1 /*
2 * Copyright (c) 1994, 2019, 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.invoke.TypeDescriptor;
31 import java.lang.module.ModuleReader;
32 import java.lang.ref.SoftReference;
33 import java.io.IOException;
34 import java.io.InputStream;
35 import java.io.ObjectStreamField;
36 import java.lang.reflect.AnnotatedElement;
37 import java.lang.reflect.AnnotatedType;
38 import java.lang.reflect.Array;
39 import java.lang.reflect.Constructor;
40 import java.lang.reflect.Executable;
41 import java.lang.reflect.Field;
42 import java.lang.reflect.GenericArrayType;
43 import java.lang.reflect.GenericDeclaration;
44 import java.lang.reflect.InvocationTargetException;
45 import java.lang.reflect.Member;
46 import java.lang.reflect.Method;
47 import java.lang.reflect.Modifier;
48 import java.lang.reflect.Proxy;
49 import java.lang.reflect.Type;
50 import java.lang.reflect.TypeVariable;
51 import java.lang.constant.Constable;
52 import java.net.URL;
53 import java.security.AccessController;
54 import java.security.PrivilegedAction;
55 import java.util.ArrayList;
56 import java.util.Arrays;
57 import java.util.Collection;
58 import java.util.HashMap;
59 import java.util.LinkedHashMap;
60 import java.util.LinkedHashSet;
61 import java.util.List;
62 import java.util.Map;
63 import java.util.Objects;
64 import java.util.Optional;
65 import java.util.StringJoiner;
66 import java.util.stream.Stream;
67 import java.util.stream.Collectors;
68
69 import jdk.internal.HotSpotIntrinsicCandidate;
70 import jdk.internal.loader.BootLoader;
71 import jdk.internal.loader.BuiltinClassLoader;
72 import jdk.internal.misc.Unsafe;
73 import jdk.internal.module.Resources;
74 import jdk.internal.reflect.CallerSensitive;
75 import jdk.internal.reflect.ConstantPool;
76 import jdk.internal.reflect.Reflection;
77 import jdk.internal.reflect.ReflectionFactory;
78 import jdk.internal.vm.annotation.ForceInline;
79 import sun.invoke.util.Wrapper;
80 import sun.reflect.generics.factory.CoreReflectionFactory;
81 import sun.reflect.generics.factory.GenericsFactory;
82 import sun.reflect.generics.repository.ClassRepository;
83 import sun.reflect.generics.repository.MethodRepository;
84 import sun.reflect.generics.repository.ConstructorRepository;
85 import sun.reflect.generics.scope.ClassScope;
86 import sun.security.util.SecurityConstants;
87 import sun.reflect.annotation.*;
88 import sun.reflect.misc.ReflectUtil;
89
90 /**
91 * Instances of the class {@code Class} represent classes and interfaces
92 * in a running Java application. An enum type is a kind of class and an
93 * annotation type is a kind of interface. Every array also
94 * belongs to a class that is reflected as a {@code Class} object
95 * that is shared by all arrays with the same element type and number
96 * of dimensions. The primitive Java types ({@code boolean},
97 * {@code byte}, {@code char}, {@code short},
98 * {@code int}, {@code long}, {@code float}, and
99 * {@code double}), and the keyword {@code void} are also
100 * represented as {@code Class} objects.
101 *
102 * <p> {@code Class} has no public constructor. Instead a {@code Class}
103 * object is constructed automatically by the Java Virtual Machine
104 * when a class loader invokes one of the
105 * {@link ClassLoader#defineClass(String,byte[], int,int) defineClass} methods
106 * and passes the bytes of a {@code class} file.
107 *
108 * <p> The methods of class {@code Class} expose many characteristics of a
109 * class or interface. Most characteristics are derived from the {@code class}
110 * file that the class loader passed to the Java Virtual Machine. A few
111 * characteristics are determined by the class loading environment at run time,
112 * such as the module returned by {@link #getModule() getModule()}.
113 *
114 * <p> Some methods of class {@code Class} expose whether the declaration of
115 * a class or interface in Java source code was <em>enclosed</em> within
116 * another declaration. Other methods describe how a class or interface
117 * is situated in a <em>nest</em>. A <a id="nest">nest</a> is a set of
118 * classes and interfaces, in the same run-time package, that
119 * allow mutual access to their {@code private} members.
120 * The classes and interfaces are known as <em>nestmates</em>.
121 * One nestmate acts as the
122 * <em>nest host</em>, and enumerates the other nestmates which
123 * belong to the nest; each of them in turn records it as the nest host.
124 * The classes and interfaces which belong to a nest, including its host, are
125 * determined when
126 * {@code class} files are generated, for example, a Java compiler
127 * will typically record a top-level class as the host of a nest where the
128 * other members are the classes and interfaces whose declarations are
129 * enclosed within the top-level class declaration.
130 *
131 * <p> The following example uses a {@code Class} object to print the
132 * class name of an object:
133 *
134 * <blockquote><pre>
135 * void printClassName(Object obj) {
136 * System.out.println("The class of " + obj +
137 * " is " + obj.getClass().getName());
138 * }
139 * </pre></blockquote>
140 *
141 * <p> It is also possible to get the {@code Class} object for a named
142 * type (or for void) using a class literal. See Section 15.8.2 of
143 * <cite>The Java™ Language Specification</cite>.
144 * For example:
145 *
146 * <blockquote>
147 * {@code System.out.println("The name of class Foo is: "+Foo.class.getName());}
148 * </blockquote>
149 *
150 * @param <T> the type of the class modeled by this {@code Class}
151 * object. For example, the type of {@code String.class} is {@code
152 * Class<String>}. Use {@code Class<?>} if the class being modeled is
153 * unknown.
154 *
155 * @author unascribed
156 * @see java.lang.ClassLoader#defineClass(byte[], int, int)
157 * @since 1.0
158 */
159 public final class Class<T> implements java.io.Serializable,
160 GenericDeclaration,
161 Type,
162 AnnotatedElement,
163 TypeDescriptor.OfField<Class<?>>,
164 Constable {
165 private static final int ANNOTATION= 0x00002000;
166 private static final int ENUM = 0x00004000;
167 private static final int SYNTHETIC = 0x00001000;
168
169 private static native void registerNatives();
170 static {
171 registerNatives();
172 }
173
174 /*
175 * Private constructor. Only the Java Virtual Machine creates Class objects.
176 * This constructor is not used and prevents the default constructor being
177 * generated.
178 */
179 private Class(ClassLoader loader, Class<?> arrayComponentType) {
180 // Initialize final field for classLoader. The initialization value of non-null
181 // prevents future JIT optimizations from assuming this final field is null.
182 classLoader = loader;
183 componentType = arrayComponentType;
184 }
185
186 /**
187 * Converts the object to a string. The string representation is the
188 * string "class" or "interface", followed by a space, and then by the
189 * fully qualified name of the class in the format returned by
190 * {@code getName}. If this {@code Class} object represents a
191 * primitive type, this method returns the name of the primitive type. If
192 * this {@code Class} object represents void this method returns
193 * "void". If this {@code Class} object represents an array type,
194 * this method returns "class " followed by {@code getName}.
195 *
196 * @return a string representation of this class object.
197 */
198 public String toString() {
199 return (isInterface() ? "interface " : (isPrimitive() ? "" : "class "))
200 + getName();
201 }
202
203 /**
204 * Returns a string describing this {@code Class}, including
205 * information about modifiers and type parameters.
206 *
207 * The string is formatted as a list of type modifiers, if any,
208 * followed by the kind of type (empty string for primitive types
209 * and {@code class}, {@code enum}, {@code interface}, or
210 * <code>@</code>{@code interface}, as appropriate), followed
211 * by the type's name, followed by an angle-bracketed
212 * comma-separated list of the type's type parameters, if any,
213 * including informative bounds on the type parameters, if any.
214 *
215 * A space is used to separate modifiers from one another and to
216 * separate any modifiers from the kind of type. The modifiers
217 * occur in canonical order. If there are no type parameters, the
218 * type parameter list is elided.
219 *
220 * For an array type, the string starts with the type name,
221 * followed by an angle-bracketed comma-separated list of the
222 * type's type parameters, if any, followed by a sequence of
223 * {@code []} characters, one set of brackets per dimension of
224 * the array.
225 *
226 * <p>Note that since information about the runtime representation
227 * of a type is being generated, modifiers not present on the
228 * originating source code or illegal on the originating source
229 * code may be present.
230 *
231 * @return a string describing this {@code Class}, including
232 * information about modifiers and type parameters
233 *
234 * @since 1.8
235 */
236 public String toGenericString() {
237 if (isPrimitive()) {
238 return toString();
239 } else {
240 StringBuilder sb = new StringBuilder();
241 Class<?> component = this;
242 int arrayDepth = 0;
243
244 if (isArray()) {
245 do {
246 arrayDepth++;
247 component = component.getComponentType();
248 } while (component.isArray());
249 sb.append(component.getName());
250 } else {
251 // Class modifiers are a superset of interface modifiers
252 int modifiers = getModifiers() & Modifier.classModifiers();
253 if (modifiers != 0) {
254 sb.append(Modifier.toString(modifiers));
255 sb.append(' ');
256 }
257
258 if (isAnnotation()) {
259 sb.append('@');
260 }
261 if (isInterface()) { // Note: all annotation types are interfaces
262 sb.append("interface");
263 } else {
264 if (isEnum())
265 sb.append("enum");
266 else
267 sb.append("class");
268 }
269 sb.append(' ');
270 sb.append(getName());
271 }
272
273 TypeVariable<?>[] typeparms = component.getTypeParameters();
274 if (typeparms.length > 0) {
275 sb.append(Arrays.stream(typeparms)
276 .map(Class::typeVarBounds)
277 .collect(Collectors.joining(",", "<", ">")));
278 }
279
280 if (arrayDepth > 0) sb.append("[]".repeat(arrayDepth));
281
282 return sb.toString();
283 }
284 }
285
286 static String typeVarBounds(TypeVariable<?> typeVar) {
287 Type[] bounds = typeVar.getBounds();
288 if (bounds.length == 1 && bounds[0].equals(Object.class)) {
289 return typeVar.getName();
290 } else {
291 return typeVar.getName() + " extends " +
292 Arrays.stream(bounds)
293 .map(Type::getTypeName)
294 .collect(Collectors.joining(" & "));
295 }
296 }
297
298 /**
299 * Returns the {@code Class} object associated with the class or
300 * interface with the given string name. Invoking this method is
301 * equivalent to:
302 *
303 * <blockquote>
304 * {@code Class.forName(className, true, currentLoader)}
305 * </blockquote>
306 *
307 * where {@code currentLoader} denotes the defining class loader of
308 * the current class.
309 *
310 * <p> For example, the following code fragment returns the
311 * runtime {@code Class} descriptor for the class named
312 * {@code java.lang.Thread}:
313 *
314 * <blockquote>
315 * {@code Class t = Class.forName("java.lang.Thread")}
316 * </blockquote>
317 * <p>
318 * A call to {@code forName("X")} causes the class named
319 * {@code X} to be initialized.
320 *
321 * @param className the fully qualified name of the desired class.
322 * @return the {@code Class} object for the class with the
323 * specified name.
324 * @throws LinkageError if the linkage fails
325 * @throws ExceptionInInitializerError if the initialization provoked
326 * by this method fails
327 * @throws ClassNotFoundException if the class cannot be located
328 *
329 * @jls 12.2 Loading of Classes and Interfaces
330 * @jls 12.3 Linking of Classes and Interfaces
331 * @jls 12.4 Initialization of Classes and Interfaces
332 */
333 @CallerSensitive
334 public static Class<?> forName(String className)
335 throws ClassNotFoundException {
336 Class<?> caller = Reflection.getCallerClass();
337 return forName0(className, true, ClassLoader.getClassLoader(caller), caller);
338 }
339
340
341 /**
342 * Returns the {@code Class} object associated with the class or
343 * interface with the given string name, using the given class loader.
344 * Given the fully qualified name for a class or interface (in the same
345 * format returned by {@code getName}) this method attempts to
346 * locate and load the class or interface. The specified class
347 * loader is used to load the class or interface. If the parameter
348 * {@code loader} is null, the class is loaded through the bootstrap
349 * class loader. The class is initialized only if the
350 * {@code initialize} parameter is {@code true} and if it has
351 * not been initialized earlier.
352 *
353 * <p> If {@code name} denotes a primitive type or void, an attempt
354 * will be made to locate a user-defined class in the unnamed package whose
355 * name is {@code name}. Therefore, this method cannot be used to
356 * obtain any of the {@code Class} objects representing primitive
357 * types or void.
358 *
359 * <p> If {@code name} denotes an array class, the component type of
360 * the array class is loaded but not initialized.
361 *
362 * <p> For example, in an instance method the expression:
363 *
364 * <blockquote>
365 * {@code Class.forName("Foo")}
366 * </blockquote>
367 *
368 * is equivalent to:
369 *
370 * <blockquote>
371 * {@code Class.forName("Foo", true, this.getClass().getClassLoader())}
372 * </blockquote>
373 *
374 * Note that this method throws errors related to loading, linking or
375 * initializing as specified in Sections 12.2, 12.3 and 12.4 of <em>The
376 * Java Language Specification</em>.
377 * Note that this method does not check whether the requested class
378 * is accessible to its caller.
379 *
380 * @param name fully qualified name of the desired class
381 * @param initialize if {@code true} the class will be initialized (which implies linking).
382 * See Section 12.4 of <em>The Java Language Specification</em>.
383 * @param loader class loader from which the class must be loaded
384 * @return class object representing the desired class
385 *
386 * @throws LinkageError if the linkage fails
387 * @throws ExceptionInInitializerError if the initialization provoked
388 * by this method fails
389 * @throws ClassNotFoundException if the class cannot be located by
390 * the specified class loader
391 * @throws SecurityException
392 * if a security manager is present, and the {@code loader} is
393 * {@code null}, and the caller's class loader is not
394 * {@code null}, and the caller does not have the
395 * {@link RuntimePermission}{@code ("getClassLoader")}
396 *
397 * @see java.lang.Class#forName(String)
398 * @see java.lang.ClassLoader
399 *
400 * @jls 12.2 Loading of Classes and Interfaces
401 * @jls 12.3 Linking of Classes and Interfaces
402 * @jls 12.4 Initialization of Classes and Interfaces
403 * @since 1.2
404 */
405 @CallerSensitive
406 public static Class<?> forName(String name, boolean initialize,
407 ClassLoader loader)
408 throws ClassNotFoundException
409 {
410 Class<?> caller = null;
411 SecurityManager sm = System.getSecurityManager();
412 if (sm != null) {
413 // Reflective call to get caller class is only needed if a security manager
414 // is present. Avoid the overhead of making this call otherwise.
415 caller = Reflection.getCallerClass();
416 if (loader == null) {
417 ClassLoader ccl = ClassLoader.getClassLoader(caller);
418 if (ccl != null) {
419 sm.checkPermission(
420 SecurityConstants.GET_CLASSLOADER_PERMISSION);
421 }
422 }
423 }
424 return forName0(name, initialize, loader, caller);
425 }
426
427 /** Called after security check for system loader access checks have been made. */
428 private static native Class<?> forName0(String name, boolean initialize,
429 ClassLoader loader,
430 Class<?> caller)
431 throws ClassNotFoundException;
432
433
434 /**
435 * Returns the {@code Class} with the given <a href="ClassLoader.html#binary-name">
436 * binary name</a> in the given module.
437 *
438 * <p> This method attempts to locate and load the class or interface.
439 * It does not link the class, and does not run the class initializer.
440 * If the class is not found, this method returns {@code null}. </p>
441 *
442 * <p> If the class loader of the given module defines other modules and
443 * the given name is a class defined in a different module, this method
444 * returns {@code null} after the class is loaded. </p>
445 *
446 * <p> This method does not check whether the requested class is
447 * accessible to its caller. </p>
448 *
449 * @apiNote
450 * This method returns {@code null} on failure rather than
451 * throwing a {@link ClassNotFoundException}, as is done by
452 * the {@link #forName(String, boolean, ClassLoader)} method.
453 * The security check is a stack-based permission check if the caller
454 * loads a class in another module.
455 *
456 * @param module A module
457 * @param name The <a href="ClassLoader.html#binary-name">binary name</a>
458 * of the class
459 * @return {@code Class} object of the given name defined in the given module;
460 * {@code null} if not found.
461 *
462 * @throws NullPointerException if the given module or name is {@code null}
463 *
464 * @throws LinkageError if the linkage fails
465 *
466 * @throws SecurityException
467 * <ul>
468 * <li> if the caller is not the specified module and
469 * {@code RuntimePermission("getClassLoader")} permission is denied; or</li>
470 * <li> access to the module content is denied. For example,
471 * permission check will be performed when a class loader calls
472 * {@link ModuleReader#open(String)} to read the bytes of a class file
473 * in a module.</li>
474 * </ul>
475 *
476 * @jls 12.2 Loading of Classes and Interfaces
477 * @jls 12.3 Linking of Classes and Interfaces
478 * @since 9
479 * @spec JPMS
480 */
481 @CallerSensitive
482 public static Class<?> forName(Module module, String name) {
483 Objects.requireNonNull(module);
484 Objects.requireNonNull(name);
485
486 ClassLoader cl;
487 SecurityManager sm = System.getSecurityManager();
488 if (sm != null) {
489 Class<?> caller = Reflection.getCallerClass();
490 if (caller != null && caller.getModule() != module) {
491 // if caller is null, Class.forName is the last java frame on the stack.
492 // java.base has all permissions
493 sm.checkPermission(SecurityConstants.GET_CLASSLOADER_PERMISSION);
494 }
495 PrivilegedAction<ClassLoader> pa = module::getClassLoader;
496 cl = AccessController.doPrivileged(pa);
497 } else {
498 cl = module.getClassLoader();
499 }
500
501 if (cl != null) {
502 return cl.loadClass(module, name);
503 } else {
504 return BootLoader.loadClass(module, name);
505 }
506 }
507
508 /**
509 * Creates a new instance of the class represented by this {@code Class}
510 * object. The class is instantiated as if by a {@code new}
511 * expression with an empty argument list. The class is initialized if it
512 * has not already been initialized.
