1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.commons.io.function; 19 20 import java.io.IOException; 21 import java.io.UncheckedIOException; 22 import java.util.Objects; 23 import java.util.function.BiFunction; 24 import java.util.function.Function; 25 26 /** 27 * Like {@link BiFunction} but throws {@link IOException}. 28 * 29 * <p> 30 * This is a <a href="package-summary.html">functional interface</a> whose functional method is 31 * {@link #apply(Object, Object)}. 32 * </p> 33 * 34 * @param <T> the type of the first argument to the function 35 * @param <U> the type of the second argument to the function 36 * @param <R> the type of the result of the function 37 * 38 * @see Function 39 * @since 2.12.0 40 */ 41 @FunctionalInterface 42 public interface IOBiFunction<T, U, R> { 43 44 /** 45 * Returns the no-op singleton. 46 * 47 * @param <T> the type of the first argument to the function 48 * @param <U> the type of the second argument to the function 49 * @param <R> the type of the result of the function 50 * @return The no-op singleton. 51 */ noop()52 static <T, U, R> IOBiFunction<T, U, R> noop() { 53 return Constants.IO_BI_FUNCTION; 54 } 55 56 /** 57 * Creates a composed function that first applies this function to its input, and then applies the {@code after} 58 * function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the 59 * composed function. 60 * 61 * @param <V> the type of output of the {@code after} function, and of the composed function 62 * @param after the function to apply after this function is applied 63 * @return a composed function that first applies this function and then applies the {@code after} function 64 * @throws NullPointerException if after is null 65 */ andThen(final IOFunction<? super R, ? extends V> after)66 default <V> IOBiFunction<T, U, V> andThen(final IOFunction<? super R, ? extends V> after) { 67 Objects.requireNonNull(after); 68 return (final T t, final U u) -> after.apply(apply(t, u)); 69 } 70 71 /** 72 * Applies this function to the given arguments. 73 * 74 * @param t the first function argument 75 * @param u the second function argument 76 * @return the function result 77 * @throws IOException if an I/O error occurs. 78 */ apply(T t, U u)79 R apply(T t, U u) throws IOException; 80 81 /** 82 * Creates a {@link BiFunction} for this instance that throws {@link UncheckedIOException} instead of 83 * {@link IOException}. 84 * 85 * @return an UncheckedIOException BiFunction. 86 */ asBiFunction()87 default BiFunction<T, U, R> asBiFunction() { 88 return (t, u) -> Uncheck.apply(this, t, u); 89 } 90 } 91