1 /*
  2  * Copyright (c) 1996, 2021, 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.MethodRepository;
 40 import sun.reflect.generics.factory.CoreReflectionFactory;
 41 import sun.reflect.generics.factory.GenericsFactory;
 42 import sun.reflect.generics.scope.MethodScope;
 43 import sun.reflect.annotation.AnnotationType;
 44 import sun.reflect.annotation.AnnotationParser;
 45 import java.lang.annotation.Annotation;
 46 import java.lang.annotation.AnnotationFormatError;
 47 import java.nio.ByteBuffer;
 48 import java.util.StringJoiner;
 49 
 50 /**
 51  * A {@code Method} provides information about, and access to, a single method
 52  * on a class or interface.  The reflected method may be a class method
 53  * or an instance method (including an abstract method).
 54  *
 55  * <p>A {@code Method} permits widening conversions to occur when matching the
 56  * actual parameters to invoke with the underlying method's formal
 57  * parameters, but it throws an {@code IllegalArgumentException} if a
 58  * narrowing conversion would occur.
 59  *
 60  * @see Member
 61  * @see java.lang.Class
 62  * @see java.lang.Class#getMethods()
 63  * @see java.lang.Class#getMethod(String, Class[])
 64  * @see java.lang.Class#getDeclaredMethods()
 65  * @see java.lang.Class#getDeclaredMethod(String, Class[])
 66  *
 67  * @author Kenneth Russell
 68  * @author Nakul Saraiya
 69  * @since 1.1
 70  */
 71 public final class Method extends Executable {
 72     private final Class<?>            clazz;
 73     private final int                 slot;

 74     // This is guaranteed to be interned by the VM in the 1.4
 75     // reflection implementation
 76     private final String              name;
 77     private final Class<?>            returnType;
 78     private final Class<?>[]          parameterTypes;
 79     private final Class<?>[]          exceptionTypes;
 80     private final int                 modifiers;

 81     // Generics and annotations support
 82     private final transient String    signature;
 83     // generic info repository; lazily initialized
 84     private transient MethodRepository genericInfo;
 85     private final byte[]              annotations;
 86     private final byte[]              parameterAnnotations;
 87     private final byte[]              annotationDefault;
 88     @Stable
 89     private MethodAccessor      methodAccessor;
 90     // For sharing of MethodAccessors. This branching structure is
 91     // currently only two levels deep (i.e., one root Method and
 92     // potentially many Method objects pointing to it.)
 93     //
 94     // If this branching structure would ever contain cycles, deadlocks can
 95     // occur in annotation code.
 96     private Method              root;
 97 
 98     // Generics infrastructure
 99     private String getGenericSignature() {return signature;}
100 
101     // Accessor for factory
102     private GenericsFactory getFactory() {
103         // create scope and factory
104         return CoreReflectionFactory.make(this, MethodScope.make(this));
105     }
106 
107     // Accessor for generic info repository
108     @Override
109     MethodRepository getGenericInfo() {
110         // lazily initialize repository if necessary
111         if (genericInfo == null) {
112             // create and cache generic info repository
113             genericInfo = MethodRepository.make(getGenericSignature(),
114                                                 getFactory());
115         }
116         return genericInfo; //return cached repository
117     }
118 
119     /**
120      * Package-private constructor
121      */
122     Method(Class<?> declaringClass,
123            String name,
124            Class<?>[] parameterTypes,
125            Class<?> returnType,
126            Class<?>[] checkedExceptions,
127            int modifiers,
128            int slot,
129            String signature,
130            byte[] annotations,
131            byte[] parameterAnnotations,
132            byte[] annotationDefault) {
133         assert declaringClass.isPrimaryType();
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>[])new TypeVariable[0];
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(getDeclaringClassTypeName()).append('.');
424         sb.append(getName());
425     }
426 
427     @Override
428     String toShortString() {
429         return "method " + getDeclaringClassTypeName() +
430                 '.' + toShortSignature();
431     }
432 
433     String toShortSignature() {
434         StringJoiner sj = new StringJoiner(",", getName() + "(", ")");
435         for (Class<?> parameterType : getParameterTypes()) {
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(getDeclaringClassTypeName()).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     @Stable private Boolean callerSensitive;       // lazily initialize
609     private boolean isCallerSensitive() {
610         Boolean cs = callerSensitive;
611         if (cs == null) {
612             callerSensitive = cs = Reflection.isCallerSensitive(this);
613         }
614         return cs;
615     }
616 
617     /**
618      * {@return {@code true} if this method is a bridge
619      * method; returns {@code false} otherwise}
620      *
621      * @apiNote
622      * A bridge method is a {@linkplain isSynthetic synthetic} method
623      * created by a Java compiler alongside a method originating from
624      * the source code. Bridge methods are used by Java compilers in
625      * various circumstances to span differences in Java programming
626      * language semantics and JVM semantics.
