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.Annotation; 29 import java.lang.annotation.AnnotationFormatError; 30 31 /** 32 * Represents an annotated element of the program currently running in this 33 * VM. This interface allows annotations to be read reflectively. All 34 * annotations returned by methods in this interface are immutable and 35 * serializable. The arrays returned by methods of this interface may be modified 36 * by callers without affecting the arrays returned to other callers. 37 * 38 * <p>The {@link #getAnnotationsByType(Class)} and {@link 39 * #getDeclaredAnnotationsByType(Class)} methods support multiple 40 * annotations of the same type on an element. If the argument to 41 * either method is a repeatable annotation type (JLS 9.6), then the 42 * method will "look through" a container annotation (JLS 9.7), if 43 * present, and return any annotations inside the container. Container 44 * annotations may be generated at compile-time to wrap multiple 45 * annotations of the argument type. 46 * 47 * <p>The terms <em>directly present</em>, <em>indirectly present</em>, 48 * <em>present</em>, and <em>associated</em> are used throughout this 49 * interface to describe precisely which annotations are returned by 205 * @return annotations present on this element 206 * @since 1.5 207 */ 208 Annotation[] getAnnotations(); 209 210 /** 211 * Returns annotations that are <em>associated</em> with this element. 212 * 213 * If there are no annotations <em>associated</em> with this element, the return 214 * value is an array of length 0. 215 * 216 * The difference between this method and {@link #getAnnotation(Class)} 217 * is that this method detects if its argument is a <em>repeatable 218 * annotation type</em> (JLS 9.6), and if so, attempts to find one or 219 * more annotations of that type by "looking through" a container 220 * annotation. 221 * 222 * The caller of this method is free to modify the returned array; it will 223 * have no effect on the arrays returned to other callers. 224 * 225 * @param <T> the type of the annotation to query for and return if present 226 * @param annotationClass the Class object corresponding to the 227 * annotation type 228 * @return all this element's annotations for the specified annotation type if 229 * associated with this element, else an array of length zero 230 * @throws NullPointerException if the given annotation class is null 231 * @since 1.8 232 */ 233 <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass); 234 235 /** 236 * Returns this element's annotation for the specified type if 237 * such an annotation is <em>directly present</em>, else null. 238 * 239 * This method ignores inherited annotations. (Returns null if no 240 * annotations are directly present on this element.) 241 * 242 * @param <T> the type of the annotation to query for and return if directly present 243 * @param annotationClass the Class object corresponding to the 244 * annotation type 245 * @return this element's annotation for the specified annotation type if 246 * directly present on this element, else null 247 * @throws NullPointerException if the given annotation class is null 248 * @since 1.8 249 */ 250 <T extends Annotation> T getDeclaredAnnotation(Class<T> annotationClass); 251 252 /** 253 * Returns this element's annotation(s) for the specified type if 254 * such annotations are either <em>directly present</em> or 255 * <em>indirectly present</em>. This method ignores inherited 256 * annotations. 257 * 258 * If there are no specified annotations directly or indirectly 259 * present on this element, the return value is an array of length 260 * 0. 261 * 262 * The difference between this method and {@link 263 * #getDeclaredAnnotation(Class)} is that this method detects if its 264 * argument is a <em>repeatable annotation type</em> (JLS 9.6), and if so, 265 * attempts to find one or more annotations of that type by "looking 266 * through" a container annotation if one is present. 267 * 268 * The caller of this method is free to modify the returned array; it will 269 * have no effect on the arrays returned to other callers. 270 * 271 * @param <T> the type of the annotation to query for and return 272 * if directly or indirectly present 273 * @param annotationClass the Class object corresponding to the 274 * annotation type 275 * @return all this element's annotations for the specified annotation type if 276 * directly or indirectly present on this element, else an array of length zero 277 * @throws NullPointerException if the given annotation class is null 278 * @since 1.8 279 */ 280 <T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass); 281 282 /** 283 * Returns annotations that are <em>directly present</em> on this element. 