1 /* 2 * Copyright (c) 1996, 2006, 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 sun.reflect.MethodAccessor; 29 import sun.reflect.Reflection; 30 import sun.reflect.generics.repository.MethodRepository; 31 import sun.reflect.generics.factory.CoreReflectionFactory; 32 import sun.reflect.generics.factory.GenericsFactory; 33 import sun.reflect.generics.scope.MethodScope; 34 import sun.reflect.annotation.AnnotationType; 35 import sun.reflect.annotation.AnnotationParser; 36 import java.lang.annotation.Annotation; 37 import java.lang.annotation.AnnotationFormatError; 38 import java.nio.ByteBuffer; 39 import java.util.Map; 40 41 /** 42 * A {@code Method} provides information about, and access to, a single method 43 * on a class or interface. The reflected method may be a class method 44 * or an instance method (including an abstract method). 45 * 46 * <p>A {@code Method} permits widening conversions to occur when matching the 47 * actual parameters to invoke with the underlying method's formal 48 * parameters, but it throws an {@code IllegalArgumentException} if a 49 * narrowing conversion would occur. 50 * 51 * @see Member 52 * @see java.lang.Class 53 * @see java.lang.Class#getMethods() 54 * @see java.lang.Class#getMethod(String, Class[]) 55 * @see java.lang.Class#getDeclaredMethods() 56 * @see java.lang.Class#getDeclaredMethod(String, Class[]) 57 * 58 * @author Kenneth Russell 59 * @author Nakul Saraiya 60 */ 61 public final 62 class Method extends AccessibleObject implements GenericDeclaration, 63 Member { 64 private Class<?> clazz; 65 private int slot; 66 // This is guaranteed to be interned by the VM in the 1.4 67 // reflection implementation 68 private String name; 69 private Class<?> returnType; 70 private Class<?>[] parameterTypes; 71 private Class<?>[] exceptionTypes; 72 private int modifiers; 73 // Generics and annotations support 74 private transient String signature; 75 // generic info repository; lazily initialized 76 private transient MethodRepository genericInfo; 77 private byte[] annotations; 78 private byte[] parameterAnnotations; 79 private byte[] annotationDefault; 80 private volatile MethodAccessor methodAccessor; 81 // For sharing of MethodAccessors. This branching structure is 82 // currently only two levels deep (i.e., one root Method and 83 // potentially many Method objects pointing to it.) 84 private Method root; 85 86 // Generics infrastructure 87 88 private String getGenericSignature() {return signature;} 89 90 // Accessor for factory 91 private GenericsFactory getFactory() { 92 // create scope and factory 93 return CoreReflectionFactory.make(this, MethodScope.make(this)); 94 } 95 96 // Accessor for generic info repository 97 private MethodRepository getGenericInfo() { 98 // lazily initialize repository if necessary 99 if (genericInfo == null) { 100 // create and cache generic info repository 101 genericInfo = MethodRepository.make(getGenericSignature(), 102 getFactory()); 103 } 104 return genericInfo; //return cached repository 105 } 106 107 /** 108 * Package-private constructor used by ReflectAccess to enable 109 * instantiation of these objects in Java code from the java.lang 110 * package via sun.reflect.LangReflectAccess. 111 */ 112 Method(Class<?> declaringClass, 113 String name, 114 Class<?>[] parameterTypes, 115 Class<?> returnType, 116 Class<?>[] checkedExceptions, 117 int modifiers, 118 int slot, 119 String signature, 120 byte[] annotations, 121 byte[] parameterAnnotations, 122 byte[] annotationDefault) 123 { 124 this.clazz = declaringClass; 125 this.name = name; 126 this.parameterTypes = parameterTypes; 127 this.returnType = returnType; 128 this.exceptionTypes = checkedExceptions; 129 this.modifiers = modifiers; 130 this.slot = slot; 131 this.signature = signature; 132 this.annotations = annotations; 133 this.parameterAnnotations = parameterAnnotations; 134 this.annotationDefault = annotationDefault; 135 } 136 137 /** 138 * Package-private routine (exposed to java.lang.Class via 139 * ReflectAccess) which returns a copy of this Method. The copy's 140 * "root" field points to this Method. 141 */ 142 Method copy() { 143 // This routine enables sharing of MethodAccessor objects 144 // among Method objects which refer to the same underlying 145 // method in the VM. (All of this contortion is only necessary 146 // because of the "accessibility" bit in AccessibleObject, 147 // which implicitly requires that new java.lang.reflect 148 // objects be fabricated for each reflective call on Class 149 // objects.) 150 Method res = new Method(clazz, name, parameterTypes, returnType, 151 exceptionTypes, modifiers, slot, signature, 152 annotations, parameterAnnotations, annotationDefault); 153 res.root = this; 154 // Might as well eagerly propagate this if already present 155 res.methodAccessor = methodAccessor; 156 return res; 157 } 158 159 /** 160 * Returns the {@code Class} object representing the class or interface 161 * that declares the method represented by this {@code Method} object. 162 */ 163 public Class<?> getDeclaringClass() { 164 return clazz; 165 } 166 167 /** 168 * Returns the name of the method represented by this {@code Method} 169 * object, as a {@code String}. 170 */ 171 public String getName() { 172 return name; 173 } 174 175 /** 176 * Returns the Java language modifiers for the method represented 177 * by this {@code Method} object, as an integer. The {@code Modifier} class should 178 * be used to decode the modifiers. 