1 /*
2 * Copyright (c) 1996, 2023, 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.reflect;
27
28 import jdk.internal.access.SharedSecrets;
29 import jdk.internal.value.PrimitiveClass;
30 import jdk.internal.misc.VM;
31 import jdk.internal.reflect.CallerSensitive;
32 import jdk.internal.reflect.CallerSensitiveAdapter;
33 import jdk.internal.reflect.MethodAccessor;
34 import jdk.internal.reflect.Reflection;
35 import jdk.internal.vm.annotation.ForceInline;
36 import jdk.internal.vm.annotation.IntrinsicCandidate;
37 import jdk.internal.vm.annotation.Stable;
38 import sun.reflect.annotation.ExceptionProxy;
39 import sun.reflect.annotation.TypeNotPresentExceptionProxy;
40 import sun.reflect.generics.repository.GenericDeclRepository;
41 import sun.reflect.generics.repository.MethodRepository;
42 import sun.reflect.generics.factory.CoreReflectionFactory;
43 import sun.reflect.generics.factory.GenericsFactory;
44 import sun.reflect.generics.scope.MethodScope;
45 import sun.reflect.annotation.AnnotationType;
46 import sun.reflect.annotation.AnnotationParser;
47 import java.lang.annotation.Annotation;
48 import java.lang.annotation.AnnotationFormatError;
49 import java.nio.ByteBuffer;
50 import java.util.StringJoiner;
51
52 /**
53 * A {@code Method} provides information about, and access to, a single method
54 * on a class or interface. The reflected method may be a class method
55 * or an instance method (including an abstract method).
56 *
57 * <p>A {@code Method} permits widening conversions to occur when matching the
58 * actual parameters to invoke with the underlying method's formal
59 * parameters, but it throws an {@code IllegalArgumentException} if a
60 * narrowing conversion would occur.
61 *
62 * @see Member
63 * @see java.lang.Class
64 * @see java.lang.Class#getMethods()
65 * @see java.lang.Class#getMethod(String, Class[])
66 * @see java.lang.Class#getDeclaredMethods()
67 * @see java.lang.Class#getDeclaredMethod(String, Class[])
68 *
69 * @author Kenneth Russell
70 * @author Nakul Saraiya
71 * @since 1.1
72 */
73 public final class Method extends Executable {
74 private final Class<?> clazz;
75 private final int slot;
76 // This is guaranteed to be interned by the VM in the 1.4
77 // reflection implementation
78 private final String name;
79 private final Class<?> returnType;
80 private final Class<?>[] parameterTypes;
81 private final Class<?>[] exceptionTypes;
82 private final int modifiers;
83 // Generics and annotations support
84 private final transient String signature;
85 // generic info repository; lazily initialized
86 private transient volatile MethodRepository genericInfo;
87 private final byte[] annotations;
88 private final byte[] parameterAnnotations;
89 private final byte[] annotationDefault;
90 @Stable
91 private MethodAccessor methodAccessor;
92 // For sharing of MethodAccessors. This branching structure is
93 // currently only two levels deep (i.e., one root Method and
94 // potentially many Method objects pointing to it.)
95 //
96 // If this branching structure would ever contain cycles, deadlocks can
97 // occur in annotation code.
