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;
022import java.util.function.Function;
023
024/**
025 * A functional interface like {@link Consumer} that declares a {@link Throwable}.
026 *
027 * <p>
028 * This is a functional interface whose functional method is {@link #accept(Object)}.
029 * </p>
030 *
031 * @param <T> the type of the input to the operation
032 * @param <E> Thrown exception type.
033 * @since 3.11
034 */
035@FunctionalInterface
036public interface FailableConsumer<T, E extends Throwable> {
037
038    /** NOP singleton */
039    @SuppressWarnings("rawtypes")
040    FailableConsumer NOP = Function.identity()::apply;
041
042    /**
043     * Returns The NOP singleton.
044     *
045     * @param <T> Consumed type 1.
046     * @param <E> The kind of thrown exception or error.
047     * @return The NOP singleton.
048     */
049    @SuppressWarnings("unchecked")
050    static <T, E extends Throwable> FailableConsumer<T, E> nop() {
051        return NOP;
052    }
053
054    /**
055     * Accepts the given arguments.
056     *
057     * @param object the parameter for the consumable to accept
058     * @throws E Thrown when the consumer fails.
059     */
060    void accept(T object) throws E;
061
062    /**
063     * Returns a composed {@link Consumer} like {@link Consumer#andThen(Consumer)}.
064     *
065     * @param after the operation to perform after this operation
066     * @return a composed {@link Consumer} like {@link Consumer#andThen(Consumer)}.
067     * @throws NullPointerException when {@code after} is null
068     */
069    default FailableConsumer<T, E> andThen(final FailableConsumer<? super T, E> after) {
070        Objects.requireNonNull(after);
071        return (final T t) -> {
072            accept(t);
073            after.accept(t);
074        };
075    }
076}