1 /*
2 * Copyright (c) 1996, 2022, 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 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 // lazily initialize repository if necessary
113 if (genericInfo == null) {
114 // create and cache generic info repository
115 genericInfo = MethodRepository.make(getGenericSignature(),
116 getFactory());
117 }
118 return genericInfo; //return cached repository
119 }
120
121 /**
122 * Package-private constructor
123 */
124 Method(Class<?> declaringClass,
125 String name,
126 Class<?>[] parameterTypes,
127 Class<?> returnType,
128 Class<?>[] checkedExceptions,
129 int modifiers,
130 int slot,
131 String signature,
132 byte[] annotations,
133 byte[] parameterAnnotations,
134 byte[] annotationDefault) {
135 assert PrimitiveClass.isPrimaryType(declaringClass);
136 this.clazz = declaringClass;
137 this.name = name;
138 this.parameterTypes = parameterTypes;
139 this.returnType = returnType;
140 this.exceptionTypes = checkedExceptions;
141 this.modifiers = modifiers;
142 this.slot = slot;
143 this.signature = signature;
144 this.annotations = annotations;
145 this.parameterAnnotations = parameterAnnotations;
146 this.annotationDefault = annotationDefault;
147 }
148
149 /**
150 * Package-private routine (exposed to java.lang.Class via
151 * ReflectAccess) which returns a copy of this Method. The copy's
152 * "root" field points to this Method.
153 */
154 Method copy() {
155 // This routine enables sharing of MethodAccessor objects
156 // among Method objects which refer to the same underlying
157 // method in the VM. (All of this contortion is only necessary
158 // because of the "accessibility" bit in AccessibleObject,
159 // which implicitly requires that new java.lang.reflect
160 // objects be fabricated for each reflective call on Class
161 // objects.)
162 if (this.root != null)
163 throw new IllegalArgumentException("Can not copy a non-root Method");
164
165 Method res = new Method(clazz, name, parameterTypes, returnType,
166 exceptionTypes, modifiers, slot, signature,
167 annotations, parameterAnnotations, annotationDefault);
168 res.root = this;
169 // Might as well eagerly propagate this if already present
170 res.methodAccessor = methodAccessor;
171 return res;
172 }
173
174 /**
175 * Make a copy of a leaf method.
176 */
177 Method leafCopy() {
178 if (this.root == null)
179 throw new IllegalArgumentException("Can only leafCopy a non-root Method");
180
181 Method res = new Method(clazz, name, parameterTypes, returnType,
182 exceptionTypes, modifiers, slot, signature,
183 annotations, parameterAnnotations, annotationDefault);
184 res.root = root;
185 res.methodAccessor = methodAccessor;
186 return res;
187 }
188
189 /**
190 * @throws InaccessibleObjectException {@inheritDoc}
191 * @throws SecurityException {@inheritDoc}
192 */
193 @Override
194 @CallerSensitive
195 public void setAccessible(boolean flag) {
196 AccessibleObject.checkPermission();
197 if (flag) checkCanSetAccessible(Reflection.getCallerClass());
198 setAccessible0(flag);
199 }
200
201 @Override
202 void checkCanSetAccessible(Class<?> caller) {
203 checkCanSetAccessible(caller, clazz);
204 }
205
206 @Override
207 Method getRoot() {
208 return root;
209 }
210
211 @Override
212 boolean hasGenericInformation() {
213 return (getGenericSignature() != null);
214 }
215
216 @Override
217 byte[] getAnnotationBytes() {
218 return annotations;
219 }
220
221 /**
222 * Returns the {@code Class} object representing the class or interface
223 * that declares the method represented by this object.
224 */
225 @Override
226 public Class<?> getDeclaringClass() {
227 return clazz;
228 }
229
230 /**
231 * Returns the name of the method represented by this {@code Method}
232 * object, as a {@code String}.