98 private Method root;
99
100 // Generics infrastructure
101 private String getGenericSignature() {return signature;}
102
103 // Accessor for factory
104 private GenericsFactory getFactory() {
105 // create scope and factory
106 return CoreReflectionFactory.make(this, MethodScope.make(this));
107 }
108
109 // Accessor for generic info repository
110 @Override
111 MethodRepository getGenericInfo() {
112 var genericInfo = this.genericInfo;
113 // lazily initialize repository if necessary
114 if (genericInfo == null) {
115 // create and cache generic info repository
116 genericInfo = MethodRepository.make(getGenericSignature(),
117 getFactory());
118 this.genericInfo = genericInfo;
119 }
120 return genericInfo; //return cached repository
121 }
122
123 /**
124 * Package-private constructor
125 */
126 Method(Class<?> declaringClass,
127 String name,
128 Class<?>[] parameterTypes,
129 Class<?> returnType,
130 Class<?>[] checkedExceptions,
131 int modifiers,
132 int slot,
133 String signature,
134 byte[] annotations,
135 byte[] parameterAnnotations,
136 byte[] annotationDefault) {
137 assert PrimitiveClass.isPrimaryType(declaringClass);
138 this.clazz = declaringClass;
139 this.name = name;
140 this.parameterTypes = parameterTypes;
141 this.returnType = returnType;
142 this.exceptionTypes = checkedExceptions;
143 this.modifiers = modifiers;
144 this.slot = slot;
145 this.signature = signature;
146 this.annotations = annotations;
147 this.parameterAnnotations = parameterAnnotations;
148 this.annotationDefault = annotationDefault;
149 }
150
151 /**
152 * Package-private routine (exposed to java.lang.Class via
153 * ReflectAccess) which returns a copy of this Method. The copy's
154 * "root" field points to this Method.
155 */
156 Method copy() {
157 // This routine enables sharing of MethodAccessor objects
158 // among Method objects which refer to the same underlying
159 // method in the VM. (All of this contortion is only necessary
160 // because of the "accessibility" bit in AccessibleObject,
161 // which implicitly requires that new java.lang.reflect
162 // objects be fabricated for each reflective call on Class
163 // objects.)
164 if (this.root != null)
165 throw new IllegalArgumentException("Can not copy a non-root Method");
166
167 Method res = new Method(clazz, name, parameterTypes, returnType,
168 exceptionTypes, modifiers, slot, signature,
169 annotations, parameterAnnotations, annotationDefault);
170 res.root = this;
171 // Might as well eagerly propagate this if already present
172 res.methodAccessor = methodAccessor;
173 return res;
174 }
175
176 /**
177 * Make a copy of a leaf method.
178 */
179 Method leafCopy() {
180 if (this.root == null)
181 throw new IllegalArgumentException("Can only leafCopy a non-root Method");
182
183 Method res = new Method(clazz, name, parameterTypes, returnType,
184 exceptionTypes, modifiers, slot, signature,
185 annotations, parameterAnnotations, annotationDefault);
186 res.root = root;
187 res.methodAccessor = methodAccessor;
188 return res;
189 }
190
191 /**
192 * @throws InaccessibleObjectException {@inheritDoc}
193 * @throws SecurityException {@inheritDoc}
194 */
195 @Override
196 @CallerSensitive
197 public void setAccessible(boolean flag) {
198 AccessibleObject.checkPermission();
199 if (flag) checkCanSetAccessible(Reflection.getCallerClass());
200 setAccessible0(flag);
201 }
202
203 @Override
204 void checkCanSetAccessible(Class<?> caller) {
205 checkCanSetAccessible(caller, clazz);
206 }
207
208 @Override
209 Method getRoot() {
210 return root;
211 }
212
213 @Override
214 boolean hasGenericInformation() {
215 return (getGenericSignature() != null);
216 }
217
218 @Override
219 byte[] getAnnotationBytes() {
220 return annotations;
221 }
222
223 /**
224 * Returns the {@code Class} object representing the class or interface
225 * that declares the method represented by this object.
226 */
227 @Override
228 public Class<?> getDeclaringClass() {
229 return clazz;
230 }
231
232 /**
233 * Returns the name of the method represented by this {@code Method}
234 * object, as a {@code String}.
235 */
236 @Override
237 public String getName() {
238 return name;
239 }
240
241 /**
242 * {@inheritDoc}
243 * @jls 8.4.3 Method Modifiers
244 */
245 @Override
246 public int getModifiers() {
247 return modifiers;
248 }
249
250 /**
251 * {@inheritDoc}
252 * @throws GenericSignatureFormatError {@inheritDoc}
253 * @since 1.5
254 * @jls 8.4.4 Generic Methods
255 */
256 @Override
257 @SuppressWarnings({"rawtypes", "unchecked"})
258 public TypeVariable<Method>[] getTypeParameters() {
259 if (getGenericSignature() != null)
260 return (TypeVariable<Method>[])getGenericInfo().getTypeParameters();
261 else
262 return (TypeVariable<Method>[])GenericDeclRepository.EMPTY_TYPE_VARS;
263 }
264
265 /**
266 * Returns a {@code Class} object that represents the formal return type
267 * of the method represented by this {@code Method} object.
