1 /* 2 * Copyright (c) 1996, 2025, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.lang.reflect; 27 28 import jdk.internal.access.SharedSecrets; 29 import jdk.internal.misc.VM; 30 import jdk.internal.reflect.CallerSensitive; 31 import jdk.internal.reflect.CallerSensitiveAdapter; 32 import jdk.internal.reflect.MethodAccessor; 33 import jdk.internal.reflect.Reflection; 34 import jdk.internal.vm.annotation.ForceInline; 35 import jdk.internal.vm.annotation.IntrinsicCandidate; 36 import jdk.internal.vm.annotation.Stable; 37 import sun.reflect.annotation.ExceptionProxy; 38 import sun.reflect.annotation.TypeNotPresentExceptionProxy; 39 import sun.reflect.generics.repository.GenericDeclRepository; 40 import sun.reflect.generics.repository.MethodRepository; 41 import sun.reflect.generics.factory.CoreReflectionFactory; 42 import sun.reflect.generics.factory.GenericsFactory; 43 import sun.reflect.generics.scope.MethodScope; 44 import sun.reflect.annotation.AnnotationType; 45 import sun.reflect.annotation.AnnotationParser; 46 import java.lang.annotation.Annotation; 47 import java.lang.annotation.AnnotationFormatError; 48 import java.nio.ByteBuffer; 49 import java.util.Optional; 50 import java.util.StringJoiner; 51 import java.util.function.Function; 52 53 /** 54 * A {@code Method} provides information about, and access to, a single method 55 * on a class or interface. The reflected method may be a class method 56 * or an instance method (including an abstract method). 57 * 58 * <p>A {@code Method} permits widening conversions to occur when matching the 59 * actual parameters to invoke with the underlying method's formal 60 * parameters, but it throws an {@code IllegalArgumentException} if a 61 * narrowing conversion would occur. 62 * 63 * @see Member 64 * @see java.lang.Class 65 * @see java.lang.Class#getMethods() 66 * @see java.lang.Class#getMethod(String, Class[]) 67 * @see java.lang.Class#getDeclaredMethods() 68 * @see java.lang.Class#getDeclaredMethod(String, Class[]) 69 * 70 * @author Kenneth Russell 71 * @author Nakul Saraiya 72 * @since 1.1 73 */ 74 public final class Method extends Executable { 75 private final Class<?> clazz; 76 private final int slot; 77 // This is guaranteed to be interned by the VM in the 1.4 78 // reflection implementation 79 private final String name; 80 private final Class<?> returnType; 81 private final Class<?>[] parameterTypes; 82 private final Class<?>[] exceptionTypes; 83 private final int modifiers; 84 // Generics and annotations support 85 private final transient String signature; 86 private final byte[] annotations; 87 private final byte[] parameterAnnotations; 88 private final byte[] annotationDefault; 89 90 /** 91 * Methods are mutable due to {@link AccessibleObject#setAccessible(boolean)}. 92 * Thus, we return a new copy of a root each time a method is returned. 93 * Some lazily initialized immutable states can be stored on root and shared to the copies. 94 */ 95 private Method root; 96 private transient volatile MethodRepository genericInfo; 97 private @Stable MethodAccessor methodAccessor; 98 // End shared states 99 private int hash; // not shared right now, eligible if expensive 100 101 private volatile Optional<?> codeModel; 102 103 // Generics infrastructure 104 private String getGenericSignature() {return signature;} 105 106 // Accessor for factory 107 private GenericsFactory getFactory() { 108 // create scope and factory 109 return CoreReflectionFactory.make(this, MethodScope.make(this)); 110 } 111 112 // Accessor for generic info repository 113 @Override 114 MethodRepository getGenericInfo() { 115 var genericInfo = this.genericInfo; 116 if (genericInfo == null) { 117 var root = this.root; 118 if (root != null) { 119 genericInfo = root.getGenericInfo(); 120 } else { 121 genericInfo = MethodRepository.make(getGenericSignature(), getFactory()); 122 } 123 this.genericInfo = genericInfo; 124 } 125 return genericInfo; 126 } 127 128 /** 129 * Package-private constructor 130 */ 131 Method(Class<?> declaringClass, 132 String name, 133 Class<?