| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.collections4.functors; |
| |
| import java.util.Collection; |
| |
| import org.apache.commons.collections4.Predicate; |
| |
| /** |
| * Predicate implementation that returns true if only one of the |
| * predicates return true. |
| * If the array of predicates is empty, then this predicate returns false. |
| * <p> |
| * NOTE: In versions prior to 3.2 an array size of zero or one |
| * threw an exception. |
| * |
| * @since 3.0 |
| * @version $Id$ |
| */ |
| public final class OnePredicate<T> extends AbstractQuantifierPredicate<T> { |
| |
| /** Serial version UID */ |
| private static final long serialVersionUID = -8125389089924745785L; |
| |
| /** |
| * Factory to create the predicate. |
| * <p> |
| * If the array is size zero, the predicate always returns false. |
| * If the array is size one, then that predicate is returned. |
| * |
| * @param <T> the type that the predicate queries |
| * @param predicates the predicates to check, cloned, not null |
| * @return the <code>any</code> predicate |
| * @throws NullPointerException if the predicates array is null |
| * @throws NullPointerException if any predicate in the array is null |
| */ |
| @SuppressWarnings("unchecked") |
| public static <T> Predicate<T> onePredicate(final Predicate<? super T>... predicates) { |
| FunctorUtils.validate(predicates); |
| if (predicates.length == 0) { |
| return FalsePredicate.<T>falsePredicate(); |
| } |
| if (predicates.length == 1) { |
| return (Predicate<T>) predicates[0]; |
| } |
| return new OnePredicate<T>(FunctorUtils.copy(predicates)); |
| } |
| |
| /** |
| * Factory to create the predicate. |
| * |
| * @param <T> the type that the predicate queries |
| * @param predicates the predicates to check, cloned, not null |
| * @return the <code>one</code> predicate |
| * @throws NullPointerException if the predicates array is null |
| * @throws NullPointerException if any predicate in the array is null |
| */ |
| public static <T> Predicate<T> onePredicate(final Collection<? extends Predicate<? super T>> predicates) { |
| final Predicate<? super T>[] preds = FunctorUtils.validate(predicates); |
| return new OnePredicate<T>(preds); |
| } |
| |
| /** |
| * Constructor that performs no validation. |
| * Use <code>onePredicate</code> if you want that. |
| * |
| * @param predicates the predicates to check, not cloned, not null |
| */ |
| public OnePredicate(final Predicate<? super T>... predicates) { |
| super(predicates); |
| } |
| |
| /** |
| * Evaluates the predicate returning true if only one decorated predicate |
| * returns true. |
| * |
| * @param object the input object |
| * @return true if only one decorated predicate returns true |
| */ |
| public boolean evaluate(final T object) { |
| boolean match = false; |
| for (final Predicate<? super T> iPredicate : iPredicates) { |
| if (iPredicate.evaluate(object)) { |
| if (match) { |
| return false; |
| } |
| match = true; |
| } |
| } |
| return match; |
| } |
| |
| } |