179 * 180 * @see Modifier 181 */ 182 public int getModifiers() { 183 return modifiers; 184 } 185 186 /** 187 * Returns an array of {@code TypeVariable} objects that represent the 188 * type variables declared by the generic declaration represented by this 189 * {@code GenericDeclaration} object, in declaration order. Returns an 190 * array of length 0 if the underlying generic declaration declares no type 191 * variables. 192 * 193 * @return an array of {@code TypeVariable} objects that represent 194 * the type variables declared by this generic declaration 195 * @throws GenericSignatureFormatError if the generic 196 * signature of this generic declaration does not conform to 197 * the format specified in 198 * <cite>The Java™ Virtual Machine Specification</cite> 199 * @since 1.5 200 */ 201 public TypeVariable<Method>[] getTypeParameters() { 202 if (getGenericSignature() != null) 203 return (TypeVariable<Method>[])getGenericInfo().getTypeParameters(); 204 else 205 return (TypeVariable<Method>[])new TypeVariable[0]; 206 } 207 208 /** 209 * Returns a {@code Class} object that represents the formal return type 210 * of the method represented by this {@code Method} object. 211 * 212 * @return the return type for the method this object represents 213 */ 214 public Class<?> getReturnType() { 215 return returnType; 216 } 217 218 /** 219 * Returns a {@code Type} object that represents the formal return 220 * type of the method represented by this {@code Method} object. 228 * 229 * @return a {@code Type} object that represents the formal return 230 * type of the underlying method 231 * @throws GenericSignatureFormatError 232 * if the generic method signature does not conform to the format 233 * specified in 234 * <cite>The Java™ Virtual Machine Specification</cite> 235 * @throws TypeNotPresentException if the underlying method's 236 * return type refers to a non-existent type declaration 237 * @throws MalformedParameterizedTypeException if the 238 * underlying method's return typed refers to a parameterized 239 * type that cannot be instantiated for any reason 240 * @since 1.5 241 */ 242 public Type getGenericReturnType() { 243 if (getGenericSignature() != null) { 244 return getGenericInfo().getReturnType(); 245 } else { return getReturnType();} 246 } 247 248 249 /** 250 * Returns an array of {@code Class} objects that represent the formal 251 * parameter types, in declaration order, of the method 252 * represented by this {@code Method} object. Returns an array of length 253 * 0 if the underlying method takes no parameters. 254 * 255 * @return the parameter types for the method this object 256 * represents 257 */ 258 public Class<?>[] getParameterTypes() { 259 return (Class<?>[]) parameterTypes.clone(); 260 } 261 262 /** 263 * Returns an array of {@code Type} objects that represent the formal 264 * parameter types, in declaration order, of the method represented by 265 * this {@code Method} object. Returns an array of length 0 if the 266 * underlying method takes no parameters. 267 * 268 * <p>If a formal parameter type is a parameterized type, 269 * the {@code Type} object returned for it must accurately reflect 270 * the actual type parameters used in the source code. 271 * 272 * <p>If a formal parameter type is a type variable or a parameterized 273 * type, it is created. Otherwise, it is resolved. 274 * 275 * @return an array of Types that represent the formal 276 * parameter types of the underlying method, in declaration order 277 * @throws GenericSignatureFormatError 278 * if the generic method signature does not conform to the format 279 * specified in 280 * <cite>The Java™ Virtual Machine Specification</cite> 281 * @throws TypeNotPresentException if any of the parameter 282 * types of the underlying method refers to a non-existent type 283 * declaration 284 * @throws MalformedParameterizedTypeException if any of 285 * the underlying method's parameter types refer to a parameterized 286 * type that cannot be instantiated for any reason 287 * @since 1.5 288 */ 289 public Type[] getGenericParameterTypes() { 290 if (getGenericSignature() != null) 291 return getGenericInfo().getParameterTypes(); 292 else 293 return getParameterTypes(); 294 } 295 296 297 /** 298 * Returns an array of {@code Class} objects that represent 299 * the types of the exceptions declared to be thrown 300 * by the underlying method 301 * represented by this {@code Method} object. Returns an array of length 302 * 0 if the method declares no exceptions in its {@code throws} clause. 303 * 304 * @return the exception types declared as being thrown by the 305 * method this object represents 306 */ 307 public Class<?>[] getExceptionTypes() { 308 return (Class<?>[]) exceptionTypes.clone(); 309 } 310 311 /** 312 * Returns an array of {@code Type} objects that represent the 313 * exceptions declared to be thrown by this {@code Method} object. 314 * Returns an array of length 0 if the underlying method declares 315 * no exceptions in its {@code throws} clause. 316 * 317 * <p>If an exception type is a type variable or a parameterized 318 * type, it is created. Otherwise, it is resolved. 