284 * This method ignores inherited annotations. 285 * 286 * If there are no annotations <em>directly present</em> on this element, 287 * the return value is an array of length 0. 288 * 289 * The caller of this method is free to modify the returned array; it will 290 * have no effect on the arrays returned to other callers. 291 * 292 * @return annotations directly present on this element 293 * @since 1.5 294 */ 295 Annotation[] getDeclaredAnnotations(); 296 } | 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.Annotation; 29 import java.lang.annotation.AnnotationFormatError; 30 import java.lang.annotation.Repeatable; 31 import java.util.Arrays; 32 import java.util.LinkedHashMap; 33 import java.util.Map; 34 import java.util.Objects; 35 import java.util.function.Function; 36 import java.util.stream.Collectors; 37 import sun.reflect.annotation.AnnotationSupport; 38 import sun.reflect.annotation.AnnotationType; 39 40 /** 41 * Represents an annotated element of the program currently running in this 42 * VM. This interface allows annotations to be read reflectively. All 43 * annotations returned by methods in this interface are immutable and 44 * serializable. The arrays returned by methods of this interface may be modified 45 * by callers without affecting the arrays returned to other callers. 46 * 47 * <p>The {@link #getAnnotationsByType(Class)} and {@link 48 * #getDeclaredAnnotationsByType(Class)} methods support multiple 49 * annotations of the same type on an element. If the argument to 50 * either method is a repeatable annotation type (JLS 9.6), then the 51 * method will "look through" a container annotation (JLS 9.7), if 52 * present, and return any annotations inside the container. Container 53 * annotations may be generated at compile-time to wrap multiple 54 * annotations of the argument type. 55 * 56 * <p>The terms <em>directly present</em>, <em>indirectly present</em>, 57 * <em>present</em>, and <em>associated</em> are used throughout this 58 * interface to describe precisely which annotations are returned by 214 * @return annotations present on this element 215 * @since 1.5 216 */ 217 Annotation[] getAnnotations(); 218 219 /** 220 * Returns annotations that are <em>associated</em> with this element. 221 * 222 * If there are no annotations <em>associated</em> with this element, the return 223 * value is an array of length 0. 224 * 225 * The difference between this method and {@link #getAnnotation(Class)} 226 * is that this method detects if its argument is a <em>repeatable 227 * annotation type</em> (JLS 9.6), and if so, attempts to find one or 228 * more annotations of that type by "looking through" a container 229 * annotation. 230 * 231 * The caller of this method is free to modify the returned array; it will 232 * have no effect on the arrays returned to other callers. 233 * 234 * @implSpec The default implementation first calls {@link 235 * #getDeclaredAnnotationsByType(Class)} passing {@code 236 * annotationClass} as the argument. If the returned array has 237 * size greater than zero, the array is returned. If the returned 238 * array has size zero and this {@code AnnotatedElement} is a 239 * class and the argument type is an inheritable annotation type, 240 * and the superclass of this {@code AnnoatedElement} is non-null, 241 * then the returned result is the result of calling {@code 242 * getAnnotationsByType} on the superclass with {@code 243 * annotationClass} as the argument. Otherwise, a zero-length 244 * array is returned. 245 * 246 * @param <T> the type of the annotation to query for and return if present 247 * @param annotationClass the Class object corresponding to the 248 * annotation type 249 * @return all this element's annotations for the specified annotation type if 250 * associated with this element, else an array of length zero 251 * @throws NullPointerException if the given annotation class is null 252 * @since 1.8 253 */ 254 default <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass) { 255 /* 256 * Definition of associated: directly or indirectly present OR 257 * neither directly nor indirectly present AND the element is 258 * a Class, the annotation type is inheritable, and the 259 * annotation type is associated with the superclass of the 260 * element. 261 */ 262 T[] result = getDeclaredAnnotationsByType(annotationClass); 263 264 if (result.length == 0 && // Neither directly nor indirectly present 265 this instanceof Class && // the element is a class 266 AnnotationType.getInstance(annotationClass).isInherited()) { // Inheritable 267 Class<?> superClass = ((Class<?