1 /*
2 * Copyright (c) 1996, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.reflect;
27
28 import jdk.internal.access.SharedSecrets;
29 import jdk.internal.misc.VM;
30 import jdk.internal.reflect.CallerSensitive;
31 import jdk.internal.reflect.CallerSensitiveAdapter;
32 import jdk.internal.reflect.MethodAccessor;
33 import jdk.internal.reflect.Reflection;
34 import jdk.internal.vm.annotation.ForceInline;
35 import jdk.internal.vm.annotation.IntrinsicCandidate;
36 import jdk.internal.vm.annotation.Stable;
37 import sun.reflect.annotation.ExceptionProxy;
38 import sun.reflect.annotation.TypeNotPresentExceptionProxy;
39 import sun.reflect.generics.repository.GenericDeclRepository;
40 import sun.reflect.generics.repository.MethodRepository;
41 import sun.reflect.generics.factory.CoreReflectionFactory;
42 import sun.reflect.generics.factory.GenericsFactory;
43 import sun.reflect.generics.scope.MethodScope;
44 import sun.reflect.annotation.AnnotationType;
45 import sun.reflect.annotation.AnnotationParser;
46 import java.lang.annotation.Annotation;
47 import java.lang.annotation.AnnotationFormatError;
48 import java.nio.ByteBuffer;
49 import java.util.Optional;
50 import java.util.StringJoiner;
51 import java.util.function.Function;
52
53 /**
54 * A {@code Method} provides information about, and access to, a single method
55 * on a class or interface. The reflected method may be a class method
56 * or an instance method (including an abstract method).
57 *
58 * <p>A {@code Method} permits widening conversions to occur when matching the
59 * actual parameters to invoke with the underlying method's formal
60 * parameters, but it throws an {@code IllegalArgumentException} if a
61 * narrowing conversion would occur.
62 *
63 * @see Member
64 * @see java.lang.Class
65 * @see java.lang.Class#getMethods()
66 * @see java.lang.Class#getMethod(String, Class[])
67 * @see java.lang.Class#getDeclaredMethods()
68 * @see java.lang.Class#getDeclaredMethod(String, Class[])
69 *
70 * @author Kenneth Russell
71 * @author Nakul Saraiya
72 * @since 1.1
73 */
74 public final class Method extends Executable {
75 private final Class<?> clazz;
76 private final int slot;
77 // This is guaranteed to be interned by the VM in the 1.4
78 // reflection implementation
79 private final String name;
80 private final Class<?> returnType;
81 private final Class<?>[] parameterTypes;
82 private final Class<?>[] exceptionTypes;
83 private final int modifiers;
84 // Generics and annotations support
85 private final transient String signature;
86 private final byte[] annotations;
87 private final byte[] parameterAnnotations;
88 private final byte[] annotationDefault;
89
90 /**
91 * Methods are mutable due to {@link AccessibleObject#setAccessible(boolean)}.
92 * Thus, we return a new copy of a root each time a method is returned.
93 * Some lazily initialized immutable states can be stored on root and shared to the copies.
94 */
95 private Method root;
96 private transient volatile MethodRepository genericInfo;
97 private @Stable MethodAccessor methodAccessor;
98 // End shared states
99 private int hash; // not shared right now, eligible if expensive
100
101 private volatile Optional<?> codeModel;
102
103 // Generics infrastructure
104 private String getGenericSignature() {return signature;}
105
106 // Accessor for factory
107 private GenericsFactory getFactory() {
108 // create scope and factory
109 return CoreReflectionFactory.make(this, MethodScope.make(this));
110 }
111
112 // Accessor for generic info repository
113 @Override
114 MethodRepository getGenericInfo() {
115 var genericInfo = this.genericInfo;
116 if (genericInfo == null) {
117 var root = this.root;
118 if (root != null) {
119 genericInfo = root.getGenericInfo();
120 } else {
121 genericInfo = MethodRepository.make(getGenericSignature(), getFactory());
122 }
123 this.genericInfo = genericInfo;
124 }
125 return genericInfo;
126 }
127
128 /**
129 * Package-private constructor
130 */
131 Method(Class<?> declaringClass,
132 String name,
133 Class<?>[] parameterTypes,
134 Class<?> returnType,
135 Class<?>[] checkedExceptions,
136 int modifiers,
137 int slot,
138 String signature,
139 byte[] annotations,
140 byte[] parameterAnnotations,
141 byte[] annotationDefault) {
142 this.clazz = declaringClass;
143 this.name = name;
144 this.parameterTypes = parameterTypes;
145 this.returnType = returnType;
146 this.exceptionTypes = checkedExceptions;
147 this.modifiers = modifiers;
148 this.slot = slot;
149 this.signature = signature;
150 this.annotations = annotations;
151 this.parameterAnnotations = parameterAnnotations;
152 this.annotationDefault = annotationDefault;
153 }
154
155 /**
156 * Package-private routine (exposed to java.lang.Class via
157 * ReflectAccess) which returns a copy of this Method. The copy's
158 * "root" field points to this Method.