268 *
269 * @return the return type for the method this object represents
270 */
271 public Class<?> getReturnType() {
272 return returnType;
273 }
274
275 /**
276 * Returns a {@code Type} object that represents the formal return
277 * type of the method represented by this {@code Method} object.
278 *
279 * <p>If the return type is a parameterized type,
280 * the {@code Type} object returned must accurately reflect
281 * the actual type arguments used in the source code.
282 *
283 * <p>If the return type is a type variable or a parameterized type, it
284 * is created. Otherwise, it is resolved.
285 *
286 * @return a {@code Type} object that represents the formal return
287 * type of the underlying method
288 * @throws GenericSignatureFormatError
289 * if the generic method signature does not conform to the format
290 * specified in
291 * <cite>The Java Virtual Machine Specification</cite>
292 * @throws TypeNotPresentException if the underlying method's
293 * return type refers to a non-existent class or interface declaration
294 * @throws MalformedParameterizedTypeException if the
295 * underlying method's return type refers to a parameterized
296 * type that cannot be instantiated for any reason
297 * @since 1.5
298 */
299 public Type getGenericReturnType() {
300 if (getGenericSignature() != null) {
301 return getGenericInfo().getReturnType();
302 } else { return getReturnType();}
303 }
304
305 @Override
306 Class<?>[] getSharedParameterTypes() {
307 return parameterTypes;
308 }
309
310 @Override
311 Class<?>[] getSharedExceptionTypes() {
312 return exceptionTypes;
313 }
314
315 /**
316 * {@inheritDoc}
317 */
318 @Override
319 public Class<?>[] getParameterTypes() {
320 return parameterTypes.clone();
321 }
322
323 /**
324 * {@inheritDoc}
325 * @since 1.8
326 */
327 public int getParameterCount() { return parameterTypes.length; }
328
329
330 /**
331 * {@inheritDoc}
332 * @throws GenericSignatureFormatError {@inheritDoc}
333 * @throws TypeNotPresentException {@inheritDoc}
334 * @throws MalformedParameterizedTypeException {@inheritDoc}
335 * @since 1.5
336 */
337 @Override
338 public Type[] getGenericParameterTypes() {
339 return super.getGenericParameterTypes();
340 }
341
342 /**
343 * {@inheritDoc}
344 */
345 @Override
346 public Class<?>[] getExceptionTypes() {
347 return exceptionTypes.clone();
348 }
349
350 /**
351 * {@inheritDoc}
352 * @throws GenericSignatureFormatError {@inheritDoc}
353 * @throws TypeNotPresentException {@inheritDoc}
354 * @throws MalformedParameterizedTypeException {@inheritDoc}
355 * @since 1.5
356 */
357 @Override
358 public Type[] getGenericExceptionTypes() {
359 return super.getGenericExceptionTypes();
360 }
361
362 /**
363 * Compares this {@code Method} against the specified object. Returns
364 * true if the objects are the same. Two {@code Methods} are the same if
365 * they were declared by the same class and have the same name
366 * and formal parameter types and return type.
367 */
368 public boolean equals(Object obj) {
369 if (obj instanceof Method other) {
370 if ((getDeclaringClass() == other.getDeclaringClass())
371 && (getName() == other.getName())) {
372 if (!returnType.equals(other.getReturnType()))
373 return false;
374 return equalParamTypes(parameterTypes, other.parameterTypes);
375 }
376 }
377 return false;
378 }
379
380 /**
381 * Returns a hashcode for this {@code Method}. The hashcode is computed
382 * as the exclusive-or of the hashcodes for the underlying
383 * method's declaring class name and the method's name.