319 * 320 * @return an array of Types that represent the exception types 321 * thrown by the underlying method 322 * @throws GenericSignatureFormatError 323 * if the generic method signature does not conform to the format 324 * specified in 325 * <cite>The Java™ Virtual Machine Specification</cite> 326 * @throws TypeNotPresentException if the underlying method's 327 * {@code throws} clause refers to a non-existent type declaration 328 * @throws MalformedParameterizedTypeException if 329 * the underlying method's {@code throws} clause refers to a 330 * parameterized type that cannot be instantiated for any reason 331 * @since 1.5 332 */ 333 public Type[] getGenericExceptionTypes() { 334 Type[] result; 335 if (getGenericSignature() != null && 336 ((result = getGenericInfo().getExceptionTypes()).length > 0)) 337 return result; 338 else 339 return getExceptionTypes(); 340 } 341 342 /** 343 * Compares this {@code Method} against the specified object. Returns 344 * true if the objects are the same. Two {@code Methods} are the same if 345 * they were declared by the same class and have the same name 346 * and formal parameter types and return type. 347 */ 348 public boolean equals(Object obj) { 349 if (obj != null && obj instanceof Method) { 350 Method other = (Method)obj; 351 if ((getDeclaringClass() == other.getDeclaringClass()) 352 && (getName() == other.getName())) { 353 if (!returnType.equals(other.getReturnType())) 354 return false; 355 /* Avoid unnecessary cloning */ 356 Class<?>[] params1 = parameterTypes; 357 Class<?>[] params2 = other.parameterTypes; 358 if (params1.length == params2.length) { 359 for (int i = 0; i < params1.length; i++) { 360 if (params1[i] != params2[i]) 361 return false; 362 } 363 return true; 364 } 365 } 366 } 367 return false; 368 } 369 370 /** 371 * Returns a hashcode for this {@code Method}. The hashcode is computed 372 * as the exclusive-or of the hashcodes for the underlying 373 * method's declaring class name and the method's name. 374 */ 375 public int hashCode() { 376 return getDeclaringClass().getName().hashCode() ^ getName().hashCode(); 377 } 378 379 /** 380 * Returns a string describing this {@code Method}. The string is 381 * formatted as the method access modifiers, if any, followed by 382 * the method return type, followed by a space, followed by the 383 * class declaring the method, followed by a period, followed by 384 * the method name, followed by a parenthesized, comma-separated 385 * list of the method's formal parameter types. If the method 386 * throws checked exceptions, the parameter list is followed by a 387 * space, followed by the word throws followed by a 388 * comma-separated list of the thrown exception types. 389 * For example: 390 * <pre> 391 * public boolean java.lang.Object.equals(java.lang.Object) 392 * </pre> 393 * 394 * <p>The access modifiers are placed in canonical order as 395 * specified by "The Java Language Specification". This is 396 * {@code public}, {@code protected} or {@code private} first, 397 * and then other modifiers in the following order: 398 * {@code abstract}, {@code static}, {@code final}, 399 * {@code synchronized}, {@code native}, {@code strictfp}. 400 */ 401 public String toString() { 402 try { 403 StringBuilder sb = new StringBuilder(); 404 int mod = getModifiers() & Modifier.methodModifiers(); 405 if (mod != 0) { 406 sb.append(Modifier.toString(mod)).append(' '); 407 } 408 sb.append(Field.getTypeName(getReturnType())).append(' '); 409 sb.append(Field.getTypeName(getDeclaringClass())).append('.'); 410 sb.append(getName()).append('('); 411 Class<?>[] params = parameterTypes; // avoid clone 412 for (int j = 0; j < params.length; j++) { 413 sb.append(Field.getTypeName(params[j])); 414 if (j < (params.length - 1)) 415 sb.append(','); 416 } 417 sb.append(')'); 418 Class<?>[] exceptions = exceptionTypes; // avoid clone 419 if (exceptions.length > 0) { 420 sb.append(" throws "); 421 for (int k = 0; k < exceptions.length; k++) { 422 sb.append(exceptions[k].getName()); 423 if (k < (exceptions.length - 1)) 424 sb.append(','); 425 } 426 } 427 return sb.toString(); 428 } catch (Exception e) { 429 return "<" + e + ">"; 430 } 431 } 432 433 /** 434 * Returns a string describing this {@code Method}, including 435 * type parameters. The string is formatted as the method access 436 * modifiers, if any, followed by an angle-bracketed 437 * comma-separated list of the method's type parameters, if any, 438 * followed by the method's generic return type, followed by a 439 * space, followed by the class declaring the method, followed by 440 * a period, followed by the method name, followed by a 441 * parenthesized, comma-separated list of the method's generic 442 * formal parameter types. 443 * 444 * If this method was declared to take a variable number of 445 * arguments, instead of denoting the last parameter as 446 * "<tt><i>Type</i>[]</tt>", it is denoted as 447 * "<tt><i>Type</i>...</tt>". 448 * 449 * A space is used to separate access modifiers from one another 450 * and from the type parameters or return type. If there are no 451 * type parameters, the type parameter list is elided; if the type 452 * parameter list is present, a space separates the list from the 453 * class name. If the method is declared to throw exceptions, the 454 * parameter list is followed by a space, followed by the word 455 * throws followed by a comma-separated list of the generic thrown 456 * exception types. If there are no type parameters, the type 457 * parameter list is elided. 