159 */
160 Method copy() {
161 if (this.root != null)
162 throw new IllegalArgumentException("Can not copy a non-root Method");
163
164 Method res = new Method(clazz, name, parameterTypes, returnType,
165 exceptionTypes, modifiers, slot, signature,
166 annotations, parameterAnnotations, annotationDefault);
167 res.root = this;
168 // Propagate shared states
169 res.methodAccessor = methodAccessor;
170 res.genericInfo = genericInfo;
171 return res;
172 }
173
174 /**
175 * @throws InaccessibleObjectException {@inheritDoc}
176 */
177 @Override
178 @CallerSensitive
179 public void setAccessible(boolean flag) {
180 if (flag) checkCanSetAccessible(Reflection.getCallerClass());
181 setAccessible0(flag);
182 }
183
184 @Override
185 void checkCanSetAccessible(Class<?> caller) {
186 checkCanSetAccessible(caller, clazz);
187 }
188
189 @Override
190 Method getRoot() {
191 return root;
192 }
193
194 @Override
195 boolean hasGenericInformation() {
196 return (getGenericSignature() != null);
197 }
198
199 @Override
200 byte[] getAnnotationBytes() {
201 return annotations;
202 }
203
204 /**
205 * Returns the {@code Class} object representing the class or interface
206 * that declares the method represented by this object.
207 */
208 @Override
209 public Class<?> getDeclaringClass() {
210 return clazz;
211 }
212
213 /**
214 * Returns the name of the method represented by this {@code Method}
215 * object, as a {@code String}.
216 */
217 @Override
218 public String getName() {
219 return name;
220 }
221
222 /**
223 * {@inheritDoc}
224 * @jls 8.4.3 Method Modifiers
225 */
226 @Override
227 public int getModifiers() {
228 return modifiers;
229 }
230
231 /* package */
232 Optional<?> setCodeModelIfNeeded(Function<Method, Optional<?>> modelFactory) {
233 Optional<?> localRef = codeModel;
234 if (localRef == null) {
235 synchronized (this) {
236 localRef = codeModel;
237 if (localRef == null) {
238 Optional<?> op = modelFactory.apply(this);
239 codeModel = localRef = op;
240 }
241 }
242 }
243 return localRef;
244 }
245
246 /**
247 * {@inheritDoc}
248 * @throws GenericSignatureFormatError {@inheritDoc}
249 * @since 1.5
250 * @jls 8.4.4 Generic Methods
251 */
252 @Override
253 @SuppressWarnings("unchecked")
254 public TypeVariable<Method>[] getTypeParameters() {
255 if (getGenericSignature() != null)
256 return (TypeVariable<Method>[])getGenericInfo().getTypeParameters();
257 else
258 return (TypeVariable<Method>[])GenericDeclRepository.EMPTY_TYPE_VARS;
259 }
260
261 /**
262 * Returns a {@code Class} object that represents the formal return type
263 * of the method represented by this {@code Method} object.
264 *
265 * @return the return type for the method this object represents
266 */
267 public Class<?> getReturnType() {
268 return returnType;
269 }
270
271 /**
272 * Returns a {@code Type} object that represents the formal return
273 * type of the method represented by this {@code Method} object.
