jdk/src/java.base/share/classes/java/lang/annotation/Annotation.java
changeset 25859 3317bb8137f4
parent 22080 18a23ba7dd38
child 32033 bf24e33c7919
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/java/lang/annotation/Annotation.java	Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,136 @@
+/*
+ * 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&trade; 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
+     *    <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>
+     *   &#064;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();
+}