| /* |
| * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. |
| * 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 |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| 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™ Language Specification</cite>. |
| * |
| * The {@link java.lang.reflect.AnnotatedElement} interface discusses |
| * compatibility concerns when evolving an annotation type from being |
| * non-repeatable to being repeatable. |
| * |
| * @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 |
| * {@code x} and {@code y} are considered equal if {@code x == y}, |
| * unless their type is {@code float} or {@code double}. |
| * |
| * <li>Two corresponding {@code float} members whose values |
| * are {@code x} and {@code y} are considered equal if |
| * {@code Float.valueOf(x).equals(Float.valueOf(y))}. |
| * (Unlike the {@code ==} operator, NaN is considered equal |
| * to itself, and {@code 0.0f} unequal to {@code -0.0f}.) |
| * |
| * <li>Two corresponding {@code double} members whose values |
| * are {@code x} and {@code y} are considered equal if |
| * {@code Double.valueOf(x).equals(Double.valueOf(y))}. |
| * (Unlike the {@code ==} operator, NaN is considered equal |
| * to itself, and {@code 0.0} unequal to {@code -0.0}.) |
| * |
| * <li>Two corresponding {@code String}, {@code Class}, enum, or |
| * annotation typed members whose values are {@code x} and {@code y} |
| * are considered equal if {@code x.equals(y)}. (Note that this |
| * definition is recursive for annotation typed members.) |
| * |
| * <li>Two corresponding array typed members {@code x} and {@code y} |
| * are considered equal if {@code Arrays.equals(x, y)}, 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 <i>{@code v}</i> is equal to |
| * <code><i>WrapperType</i>.valueOf(<i>v</i>).hashCode()</code>, where |
| * <i>{@code WrapperType}</i> is the wrapper type corresponding |
| * to the primitive type of <i>{@code v}</i> ({@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 <i>{@code v}</i> is computed as by calling |
| * <code><i>v</i>.hashCode()</code>. (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. |
| * @return the annotation type of this annotation |
| */ |
| Class<? extends Annotation> annotationType(); |
| } |