458 * 459 * <p>The access modifiers are placed in canonical order as 460 * specified by "The Java Language Specification". This is 461 * {@code public}, {@code protected} or {@code private} first, 462 * and then other modifiers in the following order: 463 * {@code abstract}, {@code static}, {@code final}, 464 * {@code synchronized}, {@code native}, {@code strictfp}. 465 * 466 * @return a string describing this {@code Method}, 467 * include type parameters 468 * 469 * @since 1.5 470 */ 471 public String toGenericString() { 472 try { 473 StringBuilder sb = new StringBuilder(); 474 int mod = getModifiers() & Modifier.methodModifiers(); 475 if (mod != 0) { 476 sb.append(Modifier.toString(mod)).append(' '); 477 } 478 TypeVariable<?>[] typeparms = getTypeParameters(); 479 if (typeparms.length > 0) { 480 boolean first = true; 481 sb.append('<'); 482 for(TypeVariable<?> typeparm: typeparms) { 483 if (!first) 484 sb.append(','); 485 // Class objects can't occur here; no need to test 486 // and call Class.getName(). 487 sb.append(typeparm.toString()); 488 first = false; 489 } 490 sb.append("> "); 491 } 492 493 Type genRetType = getGenericReturnType(); 494 sb.append( ((genRetType instanceof Class<?>)? 495 Field.getTypeName((Class<?>)genRetType):genRetType.toString())) 496 .append(' '); 497 498 sb.append(Field.getTypeName(getDeclaringClass())).append('.'); 499 sb.append(getName()).append('('); 500 Type[] params = getGenericParameterTypes(); 501 for (int j = 0; j < params.length; j++) { 502 String param = (params[j] instanceof Class)? 503 Field.getTypeName((Class)params[j]): 504 (params[j].toString()); 505 if (isVarArgs() && (j == params.length - 1)) // replace T[] with T... 506 param = param.replaceFirst("\\[\\]$", "..."); 507 sb.append(param); 508 if (j < (params.length - 1)) 509 sb.append(','); 510 } 511 sb.append(')'); 512 Type[] exceptions = getGenericExceptionTypes(); 513 if (exceptions.length > 0) { 514 sb.append(" throws "); 515 for (int k = 0; k < exceptions.length; k++) { 516 sb.append((exceptions[k] instanceof Class)? 517 ((Class)exceptions[k]).getName(): 518 exceptions[k].toString()); 519 if (k < (exceptions.length - 1)) 520 sb.append(','); 521 } 522 } 523 return sb.toString(); 524 } catch (Exception e) { 525 return "<" + e + ">"; 526 } 527 } 528 529 /** 530 * Invokes the underlying method represented by this {@code Method} 531 * object, on the specified object with the specified parameters. 532 * Individual parameters are automatically unwrapped to match 533 * primitive formal parameters, and both primitive and reference 534 * parameters are subject to method invocation conversions as 535 * necessary. 536 * 537 * <p>If the underlying method is static, then the specified {@code obj} 538 * argument is ignored. It may be null. 539 * 540 * <p>If the number of formal parameters required by the underlying method is 541 * 0, the supplied {@code args} array may be of length 0 or null. 542 * 543 * <p>If the underlying method is an instance method, it is invoked 544 * using dynamic method lookup as documented in The Java Language 545 * Specification, Second Edition, section 15.12.4.4; in particular, 546 * overriding based on the runtime type of the target object will occur. 597 MethodAccessor ma = methodAccessor; // read volatile 598 if (ma == null) { 599 ma = acquireMethodAccessor(); 600 } 601 return ma.invoke(obj, args); 602 } 603 604 /** 605 * Returns {@code true} if this method is a bridge 606 * method; returns {@code false} otherwise. 607 * 608 * @return true if and only if this method is a bridge 609 * method as defined by the Java Language Specification. 610 * @since 1.5 611 */ 612 public boolean isBridge() { 613 return (getModifiers() & Modifier.BRIDGE) != 0; 614 } 615 616 /** 617 * Returns {@code true} if this method was declared to take 618 * a variable number of arguments; returns {@code false} 619 * otherwise. 620 * 621 * @return {@code true} if an only if this method was declared to 622 * take a variable number of arguments. 623 * @since 1.5 624 */ 625 public boolean isVarArgs() { 626 return (getModifiers() & Modifier.VARARGS) != 0; 627 } 628 629 /** 630 * Returns {@code true} if this method is a synthetic 631 * method; returns {@code false} otherwise. 632 * 633 * @return true if and only if this method is a synthetic 634 * method as defined by the Java Language Specification. 635 * @since 1.5 636 */ 637 public boolean isSynthetic() { 638 return Modifier.isSynthetic(getModifiers()); 639 } 640 641 // NOTE that there is no synchronization used here. It is correct 642 // (though not efficient) to generate more than one MethodAccessor 643 // for a given Method. However, avoiding synchronization will 644 // probably make the implementation more scalable. 