>[] parameterTypes, 134 Class<?> returnType, 135 Class<?>[] checkedExceptions, 136 int modifiers, 137 int slot, 138 String signature, 139 byte[] annotations, 140 byte[] parameterAnnotations, 141 byte[] annotationDefault) { 142 this.clazz = declaringClass; 143 this.name = name; 144 this.parameterTypes = parameterTypes; 145 this.returnType = returnType; 146 this.exceptionTypes = checkedExceptions; 147 this.modifiers = modifiers; 148 this.slot = slot; 149 this.signature = signature; 150 this.annotations = annotations; 151 this.parameterAnnotations = parameterAnnotations; 152 this.annotationDefault = annotationDefault; 153 } 154 155 /** 156 * Package-private routine (exposed to java.lang.Class via 157 * ReflectAccess) which returns a copy of this Method. The copy's 158 * "root" field points to this Method. 159 */ 160 Method copy() { 161 if (this.root != null) 162 throw new IllegalArgumentException("Can not copy a non-root Method"); 163 164 Method res = new Method(clazz, name, parameterTypes, returnType, 165 exceptionTypes, modifiers, slot, signature, 166 annotations, parameterAnnotations, annotationDefault); 167 res.root = this; 168 // Propagate shared states 169 res.methodAccessor = methodAccessor; 170 res.genericInfo = genericInfo; 171 return res; 172 } 173 174 /** 175 * @throws InaccessibleObjectException {@inheritDoc} 176 */ 177 @Override 178 @CallerSensitive 179 public void setAccessible(boolean flag) { 180 if (flag) checkCanSetAccessible(Reflection.getCallerClass()); 181 setAccessible0(flag); 182 } 183 184 @Override 185 void checkCanSetAccessible(Class<?> caller) { 186 checkCanSetAccessible(caller, clazz); 187 } 188 189 @Override 190 Method getRoot() { 191 return root; 192 } 193 194 @Override 195 boolean hasGenericInformation() { 196 return (getGenericSignature() != null); 197 } 198 199 @Override 200 byte[] getAnnotationBytes() { 201 return annotations; 202 } 203 204 /** 205 * Returns the {@code Class} object representing the class or interface 206 * that declares the method represented by this object. 207 */ 208 @Override 209 public Class<?> getDeclaringClass() { 210 return clazz; 211 } 212 213 /** 214 * Returns the name of the method represented by this {@code Method} 215 * object, as a {@code String}. 216 */ 217 @Override 218 public String getName() { 219 return name; 220 } 221 222 /** 223 * {@inheritDoc} 224 * @jls 8.4.3 Method Modifiers 225 */ 226 @Override 227 public int getModifiers() { 228 return modifiers; 229 } 230 231 /* package */ 232 Optional<?> setCodeModelIfNeeded(Function<Method, Optional<?>> modelFactory) { 233 if (root != null) { 234 return root.setCodeModelIfNeeded(modelFactory); 235 } 236 Optional<?> localRef = codeModel; 237 if (localRef == null) { 238 synchronized (this) { 239 localRef = codeModel; 240 if (localRef == null) { 241 localRef = modelFactory.apply(this); 242 codeModel = localRef; 243 } 244 } 245 } 246 return localRef; 247 } 248 249 /** 250 * {@inheritDoc} 251 * @throws GenericSignatureFormatError {@inheritDoc} 252 * @since 1.5 253 * @jls 8.4.4 Generic Methods 254 */ 255 @Override 256 @SuppressWarnings("unchecked") 257 public TypeVariable<Method>[] getTypeParameters() { 258 if (getGenericSignature() != null) 259 return (TypeVariable<Method>[])getGenericInfo().getTypeParameters(); 260 else 261 return (TypeVariable<Method>[])GenericDeclRepository.EMPTY_TYPE_VARS; 262 } 263 264 /** 265 * Returns a {@code Class} object that represents the formal return type 266 * of the method represented by this {@code Method} object. 267 * 268 * @return the return type for the method this object represents 269 */ 270 public Class<?> getReturnType() { 271 return returnType; 272 } 273 274 /** 275 * Returns a {@code Type} object that represents the formal return 276 * type of the method represented by this {@code Method} object. 277 * 278 * <p>If the return type is a parameterized type, 279 * the {@code Type} object returned must accurately reflect 280 * the actual type arguments used in the source code. 281 * 282 * <p>If the return type is a type variable or a parameterized type, it 283 * is created. Otherwise, it is resolved. 