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