- 001
/* - 002
* @(#)Annotation.java 1.10 05/11/17 - 003 *
- 004 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
- 005 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- 006
*/ - 007
- 008package java.lang.annotation;
- 009
- 010/**
- 011 * The common interface extended by all annotation types. Note that an
- 012 * interface that manually extends this one does <i>not</i> define
- 013 * an annotation type. Also note that this interface does not itself
- 014 * define an annotation type.
- 015 *
- 016 * @author Josh Bloch
- 017 * @since 1.5
- 018 */
- 019public interface Annotation {
- 020 /**
- 021 * Returns true if the specified object represents an annotation
- 022 * that is logically equivalent to this one. In other words,
- 023 * returns true if the specified object is an instance of the same
- 024 * annotation type as this instance, all of whose members are equal
- 025 * to the corresponding member of this annotation, as defined below:
- 026 * <ul>
- 027 * <li>Two corresponding primitive typed members whose values are
- 028 * <tt>x</tt> and <tt>y</tt> are considered equal if <tt>x == y</tt>,
- 029 * unless their type is <tt>float</tt> or <tt>double</tt>.
- 030 *
- 031 * <li>Two corresponding <tt>float</tt> members whose values
- 032 * are <tt>x</tt> and <tt>y</tt> are considered equal if
- 033 * <tt>Float.valueOf(x).equals(Float.valueOf(y))</tt>.
- 034 * (Unlike the <tt>==</tt> operator, NaN is considered equal
- 035 * to itself, and <tt>0.0f</tt> unequal to <tt>-0.0f</tt>.)
- 036 *
- 037 * <li>Two corresponding <tt>double</tt> members whose values
- 038 * are <tt>x</tt> and <tt>y</tt> are considered equal if
- 039 * <tt>Double.valueOf(x).equals(Double.valueOf(y))</tt>.
- 040 * (Unlike the <tt>==</tt> operator, NaN is considered equal
- 041 * to itself, and <tt>0.0</tt> unequal to <tt>-0.0</tt>.)
- 042 *
- 043 * <li>Two corresponding <tt>String</tt>, <tt>Class</tt>, enum, or
- 044 * annotation typed members whose values are <tt>x</tt> and <tt>y</tt>
- 045 * are considered equal if <tt>x.equals(y)</tt>. (Note that this
- 046 * definition is recursive for annotation typed members.)
- 047 *
- 048 * <li>Two corresponding array typed members <tt>x</tt> and <tt>y</tt>
- 049 * are considered equal if <tt>Arrays.equals(x, y)</tt>, for the
- 050 * appropriate overloading of {@link java.util.Arrays#equals}.
- 051 * </ul>
- 052 *
- 053 * @return true if the specified object represents an annotation
- 054 * that is logically equivalent to this one, otherwise false
- 055 */
- 056 boolean equals(Object obj);
- 057
- 058 /**
- 059 * Returns the hash code of this annotation, as defined below:
- 060 *
- 061 * <p>The hash code of an annotation is the sum of the hash codes
- 062 * of its members (including those with default values), as defined
- 063 * below:
- 064 *
- 065 * The hash code of an annotation member is (127 times the hash code
- 066 * of the member-name as computed by {@link String#hashCode()}) XOR
- 067 * the hash code of the member-value, as defined below:
- 068 *
- 069 * <p>The hash code of a member-value depends on its type:
- 070 * <ul>
- 071 * <li>The hash code of a primitive value <tt><i>v</i></tt> is equal to
- 072 * <tt><i>WrapperType</i>.valueOf(<i>v</i>).hashCode()</tt>, where
- 073 * <tt><i>WrapperType</i></tt> is the wrapper type corresponding
- 074 * to the primitive type of <tt><i>v</i></tt> ({@link Byte},
- 075 * {@link Character}, {@link Double}, {@link Float}, {@link Integer},
- 076 * {@link Long}, {@link Short}, or {@link Boolean}).
- 077 *
- 078 * <li>The hash code of a string, enum, class, or annotation member-value
- 079 I <tt><i>v</i></tt> is computed as by calling
- 080 * <tt><i>v</i>.hashCode()</tt>. (In the case of annotation
- 081 * member values, this is a recursive definition.)
- 082 *
- 083 * <li>The hash code of an array member-value is computed by calling
- 084 * the appropriate overloading of
- 085 * {@link java.util.Arrays#hashCode(long[]) Arrays.hashCode}
- 086 * on the value. (There is one overloading for each primitive
- 087 * type, and one for object reference types.)
- 088 * </ul>
- 089 *
- 090 * @return the hash code of this annotation
- 091 */
- 092 int hashCode();
- 093
- 094 /**
- 095 * Returns a string representation of this annotation. The details
- 096 * of the representation are implementation-dependent, but the following
- 097 * may be regarded as typical:
- 098 * <pre>
- 099 * @com.acme.util.Name(first=Alfred, middle=E., last=Neuman)
- 100 * </pre>
- 101 *
- 102 * @return a string representation of this annotation
- 103 */
- 104 String toString();
- 105
- 106 /**
- 107 * Returns the annotation type of this annotation.
- 108 */
- 109 Class<? extends Annotation> annotationType();
- 110}