>) this).getSuperclass(); 268 if (superClass != null) { 269 // Determine if the annotation is associated with the 270 // superclass 271 result = superClass.getAnnotationsByType(annotationClass); 272 } 273 } 274 275 return result; 276 } 277 278 /** 279 * Returns this element's annotation for the specified type if 280 * such an annotation is <em>directly present</em>, else null. 281 * 282 * This method ignores inherited annotations. (Returns null if no 283 * annotations are directly present on this element.) 284 * 285 * @implSpec The default implementation first performs a null check 286 * and then loops over the results of {@link 287 * #getDeclaredAnnotations} returning the first annotation whose 288 * annotation type matches the argument type. 289 * 290 * @param <T> the type of the annotation to query for and return if directly present 291 * @param annotationClass the Class object corresponding to the 292 * annotation type 293 * @return this element's annotation for the specified annotation type if 294 * directly present on this element, else null 295 * @throws NullPointerException if the given annotation class is null 296 * @since 1.8 297 */ 298 default <T extends Annotation> T getDeclaredAnnotation(Class<T> annotationClass) { 299 Objects.requireNonNull(annotationClass); 300 // Loop over all directly-present annotations looking for a matching one 301 for (Annotation annotation : getDeclaredAnnotations()) { 302 if (annotationClass.equals(annotation.annotationType())) { 303 // More robust to do a dynamic cast at runtime instead 304 // of compile-time only. 305 return annotationClass.cast(annotation); 306 } 307 } 308 return null; 309 } 310 311 /** 312 * Returns this element's annotation(s) for the specified type if 313 * such annotations are either <em>directly present</em> or 314 * <em>indirectly present</em>. This method ignores inherited 315 * annotations. 316 * 317 * If there are no specified annotations directly or indirectly 318 * present on this element, the return value is an array of length 319 * 0. 320 * 321 * The difference between this method and {@link 322 * #getDeclaredAnnotation(Class)} is that this method detects if its 323 * argument is a <em>repeatable annotation type</em> (JLS 9.6), and if so, 324 * attempts to find one or more annotations of that type by "looking 325 * through" a container annotation if one is present. 326 * 327 * The caller of this method is free to modify the returned array; it will 328 * have no effect on the arrays returned to other callers. 329 * 330 * @implSpec The default implementation may call {@link 331 * #getDeclaredAnnotation(Class)} one or more times to find a 332 * directly present annotation and, if the annotation type is 333 * repeatable, to find a container annotation. If annotations of 334 * the annotation type {@code annotationClass} are found to be both 335 * directly and indirectly present, then {@link 336 * #getDeclaredAnnotations()} will get called to determine the 337 * order of the elements in the returned array. 338 * 339 * <p>Alternatively, the default implementation may call {@link 340 * #getDeclaredAnnotations()} a single time and the returned array 341 * examined for both directly and indirectly present 342 * annotations. The results of calling {@link 343 * #getDeclaredAnnotations()} are assumed to be consistent with the 344 * results of calling {@link #getDeclaredAnnotation(Class)}. 345 * 346 * @param <T> the type of the annotation to query for and return 347 * if directly or indirectly present 348 * @param annotationClass the Class object corresponding to the 349 * annotation type 350 * @return all this element's annotations for the specified annotation type if 351 * directly or indirectly present on this element, else an array of length zero 352 * @throws NullPointerException if the given annotation class is null 353 * @since 1.8 354 */ 355 default <T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass) { 356 Objects.requireNonNull(annotationClass); 357 return AnnotationSupport. 358 getDirectlyAndIndirectlyPresent(Arrays.stream(getDeclaredAnnotations()). 359 collect(Collectors.toMap(Annotation::annotationType, 360 Function.identity(), 361 ((first,second) -> first), 362 LinkedHashMap::new)), 363 annotationClass); 364 } 365 366 367 /** 368 * Returns annotations that are <em>directly present</em> on this element. 369 * This method ignores inherited annotations. 370 * 371 * If there are no annotations <em>directly present</em> on this element, 372 * the return value is an array of length 0. 373 * 374 * The caller of this method is free to modify the returned array; it will 375 * have no effect on the arrays returned to other callers. 376 * 377 * @return annotations directly present on this element 378 * @since 1.5 379 */ 380 Annotation[] getDeclaredAnnotations(); 381 } |