274 *
275 * <p>If the return type is a parameterized type,
276 * the {@code Type} object returned must accurately reflect
277 * the actual type arguments used in the source code.
278 *
279 * <p>If the return type is a type variable or a parameterized type, it
280 * is created. Otherwise, it is resolved.
281 *
282 * @return a {@code Type} object that represents the formal return
283 * type of the underlying method
284 * @throws GenericSignatureFormatError
285 * if the generic method signature does not conform to the format
286 * specified in
287 * <cite>The Java Virtual Machine Specification</cite>
288 * @throws TypeNotPresentException if the underlying method's
289 * return type refers to a non-existent class or interface declaration
290 * @throws MalformedParameterizedTypeException if the
291 * underlying method's return type refers to a parameterized
292 * type that cannot be instantiated for any reason
293 * @since 1.5
294 */
295 public Type getGenericReturnType() {
296 if (getGenericSignature() != null) {
297 return getGenericInfo().getReturnType();
298 } else { return getReturnType();}
299 }
300
301 @Override
302 Class<?>[] getSharedParameterTypes() {
303 return parameterTypes;
304 }
305
306 @Override
307 Class<?>[] getSharedExceptionTypes() {
308 return exceptionTypes;
309 }
310
311 /**
312 * {@inheritDoc}
313 */
314 @Override
315 public Class<?>[] getParameterTypes() {
316 return parameterTypes.length == 0 ? parameterTypes: parameterTypes.clone();
317 }
318
319 /**
320 * {@inheritDoc}
321 * @since 1.8
322 */
323 public int getParameterCount() { return parameterTypes.length; }
324
325
326 /**
327 * {@inheritDoc}
328 * @throws GenericSignatureFormatError {@inheritDoc}
329 * @throws TypeNotPresentException {@inheritDoc}
330 * @throws MalformedParameterizedTypeException {@inheritDoc}
331 * @since 1.5
332 */
333 @Override
334 public Type[] getGenericParameterTypes() {
335 return super.getGenericParameterTypes();
336 }
337
338 /**
339 * {@inheritDoc}
340 */
341 @Override
342 public Class<?>[] getExceptionTypes() {
343 return exceptionTypes.length == 0 ? exceptionTypes : exceptionTypes.clone();
344 }
345
346 /**
347 * {@inheritDoc}
348 * @throws GenericSignatureFormatError {@inheritDoc}
349 * @throws TypeNotPresentException {@inheritDoc}
350 * @throws MalformedParameterizedTypeException {@inheritDoc}
351 * @since 1.5
352 */
353 @Override
354 public Type[] getGenericExceptionTypes() {
355 return super.getGenericExceptionTypes();
356 }
357
358 /**
359 * Compares this {@code Method} against the specified object. Returns
360 * true if the objects are the same. Two {@code Methods} are the same if
361 * they were declared by the same class and have the same name
362 * and formal parameter types and return type.
363 */
364 public boolean equals(Object obj) {
365 if (obj instanceof Method other) {
366 if ((getDeclaringClass() == other.getDeclaringClass())
367 && (getName() == other.getName())) {
368 if (!returnType.equals(other.getReturnType()))
369 return false;
370 return equalParamTypes(parameterTypes, other.parameterTypes);
371 }
372 }
373 return false;
374 }
375
376 /**
377 * Returns a hashcode for this {@code Method}. The hashcode is computed
378 * as the exclusive-or of the hashcodes for the underlying
379 * method's declaring class name and the method's name.
380 */
381 public int hashCode() {
382 int hc = hash;
383
384 if (hc == 0) {
385 hc = hash = getDeclaringClass().getName().hashCode() ^ getName()
386 .hashCode();
387 }
388 return hc;
389 }
390
391 /**
392 * Returns a string describing this {@code Method}. The string is
393 * formatted as the method access modifiers, if any, followed by
394 * the method return type, followed by a space, followed by the
395 * class declaring the method, followed by a period, followed by
396 * the method name, followed by a parenthesized, comma-separated
397 * list of the method's formal parameter types. If the method
398 * throws checked exceptions, the parameter list is followed by a
399 * space, followed by the word "{@code throws}" followed by a
400 * comma-separated list of the thrown exception types.
