    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.lang3.function;
    019
    020import java.util.Objects;
    021import java.util.function.Consumer;
    022
    023/**
    024 * A functional interface like {@link Consumer} that declares a {@code Throwable}.
    025 *
    026 * @param <T> Consumed type 1.
    027 * @param <E> Thrown exception.
    028 * @since 3.11
    029 */
    030@FunctionalInterface
    031public interface FailableConsumer<T, E extends Throwable> {
    032
    033    /** NOP singleton */
    034    @SuppressWarnings("rawtypes")
    035    FailableConsumer NOP = t -> {/* NOP */};
    036
    037    /**
    038     * Returns The NOP singleton.
    039     *
    040     * @param <T> Consumed type 1.
    041     * @param <E> Thrown exception.
    042     * @return The NOP singleton.
    043     */
    044    static <T, E extends Throwable> FailableConsumer<T, E> nop() {
    045        return NOP;
    046    }
    047
    048    /**
    049     * Accepts the consumer.
    050     *
    051     * @param object the parameter for the consumable to accept
    052     * @throws E Thrown when the consumer fails.
    053     */
    054    void accept(T object) throws E;
    055
    056    /**
    057     * Returns a composed {@code Consumer} like {@link Consumer#andThen(Consumer)}.
    058     *
    059     * @param after the operation to perform after this operation
    060     * @return a composed {@code Consumer} like {@link Consumer#andThen(Consumer)}.
    061     * @throws NullPointerException when {@code after} is null
    062     */
    063    default FailableConsumer<T, E> andThen(final FailableConsumer<? super T, E> after) {
    064        Objects.requireNonNull(after);
    065        return (final T t) -> {
    066            accept(t);
    067            after.accept(t);
    068        };
    069    }
    070}