| /* |
| * 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.collections.functors; |
| |
| import java.io.Serializable; |
| |
| import org.apache.commons.collections.Predicate; |
| import org.apache.commons.collections.Transformer; |
| |
| /** |
| * Predicate implementation that transforms the given object before invoking |
| * another <code>Predicate</code>. |
| * |
| * @since Commons Collections 3.1 |
| * @version $Revision: 1.1 $ $Date: 2009/05/27 22:16:33 $ |
| * @author Alban Peignier |
| * @author Stephen Colebourne |
| */ |
| public final class TransformedPredicate implements Predicate, PredicateDecorator, Serializable { |
| |
| /** Serial version UID */ |
| private static final long serialVersionUID = -5596090919668315834L; |
| |
| /** The transformer to call */ |
| private final Transformer iTransformer; |
| /** The predicate to call */ |
| private final Predicate iPredicate; |
| |
| /** |
| * Factory to create the predicate. |
| * |
| * @param transformer the transformer to call |
| * @param predicate the predicate to call with the result of the transform |
| * @return the predicate |
| * @throws IllegalArgumentException if the transformer or the predicate is null |
| */ |
| public static Predicate getInstance(Transformer transformer, Predicate predicate) { |
| if (transformer == null) { |
| throw new IllegalArgumentException("The transformer to call must not be null"); |
| } |
| if (predicate == null) { |
| throw new IllegalArgumentException("The predicate to call must not be null"); |
| } |
| return new TransformedPredicate(transformer, predicate); |
| } |
| |
| /** |
| * Constructor that performs no validation. |
| * Use <code>getInstance</code> if you want that. |
| * |
| * @param transformer the transformer to use |
| * @param predicate the predicate to decorate |
| */ |
| public TransformedPredicate(Transformer transformer, Predicate predicate) { |
| iTransformer = transformer; |
| iPredicate = predicate; |
| } |
| |
| /** |
| * Evaluates the predicate returning the result of the decorated predicate |
| * once the input has been transformed |
| * |
| * @param object the input object which will be transformed |
| * @return true if decorated predicate returns true |
| */ |
| public boolean evaluate(Object object) { |
| Object result = iTransformer.transform(object); |
| return iPredicate.evaluate(result); |
| } |
| |
| /** |
| * Gets the predicate being decorated. |
| * |
| * @return the predicate as the only element in an array |
| * @since Commons Collections 3.1 |
| */ |
| public Predicate[] getPredicates() { |
| return new Predicate[] {iPredicate}; |
| } |
| |
| /** |
| * Gets the transformer in use. |
| * |
| * @return the transformer |
| */ |
| public Transformer getTransformer() { |
| return iTransformer; |
| } |
| |
| } |