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.io.UncheckedIOException;
022import java.util.function.Supplier;
023
024/**
025 * Like {@link Supplier} but throws {@link IOException}.
026 * <p>
027 * Using an IOSupplier allows you to compose usage of checked and unchecked exceptions as you best see fit.
028 * </p>
029 *
030 * @param <T> the return type of the operations.
031 * @since 2.7
032 */
033@FunctionalInterface
034public interface IOSupplier<T> {
035
036    /**
037     * Creates a {@link Supplier} for this instance that throws {@link UncheckedIOException} instead of {@link IOException}.
038     *
039     * @return an UncheckedIOException Supplier.
040     * @since 2.12.0
041     */
042    default Supplier<T> asSupplier() {
043        return this::getUnchecked;
044    }
045
046    /**
047     * Gets a result.
048     *
049     * @return a result.
050     * @throws IOException if an I/O error occurs.
051     * @see #getUnchecked()
052     */
053    T get() throws IOException;
054
055    /**
056     * Gets a result.
057     *
058     * @return a result.
059     * @throws UncheckedIOException if an I/O error occurs.
060     * @see #get()
061     * @since 2.17.0
062     */
063    default T getUnchecked() throws UncheckedIOException {
064        return Uncheck.get(this);
065    }
066}