org.apache.commons.collections.functors
Class NullPredicate

java.lang.Object
  extended by org.apache.commons.collections.functors.NullPredicate
All Implemented Interfaces:
java.io.Serializable, Predicate

public final class NullPredicate
extends java.lang.Object
implements Predicate, java.io.Serializable

Predicate implementation that returns true if the input is null.

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 Predicate INSTANCE
          Singleton predicate instance
 
Method Summary
 boolean evaluate(java.lang.Object object)
          Evaluates the predicate returning true if the input is null.
static Predicate getInstance()
          Factory returning the singleton instance.
 
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

getInstance

public static Predicate getInstance()
Factory returning the singleton instance.

Returns:
the singleton instance
Since:
Commons Collections 3.1

evaluate

public boolean evaluate(java.lang.Object object)
Evaluates the predicate returning true if the input is null.

Specified by:
evaluate in interface Predicate
Parameters:
object - the input object
Returns:
true if input is null


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