org.infinispan.commons.equivalence

Interface Equivalence<T>

All Superinterfaces:

Serializable

All Known Implementing Classes:

AnyEquivalence, AnyServerEquivalence, ByteArrayEquivalence, IdentityEquivalence

public interface Equivalence<T>
extends Serializable

An interface that allows custom implementations for objects that are comparable based on equality, hash code calculations, or according to Comparable rules, but where the behaviour provided by the JDK, or external libraries, cannot be modified, for example: arrays. The interface is marked to be Serializable because multiple collection extensions within the Infinispan code base contain references to them, and since these are potentially Serializable, they might be persisted somehow.

Since:

5.3

Author:

Galder Zamarreño

Method Summary

Modifier and Type	Method and Description
int	compare(T obj, T otherObj) Compares the two given objects for order.
boolean	equals(T obj, Object otherObj) Indicates whether the objects passed are "equal to" each other.
int	hashCode(Object obj) Returns a hash code value for the object passed.
boolean	isComparable(Object obj) Returns whether the given object is comparable.
String	toString(Object obj) Returns a string representation of the given object.

Method Detail

hashCode

int hashCode(Object obj)

Returns a hash code value for the object passed. As an example, implementors can provide an alternative implementation for the hash code calculation for arrays. So, instead of relying on Object.hashCode(), call java.util.Arrays.hashCode().

Parameters:

obj - instance to calculate hash code for

Returns:

a hash code value for the object passed as parameter

equals

boolean equals(T obj,
               Object otherObj)

Indicates whether the objects passed are "equal to" each other. As an example, implementors can provide an alternative implementation for the equals for arrays. So, instead of relying on Object.equals(Object)}, call java.util.Arrays.equals()).

Parameters:

obj - to be compared with second parameter

otherObj - to be compared with first parameter

Returns:

true if both objects are the same; false otherwise

toString

String toString(Object obj)

Returns a string representation of the given object.

Parameters:

obj - whose string representation is to be returned

Returns:

a string representation of the passed object

isComparable

boolean isComparable(Object obj)

Returns whether the given object is comparable. In other words, if given an instance of the object, a sensible comparison can be computed using compare(Object, Object) method.

Parameters:

obj - instance to check if it's comparable

Returns:

true if the object is comparable; false otherwise

compare

int compare(T obj,
            T otherObj)

Compares the two given objects for order. Returns a negative integer, zero, or a positive integer as the first object is less than, equal to, or greater than the second object.

Parameters:

obj - first object to be compared

otherObj - second object to be compared

Returns:

a negative integer, zero, or a positive integer as the first object is less than, equal to, or greater than the second object