace('.', '/'))
3999 .append('.')
4000 .append(name, index + 1, name.length())
4001 .append(';')
4002 .toString();
4003 } else {
4004 String name = getName().replace('.', '/');
4005 return StringConcatHelper.concat("L", name, ";");
4006 }
4007 }
4008
4009 /**
4010 * Returns the component type of this {@code Class}, if it describes
4011 * an array type, or {@code null} otherwise.
4012 *
4013 * @implSpec
4014 * Equivalent to {@link Class#getComponentType()}.
4015 *
4016 * @return a {@code Class} describing the component type, or {@code null}
4017 * if this {@code Class} does not describe an array type
4018 * @since 12
4019 */
4020 @Override
4021 public Class<?> componentType() {
4022 return getComponentType();
4023 }
4024
4025 /**
4026 * Returns a {@code Class} for an array type whose component type
4027 * is described by this {@linkplain Class}.
4028 *
4029 * @throws UnsupportedOperationException if this component type is {@linkplain
4030 * Void#TYPE void} or if the number of dimensions of the resulting array
4031 * type would exceed 255.
4032 * @return a {@code Class} describing the array type
4033 * @jvms 4.3.2 Field Descriptors
4034 * @jvms 4.4.1 The {@code CONSTANT_Class_info} Structure
4035 * @since 12
4036 */
4037 @Override
4038 public Class<?> arrayType() {
4039 try {
4040 return Array.newInstance(this, 0).getClass();
4041 } catch (IllegalArgumentException iae) {
4042 throw new UnsupportedOperationException(iae);
4043 }
4044 }
4045
4046 /**
4047 * Returns a nominal descriptor for this instance, if one can be
4048 * constructed, or an empty {@link Optional} if one cannot be.
4049 *
4050 * @return An {@link Optional} containing the resulting nominal descriptor,
4051 * or an empty {@link Optional} if one cannot be constructed.
4052 * @since 12
4053 */
4054 @Override
4055 public Optional<ClassDesc> describeConstable() {
4056 Class<?> c = isArray() ? elementType() : this;
4057 return c.isHidden() ? Optional.empty()
4058 : Optional.of(ConstantUtils.classDesc(this));
4059 }
4060
4061 /**
4062 * Returns {@code true} if and only if the underlying class is a hidden class.
4063 *
4064 * @return {@code true} if and only if this class is a hidden class.
4065 *
4066 * @since 15
4067 * @see MethodHandles.Lookup#defineHiddenClass
4068 * @see Class##hiddenClasses Hidden Classes
4069 */
4070 @IntrinsicCandidate
4071 public native boolean isHidden();
4072
4073 /**
4074 * Returns an array containing {@code Class} objects representing the
4075 * direct subinterfaces or subclasses permitted to extend or
4076 * implement this class or interface if it is sealed. The order of such elements
4077 * is unspecified. The array is empty if this sealed class or interface has no
4078 * permitted subclass. If this {@code Class} object represents a primitive type,
4079 * {@code void}, an array type, or a class or interface that is not sealed,
4080 * that is {@link #isSealed()} returns {@code false}, then this method returns {@code null}.
4081 * Conversely, if {@link #isSealed()} returns {@code true}, then this method
4082 * returns a non-null value.
4083 *
4084 * For each class or interface {@code C} which is recorded as a permitted
4085 * direct subinterface or subclass of this class or interface,
4086 * this method attempts to obtain the {@code Class}
4087 * object for {@code C} (using {@linkplain #getClassLoader() the defining class
4088 * loader} of the current {@code Class} object).
4089 * The {@code Class} objects which can be obtained and which are direct
4090 * subinterfaces or subclasses of this class or interface,
4091 * are indicated by elements of the returned array. If a {@code Class} object
4092 * cannot be obtained, it is silently ignored, and not included in the result
4093 * array.
4094 *
4095 * @return an array of {@code Class} objects of the permitted subclasses of this class
4096 * or interface, or {@code null} if this class or interface is not sealed.
