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 @CallerSensitive
330 public static Class<?> forName(String className)
331 throws ClassNotFoundException {
332 Class<?> caller = Reflection.getCallerClass();
333 return forName0(className, true, ClassLoader.getClassLoader(caller), caller);
334 }
335
336
337 /**
338 * Returns the {@code Class} object associated with the class or
339 * interface with the given string name, using the given class loader.
340 * Given the fully qualified name for a class or interface (in the same
341 * format returned by {@code getName}) this method attempts to
342 * locate, load, and link the class or interface. The specified class
343 * loader is used to load the class or interface. If the parameter
344 * {@code loader} is null, the class is loaded through the bootstrap
345 * class loader. The class is initialized only if the
346 * {@code initialize} parameter is {@code true} and if it has
347 * not been initialized earlier.
348 *
349 * <p> If {@code name} denotes a primitive type or void, an attempt
350 * will be made to locate a user-defined class in the unnamed package whose
351 * name is {@code name}. Therefore, this method cannot be used to
352 * obtain any of the {@code Class} objects representing primitive
353 * types or void.
354 *
355 * <p> If {@code name} denotes an array class, the component type of
356 * the array class is loaded but not initialized.
357 *
358 * <p> For example, in an instance method the expression:
359 *
360 * <blockquote>
361 * {@code Class.forName("Foo")}
362 * </blockquote>
363 *
364 * is equivalent to:
365 *
366 * <blockquote>
367 * {@code Class.forName("Foo", true, this.getClass().getClassLoader())}
368 * </blockquote>
369 *
370 * Note that this method throws errors related to loading, linking or
371 * initializing as specified in Sections 12.2, 12.3 and 12.4 of <em>The
372 * Java Language Specification</em>.
373 * Note that this method does not check whether the requested class
374 * is accessible to its caller.
375 *
376 * @param name fully qualified name of the desired class
377 * @param initialize if {@code true} the class will be initialized.
378 * See Section 12.4 of <em>The Java Language Specification</em>.
379 * @param loader class loader from which the class must be loaded
380 * @return class object representing the desired class
381 *
382 * @throws LinkageError if the linkage fails
383 * @throws ExceptionInInitializerError if the initialization provoked
384 * by this method fails
385 * @throws ClassNotFoundException if the class cannot be located by
386 * the specified class loader
387 * @throws SecurityException
388 * if a security manager is present, and the {@code loader} is
389 * {@code null}, and the caller's class loader is not
390 * {@code null}, and the caller does not have the
391 * {@link RuntimePermission}{@code ("getClassLoader")}
392 *
393 * @see java.lang.Class#forName(String)
394 * @see java.lang.ClassLoader
395 *
396 * @jls 12.2 Loading of Classes and Interfaces
397 * @jls 12.3 Linking of Classes and Interfaces
398 * @jls 12.4 Initialization of Classes and Interfaces
399 * @since 1.2
400 */
401 @CallerSensitive
402 public static Class<?> forName(String name, boolean initialize,
403 ClassLoader loader)
404 throws ClassNotFoundException
405 {
406 Class<?> caller = null;
407 SecurityManager sm = System.getSecurityManager();
408 if (sm != null) {
409 // Reflective call to get caller class is only needed if a security manager
410 // is present. Avoid the overhead of making this call otherwise.
411 caller = Reflection.getCallerClass();
412 if (loader == null) {
413 ClassLoader ccl = ClassLoader.getClassLoader(caller);
414 if (ccl != null) {
415 sm.checkPermission(
416 SecurityConstants.GET_CLASSLOADER_PERMISSION);
417 }
418 }
419 }
420 return forName0(name, initialize, loader, caller);
421 }
422
423 /** Called after security check for system loader access checks have been made. */
424 private static native Class<?> forName0(String name, boolean initialize,
425 ClassLoader loader,
426 Class<?> caller)
427 throws ClassNotFoundException;
428
429
430 /**
431 * Returns the {@code Class} with the given <a href="ClassLoader.html#binary-name">
432 * binary name</a> in the given module.
433 *
434 * <p> This method attempts to locate, load, and link the class or interface.
435 * It does not run the class initializer. If the class is not found, this
436 * method returns {@code null}. </p>
437 *
438 * <p> If the class loader of the given module defines other modules and
439 * the given name is a class defined in a different module, this method
440 * returns {@code null} after the class is loaded. </p>
441 *
442 * <p> This method does not check whether the requested class is
443 * accessible to its caller. </p>
444 *
445 * <p> Note that this method throws errors related to loading and linking as
446 * specified in Sections 12.2 and 12.3 of <em>The Java Language
447 * Specification</em>.
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 Class<?> ret;
502 if (cl != null) {
503 ret = cl.loadClass(module, name);
504 } else {
505 ret = BootLoader.loadClass(module, name);
506 }
507 if (ret != null) {
508 // The loaded class should also be linked
509 linkClass(ret);
510 }
511 return ret;
512 }
513
514 private static native void linkClass(Class<?> c);
515
516 /**
517 * Creates a new instance of the class represented by this {@code Class}
518 * object. The class is instantiated as if by a {@code new}
519 * expression with an empty argument list. The class is initialized if it
520 * has not already been initialized.
521 *
522 * @deprecated This method propagates any exception thrown by the
523 * nullary constructor, including a checked exception. Use of
524 * this method effectively bypasses the compile-time exception
525 * checking that would otherwise be performed by the compiler.
526 * The {@link
527 * java.lang.reflect.Constructor#newInstance(java.lang.Object...)
528 * Constructor.newInstance} method avoids this problem by wrapping
529 * any exception thrown by the constructor in a (checked) {@link
530 * java.lang.reflect.InvocationTargetException}.
531 *
532 * <p>The call
533 *
534 * <pre>{@code
535 * clazz.newInstance()
536 * }</pre>
537 *
538 * can be replaced by
539 *
540 * <pre>{@code
541 * clazz.getDeclaredConstructor().newInstance()
542 * }</pre>
543 *
544 * The latter sequence of calls is inferred to be able to throw
545 * the additional exception types {@link
546 * InvocationTargetException} and {@link
547 * NoSuchMethodException}. Both of these exception types are
548 * subclasses of {@link ReflectiveOperationException}.
549 *
550 * @return a newly allocated instance of the class represented by this
551 * object.
552 * @throws IllegalAccessException if the class or its nullary
553 * constructor is not accessible.
554 * @throws InstantiationException
555 * if this {@code Class} represents an abstract class,
556 * an interface, an array class, a primitive type, or void;
557 * or if the class has no nullary constructor;
558 * or if the instantiation fails for some other reason.
559 * @throws ExceptionInInitializerError if the initialization
560 * provoked by this method fails.
561 * @throws SecurityException
562 * If a security manager, <i>s</i>, is present and
563 * the caller's class loader is not the same as or an
564 * ancestor of the class loader for the current class and
565 * invocation of {@link SecurityManager#checkPackageAccess
566 * s.checkPackageAccess()} denies access to the package
567 * of this class.
568 */
569 @CallerSensitive
570 @Deprecated(since="9")
571 public T newInstance()
572 throws InstantiationException, IllegalAccessException
573 {
574 SecurityManager sm = System.getSecurityManager();
575 if (sm != null) {
576 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false);
577 }
578
579 // Constructor lookup
580 Constructor<T> tmpConstructor = cachedConstructor;
581 if (tmpConstructor == null) {
582 if (this == Class.class) {
583 throw new IllegalAccessException(
584 "Can not call newInstance() on the Class for java.lang.Class"
585 );
586 }
587 try {
588 Class<?>[] empty = {};
589 final Constructor<T> c = getReflectionFactory().copyConstructor(
590 getConstructor0(empty, Member.DECLARED));
591 // Disable accessibility checks on the constructor
592 // access check is done with the true caller
593 java.security.AccessController.doPrivileged(
594 new java.security.PrivilegedAction<>() {
595 public Void run() {
596 c.setAccessible(true);
597 return null;
598 }
599 });
600 cachedConstructor = tmpConstructor = c;
601 } catch (NoSuchMethodException e) {
602 throw (InstantiationException)
603 new InstantiationException(getName()).initCause(e);
604 }
605 }
606
607 try {
608 Class<?> caller = Reflection.getCallerClass();
609 return getReflectionFactory().newInstance(tmpConstructor, null, caller);
610 } catch (InvocationTargetException e) {
611 Unsafe.getUnsafe().throwException(e.getTargetException());
612 // Not reached
613 return null;
614 }
615 }
616
617 private transient volatile Constructor<T> cachedConstructor;
618
619 /**
620 * Determines if the specified {@code Object} is assignment-compatible
621 * with the object represented by this {@code Class}. This method is
622 * the dynamic equivalent of the Java language {@code instanceof}
623 * operator. The method returns {@code true} if the specified
624 * {@code Object} argument is non-null and can be cast to the
625 * reference type represented by this {@code Class} object without
626 * raising a {@code ClassCastException.} It returns {@code false}
627 * otherwise.
628 *
629 * <p> Specifically, if this {@code Class} object represents a
630 * declared class, this method returns {@code true} if the specified
631 * {@code Object} argument is an instance of the represented class (or
632 * of any of its subclasses); it returns {@code false} otherwise. If
633 * this {@code Class} object represents an array class, this method
634 * returns {@code true} if the specified {@code Object} argument
635 * can be converted to an object of the array class by an identity
636 * conversion or by a widening reference conversion; it returns
637 * {@code false} otherwise. If this {@code Class} object
638 * represents an interface, this method returns {@code true} if the
639 * class or any superclass of the specified {@code Object} argument
640 * implements this interface; it returns {@code false} otherwise. If
641 * this {@code Class} object represents a primitive type, this method
642 * returns {@code false}.
643 *
644 * @param obj the object to check
645 * @return true if {@code obj} is an instance of this class
646 *
647 * @since 1.1
648 */
649 @HotSpotIntrinsicCandidate
650 public native boolean isInstance(Object obj);
651
652
653 /**
654 * Determines if the class or interface represented by this
655 * {@code Class} object is either the same as, or is a superclass or
656 * superinterface of, the class or interface represented by the specified
657 * {@code Class} parameter. It returns {@code true} if so;
658 * otherwise it returns {@code false}. If this {@code Class}
659 * object represents a primitive type, this method returns
660 * {@code true} if the specified {@code Class} parameter is
661 * exactly this {@code Class} object; otherwise it returns
662 * {@code false}.
663 *
664 * <p> Specifically, this method tests whether the type represented by the
665 * specified {@code Class} parameter can be converted to the type
666 * represented by this {@code Class} object via an identity conversion
667 * or via a widening reference conversion. See <em>The Java Language
668 * Specification</em>, sections 5.1.1 and 5.1.4 , for details.
669 *
670 * @param cls the {@code Class} object to be checked
671 * @return the {@code boolean} value indicating whether objects of the
672 * type {@code cls} can be assigned to objects of this class
673 * @throws NullPointerException if the specified Class parameter is
674 * null.
675 * @since 1.1
676 */
677 @HotSpotIntrinsicCandidate
678 public native boolean isAssignableFrom(Class<?> cls);
679
680
681 /**
682 * Determines if the specified {@code Class} object represents an
683 * interface type.
684 *
685 * @return {@code true} if this object represents an interface;
686 * {@code false} otherwise.
687 */
688 @HotSpotIntrinsicCandidate
689 public native boolean isInterface();
690
691
692 /**
693 * Determines if this {@code Class} object represents an array class.
694 *
695 * @return {@code true} if this object represents an array class;
696 * {@code false} otherwise.
697 * @since 1.1
698 */
699 @HotSpotIntrinsicCandidate
700 public native boolean isArray();
701
702
703 /**
704 * Determines if the specified {@code Class} object represents a
705 * primitive type.
706 *
707 * <p> There are nine predefined {@code Class} objects to represent
708 * the eight primitive types and void. These are created by the Java
709 * Virtual Machine, and have the same names as the primitive types that
710 * they represent, namely {@code boolean}, {@code byte},
711 * {@code char}, {@code short}, {@code int},
712 * {@code long}, {@code float}, and {@code double}.
713 *
714 * <p> These objects may only be accessed via the following public static
715 * final variables, and are the only {@code Class} objects for which
716 * this method returns {@code true}.
717 *
718 * @return true if and only if this class represents a primitive type
719 *
720 * @see java.lang.Boolean#TYPE
721 * @see java.lang.Character#TYPE
722 * @see java.lang.Byte#TYPE
723 * @see java.lang.Short#TYPE
724 * @see java.lang.Integer#TYPE
725 * @see java.lang.Long#TYPE
726 * @see java.lang.Float#TYPE
727 * @see java.lang.Double#TYPE
728 * @see java.lang.Void#TYPE
729 * @since 1.1
730 */
731 @HotSpotIntrinsicCandidate
732 public native boolean isPrimitive();
733
734 /**
735 * Returns true if this {@code Class} object represents an annotation
736 * type. Note that if this method returns true, {@link #isInterface()}
737 * would also return true, as all annotation types are also interfaces.
738 *
739 * @return {@code true} if this class object represents an annotation
740 * type; {@code false} otherwise
741 * @since 1.5
742 */
743 public boolean isAnnotation() {
744 return (getModifiers() & ANNOTATION) != 0;
745 }
746
747 /**
748 * Returns {@code true} if this class is a synthetic class;
749 * returns {@code false} otherwise.
750 * @return {@code true} if and only if this class is a synthetic class as
751 * defined by the Java Language Specification.
752 * @jls 13.1 The Form of a Binary
753 * @since 1.5
754 */
755 public boolean isSynthetic() {
756 return (getModifiers() & SYNTHETIC) != 0;
757 }
758
759 /**
760 * Returns the name of the entity (class, interface, array class,
761 * primitive type, or void) represented by this {@code Class} object,
762 * as a {@code String}.
763 *
764 * <p> If this class object represents a reference type that is not an
765 * array type then the binary name of the class is returned, as specified
766 * by
767 * <cite>The Java™ Language Specification</cite>.
768 *
769 * <p> If this class object represents a primitive type or void, then the
770 * name returned is a {@code String} equal to the Java language
771 * keyword corresponding to the primitive type or void.
772 *
773 * <p> If this class object represents a class of arrays, then the internal
774 * form of the name consists of the name of the element type preceded by
775 * one or more '{@code [}' characters representing the depth of the array
776 * nesting. The encoding of element type names is as follows:
777 *
778 * <blockquote><table class="striped">
779 * <caption style="display:none">Element types and encodings</caption>
780 * <thead>
781 * <tr><th scope="col"> Element Type <th scope="col"> Encoding
782 * </thead>
783 * <tbody style="text-align:left">
784 * <tr><th scope="row"> boolean <td style="text-align:center"> Z
785 * <tr><th scope="row"> byte <td style="text-align:center"> B
786 * <tr><th scope="row"> char <td style="text-align:center"> C
787 * <tr><th scope="row"> class or interface
788 * <td style="text-align:center"> L<i>classname</i>;
789 * <tr><th scope="row"> double <td style="text-align:center"> D
790 * <tr><th scope="row"> float <td style="text-align:center"> F
791 * <tr><th scope="row"> int <td style="text-align:center"> I
792 * <tr><th scope="row"> long <td style="text-align:center"> J
793 * <tr><th scope="row"> short <td style="text-align:center"> S
794 * </tbody>
795 * </table></blockquote>
796 *
797 * <p> The class or interface name <i>classname</i> is the binary name of
798 * the class specified above.
799 *
800 * <p> Examples:
801 * <blockquote><pre>
802 * String.class.getName()
803 * returns "java.lang.String"
804 * byte.class.getName()
805 * returns "byte"
806 * (new Object[3]).getClass().getName()
807 * returns "[Ljava.lang.Object;"
808 * (new int[3][4][5][6][7][8][9]).getClass().getName()
809 * returns "[[[[[[[I"
810 * </pre></blockquote>
811 *
812 * @return the name of the class or interface
813 * represented by this object.
814 */
815 public String getName() {
816 String name = this.name;
817 return name != null ? name : initClassName();
818 }
819
820 // Cache the name to reduce the number of calls into the VM.
821 // This field would be set by VM itself during initClassName call.
822 private transient String name;
823 private native String initClassName();
824
825 /**
826 * Returns the class loader for the class. Some implementations may use
827 * null to represent the bootstrap class loader. This method will return
828 * null in such implementations if this class was loaded by the bootstrap
829 * class loader.
830 *
831 * <p>If this object
832 * represents a primitive type or void, null is returned.
833 *
834 * @return the class loader that loaded the class or interface
835 * represented by this object.
836 * @throws SecurityException
837 * if a security manager is present, and the caller's class loader
838 * is not {@code null} and is not the same as or an ancestor of the
839 * class loader for the class whose class loader is requested,
840 * and the caller does not have the
841 * {@link RuntimePermission}{@code ("getClassLoader")}
842 * @see java.lang.ClassLoader
843 * @see SecurityManager#checkPermission
844 * @see java.lang.RuntimePermission
845 */
846 @CallerSensitive
847 @ForceInline // to ensure Reflection.getCallerClass optimization
848 public ClassLoader getClassLoader() {
849 ClassLoader cl = getClassLoader0();
850 if (cl == null)
851 return null;
852 SecurityManager sm = System.getSecurityManager();
853 if (sm != null) {
854 ClassLoader.checkClassLoaderPermission(cl, Reflection.getCallerClass());
855 }
856 return cl;
857 }
858
859 // Package-private to allow ClassLoader access
860 ClassLoader getClassLoader0() { return classLoader; }
861
862 /**
863 * Returns the module that this class or interface is a member of.