513 *
514 * @deprecated This method propagates any exception thrown by the
515 * nullary constructor, including a checked exception. Use of
516 * this method effectively bypasses the compile-time exception
517 * checking that would otherwise be performed by the compiler.
518 * The {@link
519 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
520 * Constructor.newInstance} method avoids this problem by wrapping
521 * any exception thrown by the constructor in a (checked) {@link
522 * java.lang.reflect.InvocationTargetException}.
523 *
524 * <p>The call
525 *
526 * <pre>{@code
527 * clazz.newInstance()
528 * }</pre>
529 *
530 * can be replaced by
531 *
532 * <pre>{@code
533 * clazz.getDeclaredConstructor().newInstance()
534 * }</pre>
535 *
536 * The latter sequence of calls is inferred to be able to throw
537 * the additional exception types {@link
538 * InvocationTargetException} and {@link
539 * NoSuchMethodException}. Both of these exception types are
540 * subclasses of {@link ReflectiveOperationException}.
541 *
542 * @return a newly allocated instance of the class represented by this
543 * object.
544 * @throws IllegalAccessException if the class or its nullary
545 * constructor is not accessible.
546 * @throws InstantiationException
547 * if this {@code Class} represents an abstract class,
548 * an interface, an array class, a primitive type, or void;
549 * or if the class has no nullary constructor;
550 * or if the instantiation fails for some other reason.
551 * @throws ExceptionInInitializerError if the initialization
552 * provoked by this method fails.
553 * @throws SecurityException
554 * If a security manager, <i>s</i>, is present and
555 * the caller's class loader is not the same as or an
556 * ancestor of the class loader for the current class and
557 * invocation of {@link SecurityManager#checkPackageAccess
558 * s.checkPackageAccess()} denies access to the package
559 * of this class.
560 */
561 @CallerSensitive
562 @Deprecated(since="9")
563 public T newInstance()
564 throws InstantiationException, IllegalAccessException
565 {
566 SecurityManager sm = System.getSecurityManager();
567 if (sm != null) {
568 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false);
569 }
570
571 // Constructor lookup
572 Constructor<T> tmpConstructor = cachedConstructor;
573 if (tmpConstructor == null) {
574 if (this == Class.class) {
575 throw new IllegalAccessException(
576 "Can not call newInstance() on the Class for java.lang.Class"
577 );
578 }
579 try {
580 Class<?>[] empty = {};
581 final Constructor<T> c = getReflectionFactory().copyConstructor(
582 getConstructor0(empty, Member.DECLARED));
583 // Disable accessibility checks on the constructor
584 // access check is done with the true caller
585 java.security.AccessController.doPrivileged(
586 new java.security.PrivilegedAction<>() {
587 public Void run() {
588 c.setAccessible(true);
589 return null;
590 }
591 });
592 cachedConstructor = tmpConstructor = c;
593 } catch (NoSuchMethodException e) {
594 throw (InstantiationException)
595 new InstantiationException(getName()).initCause(e);
596 }
597 }
598
599 try {
600 Class<?> caller = Reflection.getCallerClass();
601 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
602 } catch (InvocationTargetException e) {
603 Unsafe.getUnsafe().throwException(e.getTargetException());
604 // Not reached
605 return null;
606 }
607 }
608
609 private transient volatile Constructor<T> cachedConstructor;
610
611 /**
612 * Determines if the specified {@code Object} is assignment-compatible
613 * with the object represented by this {@code Class}. This method is
614 * the dynamic equivalent of the Java language {@code instanceof}
615 * operator. The method returns {@code true} if the specified
616 * {@code Object} argument is non-null and can be cast to the
617 * reference type represented by this {@code Class} object without
618 * raising a {@code ClassCastException.} It returns {@code false}
619 * otherwise.
620 *
621 * <p> Specifically, if this {@code Class} object represents a
622 * declared class, this method returns {@code true} if the specified
623 * {@code Object} argument is an instance of the represented class (or
624 * of any of its subclasses); it returns {@code false} otherwise. If
625 * this {@code Class} object represents an array class, this method
626 * returns {@code true} if the specified {@code Object} argument
627 * can be converted to an object of the array class by an identity
628 * conversion or by a widening reference conversion; it returns
629 * {@code false} otherwise. If this {@code Class} object
630 * represents an interface, this method returns {@code true} if the
631 * class or any superclass of the specified {@code Object} argument
632 * implements this interface; it returns {@code false} otherwise. If
633 * this {@code Class} object represents a primitive type, this method
634 * returns {@code false}.
635 *
636 * @param obj the object to check
637 * @return true if {@code obj} is an instance of this class
638 *
639 * @since 1.1
640 */
641 @HotSpotIntrinsicCandidate
642 public native boolean isInstance(Object obj);
643
644
645 /**
646 * Determines if the class or interface represented by this
647 * {@code Class} object is either the same as, or is a superclass or
648 * superinterface of, the class or interface represented by the specified
649 * {@code Class} parameter. It returns {@code true} if so;
650 * otherwise it returns {@code false}. If this {@code Class}
651 * object represents a primitive type, this method returns
652 * {@code true} if the specified {@code Class} parameter is
653 * exactly this {@code Class} object; otherwise it returns
654 * {@code false}.
655 *
656 * <p> Specifically, this method tests whether the type represented by the
657 * specified {@code Class} parameter can be converted to the type
658 * represented by this {@code Class} object via an identity conversion
659 * or via a widening reference conversion. See <em>The Java Language
660 * Specification</em>, sections 5.1.1 and 5.1.4 , for details.
661 *
662 * @param cls the {@code Class} object to be checked
663 * @return the {@code boolean} value indicating whether objects of the
664 * type {@code cls} can be assigned to objects of this class
665 * @throws NullPointerException if the specified Class parameter is
666 * null.
667 * @since 1.1
668 */
669 @HotSpotIntrinsicCandidate
670 public native boolean isAssignableFrom(Class<?> cls);
671
672
673 /**
674 * Determines if the specified {@code Class} object represents an
675 * interface type.
676 *
677 * @return {@code true} if this object represents an interface;
678 * {@code false} otherwise.
679 */
680 @HotSpotIntrinsicCandidate
681 public native boolean isInterface();
682
683
684 /**
685 * Determines if this {@code Class} object represents an array class.
686 *
687 * @return {@code true} if this object represents an array class;
688 * {@code false} otherwise.
689 * @since 1.1
690 */
691 @HotSpotIntrinsicCandidate
692 public native boolean isArray();
693
694
695 /**
696 * Determines if the specified {@code Class} object represents a
697 * primitive type.
698 *
699 * <p> There are nine predefined {@code Class} objects to represent
700 * the eight primitive types and void. These are created by the Java
701 * Virtual Machine, and have the same names as the primitive types that
702 * they represent, namely {@code boolean}, {@code byte},
703 * {@code char}, {@code short}, {@code int},
704 * {@code long}, {@code float}, and {@code double}.
705 *
706 * <p> These objects may only be accessed via the following public static
707 * final variables, and are the only {@code Class} objects for which
708 * this method returns {@code true}.
709 *
710 * @return true if and only if this class represents a primitive type
711 *
712 * @see java.lang.Boolean#TYPE
713 * @see java.lang.Character#TYPE
714 * @see java.lang.Byte#TYPE
715 * @see java.lang.Short#TYPE
716 * @see java.lang.Integer#TYPE
717 * @see java.lang.Long#TYPE
718 * @see java.lang.Float#TYPE
719 * @see java.lang.Double#TYPE
720 * @see java.lang.Void#TYPE
721 * @since 1.1
722 */
723 @HotSpotIntrinsicCandidate
724 public native boolean isPrimitive();
725
726 /**
727 * Returns true if this {@code Class} object represents an annotation
728 * type. Note that if this method returns true, {@link #isInterface()}
729 * would also return true, as all annotation types are also interfaces.
730 *
731 * @return {@code true} if this class object represents an annotation
732 * type; {@code false} otherwise
733 * @since 1.5
734 */
735 public boolean isAnnotation() {
736 return (getModifiers() & ANNOTATION) != 0;
737 }
738
739 /**
740 * Returns {@code true} if this class is a synthetic class;
741 * returns {@code false} otherwise.
742 * @return {@code true} if and only if this class is a synthetic class as
743 * defined by the Java Language Specification.
744 * @jls 13.1 The Form of a Binary
745 * @since 1.5
746 */
747 public boolean isSynthetic() {
748 return (getModifiers() & SYNTHETIC) != 0;
749 }
750
751 /**
752 * Returns the name of the entity (class, interface, array class,
753 * primitive type, or void) represented by this {@code Class} object,
754 * as a {@code String}.
755 *
756 * <p> If this class object represents a reference type that is not an
757 * array type then the binary name of the class is returned, as specified
758 * by
759 * <cite>The Java™ Language Specification</cite>.
760 *
761 * <p> If this class object represents a primitive type or void, then the
762 * name returned is a {@code String} equal to the Java language
763 * keyword corresponding to the primitive type or void.
764 *
765 * <p> If this class object represents a class of arrays, then the internal
766 * form of the name consists of the name of the element type preceded by
767 * one or more '{@code [}' characters representing the depth of the array
768 * nesting. The encoding of element type names is as follows:
769 *
770 * <blockquote><table class="striped">
771 * <caption style="display:none">Element types and encodings</caption>
772 * <thead>
773 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
774 * </thead>
775 * <tbody style="text-align:left">
776 * <tr><th scope="row"> boolean <td style="text-align:center"> Z
777 * <tr><th scope="row"> byte <td style="text-align:center"> B
778 * <tr><th scope="row"> char <td style="text-align:center"> C
779 * <tr><th scope="row"> class or interface
780 * <td style="text-align:center"> L<i>classname</i>;
781 * <tr><th scope="row"> double <td style="text-align:center"> D
782 * <tr><th scope="row"> float <td style="text-align:center"> F
783 * <tr><th scope="row"> int <td style="text-align:center"> I
784 * <tr><th scope="row"> long <td style="text-align:center"> J
785 * <tr><th scope="row"> short <td style="text-align:center"> S
786 * </tbody>
787 * </table></blockquote>
788 *
789 * <p> The class or interface name <i>classname</i> is the binary name of
790 * the class specified above.
791 *
792 * <p> Examples:
793 * <blockquote><pre>
794 * String.class.getName()
795 * returns "java.lang.String"
796 * byte.class.getName()
797 * returns "byte"
798 * (new Object[3]).getClass().getName()
799 * returns "[Ljava.lang.Object;"
800 * (new int[3][4][5][6][7][8][9]).getClass().getName()
801 * returns "[[[[[[[I"
802 * </pre></blockquote>
803 *
804 * @return the name of the class or interface
805 * represented by this object.
806 */
807 public String getName() {
808 String name = this.name;
809 return name != null ? name : initClassName();
810 }
811
812 // Cache the name to reduce the number of calls into the VM.
813 // This field would be set by VM itself during initClassName call.
814 private transient String name;
815 private native String initClassName();
816
817 /**
818 * Returns the class loader for the class. Some implementations may use
819 * null to represent the bootstrap class loader. This method will return
820 * null in such implementations if this class was loaded by the bootstrap
821 * class loader.
822 *
823 * <p>If this object
824 * represents a primitive type or void, null is returned.
825 *
826 * @return the class loader that loaded the class or interface
827 * represented by this object.
828 * @throws SecurityException
829 * if a security manager is present, and the caller's class loader
830 * is not {@code null} and is not the same as or an ancestor of the
831 * class loader for the class whose class loader is requested,
832 * and the caller does not have the
833 * {@link RuntimePermission}{@code ("getClassLoader")}
834 * @see java.lang.ClassLoader
835 * @see SecurityManager#checkPermission
836 * @see java.lang.RuntimePermission
837 */
838 @CallerSensitive
839 @ForceInline // to ensure Reflection.getCallerClass optimization
840 public ClassLoader getClassLoader() {
841 ClassLoader cl = getClassLoader0();
842 if (cl == null)
843 return null;
844 SecurityManager sm = System.getSecurityManager();
845 if (sm != null) {
846 ClassLoader.checkClassLoaderPermission(cl, Reflection.getCallerClass());
847 }
848 return cl;
849 }
850
851 // Package-private to allow ClassLoader access
852 ClassLoader getClassLoader0() { return classLoader; }
853
854 /**
855 * Returns the module that this class or interface is a member of.
856 *
857 * If this class represents an array type then this method returns the
858 * {@code Module} for the element type. If this class represents a
859 * primitive type or void, then the {@code Module} object for the
860 * {@code java.base} module is returned.
861 *
862 * If this class is in an unnamed module then the {@linkplain
863 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
864 * loader for this class is returned.
865 *
866 * @return the module that this class or interface is a member of
867 *
868 * @since 9
869 * @spec JPMS
870 */
871 public Module getModule() {
872 return module;
873 }
874
875 // set by VM
876 private transient Module module;
877
878 // Initialized in JVM not by private constructor
879 // This field is filtered from reflection access, i.e. getDeclaredField
880 // will throw NoSuchFieldException
881 private final ClassLoader classLoader;
882
883 /**
884 * Returns an array of {@code TypeVariable} objects that represent the
885 * type variables declared by the generic declaration represented by this
886 * {@code GenericDeclaration} object, in declaration order. Returns an
887 * array of length 0 if the underlying generic declaration declares no type
888 * variables.
889 *
890 * @return an array of {@code TypeVariable} objects that represent
891 * the type variables declared by this generic declaration
892 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
893 * signature of this generic declaration does not conform to
894 * the format specified in
895 * <cite>The Java™ Virtual Machine Specification</cite>
896 * @since 1.5
897 */
898 @SuppressWarnings("unchecked")
899 public TypeVariable<Class<T>>[] getTypeParameters() {
900 ClassRepository info = getGenericInfo();
901 if (info != null)
902 return (TypeVariable<Class<T>>[])info.getTypeParameters();
903 else
904 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
905 }
906
907
908 /**
909 * Returns the {@code Class} representing the direct superclass of the
910 * entity (class, interface, primitive type or void) represented by
911 * this {@code Class}. If this {@code Class} represents either the
912 * {@code Object} class, an interface, a primitive type, or void, then
913 * null is returned. If this object represents an array class then the
914 * {@code Class} object representing the {@code Object} class is
915 * returned.
916 *
917 * @return the direct superclass of the class represented by this object
918 */
919 @HotSpotIntrinsicCandidate
920 public native Class<? super T> getSuperclass();
921
922
923 /**
924 * Returns the {@code Type} representing the direct superclass of
925 * the entity (class, interface, primitive type or void) represented by
926 * this {@code Class}.
927 *
928 * <p>If the superclass is a parameterized type, the {@code Type}
929 * object returned must accurately reflect the actual type
930 * arguments used in the source code. The parameterized type
931 * representing the superclass is created if it had not been
932 * created before. See the declaration of {@link
933 * java.lang.reflect.ParameterizedType ParameterizedType} for the
934 * semantics of the creation process for parameterized types. If
935 * this {@code Class} represents either the {@code Object}
936 * class, an interface, a primitive type, or void, then null is
937 * returned. If this object represents an array class then the
938 * {@code Class} object representing the {@code Object} class is
939 * returned.
940 *
941 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
942 * class signature does not conform to the format specified in
943 * <cite>The Java™ Virtual Machine Specification</cite>
944 * @throws TypeNotPresentException if the generic superclass
945 * refers to a non-existent type declaration
946 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
947 * generic superclass refers to a parameterized type that cannot be
948 * instantiated for any reason
949 * @return the direct superclass of the class represented by this object
950 * @since 1.5
951 */
952 public Type getGenericSuperclass() {
953 ClassRepository info = getGenericInfo();
954 if (info == null) {
955 return getSuperclass();
956 }
957
958 // Historical irregularity:
959 // Generic signature marks interfaces with superclass = Object
960 // but this API returns null for interfaces
961 if (isInterface()) {
962 return null;
963 }
964
965 return info.getSuperclass();
966 }
967
968 /**
969 * Gets the package of this class.
970 *
971 * <p>If this class represents an array type, a primitive type or void,
972 * this method returns {@code null}.
973 *
974 * @return the package of this class.
975 * @revised 9
976 * @spec JPMS
977 */
978 public Package getPackage() {
979 if (isPrimitive() || isArray()) {
980 return null;
981 }
982 ClassLoader cl = getClassLoader0();
983 return cl != null ? cl.definePackage(this)
984 : BootLoader.definePackage(this);
985 }
986
987 /**
988 * Returns the fully qualified package name.
989 *
990 * <p> If this class is a top level class, then this method returns the fully
991 * qualified name of the package that the class is a member of, or the
992 * empty string if the class is in an unnamed package.
993 *
994 * <p> If this class is a member class, then this method is equivalent to
995 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
996 * enclosing class}.
997 *
998 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
999 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1000 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1001 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1002 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1003 *
1004 * <p> If this class represents an array type then this method returns the
1005 * package name of the element type. If this class represents a primitive
1006 * type or void then the package name "{@code java.lang}" is returned.
1007 *
1008 * @return the fully qualified package name
1009 *
1010 * @since 9
1011 * @spec JPMS
1012 * @jls 6.7 Fully Qualified Names
1013 */
1014 public String getPackageName() {
1015 String pn = this.packageName;
1016 if (pn == null) {
1017 Class<?> c = this;
1018 while (c.isArray()) {
1019 c = c.getComponentType();
1020 }
1021 if (c.isPrimitive()) {
1022 pn = "java.lang";
1023 } else {
1024 String cn = c.getName();
1025 int dot = cn.lastIndexOf('.');
1026 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1027 }
1028 this.packageName = pn;
1029 }
1030 return pn;
1031 }
1032
1033 // cached package name
1034 private transient String packageName;
1035
1036 /**
1037 * Returns the interfaces directly implemented by the class or interface
1038 * represented by this object.