627      *
628      * <p>One example use of bridge methods is as a technique for a
629      * Java compiler to support <i>covariant overrides</i>, where a
630      * subclass overrides a method and gives the new method a more
631      * specific return type than the method in the superclass.  While
632      * the Java language specification forbids a class declaring two
633      * methods with the same parameter types but a different return
634      * type, the virtual machine does not. A common case where
635      * covariant overrides are used is for a {@link
636      * java.lang.Cloneable Cloneable} class where the {@link
637      * Object#clone() clone} method inherited from {@code
638      * java.lang.Object} is overridden and declared to return the type
639      * of the class. For example, {@code Object} declares
640      * <pre>{@code protected Object clone() throws CloneNotSupportedException {...}}</pre>
641      * and {@code EnumSet<E>} declares its language-level {@linkplain
642      * java.util.EnumSet#clone() covariant override}
643      * <pre>{@code public EnumSet<E> clone() {...}}</pre>
644      * If this technique was being used, the resulting class file for
645      * {@code EnumSet} would have two {@code clone} methods, one
646      * returning {@code EnumSet<E>} and the second a bridge method
647      * returning {@code Object}. The bridge method is a JVM-level
648      * override of {@code Object.clone()}.  The body of the {@code
649      * clone} bridge method calls its non-bridge counterpart and
650      * returns its result.
651      * @since 1.5
652      *
653      * @jls 8.4.8.3 Requirements in Overriding and Hiding
654      * @jls 15.12.4.5 Create Frame, Synchronize, Transfer Control
655      * @jvms 4.6 Methods
656      * @see <a
657      * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
658      * programming language and JVM modeling in core reflection</a>
659      */
660     public boolean isBridge() {
661         return (getModifiers() & Modifier.BRIDGE) != 0;
662     }
663 
664     /**
665      * {@inheritDoc}
666      * @since 1.5
667      * @jls 8.4.1 Formal Parameters
668      */
669     @Override
670     public boolean isVarArgs() {
671         return super.isVarArgs();
672     }
673 
674     /**
675      * {@inheritDoc}
676      * @jls 13.1 The Form of a Binary
677      * @jvms 4.6 Methods
678      * @see <a
679      * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java
680      * programming language and JVM modeling in core reflection</a>
681      * @since 1.5
682      */
683     @Override
684     public boolean isSynthetic() {
685         return super.isSynthetic();
686     }
687 
688     /**
689      * Returns {@code true} if this method is a default
690      * method; returns {@code false} otherwise.
691      *
692      * A default method is a public non-abstract instance method, that
693      * is, a non-static method with a body, declared in an interface.
694      *
695      * @return true if and only if this method is a default
696      * method as defined by the Java Language Specification.
697      * @since 1.8
698      * @jls 9.4 Method Declarations
699      */
700     public boolean isDefault() {
701         // Default methods are public non-abstract instance methods
702         // declared in an interface.