864 *
865 * If this class represents an array type then this method returns the
866 * {@code Module} for the element type. If this class represents a
867 * primitive type or void, then the {@code Module} object for the
868 * {@code java.base} module is returned.
869 *
870 * If this class is in an unnamed module then the {@linkplain
871 * ClassLoader#getUnnamedModule() unnamed} {@code Module} of the class
872 * loader for this class is returned.
873 *
874 * @return the module that this class or interface is a member of
875 *
876 * @since 9
877 * @spec JPMS
878 */
879 public Module getModule() {
880 return module;
881 }
882
883 // set by VM
884 private transient Module module;
885
886 // Initialized in JVM not by private constructor
887 // This field is filtered from reflection access, i.e. getDeclaredField
888 // will throw NoSuchFieldException
889 private final ClassLoader classLoader;
890
891 /**
892 * Returns an array of {@code TypeVariable} objects that represent the
893 * type variables declared by the generic declaration represented by this
894 * {@code GenericDeclaration} object, in declaration order. Returns an
895 * array of length 0 if the underlying generic declaration declares no type
896 * variables.
897 *
898 * @return an array of {@code TypeVariable} objects that represent
899 * the type variables declared by this generic declaration
900 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
901 * signature of this generic declaration does not conform to
902 * the format specified in
903 * <cite>The Java™ Virtual Machine Specification</cite>
904 * @since 1.5
905 */
906 @SuppressWarnings("unchecked")
907 public TypeVariable<Class<T>>[] getTypeParameters() {
908 ClassRepository info = getGenericInfo();
909 if (info != null)
910 return (TypeVariable<Class<T>>[])info.getTypeParameters();
911 else
912 return (TypeVariable<Class<T>>[])new TypeVariable<?>[0];
913 }
914
915
916 /**
917 * Returns the {@code Class} representing the direct superclass of the
918 * entity (class, interface, primitive type or void) represented by
919 * this {@code Class}. If this {@code Class} represents either the
920 * {@code Object} class, an interface, a primitive type, or void, then
921 * null is returned. If this object represents an array class then the
922 * {@code Class} object representing the {@code Object} class is
923 * returned.
924 *
925 * @return the direct superclass of the class represented by this object
926 */
927 @HotSpotIntrinsicCandidate
928 public native Class<? super T> getSuperclass();
929
930
931 /**
932 * Returns the {@code Type} representing the direct superclass of
933 * the entity (class, interface, primitive type or void) represented by
934 * this {@code Class}.
935 *
936 * <p>If the superclass is a parameterized type, the {@code Type}
937 * object returned must accurately reflect the actual type
938 * arguments used in the source code. The parameterized type
939 * representing the superclass is created if it had not been
940 * created before. See the declaration of {@link
941 * java.lang.reflect.ParameterizedType ParameterizedType} for the
942 * semantics of the creation process for parameterized types. If
943 * this {@code Class} represents either the {@code Object}
944 * class, an interface, a primitive type, or void, then null is
945 * returned. If this object represents an array class then the
946 * {@code Class} object representing the {@code Object} class is
947 * returned.
948 *
949 * @throws java.lang.reflect.GenericSignatureFormatError if the generic
950 * class signature does not conform to the format specified in
951 * <cite>The Java™ Virtual Machine Specification</cite>
952 * @throws TypeNotPresentException if the generic superclass
953 * refers to a non-existent type declaration
954 * @throws java.lang.reflect.MalformedParameterizedTypeException if the
955 * generic superclass refers to a parameterized type that cannot be
956 * instantiated for any reason
957 * @return the direct superclass of the class represented by this object
958 * @since 1.5
959 */
960 public Type getGenericSuperclass() {
961 ClassRepository info = getGenericInfo();
962 if (info == null) {
963 return getSuperclass();
964 }
965
966 // Historical irregularity:
967 // Generic signature marks interfaces with superclass = Object
968 // but this API returns null for interfaces
969 if (isInterface()) {
970 return null;
971 }
972
973 return info.getSuperclass();
974 }
975
976 /**
977 * Gets the package of this class.
978 *
979 * <p>If this class represents an array type, a primitive type or void,
980 * this method returns {@code null}.
981 *
982 * @return the package of this class.
983 * @revised 9
984 * @spec JPMS
985 */
986 public Package getPackage() {
987 if (isPrimitive() || isArray()) {
988 return null;
989 }
990 ClassLoader cl = getClassLoader0();
991 return cl != null ? cl.definePackage(this)
992 : BootLoader.definePackage(this);
993 }
994
995 /**
996 * Returns the fully qualified package name.
997 *
998 * <p> If this class is a top level class, then this method returns the fully
999 * qualified name of the package that the class is a member of, or the
1000 * empty string if the class is in an unnamed package.
1001 *
1002 * <p> If this class is a member class, then this method is equivalent to
1003 * invoking {@code getPackageName()} on the {@linkplain #getEnclosingClass
1004 * enclosing class}.
1005 *
1006 * <p> If this class is a {@linkplain #isLocalClass local class} or an {@linkplain
1007 * #isAnonymousClass() anonymous class}, then this method is equivalent to
1008 * invoking {@code getPackageName()} on the {@linkplain #getDeclaringClass
1009 * declaring class} of the {@linkplain #getEnclosingMethod enclosing method} or
1010 * {@linkplain #getEnclosingConstructor enclosing constructor}.
1011 *
1012 * <p> If this class represents an array type then this method returns the
1013 * package name of the element type. If this class represents a primitive
1014 * type or void then the package name "{@code java.lang}" is returned.
1015 *
1016 * @return the fully qualified package name
1017 *
1018 * @since 9
1019 * @spec JPMS
1020 * @jls 6.7 Fully Qualified Names
1021 */
1022 public String getPackageName() {
1023 String pn = this.packageName;
1024 if (pn == null) {
1025 Class<?> c = this;
1026 while (c.isArray()) {
1027 c = c.getComponentType();
1028 }
1029 if (c.isPrimitive()) {
1030 pn = "java.lang";
1031 } else {
1032 String cn = c.getName();
1033 int dot = cn.lastIndexOf('.');
1034 pn = (dot != -1) ? cn.substring(0, dot).intern() : "";
1035 }
1036 this.packageName = pn;
1037 }
1038 return pn;
1039 }
1040
1041 // cached package name
1042 private transient String packageName;
1043
1044 /**
1045 * Returns the interfaces directly implemented by the class or interface
1046 * represented by this object.
1047 *
1048 * <p>If this object represents a class, the return value is an array
1049 * containing objects representing all interfaces directly implemented by
1050 * the class. The order of the interface objects in the array corresponds
1051 * to the order of the interface names in the {@code implements} clause of
1052 * the declaration of the class represented by this object. For example,
1053 * given the declaration:
1054 * <blockquote>
1055 * {@code class Shimmer implements FloorWax, DessertTopping { ... }}
1056 * </blockquote>
1057 * suppose the value of {@code s} is an instance of
1058 * {@code Shimmer}; the value of the expression:
1059 * <blockquote>
1060 * {@code s.getClass().getInterfaces()[0]}
1061 * </blockquote>
1062 * is the {@code Class} object that represents interface
1063 * {@code FloorWax}; and the value of:
1064 * <blockquote>
1065 * {@code s.getClass().getInterfaces()[1]}
1066 * </blockquote>
1067 * is the {@code Class} object that represents interface
1068 * {@code DessertTopping}.
1069 *
1070 * <p>If this object represents an interface, the array contains objects
1071 * representing all interfaces directly extended by the interface. The
1072 * order of the interface objects in the array corresponds to the order of
1073 * the interface names in the {@code extends} clause of the declaration of
1074 * the interface represented by this object.
1075 *
1076 * <p>If this object represents a class or interface that implements no
1077 * interfaces, the method returns an array of length 0.
1078 *
1079 * <p>If this object represents a primitive type or void, the method
1080 * returns an array of length 0.
1081 *
1082 * <p>If this {@code Class} object represents an array type, the
1083 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1084 * returned in that order.
1085 *
1086 * @return an array of interfaces directly implemented by this class
1087 */
1088 public Class<?>[] getInterfaces() {
1089 // defensively copy before handing over to user code
1090 return getInterfaces(true);
1091 }
1092
1093 private Class<?>[] getInterfaces(boolean cloneArray) {
1094 ReflectionData<T> rd = reflectionData();
1095 if (rd == null) {
1096 // no cloning required
1097 return getInterfaces0();
1098 } else {
1099 Class<?>[] interfaces = rd.interfaces;
1100 if (interfaces == null) {
1101 interfaces = getInterfaces0();
1102 rd.interfaces = interfaces;
1103 }
1104 // defensively copy if requested
1105 return cloneArray ? interfaces.clone() : interfaces;
1106 }
1107 }
1108
1109 private native Class<?>[] getInterfaces0();
1110
1111 /**
1112 * Returns the {@code Type}s representing the interfaces
1113 * directly implemented by the class or interface represented by
1114 * this object.
1115 *
1116 * <p>If a superinterface is a parameterized type, the
1117 * {@code Type} object returned for it must accurately reflect
1118 * the actual type arguments used in the source code. The
1119 * parameterized type representing each superinterface is created
1120 * if it had not been created before. See the declaration of
1121 * {@link java.lang.reflect.ParameterizedType ParameterizedType}
1122 * for the semantics of the creation process for parameterized
1123 * types.
1124 *
1125 * <p>If this object represents a class, the return value is an array
1126 * containing objects representing all interfaces directly implemented by
1127 * the class. The order of the interface objects in the array corresponds
1128 * to the order of the interface names in the {@code implements} clause of
1129 * the declaration of the class represented by this object.
1130 *
1131 * <p>If this object represents an interface, the array contains objects
1132 * representing all interfaces directly extended by the interface. The
1133 * order of the interface objects in the array corresponds to the order of
1134 * the interface names in the {@code extends} clause of the declaration of
1135 * the interface represented by this object.
1136 *
1137 * <p>If this object represents a class or interface that implements no
1138 * interfaces, the method returns an array of length 0.
1139 *
1140 * <p>If this object represents a primitive type or void, the method
1141 * returns an array of length 0.
1142 *
1143 * <p>If this {@code Class} object represents an array type, the
1144 * interfaces {@code Cloneable} and {@code java.io.Serializable} are
1145 * returned in that order.
1146 *
1147 * @throws java.lang.reflect.GenericSignatureFormatError
1148 * if the generic class signature does not conform to the format
1149 * specified in
1150 * <cite>The Java™ Virtual Machine Specification</cite>
1151 * @throws TypeNotPresentException if any of the generic
1152 * superinterfaces refers to a non-existent type declaration
1153 * @throws java.lang.reflect.MalformedParameterizedTypeException
1154 * if any of the generic superinterfaces refer to a parameterized
1155 * type that cannot be instantiated for any reason
1156 * @return an array of interfaces directly implemented by this class
1157 * @since 1.5
1158 */
1159 public Type[] getGenericInterfaces() {
1160 ClassRepository info = getGenericInfo();
1161 return (info == null) ? getInterfaces() : info.getSuperInterfaces();
1162 }
1163
1164
1165 /**
1166 * Returns the {@code Class} representing the component type of an
1167 * array. If this class does not represent an array class this method
1168 * returns null.
1169 *
1170 * @return the {@code Class} representing the component type of this
1171 * class if this class is an array
1172 * @see java.lang.reflect.Array
1173 * @since 1.1
1174 */
1175 public Class<?> getComponentType() {
1176 // Only return for array types. Storage may be reused for Class for instance types.
1177 if (isArray()) {
1178 return componentType;
1179 } else {
1180 return null;
1181 }
1182 }
1183
1184 private final Class<?> componentType;
1185
1186
1187 /**
1188 * Returns the Java language modifiers for this class or interface, encoded
1189 * in an integer. The modifiers consist of the Java Virtual Machine's
1190 * constants for {@code public}, {@code protected},
1191 * {@code private}, {@code final}, {@code static},
1192 * {@code abstract} and {@code interface}; they should be decoded
1193 * using the methods of class {@code Modifier}.
1194 *
1195 * <p> If the underlying class is an array class, then its
1196 * {@code public}, {@code private} and {@code protected}
1197 * modifiers are the same as those of its component type. If this
1198 * {@code Class} represents a primitive type or void, its
1199 * {@code public} modifier is always {@code true}, and its
1200 * {@code protected} and {@code private} modifiers are always
1201 * {@code false}. If this object represents an array class, a
1202 * primitive type or void, then its {@code final} modifier is always
1203 * {@code true} and its interface modifier is always
1204 * {@code false}. The values of its other modifiers are not determined
1205 * by this specification.
1206 *
1207 * <p> The modifier encodings are defined in <em>The Java Virtual Machine
1208 * Specification</em>, table 4.1.
1209 *
1210 * @return the {@code int} representing the modifiers for this class
1211 * @see java.lang.reflect.Modifier
1212 * @since 1.1
1213 */
1214 @HotSpotIntrinsicCandidate
1215 public native int getModifiers();
1216
1217
1218 /**
1219 * Gets the signers of this class.
1220 *
1221 * @return the signers of this class, or null if there are no signers. In
1222 * particular, this method returns null if this object represents
1223 * a primitive type or void.
1224 * @since 1.1
1225 */
1226 public native Object[] getSigners();
1227
1228
1229 /**
1230 * Set the signers of this class.
1231 */
1232 native void setSigners(Object[] signers);
1233
1234
1235 /**
1236 * If this {@code Class} object represents a local or anonymous
1237 * class within a method, returns a {@link
1238 * java.lang.reflect.Method Method} object representing the
1239 * immediately enclosing method of the underlying class. Returns
1240 * {@code null} otherwise.
1241 *
1242 * In particular, this method returns {@code null} if the underlying
1243 * class is a local or anonymous class immediately enclosed by a type
1244 * declaration, instance initializer or static initializer.
1245 *
1246 * @return the immediately enclosing method of the underlying class, if
1247 * that class is a local or anonymous class; otherwise {@code null}.
1248 *
1249 * @throws SecurityException
1250 * If a security manager, <i>s</i>, is present and any of the
1251 * following conditions is met:
1252 *
1253 * <ul>
1254 *
1255 * <li> the caller's class loader is not the same as the
1256 * class loader of the enclosing class and invocation of
1257 * {@link SecurityManager#checkPermission
1258 * s.checkPermission} method with
1259 * {@code RuntimePermission("accessDeclaredMembers")}
1260 * denies access to the methods within the enclosing class
1261 *
1262 * <li> the caller's class loader is not the same as or an
1263 * ancestor of the class loader for the enclosing class and
1264 * invocation of {@link SecurityManager#checkPackageAccess
1265 * s.checkPackageAccess()} denies access to the package
1266 * of the enclosing class
1267 *
1268 * </ul>
1269 * @since 1.5
1270 */
1271 @CallerSensitive
1272 public Method getEnclosingMethod() throws SecurityException {
1273 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1274
1275 if (enclosingInfo == null)
1276 return null;
1277 else {
1278 if (!enclosingInfo.isMethod())
1279 return null;
1280
1281 MethodRepository typeInfo = MethodRepository.make(enclosingInfo.getDescriptor(),
1282 getFactory());
1283 Class<?> returnType = toClass(typeInfo.getReturnType());
1284 Type [] parameterTypes = typeInfo.getParameterTypes();
1285 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1286
1287 // Convert Types to Classes; returned types *should*
1288 // be class objects since the methodDescriptor's used
1289 // don't have generics information
1290 for(int i = 0; i < parameterClasses.length; i++)
1291 parameterClasses[i] = toClass(parameterTypes[i]);
1292
1293 // Perform access check
1294 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1295 SecurityManager sm = System.getSecurityManager();
1296 if (sm != null) {
1297 enclosingCandidate.checkMemberAccess(sm, Member.DECLARED,
1298 Reflection.getCallerClass(), true);
1299 }
1300 Method[] candidates = enclosingCandidate.privateGetDeclaredMethods(false);
1301
1302 /*
1303 * Loop over all declared methods; match method name,
1304 * number of and type of parameters, *and* return
1305 * type. Matching return type is also necessary
1306 * because of covariant returns, etc.
1307 */
1308 ReflectionFactory fact = getReflectionFactory();
1309 for (Method m : candidates) {
1310 if (m.getName().equals(enclosingInfo.getName()) &&
1311 arrayContentsEq(parameterClasses,
1312 fact.getExecutableSharedParameterTypes(m))) {
1313 // finally, check return type
1314 if (m.getReturnType().equals(returnType)) {
1315 return fact.copyMethod(m);
1316 }
1317 }
1318 }
1319
1320 throw new InternalError("Enclosing method not found");
1321 }
1322 }
1323
1324 private native Object[] getEnclosingMethod0();
1325
1326 private EnclosingMethodInfo getEnclosingMethodInfo() {
1327 Object[] enclosingInfo = getEnclosingMethod0();
1328 if (enclosingInfo == null)
1329 return null;
1330 else {
1331 return new EnclosingMethodInfo(enclosingInfo);
1332 }
1333 }
1334
1335 private static final class EnclosingMethodInfo {
1336 private final Class<?> enclosingClass;
1337 private final String name;
1338 private final String descriptor;
1339
1340 static void validate(Object[] enclosingInfo) {
1341 if (enclosingInfo.length != 3)
1342 throw new InternalError("Malformed enclosing method information");
1343 try {
1344 // The array is expected to have three elements:
1345
1346 // the immediately enclosing class
1347 Class<?> enclosingClass = (Class<?>)enclosingInfo[0];
1348 assert(enclosingClass != null);
1349
1350 // the immediately enclosing method or constructor's
1351 // name (can be null).