384 */
385 public int hashCode() {
386 return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
387 }
388
389 /**
390 * Returns a string describing this {@code Method}. The string is
391 * formatted as the method access modifiers, if any, followed by
392 * the method return type, followed by a space, followed by the
393 * class declaring the method, followed by a period, followed by
394 * the method name, followed by a parenthesized, comma-separated
395 * list of the method's formal parameter types. If the method
396 * throws checked exceptions, the parameter list is followed by a
397 * space, followed by the word "{@code throws}" followed by a
398 * comma-separated list of the thrown exception types.
399 * For example:
400 * <pre>
401 * public boolean java.lang.Object.equals(java.lang.Object)
402 * </pre>
403 *
404 * <p>The access modifiers are placed in canonical order as
405 * specified by "The Java Language Specification". This is
406 * {@code public}, {@code protected} or {@code private} first,
407 * and then other modifiers in the following order:
408 * {@code abstract}, {@code default}, {@code static}, {@code final},
409 * {@code synchronized}, {@code native}, {@code strictfp}.
410 *
411 * @return a string describing this {@code Method}
412 *
413 * @jls 8.4.3 Method Modifiers
414 * @jls 9.4 Method Declarations
415 * @jls 9.6.1 Annotation Interface Elements
416 */
417 public String toString() {
418 return sharedToString(Modifier.methodModifiers(),
419 isDefault(),
420 parameterTypes,
421 exceptionTypes);
422 }
423
424 @Override
425 void specificToStringHeader(StringBuilder sb) {
426 sb.append(getReturnType().getTypeName()).append(' ');
427 sb.append(getDeclaringClassTypeName()).append('.');
428 sb.append(getName());
429 }
430
431 @Override
432 String toShortString() {
433 return "method " + getDeclaringClassTypeName() +
434 '.' + toShortSignature();
435 }
436
437 String toShortSignature() {
438 StringJoiner sj = new StringJoiner(",", getName() + "(", ")");
439 for (Class<?> parameterType : getSharedParameterTypes()) {
440 sj.add(parameterType.getTypeName());
441 }
442 return sj.toString();
443 }
444
445 /**
446 * Returns a string describing this {@code Method}, including type
447 * parameters. The string is formatted as the method access
448 * modifiers, if any, followed by an angle-bracketed
449 * comma-separated list of the method's type parameters, if any,
450 * including informative bounds of the type parameters, if any,
451 * followed by the method's generic return type, followed by a
452 * space, followed by the class declaring the method, followed by
453 * a period, followed by the method name, followed by a
454 * parenthesized, comma-separated list of the method's generic
455 * formal parameter types.
456 *
457 * If this method was declared to take a variable number of
458 * arguments, instead of denoting the last parameter as
459 * "<code><i>Type</i>[]</code>", it is denoted as
460 * "<code><i>Type</i>...</code>".
461 *
462 * A space is used to separate access modifiers from one another
463 * and from the type parameters or return type. If there are no
464 * type parameters, the type parameter list is elided; if the type
465 * parameter list is present, a space separates the list from the
466 * class name. If the method is declared to throw exceptions, the
467 * parameter list is followed by a space, followed by the word
468 * "{@code throws}" followed by a comma-separated list of the generic
469 * thrown exception types.
470 *
471 * <p>The access modifiers are placed in canonical order as
472 * specified by "The Java Language Specification". This is
473 * {@code public}, {@code protected} or {@code private} first,
474 * and then other modifiers in the following order:
475 * {@code abstract}, {@code default}, {@code static}, {@code final},
476 * {@code synchronized}, {@code native}, {@code strictfp}.
477 *
478 * @return a string describing this {@code Method},
479 * include type parameters
480 *
481 * @since 1.5
482 *
483 * @jls 8.4.3 Method Modifiers
484 * @jls 9.4 Method Declarations
485 * @jls 9.6.1 Annotation Interface Elements
486 */
487 @Override
488 public String toGenericString() {
489 return sharedToGenericString(Modifier.methodModifiers(), isDefault());
490 }
491
492 @Override
493 void specificToGenericStringHeader(StringBuilder sb) {
494 Type genRetType = getGenericReturnType();
495 sb.append(genRetType.getTypeName()).append(' ');
496 sb.append(getDeclaringClassTypeName()).append('.');
497 sb.append(getName());
498 }
499
500 /**
501 * Invokes the underlying method represented by this {@code Method}
502 * object, on the specified object with the specified parameters.