401 * For example:
402 * <pre>
403 * public boolean java.lang.Object.equals(java.lang.Object)
404 * </pre>
405 *
406 * <p>The access modifiers are placed in canonical order as
407 * specified by "The Java Language Specification". This is
408 * {@code public}, {@code protected} or {@code private} first,
409 * and then other modifiers in the following order:
410 * {@code abstract}, {@code default}, {@code static}, {@code final},
411 * {@code synchronized}, {@code native}, {@code strictfp}.
412 *
413 * @return a string describing this {@code Method}
414 *
415 * @jls 8.4.3 Method Modifiers
416 * @jls 9.4 Method Declarations
417 * @jls 9.6.1 Annotation Interface Elements
418 */
419 public String toString() {
420 return sharedToString(Modifier.methodModifiers(),
421 isDefault(),
422 parameterTypes,
423 exceptionTypes);
424 }
425
426 @Override
427 void specificToStringHeader(StringBuilder sb) {
428 sb.append(getReturnType().getTypeName()).append(' ');
429 sb.append(getDeclaringClass().getTypeName()).append('.');
430 sb.append(getName());
431 }
432
433 @Override
434 String toShortString() {
435 return "method " + getDeclaringClass().getTypeName() +
436 '.' + toShortSignature();
437 }
438
439 String toShortSignature() {
440 StringJoiner sj = new StringJoiner(",", getName() + "(", ")");
441 for (Class<?> parameterType : getSharedParameterTypes()) {
442 sj.add(parameterType.getTypeName());
443 }
444 return sj.toString();
445 }
446
447 /**
448 * Returns a string describing this {@code Method}, including type
449 * parameters. The string is formatted as the method access
450 * modifiers, if any, followed by an angle-bracketed
451 * comma-separated list of the method's type parameters, if any,
452 * including informative bounds of the type parameters, if any,
453 * followed by the method's generic return type, followed by a
454 * space, followed by the class declaring the method, followed by
455 * a period, followed by the method name, followed by a
456 * parenthesized, comma-separated list of the method's generic
457 * formal parameter types.
458 *
459 * If this method was declared to take a variable number of
460 * arguments, instead of denoting the last parameter as
461 * "<code><i>Type</i>[]</code>", it is denoted as
462 * "<code><i>Type</i>...</code>".
463 *
464 * A space is used to separate access modifiers from one another
465 * and from the type parameters or return type. If there are no
466 * type parameters, the type parameter list is elided; if the type
467 * parameter list is present, a space separates the list from the
468 * class name. If the method is declared to throw exceptions, the
469 * parameter list is followed by a space, followed by the word
470 * "{@code throws}" followed by a comma-separated list of the generic
471 * thrown exception types.
472 *
473 * <p>The access modifiers are placed in canonical order as
474 * specified by "The Java Language Specification". This is
475 * {@code public}, {@code protected} or {@code private} first,
476 * and then other modifiers in the following order:
477 * {@code abstract}, {@code default}, {@code static}, {@code final},
478 * {@code synchronized}, {@code native}, {@code strictfp}.
479 *
480 * @return a string describing this {@code Method},
481 * include type parameters
482 *
483 * @since 1.5
484 *
485 * @jls 8.4.3 Method Modifiers
486 * @jls 9.4 Method Declarations
487 * @jls 9.6.1 Annotation Interface Elements
488 */
489 @Override
490 public String toGenericString() {
491 return sharedToGenericString(Modifier.methodModifiers(), isDefault());
492 }
493
494 @Override
495 void specificToGenericStringHeader(StringBuilder sb) {
496 Type genRetType = getGenericReturnType();
497 sb.append(genRetType.getTypeName()).append(' ');
498 sb.append(getDeclaringClass().getTypeName()).append('.');
499 sb.append(getName());
500 }
501
502 /**
503 * Invokes the underlying method represented by this {@code Method}
504 * object, on the specified object with the specified parameters.
