org.apache.commons.collections.functors
Class ConstantFactory

java.lang.Object
  org.apache.commons.collections.functors.ConstantFactory

All Implemented Interfaces:

java.io.Serializable, Factory

public class ConstantFactory
extends java.lang.Object
implements Factory, java.io.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: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $

Author:

Stephen Colebourne

See Also:

Serialized Form

Field Summary

static Factory

NULL_INSTANCE Returns null each time

Constructor Summary

ConstantFactory(java.lang.Object constantToReturn)
Constructor that performs no validation.

Method Summary

java.lang.Object	create() Always return constant.
java.lang.Object	getConstant() Gets the constant.
static Factory	getInstance(java.lang.Object 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(java.lang.Object 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 Factory getInstance(java.lang.Object constantToReturn)

Factory method that performs validation.

Parameters:

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

Returns:

the constant factory.

create

public java.lang.Object create()

Always return constant.

Specified by:

create in interface Factory

Returns:

the stored constant value

getConstant

public java.lang.Object getConstant()

Gets the constant.

Returns:

the constant

Since:

Commons Collections 3.1