org.apache.commons.collections.functors
Class NullPredicate

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

public final class NullPredicate
extends Object
implements Predicate, Serializable

Predicate implementation that returns true if the input is null.

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 Predicate INSTANCE
          Singleton predicate instance
 
Method Summary
 boolean evaluate(Object object)
          Return true if the object equals null.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

INSTANCE

public static final Predicate INSTANCE
Singleton predicate instance
Method Detail

evaluate

public boolean evaluate(Object object)
Return true if the object equals null.
Specified by:
evaluate in interface Predicate
Following copied from interface: org.apache.commons.collections.Predicate
Parameters:
object - the object to evaluate
Returns:
true or false
Throws:
ClassCastException - (runtime) if the input is the wrong class
IllegalArgumentException - (runtime) if the input is invalid
FunctorException - (runtime) if the predicate encounters a problem


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