1039 *
1040 * <p>If this object represents a class, the return value is an array
1041 * containing objects representing all interfaces directly implemented by
1042 * the class. The order of the interface objects in the array corresponds
1043 * to the order of the interface names in the {@code implements} clause of
1044 * the declaration of the class represented by this object. For example,
1045 * given the declaration:
1046 * <blockquote>
1047 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1048 * </blockquote>
1049 * suppose the value of {@code s} is an instance of
1050 * {@code Shimmer}; the value of the expression:
1051 * <blockquote>
1052 * {@code s.getClass().getInterfaces()[0]}
1053 * </blockquote>
1054 * is the {@code Class} object that represents interface
1055 * {@code FloorWax}; and the value of:
1056 * <blockquote>
1057 * {@code s.getClass().getInterfaces()[1]}
1058 * </blockquote>
1059 * is the {@code Class} object that represents interface
1060 * {@code DessertTopping}.
1061 *
1062 * <p>If this object represents an interface, the array contains objects
1063 * representing all interfaces directly extended by the interface. The
1064 * order of the interface objects in the array corresponds to the order of
1065 * the interface names in the {@code extends} clause of the declaration of
1066 * the interface represented by this object.
1067 *
1068 * <p>If this object represents a class or interface that implements no
1069 * interfaces, the method returns an array of length 0.
1070 *
1071 * <p>If this object represents a primitive type or void, the method
1072 * returns an array of length 0.
1073 *
1074 * <p>If this {@code Class} object represents an array type, the
1075 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1076 * returned in that order.
1077 *
1078 * @return an array of interfaces directly implemented by this class
1079 */
1080 public Class<?>[] getInterfaces() {
1081 // defensively copy before handing over to user code
1082 return getInterfaces(true);
1083 }
1084
1085 private Class<?>[] getInterfaces(boolean cloneArray) {
1086 ReflectionData<T> rd = reflectionData();
1087 if (rd == null) {
1088 // no cloning required
1089 return getInterfaces0();
1090 } else {
1091 Class<?>[] interfaces = rd.interfaces;
1092 if (interfaces == null) {
1093 interfaces = getInterfaces0();
1094 rd.interfaces = interfaces;
1095 }
1096 // defensively copy if requested
1097 return cloneArray ? interfaces.clone() : interfaces;
1098 }
1099 }
1100
1101 private native Class<?>[] getInterfaces0();
1102
1103 /**
1104 * Returns the {@code Type}s representing the interfaces
1105 * directly implemented by the class or interface represented by
1106 * this object.
1107 *
1108 * <p>If a superinterface is a parameterized type, the
1109 * {@code Type} object returned for it must accurately reflect
1110 * the actual type arguments used in the source code. The
1111 * parameterized type representing each superinterface is created
1112 * if it had not been created before. See the declaration of
1113 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1114 * for the semantics of the creation process for parameterized
1115 * types.
1116 *
1117 * <p>If this object represents a class, the return value is an array
1118 * containing objects representing all interfaces directly implemented by
1119 * the class. The order of the interface objects in the array corresponds
1120 * to the order of the interface names in the {@code implements} clause of
1121 * the declaration of the class represented by this object.
1122 *
1123 * <p>If this object represents an interface, the array contains objects
1124 * representing all interfaces directly extended by the interface. The
1125 * order of the interface objects in the array corresponds to the order of
1126 * the interface names in the {@code extends} clause of the declaration of
1127 * the interface represented by this object.
1128 *
1129 * <p>If this object represents a class or interface that implements no
1130 * interfaces, the method returns an array of length 0.
1131 *
1132 * <p>If this object represents a primitive type or void, the method
1133 * returns an array of length 0.
1134 *
1135 * <p>If this {@code Class} object represents an array type, the
1136 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1137 * returned in that order.
1138 *
1139 * @throws java.lang.reflect.GenericSignatureFormatError
1140 * if the generic class signature does not conform to the format
1141 * specified in
1142 * <cite>The Java™ Virtual Machine Specification</cite>
1143 * @throws TypeNotPresentException if any of the generic
1144 * superinterfaces refers to a non-existent type declaration
1145 * @throws java.lang.reflect.MalformedParameterizedTypeException
1146 * if any of the generic superinterfaces refer to a parameterized
1147 * type that cannot be instantiated for any reason
1148 * @return an array of interfaces directly implemented by this class
1149 * @since 1.5
1150 */
1151 public Type[] getGenericInterfaces() {
1152 ClassRepository info = getGenericInfo();
1153 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1154 }
1155
1156
1157 /**
1158 * Returns the {@code Class} representing the component type of an
1159 * array. If this class does not represent an array class this method
1160 * returns null.
1161 *
1162 * @return the {@code Class} representing the component type of this
1163 * class if this class is an array
1164 * @see java.lang.reflect.Array
1165 * @since 1.1
1166 */
1167 public Class<?> getComponentType() {
1168 // Only return for array types. Storage may be reused for Class for instance types.
1169 if (isArray()) {
1170 return componentType;
1171 } else {
1172 return null;
1173 }
1174 }
1175
1176 private final Class<?> componentType;
1177
1178
1179 /**
1180 * Returns the Java language modifiers for this class or interface, encoded
1181 * in an integer. The modifiers consist of the Java Virtual Machine's
1182 * constants for {@code public}, {@code protected},
1183 * {@code private}, {@code final}, {@code static},
1184 * {@code abstract} and {@code interface}; they should be decoded
1185 * using the methods of class {@code Modifier}.
1186 *
1187 * <p> If the underlying class is an array class, then its
1188 * {@code public}, {@code private} and {@code protected}
1189 * modifiers are the same as those of its component type. If this
1190 * {@code Class} represents a primitive type or void, its
1191 * {@code public} modifier is always {@code true}, and its
1192 * {@code protected} and {@code private} modifiers are always
1193 * {@code false}. If this object represents an array class, a
1194 * primitive type or void, then its {@code final} modifier is always
1195 * {@code true} and its interface modifier is always
1196 * {@code false}. The values of its other modifiers are not determined
1197 * by this specification.
1198 *
1199 * <p> The modifier encodings are defined in <em>The Java Virtual Machine
1200 * Specification</em>, table 4.1.
1201 *
1202 * @return the {@code int} representing the modifiers for this class
1203 * @see java.lang.reflect.Modifier
1204 * @since 1.1
1205 */
1206 @HotSpotIntrinsicCandidate
1207 public native int getModifiers();
1208
1209
1210 /**
1211 * Gets the signers of this class.
1212 *
1213 * @return the signers of this class, or null if there are no signers. In
1214 * particular, this method returns null if this object represents
1215 * a primitive type or void.
1216 * @since 1.1
1217 */
1218 public native Object[] getSigners();
1219
1220
1221 /**
1222 * Set the signers of this class.
1223 */
1224 native void setSigners(Object[] signers);
1225
1226
1227 /**
1228 * If this {@code Class} object represents a local or anonymous
1229 * class within a method, returns a {@link
1230 * java.lang.reflect.Method Method} object representing the
1231 * immediately enclosing method of the underlying class. Returns
1232 * {@code null} otherwise.
1233 *
1234 * In particular, this method returns {@code null} if the underlying
1235 * class is a local or anonymous class immediately enclosed by a type
1236 * declaration, instance initializer or static initializer.
1237 *
1238 * @return the immediately enclosing method of the underlying class, if
1239 * that class is a local or anonymous class; otherwise {@code null}.
1240 *
1241 * @throws SecurityException
1242 * If a security manager, <i>s</i>, is present and any of the
1243 * following conditions is met:
1244 *
1245 * <ul>
1246 *
1247 * <li> the caller's class loader is not the same as the
1248 * class loader of the enclosing class and invocation of
1249 * {@link SecurityManager#checkPermission
1250 * s.checkPermission} method with
1251 * {@code RuntimePermission("accessDeclaredMembers")}
1252 * denies access to the methods within the enclosing class
1253 *
1254 * <li> the caller's class loader is not the same as or an
1255 * ancestor of the class loader for the enclosing class and
1256 * invocation of {@link SecurityManager#checkPackageAccess
1257 * s.checkPackageAccess()} denies access to the package
1258 * of the enclosing class
1259 *
1260 * </ul>
1261 * @since 1.5
1262 */
1263 @CallerSensitive
1264 public Method getEnclosingMethod() throws SecurityException {
1265 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1266
1267 if (enclosingInfo == null)
1268 return null;
1269 else {
1270 if (!enclosingInfo.isMethod())
1271 return null;
1272
1273 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1274 getFactory());
1275 Class<?> returnType = toClass(typeInfo.getReturnType());
1276 Type [] parameterTypes = typeInfo.getParameterTypes();
1277 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1278
1279 // Convert Types to Classes; returned types *should*
1280 // be class objects since the methodDescriptor's used
1281 // don't have generics information
1282 for(int i = 0; i < parameterClasses.length; i++)
1283 parameterClasses[i] = toClass(parameterTypes[i]);
1284
1285 // Perform access check
1286 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1287 SecurityManager sm = System.getSecurityManager();
1288 if (sm != null) {
1289 enclosingCandidate.checkMemberAccess(sm, Member.DECLARED,
1290 Reflection.getCallerClass(), true);
1291 }
1292 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1293
1294 /*
1295 * Loop over all declared methods; match method name,
1296 * number of and type of parameters, *and* return
1297 * type. Matching return type is also necessary
1298 * because of covariant returns, etc.
1299 */
1300 ReflectionFactory fact = getReflectionFactory();
1301 for (Method m : candidates) {
1302 if (m.getName().equals(enclosingInfo.getName()) &&
1303 arrayContentsEq(parameterClasses,
1304 fact.getExecutableSharedParameterTypes(m))) {
1305 // finally, check return type
1306 if (m.getReturnType().equals(returnType)) {
1307 return fact.copyMethod(m);
1308 }
1309 }
1310 }
1311
1312 throw new InternalError("Enclosing method not found");
1313 }
1314 }
1315
1316 private native Object[] getEnclosingMethod0();
1317
1318 private EnclosingMethodInfo getEnclosingMethodInfo() {
1319 Object[] enclosingInfo = getEnclosingMethod0();
1320 if (enclosingInfo == null)
1321 return null;
1322 else {
1323 return new EnclosingMethodInfo(enclosingInfo);
1324 }
1325 }
1326
1327 private static final class EnclosingMethodInfo {
1328 private final Class<?> enclosingClass;
1329 private final String name;
1330 private final String descriptor;
1331
1332 static void validate(Object[] enclosingInfo) {
1333 if (enclosingInfo.length != 3)
1334 throw new InternalError("Malformed enclosing method information");
1335 try {
1336 // The array is expected to have three elements:
1337
1338 // the immediately enclosing class
1339 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1340 assert(enclosingClass != null);
1341
1342 // the immediately enclosing method or constructor's
1343 // name (can be null).
1344 String name = (String)enclosingInfo[1];
1345
1346 // the immediately enclosing method or constructor's
1347 // descriptor (null iff name is).
1348 String descriptor = (String)enclosingInfo[2];
1349 assert((name != null && descriptor != null) || name == descriptor);
1350 } catch (ClassCastException cce) {
1351 throw new InternalError("Invalid type in enclosing method information", cce);
1352 }
1353 }
1354
1355 EnclosingMethodInfo(Object[] enclosingInfo) {
1356 validate(enclosingInfo);
1357 this.enclosingClass = (Class<?>)enclosingInfo[0];
1358 this.name = (String)enclosingInfo[1];
1359 this.descriptor = (String)enclosingInfo[2];
1360 }
1361
1362 boolean isPartial() {
1363 return enclosingClass == null || name == null || descriptor == null;
1364 }
1365
1366 boolean isConstructor() { return !isPartial() && "<init>".equals(name); }
1367
1368 boolean isMethod() { return !isPartial() && !isConstructor() && !"<clinit>".equals(name); }
1369
1370 Class<?> getEnclosingClass() { return enclosingClass; }
1371
1372 String getName() { return name; }
1373
1374 String getDescriptor() { return descriptor; }
1375
1376 }
1377
1378 private static Class<?> toClass(Type o) {
1379 if (o instanceof GenericArrayType)
1380 return Array.newInstance(toClass(((GenericArrayType)o).getGenericComponentType()),
1381 0)
1382 .getClass();
1383 return (Class<?>)o;
1384 }
1385
1386 /**
1387 * If this {@code Class} object represents a local or anonymous
1388 * class within a constructor, returns a {@link
1389 * java.lang.reflect.Constructor Constructor} object representing
1390 * the immediately enclosing constructor of the underlying
1391 * class. Returns {@code null} otherwise. In particular, this
1392 * method returns {@code null} if the underlying class is a local
1393 * or anonymous class immediately enclosed by a type declaration,
1394 * instance initializer or static initializer.
1395 *
1396 * @return the immediately enclosing constructor of the underlying class, if
1397 * that class is a local or anonymous class; otherwise {@code null}.
1398 * @throws SecurityException
1399 * If a security manager, <i>s</i>, is present and any of the
1400 * following conditions is met:
1401 *
1402 * <ul>
1403 *
1404 * <li> the caller's class loader is not the same as the
1405 * class loader of the enclosing class and invocation of
1406 * {@link SecurityManager#checkPermission
1407 * s.checkPermission} method with
1408 * {@code RuntimePermission("accessDeclaredMembers")}
1409 * denies access to the constructors within the enclosing class
1410 *
1411 * <li> the caller's class loader is not the same as or an
1412 * ancestor of the class loader for the enclosing class and
1413 * invocation of {@link SecurityManager#checkPackageAccess
1414 * s.checkPackageAccess()} denies access to the package
1415 * of the enclosing class
1416 *
1417 * </ul>
1418 * @since 1.5
1419 */
1420 @CallerSensitive
1421 public Constructor<?> getEnclosingConstructor() throws SecurityException {
1422 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1423
1424 if (enclosingInfo == null)
1425 return null;
1426 else {
1427 if (!enclosingInfo.isConstructor())
1428 return null;
1429
1430 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1431 getFactory());
1432 Type [] parameterTypes = typeInfo.getParameterTypes();
1433 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1434
1435 // Convert Types to Classes; returned types *should*
1436 // be class objects since the methodDescriptor's used
1437 // don't have generics information
1438 for(int i = 0; i < parameterClasses.length; i++)
1439 parameterClasses[i] = toClass(parameterTypes[i]);
1440
1441 // Perform access check
1442 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1443 SecurityManager sm = System.getSecurityManager();
1444 if (sm != null) {
1445 enclosingCandidate.checkMemberAccess(sm, Member.DECLARED,
1446 Reflection.getCallerClass(), true);
1447 }
1448
1449 Constructor<?>[] candidates = enclosingCandidate
1450 .privateGetDeclaredConstructors(false);
1451 /*
1452 * Loop over all declared constructors; match number
1453 * of and type of parameters.
1454 */
1455 ReflectionFactory fact = getReflectionFactory();
1456 for (Constructor<?> c : candidates) {
1457 if (arrayContentsEq(parameterClasses,
1458 fact.getExecutableSharedParameterTypes(c))) {
1459 return fact.copyConstructor(c);
1460 }
1461 }
1462
1463 throw new InternalError("Enclosing constructor not found");
1464 }
1465 }
1466
1467
1468 /**
1469 * If the class or interface represented by this {@code Class} object
1470 * is a member of another class, returns the {@code Class} object
1471 * representing the class in which it was declared. This method returns
1472 * null if this class or interface is not a member of any other class. If
1473 * this {@code Class} object represents an array class, a primitive
1474 * type, or void,then this method returns null.
1475 *
1476 * @return the declaring class for this class
1477 * @throws SecurityException
1478 * If a security manager, <i>s</i>, is present and the caller's
1479 * class loader is not the same as or an ancestor of the class
1480 * loader for the declaring class and invocation of {@link
1481 * SecurityManager#checkPackageAccess s.checkPackageAccess()}
1482 * denies access to the package of the declaring class
1483 * @since 1.1
1484 */
1485 @CallerSensitive
1486 public Class<?> getDeclaringClass() throws SecurityException {
1487 final Class<?> candidate = getDeclaringClass0();
1488
1489 if (candidate != null) {
1490 SecurityManager sm = System.getSecurityManager();
1491 if (sm != null) {
1492 candidate.checkPackageAccess(sm,
1493 ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
1494 }
1495 }
1496 return candidate;
1497 }
1498
1499 private native Class<?> getDeclaringClass0();
1500
1501
1502 /**
1503 * Returns the immediately enclosing class of the underlying
1504 * class. If the underlying class is a top level class this
1505 * method returns {@code null}.
1506 * @return the immediately enclosing class of the underlying class
1507 * @throws SecurityException
1508 * If a security manager, <i>s</i>, is present and the caller's
1509 * class loader is not the same as or an ancestor of the class
1510 * loader for the enclosing class and invocation of {@link
1511 * SecurityManager#checkPackageAccess s.checkPackageAccess()}
1512 * denies access to the package of the enclosing class
1513 * @since 1.5
1514 */
1515 @CallerSensitive
1516 public Class<?> getEnclosingClass() throws SecurityException {
1517 // There are five kinds of classes (or interfaces):
1518 // a) Top level classes
1519 // b) Nested classes (static member classes)
1520 // c) Inner classes (non-static member classes)
1521 // d) Local classes (named classes declared within a method)
1522 // e) Anonymous classes
1523
1524
1525 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1526 // attribute if and only if it is a local class or an
1527 // anonymous class.
1528 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1529 Class<?> enclosingCandidate;
1530
1531 if (enclosingInfo == null) {
1532 // This is a top level or a nested class or an inner class (a, b, or c)
1533 enclosingCandidate = getDeclaringClass0();
1534 } else {
1535 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1536 // This is a local class or an anonymous class (d or e)
1537 if (enclosingClass == this || enclosingClass == null)
1538 throw new InternalError("Malformed enclosing method information");
1539 else
1540 enclosingCandidate = enclosingClass;
1541 }
1542
1543 if (enclosingCandidate != null) {
1544 SecurityManager sm = System.getSecurityManager();
1545 if (sm != null) {
1546 enclosingCandidate.checkPackageAccess(sm,
1547 ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
1548 }
1549 }
1550 return enclosingCandidate;
1551 }
1552
1553 /**
1554 * Returns the simple name of the underlying class as given in the
1555 * source code. Returns an empty string if the underlying class is
1556 * anonymous.