1352 String name = (String)enclosingInfo[1];
1353
1354 // the immediately enclosing method or constructor's
1355 // descriptor (null iff name is).
1356 String descriptor = (String)enclosingInfo[2];
1357 assert((name != null && descriptor != null) || name == descriptor);
1358 } catch (ClassCastException cce) {
1359 throw new InternalError("Invalid type in enclosing method information", cce);
1360 }
1361 }
1362
1363 EnclosingMethodInfo(Object[] enclosingInfo) {
1364 validate(enclosingInfo);
1365 this.enclosingClass = (Class<?>)enclosingInfo[0];
1366 this.name = (String)enclosingInfo[1];
1367 this.descriptor = (String)enclosingInfo[2];
1368 }
1369
1370 boolean isPartial() {
1371 return enclosingClass == null || name == null || descriptor == null;
1372 }
1373
1374 boolean isConstructor() { return !isPartial() && "<init>".equals(name); }
1375
1376 boolean isMethod() { return !isPartial() && !isConstructor() && !"<clinit>".equals(name); }
1377
1378 Class<?> getEnclosingClass() { return enclosingClass; }
1379
1380 String getName() { return name; }
1381
1382 String getDescriptor() { return descriptor; }
1383
1384 }
1385
1386 private static Class<?> toClass(Type o) {
1387 if (o instanceof GenericArrayType)
1388 return Array.newInstance(toClass(((GenericArrayType)o).getGenericComponentType()),
1389 0)
1390 .getClass();
1391 return (Class<?>)o;
1392 }
1393
1394 /**
1395 * If this {@code Class} object represents a local or anonymous
1396 * class within a constructor, returns a {@link
1397 * java.lang.reflect.Constructor Constructor} object representing
1398 * the immediately enclosing constructor of the underlying
1399 * class. Returns {@code null} otherwise. In particular, this
1400 * method returns {@code null} if the underlying class is a local
1401 * or anonymous class immediately enclosed by a type declaration,
1402 * instance initializer or static initializer.
1403 *
1404 * @return the immediately enclosing constructor of the underlying class, if
1405 * that class is a local or anonymous class; otherwise {@code null}.
1406 * @throws SecurityException
1407 * If a security manager, <i>s</i>, is present and any of the
1408 * following conditions is met:
1409 *
1410 * <ul>
1411 *
1412 * <li> the caller's class loader is not the same as the
1413 * class loader of the enclosing class and invocation of
1414 * {@link SecurityManager#checkPermission
1415 * s.checkPermission} method with
1416 * {@code RuntimePermission("accessDeclaredMembers")}
1417 * denies access to the constructors within the enclosing class
1418 *
1419 * <li> the caller's class loader is not the same as or an
1420 * ancestor of the class loader for the enclosing class and
1421 * invocation of {@link SecurityManager#checkPackageAccess
1422 * s.checkPackageAccess()} denies access to the package
1423 * of the enclosing class
1424 *
1425 * </ul>
1426 * @since 1.5
1427 */
1428 @CallerSensitive
1429 public Constructor<?> getEnclosingConstructor() throws SecurityException {
1430 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1431
1432 if (enclosingInfo == null)
1433 return null;
1434 else {
1435 if (!enclosingInfo.isConstructor())
1436 return null;
1437
1438 ConstructorRepository typeInfo = ConstructorRepository.make(enclosingInfo.getDescriptor(),
1439 getFactory());
1440 Type [] parameterTypes = typeInfo.getParameterTypes();
1441 Class<?>[] parameterClasses = new Class<?>[parameterTypes.length];
1442
1443 // Convert Types to Classes; returned types *should*
1444 // be class objects since the methodDescriptor's used
1445 // don't have generics information
1446 for(int i = 0; i < parameterClasses.length; i++)
1447 parameterClasses[i] = toClass(parameterTypes[i]);
1448
1449 // Perform access check
1450 final Class<?> enclosingCandidate = enclosingInfo.getEnclosingClass();
1451 SecurityManager sm = System.getSecurityManager();
1452 if (sm != null) {
1453 enclosingCandidate.checkMemberAccess(sm, Member.DECLARED,
1454 Reflection.getCallerClass(), true);
1455 }
1456
1457 Constructor<?>[] candidates = enclosingCandidate
1458 .privateGetDeclaredConstructors(false);
1459 /*
1460 * Loop over all declared constructors; match number
1461 * of and type of parameters.
1462 */
1463 ReflectionFactory fact = getReflectionFactory();
1464 for (Constructor<?> c : candidates) {
1465 if (arrayContentsEq(parameterClasses,
1466 fact.getExecutableSharedParameterTypes(c))) {
1467 return fact.copyConstructor(c);
1468 }
1469 }
1470
1471 throw new InternalError("Enclosing constructor not found");
1472 }
1473 }
1474
1475
1476 /**
1477 * If the class or interface represented by this {@code Class} object
1478 * is a member of another class, returns the {@code Class} object
1479 * representing the class in which it was declared. This method returns
1480 * null if this class or interface is not a member of any other class. If
1481 * this {@code Class} object represents an array class, a primitive
1482 * type, or void,then this method returns null.
1483 *
1484 * @return the declaring class for this class
1485 * @throws SecurityException
1486 * If a security manager, <i>s</i>, is present and the caller's
1487 * class loader is not the same as or an ancestor of the class
1488 * loader for the declaring class and invocation of {@link
1489 * SecurityManager#checkPackageAccess s.checkPackageAccess()}
1490 * denies access to the package of the declaring class
1491 * @since 1.1
1492 */
1493 @CallerSensitive
1494 public Class<?> getDeclaringClass() throws SecurityException {
1495 final Class<?> candidate = getDeclaringClass0();
1496
1497 if (candidate != null) {
1498 SecurityManager sm = System.getSecurityManager();
1499 if (sm != null) {
1500 candidate.checkPackageAccess(sm,
1501 ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
1502 }
1503 }
1504 return candidate;
1505 }
1506
1507 private native Class<?> getDeclaringClass0();
1508
1509
1510 /**
1511 * Returns the immediately enclosing class of the underlying
1512 * class. If the underlying class is a top level class this
1513 * method returns {@code null}.
1514 * @return the immediately enclosing class of the underlying class
1515 * @throws SecurityException
1516 * If a security manager, <i>s</i>, is present and the caller's
1517 * class loader is not the same as or an ancestor of the class
1518 * loader for the enclosing class and invocation of {@link
1519 * SecurityManager#checkPackageAccess s.checkPackageAccess()}
1520 * denies access to the package of the enclosing class
1521 * @since 1.5
1522 */
1523 @CallerSensitive
1524 public Class<?> getEnclosingClass() throws SecurityException {
1525 // There are five kinds of classes (or interfaces):
1526 // a) Top level classes
1527 // b) Nested classes (static member classes)
1528 // c) Inner classes (non-static member classes)
1529 // d) Local classes (named classes declared within a method)
1530 // e) Anonymous classes
1531
1532
1533 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1534 // attribute if and only if it is a local class or an
1535 // anonymous class.
1536 EnclosingMethodInfo enclosingInfo = getEnclosingMethodInfo();
1537 Class<?> enclosingCandidate;
1538
1539 if (enclosingInfo == null) {
1540 // This is a top level or a nested class or an inner class (a, b, or c)
1541 enclosingCandidate = getDeclaringClass0();
1542 } else {
1543 Class<?> enclosingClass = enclosingInfo.getEnclosingClass();
1544 // This is a local class or an anonymous class (d or e)
1545 if (enclosingClass == this || enclosingClass == null)
1546 throw new InternalError("Malformed enclosing method information");
1547 else
1548 enclosingCandidate = enclosingClass;
1549 }
1550
1551 if (enclosingCandidate != null) {
1552 SecurityManager sm = System.getSecurityManager();
1553 if (sm != null) {
1554 enclosingCandidate.checkPackageAccess(sm,
1555 ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
1556 }
1557 }
1558 return enclosingCandidate;
1559 }
1560
1561 /**
1562 * Returns the simple name of the underlying class as given in the
1563 * source code. Returns an empty string if the underlying class is
1564 * anonymous.
1565 *
1566 * <p>The simple name of an array is the simple name of the
1567 * component type with "[]" appended. In particular the simple
1568 * name of an array whose component type is anonymous is "[]".
1569 *
1570 * @return the simple name of the underlying class
1571 * @since 1.5
1572 */
1573 public String getSimpleName() {
1574 ReflectionData<T> rd = reflectionData();
1575 String simpleName = rd.simpleName;
1576 if (simpleName == null) {
1577 rd.simpleName = simpleName = getSimpleName0();
1578 }
1579 return simpleName;
1580 }
1581
1582 private String getSimpleName0() {
1583 if (isArray()) {
1584 return getComponentType().getSimpleName() + "[]";
1585 }
1586 String simpleName = getSimpleBinaryName();
1587 if (simpleName == null) { // top level class
1588 simpleName = getName();
1589 simpleName = simpleName.substring(simpleName.lastIndexOf('.') + 1); // strip the package name
1590 }
1591 return simpleName;
1592 }
1593
1594 /**
1595 * Return an informative string for the name of this type.
1596 *
1597 * @return an informative string for the name of this type
1598 * @since 1.8
1599 */
1600 public String getTypeName() {
1601 if (isArray()) {
1602 try {
1603 Class<?> cl = this;
1604 int dimensions = 0;
1605 do {
1606 dimensions++;
1607 cl = cl.getComponentType();
1608 } while (cl.isArray());
1609 return cl.getName() + "[]".repeat(dimensions);
1610 } catch (Throwable e) { /*FALLTHRU*/ }
1611 }
1612 return getName();
1613 }
1614
1615 /**
1616 * Returns the canonical name of the underlying class as
1617 * defined by the Java Language Specification. Returns null if
1618 * the underlying class does not have a canonical name (i.e., if
1619 * it is a local or anonymous class or an array whose component
1620 * type does not have a canonical name).
1621 * @return the canonical name of the underlying class if it exists, and
1622 * {@code null} otherwise.
1623 * @since 1.5
1624 */
1625 public String getCanonicalName() {
1626 ReflectionData<T> rd = reflectionData();
1627 String canonicalName = rd.canonicalName;
1628 if (canonicalName == null) {
1629 rd.canonicalName = canonicalName = getCanonicalName0();
1630 }
1631 return canonicalName == ReflectionData.NULL_SENTINEL? null : canonicalName;
1632 }
1633
1634 private String getCanonicalName0() {
1635 if (isArray()) {
1636 String canonicalName = getComponentType().getCanonicalName();
1637 if (canonicalName != null)
1638 return canonicalName + "[]";
1639 else
1640 return ReflectionData.NULL_SENTINEL;
1641 }
1642 if (isLocalOrAnonymousClass())
1643 return ReflectionData.NULL_SENTINEL;
1644 Class<?> enclosingClass = getEnclosingClass();
1645 if (enclosingClass == null) { // top level class
1646 return getName();
1647 } else {
1648 String enclosingName = enclosingClass.getCanonicalName();
1649 if (enclosingName == null)
1650 return ReflectionData.NULL_SENTINEL;
1651 return enclosingName + "." + getSimpleName();
1652 }
1653 }
1654
1655 /**
1656 * Returns {@code true} if and only if the underlying class
1657 * is an anonymous class.
1658 *
1659 * @return {@code true} if and only if this class is an anonymous class.
1660 * @since 1.5
1661 */
1662 public boolean isAnonymousClass() {
1663 return !isArray() && isLocalOrAnonymousClass() &&
1664 getSimpleBinaryName0() == null;
1665 }
1666
1667 /**
1668 * Returns {@code true} if and only if the underlying class
1669 * is a local class.
1670 *
1671 * @return {@code true} if and only if this class is a local class.
1672 * @since 1.5
1673 */
1674 public boolean isLocalClass() {
1675 return isLocalOrAnonymousClass() &&
1676 (isArray() || getSimpleBinaryName0() != null);
1677 }
1678
1679 /**
1680 * Returns {@code true} if and only if the underlying class
1681 * is a member class.
1682 *
1683 * @return {@code true} if and only if this class is a member class.
1684 * @since 1.5
1685 */
1686 public boolean isMemberClass() {
1687 return !isLocalOrAnonymousClass() && getDeclaringClass0() != null;
1688 }
1689
1690 /**
1691 * Returns the "simple binary name" of the underlying class, i.e.,
1692 * the binary name without the leading enclosing class name.
1693 * Returns {@code null} if the underlying class is a top level
1694 * class.
1695 */
1696 private String getSimpleBinaryName() {
1697 if (isTopLevelClass())
1698 return null;
1699 String name = getSimpleBinaryName0();
1700 if (name == null) // anonymous class
1701 return "";
1702 return name;
1703 }
1704
1705 private native String getSimpleBinaryName0();
1706
1707 /**
1708 * Returns {@code true} if this is a top level class. Returns {@code false}
1709 * otherwise.
1710 */
1711 private boolean isTopLevelClass() {
1712 return !isLocalOrAnonymousClass() && getDeclaringClass0() == null;
1713 }
1714
1715 /**
1716 * Returns {@code true} if this is a local class or an anonymous
1717 * class. Returns {@code false} otherwise.
1718 */
1719 private boolean isLocalOrAnonymousClass() {
1720 // JVM Spec 4.7.7: A class must have an EnclosingMethod
1721 // attribute if and only if it is a local class or an
1722 // anonymous class.
1723 return hasEnclosingMethodInfo();
1724 }
1725
1726 private boolean hasEnclosingMethodInfo() {
1727 Object[] enclosingInfo = getEnclosingMethod0();
1728 if (enclosingInfo != null) {
1729 EnclosingMethodInfo.validate(enclosingInfo);
1730 return true;
1731 }
1732 return false;
1733 }
1734
1735 /**
1736 * Returns an array containing {@code Class} objects representing all
1737 * the public classes and interfaces that are members of the class
1738 * represented by this {@code Class} object. This includes public
1739 * class and interface members inherited from superclasses and public class
1740 * and interface members declared by the class. This method returns an
1741 * array of length 0 if this {@code Class} object has no public member
1742 * classes or interfaces. This method also returns an array of length 0 if
1743 * this {@code Class} object represents a primitive type, an array
1744 * class, or void.
1745 *
1746 * @return the array of {@code Class} objects representing the public
1747 * members of this class
1748 * @throws SecurityException
1749 * If a security manager, <i>s</i>, is present and
1750 * the caller's class loader is not the same as or an
1751 * ancestor of the class loader for the current class and
1752 * invocation of {@link SecurityManager#checkPackageAccess
1753 * s.checkPackageAccess()} denies access to the package
1754 * of this class.
1755 *
1756 * @since 1.1
1757 */
1758 @CallerSensitive
1759 public Class<?>[] getClasses() {
1760 SecurityManager sm = System.getSecurityManager();
1761 if (sm != null) {
1762 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), false);
1763 }
1764
1765 // Privileged so this implementation can look at DECLARED classes,
1766 // something the caller might not have privilege to do. The code here
1767 // is allowed to look at DECLARED classes because (1) it does not hand
1768 // out anything other than public members and (2) public member access
1769 // has already been ok'd by the SecurityManager.
1770
1771 return java.security.AccessController.doPrivileged(
1772 new java.security.PrivilegedAction<>() {
1773 public Class<?>[] run() {
1774 List<Class<?>> list = new ArrayList<>();
1775 Class<?> currentClass = Class.this;
1776 while (currentClass != null) {
1777 for (Class<?> m : currentClass.getDeclaredClasses()) {
1778 if (Modifier.isPublic(m.getModifiers())) {
1779 list.add(m);
1780 }
1781 }
1782 currentClass = currentClass.getSuperclass();
1783 }
1784 return list.toArray(new Class<?>[0]);
1785 }
1786 });
1787 }
1788
1789
1790 /**
1791 * Returns an array containing {@code Field} objects reflecting all
1792 * the accessible public fields of the class or interface represented by
1793 * this {@code Class} object.
1794 *
1795 * <p> If this {@code Class} object represents a class or interface with
1796 * no accessible public fields, then this method returns an array of length
1797 * 0.
1798 *
1799 * <p> If this {@code Class} object represents a class, then this method
1800 * returns the public fields of the class and of all its superclasses and
1801 * superinterfaces.
1802 *
1803 * <p> If this {@code Class} object represents an interface, then this
1804 * method returns the fields of the interface and of all its
1805 * superinterfaces.
1806 *
1807 * <p> If this {@code Class} object represents an array type, a primitive
1808 * type, or void, then this method returns an array of length 0.
1809 *
1810 * <p> The elements in the returned array are not sorted and are not in any
1811 * particular order.
1812 *
1813 * @return the array of {@code Field} objects representing the
1814 * public fields
1815 * @throws SecurityException
1816 * If a security manager, <i>s</i>, is present and
1817 * the caller's class loader is not the same as or an
1818 * ancestor of the class loader for the current class and
1819 * invocation of {@link SecurityManager#checkPackageAccess
1820 * s.checkPackageAccess()} denies access to the package
1821 * of this class.