233 */
234 @Override
235 public String getName() {
236 return name;
237 }
238
239 /**
240 * {@inheritDoc}
241 * @jls 8.4.3 Method Modifiers
242 */
243 @Override
244 public int getModifiers() {
245 return modifiers;
246 }
247
248 /**
249 * {@inheritDoc}
250 * @throws GenericSignatureFormatError {@inheritDoc}
251 * @since 1.5
252 * @jls 8.4.4 Generic Methods
253 */
254 @Override
255 @SuppressWarnings({"rawtypes", "unchecked"})
256 public TypeVariable<Method>[] getTypeParameters() {
257 if (getGenericSignature() != null)
258 return (TypeVariable<Method>[])getGenericInfo().getTypeParameters();
259 else
260 return (TypeVariable<Method>[])GenericDeclRepository.EMPTY_TYPE_VARS;
261 }
262
263 /**
264 * Returns a {@code Class} object that represents the formal return type
265 * of the method represented by this {@code Method} object.
266 *
267 * @return the return type for the method this object represents
268 */
269 public Class<?> getReturnType() {
270 return returnType;
271 }
272
273 /**
274 * Returns a {@code Type} object that represents the formal return
275 * type of the method represented by this {@code Method} object.
276 *
277 * <p>If the return type is a parameterized type,
278 * the {@code Type} object returned must accurately reflect
279 * the actual type arguments used in the source code.
280 *
281 * <p>If the return type is a type variable or a parameterized type, it
282 * is created. Otherwise, it is resolved.
283 *
284 * @return a {@code Type} object that represents the formal return
285 * type of the underlying method
286 * @throws GenericSignatureFormatError
287 * if the generic method signature does not conform to the format
288 * specified in
289 * <cite>The Java Virtual Machine Specification</cite>
290 * @throws TypeNotPresentException if the underlying method's
291 * return type refers to a non-existent class or interface declaration
292 * @throws MalformedParameterizedTypeException if the
293 * underlying method's return type refers to a parameterized
294 * type that cannot be instantiated for any reason
295 * @since 1.5
296 */
297 public Type getGenericReturnType() {
298 if (getGenericSignature() != null) {
299 return getGenericInfo().getReturnType();
300 } else { return getReturnType();}
301 }
302
303 @Override
304 Class<?>[] getSharedParameterTypes() {
305 return parameterTypes;
306 }
307
308 @Override
309 Class<?>[] getSharedExceptionTypes() {
310 return exceptionTypes;
311 }
312
313 /**
314 * {@inheritDoc}
315 */
316 @Override
317 public Class<?>[] getParameterTypes() {
318 return parameterTypes.clone();
319 }
320
321 /**
322 * {@inheritDoc}
323 * @since 1.8
324 */
325 public int getParameterCount() { return parameterTypes.length; }
326
327
328 /**
329 * {@inheritDoc}
330 * @throws GenericSignatureFormatError {@inheritDoc}
331 * @throws TypeNotPresentException {@inheritDoc}
332 * @throws MalformedParameterizedTypeException {@inheritDoc}
333 * @since 1.5
334 */
335 @Override
336 public Type[] getGenericParameterTypes() {
337 return super.getGenericParameterTypes();
338 }
339
340 /**
341 * {@inheritDoc}
342 */
343 @Override
344 public Class<?>[] getExceptionTypes() {
345 return exceptionTypes.clone();
346 }
347
348 /**
349 * {@inheritDoc}
350 * @throws GenericSignatureFormatError {@inheritDoc}
351 * @throws TypeNotPresentException {@inheritDoc}
352 * @throws MalformedParameterizedTypeException {@inheritDoc}
353 * @since 1.5
354 */
355 @Override
356 public Type[] getGenericExceptionTypes() {
357 return super.getGenericExceptionTypes();
358 }
359
360 /**
361 * Compares this {@code Method} against the specified object. Returns
362 * true if the objects are the same. Two {@code Methods} are the same if
363 * they were declared by the same class and have the same name
364 * and formal parameter types and return type.
365 */
366 public boolean equals(Object obj) {
367 if (obj instanceof Method other) {
368 if ((getDeclaringClass() == other.getDeclaringClass())
369 && (getName() == other.getName())) {
370 if (!returnType.equals(other.getReturnType()))
371 return false;
372 return equalParamTypes(parameterTypes, other.parameterTypes);
373 }
374 }
375 return false;
376 }
377
378 /**
379 * Returns a hashcode for this {@code Method}. The hashcode is computed
380 * as the exclusive-or of the hashcodes for the underlying
381 * method's declaring class name and the method's name.