1557 *
1558 * <p>The simple name of an array is the simple name of the
1559 * component type with "[]" appended. In particular the simple
1560 * name of an array whose component type is anonymous is "[]".
1561 *
1562 * @return the simple name of the underlying class
1563 * @since 1.5
1564 */
1565 public String getSimpleName() {
1566 ReflectionData<T> rd = reflectionData();
1567 String simpleName = rd.simpleName;
1568 if (simpleName == null) {
1569 rd.simpleName = simpleName = getSimpleName0();
1570 }
1571 return simpleName;
1572 }
1573
1574 private String getSimpleName0() {
1575 if (isArray()) {
1576 return getComponentType().getSimpleName() + "[]";
1577 }
1578 String simpleName = getSimpleBinaryName();
1579 if (simpleName == null) { // top level class
1580 simpleName = getName();
1581 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1582 }
1583 return simpleName;
1584 }
1585
1586 /**
1587 * Return an informative string for the name of this type.
1588 *
1589 * @return an informative string for the name of this type
1590 * @since 1.8
1591 */
1592 public String getTypeName() {
1593 if (isArray()) {
1594 try {
1595 Class<?> cl = this;
1596 int dimensions = 0;
1597 do {
1598 dimensions++;
1599 cl = cl.getComponentType();
1600 } while (cl.isArray());
1601 return cl.getName() + "[]".repeat(dimensions);
1602 } catch (Throwable e) { /*FALLTHRU*/ }
1603 }
1604 return getName();
1605 }
1606
1607 /**
1608 * Returns the canonical name of the underlying class as
1609 * defined by the Java Language Specification. Returns null if
1610 * the underlying class does not have a canonical name (i.e., if
1611 * it is a local or anonymous class or an array whose component
1612 * type does not have a canonical name).
1613 * @return the canonical name of the underlying class if it exists, and
1614 * {@code null} otherwise.
1615 * @since 1.5
1616 */
1617 public String getCanonicalName() {
1618 ReflectionData<T> rd = reflectionData();
1619 String canonicalName = rd.canonicalName;
1620 if (canonicalName == null) {
1621 rd.canonicalName = canonicalName = getCanonicalName0();
1622 }
1623 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1624 }
1625
1626 private String getCanonicalName0() {
1627 if (isArray()) {
1628 String canonicalName = getComponentType().getCanonicalName();
1629 if (canonicalName != null)
1630 return canonicalName + "[]";
1631 else
1632 return ReflectionData.NULL_SENTINEL;
1633 }
1634 if (isLocalOrAnonymousClass())
1635 return ReflectionData.NULL_SENTINEL;
1636 Class<?> enclosingClass = getEnclosingClass();
1637 if (enclosingClass == null) { // top level class
1638 return getName();
1639 } else {
1640 String enclosingName = enclosingClass.getCanonicalName();
1641 if (enclosingName == null)
1642 return ReflectionData.NULL_SENTINEL;
1643 return enclosingName + "." + getSimpleName();
1644 }
1645 }
1646
1647 /**
1648 * Returns {@code true} if and only if the underlying class
1649 * is an anonymous class.
1650 *
1651 * @return {@code true} if and only if this class is an anonymous class.
1652 * @since 1.5
1653 */
1654 public boolean isAnonymousClass() {
1655 return !isArray() && isLocalOrAnonymousClass() &&
1656 getSimpleBinaryName0() == null;
1657 }
1658
1659 /**
1660 * Returns {@code true} if and only if the underlying class
1661 * is a local class.
1662 *
1663 * @return {@code true} if and only if this class is a local class.
1664 * @since 1.5
1665 */
1666 public boolean isLocalClass() {
1667 return isLocalOrAnonymousClass() &&
1668 (isArray() || getSimpleBinaryName0() != null);
1669 }
1670
1671 /**
1672 * Returns {@code true} if and only if the underlying class
1673 * is a member class.
1674 *
1675 * @return {@code true} if and only if this class is a member class.
1676 * @since 1.5
1677 */
1678 public boolean isMemberClass() {
1679 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1680 }
1681
1682 /**
1683 * Returns the "simple binary name" of the underlying class, i.e.,
1684 * the binary name without the leading enclosing class name.
1685 * Returns {@code null} if the underlying class is a top level
1686 * class.
1687 */
1688 private String getSimpleBinaryName() {
1689 if (isTopLevelClass())
1690 return null;
1691 String name = getSimpleBinaryName0();
1692 if (name == null) // anonymous class
1693 return "";
1694 return name;
1695 }
1696
1697 private native String getSimpleBinaryName0();
1698
1699 /**
1700 * Returns {@code true} if this is a top level class. Returns {@code false}
1701 * otherwise.
1702 */
1703 private boolean isTopLevelClass() {
1704 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1705 }
1706
1707 /**
1708 * Returns {@code true} if this is a local class or an anonymous
1709 * class. Returns {@code false} otherwise.
1710 */
1711 private boolean isLocalOrAnonymousClass() {
1712 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1713 // attribute if and only if it is a local class or an
1714 // anonymous class.
1715 return hasEnclosingMethodInfo();
1716 }
1717
1718 private boolean hasEnclosingMethodInfo() {
1719 Object[] enclosingInfo = getEnclosingMethod0();
1720 if (enclosingInfo != null) {
1721 EnclosingMethodInfo.validate(enclosingInfo);
1722 return true;
1723 }
1724 return false;
1725 }
1726
1727 /**
1728 * Returns an array containing {@code Class} objects representing all
1729 * the public classes and interfaces that are members of the class
1730 * represented by this {@code Class} object. This includes public
1731 * class and interface members inherited from superclasses and public class
1732 * and interface members declared by the class. This method returns an
1733 * array of length 0 if this {@code Class} object has no public member
1734 * classes or interfaces. This method also returns an array of length 0 if
1735 * this {@code Class} object represents a primitive type, an array
1736 * class, or void.
1737 *
1738 * @return the array of {@code Class} objects representing the public
1739 * members of this class
1740 * @throws SecurityException
1741 * If a security manager, <i>s</i>, is present and
1742 * the caller's class loader is not the same as or an
1743 * ancestor of the class loader for the current class and
1744 * invocation of {@link SecurityManager#checkPackageAccess
1745 * s.checkPackageAccess()} denies access to the package
1746 * of this class.
1747 *
1748 * @since 1.1
1749 */
1750 @CallerSensitive
1751 public Class<?>[] getClasses() {
1752 SecurityManager sm = System.getSecurityManager();
1753 if (sm != null) {
1754 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false);
1755 }
1756
1757 // Privileged so this implementation can look at DECLARED classes,
1758 // something the caller might not have privilege to do. The code here
1759 // is allowed to look at DECLARED classes because (1) it does not hand
1760 // out anything other than public members and (2) public member access
1761 // has already been ok'd by the SecurityManager.
1762
1763 return java.security.AccessController.doPrivileged(
1764 new java.security.PrivilegedAction<>() {
1765 public Class<?>[] run() {
1766 List<Class<?>> list = new ArrayList<>();
1767 Class<?> currentClass = Class.this;
1768 while (currentClass != null) {
1769 for (Class<?> m : currentClass.getDeclaredClasses()) {
1770 if (Modifier.isPublic(m.getModifiers())) {
1771 list.add(m);
1772 }
1773 }
1774 currentClass = currentClass.getSuperclass();
1775 }
1776 return list.toArray(new Class<?>[0]);
1777 }
1778 });
1779 }
1780
1781
1782 /**
1783 * Returns an array containing {@code Field} objects reflecting all
1784 * the accessible public fields of the class or interface represented by
1785 * this {@code Class} object.
1786 *
1787 * <p> If this {@code Class} object represents a class or interface with
1788 * no accessible public fields, then this method returns an array of length
1789 * 0.
1790 *
1791 * <p> If this {@code Class} object represents a class, then this method
1792 * returns the public fields of the class and of all its superclasses and
1793 * superinterfaces.
1794 *
1795 * <p> If this {@code Class} object represents an interface, then this
1796 * method returns the fields of the interface and of all its
1797 * superinterfaces.
1798 *
1799 * <p> If this {@code Class} object represents an array type, a primitive
1800 * type, or void, then this method returns an array of length 0.
1801 *
1802 * <p> The elements in the returned array are not sorted and are not in any
1803 * particular order.
1804 *
1805 * @return the array of {@code Field} objects representing the
1806 * public fields
1807 * @throws SecurityException
1808 * If a security manager, <i>s</i>, is present and
1809 * the caller's class loader is not the same as or an
1810 * ancestor of the class loader for the current class and
1811 * invocation of {@link SecurityManager#checkPackageAccess
1812 * s.checkPackageAccess()} denies access to the package
1813 * of this class.
1814 *
1815 * @since 1.1
1816 * @jls 8.2 Class Members
1817 * @jls 8.3 Field Declarations
1818 */
1819 @CallerSensitive
1820 public Field[] getFields() throws SecurityException {
1821 SecurityManager sm = System.getSecurityManager();
1822 if (sm != null) {
1823 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1824 }
1825 return copyFields(privateGetPublicFields());
1826 }
1827
1828
1829 /**
1830 * Returns an array containing {@code Method} objects reflecting all the
1831 * public methods of the class or interface represented by this {@code
1832 * Class} object, including those declared by the class or interface and
1833 * those inherited from superclasses and superinterfaces.
1834 *
1835 * <p> If this {@code Class} object represents an array type, then the
1836 * returned array has a {@code Method} object for each of the public
1837 * methods inherited by the array type from {@code Object}. It does not
1838 * contain a {@code Method} object for {@code clone()}.
1839 *
1840 * <p> If this {@code Class} object represents an interface then the
1841 * returned array does not contain any implicitly declared methods from
1842 * {@code Object}. Therefore, if no methods are explicitly declared in
1843 * this interface or any of its superinterfaces then the returned array
1844 * has length 0. (Note that a {@code Class} object which represents a class
1845 * always has public methods, inherited from {@code Object}.)
1846 *
1847 * <p> The returned array never contains methods with names "{@code <init>}"
1848 * or "{@code <clinit>}".
1849 *
1850 * <p> The elements in the returned array are not sorted and are not in any
1851 * particular order.
1852 *
1853 * <p> Generally, the result is computed as with the following 4 step algorithm.
1854 * Let C be the class or interface represented by this {@code Class} object:
1855 * <ol>
1856 * <li> A union of methods is composed of:
1857 * <ol type="a">
1858 * <li> C's declared public instance and static methods as returned by
1859 * {@link #getDeclaredMethods()} and filtered to include only public
1860 * methods.</li>
1861 * <li> If C is a class other than {@code Object}, then include the result
1862 * of invoking this algorithm recursively on the superclass of C.</li>
1863 * <li> Include the results of invoking this algorithm recursively on all
1864 * direct superinterfaces of C, but include only instance methods.</li>
1865 * </ol></li>
1866 * <li> Union from step 1 is partitioned into subsets of methods with same
1867 * signature (name, parameter types) and return type.</li>
1868 * <li> Within each such subset only the most specific methods are selected.
1869 * Let method M be a method from a set of methods with same signature
1870 * and return type. M is most specific if there is no such method
1871 * N != M from the same set, such that N is more specific than M.
1872 * N is more specific than M if:
1873 * <ol type="a">
1874 * <li> N is declared by a class and M is declared by an interface; or</li>
1875 * <li> N and M are both declared by classes or both by interfaces and
1876 * N's declaring type is the same as or a subtype of M's declaring type
1877 * (clearly, if M's and N's declaring types are the same type, then
1878 * M and N are the same method).</li>
1879 * </ol></li>
1880 * <li> The result of this algorithm is the union of all selected methods from
1881 * step 3.</li>
1882 * </ol>
1883 *
1884 * @apiNote There may be more than one method with a particular name
1885 * and parameter types in a class because while the Java language forbids a
1886 * class to declare multiple methods with the same signature but different
1887 * return types, the Java virtual machine does not. This
1888 * increased flexibility in the virtual machine can be used to
1889 * implement various language features. For example, covariant
1890 * returns can be implemented with {@linkplain
1891 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
1892 * method and the overriding method would have the same
1893 * signature but different return types.
1894 *
1895 * @return the array of {@code Method} objects representing the
1896 * public methods of this class
1897 * @throws SecurityException
1898 * If a security manager, <i>s</i>, is present and
1899 * the caller's class loader is not the same as or an
1900 * ancestor of the class loader for the current class and
1901 * invocation of {@link SecurityManager#checkPackageAccess
1902 * s.checkPackageAccess()} denies access to the package
1903 * of this class.
1904 *
1905 * @jls 8.2 Class Members
1906 * @jls 8.4 Method Declarations
1907 * @since 1.1
1908 */
1909 @CallerSensitive
1910 public Method[] getMethods() throws SecurityException {
1911 SecurityManager sm = System.getSecurityManager();
1912 if (sm != null) {
1913 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1914 }
1915 return copyMethods(privateGetPublicMethods());
1916 }
1917
1918
1919 /**
1920 * Returns an array containing {@code Constructor} objects reflecting
1921 * all the public constructors of the class represented by this
1922 * {@code Class} object. An array of length 0 is returned if the
1923 * class has no public constructors, or if the class is an array class, or
1924 * if the class reflects a primitive type or void.
1925 *
1926 * Note that while this method returns an array of {@code
1927 * Constructor<T>} objects (that is an array of constructors from
1928 * this class), the return type of this method is {@code
1929 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
1930 * might be expected. This less informative return type is
1931 * necessary since after being returned from this method, the
1932 * array could be modified to hold {@code Constructor} objects for
1933 * different classes, which would violate the type guarantees of
1934 * {@code Constructor<T>[]}.
1935 *
1936 * @return the array of {@code Constructor} objects representing the
1937 * public constructors of this class
1938 * @throws SecurityException
1939 * If a security manager, <i>s</i>, is present and
1940 * the caller's class loader is not the same as or an
1941 * ancestor of the class loader for the current class and
1942 * invocation of {@link SecurityManager#checkPackageAccess
1943 * s.checkPackageAccess()} denies access to the package
1944 * of this class.
1945 *
1946 * @since 1.1
1947 */
1948 @CallerSensitive
1949 public Constructor<?>[] getConstructors() throws SecurityException {
1950 SecurityManager sm = System.getSecurityManager();
1951 if (sm != null) {
1952 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1953 }
1954 return copyConstructors(privateGetDeclaredConstructors(true));
1955 }
1956
1957
1958 /**
1959 * Returns a {@code Field} object that reflects the specified public member
1960 * field of the class or interface represented by this {@code Class}
1961 * object. The {@code name} parameter is a {@code String} specifying the
1962 * simple name of the desired field.
1963 *
1964 * <p> The field to be reflected is determined by the algorithm that
1965 * follows. Let C be the class or interface represented by this object:
1966 *
1967 * <OL>
1968 * <LI> If C declares a public field with the name specified, that is the
1969 * field to be reflected.</LI>
1970 * <LI> If no field was found in step 1 above, this algorithm is applied
1971 * recursively to each direct superinterface of C. The direct
1972 * superinterfaces are searched in the order they were declared.</LI>
1973 * <LI> If no field was found in steps 1 and 2 above, and C has a
1974 * superclass S, then this algorithm is invoked recursively upon S.
1975 * If C has no superclass, then a {@code NoSuchFieldException}
1976 * is thrown.</LI>
1977 * </OL>
1978 *
1979 * <p> If this {@code Class} object represents an array type, then this
1980 * method does not find the {@code length} field of the array type.
1981 *
1982 * @param name the field name
1983 * @return the {@code Field} object of this class specified by
1984 * {@code name}
1985 * @throws NoSuchFieldException if a field with the specified name is
1986 * not found.
1987 * @throws NullPointerException if {@code name} is {@code null}
1988 * @throws SecurityException
1989 * If a security manager, <i>s</i>, is present and
1990 * the caller's class loader is not the same as or an
1991 * ancestor of the class loader for the current class and
1992 * invocation of {@link SecurityManager#checkPackageAccess
1993 * s.checkPackageAccess()} denies access to the package
1994 * of this class.
1995 *
1996 * @since 1.1
1997 * @jls 8.2 Class Members
1998 * @jls 8.3 Field Declarations
1999 */
2000 @CallerSensitive
2001 public Field getField(String name)
2002 throws NoSuchFieldException, SecurityException {
2003 Objects.requireNonNull(name);
2004 SecurityManager sm = System.getSecurityManager();
2005 if (sm != null) {
2006 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
2007 }
2008 Field field = getField0(name);
2009 if (field == null) {
2010 throw new NoSuchFieldException(name);
2011 }
2012 return getReflectionFactory().copyField(field);
2013 }
2014
2015
2016 /**
2017 * Returns a {@code Method} object that reflects the specified public
2018 * member method of the class or interface represented by this
2019 * {@code Class} object. The {@code name} parameter is a
2020 * {@code String} specifying the simple name of the desired method. The
2021 * {@code parameterTypes} parameter is an array of {@code Class}
2022 * objects that identify the method's formal parameter types, in declared
2023 * order. If {@code parameterTypes} is {@code null}, it is
2024 * treated as if it were an empty array.
2025 *
2026 * <p> If this {@code Class} object represents an array type, then this
2027 * method finds any public method inherited by the array type from
2028 * {@code Object} except method {@code clone()}.
2029 *
2030 * <p> If this {@code Class} object represents an interface then this
2031 * method does not find any implicitly declared method from
2032 * {@code Object}. Therefore, if no methods are explicitly declared in
2033 * this interface or any of its superinterfaces, then this method does not
2034 * find any method.
