org.apache.commons.collections.functors
Class ConstantFactory

java.lang.Object
  |
  +--org.apache.commons.collections.functors.ConstantFactory
All Implemented Interfaces:
Factory, Serializable

public class ConstantFactory
extends Object
implements Factory, 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: 1.2 $ $Date: 2004/01/14 21:43:09 $
Author:
Stephen Colebourne
See Also:
Serialized Form

Field Summary
static Factory NULL_INSTANCE
          Returns null each time
 
Constructor Summary
ConstantFactory(Object constantToReturn)
          Constructor that performs no validation.
 
Method Summary
 Object create()
          Always return constant
static Factory getInstance(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(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(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 Object create()
Always return constant
Specified by:
create in interface Factory
Following copied from interface: org.apache.commons.collections.Factory
Returns:
a new object
Throws:
FunctorException - (runtime) if the factory cannot create an object


Copyright © 2001-2004 Apache Software Foundation. All Rights Reserved.