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 * @see Function
38 * @since 2.12.0
39 */
40 @FunctionalInterface
41 public interface IOBiFunction<T, U, R> {
42
43 /**
44 * Creates a composed function that first applies this function to its input, and then applies the {@code after}
45 * function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the
46 * composed function.
47 *
48 * @param <V> the type of output of the {@code after} function, and of the composed function
49 * @param after the function to apply after this function is applied
50 * @return a composed function that first applies this function and then applies the {@code after} function
51 * @throws NullPointerException if after is null
52 */
53 default <V> IOBiFunction<T, U, V> andThen(final IOFunction<? super R, ? extends V> after) {
54 Objects.requireNonNull(after);
55 return (final T t, final U u) -> after.apply(apply(t, u));
56 }
57
58 /**
59 * Applies this function to the given arguments.
60 *
61 * @param t the first function argument
62 * @param u the second function argument
63 * @return the function result
64 * @throws IOException if an I/O error occurs.
65 */
66 R apply(T t, U u) throws IOException;
67
68 /**
69 * Creates a {@link BiFunction} for this instance that throws {@link UncheckedIOException} instead of
70 * {@link IOException}.
71 *
72 * @return an UncheckedIOException BiFunction.
73 */
74 default BiFunction<T, U, R> asBiFunction() {
75 return (t, u) -> Uncheck.apply(this, t, u);
76 }
77 }