4097 *
4098 * @jls 8.1 Class Declarations
4099 * @jls 9.1 Interface Declarations
4100 * @since 17
4101 */
4102 public Class<?>[] getPermittedSubclasses() {
4103 Class<?>[] subClasses;
4104 if (isArray() || isPrimitive() || (subClasses = getPermittedSubclasses0()) == null) {
4105 return null;
4106 }
4107 if (subClasses.length > 0) {
4108 if (Arrays.stream(subClasses).anyMatch(c -> !isDirectSubType(c))) {
4109 subClasses = Arrays.stream(subClasses)
4110 .filter(this::isDirectSubType)
4111 .toArray(s -> new Class<?>[s]);
4112 }
4113 }
4114 return subClasses;
4115 }
4116
4117 private boolean isDirectSubType(Class<?> c) {
4118 if (isInterface()) {
4119 for (Class<?> i : c.getInterfaces(/* cloneArray */ false)) {
4120 if (i == this) {
4121 return true;
4122 }
4123 }
4124 } else {
4125 return c.getSuperclass() == this;
4126 }
4127 return false;
4128 }
4129
4130 /**
4131 * Returns {@code true} if and only if this {@code Class} object represents
4132 * a sealed class or interface. If this {@code Class} object represents a
4133 * primitive type, {@code void}, or an array type, this method returns
4134 * {@code false}. A sealed class or interface has (possibly zero) permitted
4135 * subclasses; {@link #getPermittedSubclasses()} returns a non-null but
4136 * possibly empty value for a sealed class or interface.
4137 *
4138 * @return {@code true} if and only if this {@code Class} object represents
4139 * a sealed class or interface.
4140 *
4141 * @jls 8.1 Class Declarations
4142 * @jls 9.1 Interface Declarations
4143 * @since 17
4144 */
4145 public boolean isSealed() {
4146 if (isArray() || isPrimitive()) {
4147 return false;
4148 }
4149 return getPermittedSubclasses() != null;
4150 }
4151
4152 private native Class<?>[] getPermittedSubclasses0();
4153
4154 /*
4155 * Return the class's major and minor class file version packed into an int.
4156 * The high order 16 bits contain the class's minor version. The low order
4157 * 16 bits contain the class's major version.
4158 *
4159 * If the class is an array type then the class file version of its element
4160 * type is returned. If the class is a primitive type then the latest class
4161 * file major version is returned and zero is returned for the minor version.
4162 */
4163 int getClassFileVersion() {
4164 Class<?> c = isArray() ? elementType() : this;
4165 return c.getClassFileVersion0();
4166 }
4167
4168 private native int getClassFileVersion0();
4169
4170 /**
4171 * Return the access flags as they were in the class's bytecode, including
4172 * the original setting of ACC_SUPER.
4173 *
4174 * If this {@code Class} object represents a primitive type or
4175 * void, the flags are {@code PUBLIC}, {@code ABSTRACT}, and
4176 * {@code FINAL}.
4177 * If this {@code Class} object represents an array type, return 0.
4178 */
4179 int getClassFileAccessFlags() {
4180 return classFileAccessFlags;
4181 }
4182
4183 // Validates the length of the class name and throws an exception if it exceeds the maximum allowed length.
