1 /* 2 * Copyright (c) 2012, 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 java.lang.annotation.*; 29 import java.util.Collections; 30 import java.util.Map; 31 import java.util.Objects; 32 import sun.reflect.annotation.AnnotationParser; 33 import sun.reflect.annotation.AnnotationSupport; 34 import sun.reflect.generics.repository.ConstructorRepository; 35 36 /** 37 * A shared superclass for the common functionality of {@link Method} 38 * and {@link Constructor}. 39 * 40 * @since 1.8 41 */ 42 public abstract class Executable extends AccessibleObject 43 implements Member, GenericDeclaration { 44 /* 45 * Only grant package-visibility to the constructor. 46 */ 47 Executable() {} 48 49 /** 50 * Accessor method to allow code sharing 51 */ 52 abstract byte[] getAnnotationBytes(); 53 54 /** 55 * Does the Executable have generic information. 56 */ 57 abstract boolean hasGenericInformation(); 58 59 abstract ConstructorRepository getGenericInfo(); 60 61 boolean equalParamTypes(Class<?>[] params1, Class<?>[] params2) { 62 /* Avoid unnecessary cloning */ 63 if (params1.length == params2.length) { 64 for (int i = 0; i < params1.length; i++) { 65 if (params1[i] != params2[i]) 66 return false; 67 } 68 return true; 69 } 70 return false; 71 } 72 73 Annotation[][] parseParameterAnnotations(byte[] parameterAnnotations) { 74 return AnnotationParser.parseParameterAnnotations( 75 parameterAnnotations, 76 sun.misc.SharedSecrets.getJavaLangAccess(). 77 getConstantPool(getDeclaringClass()), 78 getDeclaringClass()); 79 } 80 81 void separateWithCommas(Class<?>[] types, StringBuilder sb) { 82 for (int j = 0; j < types.length; j++) { 83 sb.append(Field.getTypeName(types[j])); 84 if (j < (types.length - 1)) 85 sb.append(","); 86 } 87 88 } 89 90 void printModifiersIfNonzero(StringBuilder sb, int mask) { 91 int mod = getModifiers() & mask; 92 if (mod != 0) { 93 sb.append(Modifier.toString(mod)).append(' '); 94 } 95 } 96 97 String sharedToString(int modifierMask, 98 Class<?>[] parameterTypes, 99 Class<?>[] exceptionTypes) { 100 try { 101 StringBuilder sb = new StringBuilder(); 102 103 printModifiersIfNonzero(sb, modifierMask); 104 specificToStringHeader(sb); 105 106 sb.append('('); 107 separateWithCommas(parameterTypes, sb); 108 sb.append(')'); 109 if (exceptionTypes.length > 0) { 110 sb.append(" throws "); 111 separateWithCommas(exceptionTypes, sb); 112 } 113 return sb.toString(); 114 } catch (Exception e) { 115 return "<" + e + ">"; 116 } 117 } 118 119 /** 120 * Generate toString header information specific to a method or 121 * constructor. 122 */ 123 abstract void specificToStringHeader(StringBuilder sb); 124 125 String sharedToGenericString(int modifierMask) { 126 try { 127 StringBuilder sb = new StringBuilder(); 128 129 printModifiersIfNonzero(sb, modifierMask); 130 131 TypeVariable<?>[] typeparms = getTypeParameters(); 132 if (typeparms.length > 0) { 133 boolean first = true; 134 sb.append('<'); 135 for(TypeVariable<?> typeparm: typeparms) { 136 if (!first) 137 sb.append(','); 138 // Class objects can't occur here; no need to test 139 // and call Class.getName(). 140 sb.append(typeparm.toString()); 141 first = false; 142 } 143 sb.append("> "); 144 } 145 146 specificToGenericStringHeader(sb); 147 148 sb.append('('); 149 Type[] params = getGenericParameterTypes(); 150 for (int j = 0; j < params.length; j++) { 151 String param = (params[j] instanceof Class)? 152 Field.getTypeName((Class)params[j]): 153 (params[j].toString()); 154 if (isVarArgs() && (j == params.length - 1)) // replace T[] with T... 155 param = param.replaceFirst("\\[\\]$", "..."); 156 sb.append(param); 157 if (j < (params.length - 1)) 158 sb.append(','); 159 } 160 sb.append(')'); 161 Type[] exceptions = getGenericExceptionTypes(); 162 if (exceptions.length > 0) { 163 sb.append(" throws "); 164 for (int k = 0; k < exceptions.length; k++) { 165 sb.append((exceptions[k] instanceof Class)? 166 ((Class)exceptions[k]).getName(): 167 exceptions[k].toString()); 168 if (k < (exceptions.length - 1)) 169 sb.append(','); 170 } 171 } 172 return sb.toString(); 173 } catch (Exception e) { 174 return "<" + e + ">"; 175 } 176 } 177 178 /** 179 * Generate toGenericString header information specific to a 180 * method or constructor. 181 */ 182 abstract void specificToGenericStringHeader(StringBuilder sb); 183 184 /** 185 * Returns the {@code Class} object representing the class or interface 186 * that declares the executable represented by this object. 187 */ 188 public abstract Class<?> getDeclaringClass(); 189 190 /** 191 * Returns the name of the executable represented by this object. 192 */ 193 public abstract String getName(); 194 195 /** 196 * Returns the Java language {@linkplain Modifier modifiers} for 197 * the executable represented by this object. 198 */ 199 public abstract int getModifiers(); 200 201 /** 202 * Returns an array of {@code TypeVariable} objects that represent the 203 * type variables declared by the generic declaration represented by this 204 * {@code GenericDeclaration} object, in declaration order. Returns an 205 * array of length 0 if the underlying generic declaration declares no type 206 * variables. 