382 */
383 public int hashCode() {
384 return getDeclaringClass().getName().hashCode() ^ getName().hashCode();
385 }
386
387 /**
388 * Returns a string describing this {@code Method}. The string is
389 * formatted as the method access modifiers, if any, followed by
390 * the method return type, followed by a space, followed by the
391 * class declaring the method, followed by a period, followed by
392 * the method name, followed by a parenthesized, comma-separated
393 * list of the method's formal parameter types. If the method
394 * throws checked exceptions, the parameter list is followed by a
395 * space, followed by the word "{@code throws}" followed by a
396 * comma-separated list of the thrown exception types.
397 * For example:
398 * <pre>
399 * public boolean java.lang.Object.equals(java.lang.Object)
400 * </pre>
401 *
402 * <p>The access modifiers are placed in canonical order as
403 * specified by "The Java Language Specification". This is
404 * {@code public}, {@code protected} or {@code private} first,
405 * and then other modifiers in the following order:
406 * {@code abstract}, {@code default}, {@code static}, {@code final},
407 * {@code synchronized}, {@code native}, {@code strictfp}.
408 *
409 * @return a string describing this {@code Method}
410 *
411 * @jls 8.4.3 Method Modifiers
412 * @jls 9.4 Method Declarations
413 * @jls 9.6.1 Annotation Interface Elements
414 */
415 public String toString() {
416 return sharedToString(Modifier.methodModifiers(),
417 isDefault(),
418 parameterTypes,
419 exceptionTypes);
420 }
421
422 @Override
423 void specificToStringHeader(StringBuilder sb) {
424 sb.append(getReturnType().getTypeName()).append(' ');
425 sb.append(getDeclaringClassTypeName()).append('.');
426 sb.append(getName());
427 }
428
429 @Override
430 String toShortString() {
431 return "method " + getDeclaringClassTypeName() +
432 '.' + toShortSignature();
433 }
434
435 String toShortSignature() {
436 StringJoiner sj = new StringJoiner(",", getName() + "(", ")");
437 for (Class<?> parameterType : getSharedParameterTypes()) {
438 sj.add(parameterType.getTypeName());
439 }
440 return sj.toString();
441 }
442
443 /**
444 * Returns a string describing this {@code Method}, including type
445 * parameters. The string is formatted as the method access
446 * modifiers, if any, followed by an angle-bracketed
447 * comma-separated list of the method's type parameters, if any,
448 * including informative bounds of the type parameters, if any,
449 * followed by the method's generic return type, followed by a
450 * space, followed by the class declaring the method, followed by
451 * a period, followed by the method name, followed by a
452 * parenthesized, comma-separated list of the method's generic
453 * formal parameter types.
454 *
455 * If this method was declared to take a variable number of
456 * arguments, instead of denoting the last parameter as
457 * "<code><i>Type</i>[]</code>", it is denoted as
458 * "<code><i>Type</i>...</code>".
459 *
460 * A space is used to separate access modifiers from one another
461 * and from the type parameters or return type. If there are no
462 * type parameters, the type parameter list is elided; if the type
463 * parameter list is present, a space separates the list from the
464 * class name. If the method is declared to throw exceptions, the
465 * parameter list is followed by a space, followed by the word
466 * "{@code throws}" followed by a comma-separated list of the generic
467 * thrown exception types.
468 *
469 * <p>The access modifiers are placed in canonical order as
470 * specified by "The Java Language Specification". This is
471 * {@code public}, {@code protected} or {@code private} first,
472 * and then other modifiers in the following order:
473 * {@code abstract}, {@code default}, {@code static}, {@code final},
474 * {@code synchronized}, {@code native}, {@code strictfp}.
475 *
476 * @return a string describing this {@code Method},
477 * include type parameters
478 *
479 * @since 1.5
480 *
481 * @jls 8.4.3 Method Modifiers
482 * @jls 9.4 Method Declarations
483 * @jls 9.6.1 Annotation Interface Elements
484 */
485 @Override
486 public String toGenericString() {
487 return sharedToGenericString(Modifier.methodModifiers(), isDefault());
488 }
489
490 @Override
491 void specificToGenericStringHeader(StringBuilder sb) {
492 Type genRetType = getGenericReturnType();
493 sb.append(genRetType.getTypeName()).append(' ');
494 sb.append(getDeclaringClassTypeName()).append('.');
495 sb.append(getName());
496 }
497
498 /**
499 * Invokes the underlying method represented by this {@code Method}
500 * object, on the specified object with the specified parameters.