503 * Individual parameters are automatically unwrapped to match
504 * primitive formal parameters, and both primitive and reference
505 * parameters are subject to method invocation conversions as
506 * necessary.
507 *
508 * <p>If the underlying method is static, then the specified {@code obj}
509 * argument is ignored. It may be null.
510 *
511 * <p>If the number of formal parameters required by the underlying method is
512 * 0, the supplied {@code args} array may be of length 0 or null.
513 *
514 * <p>If the underlying method is an instance method, it is invoked
515 * using dynamic method lookup as documented in The Java Language
516 * Specification, section {@jls 15.12.4.4}; in particular,
517 * overriding based on the runtime type of the target object may occur.
518 *
519 * <p>If the underlying method is static, the class that declared
520 * the method is initialized if it has not already been initialized.
521 *
522 * <p>If the method completes normally, the value it returns is
523 * returned to the caller of invoke; if the value has a primitive
524 * type, it is first appropriately wrapped in an object. However,
525 * if the value has the type of an array of a primitive type, the
526 * elements of the array are <i>not</i> wrapped in objects; in
527 * other words, an array of primitive type is returned. If the
528 * underlying method return type is void, the invocation returns
529 * null.
530 *
531 * @param obj the object the underlying method is invoked from
532 * @param args the arguments used for the method call
533 * @return the result of dispatching the method represented by
534 * this object on {@code obj} with parameters
535 * {@code args}
536 *
537 * @throws IllegalAccessException if this {@code Method} object
538 * is enforcing Java language access control and the underlying
539 * method is inaccessible.
540 * @throws IllegalArgumentException if the method is an
541 * instance method and the specified object argument
542 * is not an instance of the class or interface
543 * declaring the underlying method (or of a subclass
544 * or implementor thereof); if the number of actual
545 * and formal parameters differ; if an unwrapping
546 * conversion for primitive arguments fails; or if,
547 * after possible unwrapping, a parameter value
548 * cannot be converted to the corresponding formal
549 * parameter type by a method invocation conversion.
550 * @throws InvocationTargetException if the underlying method
551 * throws an exception.
552 * @throws NullPointerException if the specified object is null
553 * and the method is an instance method.
554 * @throws ExceptionInInitializerError if the initialization
555 * provoked by this method fails.
556 */
557 @CallerSensitive
558 @ForceInline // to ensure Reflection.getCallerClass optimization
559 @IntrinsicCandidate
560 public Object invoke(Object obj, Object... args)
561 throws IllegalAccessException, InvocationTargetException
562 {
563 boolean callerSensitive = isCallerSensitive();
564 Class<?> caller = null;
565 if (!override || callerSensitive) {
566 caller = Reflection.getCallerClass();
567 }
568
569 // Reflection::getCallerClass filters all subclasses of
570 // jdk.internal.reflect.MethodAccessorImpl and Method::invoke(Object, Object[])
571 // Should not call Method::invoke(Object, Object[], Class) here
572 if (!override) {
573 checkAccess(caller, clazz,
574 Modifier.isStatic(modifiers) ? null : obj.getClass(),
575 modifiers);
576 }
577 MethodAccessor ma = methodAccessor; // read @Stable
578 if (ma == null) {
579 ma = acquireMethodAccessor();
580 }
581
582 return callerSensitive ? ma.invoke(obj, args, caller) : ma.invoke(obj, args);
583 }
584
585 /**
586 * This is to support MethodHandle calling caller-sensitive Method::invoke
587 * that may invoke a caller-sensitive method in order to get the original caller
588 * class (not the injected invoker).
589 *
590 * If this adapter is not presented, MethodHandle invoking Method::invoke
591 * will get an invoker class, a hidden nestmate of the original caller class,
592 * that becomes the caller class invoking Method::invoke.