4184 private static void validateClassNameLength(String name) throws ClassNotFoundException {
4185 if (!ModifiedUtf.isValidLengthInConstantPool(name)) {
4186 throw new ClassNotFoundException(
4187 "Class name length exceeds limit of "
4188 + ModifiedUtf.CONSTANT_POOL_UTF8_MAX_BYTES
4189 + ": " + name.substring(0,256) + "...");
4190 }
4191 }
4192
4193 // Support for "OLD" CDS workflow -- {
4194 private static final int RD_PUBLIC_METHODS = (1 << 0);
4195 private static final int RD_PUBLIC_FIELDS = (1 << 1);
4196 private static final int RD_DECLARED_CTORS = (1 << 2);
4197 private static final int RD_PUBLIC_CTORS = (1 << 3);
4198 private static final int RD_DECLARED_METHODS = (1 << 4);
4199 private static final int RD_DECLARED_PUBLIC_METHODS = (1 << 5);
4200 private static final int RD_DECLARED_FIELDS = (1 << 6);
4201 private static final int RD_DECLARED_PUBLIC_FIELDS = (1 << 7);
4202 private static final int RD_DECLARED_INTERFACES = (1 << 8);
4203 private static final int RD_DECLARED_SIMPLE_NAME = (1 << 9);
4204 private static final int RD_DECLARED_CANONICAL_NAME = (1 << 10);
4205 private static final int CLS_NAME = (1 << 10);
4206
4207
4208 private int encodeReflectionData() {
4209 int flags = CLS_NAME;
4210 if (reflectionData != null) {
4211 flags = (reflectionData.publicMethods != null ? RD_PUBLIC_METHODS : 0) |
4212 (reflectionData.publicFields != null ? RD_PUBLIC_FIELDS : 0) |
4213 (reflectionData.declaredConstructors != null ? RD_DECLARED_CTORS : 0) |
4214 (reflectionData.publicConstructors != null ? RD_PUBLIC_CTORS : 0) |
4215 (reflectionData.declaredMethods != null ? RD_DECLARED_METHODS : 0) |
4216 (reflectionData.declaredPublicMethods != null ? RD_DECLARED_PUBLIC_METHODS : 0) |
4217 (reflectionData.declaredFields != null ? RD_DECLARED_FIELDS : 0) |
4218 (reflectionData.declaredPublicFields != null ? RD_DECLARED_PUBLIC_FIELDS : 0) |
4219 (reflectionData.interfaces != null ? RD_DECLARED_INTERFACES : 0) |
4220 (reflectionData.simpleName != null ? RD_DECLARED_SIMPLE_NAME : 0) |
4221 (reflectionData.canonicalName != null ? RD_DECLARED_CANONICAL_NAME : 0);
4222 }
4223 return flags;
4224 }
4225 private void generateReflectionData(int flags) {
4226 if ((flags & CLS_NAME ) != 0) { getName(); } // String name
4227 if ((flags & RD_PUBLIC_METHODS ) != 0) { privateGetPublicMethods(); } // Method[] publicMethods;
4228 if ((flags & RD_PUBLIC_FIELDS ) != 0) { privateGetPublicFields(); } // Field[] publicFields;
4229 if ((flags & RD_DECLARED_CTORS ) != 0) { privateGetDeclaredConstructors(false); } // Constructor<T>[] declaredConstructors;
4230 if ((flags & RD_PUBLIC_CTORS ) != 0) { privateGetDeclaredConstructors(true); } // Constructor<T>[] publicConstructors;
4231 if ((flags & RD_DECLARED_METHODS ) != 0) { privateGetDeclaredMethods(false); } // Method[] declaredMethods;
4232 if ((flags & RD_DECLARED_PUBLIC_METHODS) != 0) { privateGetDeclaredMethods(true); } // Method[] declaredPublicMethods;
4233 if ((flags & RD_DECLARED_FIELDS ) != 0) { privateGetDeclaredFields(false); } // Field[] declaredFields;
4234 if ((flags & RD_DECLARED_PUBLIC_FIELDS ) != 0) { privateGetDeclaredFields(true); } // Field[] declaredPublicFields;
4235 if ((flags & RD_DECLARED_INTERFACES ) != 0) { getInterfaces(false); } // Class<?>[] interfaces;
4236 if ((flags & RD_DECLARED_SIMPLE_NAME ) != 0) { getSimpleName(); } // String simpleName;
4237 if ((flags & RD_DECLARED_CANONICAL_NAME) != 0) { getCanonicalName(); } // String canonicalName;
4238 }
4239
4240 // -- }
4241 }