501 * Individual parameters are automatically unwrapped to match
502 * primitive formal parameters, and both primitive and reference
503 * parameters are subject to method invocation conversions as
504 * necessary.
505 *
506 * <p>If the underlying method is static, then the specified {@code obj}
507 * argument is ignored. It may be null.
508 *
509 * <p>If the number of formal parameters required by the underlying method is
510 * 0, the supplied {@code args} array may be of length 0 or null.
511 *
512 * <p>If the underlying method is an instance method, it is invoked
513 * using dynamic method lookup as documented in The Java Language
514 * Specification, section {@jls 15.12.4.4}; in particular,
515 * overriding based on the runtime type of the target object may occur.
516 *
517 * <p>If the underlying method is static, the class that declared
518 * the method is initialized if it has not already been initialized.
519 *
520 * <p>If the method completes normally, the value it returns is
521 * returned to the caller of invoke; if the value has a primitive
522 * type, it is first appropriately wrapped in an object. However,
523 * if the value has the type of an array of a primitive type, the
524 * elements of the array are <i>not</i> wrapped in objects; in
525 * other words, an array of primitive type is returned. If the
526 * underlying method return type is void, the invocation returns
527 * null.
528 *
529 * @param obj the object the underlying method is invoked from
530 * @param args the arguments used for the method call
531 * @return the result of dispatching the method represented by
532 * this object on {@code obj} with parameters
533 * {@code args}
534 *
535 * @throws IllegalAccessException if this {@code Method} object
536 * is enforcing Java language access control and the underlying
537 * method is inaccessible.
538 * @throws IllegalArgumentException if the method is an
539 * instance method and the specified object argument
540 * is not an instance of the class or interface
541 * declaring the underlying method (or of a subclass
542 * or implementor thereof); if the number of actual
543 * and formal parameters differ; if an unwrapping
544 * conversion for primitive arguments fails; or if,
545 * after possible unwrapping, a parameter value
546 * cannot be converted to the corresponding formal
547 * parameter type by a method invocation conversion.
548 * @throws InvocationTargetException if the underlying method
549 * throws an exception.
550 * @throws NullPointerException if the specified object is null
551 * and the method is an instance method.
552 * @throws ExceptionInInitializerError if the initialization
553 * provoked by this method fails.
554 */
555 @CallerSensitive
556 @ForceInline // to ensure Reflection.getCallerClass optimization
557 @IntrinsicCandidate
558 public Object invoke(Object obj, Object... args)
559 throws IllegalAccessException, InvocationTargetException
560 {
561 boolean callerSensitive = isCallerSensitive();
562 Class<?> caller = null;
563 if (!override || callerSensitive) {
564 caller = Reflection.getCallerClass();
565 }
566
567 // Reflection::getCallerClass filters all subclasses of
568 // jdk.internal.reflect.MethodAccessorImpl and Method::invoke(Object, Object[])
569 // Should not call Method::invoke(Object, Object[], Class) here
570 if (!override) {
571 checkAccess(caller, clazz,
572 Modifier.isStatic(modifiers) ? null : obj.getClass(),
573 modifiers);
574 }
575 MethodAccessor ma = methodAccessor; // read @Stable
576 if (ma == null) {
577 ma = acquireMethodAccessor();
578 }
579
580 return callerSensitive ? ma.invoke(obj, args, caller) : ma.invoke(obj, args);
581 }
582
583 /**
584 * This is to support MethodHandle calling caller-sensitive Method::invoke
585 * that may invoke a caller-sensitive method in order to get the original caller
586 * class (not the injected invoker).
587 *
588 * If this adapter is not presented, MethodHandle invoking Method::invoke
589 * will get an invoker class, a hidden nestmate of the original caller class,
590 * that becomes the caller class invoking Method::invoke.
