| /* |
| * 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.io.Serializable; |
| |
| import org.apache.commons.collections4.Predicate; |
| import org.apache.commons.collections4.Transformer; |
| |
| /** |
| * Transformer implementation that calls a Predicate using the input object |
| * and then returns the result. |
| * |
| * @since 3.0 |
| * @version $Id$ |
| */ |
| public class PredicateTransformer<T> implements Transformer<T, Boolean>, Serializable { |
| |
| /** Serial version UID */ |
| private static final long serialVersionUID = 5278818408044349346L; |
| |
| /** The closure to wrap */ |
| private final Predicate<? super T> iPredicate; |
| |
| /** |
| * Factory method that performs validation. |
| * |
| * @param <T> the input type |
| * @param predicate the predicate to call, not null |
| * @return the <code>predicate</code> transformer |
| * @throws IllegalArgumentException if the predicate is null |
| */ |
| public static <T> Transformer<T, Boolean> predicateTransformer(final Predicate<? super T> predicate) { |
| if (predicate == null) { |
| throw new IllegalArgumentException("Predicate must not be null"); |
| } |
| return new PredicateTransformer<T>(predicate); |
| } |
| |
| /** |
| * Constructor that performs no validation. |
| * Use <code>predicateTransformer</code> if you want that. |
| * |
| * @param predicate the predicate to call, not null |
| */ |
| public PredicateTransformer(final Predicate<? super T> predicate) { |
| super(); |
| iPredicate = predicate; |
| } |
| |
| /** |
| * Transforms the input to result by calling a predicate. |
| * |
| * @param input the input object to transform |
| * @return the transformed result |
| */ |
| public Boolean transform(final T input) { |
| return Boolean.valueOf(iPredicate.evaluate(input)); |
| } |
| |
| /** |
| * Gets the predicate. |
| * |
| * @return the predicate |
| * @since 3.1 |
| */ |
| public Predicate<? super T> getPredicate() { |
| return iPredicate; |
| } |
| |
| } |