org.apache.commons.collections.functors
Class ConstantFactory<T>

java.lang.Object
  org.apache.commons.collections.functors.ConstantFactory<T>

All Implemented Interfaces:

Serializable, Factory<T>

public class ConstantFactory<T>
extends Object
implements Factory<T>, Serializable

Factory implementation that returns the same constant each time.

No check is made that the object is immutable. In general, only immutable objects should use the constant factory. Mutable objects should use the prototype factory.

Since:

Commons Collections 3.0

Version:

$Revision: 1.1.1.1 $ $Date: 2005/05/23 04:34:16 $

Author:

Matt Hall, John Watkinson, Stephen Colebourne

See Also:

Serialized Form

Field Summary

static Factory

NULL_INSTANCE Returns null each time

Constructor Summary

ConstantFactory(T constantToReturn)
Constructor that performs no validation.

Method Summary

T	create() Always return constant.
T	getConstant() Gets the constant.
static <T> Factory<T>	getInstance(T constantToReturn) Factory method that performs validation.

Methods inherited from class java.lang.Object

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

Field Detail

NULL_INSTANCE

public static final Factory NULL_INSTANCE

Returns null each time

Constructor Detail

ConstantFactory

public ConstantFactory(T constantToReturn)

Constructor that performs no validation. Use getInstance if you want that.

Parameters:

constantToReturn - the constant to return each time

Method Detail

getInstance

public static <T> Factory<T> getInstance(T constantToReturn)

Factory method that performs validation.

Parameters:

constantToReturn - the constant object to return each time in the factory

Returns:

the constant factory.

create

public T create()

Always return constant.

Specified by:

create in interface Factory<T>

Returns:

the stored constant value

getConstant

public T getConstant()

Gets the constant.

Returns:

the constant

Since:

Commons Collections 3.1