TransformedPredicate.java
- /*
- * 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 java.util.Objects;
- import org.apache.commons.collections4.Predicate;
- import org.apache.commons.collections4.Transformer;
- /**
- * Predicate implementation that transforms the given object before invoking
- * another {@code Predicate}.
- *
- * @param <T> the type of the input to the predicate.
- * @since 3.1
- */
- public final class TransformedPredicate<T> extends AbstractPredicate<T> implements PredicateDecorator<T>, Serializable {
- /** Serial version UID */
- private static final long serialVersionUID = -5596090919668315834L;
- /**
- * Creates the predicate.
- *
- * @param <T> the type that the predicate queries
- * @param transformer the transformer to call
- * @param predicate the predicate to call with the result of the transform
- * @return the predicate
- * @throws NullPointerException if the transformer or the predicate is null
- */
- public static <T> Predicate<T> transformedPredicate(final Transformer<? super T, ? extends T> transformer,
- final Predicate<? super T> predicate) {
- return new TransformedPredicate<>(Objects.requireNonNull(transformer, "transformer"),
- Objects.requireNonNull(predicate, "predicate"));
- }
- /** The transformer to call */
- private final Transformer<? super T, ? extends T> iTransformer;
- /** The predicate to call */
- private final Predicate<? super T> iPredicate;
- /**
- * Constructor that performs no validation.
- * Use {@code transformedPredicate} if you want that.
- *
- * @param transformer the transformer to use
- * @param predicate the predicate to decorate
- */
- public TransformedPredicate(final Transformer<? super T, ? extends T> transformer,
- final Predicate<? super T> predicate) {
- iTransformer = transformer;
- iPredicate = predicate;
- }
- /**
- * Gets the predicate being decorated.
- *
- * @return the predicate as the only element in an array
- * @since 3.1
- */
- @Override
- @SuppressWarnings("unchecked")
- public Predicate<? super T>[] getPredicates() {
- return new Predicate[] {iPredicate};
- }
- /**
- * Gets the transformer in use.
- *
- * @return the transformer
- */
- public Transformer<? super T, ? extends T> getTransformer() {
- return iTransformer;
- }
- /**
- * 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
- */
- @Override
- public boolean test(final T object) {
- final T result = iTransformer.apply(object);
- return iPredicate.test(result);
- }
- }