1822 *
1823 * @since 1.1
1824 * @jls 8.2 Class Members
1825 * @jls 8.3 Field Declarations
1826 */
1827 @CallerSensitive
1828 public Field[] getFields() throws SecurityException {
1829 SecurityManager sm = System.getSecurityManager();
1830 if (sm != null) {
1831 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1832 }
1833 return copyFields(privateGetPublicFields());
1834 }
1835
1836
1837 /**
1838 * Returns an array containing {@code Method} objects reflecting all the
1839 * public methods of the class or interface represented by this {@code
1840 * Class} object, including those declared by the class or interface and
1841 * those inherited from superclasses and superinterfaces.
1842 *
1843 * <p> If this {@code Class} object represents an array type, then the
1844 * returned array has a {@code Method} object for each of the public
1845 * methods inherited by the array type from {@code Object}. It does not
1846 * contain a {@code Method} object for {@code clone()}.
1847 *
1848 * <p> If this {@code Class} object represents an interface then the
1849 * returned array does not contain any implicitly declared methods from
1850 * {@code Object}. Therefore, if no methods are explicitly declared in
1851 * this interface or any of its superinterfaces then the returned array
1852 * has length 0. (Note that a {@code Class} object which represents a class
1853 * always has public methods, inherited from {@code Object}.)
1854 *
1855 * <p> The returned array never contains methods with names "{@code <init>}"
1856 * or "{@code <clinit>}".
1857 *
1858 * <p> The elements in the returned array are not sorted and are not in any
1859 * particular order.
1860 *
1861 * <p> Generally, the result is computed as with the following 4 step algorithm.
1862 * Let C be the class or interface represented by this {@code Class} object:
1863 * <ol>
1864 * <li> A union of methods is composed of:
1865 * <ol type="a">
1866 * <li> C's declared public instance and static methods as returned by
1867 * {@link #getDeclaredMethods()} and filtered to include only public
1868 * methods.</li>
1869 * <li> If C is a class other than {@code Object}, then include the result
1870 * of invoking this algorithm recursively on the superclass of C.</li>
1871 * <li> Include the results of invoking this algorithm recursively on all
1872 * direct superinterfaces of C, but include only instance methods.</li>
1873 * </ol></li>
1874 * <li> Union from step 1 is partitioned into subsets of methods with same
1875 * signature (name, parameter types) and return type.</li>
1876 * <li> Within each such subset only the most specific methods are selected.
1877 * Let method M be a method from a set of methods with same signature
1878 * and return type. M is most specific if there is no such method
1879 * N != M from the same set, such that N is more specific than M.
1880 * N is more specific than M if:
1881 * <ol type="a">
1882 * <li> N is declared by a class and M is declared by an interface; or</li>
1883 * <li> N and M are both declared by classes or both by interfaces and
1884 * N's declaring type is the same as or a subtype of M's declaring type
1885 * (clearly, if M's and N's declaring types are the same type, then
1886 * M and N are the same method).</li>
1887 * </ol></li>
1888 * <li> The result of this algorithm is the union of all selected methods from
1889 * step 3.</li>
1890 * </ol>
1891 *
1892 * @apiNote There may be more than one method with a particular name
1893 * and parameter types in a class because while the Java language forbids a
1894 * class to declare multiple methods with the same signature but different
1895 * return types, the Java virtual machine does not. This
1896 * increased flexibility in the virtual machine can be used to
1897 * implement various language features. For example, covariant
1898 * returns can be implemented with {@linkplain
1899 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
1900 * method and the overriding method would have the same
1901 * signature but different return types.
1902 *
1903 * @return the array of {@code Method} objects representing the
1904 * public methods of this class
1905 * @throws SecurityException
1906 * If a security manager, <i>s</i>, is present and
1907 * the caller's class loader is not the same as or an
1908 * ancestor of the class loader for the current class and
1909 * invocation of {@link SecurityManager#checkPackageAccess
1910 * s.checkPackageAccess()} denies access to the package
1911 * of this class.
1912 *
1913 * @jls 8.2 Class Members
1914 * @jls 8.4 Method Declarations
1915 * @since 1.1
1916 */
1917 @CallerSensitive
1918 public Method[] getMethods() throws SecurityException {
1919 SecurityManager sm = System.getSecurityManager();
1920 if (sm != null) {
1921 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1922 }
1923 return copyMethods(privateGetPublicMethods());
1924 }
1925
1926
1927 /**
1928 * Returns an array containing {@code Constructor} objects reflecting
1929 * all the public constructors of the class represented by this
1930 * {@code Class} object. An array of length 0 is returned if the
1931 * class has no public constructors, or if the class is an array class, or
1932 * if the class reflects a primitive type or void.
1933 *
1934 * Note that while this method returns an array of {@code
1935 * Constructor<T>} objects (that is an array of constructors from
1936 * this class), the return type of this method is {@code
1937 * Constructor<?>[]} and <em>not</em> {@code Constructor<T>[]} as
1938 * might be expected. This less informative return type is
1939 * necessary since after being returned from this method, the
1940 * array could be modified to hold {@code Constructor} objects for
1941 * different classes, which would violate the type guarantees of
1942 * {@code Constructor<T>[]}.
1943 *
1944 * @return the array of {@code Constructor} objects representing the
1945 * public constructors of this class
1946 * @throws SecurityException
1947 * If a security manager, <i>s</i>, is present and
1948 * the caller's class loader is not the same as or an
1949 * ancestor of the class loader for the current class and
1950 * invocation of {@link SecurityManager#checkPackageAccess
1951 * s.checkPackageAccess()} denies access to the package
1952 * of this class.
1953 *
1954 * @since 1.1
1955 */
1956 @CallerSensitive
1957 public Constructor<?>[] getConstructors() throws SecurityException {
1958 SecurityManager sm = System.getSecurityManager();
1959 if (sm != null) {
1960 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
1961 }
1962 return copyConstructors(privateGetDeclaredConstructors(true));
1963 }
1964
1965
1966 /**
1967 * Returns a {@code Field} object that reflects the specified public member
1968 * field of the class or interface represented by this {@code Class}
1969 * object. The {@code name} parameter is a {@code String} specifying the
1970 * simple name of the desired field.
1971 *
1972 * <p> The field to be reflected is determined by the algorithm that
1973 * follows. Let C be the class or interface represented by this object:
1974 *
1975 * <OL>
1976 * <LI> If C declares a public field with the name specified, that is the
1977 * field to be reflected.</LI>
1978 * <LI> If no field was found in step 1 above, this algorithm is applied
1979 * recursively to each direct superinterface of C. The direct
1980 * superinterfaces are searched in the order they were declared.</LI>
1981 * <LI> If no field was found in steps 1 and 2 above, and C has a
1982 * superclass S, then this algorithm is invoked recursively upon S.
1983 * If C has no superclass, then a {@code NoSuchFieldException}
1984 * is thrown.</LI>
1985 * </OL>
1986 *
1987 * <p> If this {@code Class} object represents an array type, then this
1988 * method does not find the {@code length} field of the array type.
1989 *
1990 * @param name the field name
1991 * @return the {@code Field} object of this class specified by
1992 * {@code name}
1993 * @throws NoSuchFieldException if a field with the specified name is
1994 * not found.
1995 * @throws NullPointerException if {@code name} is {@code null}
1996 * @throws SecurityException
1997 * If a security manager, <i>s</i>, is present and
1998 * the caller's class loader is not the same as or an
1999 * ancestor of the class loader for the current class and
2000 * invocation of {@link SecurityManager#checkPackageAccess
2001 * s.checkPackageAccess()} denies access to the package
2002 * of this class.
2003 *
2004 * @since 1.1
2005 * @jls 8.2 Class Members
2006 * @jls 8.3 Field Declarations
2007 */
2008 @CallerSensitive
2009 public Field getField(String name)
2010 throws NoSuchFieldException, SecurityException {
2011 Objects.requireNonNull(name);
2012 SecurityManager sm = System.getSecurityManager();
2013 if (sm != null) {
2014 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
2015 }
2016 Field field = getField0(name);
2017 if (field == null) {
2018 throw new NoSuchFieldException(name);
2019 }
2020 return getReflectionFactory().copyField(field);
2021 }
2022
2023
2024 /**
2025 * Returns a {@code Method} object that reflects the specified public
2026 * member method of the class or interface represented by this
2027 * {@code Class} object. The {@code name} parameter is a
2028 * {@code String} specifying the simple name of the desired method. The
2029 * {@code parameterTypes} parameter is an array of {@code Class}
2030 * objects that identify the method's formal parameter types, in declared
2031 * order. If {@code parameterTypes} is {@code null}, it is
2032 * treated as if it were an empty array.
2033 *
2034 * <p> If this {@code Class} object represents an array type, then this
2035 * method finds any public method inherited by the array type from
2036 * {@code Object} except method {@code clone()}.
2037 *
2038 * <p> If this {@code Class} object represents an interface then this
2039 * method does not find any implicitly declared method from
2040 * {@code Object}. Therefore, if no methods are explicitly declared in
2041 * this interface or any of its superinterfaces, then this method does not
2042 * find any method.
2043 *
2044 * <p> This method does not find any method with name "{@code <init>}" or
2045 * "{@code <clinit>}".
2046 *
2047 * <p> Generally, the method to be reflected is determined by the 4 step
2048 * algorithm that follows.
2049 * Let C be the class or interface represented by this {@code Class} object:
2050 * <ol>
2051 * <li> A union of methods is composed of:
2052 * <ol type="a">
2053 * <li> C's declared public instance and static methods as returned by
2054 * {@link #getDeclaredMethods()} and filtered to include only public
2055 * methods that match given {@code name} and {@code parameterTypes}</li>
2056 * <li> If C is a class other than {@code Object}, then include the result
2057 * of invoking this algorithm recursively on the superclass of C.</li>
2058 * <li> Include the results of invoking this algorithm recursively on all
2059 * direct superinterfaces of C, but include only instance methods.</li>
2060 * </ol></li>
2061 * <li> This union is partitioned into subsets of methods with same
2062 * return type (the selection of methods from step 1 also guarantees that
2063 * they have the same method name and parameter types).</li>
2064 * <li> Within each such subset only the most specific methods are selected.
2065 * Let method M be a method from a set of methods with same VM
2066 * signature (return type, name, parameter types).
2067 * M is most specific if there is no such method N != M from the same
2068 * set, such that N is more specific than M. N is more specific than M
2069 * if:
2070 * <ol type="a">
2071 * <li> N is declared by a class and M is declared by an interface; or</li>
2072 * <li> N and M are both declared by classes or both by interfaces and
2073 * N's declaring type is the same as or a subtype of M's declaring type
2074 * (clearly, if M's and N's declaring types are the same type, then
2075 * M and N are the same method).</li>
2076 * </ol></li>
2077 * <li> The result of this algorithm is chosen arbitrarily from the methods
2078 * with most specific return type among all selected methods from step 3.
2079 * Let R be a return type of a method M from the set of all selected methods
2080 * from step 3. M is a method with most specific return type if there is
2081 * no such method N != M from the same set, having return type S != R,
2082 * such that S is a subtype of R as determined by
2083 * R.class.{@link #isAssignableFrom}(S.class).
2084 * </ol>
2085 *
2086 * @apiNote There may be more than one method with matching name and
2087 * parameter types in a class because while the Java language forbids a
2088 * class to declare multiple methods with the same signature but different
2089 * return types, the Java virtual machine does not. This
2090 * increased flexibility in the virtual machine can be used to
2091 * implement various language features. For example, covariant
2092 * returns can be implemented with {@linkplain
2093 * java.lang.reflect.Method#isBridge bridge methods}; the bridge
2094 * method and the overriding method would have the same
2095 * signature but different return types. This method would return the
2096 * overriding method as it would have a more specific return type.
2097 *
2098 * @param name the name of the method
2099 * @param parameterTypes the list of parameters
2100 * @return the {@code Method} object that matches the specified
2101 * {@code name} and {@code parameterTypes}
2102 * @throws NoSuchMethodException if a matching method is not found
2103 * or if the name is "<init>"or "<clinit>".
2104 * @throws NullPointerException if {@code name} is {@code null}
2105 * @throws SecurityException
2106 * If a security manager, <i>s</i>, is present and
2107 * the caller's class loader is not the same as or an
2108 * ancestor of the class loader for the current class and
2109 * invocation of {@link SecurityManager#checkPackageAccess
2110 * s.checkPackageAccess()} denies access to the package
2111 * of this class.
2112 *
2113 * @jls 8.2 Class Members
2114 * @jls 8.4 Method Declarations
2115 * @since 1.1
2116 */
2117 @CallerSensitive
2118 public Method getMethod(String name, Class<?>... parameterTypes)
2119 throws NoSuchMethodException, SecurityException {
2120 Objects.requireNonNull(name);
2121 SecurityManager sm = System.getSecurityManager();
2122 if (sm != null) {
2123 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
2124 }
2125 Method method = getMethod0(name, parameterTypes);
2126 if (method == null) {
2127 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2128 }
2129 return getReflectionFactory().copyMethod(method);
2130 }
2131
2132 /**
2133 * Returns a {@code Constructor} object that reflects the specified
2134 * public constructor of the class represented by this {@code Class}
2135 * object. The {@code parameterTypes} parameter is an array of
2136 * {@code Class} objects that identify the constructor's formal
2137 * parameter types, in declared order.
2138 *
2139 * If this {@code Class} object represents an inner class
2140 * declared in a non-static context, the formal parameter types
2141 * include the explicit enclosing instance as the first parameter.
2142 *
2143 * <p> The constructor to reflect is the public constructor of the class
2144 * represented by this {@code Class} object whose formal parameter
2145 * types match those specified by {@code parameterTypes}.
2146 *
2147 * @param parameterTypes the parameter array
2148 * @return the {@code Constructor} object of the public constructor that
2149 * matches the specified {@code parameterTypes}
2150 * @throws NoSuchMethodException if a matching method is not found.
2151 * @throws SecurityException
2152 * If a security manager, <i>s</i>, is present and
2153 * the caller's class loader is not the same as or an
2154 * ancestor of the class loader for the current class and
2155 * invocation of {@link SecurityManager#checkPackageAccess
2156 * s.checkPackageAccess()} denies access to the package
2157 * of this class.
2158 *
2159 * @since 1.1
2160 */
2161 @CallerSensitive
2162 public Constructor<T> getConstructor(Class<?>... parameterTypes)
2163 throws NoSuchMethodException, SecurityException
2164 {
2165 SecurityManager sm = System.getSecurityManager();
2166 if (sm != null) {
2167 checkMemberAccess(sm, Member.PUBLIC, Reflection.getCallerClass(), true);
2168 }
2169 return getReflectionFactory().copyConstructor(
2170 getConstructor0(parameterTypes, Member.PUBLIC));
2171 }
2172
2173
2174 /**
2175 * Returns an array of {@code Class} objects reflecting all the
2176 * classes and interfaces declared as members of the class represented by
2177 * this {@code Class} object. This includes public, protected, default
2178 * (package) access, and private classes and interfaces declared by the
2179 * class, but excludes inherited classes and interfaces. This method
2180 * returns an array of length 0 if the class declares no classes or
2181 * interfaces as members, or if this {@code Class} object represents a
2182 * primitive type, an array class, or void.
2183 *
2184 * @return the array of {@code Class} objects representing all the
2185 * declared members of this class
2186 * @throws SecurityException
2187 * If a security manager, <i>s</i>, is present and any of the
2188 * following conditions is met:
2189 *
2190 * <ul>
2191 *
2192 * <li> the caller's class loader is not the same as the
2193 * class loader of this class and invocation of
2194 * {@link SecurityManager#checkPermission
2195 * s.checkPermission} method with
2196 * {@code RuntimePermission("accessDeclaredMembers")}
2197 * denies access to the declared classes within this class
2198 *
2199 * <li> the caller's class loader is not the same as or an
2200 * ancestor of the class loader for the current class and
2201 * invocation of {@link SecurityManager#checkPackageAccess
2202 * s.checkPackageAccess()} denies access to the package
2203 * of this class
2204 *
2205 * </ul>
2206 *
2207 * @since 1.1
2208 */
2209 @CallerSensitive
2210 public Class<?>[] getDeclaredClasses() throws SecurityException {
2211 SecurityManager sm = System.getSecurityManager();
2212 if (sm != null) {
2213 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), false);
2214 }
2215 return getDeclaredClasses0();
2216 }
2217
2218
2219 /**
2220 * Returns an array of {@code Field} objects reflecting all the fields
2221 * declared by the class or interface represented by this
2222 * {@code Class} object. This includes public, protected, default
2223 * (package) access, and private fields, but excludes inherited fields.
2224 *
2225 * <p> If this {@code Class} object represents a class or interface with no
2226 * declared fields, then this method returns an array of length 0.
2227 *
2228 * <p> If this {@code Class} object represents an array type, a primitive
2229 * type, or void, then this method returns an array of length 0.
2230 *
2231 * <p> The elements in the returned array are not sorted and are not in any
2232 * particular order.
