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.io.function;
019
020import java.io.IOException;
021import java.util.Objects;
022import java.util.function.Consumer;
023
024/**
025 * Like {@link Consumer} but throws {@link IOException}.
026 *
027 * @param <T> the type of the input to the operations.
028 * @since 2.7
029 */
030@FunctionalInterface
031public interface IOConsumer<T> {
032
033    /**
034     * Package private constant; consider private.
035     */
036    static final IOConsumer<?> NOOP_IO_CONSUMER = t -> {/* noop */};
037
038    /**
039     * Returns a constant NOOP consumer.
040     *
041     * @param <T> Type consumer type.
042     * @return a constant NOOP consumer.
043     * @since 2.9.0
044     */
045    @SuppressWarnings("unchecked")
046    public static <T> IOConsumer<T> noop() {
047        return (IOConsumer<T>) NOOP_IO_CONSUMER;
048    }
049
050    /**
051     * Performs this operation on the given argument.
052     *
053     * @param t the input argument
054     * @throws IOException if an I/O error occurs.
055     */
056    void accept(T t) throws IOException;
057
058    /**
059     * Returns a composed {@code IoConsumer} that performs, in sequence, this operation followed by the {@code after}
060     * operation. If performing either operation throws an exception, it is relayed to the caller of the composed
061     * operation. If performing this operation throws an exception, the {@code after} operation will not be performed.
062     *
063     * @param after the operation to perform after this operation
064     * @return a composed {@code Consumer} that performs in sequence this operation followed by the {@code after}
065     *         operation
066     * @throws NullPointerException if {@code after} is null
067     */
068    default IOConsumer<T> andThen(final IOConsumer<? super T> after) {
069        Objects.requireNonNull(after, "after");
070        return (final T t) -> {
071            accept(t);
072            after.accept(t);
073        };
074    }
075}