    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}