645 private MethodAccessor acquireMethodAccessor() { 646 // First check to see if one has been created yet, and take it 647 // if so 648 MethodAccessor tmp = null; 649 if (root != null) tmp = root.getMethodAccessor(); 650 if (tmp != null) { 651 methodAccessor = tmp; 652 } else { 653 // Otherwise fabricate one and propagate it up to the root 654 tmp = reflectionFactory.newMethodAccessor(this); 655 setMethodAccessor(tmp); 656 } 657 658 return tmp; 659 } 660 661 // Returns MethodAccessor for this Method object, not looking up 662 // the chain to the root 663 MethodAccessor getMethodAccessor() { 664 return methodAccessor; 665 } 666 667 // Sets the MethodAccessor for this Method object and 668 // (recursively) its root 669 void setMethodAccessor(MethodAccessor accessor) { 670 methodAccessor = accessor; 671 // Propagate up 672 if (root != null) { 673 root.setMethodAccessor(accessor); 674 } 675 } 676 677 /** 678 * @throws NullPointerException {@inheritDoc} 679 * @since 1.5 680 */ 681 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) { 682 if (annotationClass == null) 683 throw new NullPointerException(); 684 685 return (T) declaredAnnotations().get(annotationClass); 686 } 687 688 /** 689 * @since 1.5 690 */ 691 public Annotation[] getDeclaredAnnotations() { 692 return AnnotationParser.toArray(declaredAnnotations()); 693 } 694 695 private transient Map<Class<? extends Annotation>, Annotation> declaredAnnotations; 696 697 private synchronized Map<Class<? extends Annotation>, Annotation> declaredAnnotations() { 698 if (declaredAnnotations == null) { 699 declaredAnnotations = AnnotationParser.parseAnnotations( 700 annotations, sun.misc.SharedSecrets.getJavaLangAccess(). 701 getConstantPool(getDeclaringClass()), 702 getDeclaringClass()); 703 } 704 return declaredAnnotations; 705 } 706 707 /** 708 * Returns the default value for the annotation member represented by 709 * this {@code Method} instance. If the member is of a primitive type, 710 * an instance of the corresponding wrapper type is returned. Returns 711 * null if no default is associated with the member, or if the method 712 * instance does not represent a declared member of an annotation type. 713 * 714 * @return the default value for the annotation member represented 715 * by this {@code Method} instance. 716 * @throws TypeNotPresentException if the annotation is of type 717 * {@link Class} and no definition can be found for the 718 * default class value. 719 * @since 1.5 720 */ 721 public Object getDefaultValue() { 722 if (annotationDefault == null) 723 return null; 724 Class<?> memberType = AnnotationType.invocationHandlerReturnType( 725 getReturnType()); 726 Object result = AnnotationParser.parseMemberValue( 727 memberType, ByteBuffer.wrap(annotationDefault), 728 sun.misc.SharedSecrets.getJavaLangAccess(). 729 getConstantPool(getDeclaringClass()), 730 getDeclaringClass()); 731 if (result instanceof sun.reflect.annotation.ExceptionProxy) 732 throw new AnnotationFormatError("Invalid default: " + this); 733 return result; 734 } 735 736 /** 737 * Returns an array of arrays that represent the annotations on the formal 738 * parameters, in declaration order, of the method represented by 739 * this {@code Method} object. (Returns an array of length zero if the 740 * underlying method is parameterless. If the method has one or more 741 * parameters, a nested array of length zero is returned for each parameter 742 * with no annotations.) The annotation objects contained in the returned 743 * arrays are serializable. The caller of this method is free to modify 744 * the returned arrays; it will have no effect on the arrays returned to 745 * other callers. 746 * 747 * @return an array of arrays that represent the annotations on the formal 748 * parameters, in declaration order, of the method represented by this 749 * Method object 750 * @since 1.5 751 */ 752 public Annotation[][] getParameterAnnotations() { 753 int numParameters = parameterTypes.length; 754 if (parameterAnnotations == null) 755 return new Annotation[numParameters][0]; 756 757 Annotation[][] result = AnnotationParser.parseParameterAnnotations( 758 parameterAnnotations, 759 sun.misc.SharedSecrets.getJavaLangAccess(). 760 getConstantPool(getDeclaringClass()), 761 getDeclaringClass()); 762 if (result.length != numParameters) 763 throw new java.lang.annotation.AnnotationFormatError( 764 "Parameter annotations don't match number of parameters"); 765 return result; 766 } 767 } | 1 /* 2 * Copyright (c) 1996, 2011, 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 sun.reflect.MethodAccessor; 29 import sun.reflect.Reflection; 30 import sun.reflect.generics.repository.MethodRepository; 31 import sun.reflect.generics.factory.CoreReflectionFactory; 32 import sun.reflect.generics.factory.GenericsFactory; 33 import sun.reflect.generics.scope.MethodScope; 34 import sun.reflect.annotation.AnnotationType; 35 import sun.reflect.annotation.AnnotationParser; 36 import java.lang.annotation.Annotation; 37 import java.lang.annotation.AnnotationFormatError; 38 import java.nio.ByteBuffer; 39 40 /** 41 * A {@code Method} provides information about, and access to, a single method 42 * on a class or interface. The reflected method may be a class method 43 * or an instance method (including an abstract method). 44 * 45 * <p>A {@code Method} permits widening conversions to occur when matching the 46 * actual parameters to invoke with the underlying method's formal 47 * parameters, but it throws an {@code IllegalArgumentException} if a 48 * narrowing conversion would occur. 49 * 50 * @see Member 51 * @see java.lang.Class 52 * @see java.lang.Class#getMethods() 53 * @see java.lang.Class#getMethod(String, Class[]) 54 * @see java.lang.Class#getDeclaredMethods() 55 * @see java.lang.Class#getDeclaredMethod(String, Class[]) 56 * 57 * @author Kenneth Russell 58 * @author Nakul Saraiya 59 */ 60 public final class Method extends Executable { 61 private Class<?