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.annotation;
27
28 /**
29 * Indicates the kinds of program element to which an annotation type
30 * is applicable. If a Target meta-annotation is not present on an
31 * annotation type declaration, the declared type may be used on any
32 * program element. If such a meta-annotation is present, the compiler
33 * will enforce the specified usage restriction.
34 *
35 * For example, this meta-annotation indicates that the declared type is
36 * itself a meta-annotation type. It can only be used on annotation type
37 * declarations:
38 * <pre>
39 * @Target(ElementType.ANNOTATION_TYPE)
40 * public @interface MetaAnnotationType {
41 * ...
42 * }
43 * </pre>
44 * This meta-annotation indicates that the declared type is intended solely
45 * for use as a member type in complex annotation type declarations. It
46 * cannot be used to annotate anything directly:
47 * <pre>
48 * @Target({})
49 * public @interface MemberType {
50 * ...
51 * }
52 * </pre>
53 * It is a compile-time error for a single ElementType constant to
54 * appear more than once in a Target annotation. For example, the
55 * following meta-annotation is illegal:
56 * <pre>
57 * @Target({ElementType.FIELD, ElementType.METHOD, ElementType.FIELD})
58 * public @interface Bogus {
59 * ...
60 * }
61 * </pre>
62 *
63 * @since 1.5
64 * @jls 9.6.3.1 @Target
65 */
66 @Documented
67 @Retention(RetentionPolicy.RUNTIME)
68 @Target(ElementType.ANNOTATION_TYPE)
69 public @interface Target {
70 /**
71 * Returns an array of the kinds of elements an annotation type
72 * can be applied to.
73 * @return an array of the kinds of elements an annotation type
74 * can be applied to
75 */
76 ElementType[] value();
77 }
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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.annotation;
27
28 /**
29 * Indicates the contexts in which an annotation type is applicable. The
30 * declaration contexts and type contexts in which an annotation type may be
31 * applicable are specified in JLS 9.6.4.1, and denoted in source code by enum
32 * constants of {@link ElementType java.lang.annotation.ElementType}.
33 *
34 * <p>If an {@code @Target} meta-annotation is not present on an annotation type
35 * {@code T} , then an annotation of type {@code T} may be written as a
36 * modifier for any declaration except a type parameter declaration.
37 *
38 * <p>If an {@code @Target} meta-annotation is present, the compiler will enforce
39 * the usage restrictions indicated by {@code ElementType}
40 * enum constants, in line with JLS 9.7.4.
41 *
42 * <p>For example, this {@code @Target} meta-annotation indicates that the
43 * declared type is itself a meta-annotation type. It can only be used on
44 * annotation type declarations:
45 * <pre>
46 * @Target(ElementType.ANNOTATION_TYPE)
47 * public @interface MetaAnnotationType {
48 * ...
49 * }
50 * </pre>
51 *
52 * <p>This {@code @Target} meta-annotation indicates that the declared type is
53 * intended solely for use as a member type in complex annotation type
54 * declarations. It cannot be used to annotate anything directly:
55 * <pre>
56 * @Target({})
57 * public @interface MemberType {
58 * ...
59 * }
60 * </pre>
61 *
62 * <p>It is a compile-time error for a single {@code ElementType} constant to
63 * appear more than once in an {@code @Target} annotation. For example, the
64 * following {@code @Target} meta-annotation is illegal:
65 * <pre>
66 * @Target({ElementType.FIELD, ElementType.METHOD, ElementType.FIELD})
67 * public @interface Bogus {
68 * ...
69 * }
70 * </pre>
71 *
72 * @since 1.5
73 * @jls 9.6.4.1 @Target
74 * @jls 9.7.4 Where Annotations May Appear
75 */
76 @Documented
77 @Retention(RetentionPolicy.RUNTIME)
78 @Target(ElementType.ANNOTATION_TYPE)
79 public @interface Target {
80 /**
81 * Returns an array of the kinds of elements an annotation type
82 * can be applied to.
83 * @return an array of the kinds of elements an annotation type
84 * can be applied to
85 */
86 ElementType[] value();
87 }
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