593 */
594 @CallerSensitiveAdapter
595 private Object invoke(Object obj, Object[] args, Class<?> caller)
596 throws IllegalAccessException, InvocationTargetException
597 {
598 boolean callerSensitive = isCallerSensitive();
599 if (!override) {
600 checkAccess(caller, clazz,
601 Modifier.isStatic(modifiers) ? null : obj.getClass(),
602 modifiers);
603 }
604 MethodAccessor ma = methodAccessor; // read @Stable
605 if (ma == null) {
606 ma = acquireMethodAccessor();
607 }
608
609 return callerSensitive ? ma.invoke(obj, args, caller) : ma.invoke(obj, args);
610 }
611
612 // 0 = not initialized (@Stable contract)
613 // 1 = initialized, CS
614 // -1 = initialized, not CS
615 @Stable private byte callerSensitive;
616
617 private boolean isCallerSensitive() {
618 byte cs = callerSensitive;
619 if (cs == 0) {
620 callerSensitive = cs = (byte)(Reflection.isCallerSensitive(this) ? 1 : -1);
621 }
622 return (cs > 0);
623 }
624
625 /**
626 * {@return {@code true} if this method is a bridge
627 * method; returns {@code false} otherwise}
628 *
629 * @apiNote
630 * A bridge method is a {@linkplain isSynthetic synthetic} method
631 * created by a Java compiler alongside a method originating from
632 * the source code. Bridge methods are used by Java compilers in
633 * various circumstances to span differences in Java programming
634 * language semantics and JVM semantics.
635 *
636 * <p>One example use of bridge methods is as a technique for a
637 * Java compiler to support <i>covariant overrides</i>, where a
638 * subclass overrides a method and gives the new method a more
639 * specific return type than the method in the superclass. While
640 * the Java language specification forbids a class declaring two
641 * methods with the same parameter types but a different return
642 * type, the virtual machine does not. A common case where
643 * covariant overrides are used is for a {@link
644 * java.lang.Cloneable Cloneable} class where the {@link
645 * Object#clone() clone} method inherited from {@code
646 * java.lang.Object} is overridden and declared to return the type
647 * of the class. For example, {@code Object} declares
648 * <pre>{@code protected Object clone() throws CloneNotSupportedException {...}}</pre>
649 * and {@code EnumSet<E>} declares its language-level {@linkplain
650 * java.util.EnumSet#clone() covariant override}
651 * <pre>{@code public EnumSet<E> clone() {...}}</pre>
652 * If this technique was being used, the resulting class file for
653 * {@code EnumSet} would have two {@code clone} methods, one
654 * returning {@code EnumSet<E>} and the second a bridge method
655 * returning {@code Object}. The bridge method is a JVM-level
656 * override of {@code Object.clone()}. The body of the {@code
657 * clone} bridge method calls its non-bridge counterpart and
658 * returns its result.
659 * @since 1.5
660 *
661 * @jls 8.4.8.3 Requirements in Overriding and Hiding
662 * @jls 15.12.4.5 Create Frame, Synchronize, Transfer Control
663 * @jvms 4.6 Methods
664 * @see <a
665 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
666 * programming language and JVM modeling in core reflection</a>
667 */
668 public boolean isBridge() {
669 return (getModifiers() & Modifier.BRIDGE) != 0;
670 }
671
672 /**
673 * {@inheritDoc}
674 * @since 1.5
675 * @jls 8.4.1 Formal Parameters
676 */
677 @Override
678 public boolean isVarArgs() {
679 return super.isVarArgs();
680 }
681
682 /**
683 * {@inheritDoc}
684 * @jls 13.1 The Form of a Binary
685 * @jvms 4.6 Methods
686 * @see <a
687 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
688 * programming language and JVM modeling in core reflection</a>
689 * @since 1.5
690 */
691 @Override
692 public boolean isSynthetic() {
693 return super.isSynthetic();
694 }
695
696 /**
697 * Returns {@code true} if this method is a default
698 * method; returns {@code false} otherwise.
699 *
700 * A default method is a public non-abstract instance method, that
701 * is, a non-static method with a body, declared in an interface.
702 *
703 * @return true if and only if this method is a default
704 * method as defined by the Java Language Specification.
705 * @since 1.8
706 * @jls 9.4 Method Declarations
707 */
708 public boolean isDefault() {
709 // Default methods are public non-abstract instance methods
710 // declared in an interface.
