org.apache.commons.collections.functors
Class ConstantTransformer
java.lang.Object
|
+--org.apache.commons.collections.functors.ConstantTransformer
- All Implemented Interfaces:
- Serializable, Transformer
- public class ConstantTransformer
- extends Object
- implements Transformer, Serializable
Transformer 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
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
NULL_INSTANCE
public static final Transformer NULL_INSTANCE
- Returns null each time
ConstantTransformer
public ConstantTransformer(Object constantToReturn)
- Constructor that performs no validation.
Use
getInstance
if you want that.
- Parameters:
constantToReturn
- the constant to return each time
getInstance
public static Transformer getInstance(Object constantToReturn)
- Transformer method that performs validation.
- Parameters:
constantToReturn
- the constant object to return each time in the factory- Returns:
- the
constant
factory.
transform
public Object transform(Object input)
- Always return constant.
- Specified by:
transform
in interface Transformer
- Following copied from interface:
org.apache.commons.collections.Transformer
- Parameters:
input
- the object to be transformed- Returns:
- a transformed object
- Throws:
ClassCastException
- (runtime) if the input is the wrong classIllegalArgumentException
- (runtime) if the input is invalidFunctorException
- (runtime) if the transform cannot be completed
Copyright © 2001-2004 Apache Software Foundation. All Rights Reserved.