Package org.apache.commons.collections.functors

Class UniquePredicate

java.lang.Object
org.apache.commons.collections.functors.UniquePredicate
All Implemented Interfaces:
Serializable, Predicate
public final class UniquePredicate extends Object implements Predicate, Serializable
Predicate implementation that returns true the first time an object is passed into the predicate.
Since:
Commons Collections 3.0
Version:
$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
Author:
Stephen Colebourne
See Also:

  • Constructor Details

    • UniquePredicate

      public UniquePredicate()
      Constructor that performs no validation. Use getInstance if you want that.

  • Method Details

    • getInstance

      public static Predicate getInstance()
      Factory to create the predicate.
      Returns:
      the predicate
      Throws:
      IllegalArgumentException - if the predicate is null

    • evaluate

      public boolean evaluate(Object object)
      Evaluates the predicate returning true if the input object hasn't been received yet.
      Specified by:
      evaluate in interface Predicate
      Parameters:
      object - the input object
      Returns:
      true if this is the first time the object is seen