Annotation
public
interface
Annotation
java.lang.annotation.Annotation |
The common interface extended by all annotation interfaces. Note that an
interface that manually extends this one does not define
an annotation interface. Also note that this interface does not itself
define an annotation interface.
More information about annotation interfaces can be found in section
{@jls 9.6} of The Java Language Specification.
The AnnotatedElement
interface discusses
compatibility concerns when evolving an annotation interface from being
non-repeatable to being repeatable.
Summary
Public methods | |
---|---|
abstract
Class<? extends Annotation>
|
annotationType()
Returns the annotation interface of this annotation. |
abstract
boolean
|
equals(Object obj)
Returns true if the specified object represents an annotation that is logically equivalent to this one. |
abstract
int
|
hashCode()
Returns the hash code of this annotation. |
abstract
String
|
toString()
Returns a string representation of this annotation. |
Public methods
annotationType
public abstract Class<? extends Annotation> annotationType ()
Returns the annotation interface of this annotation.
API Note:
- Implementation-dependent classes are used to provide
the implementations of annotations. Therefore, calling
getClass
on an annotation will return an implementation-dependent class. In contrast, this method will reliably return the annotation interface of the annotation.
Returns | |
---|---|
Class<? extends Annotation> |
the annotation interface of this annotation |
See also:
equals
public abstract boolean equals (Object obj)
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 interface as this instance, all of whose members are equal to the corresponding member of this annotation, as defined below:
- Two corresponding primitive typed members whose values are
x
andy
are considered equal ifx == y
, unless their type isfloat
ordouble
. - Two corresponding
float
members whose values arex
andy
are considered equal ifFloat.valueOf(x).equals(Float.valueOf(y))
. (Unlike the==
operator, NaN is considered equal to itself, and0.0f
unequal to-0.0f
.) - Two corresponding
double
members whose values arex
andy
are considered equal ifDouble.valueOf(x).equals(Double.valueOf(y))
. (Unlike the==
operator, NaN is considered equal to itself, and0.0
unequal to-0.0
.) - Two corresponding
String
,Class
, enum, or annotation typed members whose values arex
andy
are considered equal ifx.equals(y)
. (Note that this definition is recursive for annotation typed members.) - Two corresponding array typed members
x
andy
are considered equal ifArrays.equals(x, y)
, for the appropriate overloading ofArrays.equals
.
Parameters | |
---|---|
obj |
Object |
Returns | |
---|---|
boolean |
true if the specified object represents an annotation that is logically equivalent to this one, otherwise false |
hashCode
public abstract int hashCode ()
Returns the hash code of this annotation.
The hash code of an annotation is the sum of the hash codes
of its members (including those with default values).
The hash code of an annotation member is (127 times the hash code
of the member-name as computed by String#hashCode()
) XOR
the hash code of the member-value.
The hash code of a member-value depends on its type as defined below:
- The hash code of a primitive value
v
is equal toWrapperType.valueOf(v).hashCode()
, whereWrapperType
is the wrapper type corresponding to the primitive type ofv
(Byte
,Character
,Double
,Float
,Integer
,Long
,Short
, orBoolean
). - The hash code of a string, enum, class, or annotation member-value
v
is computed as by callingv.hashCode()
. (In the case of annotation member values, this is a recursive definition.) - The hash code of an array member-value is computed by calling
the appropriate overloading of
Arrays.hashCode
on the value. (There is one overloading for each primitive type, and one for object reference types.)
Returns | |
---|---|
int |
the hash code of this annotation |
toString
public abstract String toString ()
Returns a string representation of this annotation. The details of the representation are implementation-dependent, but the following may be regarded as typical:
@com.example.Name(first="Duke", middle="of", last="Java")
Returns | |
---|---|
String |
a string representation of this annotation |