591 */
592 @CallerSensitiveAdapter
593 private Object invoke(Object obj, Object[] args, Class<?> caller)
594 throws IllegalAccessException, InvocationTargetException
595 {
596 boolean callerSensitive = isCallerSensitive();
597 if (!override) {
598 checkAccess(caller, clazz,
599 Modifier.isStatic(modifiers) ? null : obj.getClass(),
600 modifiers);
601 }
602 MethodAccessor ma = methodAccessor; // read @Stable
603 if (ma == null) {
604 ma = acquireMethodAccessor();
605 }
606
607 return callerSensitive ? ma.invoke(obj, args, caller) : ma.invoke(obj, args);
608 }
609
610 @Stable private Boolean callerSensitive; // lazily initialize
611 private boolean isCallerSensitive() {
612 Boolean cs = callerSensitive;
613 if (cs == null) {
614 callerSensitive = cs = Reflection.isCallerSensitive(this);
615 }
616 return cs;
617 }
618
619 /**
620 * {@return {@code true} if this method is a bridge
621 * method; returns {@code false} otherwise}
622 *
623 * @apiNote
624 * A bridge method is a {@linkplain isSynthetic synthetic} method
625 * created by a Java compiler alongside a method originating from
626 * the source code. Bridge methods are used by Java compilers in
627 * various circumstances to span differences in Java programming
628 * language semantics and JVM semantics.
629 *
630 * <p>One example use of bridge methods is as a technique for a
631 * Java compiler to support <i>covariant overrides</i>, where a
632 * subclass overrides a method and gives the new method a more
633 * specific return type than the method in the superclass. While
634 * the Java language specification forbids a class declaring two
635 * methods with the same parameter types but a different return
636 * type, the virtual machine does not. A common case where
637 * covariant overrides are used is for a {@link
638 * java.lang.Cloneable Cloneable} class where the {@link
639 * Object#clone() clone} method inherited from {@code
640 * java.lang.Object} is overridden and declared to return the type
641 * of the class. For example, {@code Object} declares
642 * <pre>{@code protected Object clone() throws CloneNotSupportedException {...}}</pre>
643 * and {@code EnumSet<E>} declares its language-level {@linkplain
644 * java.util.EnumSet#clone() covariant override}
645 * <pre>{@code public EnumSet<E> clone() {...}}</pre>
646 * If this technique was being used, the resulting class file for
647 * {@code EnumSet} would have two {@code clone} methods, one
648 * returning {@code EnumSet<E>} and the second a bridge method
649 * returning {@code Object}. The bridge method is a JVM-level
650 * override of {@code Object.clone()}. The body of the {@code
651 * clone} bridge method calls its non-bridge counterpart and
652 * returns its result.
653 * @since 1.5
654 *
655 * @jls 8.4.8.3 Requirements in Overriding and Hiding
656 * @jls 15.12.4.5 Create Frame, Synchronize, Transfer Control
657 * @jvms 4.6 Methods
658 * @see <a
659 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
660 * programming language and JVM modeling in core reflection</a>
661 */
662 public boolean isBridge() {
663 return (getModifiers() & Modifier.BRIDGE) != 0;
664 }
665
666 /**
667 * {@inheritDoc}
668 * @since 1.5
669 * @jls 8.4.1 Formal Parameters
670 */
671 @Override
672 public boolean isVarArgs() {
673 return super.isVarArgs();
674 }
675
676 /**
677 * {@inheritDoc}
678 * @jls 13.1 The Form of a Binary
679 * @jvms 4.6 Methods
680 * @see <a
681 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
682 * programming language and JVM modeling in core reflection</a>
683 * @since 1.5
684 */
685 @Override
686 public boolean isSynthetic() {
687 return super.isSynthetic();
688 }
689
690 /**
691 * Returns {@code true} if this method is a default
692 * method; returns {@code false} otherwise.
693 *
694 * A default method is a public non-abstract instance method, that
695 * is, a non-static method with a body, declared in an interface.
696 *
697 * @return true if and only if this method is a default
698 * method as defined by the Java Language Specification.
699 * @since 1.8
700 * @jls 9.4 Method Declarations
701 */
702 public boolean isDefault() {
703 // Default methods are public non-abstract instance methods
704 // declared in an interface.
