java.lang.annotation.Annotation Maven / Gradle / Ivy
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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 not 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
* The Java™ Language Specification.
*
* @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:
*
* - Two corresponding primitive typed members whose values are
* x and y are considered equal if x == y,
* unless their type is float or double.
*
*
- Two corresponding float members whose values
* are x and y are considered equal if
* Float.valueOf(x).equals(Float.valueOf(y)).
* (Unlike the == operator, NaN is considered equal
* to itself, and 0.0f unequal to -0.0f.)
*
*
- Two corresponding double members whose values
* are x and y are considered equal if
* Double.valueOf(x).equals(Double.valueOf(y)).
* (Unlike the == operator, NaN is considered equal
* to itself, and 0.0 unequal to -0.0.)
*
*
- Two corresponding String, Class, enum, or
* annotation typed members whose values are x and y
* are considered equal if x.equals(y). (Note that this
* definition is recursive for annotation typed members.)
*
*
- Two corresponding array typed members x and y
* are considered equal if Arrays.equals(x, y), for the
* appropriate overloading of {@link java.util.Arrays#equals}.
*
*
* @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:
*
* 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:
*
*
The hash code of a member-value depends on its type:
*
* - The hash code of a primitive value v is equal to
* WrapperType.valueOf(v).hashCode(), where
* WrapperType is the wrapper type corresponding
* to the primitive type of v ({@link Byte},
* {@link Character}, {@link Double}, {@link Float}, {@link Integer},
* {@link Long}, {@link Short}, or {@link Boolean}).
*
*
- The hash code of a string, enum, class, or annotation member-value
I v is computed as by calling
* v.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
* {@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.)
*
*
* @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:
*
* @com.acme.util.Name(first=Alfred, middle=E., last=Neuman)
*
*
* @return a string representation of this annotation
*/
String toString();
/**
* Returns the annotation type of this annotation.
*/
Class annotationType();
}