Package org.apache.commons.collections

Interface Predicate

All Known Subinterfaces:
PredicateDecorator
All Known Implementing Classes:
AllPredicate, AndPredicate, AnyPredicate, EqualPredicate, ExceptionPredicate, FalsePredicate, IdentityPredicate, InstanceofPredicate, NonePredicate, NotNullPredicate, NotPredicate, NullIsExceptionPredicate, NullIsFalsePredicate, NullIsTruePredicate, NullPredicate, OnePredicate, OrPredicate, TransformedPredicate, TransformerPredicate, TruePredicate, UniquePredicate
public interface Predicate
Defines a functor interface implemented by classes that perform a predicate test on an object.

A Predicate is the object equivalent of an if statement. It uses the input object to return a true or false value, and is often used in validation or filtering.

Standard implementations of common predicates are provided by PredicateUtils. These include true, false, instanceof, equals, and, or, not, method invokation and null testing.

Since:
Commons Collections 1.0
Version:
$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
Author:
James Strachan, Stephen Colebourne

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    evaluate(Object object)
    Use the specified parameter to perform a test that returns true or false.

  • Method Details

    • evaluate

      boolean evaluate(Object object)
      Use the specified parameter to perform a test that returns true or false.
      Parameters:
      object - the object to evaluate, should not be changed
      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