> clazz; 62 private int slot; 63 // This is guaranteed to be interned by the VM in the 1.4 64 // reflection implementation 65 private String name; 66 private Class<?> returnType; 67 private Class<?>[] parameterTypes; 68 private Class<?>[] exceptionTypes; 69 private int modifiers; 70 // Generics and annotations support 71 private transient String signature; 72 // generic info repository; lazily initialized 73 private transient MethodRepository genericInfo; 74 private byte[] annotations; 75 private byte[] parameterAnnotations; 76 private byte[] annotationDefault; 77 private volatile MethodAccessor methodAccessor; 78 // For sharing of MethodAccessors. This branching structure is 79 // currently only two levels deep (i.e., one root Method and 80 // potentially many Method objects pointing to it.) 81 private Method root; 82 83 84 // Generics infrastructure 85 private String getGenericSignature() {return signature;} 86 87 // Accessor for factory 88 private GenericsFactory getFactory() { 89 // create scope and factory 90 return CoreReflectionFactory.make(this, MethodScope.make(this)); 91 } 92 93 // Accessor for generic info repository 94 @Override 95 MethodRepository getGenericInfo() { 96 // lazily initialize repository if necessary 97 if (genericInfo == null) { 98 // create and cache generic info repository 99 genericInfo = MethodRepository.make(getGenericSignature(), 100 getFactory()); 101 } 102 return genericInfo; //return cached repository 103 } 104 105 /** 106 * Package-private constructor used by ReflectAccess to enable 107 * instantiation of these objects in Java code from the java.lang 108 * package via sun.reflect.LangReflectAccess. 109 */ 110 Method(Class<?> declaringClass, 111 String name, 112 Class<?>[] parameterTypes, 113 Class<?> returnType, 114 Class<?>[] checkedExceptions, 115 int modifiers, 116 int slot, 117 String signature, 118 byte[] annotations, 119 byte[] parameterAnnotations, 120 byte[] annotationDefault) { 121 this.clazz = declaringClass; 122 this.name = name; 123 this.parameterTypes = parameterTypes; 124 this.returnType = returnType; 125 this.exceptionTypes = checkedExceptions; 126 this.modifiers = modifiers; 127 this.slot = slot; 128 this.signature = signature; 129 this.annotations = annotations; 130 this.parameterAnnotations = parameterAnnotations; 131 this.annotationDefault = annotationDefault; 132 } 133 134 /** 135 * Package-private routine (exposed to java.lang.Class via 136 * ReflectAccess) which returns a copy of this Method. The copy's 137 * "root" field points to this Method. 138 */ 139 Method copy() { 140 // This routine enables sharing of MethodAccessor objects 141 // among Method objects which refer to the same underlying 142 // method in the VM. (All of this contortion is only necessary 143 // because of the "accessibility" bit in AccessibleObject, 144 // which implicitly requires that new java.lang.reflect 145 // objects be fabricated for each reflective call on Class 146 // objects.) 147 Method res = new Method(clazz, name, parameterTypes, returnType, 148 exceptionTypes, modifiers, slot, signature, 149 annotations, parameterAnnotations, annotationDefault); 150 res.root = this; 151 // Might as well eagerly propagate this if already present 152 res.methodAccessor = methodAccessor; 153 return res; 154 } 155 156 @Override 157 boolean hasGenericInformation() { 158 return (getGenericSignature() != null); 159 } 160 161 @Override 162 byte[] getAnnotationBytes() { 163 return annotations; 164 } 165 166 /** 167 * {@inheritDoc} 168 */ 169 @Override 170 public Class<?> getDeclaringClass() { 171 return clazz; 172 } 173 174 /** 175 * Returns the name of the method represented by this {@code Method} 176 * object, as a {@code String}. 177 */ 178 @Override 179 public String getName() { 180 return name; 181 } 182 183 /** 184 * {@inheritDoc} 185 */ 186 @Override 187 public int getModifiers() { 188 return modifiers; 189 } 190 191 /** 192 * {@inheritDoc} 193 * @throws GenericSignatureFormatError {@inheritDoc} 194 * @since 1.5 195 */ 196 @Override 197 public TypeVariable<Method>[] getTypeParameters() { 198 if (getGenericSignature() != null) 199 return (TypeVariable<Method>[])getGenericInfo().getTypeParameters(); 200 else 201 return (TypeVariable<Method>[])new TypeVariable[0]; 202 } 203 204 /** 205 * Returns a {@code Class} object that represents the formal return type 206 * of the method represented by this {@code Method} object. 207 * 208 * @return the return type for the method this object represents 209 */ 210 public Class<?> getReturnType() { 211 return returnType; 212 } 213 214 /** 215 * Returns a {@code Type} object that represents the formal return 216 * type of the method represented by this {@code Method} object. 224 * 225 * @return a {@code Type} object that represents the formal return 226 * type of the underlying method 227 * @throws GenericSignatureFormatError 228 * if the generic method signature does not conform to the format 229 * specified in 230 * <cite>The Java™ Virtual Machine Specification</cite> 231 * @throws TypeNotPresentException if the underlying method's 232 * return type refers to a non-existent type declaration 233 * @throws MalformedParameterizedTypeException if the 234 * underlying method's return typed refers to a parameterized 235 * type that cannot be instantiated for any reason 236 * @since 1.5 237 */ 238 public Type getGenericReturnType() { 239 if (getGenericSignature() != null) { 240 return getGenericInfo().getReturnType(); 241 } else { return getReturnType();} 242 } 243 244 /** 245 * {@inheritDoc} 246 */ 247 @Override 248 public Class<?