2035 *
2036 * <p> This method does not find any method with name "{@code <init>}" or
2037 * "{@code <clinit>}".
2038 *
2039 * <p> Generally, the method to be reflected is determined by the 4 step
2040 * algorithm that follows.
2041 * Let C be the class or interface represented by this {@code Class} object:
2042 * <ol>
2043 * <li> A union of methods is composed of:
2044 * <ol type="a">
2045 * <li> C's declared public instance and static methods as returned by
2046 * {@link #getDeclaredMethods()} and filtered to include only public
2047 * methods that match given {@code name} and {@code parameterTypes}</li>
2048 * <li> If C is a class other than {@code Object}, then include the result
2049 * of invoking this algorithm recursively on the superclass of C.</li>
2050 * <li> Include the results of invoking this algorithm recursively on all
2051 * direct superinterfaces of C, but include only instance methods.</li>
2052 * </ol></li>
2053 * <li> This union is partitioned into subsets of methods with same
2054 * return type (the selection of methods from step 1 also guarantees that
2055 * they have the same method name and parameter types).</li>
2056 * <li> Within each such subset only the most specific methods are selected.
2057 * Let method M be a method from a set of methods with same VM
2058 * signature (return type, name, parameter types).
2059 * M is most specific if there is no such method N != M from the same
2060 * set, such that N is more specific than M. N is more specific than M
2061 * if:
2062 * <ol type="a">
2063 * <li> N is declared by a class and M is declared by an interface; or</li>
2064 * <li> N and M are both declared by classes or both by interfaces and
2065 * N's declaring type is the same as or a subtype of M's declaring type
2066 * (clearly, if M's and N's declaring types are the same type, then
2067 * M and N are the same method).</li>
2068 * </ol></li>
2069 * <li> The result of this algorithm is chosen arbitrarily from the methods
2070 * with most specific return type among all selected methods from step 3.
2071 * Let R be a return type of a method M from the set of all selected methods
2072 * from step 3. M is a method with most specific return type if there is
2073 * no such method N != M from the same set, having return type S != R,
2074 * such that S is a subtype of R as determined by
2075 * R.class.{@link #isAssignableFrom}(S.class).
2076 * </ol>
2077 *
2078 * @apiNote There may be more than one method with matching name and
2079 * parameter types in a class because while the Java language forbids a
2080 * class to declare multiple methods with the same signature but different
2081 * return types, the Java virtual machine does not. This
2082 * increased flexibility in the virtual machine can be used to
2083 * implement various language features. For example, covariant
2084 * returns can be implemented with {@linkplain
2085 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2086 * method and the overriding method would have the same
2087 * signature but different return types. This method would return the
2088 * overriding method as it would have a more specific return type.
2089 *
2090 * @param name the name of the method
2091 * @param parameterTypes the list of parameters
2092 * @return the {@code Method} object that matches the specified
2093 * {@code name} and {@code parameterTypes}
2094 * @throws NoSuchMethodException if a matching method is not found
2095 * or if the name is "<init>"or "<clinit>".
2096 * @throws NullPointerException if {@code name} is {@code null}
2097 * @throws SecurityException
2098 * If a security manager, <i>s</i>, is present and
2099 * the caller's class loader is not the same as or an
2100 * ancestor of the class loader for the current class and
2101 * invocation of {@link SecurityManager#checkPackageAccess
2102 * s.checkPackageAccess()} denies access to the package
2103 * of this class.
2104 *
2105 * @jls 8.2 Class Members
2106 * @jls 8.4 Method Declarations
2107 * @since 1.1
2108 */
2109 @CallerSensitive
2110 public Method getMethod(String name, Class<?>... parameterTypes)
2111 throws NoSuchMethodException, SecurityException {
2112 Objects.requireNonNull(name);
2113 SecurityManager sm = System.getSecurityManager();
2114 if (sm != null) {
2115 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
2116 }
2117 Method method = getMethod0(name, parameterTypes);
2118 if (method == null) {
2119 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2120 }
2121 return getReflectionFactory().copyMethod(method);
2122 }
2123
2124 /**
2125 * Returns a {@code Constructor} object that reflects the specified
2126 * public constructor of the class represented by this {@code Class}
2127 * object. The {@code parameterTypes} parameter is an array of
2128 * {@code Class} objects that identify the constructor's formal
2129 * parameter types, in declared order.
2130 *
2131 * If this {@code Class} object represents an inner class
2132 * declared in a non-static context, the formal parameter types
2133 * include the explicit enclosing instance as the first parameter.
2134 *
2135 * <p> The constructor to reflect is the public constructor of the class
2136 * represented by this {@code Class} object whose formal parameter
2137 * types match those specified by {@code parameterTypes}.
2138 *
2139 * @param parameterTypes the parameter array
2140 * @return the {@code Constructor} object of the public constructor that
2141 * matches the specified {@code parameterTypes}
2142 * @throws NoSuchMethodException if a matching method is not found.
2143 * @throws SecurityException
2144 * If a security manager, <i>s</i>, is present and
2145 * the caller's class loader is not the same as or an
2146 * ancestor of the class loader for the current class and
2147 * invocation of {@link SecurityManager#checkPackageAccess
2148 * s.checkPackageAccess()} denies access to the package
2149 * of this class.
2150 *
2151 * @since 1.1
2152 */
2153 @CallerSensitive
2154 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2155 throws NoSuchMethodException, SecurityException
2156 {
2157 SecurityManager sm = System.getSecurityManager();
2158 if (sm != null) {
2159 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
2160 }
2161 return getReflectionFactory().copyConstructor(
2162 getConstructor0(parameterTypes, Member.PUBLIC));
2163 }
2164
2165
2166 /**
2167 * Returns an array of {@code Class} objects reflecting all the
2168 * classes and interfaces declared as members of the class represented by
2169 * this {@code Class} object. This includes public, protected, default
2170 * (package) access, and private classes and interfaces declared by the
2171 * class, but excludes inherited classes and interfaces. This method
2172 * returns an array of length 0 if the class declares no classes or
2173 * interfaces as members, or if this {@code Class} object represents a
2174 * primitive type, an array class, or void.
2175 *
2176 * @return the array of {@code Class} objects representing all the
2177 * declared members of this class
2178 * @throws SecurityException
2179 * If a security manager, <i>s</i>, is present and any of the
2180 * following conditions is met:
2181 *
2182 * <ul>
2183 *
2184 * <li> the caller's class loader is not the same as the
2185 * class loader of this class and invocation of
2186 * {@link SecurityManager#checkPermission
2187 * s.checkPermission} method with
2188 * {@code RuntimePermission("accessDeclaredMembers")}
2189 * denies access to the declared classes within this class
2190 *
2191 * <li> the caller's class loader is not the same as or an
2192 * ancestor of the class loader for the current class and
2193 * invocation of {@link SecurityManager#checkPackageAccess
2194 * s.checkPackageAccess()} denies access to the package
2195 * of this class
2196 *
2197 * </ul>
2198 *
2199 * @since 1.1
2200 */
2201 @CallerSensitive
2202 public Class<?>[] getDeclaredClasses() throws SecurityException {
2203 SecurityManager sm = System.getSecurityManager();
2204 if (sm != null) {
2205 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), false);
2206 }
2207 return getDeclaredClasses0();
2208 }
2209
2210
2211 /**
2212 * Returns an array of {@code Field} objects reflecting all the fields
2213 * declared by the class or interface represented by this
2214 * {@code Class} object. This includes public, protected, default
2215 * (package) access, and private fields, but excludes inherited fields.
2216 *
2217 * <p> If this {@code Class} object represents a class or interface with no
2218 * declared fields, then this method returns an array of length 0.
2219 *
2220 * <p> If this {@code Class} object represents an array type, a primitive
2221 * type, or void, then this method returns an array of length 0.
2222 *
2223 * <p> The elements in the returned array are not sorted and are not in any
2224 * particular order.
2225 *
2226 * @return the array of {@code Field} objects representing all the
2227 * declared fields of this class
2228 * @throws SecurityException
2229 * If a security manager, <i>s</i>, is present and any of the
2230 * following conditions is met:
2231 *
2232 * <ul>
2233 *
2234 * <li> the caller's class loader is not the same as the
2235 * class loader of this class and invocation of
2236 * {@link SecurityManager#checkPermission
2237 * s.checkPermission} method with
2238 * {@code RuntimePermission("accessDeclaredMembers")}
2239 * denies access to the declared fields within this class
2240 *
2241 * <li> the caller's class loader is not the same as or an
2242 * ancestor of the class loader for the current class and
2243 * invocation of {@link SecurityManager#checkPackageAccess
2244 * s.checkPackageAccess()} denies access to the package
2245 * of this class
2246 *
2247 * </ul>
2248 *
2249 * @since 1.1
2250 * @jls 8.2 Class Members
2251 * @jls 8.3 Field Declarations
2252 */
2253 @CallerSensitive
2254 public Field[] getDeclaredFields() throws SecurityException {
2255 SecurityManager sm = System.getSecurityManager();
2256 if (sm != null) {
2257 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2258 }
2259 return copyFields(privateGetDeclaredFields(false));
2260 }
2261
2262
2263 /**
2264 * Returns an array containing {@code Method} objects reflecting all the
2265 * declared methods of the class or interface represented by this {@code
2266 * Class} object, including public, protected, default (package)
2267 * access, and private methods, but excluding inherited methods.
2268 *
2269 * <p> If this {@code Class} object represents a type that has multiple
2270 * declared methods with the same name and parameter types, but different
2271 * return types, then the returned array has a {@code Method} object for
2272 * each such method.
2273 *
2274 * <p> If this {@code Class} object represents a type that has a class
2275 * initialization method {@code <clinit>}, then the returned array does
2276 * <em>not</em> have a corresponding {@code Method} object.
2277 *
2278 * <p> If this {@code Class} object represents a class or interface with no
2279 * declared methods, then the returned array has length 0.
2280 *
2281 * <p> If this {@code Class} object represents an array type, a primitive
2282 * type, or void, then the returned array has length 0.
2283 *
2284 * <p> The elements in the returned array are not sorted and are not in any
2285 * particular order.
2286 *
2287 * @return the array of {@code Method} objects representing all the
2288 * declared methods of this class
2289 * @throws SecurityException
2290 * If a security manager, <i>s</i>, is present and any of the
2291 * following conditions is met:
2292 *
2293 * <ul>
2294 *
2295 * <li> the caller's class loader is not the same as the
2296 * class loader of this class and invocation of
2297 * {@link SecurityManager#checkPermission
2298 * s.checkPermission} method with
2299 * {@code RuntimePermission("accessDeclaredMembers")}
2300 * denies access to the declared methods within this class
2301 *
2302 * <li> the caller's class loader is not the same as or an
2303 * ancestor of the class loader for the current class and
2304 * invocation of {@link SecurityManager#checkPackageAccess
2305 * s.checkPackageAccess()} denies access to the package
2306 * of this class
2307 *
2308 * </ul>
2309 *
2310 * @jls 8.2 Class Members
2311 * @jls 8.4 Method Declarations
2312 * @since 1.1
2313 */
2314 @CallerSensitive
2315 public Method[] getDeclaredMethods() throws SecurityException {
2316 SecurityManager sm = System.getSecurityManager();
2317 if (sm != null) {
2318 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2319 }
2320 return copyMethods(privateGetDeclaredMethods(false));
2321 }
2322
2323
2324 /**
2325 * Returns an array of {@code Constructor} objects reflecting all the
2326 * constructors declared by the class represented by this
2327 * {@code Class} object. These are public, protected, default
2328 * (package) access, and private constructors. The elements in the array
2329 * returned are not sorted and are not in any particular order. If the
2330 * class has a default constructor, it is included in the returned array.
2331 * This method returns an array of length 0 if this {@code Class}
2332 * object represents an interface, a primitive type, an array class, or
2333 * void.
2334 *
2335 * <p> See <em>The Java Language Specification</em>, section 8.2.
2336 *
2337 * @return the array of {@code Constructor} objects representing all the
2338 * declared constructors of this class
2339 * @throws SecurityException
2340 * If a security manager, <i>s</i>, is present and any of the
2341 * following conditions is met:
2342 *
2343 * <ul>
2344 *
2345 * <li> the caller's class loader is not the same as the
2346 * class loader of this class and invocation of
2347 * {@link SecurityManager#checkPermission
2348 * s.checkPermission} method with
2349 * {@code RuntimePermission("accessDeclaredMembers")}
2350 * denies access to the declared constructors within this class
2351 *
2352 * <li> the caller's class loader is not the same as or an
2353 * ancestor of the class loader for the current class and
2354 * invocation of {@link SecurityManager#checkPackageAccess
2355 * s.checkPackageAccess()} denies access to the package
2356 * of this class
2357 *
2358 * </ul>
2359 *
2360 * @since 1.1
2361 */
2362 @CallerSensitive
2363 public Constructor<?>[] getDeclaredConstructors() throws SecurityException {
2364 SecurityManager sm = System.getSecurityManager();
2365 if (sm != null) {
2366 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2367 }
2368 return copyConstructors(privateGetDeclaredConstructors(false));
2369 }
2370
2371
2372 /**
2373 * Returns a {@code Field} object that reflects the specified declared
2374 * field of the class or interface represented by this {@code Class}
2375 * object. The {@code name} parameter is a {@code String} that specifies
2376 * the simple name of the desired field.
2377 *
2378 * <p> If this {@code Class} object represents an array type, then this
2379 * method does not find the {@code length} field of the array type.
2380 *
2381 * @param name the name of the field
2382 * @return the {@code Field} object for the specified field in this
2383 * class
2384 * @throws NoSuchFieldException if a field with the specified name is
2385 * not found.
2386 * @throws NullPointerException if {@code name} is {@code null}
2387 * @throws SecurityException
2388 * If a security manager, <i>s</i>, is present and any of the
2389 * following conditions is met:
2390 *
2391 * <ul>
2392 *
2393 * <li> the caller's class loader is not the same as the
2394 * class loader of this class and invocation of
2395 * {@link SecurityManager#checkPermission
2396 * s.checkPermission} method with
2397 * {@code RuntimePermission("accessDeclaredMembers")}
2398 * denies access to the declared field
2399 *
2400 * <li> the caller's class loader is not the same as or an
2401 * ancestor of the class loader for the current class and
2402 * invocation of {@link SecurityManager#checkPackageAccess
2403 * s.checkPackageAccess()} denies access to the package
2404 * of this class
2405 *
2406 * </ul>
2407 *
2408 * @since 1.1
2409 * @jls 8.2 Class Members
2410 * @jls 8.3 Field Declarations
2411 */
2412 @CallerSensitive
2413 public Field getDeclaredField(String name)
2414 throws NoSuchFieldException, SecurityException {
2415 Objects.requireNonNull(name);
2416 SecurityManager sm = System.getSecurityManager();
2417 if (sm != null) {
2418 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2419 }
2420 Field field = searchFields(privateGetDeclaredFields(false), name);
2421 if (field == null) {
2422 throw new NoSuchFieldException(name);
2423 }
2424 return getReflectionFactory().copyField(field);
2425 }
2426
2427
2428 /**
2429 * Returns a {@code Method} object that reflects the specified
2430 * declared method of the class or interface represented by this
2431 * {@code Class} object. The {@code name} parameter is a
2432 * {@code String} that specifies the simple name of the desired
2433 * method, and the {@code parameterTypes} parameter is an array of
2434 * {@code Class} objects that identify the method's formal parameter
2435 * types, in declared order. If more than one method with the same
2436 * parameter types is declared in a class, and one of these methods has a
2437 * return type that is more specific than any of the others, that method is
2438 * returned; otherwise one of the methods is chosen arbitrarily. If the
2439 * name is "<init>"or "<clinit>" a {@code NoSuchMethodException}
2440 * is raised.
2441 *
2442 * <p> If this {@code Class} object represents an array type, then this
2443 * method does not find the {@code clone()} method.
2444 *
2445 * @param name the name of the method
2446 * @param parameterTypes the parameter array
2447 * @return the {@code Method} object for the method of this class
2448 * matching the specified name and parameters
2449 * @throws NoSuchMethodException if a matching method is not found.
2450 * @throws NullPointerException if {@code name} is {@code null}
2451 * @throws SecurityException
2452 * If a security manager, <i>s</i>, is present and any of the
2453 * following conditions is met:
2454 *
2455 * <ul>
2456 *
2457 * <li> the caller's class loader is not the same as the
2458 * class loader of this class and invocation of
2459 * {@link SecurityManager#checkPermission
2460 * s.checkPermission} method with
2461 * {@code RuntimePermission("accessDeclaredMembers")}
2462 * denies access to the declared method
2463 *
2464 * <li> the caller's class loader is not the same as or an
2465 * ancestor of the class loader for the current class and
2466 * invocation of {@link SecurityManager#checkPackageAccess
2467 * s.checkPackageAccess()} denies access to the package
2468 * of this class
2469 *
2470 * </ul>
2471 *
2472 * @jls 8.2 Class Members
2473 * @jls 8.4 Method Declarations
2474 * @since 1.1
2475 */
2476 @CallerSensitive
2477 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2478 throws NoSuchMethodException, SecurityException {
2479 Objects.requireNonNull(name);
2480 SecurityManager sm = System.getSecurityManager();
2481 if (sm != null) {
2482 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2483 }
2484 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2485 if (method == null) {
2486 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2487 }
2488 return getReflectionFactory().copyMethod(method);
2489 }
2490
2491 /**
2492 * Returns the list of {@code Method} objects for the declared public
2493 * methods of this class or interface that have the specified method name
2494 * and parameter types.