284 * 285 * @return a {@code Type} object that represents the formal return 286 * type of the underlying method 287 * @throws GenericSignatureFormatError 288 * if the generic method signature does not conform to the format 289 * specified in 290 * <cite>The Java Virtual Machine Specification</cite> 291 * @throws TypeNotPresentException if the underlying method's 292 * return type refers to a non-existent class or interface declaration 293 * @throws MalformedParameterizedTypeException if the 294 * underlying method's return type refers to a parameterized 295 * type that cannot be instantiated for any reason 296 * @since 1.5 297 */ 298 public Type getGenericReturnType() { 299 if (getGenericSignature() != null) { 300 return getGenericInfo().getReturnType(); 301 } else { return getReturnType();} 302 } 303 304 @Override 305 Class<?>[] getSharedParameterTypes() { 306 return parameterTypes; 307 } 308 309 @Override 310 Class<?>[] getSharedExceptionTypes() { 311 return exceptionTypes; 312 } 313 314 /** 315 * {@inheritDoc} 316 */ 317 @Override 318 public Class<?>[] getParameterTypes() { 319 return parameterTypes.length == 0 ? parameterTypes: parameterTypes.clone(); 320 } 321 322 /** 323 * {@inheritDoc} 324 * @since 1.8 325 */ 326 public int getParameterCount() { return parameterTypes.length; } 327 328 329 /** 330 * {@inheritDoc} 331 * @throws GenericSignatureFormatError {@inheritDoc} 332 * @throws TypeNotPresentException {@inheritDoc} 333 * @throws MalformedParameterizedTypeException {@inheritDoc} 334 * @since 1.5 335 */ 336 @Override 337 public Type[] getGenericParameterTypes() { 338 return super.getGenericParameterTypes(); 339 } 340 341 /** 342 * {@inheritDoc} 343 */ 344 @Override 345 public Class<?>[] getExceptionTypes() { 346 return exceptionTypes.length == 0 ? exceptionTypes : exceptionTypes.clone(); 347 } 348 349 /** 350 * {@inheritDoc} 351 * @throws GenericSignatureFormatError {@inheritDoc} 352 * @throws TypeNotPresentException {@inheritDoc} 353 * @throws MalformedParameterizedTypeException {@inheritDoc} 354 * @since 1.5 355 */ 356 @Override 357 public Type[] getGenericExceptionTypes() { 358 return super.getGenericExceptionTypes(); 359 } 360 361 /** 362 * Compares this {@code Method} against the specified object. Returns 363 * true if the objects are the same. Two {@code Methods} are the same if 364 * they were declared by the same class and have the same name 365 * and formal parameter types and return type. 366 */ 367 public boolean equals(Object obj) { 368 if (obj instanceof Method other) { 369 if ((getDeclaringClass() == other.getDeclaringClass()) 370 && (getName() == other.getName())) { 371 if (!returnType.equals(other.getReturnType())) 372 return false; 373 return equalParamTypes(parameterTypes, other.parameterTypes); 374 } 375 } 376 return false; 377 } 378 379 /** 380 * Returns a hashcode for this {@code Method}. The hashcode is computed 381 * as the exclusive-or of the hashcodes for the underlying 382 * method's declaring class name and the method's name. 383 */ 384 public int hashCode() { 385 int hc = hash; 386 387 if (hc == 0) { 388 hc = hash = getDeclaringClass().getName().hashCode() ^ getName() 389 .hashCode(); 390 } 391 return hc; 392 } 393 394 /** 395 * Returns a string describing this {@code Method}. The string is 396 * formatted as the method access modifiers, if any, followed by 397 * the method return type, followed by a space, followed by the 398 * class declaring the method, followed by a period, followed by 399 * the method name, followed by a parenthesized, comma-separated 400 * list of the method's formal parameter types. If the method 401 * throws checked exceptions, the parameter list is followed by a 402 * space, followed by the word "{@code throws}" followed by a 403 * comma-separated list of the thrown exception types. 