703         return ((getModifiers() & (Modifier.ABSTRACT | Modifier.PUBLIC | Modifier.STATIC)) ==
704                 Modifier.PUBLIC) && getDeclaringClass().isInterface();
705     }
706 
707     // NOTE that there is no synchronization used here. It is correct
708     // (though not efficient) to generate more than one MethodAccessor
709     // for a given Method. However, avoiding synchronization will
710     // probably make the implementation more scalable.
711     private MethodAccessor acquireMethodAccessor() {
712         // First check to see if one has been created yet, and take it
713         // if so
714         Method root = this.root;
715         MethodAccessor tmp = root == null ? null : root.getMethodAccessor();
716         if (tmp != null) {
717             methodAccessor = tmp;
718         } else {
719             // Otherwise fabricate one and propagate it up to the root
720             tmp = reflectionFactory.newMethodAccessor(this, isCallerSensitive());
721             // set the method accessor only if it's not using native implementation
722             if (VM.isJavaLangInvokeInited())
723                 setMethodAccessor(tmp);
724         }
725 
726         return tmp;
727     }
728 
729     // Returns MethodAccessor for this Method object, not looking up
730     // the chain to the root
731     MethodAccessor getMethodAccessor() {
732         return methodAccessor;
733     }
734 
735     // Sets the MethodAccessor for this Method object and
736     // (recursively) its root
737     void setMethodAccessor(MethodAccessor accessor) {
738         methodAccessor = accessor;
739         // Propagate up
740         Method root = this.root;
741         if (root != null) {
742             root.setMethodAccessor(accessor);
743         }
744     }
745 
746     /**
747      * Returns the default value for the annotation member represented by
748      * this {@code Method} instance.  If the member is of a primitive type,
749      * an instance of the corresponding wrapper type is returned. Returns
750      * null if no default is associated with the member, or if the method
751      * instance does not represent a declared member of an annotation type.
752      *
753      * @return the default value for the annotation member represented
754      *     by this {@code Method} instance.
755      * @throws TypeNotPresentException if the annotation is of type
756      *     {@link Class} and no definition can be found for the
757      *     default class value.
758      * @since  1.5
759      * @jls 9.6.2 Defaults for Annotation Type Elements
760      */
761     public Object getDefaultValue() {
762         if  (annotationDefault == null)
763             return null;
764         Class<?> memberType = AnnotationType.invocationHandlerReturnType(
765             getReturnType());
766         Object result = AnnotationParser.parseMemberValue(
767             memberType, ByteBuffer.wrap(annotationDefault),
768             SharedSecrets.getJavaLangAccess().
769                 getConstantPool(getDeclaringClass()),
770             getDeclaringClass());
771         if (result instanceof ExceptionProxy) {
772             if (result instanceof TypeNotPresentExceptionProxy proxy) {
773                 throw new TypeNotPresentException(proxy.typeName(), proxy.getCause());
774             }
775             throw new AnnotationFormatError("Invalid default: " + this);
776         }
777         return result;
778     }
779 
780     /**
781      * {@inheritDoc}
782      * @throws NullPointerException {@inheritDoc}
783      * @since 1.5
784      */
785     @Override
786     public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
787         return super.getAnnotation(annotationClass);
788     }
789 
790     /**
791      * {@inheritDoc}
792      * @since 1.5
793      */
794     @Override
795     public Annotation[] getDeclaredAnnotations()  {
796         return super.getDeclaredAnnotations();
797     }
798 
799     /**
800      * {@inheritDoc}
801      * @since 1.5
802      */
803     @Override
804     public Annotation[][] getParameterAnnotations() {
805         return sharedGetParameterAnnotations(parameterTypes, parameterAnnotations);
806     }
807 
808     /**
809      * {@inheritDoc}
810      * @since 1.8
811      */
812     @Override
813     public AnnotatedType getAnnotatedReturnType() {
814         return getAnnotatedReturnType0(getGenericReturnType());
815     }
816 
817     @Override
818     boolean handleParameterNumberMismatch(int resultLength, Class<?>[] parameterTypes) {
819         throw new AnnotationFormatError("Parameter annotations don't match number of parameters");
820     }
821 }
--- EOF ---