505 * Individual parameters are automatically unwrapped to match
506 * primitive formal parameters, and both primitive and reference
507 * parameters are subject to method invocation conversions as
508 * necessary.
509 *
510 * <p>If the underlying method is static, then the specified {@code obj}
511 * argument is ignored. It may be null.
512 *
513 * <p>If the number of formal parameters required by the underlying method is
514 * 0, the supplied {@code args} array may be of length 0 or null.
515 *
516 * <p>If the underlying method is an instance method, it is invoked
517 * using dynamic method lookup as documented in The Java Language
518 * Specification, section {@jls 15.12.4.4}; in particular,
519 * overriding based on the runtime type of the target object may occur.
520 *
521 * <p>If the underlying method is static, the class that declared
522 * the method is initialized if it has not already been initialized.
523 *
524 * <p>If the method completes normally, the value it returns is
525 * returned to the caller of invoke; if the value has a primitive
526 * type, it is first appropriately wrapped in an object. However,
527 * if the value has the type of an array of a primitive type, the
528 * elements of the array are <i>not</i> wrapped in objects; in
529 * other words, an array of primitive type is returned. If the
530 * underlying method return type is void, the invocation returns
531 * null.
532 *
533 * @param obj the object the underlying method is invoked from
534 * @param args the arguments used for the method call
535 * @return the result of dispatching the method represented by
536 * this object on {@code obj} with parameters
537 * {@code args}
538 *
539 * @throws IllegalAccessException if this {@code Method} object
540 * is enforcing Java language access control and the underlying
541 * method is inaccessible.
542 * @throws IllegalArgumentException if the method is an
543 * instance method and the specified object argument
544 * is not an instance of the class or interface
545 * declaring the underlying method (or of a subclass
546 * or implementor thereof); if the number of actual
547 * and formal parameters differ; if an unwrapping
548 * conversion for primitive arguments fails; or if,
549 * after possible unwrapping, a parameter value
550 * cannot be converted to the corresponding formal
551 * parameter type by a method invocation conversion.
552 * @throws InvocationTargetException if the underlying method
553 * throws an exception.
554 * @throws NullPointerException if the specified object is null
555 * and the method is an instance method.
556 * @throws ExceptionInInitializerError if the initialization
557 * provoked by this method fails.
558 */
559 @CallerSensitive
560 @ForceInline // to ensure Reflection.getCallerClass optimization
561 @IntrinsicCandidate
562 public Object invoke(Object obj, Object... args)
563 throws IllegalAccessException, InvocationTargetException
564 {
565 boolean callerSensitive = isCallerSensitive();
566 Class<?> caller = null;
567 if (!override || callerSensitive) {
568 caller = Reflection.getCallerClass();
569 }
570
571 // Reflection::getCallerClass filters all subclasses of
572 // jdk.internal.reflect.MethodAccessorImpl and Method::invoke(Object, Object[])
573 // Should not call Method::invoke(Object, Object[], Class) here
574 if (!override) {
575 checkAccess(caller, clazz,
576 Modifier.isStatic(modifiers) ? null : obj.getClass(),
577 modifiers);
578 }
579 MethodAccessor ma = methodAccessor; // read @Stable
580 if (ma == null) {
581 ma = acquireMethodAccessor();
582 }
583
584 return callerSensitive ? ma.invoke(obj, args, caller) : ma.invoke(obj, args);
585 }
586
587 /**
588 * This is to support MethodHandle calling caller-sensitive Method::invoke
589 * that may invoke a caller-sensitive method in order to get the original caller
590 * class (not the injected invoker).
591 *
592 * If this adapter is not presented, MethodHandle invoking Method::invoke
593 * will get an invoker class, a hidden nestmate of the original caller class,
594 * that becomes the caller class invoking Method::invoke.
