Package org.apache.commons.collections4.functors

Class DefaultEquator<T>

java.lang.Object

org.apache.commons.collections4.functors.DefaultEquator<T>

Type Parameters:

T - the types of object this Equator can evaluate.

All Implemented Interfaces:

Serializable, Equator<T>

public class DefaultEquator<T>
extends Object
implements Equator<T>, Serializable

Default Equator implementation.

Since:

4.0

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final int	HASHCODE_NULL	Hashcode used for null objects.
static final DefaultEquator	INSTANCE	Static instance

Method Summary

Modifier and Type	Method	Description
static <T> DefaultEquator<T>	defaultEquator()	Factory returning the typed singleton instance.
boolean	equate(T o1, T o2)	Evaluates the two arguments for their equality.
int	hash(T o)	Calculates the hash for the object, based on the method of equality used in the equate method.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

INSTANCE

public static final DefaultEquator INSTANCE

Static instance

HASHCODE_NULL

public static final int HASHCODE_NULL

Hashcode used for null objects.

See Also:

• Constant Field Values

Method Details

defaultEquator

public static <T> DefaultEquator<T> defaultEquator()

Factory returning the typed singleton instance.

Type Parameters:

T - the object type

Returns:

the singleton instance

equate

public boolean equate(T o1,
 T o2)

Evaluates the two arguments for their equality. Delegates to Objects.equals(Object, Object).

Specified by:

equate in interface Equator<T>

Parameters:

o1 - the first object to be equated.

o2 - the second object to be equated.

Returns:

whether the two objects are equal.

hash

public int hash(T o)

Calculates the hash for the object, based on the method of equality used in the equate method. This is used for classes that delegate their equals(Object) method to an Equator (and so must also delegate their hashCode() method), or for implementations of HashedMap that use an Equator for the key objects.

Specified by:

hash in interface Equator<T>

Parameters:

o - the object to calculate the hash for.

Returns:

o.hashCode() if o is non- null, else HASHCODE_NULL.