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

  *

  * This code is free software; you can redistribute it and/or modify it

  * 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 common interface extended by all annotation types.  Note that an

  * interface that manually extends this one does <i>not</i> define

  * an annotation type.  Also note that this interface does not itself

  * define an annotation type.

  *

  * More information about annotation types can be found in section 9.6 of

  * <cite>The Java&trade; Language Specification</cite>.

  *

  * @author  Josh Bloch

  * @since   1.5

  */

 public interface Annotation {

     /**

      * Returns true if the specified object represents an annotation

      * that is logically equivalent to this one.  In other words,

      * returns true if the specified object is an instance of the same

      * annotation type as this instance, all of whose members are equal

      * to the corresponding member of this annotation, as defined below:

      * <ul>

      *    <li>Two corresponding primitive typed members whose values are

      *    <tt>x</tt> and <tt>y</tt> are considered equal if <tt>x == y</tt>,

      *    unless their type is <tt>float</tt> or <tt>double</tt>.

      *

      *    <li>Two corresponding <tt>float</tt> members whose values

      *    are <tt>x</tt> and <tt>y</tt> are considered equal if

      *    <tt>Float.valueOf(x).equals(Float.valueOf(y))</tt>.

      *    (Unlike the <tt>==</tt> operator, NaN is considered equal

      *    to itself, and <tt>0.0f</tt> unequal to <tt>-0.0f</tt>.)

      *

      *    <li>Two corresponding <tt>double</tt> members whose values

      *    are <tt>x</tt> and <tt>y</tt> are considered equal if

      *    <tt>Double.valueOf(x).equals(Double.valueOf(y))</tt>.

      *    (Unlike the <tt>==</tt> operator, NaN is considered equal

      *    to itself, and <tt>0.0</tt> unequal to <tt>-0.0</tt>.)

      *

      *    <li>Two corresponding <tt>String</tt>, <tt>Class</tt>, enum, or

      *    annotation typed members whose values are <tt>x</tt> and <tt>y</tt>

      *    are considered equal if <tt>x.equals(y)</tt>.  (Note that this

      *    definition is recursive for annotation typed members.)

      *

      *    <li>Two corresponding array typed members <tt>x</tt> and <tt>y</tt>

      *    are considered equal if <tt>Arrays.equals(x, y)</tt>, for the

      *    appropriate overloading of {@link java.util.Arrays#equals}.

      * </ul>

      *

      * @return true if the specified object represents an annotation

      *     that is logically equivalent to this one, otherwise false

      */

     boolean equals(Object obj);

     /**

      * Returns the hash code of this annotation, as defined below:

      *

      * <p>The hash code of an annotation is the sum of the hash codes

      * of its members (including those with default values), as defined

      * below:

      *

      * The hash code of an annotation member is (127 times the hash code

      * of the member-name as computed by {@link String#hashCode()}) XOR

      * the hash code of the member-value, as defined below:

      *

      * <p>The hash code of a member-value depends on its type:

      * <ul>

      * <li>The hash code of a primitive value <tt><i>v</i></tt> is equal to

      *     <tt><i>WrapperType</i>.valueOf(<i>v</i>).hashCode()</tt>, where

      *     <tt><i>WrapperType</i></tt> is the wrapper type corresponding

      *     to the primitive type of <tt><i>v</i></tt> ({@link Byte},

      *     {@link Character}, {@link Double}, {@link Float}, {@link Integer},

      *     {@link Long}, {@link Short}, or {@link Boolean}).

      *

      * <li>The hash code of a string, enum, class, or annotation member-value

      I     <tt><i>v</i></tt> is computed as by calling

      *     <tt><i>v</i>.hashCode()</tt>.  (In the case of annotation

      *     member values, this is a recursive definition.)

      *

      * <li>The hash code of an array member-value is computed by calling

      *     the appropriate overloading of

      *     {@link java.util.Arrays#hashCode(long[]) Arrays.hashCode}

      *     on the value.  (There is one overloading for each primitive

      *     type, and one for object reference types.)

      * </ul>

      *

      * @return the hash code of this annotation

      */

     int hashCode();

     /**

      * Returns a string representation of this annotation.  The details

      * of the representation are implementation-dependent, but the following

      * may be regarded as typical:

      * <pre>

      *   @com.acme.util.Name(first=Alfred, middle=E., last=Neuman)

      * </pre>

      *

      * @return a string representation of this annotation

      */

     String toString();

     /**

      * Returns the annotation type of this annotation.

      */

     Class<? extends Annotation> annotationType();

 }