2233 *
2234 * @return the array of {@code Field} objects representing all the
2235 * declared fields of this class
2236 * @throws SecurityException
2237 * If a security manager, <i>s</i>, is present and any of the
2238 * following conditions is met:
2239 *
2240 * <ul>
2241 *
2242 * <li> the caller's class loader is not the same as the
2243 * class loader of this class and invocation of
2244 * {@link SecurityManager#checkPermission
2245 * s.checkPermission} method with
2246 * {@code RuntimePermission("accessDeclaredMembers")}
2247 * denies access to the declared fields within this class
2248 *
2249 * <li> the caller's class loader is not the same as or an
2250 * ancestor of the class loader for the current class and
2251 * invocation of {@link SecurityManager#checkPackageAccess
2252 * s.checkPackageAccess()} denies access to the package
2253 * of this class
2254 *
2255 * </ul>
2256 *
2257 * @since 1.1
2258 * @jls 8.2 Class Members
2259 * @jls 8.3 Field Declarations
2260 */
2261 @CallerSensitive
2262 public Field[] getDeclaredFields() throws SecurityException {
2263 SecurityManager sm = System.getSecurityManager();
2264 if (sm != null) {
2265 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2266 }
2267 return copyFields(privateGetDeclaredFields(false));
2268 }
2269
2270
2271 /**
2272 * Returns an array containing {@code Method} objects reflecting all the
2273 * declared methods of the class or interface represented by this {@code
2274 * Class} object, including public, protected, default (package)
2275 * access, and private methods, but excluding inherited methods.
2276 *
2277 * <p> If this {@code Class} object represents a type that has multiple
2278 * declared methods with the same name and parameter types, but different
2279 * return types, then the returned array has a {@code Method} object for
2280 * each such method.
2281 *
2282 * <p> If this {@code Class} object represents a type that has a class
2283 * initialization method {@code <clinit>}, then the returned array does
2284 * <em>not</em> have a corresponding {@code Method} object.
2285 *
2286 * <p> If this {@code Class} object represents a class or interface with no
2287 * declared methods, then the returned array has length 0.
2288 *
2289 * <p> If this {@code Class} object represents an array type, a primitive
2290 * type, or void, then the returned array has length 0.
2291 *
2292 * <p> The elements in the returned array are not sorted and are not in any
2293 * particular order.
2294 *
2295 * @return the array of {@code Method} objects representing all the
2296 * declared methods of this class
2297 * @throws SecurityException
2298 * If a security manager, <i>s</i>, is present and any of the
2299 * following conditions is met:
2300 *
2301 * <ul>
2302 *
2303 * <li> the caller's class loader is not the same as the
2304 * class loader of this class and invocation of
2305 * {@link SecurityManager#checkPermission
2306 * s.checkPermission} method with
2307 * {@code RuntimePermission("accessDeclaredMembers")}
2308 * denies access to the declared methods within this class
2309 *
2310 * <li> the caller's class loader is not the same as or an
2311 * ancestor of the class loader for the current class and
2312 * invocation of {@link SecurityManager#checkPackageAccess
2313 * s.checkPackageAccess()} denies access to the package
2314 * of this class
2315 *
2316 * </ul>
2317 *
2318 * @jls 8.2 Class Members
2319 * @jls 8.4 Method Declarations
2320 * @since 1.1
2321 */
2322 @CallerSensitive
2323 public Method[] getDeclaredMethods() throws SecurityException {
2324 SecurityManager sm = System.getSecurityManager();
2325 if (sm != null) {
2326 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2327 }
2328 return copyMethods(privateGetDeclaredMethods(false));
2329 }
2330
2331
2332 /**
2333 * Returns an array of {@code Constructor} objects reflecting all the
2334 * constructors declared by the class represented by this
2335 * {@code Class} object. These are public, protected, default
2336 * (package) access, and private constructors. The elements in the array
2337 * returned are not sorted and are not in any particular order. If the
2338 * class has a default constructor, it is included in the returned array.
2339 * This method returns an array of length 0 if this {@code Class}
2340 * object represents an interface, a primitive type, an array class, or
2341 * void.
2342 *
2343 * <p> See <em>The Java Language Specification</em>, section 8.2.
2344 *
2345 * @return the array of {@code Constructor} objects representing all the
2346 * declared constructors of this class
2347 * @throws SecurityException
2348 * If a security manager, <i>s</i>, is present and any of the
2349 * following conditions is met:
2350 *
2351 * <ul>
2352 *
2353 * <li> the caller's class loader is not the same as the
2354 * class loader of this class and invocation of
2355 * {@link SecurityManager#checkPermission
2356 * s.checkPermission} method with
2357 * {@code RuntimePermission("accessDeclaredMembers")}
2358 * denies access to the declared constructors within this class
2359 *
2360 * <li> the caller's class loader is not the same as or an
2361 * ancestor of the class loader for the current class and
2362 * invocation of {@link SecurityManager#checkPackageAccess
2363 * s.checkPackageAccess()} denies access to the package
2364 * of this class
2365 *
2366 * </ul>
2367 *
2368 * @since 1.1
2369 */
2370 @CallerSensitive
2371 public Constructor<?>[] getDeclaredConstructors() throws SecurityException {
2372 SecurityManager sm = System.getSecurityManager();
2373 if (sm != null) {
2374 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2375 }
2376 return copyConstructors(privateGetDeclaredConstructors(false));
2377 }
2378
2379
2380 /**
2381 * Returns a {@code Field} object that reflects the specified declared
2382 * field of the class or interface represented by this {@code Class}
2383 * object. The {@code name} parameter is a {@code String} that specifies
2384 * the simple name of the desired field.
2385 *
2386 * <p> If this {@code Class} object represents an array type, then this
2387 * method does not find the {@code length} field of the array type.
2388 *
2389 * @param name the name of the field
2390 * @return the {@code Field} object for the specified field in this
2391 * class
2392 * @throws NoSuchFieldException if a field with the specified name is
2393 * not found.
2394 * @throws NullPointerException if {@code name} is {@code null}
2395 * @throws SecurityException
2396 * If a security manager, <i>s</i>, is present and any of the
2397 * following conditions is met:
2398 *
2399 * <ul>
2400 *
2401 * <li> the caller's class loader is not the same as the
2402 * class loader of this class and invocation of
2403 * {@link SecurityManager#checkPermission
2404 * s.checkPermission} method with
2405 * {@code RuntimePermission("accessDeclaredMembers")}
2406 * denies access to the declared field
2407 *
2408 * <li> the caller's class loader is not the same as or an
2409 * ancestor of the class loader for the current class and
2410 * invocation of {@link SecurityManager#checkPackageAccess
2411 * s.checkPackageAccess()} denies access to the package
2412 * of this class
2413 *
2414 * </ul>
2415 *
2416 * @since 1.1
2417 * @jls 8.2 Class Members
2418 * @jls 8.3 Field Declarations
2419 */
2420 @CallerSensitive
2421 public Field getDeclaredField(String name)
2422 throws NoSuchFieldException, SecurityException {
2423 Objects.requireNonNull(name);
2424 SecurityManager sm = System.getSecurityManager();
2425 if (sm != null) {
2426 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2427 }
2428 Field field = searchFields(privateGetDeclaredFields(false), name);
2429 if (field == null) {
2430 throw new NoSuchFieldException(name);
2431 }
2432 return getReflectionFactory().copyField(field);
2433 }
2434
2435
2436 /**
2437 * Returns a {@code Method} object that reflects the specified
2438 * declared method of the class or interface represented by this
2439 * {@code Class} object. The {@code name} parameter is a
2440 * {@code String} that specifies the simple name of the desired
2441 * method, and the {@code parameterTypes} parameter is an array of
2442 * {@code Class} objects that identify the method's formal parameter
2443 * types, in declared order. If more than one method with the same
2444 * parameter types is declared in a class, and one of these methods has a
2445 * return type that is more specific than any of the others, that method is
2446 * returned; otherwise one of the methods is chosen arbitrarily. If the
2447 * name is "<init>"or "<clinit>" a {@code NoSuchMethodException}
2448 * is raised.
2449 *
2450 * <p> If this {@code Class} object represents an array type, then this
2451 * method does not find the {@code clone()} method.
2452 *
2453 * @param name the name of the method
2454 * @param parameterTypes the parameter array
2455 * @return the {@code Method} object for the method of this class
2456 * matching the specified name and parameters
2457 * @throws NoSuchMethodException if a matching method is not found.
2458 * @throws NullPointerException if {@code name} is {@code null}
2459 * @throws SecurityException
2460 * If a security manager, <i>s</i>, is present and any of the
2461 * following conditions is met:
2462 *
2463 * <ul>
2464 *
2465 * <li> the caller's class loader is not the same as the
2466 * class loader of this class and invocation of
2467 * {@link SecurityManager#checkPermission
2468 * s.checkPermission} method with
2469 * {@code RuntimePermission("accessDeclaredMembers")}
2470 * denies access to the declared method
2471 *
2472 * <li> the caller's class loader is not the same as or an
2473 * ancestor of the class loader for the current class and
2474 * invocation of {@link SecurityManager#checkPackageAccess
2475 * s.checkPackageAccess()} denies access to the package
2476 * of this class
2477 *
2478 * </ul>
2479 *
2480 * @jls 8.2 Class Members
2481 * @jls 8.4 Method Declarations
2482 * @since 1.1
2483 */
2484 @CallerSensitive
2485 public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
2486 throws NoSuchMethodException, SecurityException {
2487 Objects.requireNonNull(name);
2488 SecurityManager sm = System.getSecurityManager();
2489 if (sm != null) {
2490 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2491 }
2492 Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
2493 if (method == null) {
2494 throw new NoSuchMethodException(methodToString(name, parameterTypes));
2495 }
2496 return getReflectionFactory().copyMethod(method);
2497 }
2498
2499 /**
2500 * Returns the list of {@code Method} objects for the declared public
2501 * methods of this class or interface that have the specified method name
2502 * and parameter types.
2503 *
2504 * @param name the name of the method
2505 * @param parameterTypes the parameter array
2506 * @return the list of {@code Method} objects for the public methods of
2507 * this class matching the specified name and parameters
2508 */
2509 List<Method> getDeclaredPublicMethods(String name, Class<?>... parameterTypes) {
2510 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
2511 ReflectionFactory factory = getReflectionFactory();
2512 List<Method> result = new ArrayList<>();
2513 for (Method method : methods) {
2514 if (method.getName().equals(name)
2515 && Arrays.equals(
2516 factory.getExecutableSharedParameterTypes(method),
2517 parameterTypes)) {
2518 result.add(factory.copyMethod(method));
2519 }
2520 }
2521 return result;
2522 }
2523
2524 /**
2525 * Returns a {@code Constructor} object that reflects the specified
2526 * constructor of the class or interface represented by this
2527 * {@code Class} object. The {@code parameterTypes} parameter is
2528 * an array of {@code Class} objects that identify the constructor's
2529 * formal parameter types, in declared order.
2530 *
2531 * If this {@code Class} object represents an inner class
2532 * declared in a non-static context, the formal parameter types
2533 * include the explicit enclosing instance as the first parameter.
2534 *
2535 * @param parameterTypes the parameter array
2536 * @return The {@code Constructor} object for the constructor with the
2537 * specified parameter list
2538 * @throws NoSuchMethodException if a matching method is not found.
2539 * @throws SecurityException
2540 * If a security manager, <i>s</i>, is present and any of the
2541 * following conditions is met:
2542 *
2543 * <ul>
2544 *
2545 * <li> the caller's class loader is not the same as the
2546 * class loader of this class and invocation of
2547 * {@link SecurityManager#checkPermission
2548 * s.checkPermission} method with
2549 * {@code RuntimePermission("accessDeclaredMembers")}
2550 * denies access to the declared constructor
2551 *
2552 * <li> the caller's class loader is not the same as or an
2553 * ancestor of the class loader for the current class and
2554 * invocation of {@link SecurityManager#checkPackageAccess
2555 * s.checkPackageAccess()} denies access to the package
2556 * of this class
2557 *
2558 * </ul>
2559 *
2560 * @since 1.1
2561 */
2562 @CallerSensitive
2563 public Constructor<T> getDeclaredConstructor(Class<?>... parameterTypes)
2564 throws NoSuchMethodException, SecurityException
2565 {
2566 SecurityManager sm = System.getSecurityManager();
2567 if (sm != null) {
2568 checkMemberAccess(sm, Member.DECLARED, Reflection.getCallerClass(), true);
2569 }
2570
2571 return getReflectionFactory().copyConstructor(
2572 getConstructor0(parameterTypes, Member.DECLARED));
2573 }
2574
2575 /**
2576 * Finds a resource with a given name.
2577 *
2578 * <p> If this class is in a named {@link Module Module} then this method
2579 * will attempt to find the resource in the module. This is done by
2580 * delegating to the module's class loader {@link
2581 * ClassLoader#findResource(String,String) findResource(String,String)}
2582 * method, invoking it with the module name and the absolute name of the
2583 * resource. Resources in named modules are subject to the rules for
2584 * encapsulation specified in the {@code Module} {@link
2585 * Module#getResourceAsStream getResourceAsStream} method and so this
2586 * method returns {@code null} when the resource is a
2587 * non-"{@code .class}" resource in a package that is not open to the
2588 * caller's module.
2589 *
2590 * <p> Otherwise, if this class is not in a named module then the rules for
2591 * searching resources associated with a given class are implemented by the
2592 * defining {@linkplain ClassLoader class loader} of the class. This method
2593 * delegates to this object's class loader. If this object was loaded by
2594 * the bootstrap class loader, the method delegates to {@link
2595 * ClassLoader#getSystemResourceAsStream}.
2596 *
2597 * <p> Before delegation, an absolute resource name is constructed from the
2598 * given resource name using this algorithm:
2599 *
2600 * <ul>
2601 *
2602 * <li> If the {@code name} begins with a {@code '/'}
2603 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2604 * portion of the {@code name} following the {@code '/'}.
2605 *
2606 * <li> Otherwise, the absolute name is of the following form:
2607 *
2608 * <blockquote>
2609 * {@code modified_package_name/name}
2610 * </blockquote>
2611 *
2612 * <p> Where the {@code modified_package_name} is the package name of this
2613 * object with {@code '/'} substituted for {@code '.'}
2614 * (<code>'\u002e'</code>).
2615 *
2616 * </ul>
2617 *
2618 * @param name name of the desired resource
2619 * @return A {@link java.io.InputStream} object; {@code null} if no
2620 * resource with this name is found, the resource is in a package
2621 * that is not {@linkplain Module#isOpen(String, Module) open} to at
2622 * least the caller module, or access to the resource is denied
2623 * by the security manager.
2624 * @throws NullPointerException If {@code name} is {@code null}
2625 *
2626 * @see Module#getResourceAsStream(String)
2627 * @since 1.1
2628 * @revised 9
2629 * @spec JPMS
2630 */
2631 @CallerSensitive
2632 public InputStream getResourceAsStream(String name) {
2633 name = resolveName(name);
2634
2635 Module thisModule = getModule();
2636 if (thisModule.isNamed()) {
2637 // check if resource can be located by caller
2638 if (Resources.canEncapsulate(name)
2639 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2640 return null;
2641 }
2642
2643 // resource not encapsulated or in package open to caller
2644 String mn = thisModule.getName();
2645 ClassLoader cl = getClassLoader0();
2646 try {
2647
2648 // special-case built-in class loaders to avoid the
2649 // need for a URL connection
2650 if (cl == null) {
2651 return BootLoader.findResourceAsStream(mn, name);
2652 } else if (cl instanceof BuiltinClassLoader) {
2653 return ((BuiltinClassLoader) cl).findResourceAsStream(mn, name);
2654 } else {
2655 URL url = cl.findResource(mn, name);
2656 return (url != null) ? url.openStream() : null;
2657 }
2658
2659 } catch (IOException | SecurityException e) {
2660 return null;
2661 }
2662 }
2663
2664 // unnamed module
2665 ClassLoader cl = getClassLoader0();
2666 if (cl == null) {
2667 return ClassLoader.getSystemResourceAsStream(name);
2668 } else {
2669 return cl.getResourceAsStream(name);
2670 }
2671 }
2672
2673 /**
2674 * Finds a resource with a given name.
2675 *
2676 * <p> If this class is in a named {@link Module Module} then this method
2677 * will attempt to find the resource in the module. This is done by
2678 * delegating to the module's class loader {@link
2679 * ClassLoader#findResource(String,String) findResource(String,String)}
2680 * method, invoking it with the module name and the absolute name of the
2681 * resource. Resources in named modules are subject to the rules for
2682 * encapsulation specified in the {@code Module} {@link
2683 * Module#getResourceAsStream getResourceAsStream} method and so this
2684 * method returns {@code null} when the resource is a
2685 * non-"{@code .class}" resource in a package that is not open to the
2686 * caller's module.
2687 *
2688 * <p> Otherwise, if this class is not in a named module then the rules for
2689 * searching resources associated with a given class are implemented by the
2690 * defining {@linkplain ClassLoader class loader} of the class. This method
2691 * delegates to this object's class loader. If this object was loaded by
2692 * the bootstrap class loader, the method delegates to {@link
2693 * ClassLoader#getSystemResource}.
2694 *
2695 * <p> Before delegation, an absolute resource name is constructed from the
2696 * given resource name using this algorithm:
2697 *
2698 * <ul>
2699 *
2700 * <li> If the {@code name} begins with a {@code '/'}
2701 * (<code>'\u002f'</code>), then the absolute name of the resource is the
2702 * portion of the {@code name} following the {@code '/'}.