2495 *
2496 * @param name the name of the method
2497 * @param parameterTypes the parameter array
2498 * @return the list of {@code Method} objects for the public methods of
2499 * this class matching the specified name and parameters
2500 */
2501 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2502 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2503 ReflectionFactory factory = getReflectionFactory();
2504 List<Method> result = new ArrayList<>();
2505 for (Method method : methods) {
2506 if (method.getName().equals(name)
2507 && Arrays.equals(
2508 factory.getExecutableSharedParameterTypes(method),
2509 parameterTypes)) {
2510 result.add(factory.copyMethod(method));
2511 }
2512 }
2513 return result;
2514 }
2515
2516 /**
2517 * Returns a {@code Constructor} object that reflects the specified
2518 * constructor of the class or interface represented by this
2519 * {@code Class} object. The {@code parameterTypes} parameter is
2520 * an array of {@code Class} objects that identify the constructor's
2521 * formal parameter types, in declared order.
2522 *
2523 * If this {@code Class} object represents an inner class
2524 * declared in a non-static context, the formal parameter types
2525 * include the explicit enclosing instance as the first parameter.
2526 *
2527 * @param parameterTypes the parameter array
2528 * @return The {@code Constructor} object for the constructor with the
2529 * specified parameter list
2530 * @throws NoSuchMethodException if a matching method is not found.
2531 * @throws SecurityException
2532 * If a security manager, <i>s</i>, is present and any of the
2533 * following conditions is met:
2534 *
2535 * <ul>
2536 *
2537 * <li> the caller's class loader is not the same as the
2538 * class loader of this class and invocation of
2539 * {@link SecurityManager#checkPermission
2540 * s.checkPermission} method with
2541 * {@code RuntimePermission("accessDeclaredMembers")}
2542 * denies access to the declared constructor
2543 *
2544 * <li> the caller's class loader is not the same as or an
2545 * ancestor of the class loader for the current class and
2546 * invocation of {@link SecurityManager#checkPackageAccess
2547 * s.checkPackageAccess()} denies access to the package
2548 * of this class
2549 *
2550 * </ul>
2551 *
2552 * @since 1.1
2553 */
2554 @CallerSensitive
2555 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2556 throws NoSuchMethodException, SecurityException
2557 {
2558 SecurityManager sm = System.getSecurityManager();
2559 if (sm != null) {
2560 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2561 }
2562
2563 return getReflectionFactory().copyConstructor(
2564 getConstructor0(parameterTypes, Member.DECLARED));
2565 }
2566
2567 /**
2568 * Finds a resource with a given name.
2569 *
2570 * <p> If this class is in a named {@link Module Module} then this method
2571 * will attempt to find the resource in the module. This is done by
2572 * delegating to the module's class loader {@link
2573 * ClassLoader#findResource(String,String) findResource(String,String)}
2574 * method, invoking it with the module name and the absolute name of the
2575 * resource. Resources in named modules are subject to the rules for
2576 * encapsulation specified in the {@code Module} {@link
2577 * Module#getResourceAsStream getResourceAsStream} method and so this
2578 * method returns {@code null} when the resource is a
2579 * non-"{@code .class}" resource in a package that is not open to the
2580 * caller's module.
2581 *
2582 * <p> Otherwise, if this class is not in a named module then the rules for
2583 * searching resources associated with a given class are implemented by the
2584 * defining {@linkplain ClassLoader class loader} of the class. This method
2585 * delegates to this object's class loader. If this object was loaded by
2586 * the bootstrap class loader, the method delegates to {@link
2587 * ClassLoader#getSystemResourceAsStream}.
2588 *
2589 * <p> Before delegation, an absolute resource name is constructed from the
2590 * given resource name using this algorithm:
2591 *
2592 * <ul>
2593 *
2594 * <li> If the {@code name} begins with a {@code '/'}
2595 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2596 * portion of the {@code name} following the {@code '/'}.
2597 *
2598 * <li> Otherwise, the absolute name is of the following form:
2599 *
2600 * <blockquote>
2601 * {@code modified_package_name/name}
2602 * </blockquote>
2603 *
2604 * <p> Where the {@code modified_package_name} is the package name of this
2605 * object with {@code '/'} substituted for {@code '.'}
2606 * (<code>'\u002e'</code>).
2607 *
2608 * </ul>
2609 *
2610 * @param name name of the desired resource
2611 * @return A {@link java.io.InputStream} object; {@code null} if no
2612 * resource with this name is found, the resource is in a package
2613 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2614 * least the caller module, or access to the resource is denied
2615 * by the security manager.
2616 * @throws NullPointerException If {@code name} is {@code null}
2617 *
2618 * @see Module#getResourceAsStream(String)
2619 * @since 1.1
2620 * @revised 9
2621 * @spec JPMS
2622 */
2623 @CallerSensitive
2624 public InputStream getResourceAsStream(String name) {
2625 name = resolveName(name);
2626
2627 Module thisModule = getModule();
2628 if (thisModule.isNamed()) {
2629 // check if resource can be located by caller
2630 if (Resources.canEncapsulate(name)
2631 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2632 return null;
2633 }
2634
2635 // resource not encapsulated or in package open to caller
2636 String mn = thisModule.getName();
2637 ClassLoader cl = getClassLoader0();
2638 try {
2639
2640 // special-case built-in class loaders to avoid the
2641 // need for a URL connection
2642 if (cl == null) {
2643 return BootLoader.findResourceAsStream(mn, name);
2644 } else if (cl instanceof BuiltinClassLoader) {
2645 return ((BuiltinClassLoader) cl).findResourceAsStream(mn, name);
2646 } else {
2647 URL url = cl.findResource(mn, name);
2648 return (url != null) ? url.openStream() : null;
2649 }
2650
2651 } catch (IOException | SecurityException e) {
2652 return null;
2653 }
2654 }
2655
2656 // unnamed module
2657 ClassLoader cl = getClassLoader0();
2658 if (cl == null) {
2659 return ClassLoader.getSystemResourceAsStream(name);
2660 } else {
2661 return cl.getResourceAsStream(name);
2662 }
2663 }
2664
2665 /**
2666 * Finds a resource with a given name.
2667 *
2668 * <p> If this class is in a named {@link Module Module} then this method
2669 * will attempt to find the resource in the module. This is done by
2670 * delegating to the module's class loader {@link
2671 * ClassLoader#findResource(String,String) findResource(String,String)}
2672 * method, invoking it with the module name and the absolute name of the
2673 * resource. Resources in named modules are subject to the rules for
2674 * encapsulation specified in the {@code Module} {@link
2675 * Module#getResourceAsStream getResourceAsStream} method and so this
2676 * method returns {@code null} when the resource is a
2677 * non-"{@code .class}" resource in a package that is not open to the
2678 * caller's module.
2679 *
2680 * <p> Otherwise, if this class is not in a named module then the rules for
2681 * searching resources associated with a given class are implemented by the
2682 * defining {@linkplain ClassLoader class loader} of the class. This method
2683 * delegates to this object's class loader. If this object was loaded by
2684 * the bootstrap class loader, the method delegates to {@link
2685 * ClassLoader#getSystemResource}.
2686 *
2687 * <p> Before delegation, an absolute resource name is constructed from the
2688 * given resource name using this algorithm:
2689 *
2690 * <ul>
2691 *
2692 * <li> If the {@code name} begins with a {@code '/'}
2693 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2694 * portion of the {@code name} following the {@code '/'}.
2695 *
2696 * <li> Otherwise, the absolute name is of the following form:
2697 *
2698 * <blockquote>
2699 * {@code modified_package_name/name}
2700 * </blockquote>
2701 *
2702 * <p> Where the {@code modified_package_name} is the package name of this
2703 * object with {@code '/'} substituted for {@code '.'}
2704 * (<code>'\u002e'</code>).
2705 *
2706 * </ul>
2707 *
2708 * @param name name of the desired resource
2709 * @return A {@link java.net.URL} object; {@code null} if no resource with
2710 * this name is found, the resource cannot be located by a URL, the
2711 * resource is in a package that is not
2712 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2713 * module, or access to the resource is denied by the security
2714 * manager.
2715 * @throws NullPointerException If {@code name} is {@code null}
2716 * @since 1.1
2717 * @revised 9
2718 * @spec JPMS
2719 */
2720 @CallerSensitive
2721 public URL getResource(String name) {
2722 name = resolveName(name);
2723
2724 Module thisModule = getModule();
2725 if (thisModule.isNamed()) {
2726 // check if resource can be located by caller
2727 if (Resources.canEncapsulate(name)
2728 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2729 return null;
2730 }
2731
2732 // resource not encapsulated or in package open to caller
2733 String mn = thisModule.getName();
2734 ClassLoader cl = getClassLoader0();
2735 try {
2736 if (cl == null) {
2737 return BootLoader.findResource(mn, name);
2738 } else {
2739 return cl.findResource(mn, name);
2740 }
2741 } catch (IOException ioe) {
2742 return null;
2743 }
2744 }
2745
2746 // unnamed module
2747 ClassLoader cl = getClassLoader0();
2748 if (cl == null) {
2749 return ClassLoader.getSystemResource(name);
2750 } else {
2751 return cl.getResource(name);
2752 }
2753 }
2754
2755 /**
2756 * Returns true if a resource with the given name can be located by the
2757 * given caller. All resources in a module can be located by code in
2758 * the module. For other callers, then the package needs to be open to
2759 * the caller.
2760 */
2761 private boolean isOpenToCaller(String name, Class<?> caller) {
2762 // assert getModule().isNamed();
2763 Module thisModule = getModule();
2764 Module callerModule = (caller != null) ? caller.getModule() : null;
2765 if (callerModule != thisModule) {
2766 String pn = Resources.toPackageName(name);
2767 if (thisModule.getDescriptor().packages().contains(pn)) {
2768 if (callerModule == null && !thisModule.isOpen(pn)) {
2769 // no caller, package not open
2770 return false;
2771 }
2772 if (!thisModule.isOpen(pn, callerModule)) {
2773 // package not open to caller
2774 return false;
2775 }
2776 }
2777 }
2778 return true;
2779 }
2780
2781
2782 /** protection domain returned when the internal domain is null */
2783 private static java.security.ProtectionDomain allPermDomain;
2784
2785 /**
2786 * Returns the {@code ProtectionDomain} of this class. If there is a
2787 * security manager installed, this method first calls the security
2788 * manager's {@code checkPermission} method with a
2789 * {@code RuntimePermission("getProtectionDomain")} permission to
2790 * ensure it's ok to get the
2791 * {@code ProtectionDomain}.
2792 *
2793 * @return the ProtectionDomain of this class
2794 *
2795 * @throws SecurityException
2796 * if a security manager exists and its
2797 * {@code checkPermission} method doesn't allow
2798 * getting the ProtectionDomain.
2799 *
2800 * @see java.security.ProtectionDomain
2801 * @see SecurityManager#checkPermission
2802 * @see java.lang.RuntimePermission
2803 * @since 1.2
2804 */
2805 public java.security.ProtectionDomain getProtectionDomain() {
2806 SecurityManager sm = System.getSecurityManager();
2807 if (sm != null) {
2808 sm.checkPermission(SecurityConstants.GET_PD_PERMISSION);
2809 }
2810 java.security.ProtectionDomain pd = getProtectionDomain0();
2811 if (pd == null) {
2812 if (allPermDomain == null) {
2813 java.security.Permissions perms =
2814 new java.security.Permissions();
2815 perms.add(SecurityConstants.ALL_PERMISSION);
2816 allPermDomain =
2817 new java.security.ProtectionDomain(null, perms);
2818 }
2819 pd = allPermDomain;
2820 }
2821 return pd;
2822 }
2823
2824
2825 /**
2826 * Returns the ProtectionDomain of this class.
2827 */
2828 private native java.security.ProtectionDomain getProtectionDomain0();
2829
2830 /*
2831 * Return the Virtual Machine's Class object for the named
2832 * primitive type.
2833 */
2834 static native Class<?> getPrimitiveClass(String name);
2835
2836 /*
2837 * Check if client is allowed to access members. If access is denied,
2838 * throw a SecurityException.
2839 *
2840 * This method also enforces package access.
2841 *
2842 * <p> Default policy: allow all clients access with normal Java access
2843 * control.
2844 *
2845 * <p> NOTE: should only be called if a SecurityManager is installed
2846 */
2847 private void checkMemberAccess(SecurityManager sm, int which,
2848 Class<?> caller, boolean checkProxyInterfaces) {
2849 /* Default policy allows access to all {@link Member#PUBLIC} members,
2850 * as well as access to classes that have the same class loader as the caller.
2851 * In all other cases, it requires RuntimePermission("accessDeclaredMembers")
2852 * permission.
2853 */
2854 final ClassLoader ccl = ClassLoader.getClassLoader(caller);
2855 if (which != Member.PUBLIC) {
2856 final ClassLoader cl = getClassLoader0();
2857 if (ccl != cl) {
2858 sm.checkPermission(SecurityConstants.CHECK_MEMBER_ACCESS_PERMISSION);
2859 }
2860 }
2861 this.checkPackageAccess(sm, ccl, checkProxyInterfaces);
2862 }
2863
2864 /*
2865 * Checks if a client loaded in ClassLoader ccl is allowed to access this
2866 * class under the current package access policy. If access is denied,
2867 * throw a SecurityException.
2868 *
2869 * NOTE: this method should only be called if a SecurityManager is active
2870 */
2871 private void checkPackageAccess(SecurityManager sm, final ClassLoader ccl,
2872 boolean checkProxyInterfaces) {
2873 final ClassLoader cl = getClassLoader0();
2874
2875 if (ReflectUtil.needsPackageAccessCheck(ccl, cl)) {
2876 String pkg = this.getPackageName();
2877 if (pkg != null && !pkg.isEmpty()) {
2878 // skip the package access check on a proxy class in default proxy package
2879 if (!Proxy.isProxyClass(this) || ReflectUtil.isNonPublicProxyClass(this)) {
2880 sm.checkPackageAccess(pkg);
2881 }
2882 }
2883 }
2884 // check package access on the proxy interfaces
2885 if (checkProxyInterfaces && Proxy.isProxyClass(this)) {
2886 ReflectUtil.checkProxyPackageAccess(ccl, this.getInterfaces());
2887 }
2888 }
2889
2890 /**
2891 * Add a package name prefix if the name is not absolute Remove leading "/"
2892 * if name is absolute
2893 */
2894 private String resolveName(String name) {
2895 if (!name.startsWith("/")) {
2896 Class<?> c = this;
2897 while (c.isArray()) {
2898 c = c.getComponentType();
2899 }
2900 String baseName = c.getPackageName();
2901 if (baseName != null && !baseName.isEmpty()) {
2902 name = baseName.replace('.', '/') + "/" + name;
2903 }
2904 } else {
2905 name = name.substring(1);
2906 }
2907 return name;
2908 }
2909
2910 /**
2911 * Atomic operations support.
2912 */
2913 private static class Atomic {
2914 // initialize Unsafe machinery here, since we need to call Class.class instance method
2915 // and have to avoid calling it in the static initializer of the Class class...
2916 private static final Unsafe unsafe = Unsafe.getUnsafe();
2917 // offset of Class.reflectionData instance field
2918 private static final long reflectionDataOffset
2919 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2920 // offset of Class.annotationType instance field
2921 private static final long annotationTypeOffset
2922 = unsafe.objectFieldOffset(Class.class, "annotationType");
2923 // offset of Class.annotationData instance field
2924 private static final long annotationDataOffset
2925 = unsafe.objectFieldOffset(Class.class, "annotationData");
2926
2927 static <T> boolean casReflectionData(Class<?> clazz,
2928 SoftReference<ReflectionData<T>> oldData,
2929 SoftReference<ReflectionData<T>> newData) {
2930 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2931 }
2932
2933 static <T> boolean casAnnotationType(Class<?> clazz,
2934 AnnotationType oldType,
2935 AnnotationType newType) {
2936 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2937 }
2938
2939 static <T> boolean casAnnotationData(Class<?> clazz,
2940 AnnotationData oldData,
2941 AnnotationData newData) {
2942 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2943 }
2944 }
2945
2946 /**
2947 * Reflection support.
2948 */
2949
2950 // Reflection data caches various derived names and reflective members. Cached
2951 // values may be invalidated when JVM TI RedefineClasses() is called
2952 private static class ReflectionData<T> {
2953 volatile Field[] declaredFields;
2954 volatile Field[] publicFields;
2955 volatile Method[] declaredMethods;
2956 volatile Method[] publicMethods;
2957 volatile Constructor<T>[] declaredConstructors;
2958 volatile Constructor<T>[] publicConstructors;
2959 // Intermediate results for getFields and getMethods
2960 volatile Field[] declaredPublicFields;
2961 volatile Method[] declaredPublicMethods;
2962 volatile Class<?>[] interfaces;
2963
2964 // Cached names
2965 String simpleName;
2966 String canonicalName;
2967 static final String NULL_SENTINEL = new String();
2968
2969 // Value of classRedefinedCount when we created this ReflectionData instance
2970 final int redefinedCount;
2971
2972 ReflectionData(int redefinedCount) {
2973 this.redefinedCount = redefinedCount;
2974 }
2975 }
2976
2977 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2978
2979 // Incremented by the VM on each call to JVM TI RedefineClasses()
2980 // that redefines this class or a superclass.
2981 private transient volatile int classRedefinedCount;
2982
2983 // Lazily create and cache ReflectionData
2984 private ReflectionData<T> reflectionData() {
2985 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2986 int classRedefinedCount = this.classRedefinedCount;
2987 ReflectionData<T> rd;
2988 if (reflectionData != null &&
2989 (rd = reflectionData.get()) != null &&
2990 rd.redefinedCount == classRedefinedCount) {
2991 return rd;
2992 }
2993 // else no SoftReference or cleared SoftReference or stale ReflectionData
2994 // -> create and replace new instance
2995 return newReflectionData(reflectionData, classRedefinedCount);
2996 }
2997
2998 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
2999 int classRedefinedCount) {
3000 while (true) {
3001 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
3002 // try to CAS it...
