Java tutorial
// GenericsNote: Converted. /* * Copyright 2001-2004 The Apache Software Foundation * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.collections15; /** * Defines a functor interface implemented by classes that perform a predicate * test on an object. * <p/> * A <code>Predicate</code> is the object equivalent of an <code>if</code> statement. * It uses the input object to return a true or false value, and is often used in * validation or filtering. * <p/> * Standard implementations of common predicates are provided by * {@link PredicateUtils}. These include true, false, instanceof, equals, and, * or, not, method invokation and null testing. * * @author James Strachan * @author Matt Hall, John Watkinson, Stephen Colebourne * @version $Revision: 1.1 $ $Date: 2005/10/11 17:05:19 $ * @since Commons Collections 1.0 */ public interface Predicate<T> { /** * Use the specified parameter to perform a test that returns true or false. * * @param object the object to evaluate, should not be changed * @return true or false * @throws ClassCastException (runtime) if the input is the wrong class * @throws IllegalArgumentException (runtime) if the input is invalid * @throws FunctorException (runtime) if the predicate encounters a problem */ public boolean evaluate(T object); }