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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package java.lang.annotation;

/**

 * The constants of this enumerated type provide a simple classification of the

 * syntactic locations where annotations may appear in a Java program. These

 * constants are used in {@link java.lang.annotation.Target Target}

 * meta-annotations to specify where it is legal to write annotations of a

 * given type.

 *

 * <p>The syntactic locations where annotations may appear are split into

 * <em>declaration contexts</em> , where annotations apply to declarations, and

 * <em>type contexts</em> , where annotations apply to types used in

 * declarations and expressions.

 *

 * <p>The constants {@link #ANNOTATION_TYPE}, {@link #CONSTRUCTOR}, {@link

 * #FIELD}, {@link #LOCAL_VARIABLE}, {@link #METHOD}, {@link #PACKAGE}, {@link

 * #MODULE}, {@link #PARAMETER}, {@link #TYPE}, and {@link #TYPE_PARAMETER}

 * correspond to the declaration contexts in JLS 9.6.4.1.

 *

 * <p>For example, an annotation whose type is meta-annotated with

 * {@code @Target(ElementType.FIELD)} may only be written as a modifier for a

 * field declaration.

 *

 * <p>The constant {@link #TYPE_USE} corresponds to the type contexts in JLS

 * 4.11, as well as to two declaration contexts: type declarations (including

 * annotation type declarations) and type parameter declarations.

 *

 * <p>For example, an annotation whose type is meta-annotated with

 * {@code @Target(ElementType.TYPE_USE)} may be written on the type of a field

 * (or within the type of the field, if it is a nested, parameterized, or array

 * type), and may also appear as a modifier for, say, a class declaration.

 *

 * <p>The {@code TYPE_USE} constant includes type declarations and type

 * parameter declarations as a convenience for designers of type checkers which

 * give semantics to annotation types. For example, if the annotation type

 * {@code NonNull} is meta-annotated with

 * {@code @Target(ElementType.TYPE_USE)}, then {@code @NonNull}

 * {@code class C {...}} could be treated by a type checker as indicating that

 * all variables of class {@code C} are non-null, while still allowing

 * variables of other classes to be non-null or not non-null based on whether

 * {@code @NonNull} appears at the variable's declaration.

 *

 * @author  Joshua Bloch

 * @since 1.5

 * @jls 9.6.4.1 @Target

 * @jls 4.1 The Kinds of Types and Values

 */

public enum ElementType {

    /** Class, interface (including annotation type), or enum declaration */

    TYPE,

    /** Field declaration (includes enum constants) */

    FIELD,

    /** Method declaration */

    METHOD,

    /** Formal parameter declaration */

    PARAMETER,

    /** Constructor declaration */

    CONSTRUCTOR,

    /** Local variable declaration */

    LOCAL_VARIABLE,

    /** Annotation type declaration */

    ANNOTATION_TYPE,

    /** Package declaration */

    PACKAGE,

    /**

     * Type parameter declaration

     *

     * @since 1.8

     */

    TYPE_PARAMETER,

    /**

     * Use of a type

     *

     * @since 1.8

     */

    TYPE_USE,

    /**

     * Module declaration.

     *

     * @since 9

     */

    MODULE

}