3003 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
3004 return rd;
3005 }
3006 // else retry
3007 oldReflectionData = this.reflectionData;
3008 classRedefinedCount = this.classRedefinedCount;
3009 if (oldReflectionData != null &&
3010 (rd = oldReflectionData.get()) != null &&
3011 rd.redefinedCount == classRedefinedCount) {
3012 return rd;
3013 }
3014 }
3015 }
3016
3017 // Generic signature handling
3018 private native String getGenericSignature0();
3019
3020 // Generic info repository; lazily initialized
3021 private transient volatile ClassRepository genericInfo;
3022
3023 // accessor for factory
3024 private GenericsFactory getFactory() {
3025 // create scope and factory
3026 return CoreReflectionFactory.make(this, ClassScope.make(this));
3027 }
3028
3029 // accessor for generic info repository;
3030 // generic info is lazily initialized
3031 private ClassRepository getGenericInfo() {
3032 ClassRepository genericInfo = this.genericInfo;
3033 if (genericInfo == null) {
3034 String signature = getGenericSignature0();
3035 if (signature == null) {
3036 genericInfo = ClassRepository.NONE;
3037 } else {
3038 genericInfo = ClassRepository.make(signature, getFactory());
3039 }
3040 this.genericInfo = genericInfo;
3041 }
3042 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
3043 }
3044
3045 // Annotations handling
3046 native byte[] getRawAnnotations();
3047 // Since 1.8
3048 native byte[] getRawTypeAnnotations();
3049 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
3050 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
3051 }
3052
3053 native ConstantPool getConstantPool();
3054
3055 //
3056 //
3057 // java.lang.reflect.Field handling
3058 //
3059 //
3060
3061 // Returns an array of "root" fields. These Field objects must NOT
3062 // be propagated to the outside world, but must instead be copied
3063 // via ReflectionFactory.copyField.
3064 private Field[] privateGetDeclaredFields(boolean publicOnly) {
3065 Field[] res;
3066 ReflectionData<T> rd = reflectionData();
3067 if (rd != null) {
3068 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
3069 if (res != null) return res;
3070 }
3071 // No cached value available; request value from VM
3072 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
3073 if (rd != null) {
3074 if (publicOnly) {
3075 rd.declaredPublicFields = res;
3076 } else {
3077 rd.declaredFields = res;
3078 }
3079 }
3080 return res;
3081 }
3082
3083 // Returns an array of "root" fields. These Field objects must NOT
3084 // be propagated to the outside world, but must instead be copied
3085 // via ReflectionFactory.copyField.
3086 private Field[] privateGetPublicFields() {
3087 Field[] res;
3088 ReflectionData<T> rd = reflectionData();
3089 if (rd != null) {
3090 res = rd.publicFields;
3091 if (res != null) return res;
3092 }
3093
3094 // Use a linked hash set to ensure order is preserved and
3095 // fields from common super interfaces are not duplicated
3096 LinkedHashSet<Field> fields = new LinkedHashSet<>();
3097
3098 // Local fields
3099 addAll(fields, privateGetDeclaredFields(true));
3100
3101 // Direct superinterfaces, recursively
3102 for (Class<?> si : getInterfaces()) {
3103 addAll(fields, si.privateGetPublicFields());
3104 }
3105
3106 // Direct superclass, recursively
3107 Class<?> sc = getSuperclass();
3108 if (sc != null) {
3109 addAll(fields, sc.privateGetPublicFields());
3110 }
3111
3112 res = fields.toArray(new Field[0]);
3113 if (rd != null) {
3114 rd.publicFields = res;
3115 }
3116 return res;
3117 }
3118
3119 private static void addAll(Collection<Field> c, Field[] o) {
3120 for (Field f : o) {
3121 c.add(f);
3122 }
3123 }
3124
3125
3126 //
3127 //
3128 // java.lang.reflect.Constructor handling
3129 //
3130 //
3131
3132 // Returns an array of "root" constructors. These Constructor
3133 // objects must NOT be propagated to the outside world, but must
3134 // instead be copied via ReflectionFactory.copyConstructor.
3135 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3136 Constructor<T>[] res;
3137 ReflectionData<T> rd = reflectionData();
3138 if (rd != null) {
3139 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3140 if (res != null) return res;
3141 }
3142 // No cached value available; request value from VM
3143 if (isInterface()) {
3144 @SuppressWarnings("unchecked")
3145 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3146 res = temporaryRes;
3147 } else {
3148 res = getDeclaredConstructors0(publicOnly);
3149 }
3150 if (rd != null) {
3151 if (publicOnly) {
3152 rd.publicConstructors = res;
3153 } else {
3154 rd.declaredConstructors = res;
3155 }
3156 }
3157 return res;
3158 }
3159
3160 //
3161 //
3162 // java.lang.reflect.Method handling
3163 //
3164 //
3165
3166 // Returns an array of "root" methods. These Method objects must NOT
3167 // be propagated to the outside world, but must instead be copied
3168 // via ReflectionFactory.copyMethod.
3169 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3170 Method[] res;
3171 ReflectionData<T> rd = reflectionData();
3172 if (rd != null) {
3173 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3174 if (res != null) return res;
3175 }
3176 // No cached value available; request value from VM
3177 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3178 if (rd != null) {
3179 if (publicOnly) {
3180 rd.declaredPublicMethods = res;
3181 } else {
3182 rd.declaredMethods = res;
3183 }
3184 }
3185 return res;
3186 }
3187
3188 // Returns an array of "root" methods. These Method objects must NOT
3189 // be propagated to the outside world, but must instead be copied
3190 // via ReflectionFactory.copyMethod.
3191 private Method[] privateGetPublicMethods() {
3192 Method[] res;
3193 ReflectionData<T> rd = reflectionData();
3194 if (rd != null) {
3195 res = rd.publicMethods;
3196 if (res != null) return res;
3197 }
3198
3199 // No cached value available; compute value recursively.
3200 // Start by fetching public declared methods...
3201 PublicMethods pms = new PublicMethods();
3202 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3203 pms.merge(m);
3204 }
3205 // ...then recur over superclass methods...
3206 Class<?> sc = getSuperclass();
3207 if (sc != null) {
3208 for (Method m : sc.privateGetPublicMethods()) {
3209 pms.merge(m);
3210 }
3211 }
3212 // ...and finally over direct superinterfaces.
3213 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3214 for (Method m : intf.privateGetPublicMethods()) {
3215 // static interface methods are not inherited
3216 if (!Modifier.isStatic(m.getModifiers())) {
3217 pms.merge(m);
3218 }
3219 }
3220 }
3221
3222 res = pms.toArray();
3223 if (rd != null) {
3224 rd.publicMethods = res;
3225 }
3226 return res;
3227 }
3228
3229
3230 //
3231 // Helpers for fetchers of one field, method, or constructor
3232 //
3233
3234 // This method does not copy the returned Field object!
3235 private static Field searchFields(Field[] fields, String name) {
3236 for (Field field : fields) {
3237 if (field.getName().equals(name)) {
3238 return field;
3239 }
3240 }
3241 return null;
3242 }
3243
3244 // Returns a "root" Field object. This Field object must NOT
3245 // be propagated to the outside world, but must instead be copied
3246 // via ReflectionFactory.copyField.
3247 private Field getField0(String name) {
3248 // Note: the intent is that the search algorithm this routine
3249 // uses be equivalent to the ordering imposed by
3250 // privateGetPublicFields(). It fetches only the declared
3251 // public fields for each class, however, to reduce the number
3252 // of Field objects which have to be created for the common
3253 // case where the field being requested is declared in the
3254 // class which is being queried.
3255 Field res;
3256 // Search declared public fields
3257 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3258 return res;
3259 }
3260 // Direct superinterfaces, recursively
3261 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3262 for (Class<?> c : interfaces) {
3263 if ((res = c.getField0(name)) != null) {
3264 return res;
3265 }
3266 }
3267 // Direct superclass, recursively
3268 if (!isInterface()) {
3269 Class<?> c = getSuperclass();
3270 if (c != null) {
3271 if ((res = c.getField0(name)) != null) {
3272 return res;
3273 }
3274 }
3275 }
3276 return null;
3277 }
3278
3279 // This method does not copy the returned Method object!
3280 private static Method searchMethods(Method[] methods,
3281 String name,
3282 Class<?>[] parameterTypes)
3283 {
3284 ReflectionFactory fact = getReflectionFactory();
3285 Method res = null;
3286 for (Method m : methods) {
3287 if (m.getName().equals(name)
3288 && arrayContentsEq(parameterTypes,
3289 fact.getExecutableSharedParameterTypes(m))
3290 && (res == null
3291 || (res.getReturnType() != m.getReturnType()
3292 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3293 res = m;
3294 }
3295 return res;
3296 }
3297
3298 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3299
3300 // Returns a "root" Method object. This Method object must NOT
3301 // be propagated to the outside world, but must instead be copied
3302 // via ReflectionFactory.copyMethod.
3303 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3304 PublicMethods.MethodList res = getMethodsRecursive(
3305 name,
3306 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3307 /* includeStatic */ true);
3308 return res == null ? null : res.getMostSpecific();
3309 }
3310
3311 // Returns a list of "root" Method objects. These Method objects must NOT
3312 // be propagated to the outside world, but must instead be copied
3313 // via ReflectionFactory.copyMethod.
3314 private PublicMethods.MethodList getMethodsRecursive(String name,
3315 Class<?>[] parameterTypes,
3316 boolean includeStatic) {
3317 // 1st check declared public methods
3318 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
3319 PublicMethods.MethodList res = PublicMethods.MethodList
3320 .filter(methods, name, parameterTypes, includeStatic);
3321 // if there is at least one match among declared methods, we need not
3322 // search any further as such match surely overrides matching methods
3323 // declared in superclass(es) or interface(s).
3324 if (res != null) {
3325 return res;
3326 }
3327
3328 // if there was no match among declared methods,
3329 // we must consult the superclass (if any) recursively...
3330 Class<?> sc = getSuperclass();
3331 if (sc != null) {
3332 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic);
3333 }
3334
3335 // ...and coalesce the superclass methods with methods obtained
3336 // from directly implemented interfaces excluding static methods...
3337 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3338 res = PublicMethods.MethodList.merge(
3339 res, intf.getMethodsRecursive(name, parameterTypes,
3340 /* includeStatic */ false));
3341 }
3342
3343 return res;
3344 }
3345
3346 // Returns a "root" Constructor object. This Constructor object must NOT
3347 // be propagated to the outside world, but must instead be copied
3348 // via ReflectionFactory.copyConstructor.
3349 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3350 int which) throws NoSuchMethodException
3351 {
3352 ReflectionFactory fact = getReflectionFactory();
3353 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3354 for (Constructor<T> constructor : constructors) {
3355 if (arrayContentsEq(parameterTypes,
3356 fact.getExecutableSharedParameterTypes(constructor))) {
3357 return constructor;
3358 }
3359 }
3360 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3361 }
3362
3363 //
3364 // Other helpers and base implementation
3365 //
3366
3367 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3368 if (a1 == null) {
3369 return a2 == null || a2.length == 0;
3370 }
3371
3372 if (a2 == null) {
3373 return a1.length == 0;
3374 }
3375
3376 if (a1.length != a2.length) {
3377 return false;
3378 }
3379
3380 for (int i = 0; i < a1.length; i++) {
3381 if (a1[i] != a2[i]) {
3382 return false;
3383 }
3384 }
3385
3386 return true;
3387 }
3388
3389 private static Field[] copyFields(Field[] arg) {
3390 Field[] out = new Field[arg.length];
3391 ReflectionFactory fact = getReflectionFactory();
3392 for (int i = 0; i < arg.length; i++) {
3393 out[i] = fact.copyField(arg[i]);
3394 }
3395 return out;
3396 }
3397
3398 private static Method[] copyMethods(Method[] arg) {
3399 Method[] out = new Method[arg.length];
3400 ReflectionFactory fact = getReflectionFactory();
3401 for (int i = 0; i < arg.length; i++) {
3402 out[i] = fact.copyMethod(arg[i]);
3403 }
3404 return out;
3405 }
3406
3407 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3408 Constructor<U>[] out = arg.clone();
3409 ReflectionFactory fact = getReflectionFactory();
3410 for (int i = 0; i < out.length; i++) {
3411 out[i] = fact.copyConstructor(out[i]);
3412 }
3413 return out;
3414 }
3415
3416 private native Field[] getDeclaredFields0(boolean publicOnly);
3417 private native Method[] getDeclaredMethods0(boolean publicOnly);
3418 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3419 private native Class<?>[] getDeclaredClasses0();
3420
3421 /**
3422 * Helper method to get the method name from arguments.
3423 */
3424 private String methodToString(String name, Class<?>[] argTypes) {
3425 return getName() + '.' + name +
3426 ((argTypes == null || argTypes.length == 0) ?
3427 "()" :
3428 Arrays.stream(argTypes)
3429 .map(c -> c == null ? "null" : c.getName())
3430 .collect(Collectors.joining(",", "(", ")")));
3431 }
3432
3433 /** use serialVersionUID from JDK 1.1 for interoperability */
3434 @java.io.Serial
3435 private static final long serialVersionUID = 3206093459760846163L;
3436
3437
3438 /**
3439 * Class Class is special cased within the Serialization Stream Protocol.
3440 *
3441 * A Class instance is written initially into an ObjectOutputStream in the
3442 * following format:
3443 * <pre>
3444 * {@code TC_CLASS} ClassDescriptor
3445 * A ClassDescriptor is a special cased serialization of
3446 * a {@code java.io.ObjectStreamClass} instance.
3447 * </pre>
3448 * A new handle is generated for the initial time the class descriptor
3449 * is written into the stream. Future references to the class descriptor
3450 * are written as references to the initial class descriptor instance.
3451 *
3452 * @see java.io.ObjectStreamClass
3453 */
3454 @java.io.Serial
3455 private static final ObjectStreamField[] serialPersistentFields =
3456 new ObjectStreamField[0];
3457
3458
3459 /**
3460 * Returns the assertion status that would be assigned to this
3461 * class if it were to be initialized at the time this method is invoked.
3462 * If this class has had its assertion status set, the most recent
3463 * setting will be returned; otherwise, if any package default assertion
3464 * status pertains to this class, the most recent setting for the most
3465 * specific pertinent package default assertion status is returned;
3466 * otherwise, if this class is not a system class (i.e., it has a
3467 * class loader) its class loader's default assertion status is returned;
3468 * otherwise, the system class default assertion status is returned.
3469 * <p>
3470 * Few programmers will have any need for this method; it is provided
3471 * for the benefit of the JRE itself. (It allows a class to determine at
3472 * the time that it is initialized whether assertions should be enabled.)
3473 * Note that this method is not guaranteed to return the actual
3474 * assertion status that was (or will be) associated with the specified
3475 * class when it was (or will be) initialized.
3476 *
3477 * @return the desired assertion status of the specified class.
3478 * @see java.lang.ClassLoader#setClassAssertionStatus
3479 * @see java.lang.ClassLoader#setPackageAssertionStatus
3480 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3481 * @since 1.4
3482 */
3483 public boolean desiredAssertionStatus() {
3484 ClassLoader loader = getClassLoader0();
3485 // If the loader is null this is a system class, so ask the VM
3486 if (loader == null)
3487 return desiredAssertionStatus0(this);
3488
3489 // If the classloader has been initialized with the assertion
3490 // directives, ask it. Otherwise, ask the VM.
3491 synchronized(loader.assertionLock) {
3492 if (loader.classAssertionStatus != null) {
3493 return loader.desiredAssertionStatus(getName());
3494 }
3495 }
3496 return desiredAssertionStatus0(this);
3497 }
3498
3499 // Retrieves the desired assertion status of this class from the VM
3500 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3501
3502 /**
3503 * Returns true if and only if this class was declared as an enum in the
3504 * source code.
3505 *
3506 * Note that if an enum constant is declared with a class body,
3507 * the class of that enum constant object is an anonymous class
3508 * and <em>not</em> the class of the declaring enum type. The
3509 * {@link Enum#getDeclaringClass} method of an enum constant can
3510 * be used to get the class of the enum type declaring the
3511 * constant.
3512 *
3513 * @return true if and only if this class was declared as an enum in the
3514 * source code
3515 * @since 1.5
3516 * @jls 8.9.1 Enum Constants
3517 */
3518 public boolean isEnum() {
3519 // An enum must both directly extend java.lang.Enum and have
3520 // the ENUM bit set; classes for specialized enum constants
3521 // don't do the former.
3522 return (this.getModifiers() & ENUM) != 0 &&
3523 this.getSuperclass() == java.lang.Enum.class;
3524 }
3525
3526 // Fetches the factory for reflective objects
3527 private static ReflectionFactory getReflectionFactory() {
3528 if (reflectionFactory == null) {
3529 reflectionFactory =
3530 java.security.AccessController.doPrivileged
3531 (new ReflectionFactory.GetReflectionFactoryAction());
3532 }
3533 return reflectionFactory;
3534 }
3535 private static ReflectionFactory reflectionFactory;
3536
3537 /**
3538 * Returns the elements of this enum class or null if this
3539 * Class object does not represent an enum type.
3540 *
3541 * @return an array containing the values comprising the enum class
3542 * represented by this Class object in the order they're
3543 * declared, or null if this Class object does not
3544 * represent an enum type
3545 * @since 1.5
3546 */
3547 public T[] getEnumConstants() {
3548 T[] values = getEnumConstantsShared();
3549 return (values != null) ? values.clone() : null;
3550 }
3551
3552 /**
3553 * Returns the elements of this enum class or null if this
3554 * Class object does not represent an enum type;
3555 * identical to getEnumConstants except that the result is
3556 * uncloned, cached, and shared by all callers.
3557 */
3558 T[] getEnumConstantsShared() {
3559 T[] constants = enumConstants;
3560 if (constants == null) {
3561 if (!isEnum()) return null;
3562 try {
3563 final Method values = getMethod("values");
3564 java.security.AccessController.doPrivileged(
3565 new java.security.PrivilegedAction<>() {
3566 public Void run() {
3567 values.setAccessible(true);
3568 return null;
3569 }
3570 });
3571 @SuppressWarnings("unchecked")
3572 T[] temporaryConstants = (T[])values.invoke(null);
3573 enumConstants = constants = temporaryConstants;
3574 }
3575 // These can happen when users concoct enum-like classes
3576 // that don't comply with the enum spec.