2703 *
2704 * <li> Otherwise, the absolute name is of the following form:
2705 *
2706 * <blockquote>
2707 * {@code modified_package_name/name}
2708 * </blockquote>
2709 *
2710 * <p> Where the {@code modified_package_name} is the package name of this
2711 * object with {@code '/'} substituted for {@code '.'}
2712 * (<code>'\u002e'</code>).
2713 *
2714 * </ul>
2715 *
2716 * @param name name of the desired resource
2717 * @return A {@link java.net.URL} object; {@code null} if no resource with
2718 * this name is found, the resource cannot be located by a URL, the
2719 * resource is in a package that is not
2720 * {@linkplain Module#isOpen(String, Module) open} to at least the caller
2721 * module, or access to the resource is denied by the security
2722 * manager.
2723 * @throws NullPointerException If {@code name} is {@code null}
2724 * @since 1.1
2725 * @revised 9
2726 * @spec JPMS
2727 */
2728 @CallerSensitive
2729 public URL getResource(String name) {
2730 name = resolveName(name);
2731
2732 Module thisModule = getModule();
2733 if (thisModule.isNamed()) {
2734 // check if resource can be located by caller
2735 if (Resources.canEncapsulate(name)
2736 && !isOpenToCaller(name, Reflection.getCallerClass())) {
2737 return null;
2738 }
2739
2740 // resource not encapsulated or in package open to caller
2741 String mn = thisModule.getName();
2742 ClassLoader cl = getClassLoader0();
2743 try {
2744 if (cl == null) {
2745 return BootLoader.findResource(mn, name);
2746 } else {
2747 return cl.findResource(mn, name);
2748 }
2749 } catch (IOException ioe) {
2750 return null;
2751 }
2752 }
2753
2754 // unnamed module
2755 ClassLoader cl = getClassLoader0();
2756 if (cl == null) {
2757 return ClassLoader.getSystemResource(name);
2758 } else {
2759 return cl.getResource(name);
2760 }
2761 }
2762
2763 /**
2764 * Returns true if a resource with the given name can be located by the
2765 * given caller. All resources in a module can be located by code in
2766 * the module. For other callers, then the package needs to be open to
2767 * the caller.
2768 */
2769 private boolean isOpenToCaller(String name, Class<?> caller) {
2770 // assert getModule().isNamed();
2771 Module thisModule = getModule();
2772 Module callerModule = (caller != null) ? caller.getModule() : null;
2773 if (callerModule != thisModule) {
2774 String pn = Resources.toPackageName(name);
2775 if (thisModule.getDescriptor().packages().contains(pn)) {
2776 if (callerModule == null && !thisModule.isOpen(pn)) {
2777 // no caller, package not open
2778 return false;
2779 }
2780 if (!thisModule.isOpen(pn, callerModule)) {
2781 // package not open to caller
2782 return false;
2783 }
2784 }
2785 }
2786 return true;
2787 }
2788
2789
2790 /** protection domain returned when the internal domain is null */
2791 private static java.security.ProtectionDomain allPermDomain;
2792
2793 /**
2794 * Returns the {@code ProtectionDomain} of this class. If there is a
2795 * security manager installed, this method first calls the security
2796 * manager's {@code checkPermission} method with a
2797 * {@code RuntimePermission("getProtectionDomain")} permission to
2798 * ensure it's ok to get the
2799 * {@code ProtectionDomain}.
2800 *
2801 * @return the ProtectionDomain of this class
2802 *
2803 * @throws SecurityException
2804 * if a security manager exists and its
2805 * {@code checkPermission} method doesn't allow
2806 * getting the ProtectionDomain.
2807 *
2808 * @see java.security.ProtectionDomain
2809 * @see SecurityManager#checkPermission
2810 * @see java.lang.RuntimePermission
2811 * @since 1.2
2812 */
2813 public java.security.ProtectionDomain getProtectionDomain() {
2814 SecurityManager sm = System.getSecurityManager();
2815 if (sm != null) {
2816 sm.checkPermission(SecurityConstants.GET_PD_PERMISSION);
2817 }
2818 java.security.ProtectionDomain pd = getProtectionDomain0();
2819 if (pd == null) {
2820 if (allPermDomain == null) {
2821 java.security.Permissions perms =
2822 new java.security.Permissions();
2823 perms.add(SecurityConstants.ALL_PERMISSION);
2824 allPermDomain =
2825 new java.security.ProtectionDomain(null, perms);
2826 }
2827 pd = allPermDomain;
2828 }
2829 return pd;
2830 }
2831
2832
2833 /**
2834 * Returns the ProtectionDomain of this class.
2835 */
2836 private native java.security.ProtectionDomain getProtectionDomain0();
2837
2838 /*
2839 * Return the Virtual Machine's Class object for the named
2840 * primitive type.
2841 */
2842 static native Class<?> getPrimitiveClass(String name);
2843
2844 /*
2845 * Check if client is allowed to access members. If access is denied,
2846 * throw a SecurityException.
2847 *
2848 * This method also enforces package access.
2849 *
2850 * <p> Default policy: allow all clients access with normal Java access
2851 * control.
2852 *
2853 * <p> NOTE: should only be called if a SecurityManager is installed
2854 */
2855 private void checkMemberAccess(SecurityManager sm, int which,
2856 Class<?> caller, boolean checkProxyInterfaces) {
2857 /* Default policy allows access to all {@link Member#PUBLIC} members,
2858 * as well as access to classes that have the same class loader as the caller.
2859 * In all other cases, it requires RuntimePermission("accessDeclaredMembers")
2860 * permission.
2861 */
2862 final ClassLoader ccl = ClassLoader.getClassLoader(caller);
2863 if (which != Member.PUBLIC) {
2864 final ClassLoader cl = getClassLoader0();
2865 if (ccl != cl) {
2866 sm.checkPermission(SecurityConstants.CHECK_MEMBER_ACCESS_PERMISSION);
2867 }
2868 }
2869 this.checkPackageAccess(sm, ccl, checkProxyInterfaces);
2870 }
2871
2872 /*
2873 * Checks if a client loaded in ClassLoader ccl is allowed to access this
2874 * class under the current package access policy. If access is denied,
2875 * throw a SecurityException.
2876 *
2877 * NOTE: this method should only be called if a SecurityManager is active
2878 */
2879 private void checkPackageAccess(SecurityManager sm, final ClassLoader ccl,
2880 boolean checkProxyInterfaces) {
2881 final ClassLoader cl = getClassLoader0();
2882
2883 if (ReflectUtil.needsPackageAccessCheck(ccl, cl)) {
2884 String pkg = this.getPackageName();
2885 if (pkg != null && !pkg.isEmpty()) {
2886 // skip the package access check on a proxy class in default proxy package
2887 if (!Proxy.isProxyClass(this) || ReflectUtil.isNonPublicProxyClass(this)) {
2888 sm.checkPackageAccess(pkg);
2889 }
2890 }
2891 }
2892 // check package access on the proxy interfaces
2893 if (checkProxyInterfaces && Proxy.isProxyClass(this)) {
2894 ReflectUtil.checkProxyPackageAccess(ccl, this.getInterfaces());
2895 }
2896 }
2897
2898 /**
2899 * Add a package name prefix if the name is not absolute Remove leading "/"
2900 * if name is absolute
2901 */
2902 private String resolveName(String name) {
2903 if (!name.startsWith("/")) {
2904 Class<?> c = this;
2905 while (c.isArray()) {
2906 c = c.getComponentType();
2907 }
2908 String baseName = c.getPackageName();
2909 if (baseName != null && !baseName.isEmpty()) {
2910 name = baseName.replace('.', '/') + "/" + name;
2911 }
2912 } else {
2913 name = name.substring(1);
2914 }
2915 return name;
2916 }
2917
2918 /**
2919 * Atomic operations support.
2920 */
2921 private static class Atomic {
2922 // initialize Unsafe machinery here, since we need to call Class.class instance method
2923 // and have to avoid calling it in the static initializer of the Class class...
2924 private static final Unsafe unsafe = Unsafe.getUnsafe();
2925 // offset of Class.reflectionData instance field
2926 private static final long reflectionDataOffset
2927 = unsafe.objectFieldOffset(Class.class, "reflectionData");
2928 // offset of Class.annotationType instance field
2929 private static final long annotationTypeOffset
2930 = unsafe.objectFieldOffset(Class.class, "annotationType");
2931 // offset of Class.annotationData instance field
2932 private static final long annotationDataOffset
2933 = unsafe.objectFieldOffset(Class.class, "annotationData");
2934
2935 static <T> boolean casReflectionData(Class<?> clazz,
2936 SoftReference<ReflectionData<T>> oldData,
2937 SoftReference<ReflectionData<T>> newData) {
2938 return unsafe.compareAndSetReference(clazz, reflectionDataOffset, oldData, newData);
2939 }
2940
2941 static <T> boolean casAnnotationType(Class<?> clazz,
2942 AnnotationType oldType,
2943 AnnotationType newType) {
2944 return unsafe.compareAndSetReference(clazz, annotationTypeOffset, oldType, newType);
2945 }
2946
2947 static <T> boolean casAnnotationData(Class<?> clazz,
2948 AnnotationData oldData,
2949 AnnotationData newData) {
2950 return unsafe.compareAndSetReference(clazz, annotationDataOffset, oldData, newData);
2951 }
2952 }
2953
2954 /**
2955 * Reflection support.
2956 */
2957
2958 // Reflection data caches various derived names and reflective members. Cached
2959 // values may be invalidated when JVM TI RedefineClasses() is called
2960 private static class ReflectionData<T> {
2961 volatile Field[] declaredFields;
2962 volatile Field[] publicFields;
2963 volatile Method[] declaredMethods;
2964 volatile Method[] publicMethods;
2965 volatile Constructor<T>[] declaredConstructors;
2966 volatile Constructor<T>[] publicConstructors;
2967 // Intermediate results for getFields and getMethods
2968 volatile Field[] declaredPublicFields;
2969 volatile Method[] declaredPublicMethods;
2970 volatile Class<?>[] interfaces;
2971
2972 // Cached names
2973 String simpleName;
2974 String canonicalName;
2975 static final String NULL_SENTINEL = new String();
2976
2977 // Value of classRedefinedCount when we created this ReflectionData instance
2978 final int redefinedCount;
2979
2980 ReflectionData(int redefinedCount) {
2981 this.redefinedCount = redefinedCount;
2982 }
2983 }
2984
2985 private transient volatile SoftReference<ReflectionData<T>> reflectionData;
2986
2987 // Incremented by the VM on each call to JVM TI RedefineClasses()
2988 // that redefines this class or a superclass.
2989 private transient volatile int classRedefinedCount;
2990
2991 // Lazily create and cache ReflectionData
2992 private ReflectionData<T> reflectionData() {
2993 SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
2994 int classRedefinedCount = this.classRedefinedCount;
2995 ReflectionData<T> rd;
2996 if (reflectionData != null &&
2997 (rd = reflectionData.get()) != null &&
2998 rd.redefinedCount == classRedefinedCount) {
2999 return rd;
3000 }
3001 // else no SoftReference or cleared SoftReference or stale ReflectionData
3002 // -> create and replace new instance
3003 return newReflectionData(reflectionData, classRedefinedCount);
3004 }
3005
3006 private ReflectionData<T> newReflectionData(SoftReference<ReflectionData<T>> oldReflectionData,
3007 int classRedefinedCount) {
3008 while (true) {
3009 ReflectionData<T> rd = new ReflectionData<>(classRedefinedCount);
3010 // try to CAS it...
3011 if (Atomic.casReflectionData(this, oldReflectionData, new SoftReference<>(rd))) {
3012 return rd;
3013 }
3014 // else retry
3015 oldReflectionData = this.reflectionData;
3016 classRedefinedCount = this.classRedefinedCount;
3017 if (oldReflectionData != null &&
3018 (rd = oldReflectionData.get()) != null &&
3019 rd.redefinedCount == classRedefinedCount) {
3020 return rd;
3021 }
3022 }
3023 }
3024
3025 // Generic signature handling
3026 private native String getGenericSignature0();
3027
3028 // Generic info repository; lazily initialized
3029 private transient volatile ClassRepository genericInfo;
3030
3031 // accessor for factory
3032 private GenericsFactory getFactory() {
3033 // create scope and factory
3034 return CoreReflectionFactory.make(this, ClassScope.make(this));
3035 }
3036
3037 // accessor for generic info repository;
3038 // generic info is lazily initialized
3039 private ClassRepository getGenericInfo() {
3040 ClassRepository genericInfo = this.genericInfo;
3041 if (genericInfo == null) {
3042 String signature = getGenericSignature0();
3043 if (signature == null) {
3044 genericInfo = ClassRepository.NONE;
3045 } else {
3046 genericInfo = ClassRepository.make(signature, getFactory());
3047 }
3048 this.genericInfo = genericInfo;
3049 }
3050 return (genericInfo != ClassRepository.NONE) ? genericInfo : null;
3051 }
3052
3053 // Annotations handling
3054 native byte[] getRawAnnotations();
3055 // Since 1.8
3056 native byte[] getRawTypeAnnotations();
3057 static byte[] getExecutableTypeAnnotationBytes(Executable ex) {
3058 return getReflectionFactory().getExecutableTypeAnnotationBytes(ex);
3059 }
3060
3061 native ConstantPool getConstantPool();
3062
3063 //
3064 //
3065 // java.lang.reflect.Field handling
3066 //
3067 //
3068
3069 // Returns an array of "root" fields. These Field objects must NOT
3070 // be propagated to the outside world, but must instead be copied
3071 // via ReflectionFactory.copyField.
3072 private Field[] privateGetDeclaredFields(boolean publicOnly) {
3073 Field[] res;
3074 ReflectionData<T> rd = reflectionData();
3075 if (rd != null) {
3076 res = publicOnly ? rd.declaredPublicFields : rd.declaredFields;
3077 if (res != null) return res;
3078 }
3079 // No cached value available; request value from VM
3080 res = Reflection.filterFields(this, getDeclaredFields0(publicOnly));
3081 if (rd != null) {
3082 if (publicOnly) {
3083 rd.declaredPublicFields = res;
3084 } else {
3085 rd.declaredFields = res;
3086 }
3087 }
3088 return res;
3089 }
3090
3091 // Returns an array of "root" fields. These Field objects must NOT
3092 // be propagated to the outside world, but must instead be copied
3093 // via ReflectionFactory.copyField.
3094 private Field[] privateGetPublicFields() {
3095 Field[] res;
3096 ReflectionData<T> rd = reflectionData();
3097 if (rd != null) {
3098 res = rd.publicFields;
3099 if (res != null) return res;
3100 }
3101
3102 // Use a linked hash set to ensure order is preserved and
3103 // fields from common super interfaces are not duplicated
3104 LinkedHashSet<Field> fields = new LinkedHashSet<>();
3105
3106 // Local fields
3107 addAll(fields, privateGetDeclaredFields(true));
3108
3109 // Direct superinterfaces, recursively
3110 for (Class<?> si : getInterfaces()) {
3111 addAll(fields, si.privateGetPublicFields());
3112 }
3113
3114 // Direct superclass, recursively
3115 Class<?> sc = getSuperclass();
3116 if (sc != null) {
3117 addAll(fields, sc.privateGetPublicFields());
3118 }
3119
3120 res = fields.toArray(new Field[0]);
3121 if (rd != null) {
3122 rd.publicFields = res;
3123 }
3124 return res;
3125 }
3126
3127 private static void addAll(Collection<Field> c, Field[] o) {
3128 for (Field f : o) {
3129 c.add(f);
3130 }
3131 }
3132
3133
3134 //
3135 //
3136 // java.lang.reflect.Constructor handling
3137 //
3138 //
3139
3140 // Returns an array of "root" constructors. These Constructor
3141 // objects must NOT be propagated to the outside world, but must
3142 // instead be copied via ReflectionFactory.copyConstructor.
3143 private Constructor<T>[] privateGetDeclaredConstructors(boolean publicOnly) {
3144 Constructor<T>[] res;
3145 ReflectionData<T> rd = reflectionData();
3146 if (rd != null) {
3147 res = publicOnly ? rd.publicConstructors : rd.declaredConstructors;
3148 if (res != null) return res;
3149 }
3150 // No cached value available; request value from VM
3151 if (isInterface()) {
3152 @SuppressWarnings("unchecked")
3153 Constructor<T>[] temporaryRes = (Constructor<T>[]) new Constructor<?>[0];
3154 res = temporaryRes;
3155 } else {
3156 res = getDeclaredConstructors0(publicOnly);
3157 }
3158 if (rd != null) {
3159 if (publicOnly) {
3160 rd.publicConstructors = res;
3161 } else {
3162 rd.declaredConstructors = res;
3163 }
3164 }
3165 return res;
3166 }
3167
3168 //
3169 //
3170 // java.lang.reflect.Method handling
3171 //
3172 //
3173
3174 // Returns an array of "root" methods. These Method objects must NOT
3175 // be propagated to the outside world, but must instead be copied
3176 // via ReflectionFactory.copyMethod.
3177 private Method[] privateGetDeclaredMethods(boolean publicOnly) {
3178 Method[] res;
3179 ReflectionData<T> rd = reflectionData();
3180 if (rd != null) {
3181 res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
3182 if (res != null) return res;
3183 }
3184 // No cached value available; request value from VM
3185 res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
3186 if (rd != null) {
3187 if (publicOnly) {
3188 rd.declaredPublicMethods = res;
3189 } else {
3190 rd.declaredMethods = res;
3191 }
3192 }
3193 return res;
3194 }
3195
3196 // Returns an array of "root" methods. These Method objects must NOT
3197 // be propagated to the outside world, but must instead be copied
3198 // via ReflectionFactory.copyMethod.