404 * For example: 405 * <pre> 406 * public boolean java.lang.Object.equals(java.lang.Object) 407 * </pre> 408 * 409 * <p>The access modifiers are placed in canonical order as 410 * specified by "The Java Language Specification". This is 411 * {@code public}, {@code protected} or {@code private} first, 412 * and then other modifiers in the following order: 413 * {@code abstract}, {@code default}, {@code static}, {@code final}, 414 * {@code synchronized}, {@code native}, {@code strictfp}. 415 * 416 * @return a string describing this {@code Method} 417 * 418 * @jls 8.4.3 Method Modifiers 419 * @jls 9.4 Method Declarations 420 * @jls 9.6.1 Annotation Interface Elements 421 */ 422 public String toString() { 423 return sharedToString(Modifier.methodModifiers(), 424 isDefault(), 425 parameterTypes, 426 exceptionTypes); 427 } 428 429 @Override 430 void specificToStringHeader(StringBuilder sb) { 431 sb.append(getReturnType().getTypeName()).append(' '); 432 sb.append(getDeclaringClass().getTypeName()).append('.'); 433 sb.append(getName()); 434 } 435 436 @Override 437 String toShortString() { 438 return "method " + getDeclaringClass().getTypeName() + 439 '.' + toShortSignature(); 440 } 441 442 String toShortSignature() { 443 StringJoiner sj = new StringJoiner(",", getName() + "(", ")"); 444 for (Class<?> parameterType : getSharedParameterTypes()) { 445 sj.add(parameterType.getTypeName()); 446 } 447 return sj.toString(); 448 } 449 450 /** 451 * Returns a string describing this {@code Method}, including type 452 * parameters. The string is formatted as the method access 453 * modifiers, if any, followed by an angle-bracketed 454 * comma-separated list of the method's type parameters, if any, 455 * including informative bounds of the type parameters, if any, 456 * followed by the method's generic return type, followed by a 457 * space, followed by the class declaring the method, followed by 458 * a period, followed by the method name, followed by a 459 * parenthesized, comma-separated list of the method's generic 460 * formal parameter types. 461 * 462 * If this method was declared to take a variable number of 463 * arguments, instead of denoting the last parameter as 464 * "<code><i>Type</i>[]</code>", it is denoted as 465 * "<code><i>Type</i>...</code>". 466 * 467 * A space is used to separate access modifiers from one another 468 * and from the type parameters or return type. If there are no 469 * type parameters, the type parameter list is elided; if the type 470 * parameter list is present, a space separates the list from the 471 * class name. If the method is declared to throw exceptions, the 472 * parameter list is followed by a space, followed by the word 473 * "{@code throws}" followed by a comma-separated list of the generic 474 * thrown exception types. 475 * 476 * <p>The access modifiers are placed in canonical order as 477 * specified by "The Java Language Specification". This is 478 * {@code public}, {@code protected} or {@code private} first, 479 * and then other modifiers in the following order: 480 * {@code abstract}, {@code default}, {@code static}, {@code final}, 481 * {@code synchronized}, {@code native}, {@code strictfp}. 482 * 483 * @return a string describing this {@code Method}, 484 * include type parameters 485 * 486 * @since 1.5 487 * 488 * @jls 8.4.3 Method Modifiers 489 * @jls 9.4 Method Declarations 490 * @jls 9.6.1 Annotation Interface Elements 491 */ 492 @Override 493 public String toGenericString() { 494 return sharedToGenericString(Modifier.methodModifiers(), isDefault()); 495 } 496 497 @Override 498 void specificToGenericStringHeader(StringBuilder sb) { 499 Type genRetType = getGenericReturnType(); 500 sb.append(genRetType.getTypeName()).append(' '); 501 sb.append(getDeclaringClass().getTypeName()).append('.'); 502 sb.append(getName()); 503 } 504 505 /** 506 * Invokes the underlying method represented by this {@code Method} 507 * object, on the specified object with the specified parameters. 508 * Individual parameters are automatically unwrapped to match 509 * primitive formal parameters, and both primitive and reference 510 * parameters are subject to method invocation conversions as 511 * necessary. 