705 return ((getModifiers() & (Modifier.ABSTRACT | Modifier.PUBLIC | Modifier.STATIC)) ==
706 Modifier.PUBLIC) && getDeclaringClass().isInterface();
707 }
708
709 // NOTE that there is no synchronization used here. It is correct
710 // (though not efficient) to generate more than one MethodAccessor
711 // for a given Method. However, avoiding synchronization will
712 // probably make the implementation more scalable.
713 private MethodAccessor acquireMethodAccessor() {
714 // First check to see if one has been created yet, and take it
715 // if so
716 Method root = this.root;
717 MethodAccessor tmp = root == null ? null : root.getMethodAccessor();
718 if (tmp != null) {
719 methodAccessor = tmp;
720 } else {
721 // Otherwise fabricate one and propagate it up to the root
722 tmp = reflectionFactory.newMethodAccessor(this, isCallerSensitive());
723 // set the method accessor only if it's not using native implementation
724 if (VM.isJavaLangInvokeInited())
725 setMethodAccessor(tmp);
726 }
727
728 return tmp;
729 }
730
731 // Returns MethodAccessor for this Method object, not looking up
732 // the chain to the root
733 MethodAccessor getMethodAccessor() {
734 return methodAccessor;
735 }
736
737 // Sets the MethodAccessor for this Method object and
738 // (recursively) its root
739 void setMethodAccessor(MethodAccessor accessor) {
740 methodAccessor = accessor;
741 // Propagate up
742 Method root = this.root;
743 if (root != null) {
744 root.setMethodAccessor(accessor);
745 }
746 }
747
748 /**
749 * Returns the default value for the annotation member represented by
750 * this {@code Method} instance. If the member is of a primitive type,
751 * an instance of the corresponding wrapper type is returned. Returns
752 * null if no default is associated with the member, or if the method
753 * instance does not represent a declared member of an annotation type.
754 *
755 * @return the default value for the annotation member represented
756 * by this {@code Method} instance.
757 * @throws TypeNotPresentException if the annotation is of type
758 * {@link Class} and no definition can be found for the
759 * default class value.
760 * @since 1.5
761 * @jls 9.6.2 Defaults for Annotation Type Elements
762 */
763 public Object getDefaultValue() {
764 if (annotationDefault == null)
765 return null;
766 Class<?> memberType = AnnotationType.invocationHandlerReturnType(
767 getReturnType());
768 Object result = AnnotationParser.parseMemberValue(
769 memberType, ByteBuffer.wrap(annotationDefault),
770 SharedSecrets.getJavaLangAccess().
771 getConstantPool(getDeclaringClass()),
772 getDeclaringClass());
773 if (result instanceof ExceptionProxy) {
774 if (result instanceof TypeNotPresentExceptionProxy proxy) {
775 throw new TypeNotPresentException(proxy.typeName(), proxy.getCause());
776 }
777 throw new AnnotationFormatError("Invalid default: " + this);
778 }
779 return result;
780 }
781
782 /**
783 * {@inheritDoc}
784 * @throws NullPointerException {@inheritDoc}
785 * @since 1.5
786 */
787 @Override
788 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
789 return super.getAnnotation(annotationClass);
790 }
791
792 /**
793 * {@inheritDoc}
794 * @since 1.5
795 */
796 @Override
797 public Annotation[] getDeclaredAnnotations() {
798 return super.getDeclaredAnnotations();
799 }
800
801 /**
802 * {@inheritDoc}
803 * @since 1.5
804 */
805 @Override
806 public Annotation[][] getParameterAnnotations() {
807 return sharedGetParameterAnnotations(parameterTypes, parameterAnnotations);
808 }
809
810 /**
811 * {@inheritDoc}
812 * @since 1.8
813 */
814 @Override
815 public AnnotatedType getAnnotatedReturnType() {
816 return getAnnotatedReturnType0(getGenericReturnType());
817 }
818
819 @Override
820 boolean handleParameterNumberMismatch(int resultLength, Class<?>[] parameterTypes) {
821 throw new AnnotationFormatError("Parameter annotations don't match number of parameters");
822 }
823 }