>[] getParameterTypes() { 249 return (Class<?>[]) parameterTypes.clone(); 250 } 251 252 /** 253 * {@inheritDoc} 254 * @throws GenericSignatureFormatError {@inheritDoc} 255 * @throws TypeNotPresentException {@inheritDoc} 256 * @throws MalformedParameterizedTypeException {@inheritDoc} 257 * @since 1.5 258 */ 259 @Override 260 public Type[] getGenericParameterTypes() { 261 return super.getGenericParameterTypes(); 262 } 263 264 /** 265 * {@inheritDoc} 266 */ 267 @Override 268 public Class<?>[] getExceptionTypes() { 269 return (Class<?>[]) exceptionTypes.clone(); 270 } 271 272 /** 273 * {@inheritDoc} 274 * @throws GenericSignatureFormatError {@inheritDoc} 275 * @throws TypeNotPresentException {@inheritDoc} 276 * @throws MalformedParameterizedTypeException {@inheritDoc} 277 * @since 1.5 278 */ 279 @Override 280 public Type[] getGenericExceptionTypes() { 281 return super.getGenericExceptionTypes(); 282 } 283 284 /** 285 * Compares this {@code Method} against the specified object. Returns 286 * true if the objects are the same. Two {@code Methods} are the same if 287 * they were declared by the same class and have the same name 288 * and formal parameter types and return type. 289 */ 290 public boolean equals(Object obj) { 291 if (obj != null && obj instanceof Method) { 292 Method other = (Method)obj; 293 if ((getDeclaringClass() == other.getDeclaringClass()) 294 && (getName() == other.getName())) { 295 if (!returnType.equals(other.getReturnType())) 296 return false; 297 return equalParamTypes(parameterTypes, other.parameterTypes); 298 } 299 } 300 return false; 301 } 302 303 /** 304 * Returns a hashcode for this {@code Method}. The hashcode is computed 305 * as the exclusive-or of the hashcodes for the underlying 306 * method's declaring class name and the method's name. 307 */ 308 public int hashCode() { 309 return getDeclaringClass().getName().hashCode() ^ getName().hashCode(); 310 } 311 312 /** 313 * Returns a string describing this {@code Method}. The string is 314 * formatted as the method access modifiers, if any, followed by 315 * the method return type, followed by a space, followed by the 316 * class declaring the method, followed by a period, followed by 317 * the method name, followed by a parenthesized, comma-separated 318 * list of the method's formal parameter types. If the method 319 * throws checked exceptions, the parameter list is followed by a 320 * space, followed by the word throws followed by a 321 * comma-separated list of the thrown exception types. 322 * For example: 323 * <pre> 324 * public boolean java.lang.Object.equals(java.lang.Object) 325 * </pre> 326 * 327 * <p>The access modifiers are placed in canonical order as 328 * specified by "The Java Language Specification". This is 329 * {@code public}, {@code protected} or {@code private} first, 330 * and then other modifiers in the following order: 331 * {@code abstract}, {@code static}, {@code final}, 332 * {@code synchronized}, {@code native}, {@code strictfp}. 333 */ 334 public String toString() { 335 return sharedToString(Modifier.methodModifiers(), 336 parameterTypes, 337 exceptionTypes); 338 } 339 340 @Override 341 void specificToStringHeader(StringBuilder sb) { 342 sb.append(Field.getTypeName(getReturnType())).append(' '); 343 sb.append(Field.getTypeName(getDeclaringClass())).append('.'); 344 sb.append(getName()); 345 } 346 347 /** 348 * Returns a string describing this {@code Method}, including 349 * type parameters. The string is formatted as the method access 350 * modifiers, if any, followed by an angle-bracketed 351 * comma-separated list of the method's type parameters, if any, 352 * followed by the method's generic return type, followed by a 353 * space, followed by the class declaring the method, followed by 354 * a period, followed by the method name, followed by a 355 * parenthesized, comma-separated list of the method's generic 356 * formal parameter types. 357 * 358 * If this method was declared to take a variable number of 359 * arguments, instead of denoting the last parameter as 360 * "<tt><i>Type</i>[]</tt>", it is denoted as 361 * "<tt><i>Type</i>...</tt>". 362 * 363 * A space is used to separate access modifiers from one another 364 * and from the type parameters or return type. If there are no 365 * type parameters, the type parameter list is elided; if the type 366 * parameter list is present, a space separates the list from the 367 * class name. If the method is declared to throw exceptions, the 368 * parameter list is followed by a space, followed by the word 369 * throws followed by a comma-separated list of the generic thrown 370 * exception types. If there are no type parameters, the type 371 * parameter list is elided. 372 * 373 * <p>The access modifiers are placed in canonical order as 374 * specified by "The Java Language Specification". This is 375 * {@code public}, {@code protected} or {@code private} first, 376 * and then other modifiers in the following order: 377 * {@code abstract}, {@code static}, {@code final}, 378 * {@code synchronized}, {@code native}, {@code strictfp}. 