512 * 513 * <p>If the underlying method is static, then the specified {@code obj} 514 * argument is ignored. It may be null. 515 * 516 * <p>If the number of formal parameters required by the underlying method is 517 * 0, the supplied {@code args} array may be of length 0 or null. 518 * 519 * <p>If the underlying method is an instance method, it is invoked 520 * using dynamic method lookup as documented in The Java Language 521 * Specification, section {@jls 15.12.4.4}; in particular, 522 * overriding based on the runtime type of the target object may occur. 523 * 524 * <p>If the underlying method is static, the class that declared 525 * the method is initialized if it has not already been initialized. 526 * 527 * <p>If the method completes normally, the value it returns is 528 * returned to the caller of invoke; if the value has a primitive 529 * type, it is first appropriately wrapped in an object. However, 530 * if the value has the type of an array of a primitive type, the 531 * elements of the array are <i>not</i> wrapped in objects; in 532 * other words, an array of primitive type is returned. If the 533 * underlying method return type is void, the invocation returns 534 * null. 535 * 536 * @param obj the object the underlying method is invoked from 537 * @param args the arguments used for the method call 538 * @return the result of dispatching the method represented by 539 * this object on {@code obj} with parameters 540 * {@code args} 541 * 542 * @throws IllegalAccessException if this {@code Method} object 543 * is enforcing Java language access control and the underlying 544 * method is inaccessible. 545 * @throws IllegalArgumentException if the method is an 546 * instance method and the specified object argument 547 * is not an instance of the class or interface 548 * declaring the underlying method (or of a subclass 549 * or implementor thereof); if the number of actual 550 * and formal parameters differ; if an unwrapping 551 * conversion for primitive arguments fails; or if, 552 * after possible unwrapping, a parameter value 553 * cannot be converted to the corresponding formal 554 * parameter type by a method invocation conversion. 555 * @throws InvocationTargetException if the underlying method 556 * throws an exception. 557 * @throws NullPointerException if the specified object is null 558 * and the method is an instance method. 559 * @throws ExceptionInInitializerError if the initialization 560 * provoked by this method fails. 561 */ 562 @CallerSensitive 563 @ForceInline // to ensure Reflection.getCallerClass optimization 564 @IntrinsicCandidate 565 public Object invoke(Object obj, Object... args) 566 throws IllegalAccessException, InvocationTargetException 567 { 568 boolean callerSensitive = isCallerSensitive(); 569 Class<?> caller = null; 570 if (!override || callerSensitive) { 571 caller = Reflection.getCallerClass(); 572 } 573 574 // Reflection::getCallerClass filters all subclasses of 575 // jdk.internal.reflect.MethodAccessorImpl and Method::invoke(Object, Object[]) 576 // Should not call Method::invoke(Object, Object[], Class) here 577 if (!override) { 578 checkAccess(caller, clazz, 579 Modifier.isStatic(modifiers) ? null : obj.getClass(), 580 modifiers); 581 } 582 MethodAccessor ma = methodAccessor; // read @Stable 583 if (ma == null) { 584 ma = acquireMethodAccessor(); 585 } 586 587 return callerSensitive ? ma.invoke(obj, args, caller) : ma.invoke(obj, args); 588 } 589 590 /** 591 * This is to support MethodHandle calling caller-sensitive Method::invoke 592 * that may invoke a caller-sensitive method in order to get the original caller 593 * class (not the injected invoker). 594 * 595 * If this adapter is not presented, MethodHandle invoking Method::invoke 596 * will get an invoker class, a hidden nestmate of the original caller class, 597 * that becomes the caller class invoking Method::invoke. 598 */ 599 @CallerSensitiveAdapter 600 private Object invoke(Object obj, Object[] args, Class<?