711 return ((getModifiers() & (Modifier.ABSTRACT | Modifier.PUBLIC | Modifier.STATIC)) ==
712 Modifier.PUBLIC) && getDeclaringClass().isInterface();
713 }
714
715 // NOTE that there is no synchronization used here. It is correct
716 // (though not efficient) to generate more than one MethodAccessor
717 // for a given Method. However, avoiding synchronization will
718 // probably make the implementation more scalable.
719 private MethodAccessor acquireMethodAccessor() {
720 // First check to see if one has been created yet, and take it
721 // if so
722 Method root = this.root;
723 MethodAccessor tmp = root == null ? null : root.getMethodAccessor();
724 if (tmp != null) {
725 methodAccessor = tmp;
726 } else {
727 // Otherwise fabricate one and propagate it up to the root
728 tmp = reflectionFactory.newMethodAccessor(this, isCallerSensitive());
729 // set the method accessor only if it's not using native implementation
730 if (VM.isJavaLangInvokeInited())
731 setMethodAccessor(tmp);
732 }
733
734 return tmp;
735 }
736
737 // Returns MethodAccessor for this Method object, not looking up
738 // the chain to the root
739 MethodAccessor getMethodAccessor() {
740 return methodAccessor;
741 }
742
743 // Sets the MethodAccessor for this Method object and
744 // (recursively) its root
745 void setMethodAccessor(MethodAccessor accessor) {
746 methodAccessor = accessor;
747 // Propagate up
748 Method root = this.root;
749 if (root != null) {
750 root.setMethodAccessor(accessor);
751 }
752 }
753
754 /**
755 * Returns the default value for the annotation member represented by
756 * this {@code Method} instance. If the member is of a primitive type,
757 * an instance of the corresponding wrapper type is returned. Returns
758 * null if no default is associated with the member, or if the method
759 * instance does not represent a declared member of an annotation type.
760 *
761 * @return the default value for the annotation member represented
762 * by this {@code Method} instance.
763 * @throws TypeNotPresentException if the annotation is of type
764 * {@link Class} and no definition can be found for the
765 * default class value.
766 * @since 1.5
767 * @jls 9.6.2 Defaults for Annotation Type Elements
768 */
769 public Object getDefaultValue() {
770 if (annotationDefault == null)
771 return null;
772 Class<?> memberType = AnnotationType.invocationHandlerReturnType(
773 getReturnType());
774 Object result = AnnotationParser.parseMemberValue(
775 memberType, ByteBuffer.wrap(annotationDefault),
776 SharedSecrets.getJavaLangAccess().
777 getConstantPool(getDeclaringClass()),
778 getDeclaringClass());
779 if (result instanceof ExceptionProxy) {
780 if (result instanceof TypeNotPresentExceptionProxy proxy) {
781 throw new TypeNotPresentException(proxy.typeName(), proxy.getCause());
782 }
783 throw new AnnotationFormatError("Invalid default: " + this);
784 }
785 return result;
786 }
787
788 /**
789 * {@inheritDoc}
790 * @throws NullPointerException {@inheritDoc}
791 * @since 1.5
792 */
793 @Override
794 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
795 return super.getAnnotation(annotationClass);
796 }
797
798 /**
799 * {@inheritDoc}
800 * @since 1.5
801 */
802 @Override
803 public Annotation[] getDeclaredAnnotations() {
804 return super.getDeclaredAnnotations();
805 }
806
807 /**
808 * {@inheritDoc}
809 * @since 1.5
810 */
811 @Override
812 public Annotation[][] getParameterAnnotations() {
813 return sharedGetParameterAnnotations(parameterTypes, parameterAnnotations);
814 }
815
816 /**
817 * {@inheritDoc}
818 * @since 1.8
819 */
820 @Override
821 public AnnotatedType getAnnotatedReturnType() {
822 return getAnnotatedReturnType0(getGenericReturnType());
823 }
824
825 @Override
826 boolean handleParameterNumberMismatch(int resultLength, Class<?>[] parameterTypes) {
827 throw new AnnotationFormatError("Parameter annotations don't match number of parameters");
828 }
829 }