379 * 380 * @return a string describing this {@code Method}, 381 * include type parameters 382 * 383 * @since 1.5 384 */ 385 @Override 386 public String toGenericString() { 387 return sharedToGenericString(Modifier.methodModifiers()); 388 } 389 390 @Override 391 void specificToGenericStringHeader(StringBuilder sb) { 392 Type genRetType = getGenericReturnType(); 393 sb.append( ((genRetType instanceof Class<?>)? 394 Field.getTypeName((Class<?>)genRetType):genRetType.toString())) 395 .append(' '); 396 397 sb.append(Field.getTypeName(getDeclaringClass())).append('.'); 398 sb.append(getName()); 399 } 400 401 /** 402 * Invokes the underlying method represented by this {@code Method} 403 * object, on the specified object with the specified parameters. 404 * Individual parameters are automatically unwrapped to match 405 * primitive formal parameters, and both primitive and reference 406 * parameters are subject to method invocation conversions as 407 * necessary. 408 * 409 * <p>If the underlying method is static, then the specified {@code obj} 410 * argument is ignored. It may be null. 411 * 412 * <p>If the number of formal parameters required by the underlying method is 413 * 0, the supplied {@code args} array may be of length 0 or null. 414 * 415 * <p>If the underlying method is an instance method, it is invoked 416 * using dynamic method lookup as documented in The Java Language 417 * Specification, Second Edition, section 15.12.4.4; in particular, 418 * overriding based on the runtime type of the target object will occur. 469 MethodAccessor ma = methodAccessor; // read volatile 470 if (ma == null) { 471 ma = acquireMethodAccessor(); 472 } 473 return ma.invoke(obj, args); 474 } 475 476 /** 477 * Returns {@code true} if this method is a bridge 478 * method; returns {@code false} otherwise. 479 * 480 * @return true if and only if this method is a bridge 481 * method as defined by the Java Language Specification. 482 * @since 1.5 483 */ 484 public boolean isBridge() { 485 return (getModifiers() & Modifier.BRIDGE) != 0; 486 } 487 488 /** 489 * {@inheritDoc} 490 * @since 1.5 491 */ 492 @Override 493 public boolean isVarArgs() { 494 return super.isVarArgs(); 495 } 496 497 /** 498 * {@inheritDoc} 499 * @since 1.5 500 */ 501 @Override 502 public boolean isSynthetic() { 503 return super.isSynthetic(); 504 } 505 506 // NOTE that there is no synchronization used here. It is correct 507 // (though not efficient) to generate more than one MethodAccessor 508 // for a given Method. However, avoiding synchronization will 509 // probably make the implementation more scalable. 510 private MethodAccessor acquireMethodAccessor() { 511 // First check to see if one has been created yet, and take it 512 // if so 513 MethodAccessor tmp = null; 514 if (root != null) tmp = root.getMethodAccessor(); 515 if (tmp != null) { 516 methodAccessor = tmp; 517 } else { 518 // Otherwise fabricate one and propagate it up to the root 519 tmp = reflectionFactory.newMethodAccessor(this); 520 setMethodAccessor(tmp); 521 } 522 523 return tmp; 524 } 525 526 // Returns MethodAccessor for this Method object, not looking up 527 // the chain to the root 528 MethodAccessor getMethodAccessor() { 529 return methodAccessor; 530 } 531 532 // Sets the MethodAccessor for this Method object and 533 // (recursively) its root 534 void setMethodAccessor(MethodAccessor accessor) { 535 methodAccessor = accessor; 536 // Propagate up 537 if (root != null) { 538 root.setMethodAccessor(accessor); 539 } 540 } 541 542 /** 543 * Returns the default value for the annotation member represented by 544 * this {@code Method} instance. If the member is of a primitive type, 545 * an instance of the corresponding wrapper type is returned. Returns 546 * null if no default is associated with the member, or if the method 547 * instance does not represent a declared member of an annotation type. 548 * 549 * @return the default value for the annotation member represented 550 * by this {@code Method} instance. 551 * @throws TypeNotPresentException if the annotation is of type 552 * {@link Class} and no definition can be found for the 553 * default class value. 554 * @since 1.5 555 */ 556 public Object getDefaultValue() { 557 if (annotationDefault == null) 558 return null; 559 Class<?> memberType = AnnotationType.invocationHandlerReturnType( 560 getReturnType()); 561 Object result = AnnotationParser.parseMemberValue( 562 memberType, ByteBuffer.wrap(annotationDefault), 563 sun.misc.SharedSecrets.getJavaLangAccess(). 564 getConstantPool(getDeclaringClass()), 565 getDeclaringClass()); 566 if (result instanceof sun.reflect.annotation.ExceptionProxy) 567 throw new AnnotationFormatError("Invalid default: " + this); 568 return result; 569 } 570 571 /** 572 * {@inheritDoc} 573 * @throws NullPointerException {@inheritDoc} 574 * @since 1.5 575 */ 576 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) { 577 return super.getAnnotation(annotationClass); 578 } 579 580 /** 581 * {@inheritDoc} 582 * @since 1.5 583 */ 584 public Annotation[] getDeclaredAnnotations() { 585 return super.getDeclaredAnnotations(); 586 } 587 588 /** 589 * {@inheritDoc} 590 * @since 1.5 591 */ 592 @Override 593 public Annotation[][] getParameterAnnotations() { 594 return sharedGetParameterAnnotations(parameterTypes, parameterAnnotations); 595 } 596 597 @Override 598 void handleParameterNumberMismatch(int resultLength, int numParameters) { 599 throw new AnnotationFormatError("Parameter annotations don't match number of parameters"); 600 } 601 } |