595 */
596 @CallerSensitiveAdapter
597 private Object invoke(Object obj, Object[] args, Class<?> caller)
598 throws IllegalAccessException, InvocationTargetException
599 {
600 boolean callerSensitive = isCallerSensitive();
601 if (!override) {
602 checkAccess(caller, clazz,
603 Modifier.isStatic(modifiers) ? null : obj.getClass(),
604 modifiers);
605 }
606 MethodAccessor ma = methodAccessor; // read @Stable
607 if (ma == null) {
608 ma = acquireMethodAccessor();
609 }
610
611 return callerSensitive ? ma.invoke(obj, args, caller) : ma.invoke(obj, args);
612 }
613
614 // 0 = not initialized (@Stable contract)
615 // 1 = initialized, CS
616 // -1 = initialized, not CS
617 @Stable private byte callerSensitive;
618
619 private boolean isCallerSensitive() {
620 byte cs = callerSensitive;
621 if (cs == 0) {
622 callerSensitive = cs = (byte)(Reflection.isCallerSensitive(this) ? 1 : -1);
623 }
624 return (cs > 0);
625 }
626
627 /**
628 * {@return {@code true} if this method is a bridge
629 * method; returns {@code false} otherwise}
630 *
631 * @apiNote
632 * A bridge method is a {@linkplain isSynthetic synthetic} method
633 * created by a Java compiler alongside a method originating from
634 * the source code. Bridge methods are used by Java compilers in
635 * various circumstances to span differences in Java programming
636 * language semantics and JVM semantics.
637 *
638 * <p>One example use of bridge methods is as a technique for a
639 * Java compiler to support <i>covariant overrides</i>, where a
640 * subclass overrides a method and gives the new method a more
641 * specific return type than the method in the superclass. While
642 * the Java language specification forbids a class declaring two
643 * methods with the same parameter types but a different return
644 * type, the virtual machine does not. A common case where
645 * covariant overrides are used is for a {@link
646 * java.lang.Cloneable Cloneable} class where the {@link
647 * Object#clone() clone} method inherited from {@code
648 * java.lang.Object} is overridden and declared to return the type
649 * of the class. For example, {@code Object} declares
650 * <pre>{@code protected Object clone() throws CloneNotSupportedException {...}}</pre>
651 * and {@code EnumSet<E>} declares its language-level {@linkplain
652 * java.util.EnumSet#clone() covariant override}
653 * <pre>{@code public EnumSet<E> clone() {...}}</pre>
654 * If this technique was being used, the resulting class file for
655 * {@code EnumSet} would have two {@code clone} methods, one
656 * returning {@code EnumSet<E>} and the second a bridge method
657 * returning {@code Object}. The bridge method is a JVM-level
658 * override of {@code Object.clone()}. The body of the {@code
659 * clone} bridge method calls its non-bridge counterpart and
660 * returns its result.
661 * @since 1.5
662 *
663 * @jls 8.4.8.3 Requirements in Overriding and Hiding
664 * @jls 15.12.4.5 Create Frame, Synchronize, Transfer Control
665 * @jvms 4.6 Methods
666 * @see <a
667 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
668 * programming language and JVM modeling in core reflection</a>
669 */
670 public boolean isBridge() {
671 return (getModifiers() & Modifier.BRIDGE) != 0;
672 }
673
674 /**
675 * {@inheritDoc}
676 * @since 1.5
677 * @jls 8.4.1 Formal Parameters
678 */
679 @Override
680 public boolean isVarArgs() {
681 return super.isVarArgs();
682 }
683
684 /**
685 * {@inheritDoc}
686 * @jls 13.1 The Form of a Binary
687 * @jvms 4.6 Methods
688 * @see <a
689 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
690 * programming language and JVM modeling in core reflection</a>
691 * @since 1.5
692 */
693 @Override
694 public boolean isSynthetic() {
695 return super.isSynthetic();
696 }
697
698 /**
699 * Returns {@code true} if this method is a default
700 * method; returns {@code false} otherwise.
701 *
702 * A default method is a public non-abstract instance method, that
703 * is, a non-static method with a body, declared in an interface.
704 *
705 * @return true if and only if this method is a default
706 * method as defined by the Java Language Specification.
707 * @since 1.8
708 * @jls 9.4 Method Declarations
709 */
710 public boolean isDefault() {
711 // Default methods are public non-abstract instance methods
712 // declared in an interface.