> caller) 601 throws IllegalAccessException, InvocationTargetException 602 { 603 boolean callerSensitive = isCallerSensitive(); 604 if (!override) { 605 checkAccess(caller, clazz, 606 Modifier.isStatic(modifiers) ? null : obj.getClass(), 607 modifiers); 608 } 609 MethodAccessor ma = methodAccessor; // read @Stable 610 if (ma == null) { 611 ma = acquireMethodAccessor(); 612 } 613 614 return callerSensitive ? ma.invoke(obj, args, caller) : ma.invoke(obj, args); 615 } 616 617 // 0 = not initialized (@Stable contract) 618 // 1 = initialized, CS 619 // -1 = initialized, not CS 620 @Stable private byte callerSensitive; 621 622 private boolean isCallerSensitive() { 623 byte cs = callerSensitive; 624 if (cs == 0) { 625 callerSensitive = cs = (byte)(Reflection.isCallerSensitive(this) ? 1 : -1); 626 } 627 return (cs > 0); 628 } 629 630 /** 631 * {@return {@code true} if this method is a bridge 632 * method; returns {@code false} otherwise} 633 * 634 * @apiNote 635 * A bridge method is a {@linkplain isSynthetic synthetic} method 636 * created by a Java compiler alongside a method originating from 637 * the source code. Bridge methods are used by Java compilers in 638 * various circumstances to span differences in Java programming 639 * language semantics and JVM semantics. 640 * 641 * <p>One example use of bridge methods is as a technique for a 642 * Java compiler to support <i>covariant overrides</i>, where a 643 * subclass overrides a method and gives the new method a more 644 * specific return type than the method in the superclass. While 645 * the Java language specification forbids a class declaring two 646 * methods with the same parameter types but a different return 647 * type, the virtual machine does not. A common case where 648 * covariant overrides are used is for a {@link 649 * java.lang.Cloneable Cloneable} class where the {@link 650 * Object#clone() clone} method inherited from {@code 651 * java.lang.Object} is overridden and declared to return the type 652 * of the class. For example, {@code Object} declares 653 * <pre>{@code protected Object clone() throws CloneNotSupportedException {...}}</pre> 654 * and {@code EnumSet<E>} declares its language-level {@linkplain 655 * java.util.EnumSet#clone() covariant override} 656 * <pre>{@code public EnumSet<E> clone() {...}}</pre> 657 * If this technique was being used, the resulting class file for 658 * {@code EnumSet} would have two {@code clone} methods, one 659 * returning {@code EnumSet<E>} and the second a bridge method 660 * returning {@code Object}. The bridge method is a JVM-level 661 * override of {@code Object.clone()}. The body of the {@code 662 * clone} bridge method calls its non-bridge counterpart and 663 * returns its result. 664 * @since 1.5 665 * 666 * @jls 8.4.8.3 Requirements in Overriding and Hiding 667 * @jls 15.12.4.5 Create Frame, Synchronize, Transfer Control 668 * @jvms 4.6 Methods 669 * @see <a 670 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java 671 * programming language and JVM modeling in core reflection</a> 672 */ 673 public boolean isBridge() { 674 return (getModifiers() & Modifier.BRIDGE) != 0; 675 } 676 677 /** 678 * {@inheritDoc} 679 * @since 1.5 680 * @jls 8.4.1 Formal Parameters 681 */ 682 @Override 683 public boolean isVarArgs() { 684 return super.isVarArgs(); 685 } 686 687 /** 688 * {@inheritDoc} 689 * @jls 13.1 The Form of a Binary 690 * @jvms 4.6 Methods 691 * @see <a 692 * href="{@docRoot}/java.base/java/lang/reflect/package-summary.html#LanguageJvmModel">Java 693 * programming language and JVM modeling in core reflection</a> 694 * @since 1.5 695 */ 696 @Override 697 public boolean isSynthetic() { 698 return super.isSynthetic(); 699 } 700 701 /** 702 * Returns {@code true} if this method is a default 703 * method; returns {@code false} otherwise. 704 * 705 * A default method is a public non-abstract instance method, that 706 * is, a non-static method with a body, declared in an interface. 707 * 708 * @return true if and only if this method is a default 709 * method as defined by the Java Language Specification. 