Class UniquePredicate

  • All Implemented Interfaces:
    java.io.Serializable, Predicate

    public final class UniquePredicate
    extends java.lang.Object
    implements Predicate, java.io.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) $
    See Also:
    Serialized Form
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.util.Set iSet
      The set of previously seen objects
      private static long serialVersionUID
      Serial version UID
    • Constructor Summary

      Constructors 
      Constructor Description
      UniquePredicate()
      Constructor that performs no validation.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean evaluate​(java.lang.Object object)
      Evaluates the predicate returning true if the input object hasn't been received yet.
      static Predicate getInstance()
      Factory to create the predicate.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • serialVersionUID

        private static final long serialVersionUID
        Serial version UID
        See Also:
        Constant Field Values
      • iSet

        private final java.util.Set iSet
        The set of previously seen objects
    • Constructor Detail

      • UniquePredicate

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

      • getInstance

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

        public boolean evaluate​(java.lang.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