713 return ((getModifiers() & (Modifier.ABSTRACT | Modifier.PUBLIC | Modifier.STATIC)) ==
714 Modifier.PUBLIC) && getDeclaringClass().isInterface();
715 }
716
717 // NOTE that there is no synchronization used here. It is correct
718 // (though not efficient) to generate more than one MethodAccessor
719 // for a given Method. However, avoiding synchronization will
720 // probably make the implementation more scalable.
721 private MethodAccessor acquireMethodAccessor() {
722 // First check to see if one has been created yet, and take it
723 // if so
724 Method root = this.root;
725 MethodAccessor tmp = root == null ? null : root.getMethodAccessor();
726 if (tmp != null) {
727 methodAccessor = tmp;
728 } else {
729 // Otherwise fabricate one and propagate it up to the root
730 tmp = reflectionFactory.newMethodAccessor(this, isCallerSensitive());
731 // set the method accessor only if it's not using native implementation
732 if (VM.isJavaLangInvokeInited())
733 setMethodAccessor(tmp);
734 }
735
736 return tmp;
737 }
738
739 // Returns MethodAccessor for this Method object, not looking up
740 // the chain to the root
741 MethodAccessor getMethodAccessor() {
742 return methodAccessor;
743 }
744
745 // Sets the MethodAccessor for this Method object and
746 // (recursively) its root
747 void setMethodAccessor(MethodAccessor accessor) {
748 methodAccessor = accessor;
749 // Propagate up
750 Method root = this.root;
751 if (root != null) {
752 root.setMethodAccessor(accessor);
753 }
754 }
755
756 /**
757 * Returns the default value for the annotation member represented by
758 * this {@code Method} instance. If the member is of a primitive type,
759 * an instance of the corresponding wrapper type is returned. Returns
760 * null if no default is associated with the member, or if the method
761 * instance does not represent a declared member of an annotation type.
762 *
763 * @return the default value for the annotation member represented
764 * by this {@code Method} instance.
765 * @throws TypeNotPresentException if the annotation is of type
766 * {@link Class} and no definition can be found for the
767 * default class value.
768 * @since 1.5
769 * @jls 9.6.2 Defaults for Annotation Interface Elements
770 */
771 public Object getDefaultValue() {
772 if (annotationDefault == null)
773 return null;
774 Class<?> memberType = AnnotationType.invocationHandlerReturnType(
775 getReturnType());
776 Object result = AnnotationParser.parseMemberValue(
777 memberType, ByteBuffer.wrap(annotationDefault),
778 SharedSecrets.getJavaLangAccess().
779 getConstantPool(getDeclaringClass()),
780 getDeclaringClass());
781 if (result instanceof ExceptionProxy) {
782 if (result instanceof TypeNotPresentExceptionProxy proxy) {
783 throw new TypeNotPresentException(proxy.typeName(), proxy.getCause());
784 }
785 throw new AnnotationFormatError("Invalid default: " + this);
786 }
787 return result;
788 }
789
790 /**
791 * {@inheritDoc}
792 * @throws NullPointerException {@inheritDoc}
793 * @since 1.5
794 */
795 @Override
796 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
797 return super.getAnnotation(annotationClass);
798 }
799
800 /**
801 * {@inheritDoc}
802 * @since 1.5
803 */
804 @Override
805 public Annotation[] getDeclaredAnnotations() {
806 return super.getDeclaredAnnotations();
807 }
808
809 /**
810 * {@inheritDoc}
811 * @since 1.5
812 */
813 @Override
814 public Annotation[][] getParameterAnnotations() {
815 return sharedGetParameterAnnotations(parameterTypes, parameterAnnotations);
816 }
817
818 /**
819 * {@inheritDoc}
820 * @since 1.8
821 */
822 @Override
823 public AnnotatedType getAnnotatedReturnType() {
824 return getAnnotatedReturnType0(getGenericReturnType());
825 }
826
827 @Override
828 boolean handleParameterNumberMismatch(int resultLength, Class<?>[] parameterTypes) {
829 throw new AnnotationFormatError("Parameter annotations don't match number of parameters");
830 }
831 }