3577 catch (InvocationTargetException | NoSuchMethodException |
3578 IllegalAccessException ex) { return null; }
3579 }
3580 return constants;
3581 }
3582 private transient volatile T[] enumConstants;
3583
3584 /**
3585 * Returns a map from simple name to enum constant. This package-private
3586 * method is used internally by Enum to implement
3587 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3588 * efficiently. Note that the map is returned by this method is
3589 * created lazily on first use. Typically it won't ever get created.
3590 */
3591 Map<String, T> enumConstantDirectory() {
3592 Map<String, T> directory = enumConstantDirectory;
3593 if (directory == null) {
3594 T[] universe = getEnumConstantsShared();
3595 if (universe == null)
3596 throw new IllegalArgumentException(
3597 getName() + " is not an enum type");
3598 directory = new HashMap<>((int)(universe.length / 0.75f) + 1);
3599 for (T constant : universe) {
3600 directory.put(((Enum<?>)constant).name(), constant);
3601 }
3602 enumConstantDirectory = directory;
3603 }
3604 return directory;
3605 }
3606 private transient volatile Map<String, T> enumConstantDirectory;
3607
3608 /**
3609 * Casts an object to the class or interface represented
3610 * by this {@code Class} object.
3611 *
3612 * @param obj the object to be cast
3613 * @return the object after casting, or null if obj is null
3614 *
3615 * @throws ClassCastException if the object is not
3616 * null and is not assignable to the type T.
3617 *
3618 * @since 1.5
3619 */
3620 @SuppressWarnings("unchecked")
3621 @HotSpotIntrinsicCandidate
3622 public T cast(Object obj) {
3623 if (obj != null && !isInstance(obj))
3624 throw new ClassCastException(cannotCastMsg(obj));
3625 return (T) obj;
3626 }
3627
3628 private String cannotCastMsg(Object obj) {
3629 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3630 }
3631
3632 /**
3633 * Casts this {@code Class} object to represent a subclass of the class
3634 * represented by the specified class object. Checks that the cast
3635 * is valid, and throws a {@code ClassCastException} if it is not. If
3636 * this method succeeds, it always returns a reference to this class object.
3637 *
3638 * <p>This method is useful when a client needs to "narrow" the type of
3639 * a {@code Class} object to pass it to an API that restricts the
3640 * {@code Class} objects that it is willing to accept. A cast would
3641 * generate a compile-time warning, as the correctness of the cast
3642 * could not be checked at runtime (because generic types are implemented
3643 * by erasure).
3644 *
3645 * @param <U> the type to cast this class object to
3646 * @param clazz the class of the type to cast this class object to
3647 * @return this {@code Class} object, cast to represent a subclass of
3648 * the specified class object.
3649 * @throws ClassCastException if this {@code Class} object does not
3650 * represent a subclass of the specified class (here "subclass" includes
3651 * the class itself).
3652 * @since 1.5
3653 */
3654 @SuppressWarnings("unchecked")
3655 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3656 if (clazz.isAssignableFrom(this))
3657 return (Class<? extends U>) this;
3658 else
3659 throw new ClassCastException(this.toString());
3660 }
3661
3662 /**
3663 * @throws NullPointerException {@inheritDoc}
3664 * @since 1.5
3665 */
3666 @SuppressWarnings("unchecked")
3667 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3668 Objects.requireNonNull(annotationClass);
3669
3670 return (A) annotationData().annotations.get(annotationClass);
3671 }
3672
3673 /**
3674 * {@inheritDoc}
3675 * @throws NullPointerException {@inheritDoc}
3676 * @since 1.5
3677 */
3678 @Override
3679 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3680 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3681 }
3682
3683 /**
3684 * @throws NullPointerException {@inheritDoc}
3685 * @since 1.8
3686 */
3687 @Override
3688 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3689 Objects.requireNonNull(annotationClass);
3690
3691 AnnotationData annotationData = annotationData();
3692 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3693 this,
3694 annotationClass);
3695 }
3696
3697 /**
3698 * @since 1.5
3699 */
3700 public Annotation[] getAnnotations() {
3701 return AnnotationParser.toArray(annotationData().annotations);
3702 }
3703
3704 /**
3705 * @throws NullPointerException {@inheritDoc}
3706 * @since 1.8
3707 */
3708 @Override
3709 @SuppressWarnings("unchecked")
3710 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3711 Objects.requireNonNull(annotationClass);
3712
3713 return (A) annotationData().declaredAnnotations.get(annotationClass);
3714 }
3715
3716 /**
3717 * @throws NullPointerException {@inheritDoc}
3718 * @since 1.8
3719 */
3720 @Override
3721 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3722 Objects.requireNonNull(annotationClass);
3723
3724 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3725 annotationClass);
3726 }
3727
3728 /**
3729 * @since 1.5
3730 */
3731 public Annotation[] getDeclaredAnnotations() {
3732 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3733 }
3734
3735 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3736 private static class AnnotationData {
3737 final Map<Class<? extends Annotation>, Annotation> annotations;
3738 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3739
3740 // Value of classRedefinedCount when we created this AnnotationData instance
3741 final int redefinedCount;
3742
3743 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3744 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3745 int redefinedCount) {
3746 this.annotations = annotations;
3747 this.declaredAnnotations = declaredAnnotations;
3748 this.redefinedCount = redefinedCount;
3749 }
3750 }
3751
3752 // Annotations cache
3753 @SuppressWarnings("UnusedDeclaration")
3754 private transient volatile AnnotationData annotationData;
3755
3756 private AnnotationData annotationData() {
3757 while (true) { // retry loop
3758 AnnotationData annotationData = this.annotationData;
3759 int classRedefinedCount = this.classRedefinedCount;
3760 if (annotationData != null &&
3761 annotationData.redefinedCount == classRedefinedCount) {
3762 return annotationData;
3763 }
3764 // null or stale annotationData -> optimistically create new instance
3765 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3766 // try to install it
3767 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3768 // successfully installed new AnnotationData
3769 return newAnnotationData;
3770 }
3771 }
3772 }
3773
3774 private AnnotationData createAnnotationData(int classRedefinedCount) {
3775 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3776 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3777 Class<?> superClass = getSuperclass();
3778 Map<Class<? extends Annotation>, Annotation> annotations = null;
3779 if (superClass != null) {
3780 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3781 superClass.annotationData().annotations;
3782 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3783 Class<? extends Annotation> annotationClass = e.getKey();
3784 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3785 if (annotations == null) { // lazy construction
3786 annotations = new LinkedHashMap<>((Math.max(
3787 declaredAnnotations.size(),
3788 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3789 ) * 4 + 2) / 3
3790 );
3791 }
3792 annotations.put(annotationClass, e.getValue());
3793 }
3794 }
3795 }
3796 if (annotations == null) {
3797 // no inherited annotations -> share the Map with declaredAnnotations
3798 annotations = declaredAnnotations;
3799 } else {
3800 // at least one inherited annotation -> declared may override inherited
3801 annotations.putAll(declaredAnnotations);
3802 }
3803 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3804 }
3805
3806 // Annotation types cache their internal (AnnotationType) form
3807
3808 @SuppressWarnings("UnusedDeclaration")
3809 private transient volatile AnnotationType annotationType;
3810
3811 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3812 return Atomic.casAnnotationType(this, oldType, newType);
3813 }
3814
3815 AnnotationType getAnnotationType() {
3816 return annotationType;
3817 }
3818
3819 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3820 return annotationData().declaredAnnotations;
3821 }
3822
3823 /* Backing store of user-defined values pertaining to this class.
3824 * Maintained by the ClassValue class.
3825 */
3826 transient ClassValue.ClassValueMap classValueMap;
3827
3828 /**
3829 * Returns an {@code AnnotatedType} object that represents the use of a
3830 * type to specify the superclass of the entity represented by this {@code
3831 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3832 * in '... extends Foo' is distinct from the <em>declaration</em> of type
3833 * Foo.)
3834 *
3835 * <p> If this {@code Class} object represents a type whose declaration
3836 * does not explicitly indicate an annotated superclass, then the return
3837 * value is an {@code AnnotatedType} object representing an element with no
3838 * annotations.
3839 *
3840 * <p> If this {@code Class} represents either the {@code Object} class, an
3841 * interface type, an array type, a primitive type, or void, the return
3842 * value is {@code null}.
3843 *
3844 * @return an object representing the superclass
3845 * @since 1.8
3846 */
3847 public AnnotatedType getAnnotatedSuperclass() {
3848 if (this == Object.class ||
3849 isInterface() ||
3850 isArray() ||
3851 isPrimitive() ||
3852 this == Void.TYPE) {
3853 return null;
3854 }
3855
3856 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3857 }
3858
3859 /**
3860 * Returns an array of {@code AnnotatedType} objects that represent the use
3861 * of types to specify superinterfaces of the entity represented by this
3862 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3863 * superinterface in '... implements Foo' is distinct from the
3864 * <em>declaration</em> of type Foo.)
3865 *
3866 * <p> If this {@code Class} object represents a class, the return value is
3867 * an array containing objects representing the uses of interface types to
3868 * specify interfaces implemented by the class. The order of the objects in
3869 * the array corresponds to the order of the interface types used in the
3870 * 'implements' clause of the declaration of this {@code Class} object.
3871 *
3872 * <p> If this {@code Class} object represents an interface, the return
3873 * value is an array containing objects representing the uses of interface
3874 * types to specify interfaces directly extended by the interface. The
3875 * order of the objects in the array corresponds to the order of the
3876 * interface types used in the 'extends' clause of the declaration of this
3877 * {@code Class} object.
3878 *
3879 * <p> If this {@code Class} object represents a class or interface whose
3880 * declaration does not explicitly indicate any annotated superinterfaces,
3881 * the return value is an array of length 0.
3882 *
3883 * <p> If this {@code Class} object represents either the {@code Object}
3884 * class, an array type, a primitive type, or void, the return value is an
3885 * array of length 0.
3886 *
3887 * @return an array representing the superinterfaces
3888 * @since 1.8
3889 */
3890 public AnnotatedType[] getAnnotatedInterfaces() {
3891 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3892 }
3893
3894 private native Class<?> getNestHost0();
3895
3896 /**
3897 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3898 * or interface represented by this {@code Class} object belongs.
3899 * Every class and interface is a member of exactly one nest.
3900 * A class or interface that is not recorded as belonging to a nest
3901 * belongs to the nest consisting only of itself, and is the nest
3902 * host.
3903 *
3904 * <p>Each of the {@code Class} objects representing array types,
3905 * primitive types, and {@code void} returns {@code this} to indicate
3906 * that the represented entity belongs to the nest consisting only of
3907 * itself, and is the nest host.
3908 *
3909 * <p>If there is a {@linkplain LinkageError linkage error} accessing
3910 * the nest host, or if this class or interface is not enumerated as
3911 * a member of the nest by the nest host, then it is considered to belong
3912 * to its own nest and {@code this} is returned as the host.
3913 *
3914 * @apiNote A {@code class} file of version 55.0 or greater may record the
3915 * host of the nest to which it belongs by using the {@code NestHost}
3916 * attribute (JVMS 4.7.28). Alternatively, a {@code class} file of
3917 * version 55.0 or greater may act as a nest host by enumerating the nest's
3918 * other members with the
3919 * {@code NestMembers} attribute (JVMS 4.7.29).
3920 * A {@code class} file of version 54.0 or lower does not use these
3921 * attributes.
3922 *
3923 * @return the nest host of this class or interface
3924 *
3925 * @throws SecurityException
3926 * If the returned class is not the current class, and
3927 * if a security manager, <i>s</i>, is present and the caller's
3928 * class loader is not the same as or an ancestor of the class
3929 * loader for the returned class and invocation of {@link
3930 * SecurityManager#checkPackageAccess s.checkPackageAccess()}
3931 * denies access to the package of the returned class
3932 * @since 11
3933 * @jvms 4.7.28 The {@code NestHost} Attribute
3934 * @jvms 4.7.29 The {@code NestMembers} Attribute
3935 * @jvms 5.4.4 Access Control
3936 */
3937 @CallerSensitive
3938 public Class<?> getNestHost() {
3939 if (isPrimitive() || isArray()) {
3940 return this;
3941 }
3942 Class<?> host;
3943 try {
3944 host = getNestHost0();
3945 } catch (LinkageError e) {
3946 // if we couldn't load our nest-host then we
3947 // act as-if we have no nest-host attribute
3948 return this;
3949 }
3950 // if null then nest membership validation failed, so we
3951 // act as-if we have no nest-host attribute
3952 if (host == null || host == this) {
3953 return this;
3954 }
3955 // returning a different class requires a security check
3956 SecurityManager sm = System.getSecurityManager();
3957 if (sm != null) {
3958 checkPackageAccess(sm,
3959 ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
3960 }
3961 return host;
3962 }
3963
3964 /**
3965 * Determines if the given {@code Class} is a nestmate of the
3966 * class or interface represented by this {@code Class} object.
3967 * Two classes or interfaces are nestmates
3968 * if they have the same {@linkplain #getNestHost() nest host}.
3969 *
3970 * @param c the class to check
3971 * @return {@code true} if this class and {@code c} are members of
3972 * the same nest; and {@code false} otherwise.
3973 *
3974 * @since 11
3975 */
3976 public boolean isNestmateOf(Class<?> c) {
3977 if (this == c) {
3978 return true;
3979 }
3980 if (isPrimitive() || isArray() ||
3981 c.isPrimitive() || c.isArray()) {
3982 return false;
3983 }
3984 try {
3985 return getNestHost0() == c.getNestHost0();
3986 } catch (LinkageError e) {
3987 return false;
3988 }
3989 }
3990
3991 private native Class<?>[] getNestMembers0();
3992
3993 /**
3994 * Returns an array containing {@code Class} objects representing all the
3995 * classes and interfaces that are members of the nest to which the class
3996 * or interface represented by this {@code Class} object belongs.
3997 * The {@linkplain #getNestHost() nest host} of that nest is the zeroth
3998 * element of the array. Subsequent elements represent any classes or
3999 * interfaces that are recorded by the nest host as being members of
4000 * the nest; the order of such elements is unspecified. Duplicates are
4001 * permitted.
4002 * If the nest host of that nest does not enumerate any members, then the
4003 * array has a single element containing {@code this}.
4004 *
4005 * <p>Each of the {@code Class} objects representing array types,
4006 * primitive types, and {@code void} returns an array containing only
4007 * {@code this}.
4008 *
4009 * <p>This method validates that, for each class or interface which is
4010 * recorded as a member of the nest by the nest host, that class or
4011 * interface records itself as a member of that same nest. Any exceptions
4012 * that occur during this validation are rethrown by this method.
4013 *
4014 * @return an array of all classes and interfaces in the same nest as
4015 * this class
4016 *
4017 * @throws LinkageError
4018 * If there is any problem loading or validating a nest member or
4019 * its nest host
4020 * @throws SecurityException
4021 * If any returned class is not the current class, and
4022 * if a security manager, <i>s</i>, is present and the caller's
4023 * class loader is not the same as or an ancestor of the class
4024 * loader for that returned class and invocation of {@link
4025 * SecurityManager#checkPackageAccess s.checkPackageAccess()}
4026 * denies access to the package of that returned class
4027 *
4028 * @since 11
4029 * @see #getNestHost()
4030 */
4031 @CallerSensitive
4032 public Class<?>[] getNestMembers() {
4033 if (isPrimitive() || isArray()) {
4034 return new Class<?>[] { this };
4035 }
4036 Class<?>[] members = getNestMembers0();
4037 // Can't actually enable this due to bootstrapping issues
4038 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
4039
4040 if (members.length > 1) {
4041 // If we return anything other than the current class we need
4042 // a security check
4043 SecurityManager sm = System.getSecurityManager();
4044 if (sm != null) {
4045 checkPackageAccess(sm,
4046 ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
4047 }
4048 }
4049 return members;
4050 }
4051
4052 /**
4053 * Returns the type descriptor string for this class.
4054 * <p>
4055 * Note that this is not a strict inverse of {@link #forName};
4056 * distinct classes which share a common name but have different class loaders
4057 * will have identical descriptor strings.
4058 *
4059 * @return the type descriptor representation
4060 * @jvms 4.3.2 Field Descriptors
4061 * @since 12
4062 */
4063 @Override
4064 public String descriptorString() {
4065 if (isPrimitive())
4066 return Wrapper.forPrimitiveType(this).basicTypeString();
4067 else if (isArray()) {
4068 return "[" + componentType.descriptorString();
4069 }
4070 else {
4071 return "L" + getName().replace('.', '/') + ";";
4072 }
4073 }
4074
4075 /**
4076 * Returns the component type of this {@code Class}, if it describes
4077 * an array type, or {@code null} otherwise.
4078 *
4079 * @implSpec
4080 * Equivalent to {@link Class#getComponentType()}.
4081 *
4082 * @return a {@code Class} describing the component type, or {@code null}
4083 * if this {@code Class} does not describe an array type
4084 * @since 12
4085 */
4086 @Override
4087 public Class<?> componentType() {
4088 return isArray() ? componentType : null;
4089 }
4090
4091 /**
4092 * Returns a {@code Class} for an array type whose component type
4093 * is described by this {@linkplain Class}.
4094 *
4095 * @return a {@code Class} describing the array type
4096 * @since 12
4097 */
4098 @Override
4099 public Class<?> arrayType() {
4100 return Array.newInstance(this, 0).getClass();
4101 }
4102
4103 /**
4104 * Returns a nominal descriptor for this instance, if one can be
4105 * constructed, or an empty {@link Optional} if one cannot be.
4106 *
4107 * @return An {@link Optional} containing the resulting nominal descriptor,
4108 * or an empty {@link Optional} if one cannot be constructed.
4109 * @since 12
4110 */
4111 @Override
4112 public Optional<ClassDesc> describeConstable() {
4113 return Optional.of(ClassDesc.ofDescriptor(descriptorString()));
4114 }
4115 }