3199 private Method[] privateGetPublicMethods() {
3200 Method[] res;
3201 ReflectionData<T> rd = reflectionData();
3202 if (rd != null) {
3203 res = rd.publicMethods;
3204 if (res != null) return res;
3205 }
3206
3207 // No cached value available; compute value recursively.
3208 // Start by fetching public declared methods...
3209 PublicMethods pms = new PublicMethods();
3210 for (Method m : privateGetDeclaredMethods(/* publicOnly */ true)) {
3211 pms.merge(m);
3212 }
3213 // ...then recur over superclass methods...
3214 Class<?> sc = getSuperclass();
3215 if (sc != null) {
3216 for (Method m : sc.privateGetPublicMethods()) {
3217 pms.merge(m);
3218 }
3219 }
3220 // ...and finally over direct superinterfaces.
3221 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3222 for (Method m : intf.privateGetPublicMethods()) {
3223 // static interface methods are not inherited
3224 if (!Modifier.isStatic(m.getModifiers())) {
3225 pms.merge(m);
3226 }
3227 }
3228 }
3229
3230 res = pms.toArray();
3231 if (rd != null) {
3232 rd.publicMethods = res;
3233 }
3234 return res;
3235 }
3236
3237
3238 //
3239 // Helpers for fetchers of one field, method, or constructor
3240 //
3241
3242 // This method does not copy the returned Field object!
3243 private static Field searchFields(Field[] fields, String name) {
3244 for (Field field : fields) {
3245 if (field.getName().equals(name)) {
3246 return field;
3247 }
3248 }
3249 return null;
3250 }
3251
3252 // Returns a "root" Field object. This Field object must NOT
3253 // be propagated to the outside world, but must instead be copied
3254 // via ReflectionFactory.copyField.
3255 private Field getField0(String name) {
3256 // Note: the intent is that the search algorithm this routine
3257 // uses be equivalent to the ordering imposed by
3258 // privateGetPublicFields(). It fetches only the declared
3259 // public fields for each class, however, to reduce the number
3260 // of Field objects which have to be created for the common
3261 // case where the field being requested is declared in the
3262 // class which is being queried.
3263 Field res;
3264 // Search declared public fields
3265 if ((res = searchFields(privateGetDeclaredFields(true), name)) != null) {
3266 return res;
3267 }
3268 // Direct superinterfaces, recursively
3269 Class<?>[] interfaces = getInterfaces(/* cloneArray */ false);
3270 for (Class<?> c : interfaces) {
3271 if ((res = c.getField0(name)) != null) {
3272 return res;
3273 }
3274 }
3275 // Direct superclass, recursively
3276 if (!isInterface()) {
3277 Class<?> c = getSuperclass();
3278 if (c != null) {
3279 if ((res = c.getField0(name)) != null) {
3280 return res;
3281 }
3282 }
3283 }
3284 return null;
3285 }
3286
3287 // This method does not copy the returned Method object!
3288 private static Method searchMethods(Method[] methods,
3289 String name,
3290 Class<?>[] parameterTypes)
3291 {
3292 ReflectionFactory fact = getReflectionFactory();
3293 Method res = null;
3294 for (Method m : methods) {
3295 if (m.getName().equals(name)
3296 && arrayContentsEq(parameterTypes,
3297 fact.getExecutableSharedParameterTypes(m))
3298 && (res == null
3299 || (res.getReturnType() != m.getReturnType()
3300 && res.getReturnType().isAssignableFrom(m.getReturnType()))))
3301 res = m;
3302 }
3303 return res;
3304 }
3305
3306 private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
3307
3308 // Returns a "root" Method object. This Method object must NOT
3309 // be propagated to the outside world, but must instead be copied
3310 // via ReflectionFactory.copyMethod.
3311 private Method getMethod0(String name, Class<?>[] parameterTypes) {
3312 PublicMethods.MethodList res = getMethodsRecursive(
3313 name,
3314 parameterTypes == null ? EMPTY_CLASS_ARRAY : parameterTypes,
3315 /* includeStatic */ true);
3316 return res == null ? null : res.getMostSpecific();
3317 }
3318
3319 // Returns a list of "root" Method objects. These Method objects must NOT
3320 // be propagated to the outside world, but must instead be copied
3321 // via ReflectionFactory.copyMethod.
3322 private PublicMethods.MethodList getMethodsRecursive(String name,
3323 Class<?>[] parameterTypes,
3324 boolean includeStatic) {
3325 // 1st check declared public methods
3326 Method[] methods = privateGetDeclaredMethods(/* publicOnly */ true);
3327 PublicMethods.MethodList res = PublicMethods.MethodList
3328 .filter(methods, name, parameterTypes, includeStatic);
3329 // if there is at least one match among declared methods, we need not
3330 // search any further as such match surely overrides matching methods
3331 // declared in superclass(es) or interface(s).
3332 if (res != null) {
3333 return res;
3334 }
3335
3336 // if there was no match among declared methods,
3337 // we must consult the superclass (if any) recursively...
3338 Class<?> sc = getSuperclass();
3339 if (sc != null) {
3340 res = sc.getMethodsRecursive(name, parameterTypes, includeStatic);
3341 }
3342
3343 // ...and coalesce the superclass methods with methods obtained
3344 // from directly implemented interfaces excluding static methods...
3345 for (Class<?> intf : getInterfaces(/* cloneArray */ false)) {
3346 res = PublicMethods.MethodList.merge(
3347 res, intf.getMethodsRecursive(name, parameterTypes,
3348 /* includeStatic */ false));
3349 }
3350
3351 return res;
3352 }
3353
3354 // Returns a "root" Constructor object. This Constructor object must NOT
3355 // be propagated to the outside world, but must instead be copied
3356 // via ReflectionFactory.copyConstructor.
3357 private Constructor<T> getConstructor0(Class<?>[] parameterTypes,
3358 int which) throws NoSuchMethodException
3359 {
3360 ReflectionFactory fact = getReflectionFactory();
3361 Constructor<T>[] constructors = privateGetDeclaredConstructors((which == Member.PUBLIC));
3362 for (Constructor<T> constructor : constructors) {
3363 if (arrayContentsEq(parameterTypes,
3364 fact.getExecutableSharedParameterTypes(constructor))) {
3365 return constructor;
3366 }
3367 }
3368 throw new NoSuchMethodException(methodToString("<init>", parameterTypes));
3369 }
3370
3371 //
3372 // Other helpers and base implementation
3373 //
3374
3375 private static boolean arrayContentsEq(Object[] a1, Object[] a2) {
3376 if (a1 == null) {
3377 return a2 == null || a2.length == 0;
3378 }
3379
3380 if (a2 == null) {
3381 return a1.length == 0;
3382 }
3383
3384 if (a1.length != a2.length) {
3385 return false;
3386 }
3387
3388 for (int i = 0; i < a1.length; i++) {
3389 if (a1[i] != a2[i]) {
3390 return false;
3391 }
3392 }
3393
3394 return true;
3395 }
3396
3397 private static Field[] copyFields(Field[] arg) {
3398 Field[] out = new Field[arg.length];
3399 ReflectionFactory fact = getReflectionFactory();
3400 for (int i = 0; i < arg.length; i++) {
3401 out[i] = fact.copyField(arg[i]);
3402 }
3403 return out;
3404 }
3405
3406 private static Method[] copyMethods(Method[] arg) {
3407 Method[] out = new Method[arg.length];
3408 ReflectionFactory fact = getReflectionFactory();
3409 for (int i = 0; i < arg.length; i++) {
3410 out[i] = fact.copyMethod(arg[i]);
3411 }
3412 return out;
3413 }
3414
3415 private static <U> Constructor<U>[] copyConstructors(Constructor<U>[] arg) {
3416 Constructor<U>[] out = arg.clone();
3417 ReflectionFactory fact = getReflectionFactory();
3418 for (int i = 0; i < out.length; i++) {
3419 out[i] = fact.copyConstructor(out[i]);
3420 }
3421 return out;
3422 }
3423
3424 private native Field[] getDeclaredFields0(boolean publicOnly);
3425 private native Method[] getDeclaredMethods0(boolean publicOnly);
3426 private native Constructor<T>[] getDeclaredConstructors0(boolean publicOnly);
3427 private native Class<?>[] getDeclaredClasses0();
3428
3429 /**
3430 * Helper method to get the method name from arguments.
3431 */
3432 private String methodToString(String name, Class<?>[] argTypes) {
3433 return getName() + '.' + name +
3434 ((argTypes == null || argTypes.length == 0) ?
3435 "()" :
3436 Arrays.stream(argTypes)
3437 .map(c -> c == null ? "null" : c.getName())
3438 .collect(Collectors.joining(",", "(", ")")));
3439 }
3440
3441 /** use serialVersionUID from JDK 1.1 for interoperability */
3442 @java.io.Serial
3443 private static final long serialVersionUID = 3206093459760846163L;
3444
3445
3446 /**
3447 * Class Class is special cased within the Serialization Stream Protocol.
3448 *
3449 * A Class instance is written initially into an ObjectOutputStream in the
3450 * following format:
3451 * <pre>
3452 * {@code TC_CLASS} ClassDescriptor
3453 * A ClassDescriptor is a special cased serialization of
3454 * a {@code java.io.ObjectStreamClass} instance.
3455 * </pre>
3456 * A new handle is generated for the initial time the class descriptor
3457 * is written into the stream. Future references to the class descriptor
3458 * are written as references to the initial class descriptor instance.
3459 *
3460 * @see java.io.ObjectStreamClass
3461 */
3462 @java.io.Serial
3463 private static final ObjectStreamField[] serialPersistentFields =
3464 new ObjectStreamField[0];
3465
3466
3467 /**
3468 * Returns the assertion status that would be assigned to this
3469 * class if it were to be initialized at the time this method is invoked.
3470 * If this class has had its assertion status set, the most recent
3471 * setting will be returned; otherwise, if any package default assertion
3472 * status pertains to this class, the most recent setting for the most
3473 * specific pertinent package default assertion status is returned;
3474 * otherwise, if this class is not a system class (i.e., it has a
3475 * class loader) its class loader's default assertion status is returned;
3476 * otherwise, the system class default assertion status is returned.
3477 * <p>
3478 * Few programmers will have any need for this method; it is provided
3479 * for the benefit of the JRE itself. (It allows a class to determine at
3480 * the time that it is initialized whether assertions should be enabled.)
3481 * Note that this method is not guaranteed to return the actual
3482 * assertion status that was (or will be) associated with the specified
3483 * class when it was (or will be) initialized.
3484 *
3485 * @return the desired assertion status of the specified class.
3486 * @see java.lang.ClassLoader#setClassAssertionStatus
3487 * @see java.lang.ClassLoader#setPackageAssertionStatus
3488 * @see java.lang.ClassLoader#setDefaultAssertionStatus
3489 * @since 1.4
3490 */
3491 public boolean desiredAssertionStatus() {
3492 ClassLoader loader = getClassLoader0();
3493 // If the loader is null this is a system class, so ask the VM
3494 if (loader == null)
3495 return desiredAssertionStatus0(this);
3496
3497 // If the classloader has been initialized with the assertion
3498 // directives, ask it. Otherwise, ask the VM.
3499 synchronized(loader.assertionLock) {
3500 if (loader.classAssertionStatus != null) {
3501 return loader.desiredAssertionStatus(getName());
3502 }
3503 }
3504 return desiredAssertionStatus0(this);
3505 }
3506
3507 // Retrieves the desired assertion status of this class from the VM
3508 private static native boolean desiredAssertionStatus0(Class<?> clazz);
3509
3510 /**
3511 * Returns true if and only if this class was declared as an enum in the
3512 * source code.
3513 *
3514 * Note that if an enum constant is declared with a class body,
3515 * the class of that enum constant object is an anonymous class
3516 * and <em>not</em> the class of the declaring enum type. The
3517 * {@link Enum#getDeclaringClass} method of an enum constant can
3518 * be used to get the class of the enum type declaring the
3519 * constant.
3520 *
3521 * @return true if and only if this class was declared as an enum in the
3522 * source code
3523 * @since 1.5
3524 * @jls 8.9.1 Enum Constants
3525 */
3526 public boolean isEnum() {
3527 // An enum must both directly extend java.lang.Enum and have
3528 // the ENUM bit set; classes for specialized enum constants
3529 // don't do the former.
3530 return (this.getModifiers() & ENUM) != 0 &&
3531 this.getSuperclass() == java.lang.Enum.class;
3532 }
3533
3534 // Fetches the factory for reflective objects
3535 private static ReflectionFactory getReflectionFactory() {
3536 if (reflectionFactory == null) {
3537 reflectionFactory =
3538 java.security.AccessController.doPrivileged
3539 (new ReflectionFactory.GetReflectionFactoryAction());
3540 }
3541 return reflectionFactory;
3542 }
3543 private static ReflectionFactory reflectionFactory;
3544
3545 /**
3546 * Returns the elements of this enum class or null if this
3547 * Class object does not represent an enum type.
3548 *
3549 * @return an array containing the values comprising the enum class
3550 * represented by this Class object in the order they're
3551 * declared, or null if this Class object does not
3552 * represent an enum type
3553 * @since 1.5
3554 */
3555 public T[] getEnumConstants() {
3556 T[] values = getEnumConstantsShared();
3557 return (values != null) ? values.clone() : null;
3558 }
3559
3560 /**
3561 * Returns the elements of this enum class or null if this
3562 * Class object does not represent an enum type;
3563 * identical to getEnumConstants except that the result is
3564 * uncloned, cached, and shared by all callers.
3565 */
3566 T[] getEnumConstantsShared() {
3567 T[] constants = enumConstants;
3568 if (constants == null) {
3569 if (!isEnum()) return null;
3570 try {
3571 final Method values = getMethod("values");
3572 java.security.AccessController.doPrivileged(
3573 new java.security.PrivilegedAction<>() {
3574 public Void run() {
3575 values.setAccessible(true);
3576 return null;
3577 }
3578 });
3579 @SuppressWarnings("unchecked")
3580 T[] temporaryConstants = (T[])values.invoke(null);
3581 enumConstants = constants = temporaryConstants;
3582 }
3583 // These can happen when users concoct enum-like classes
3584 // that don't comply with the enum spec.
3585 catch (InvocationTargetException | NoSuchMethodException |
3586 IllegalAccessException ex) { return null; }
3587 }
3588 return constants;
3589 }
3590 private transient volatile T[] enumConstants;
3591
3592 /**
3593 * Returns a map from simple name to enum constant. This package-private
3594 * method is used internally by Enum to implement
3595 * {@code public static <T extends Enum<T>> T valueOf(Class<T>, String)}
3596 * efficiently. Note that the map is returned by this method is
3597 * created lazily on first use. Typically it won't ever get created.
3598 */
3599 Map<String, T> enumConstantDirectory() {
3600 Map<String, T> directory = enumConstantDirectory;
3601 if (directory == null) {
3602 T[] universe = getEnumConstantsShared();
3603 if (universe == null)
3604 throw new IllegalArgumentException(
3605 getName() + " is not an enum type");
3606 directory = new HashMap<>((int)(universe.length / 0.75f) + 1);
3607 for (T constant : universe) {
3608 directory.put(((Enum<?>)constant).name(), constant);
3609 }
3610 enumConstantDirectory = directory;
3611 }
3612 return directory;
3613 }
3614 private transient volatile Map<String, T> enumConstantDirectory;
3615
3616 /**
3617 * Casts an object to the class or interface represented
3618 * by this {@code Class} object.
3619 *
3620 * @param obj the object to be cast
3621 * @return the object after casting, or null if obj is null
3622 *
3623 * @throws ClassCastException if the object is not
3624 * null and is not assignable to the type T.
3625 *
3626 * @since 1.5
3627 */
3628 @SuppressWarnings("unchecked")
3629 @HotSpotIntrinsicCandidate
3630 public T cast(Object obj) {
3631 if (obj != null && !isInstance(obj))
3632 throw new ClassCastException(cannotCastMsg(obj));
3633 return (T) obj;
3634 }
3635
3636 private String cannotCastMsg(Object obj) {
3637 return "Cannot cast " + obj.getClass().getName() + " to " + getName();
3638 }
3639
3640 /**
3641 * Casts this {@code Class} object to represent a subclass of the class
3642 * represented by the specified class object. Checks that the cast
3643 * is valid, and throws a {@code ClassCastException} if it is not. If
3644 * this method succeeds, it always returns a reference to this class object.
3645 *
3646 * <p>This method is useful when a client needs to "narrow" the type of
3647 * a {@code Class} object to pass it to an API that restricts the
3648 * {@code Class} objects that it is willing to accept. A cast would
3649 * generate a compile-time warning, as the correctness of the cast
3650 * could not be checked at runtime (because generic types are implemented
3651 * by erasure).
3652 *
3653 * @param <U> the type to cast this class object to
3654 * @param clazz the class of the type to cast this class object to
3655 * @return this {@code Class} object, cast to represent a subclass of
3656 * the specified class object.
3657 * @throws ClassCastException if this {@code Class} object does not
3658 * represent a subclass of the specified class (here "subclass" includes
3659 * the class itself).