710 * @since 1.8 711 * @jls 9.4 Method Declarations 712 */ 713 public boolean isDefault() { 714 // Default methods are public non-abstract instance methods 715 // declared in an interface. 716 return ((getModifiers() & (Modifier.ABSTRACT | Modifier.PUBLIC | Modifier.STATIC)) == 717 Modifier.PUBLIC) && getDeclaringClass().isInterface(); 718 } 719 720 // NOTE that there is no synchronization used here. It is correct 721 // (though not efficient) to generate more than one MethodAccessor 722 // for a given Method. However, avoiding synchronization will 723 // probably make the implementation more scalable. 724 private MethodAccessor acquireMethodAccessor() { 725 // First check to see if one has been created yet, and take it 726 // if so 727 Method root = this.root; 728 MethodAccessor tmp = root == null ? null : root.getMethodAccessor(); 729 if (tmp != null) { 730 methodAccessor = tmp; 731 } else { 732 // Otherwise fabricate one and propagate it up to the root 733 tmp = reflectionFactory.newMethodAccessor(this, isCallerSensitive()); 734 // set the method accessor only if it's not using native implementation 735 if (VM.isJavaLangInvokeInited()) 736 setMethodAccessor(tmp); 737 } 738 739 return tmp; 740 } 741 742 // Returns MethodAccessor for this Method object, not looking up 743 // the chain to the root 744 MethodAccessor getMethodAccessor() { 745 return methodAccessor; 746 } 747 748 // Sets the MethodAccessor for this Method object and 749 // (recursively) its root 750 void setMethodAccessor(MethodAccessor accessor) { 751 methodAccessor = accessor; 752 // Propagate up 753 Method root = this.root; 754 if (root != null) { 755 root.setMethodAccessor(accessor); 756 } 757 } 758 759 /** 760 * Returns the default value for the annotation member represented by 761 * this {@code Method} instance. If the member is of a primitive type, 762 * an instance of the corresponding wrapper type is returned. Returns 763 * null if no default is associated with the member, or if the method 764 * instance does not represent a declared member of an annotation type. 765 * 766 * @return the default value for the annotation member represented 767 * by this {@code Method} instance. 768 * @throws TypeNotPresentException if the annotation is of type 769 * {@link Class} and no definition can be found for the 770 * default class value. 771 * @since 1.5 772 * @jls 9.6.2 Defaults for Annotation Interface Elements 773 */ 774 public Object getDefaultValue() { 775 if (annotationDefault == null) 776 return null; 777 Class<?> memberType = AnnotationType.invocationHandlerReturnType( 778 getReturnType()); 779 Object result = AnnotationParser.parseMemberValue( 780 memberType, ByteBuffer.wrap(annotationDefault), 781 SharedSecrets.getJavaLangAccess(). 782 getConstantPool(getDeclaringClass()), 783 getDeclaringClass()); 784 if (result instanceof ExceptionProxy) { 785 if (result instanceof TypeNotPresentExceptionProxy proxy) { 786 throw new TypeNotPresentException(proxy.typeName(), proxy.getCause()); 787 } 788 throw new AnnotationFormatError("Invalid default: " + this); 789 } 790 return result; 791 } 792 793 /** 794 * {@inheritDoc} 795 * @throws NullPointerException {@inheritDoc} 796 * @since 1.5 797 */ 798 @Override 799 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) { 800 return super.getAnnotation(annotationClass); 801 } 802 803 /** 804 * {@inheritDoc} 805 * @since 1.5 806 */ 807 @Override 808 public Annotation[] getDeclaredAnnotations() { 809 return super.getDeclaredAnnotations(); 810 } 811 812 /** 813 * {@inheritDoc} 814 * @since 1.5 815 */ 816 @Override 817 public Annotation[][] getParameterAnnotations() { 818 return sharedGetParameterAnnotations(parameterTypes, parameterAnnotations); 819 } 820 821 /** 822 * {@inheritDoc} 823 * @since 1.8 824 */ 825 @Override 826 public AnnotatedType getAnnotatedReturnType() { 827 return getAnnotatedReturnType0(getGenericReturnType()); 828 } 829 830 @Override 831 boolean handleParameterNumberMismatch(int resultLength, Class<?>[] parameterTypes) { 832 throw new AnnotationFormatError("Parameter annotations don't match number of parameters"); 833 } 834 }