207 * 208 * @return an array of {@code TypeVariable} objects that represent 209 * the type variables declared by this generic declaration 210 * @throws GenericSignatureFormatError if the generic 211 * signature of this generic declaration does not conform to 212 * the format specified in 213 * <cite>The Java™ Virtual Machine Specification</cite> 214 */ 215 public abstract TypeVariable<?>[] getTypeParameters(); 216 217 /** 218 * Returns an array of {@code Class} objects that represent the formal 219 * parameter types, in declaration order, of the executable 220 * represented by this object. Returns an array of length 221 * 0 if the underlying executable takes no parameters. 222 * 223 * @return the parameter types for the executable this object 224 * represents 225 */ 226 public abstract Class<?>[] getParameterTypes(); 227 228 /** 229 * Returns the number of formal parameters (including any 230 * synthetic or synthesized parameters) for the executable 231 * represented by this object. 232 * 233 * @return The number of formal parameters for the executable this 234 * object represents 235 */ 236 public int getParameterCount() { 237 throw new AbstractMethodError(); 238 } 239 240 /** 241 * Returns an array of {@code Type} objects that represent the formal 242 * parameter types, in declaration order, of the executable represented by 243 * this object. Returns an array of length 0 if the 244 * underlying executable takes no parameters. 245 * 246 * <p>If a formal parameter type is a parameterized type, 247 * the {@code Type} object returned for it must accurately reflect 248 * the actual type parameters used in the source code. 249 * 250 * <p>If a formal parameter type is a type variable or a parameterized 251 * type, it is created. Otherwise, it is resolved. 252 * 253 * @return an array of {@code Type}s that represent the formal 254 * parameter types of the underlying executable, in declaration order 255 * @throws GenericSignatureFormatError 256 * if the generic method signature does not conform to the format 257 * specified in 258 * <cite>The Java™ Virtual Machine Specification</cite> 259 * @throws TypeNotPresentException if any of the parameter 260 * types of the underlying executable refers to a non-existent type 261 * declaration 262 * @throws MalformedParameterizedTypeException if any of 263 * the underlying executable's parameter types refer to a parameterized 264 * type that cannot be instantiated for any reason 265 */ 266 public Type[] getGenericParameterTypes() { 267 if (hasGenericInformation()) 268 return getGenericInfo().getParameterTypes(); 269 else 270 return getParameterTypes(); 271 } 272 273 /** 274 * Returns an array of {@code Parameter} objects that represent 275 * all the parameters to the underlying executable represented by 276 * this object. Returns an array of length 0 if the executable 277 * has no parameters. 278 * 279 * @return an array of {@code Parameter} objects representing all 280 * the parameters to the executable this object represents 281 */ 282 public Parameter[] getParameters() { 283 // TODO: This may eventually need to be guarded by security 284 // mechanisms similar to those in Field, Method, etc. 285 // 286 // Need to copy the cached array to prevent users from messing 287 // with it. Since parameters are immutable, we can 288 // shallow-copy. 289 return privateGetParameters().clone(); 290 } 291 292 private Parameter[] synthesizeAllParams() { 293 final int realparams = getParameterCount(); 294 final Parameter[] out = new Parameter[realparams]; 295 for (int i = 0; i < realparams; i++) 296 // TODO: is there a way to synthetically derive the 297 // modifiers? Probably not in the general case, since 298 // we'd have no way of knowing about them, but there 299 // may be specific cases. 300 out[i] = new Parameter("arg" + i, 0, this, i); 301 return out; 302 } 303 304 private Parameter[] privateGetParameters() { 305 // Use tmp to avoid multiple writes to a volatile. 306 Parameter[] tmp = parameters; 307 308 if (tmp == null) { 309 310 // Otherwise, go to the JVM to get them 311 tmp = getParameters0(); 312 313 // If we get back nothing, then synthesize parameters 314 if (tmp == null) 315 tmp = synthesizeAllParams(); 316 317 parameters = tmp; 318 319 } 320 321 return tmp; 322 } 323 324 private transient volatile Parameter[] parameters; 325 326 private native Parameter[] getParameters0(); 327 328 /** 329 * Returns an array of {@code Class} objects that represent the 330 * types of exceptions declared to be thrown by the underlying 331 * executable represented by this object. Returns an array of 332 * length 0 if the executable declares no exceptions in its {@code 333 * throws} clause. 334 * 335 * @return the exception types declared as being thrown by the 336 * executable this object represents 337 */ 338 public abstract Class<?