3660 * @since 1.5
3661 */
3662 @SuppressWarnings("unchecked")
3663 public <U> Class<? extends U> asSubclass(Class<U> clazz) {
3664 if (clazz.isAssignableFrom(this))
3665 return (Class<? extends U>) this;
3666 else
3667 throw new ClassCastException(this.toString());
3668 }
3669
3670 /**
3671 * @throws NullPointerException {@inheritDoc}
3672 * @since 1.5
3673 */
3674 @SuppressWarnings("unchecked")
3675 public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
3676 Objects.requireNonNull(annotationClass);
3677
3678 return (A) annotationData().annotations.get(annotationClass);
3679 }
3680
3681 /**
3682 * {@inheritDoc}
3683 * @throws NullPointerException {@inheritDoc}
3684 * @since 1.5
3685 */
3686 @Override
3687 public boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
3688 return GenericDeclaration.super.isAnnotationPresent(annotationClass);
3689 }
3690
3691 /**
3692 * @throws NullPointerException {@inheritDoc}
3693 * @since 1.8
3694 */
3695 @Override
3696 public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationClass) {
3697 Objects.requireNonNull(annotationClass);
3698
3699 AnnotationData annotationData = annotationData();
3700 return AnnotationSupport.getAssociatedAnnotations(annotationData.declaredAnnotations,
3701 this,
3702 annotationClass);
3703 }
3704
3705 /**
3706 * @since 1.5
3707 */
3708 public Annotation[] getAnnotations() {
3709 return AnnotationParser.toArray(annotationData().annotations);
3710 }
3711
3712 /**
3713 * @throws NullPointerException {@inheritDoc}
3714 * @since 1.8
3715 */
3716 @Override
3717 @SuppressWarnings("unchecked")
3718 public <A extends Annotation> A getDeclaredAnnotation(Class<A> annotationClass) {
3719 Objects.requireNonNull(annotationClass);
3720
3721 return (A) annotationData().declaredAnnotations.get(annotationClass);
3722 }
3723
3724 /**
3725 * @throws NullPointerException {@inheritDoc}
3726 * @since 1.8
3727 */
3728 @Override
3729 public <A extends Annotation> A[] getDeclaredAnnotationsByType(Class<A> annotationClass) {
3730 Objects.requireNonNull(annotationClass);
3731
3732 return AnnotationSupport.getDirectlyAndIndirectlyPresent(annotationData().declaredAnnotations,
3733 annotationClass);
3734 }
3735
3736 /**
3737 * @since 1.5
3738 */
3739 public Annotation[] getDeclaredAnnotations() {
3740 return AnnotationParser.toArray(annotationData().declaredAnnotations);
3741 }
3742
3743 // annotation data that might get invalidated when JVM TI RedefineClasses() is called
3744 private static class AnnotationData {
3745 final Map<Class<? extends Annotation>, Annotation> annotations;
3746 final Map<Class<? extends Annotation>, Annotation> declaredAnnotations;
3747
3748 // Value of classRedefinedCount when we created this AnnotationData instance
3749 final int redefinedCount;
3750
3751 AnnotationData(Map<Class<? extends Annotation>, Annotation> annotations,
3752 Map<Class<? extends Annotation>, Annotation> declaredAnnotations,
3753 int redefinedCount) {
3754 this.annotations = annotations;
3755 this.declaredAnnotations = declaredAnnotations;
3756 this.redefinedCount = redefinedCount;
3757 }
3758 }
3759
3760 // Annotations cache
3761 @SuppressWarnings("UnusedDeclaration")
3762 private transient volatile AnnotationData annotationData;
3763
3764 private AnnotationData annotationData() {
3765 while (true) { // retry loop
3766 AnnotationData annotationData = this.annotationData;
3767 int classRedefinedCount = this.classRedefinedCount;
3768 if (annotationData != null &&
3769 annotationData.redefinedCount == classRedefinedCount) {
3770 return annotationData;
3771 }
3772 // null or stale annotationData -> optimistically create new instance
3773 AnnotationData newAnnotationData = createAnnotationData(classRedefinedCount);
3774 // try to install it
3775 if (Atomic.casAnnotationData(this, annotationData, newAnnotationData)) {
3776 // successfully installed new AnnotationData
3777 return newAnnotationData;
3778 }
3779 }
3780 }
3781
3782 private AnnotationData createAnnotationData(int classRedefinedCount) {
3783 Map<Class<? extends Annotation>, Annotation> declaredAnnotations =
3784 AnnotationParser.parseAnnotations(getRawAnnotations(), getConstantPool(), this);
3785 Class<?> superClass = getSuperclass();
3786 Map<Class<? extends Annotation>, Annotation> annotations = null;
3787 if (superClass != null) {
3788 Map<Class<? extends Annotation>, Annotation> superAnnotations =
3789 superClass.annotationData().annotations;
3790 for (Map.Entry<Class<? extends Annotation>, Annotation> e : superAnnotations.entrySet()) {
3791 Class<? extends Annotation> annotationClass = e.getKey();
3792 if (AnnotationType.getInstance(annotationClass).isInherited()) {
3793 if (annotations == null) { // lazy construction
3794 annotations = new LinkedHashMap<>((Math.max(
3795 declaredAnnotations.size(),
3796 Math.min(12, declaredAnnotations.size() + superAnnotations.size())
3797 ) * 4 + 2) / 3
3798 );
3799 }
3800 annotations.put(annotationClass, e.getValue());
3801 }
3802 }
3803 }
3804 if (annotations == null) {
3805 // no inherited annotations -> share the Map with declaredAnnotations
3806 annotations = declaredAnnotations;
3807 } else {
3808 // at least one inherited annotation -> declared may override inherited
3809 annotations.putAll(declaredAnnotations);
3810 }
3811 return new AnnotationData(annotations, declaredAnnotations, classRedefinedCount);
3812 }
3813
3814 // Annotation types cache their internal (AnnotationType) form
3815
3816 @SuppressWarnings("UnusedDeclaration")
3817 private transient volatile AnnotationType annotationType;
3818
3819 boolean casAnnotationType(AnnotationType oldType, AnnotationType newType) {
3820 return Atomic.casAnnotationType(this, oldType, newType);
3821 }
3822
3823 AnnotationType getAnnotationType() {
3824 return annotationType;
3825 }
3826
3827 Map<Class<? extends Annotation>, Annotation> getDeclaredAnnotationMap() {
3828 return annotationData().declaredAnnotations;
3829 }
3830
3831 /* Backing store of user-defined values pertaining to this class.
3832 * Maintained by the ClassValue class.
3833 */
3834 transient ClassValue.ClassValueMap classValueMap;
3835
3836 /**
3837 * Returns an {@code AnnotatedType} object that represents the use of a
3838 * type to specify the superclass of the entity represented by this {@code
3839 * Class} object. (The <em>use</em> of type Foo to specify the superclass
3840 * in '... extends Foo' is distinct from the <em>declaration</em> of type
3841 * Foo.)
3842 *
3843 * <p> If this {@code Class} object represents a type whose declaration
3844 * does not explicitly indicate an annotated superclass, then the return
3845 * value is an {@code AnnotatedType} object representing an element with no
3846 * annotations.
3847 *
3848 * <p> If this {@code Class} represents either the {@code Object} class, an
3849 * interface type, an array type, a primitive type, or void, the return
3850 * value is {@code null}.
3851 *
3852 * @return an object representing the superclass
3853 * @since 1.8
3854 */
3855 public AnnotatedType getAnnotatedSuperclass() {
3856 if (this == Object.class ||
3857 isInterface() ||
3858 isArray() ||
3859 isPrimitive() ||
3860 this == Void.TYPE) {
3861 return null;
3862 }
3863
3864 return TypeAnnotationParser.buildAnnotatedSuperclass(getRawTypeAnnotations(), getConstantPool(), this);
3865 }
3866
3867 /**
3868 * Returns an array of {@code AnnotatedType} objects that represent the use
3869 * of types to specify superinterfaces of the entity represented by this
3870 * {@code Class} object. (The <em>use</em> of type Foo to specify a
3871 * superinterface in '... implements Foo' is distinct from the
3872 * <em>declaration</em> of type Foo.)
3873 *
3874 * <p> If this {@code Class} object represents a class, the return value is
3875 * an array containing objects representing the uses of interface types to
3876 * specify interfaces implemented by the class. The order of the objects in
3877 * the array corresponds to the order of the interface types used in the
3878 * 'implements' clause of the declaration of this {@code Class} object.
3879 *
3880 * <p> If this {@code Class} object represents an interface, the return
3881 * value is an array containing objects representing the uses of interface
3882 * types to specify interfaces directly extended by the interface. The
3883 * order of the objects in the array corresponds to the order of the
3884 * interface types used in the 'extends' clause of the declaration of this
3885 * {@code Class} object.
3886 *
3887 * <p> If this {@code Class} object represents a class or interface whose
3888 * declaration does not explicitly indicate any annotated superinterfaces,
3889 * the return value is an array of length 0.
3890 *
3891 * <p> If this {@code Class} object represents either the {@code Object}
3892 * class, an array type, a primitive type, or void, the return value is an
3893 * array of length 0.
3894 *
3895 * @return an array representing the superinterfaces
3896 * @since 1.8
3897 */
3898 public AnnotatedType[] getAnnotatedInterfaces() {
3899 return TypeAnnotationParser.buildAnnotatedInterfaces(getRawTypeAnnotations(), getConstantPool(), this);
3900 }
3901
3902 private native Class<?> getNestHost0();
3903
3904 /**
3905 * Returns the nest host of the <a href=#nest>nest</a> to which the class
3906 * or interface represented by this {@code Class} object belongs.
3907 * Every class and interface is a member of exactly one nest.
3908 * A class or interface that is not recorded as belonging to a nest
3909 * belongs to the nest consisting only of itself, and is the nest
3910 * host.
3911 *
3912 * <p>Each of the {@code Class} objects representing array types,
3913 * primitive types, and {@code void} returns {@code this} to indicate
3914 * that the represented entity belongs to the nest consisting only of
3915 * itself, and is the nest host.
3916 *
3917 * <p>If there is a {@linkplain LinkageError linkage error} accessing
3918 * the nest host, or if this class or interface is not enumerated as
3919 * a member of the nest by the nest host, then it is considered to belong
3920 * to its own nest and {@code this} is returned as the host.
3921 *
3922 * @apiNote A {@code class} file of version 55.0 or greater may record the
3923 * host of the nest to which it belongs by using the {@code NestHost}
3924 * attribute (JVMS 4.7.28). Alternatively, a {@code class} file of
3925 * version 55.0 or greater may act as a nest host by enumerating the nest's
3926 * other members with the
3927 * {@code NestMembers} attribute (JVMS 4.7.29).
3928 * A {@code class} file of version 54.0 or lower does not use these
3929 * attributes.
3930 *
3931 * @return the nest host of this class or interface
3932 *
3933 * @throws SecurityException
3934 * If the returned class is not the current class, and
3935 * if a security manager, <i>s</i>, is present and the caller's
3936 * class loader is not the same as or an ancestor of the class
3937 * loader for the returned class and invocation of {@link
3938 * SecurityManager#checkPackageAccess s.checkPackageAccess()}
3939 * denies access to the package of the returned class
3940 * @since 11
3941 * @jvms 4.7.28 The {@code NestHost} Attribute
3942 * @jvms 4.7.29 The {@code NestMembers} Attribute
3943 * @jvms 5.4.4 Access Control
3944 */
3945 @CallerSensitive
3946 public Class<?> getNestHost() {
3947 if (isPrimitive() || isArray()) {
3948 return this;
3949 }
3950 Class<?> host;
3951 try {
3952 host = getNestHost0();
3953 } catch (LinkageError e) {
3954 // if we couldn't load our nest-host then we
3955 // act as-if we have no nest-host attribute
3956 return this;
3957 }
3958 // if null then nest membership validation failed, so we
3959 // act as-if we have no nest-host attribute
3960 if (host == null || host == this) {
3961 return this;
3962 }
3963 // returning a different class requires a security check
3964 SecurityManager sm = System.getSecurityManager();
3965 if (sm != null) {
3966 checkPackageAccess(sm,
3967 ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
3968 }
3969 return host;
3970 }
3971
3972 /**
3973 * Determines if the given {@code Class} is a nestmate of the
3974 * class or interface represented by this {@code Class} object.
3975 * Two classes or interfaces are nestmates
3976 * if they have the same {@linkplain #getNestHost() nest host}.
3977 *
3978 * @param c the class to check
3979 * @return {@code true} if this class and {@code c} are members of
3980 * the same nest; and {@code false} otherwise.
3981 *
3982 * @since 11
3983 */
3984 public boolean isNestmateOf(Class<?> c) {
3985 if (this == c) {
3986 return true;
3987 }
3988 if (isPrimitive() || isArray() ||
3989 c.isPrimitive() || c.isArray()) {
3990 return false;
3991 }
3992 try {
3993 return getNestHost0() == c.getNestHost0();
3994 } catch (LinkageError e) {
3995 return false;
3996 }
3997 }
3998
3999 private native Class<?>[] getNestMembers0();
4000
4001 /**
4002 * Returns an array containing {@code Class} objects representing all the
4003 * classes and interfaces that are members of the nest to which the class
4004 * or interface represented by this {@code Class} object belongs.
4005 * The {@linkplain #getNestHost() nest host} of that nest is the zeroth
4006 * element of the array. Subsequent elements represent any classes or
4007 * interfaces that are recorded by the nest host as being members of
4008 * the nest; the order of such elements is unspecified. Duplicates are
4009 * permitted.
4010 * If the nest host of that nest does not enumerate any members, then the
4011 * array has a single element containing {@code this}.
4012 *
4013 * <p>Each of the {@code Class} objects representing array types,
4014 * primitive types, and {@code void} returns an array containing only
4015 * {@code this}.
4016 *
4017 * <p>This method validates that, for each class or interface which is
4018 * recorded as a member of the nest by the nest host, that class or
4019 * interface records itself as a member of that same nest. Any exceptions
4020 * that occur during this validation are rethrown by this method.
4021 *
4022 * @return an array of all classes and interfaces in the same nest as
4023 * this class
4024 *
4025 * @throws LinkageError
4026 * If there is any problem loading or validating a nest member or
4027 * its nest host
4028 * @throws SecurityException
4029 * If any returned class is not the current class, and
4030 * if a security manager, <i>s</i>, is present and the caller's
4031 * class loader is not the same as or an ancestor of the class
4032 * loader for that returned class and invocation of {@link
4033 * SecurityManager#checkPackageAccess s.checkPackageAccess()}
4034 * denies access to the package of that returned class
4035 *
4036 * @since 11
4037 * @see #getNestHost()
4038 */
4039 @CallerSensitive
4040 public Class<?>[] getNestMembers() {
4041 if (isPrimitive() || isArray()) {
4042 return new Class<?>[] { this };
4043 }
4044 Class<?>[] members = getNestMembers0();
4045 // Can't actually enable this due to bootstrapping issues
4046 // assert(members.length != 1 || members[0] == this); // expected invariant from VM
4047
4048 if (members.length > 1) {
4049 // If we return anything other than the current class we need
4050 // a security check
4051 SecurityManager sm = System.getSecurityManager();
4052 if (sm != null) {
4053 checkPackageAccess(sm,
4054 ClassLoader.getClassLoader(Reflection.getCallerClass()), true);
4055 }
4056 }
4057 return members;
4058 }
4059
4060 /**
4061 * Returns the type descriptor string for this class.
4062 * <p>
4063 * Note that this is not a strict inverse of {@link #forName};
4064 * distinct classes which share a common name but have different class loaders
4065 * will have identical descriptor strings.
4066 *
4067 * @return the type descriptor representation
4068 * @jvms 4.3.2 Field Descriptors
4069 * @since 12
4070 */
4071 @Override
4072 public String descriptorString() {
4073 if (isPrimitive())
4074 return Wrapper.forPrimitiveType(this).basicTypeString();
4075 else if (isArray()) {
4076 return "[" + componentType.descriptorString();
4077 }
4078 else {
4079 return "L" + getName().replace('.', '/') + ";";
4080 }
4081 }
4082
4083 /**
4084 * Returns the component type of this {@code Class}, if it describes
4085 * an array type, or {@code null} otherwise.
4086 *
4087 * @implSpec
4088 * Equivalent to {@link Class#getComponentType()}.
4089 *
4090 * @return a {@code Class} describing the component type, or {@code null}
4091 * if this {@code Class} does not describe an array type
4092 * @since 12
4093 */
4094 @Override
4095 public Class<?> componentType() {
4096 return isArray() ? componentType : null;
4097 }
4098
4099 /**
4100 * Returns a {@code Class} for an array type whose component type
4101 * is described by this {@linkplain Class}.
4102 *
4103 * @return a {@code Class} describing the array type
4104 * @since 12
4105 */
4106 @Override
4107 public Class<?> arrayType() {
4108 return Array.newInstance(this, 0).getClass();
4109 }
4110
4111 /**
4112 * Returns a nominal descriptor for this instance, if one can be
4113 * constructed, or an empty {@link Optional} if one cannot be.
4114 *
4115 * @return An {@link Optional} containing the resulting nominal descriptor,
4116 * or an empty {@link Optional} if one cannot be constructed.
4117 * @since 12
4118 */
4119 @Override
4120 public Optional<ClassDesc> describeConstable() {
4121 return Optional.of(ClassDesc.ofDescriptor(descriptorString()));
4122 }
4123 }