>[] getExceptionTypes(); 339 340 /** 341 * Returns an array of {@code Type} objects that represent the 342 * exceptions declared to be thrown by this executable object. 343 * Returns an array of length 0 if the underlying executable declares 344 * no exceptions in its {@code throws} clause. 345 * 346 * <p>If an exception type is a type variable or a parameterized 347 * type, it is created. Otherwise, it is resolved. 348 * 349 * @return an array of Types that represent the exception types 350 * thrown by the underlying executable 351 * @throws GenericSignatureFormatError 352 * if the generic method signature does not conform to the format 353 * specified in 354 * <cite>The Java™ Virtual Machine Specification</cite> 355 * @throws TypeNotPresentException if the underlying executable's 356 * {@code throws} clause refers to a non-existent type declaration 357 * @throws MalformedParameterizedTypeException if 358 * the underlying executable's {@code throws} clause refers to a 359 * parameterized type that cannot be instantiated for any reason 360 */ 361 public Type[] getGenericExceptionTypes() { 362 Type[] result; 363 if (hasGenericInformation() && 364 ((result = getGenericInfo().getExceptionTypes()).length > 0)) 365 return result; 366 else 367 return getExceptionTypes(); 368 } 369 370 /** 371 * Returns a string describing this {@code Executable}, including 372 * any type parameters. 373 */ 374 public abstract String toGenericString(); 375 376 /** 377 * Returns {@code true} if this executable was declared to take a 378 * variable number of arguments; returns {@code false} otherwise. 379 * 380 * @return {@code true} if an only if this executable was declared 381 * to take a variable number of arguments. 382 */ 383 public boolean isVarArgs() { 384 return (getModifiers() & Modifier.VARARGS) != 0; 385 } 386 387 /** 388 * Returns {@code true} if this executable is a synthetic 389 * construct; returns {@code false} otherwise. 390 * 391 * @return true if and only if this executable is a synthetic 392 * construct as defined by 393 * <cite>The Java™ Language Specification</cite>. 394 * @jls 13.1 The Form of a Binary 395 */ 396 public boolean isSynthetic() { 397 return Modifier.isSynthetic(getModifiers()); 398 } 399 400 /** 401 * Returns an array of arrays that represent the annotations on 402 * the formal parameters, in declaration order, of the executable 403 * represented by this object. (Returns an array of length zero if 404 * the underlying executable is parameterless. If the executable has 405 * one or more parameters, a nested array of length zero is 406 * returned for each parameter with no annotations.) The 407 * annotation objects contained in the returned arrays are 408 * serializable. The caller of this method is free to modify the 409 * returned arrays; it will have no effect on the arrays returned 410 * to other callers. 411 * 412 * @return an array of arrays that represent the annotations on the formal 413 * parameters, in declaration order, of the executable represented by this 414 * object 415 */ 416 public abstract Annotation[][] getParameterAnnotations(); 417 418 Annotation[][] sharedGetParameterAnnotations(Class<?>[] parameterTypes, 419 byte[] parameterAnnotations) { 420 int numParameters = parameterTypes.length; 421 if (parameterAnnotations == null) 422 return new Annotation[numParameters][0]; 423 424 Annotation[][] result = parseParameterAnnotations(parameterAnnotations); 425 426 if (result.length != numParameters) 427 handleParameterNumberMismatch(result.length, numParameters); 428 return result; 429 } 430 431 abstract void handleParameterNumberMismatch(int resultLength, int numParameters); 432 433 /** 434 * {@inheritDoc} 435 * @throws NullPointerException {@inheritDoc} 436 */ 437 public <T extends Annotation> T getAnnotation(Class<T> annotationClass) { 438 Objects.requireNonNull(annotationClass); 439 440 return AnnotationSupport.getOneAnnotation(declaredAnnotations(), annotationClass); 441 } 442 443 /** 444 * {@inheritDoc} 445 * @throws NullPointerException {@inheritDoc} 446 * @since 1.8 447 */ 448 public <T extends Annotation> T[] getAnnotations(Class<T> annotationClass) { 449 Objects.requireNonNull(annotationClass); 450 451 return AnnotationSupport.getMultipleAnnotations(declaredAnnotations(), annotationClass); 452 } 453 454 /** 455 * {@inheritDoc} 456 */ 457 public Annotation[] getDeclaredAnnotations() { 458 return AnnotationSupport.unpackToArray(declaredAnnotations()); 459 } 460 461 private transient Map<Class<? extends Annotation>, Annotation> declaredAnnotations; 462 463 private synchronized Map<Class<? extends Annotation>, Annotation> declaredAnnotations() { 464 if (declaredAnnotations == null) { 465 declaredAnnotations = AnnotationParser.parseAnnotations( 466 getAnnotationBytes(), 467 sun.misc.SharedSecrets.getJavaLangAccess(). 468 getConstantPool(getDeclaringClass()), 469 getDeclaringClass()); 470 } 471 return declaredAnnotations; 472 } 473 474 }