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.lang3.function;
19
20 import java.util.Objects;
21 import java.util.function.Consumer;
22 import java.util.function.Function;
23
24 /**
25 * A functional interface like {@link Consumer} that declares a {@link Throwable}.
26 *
27 * <p>
28 * This is a functional interface whose functional method is {@link #accept(Object)}.
29 * </p>
30 *
31 * @param <T> the type of the input to the operation
32 * @param <E> Thrown exception type.
33 * @since 3.11
34 */
35 @FunctionalInterface
36 public interface FailableConsumer<T, E extends Throwable> {
37
38 /** NOP singleton */
39 @SuppressWarnings("rawtypes")
40 FailableConsumer NOP = Function.identity()::apply;
41
42 /**
43 * Returns The NOP singleton.
44 *
45 * @param <T> Consumed type 1.
46 * @param <E> The kind of thrown exception or error.
47 * @return The NOP singleton.
48 */
49 @SuppressWarnings("unchecked")
50 static <T, E extends Throwable> FailableConsumer<T, E> nop() {
51 return NOP;
52 }
53
54 /**
55 * Accepts the given arguments.
56 *
57 * @param object the parameter for the consumable to accept
58 * @throws E Thrown when the consumer fails.
59 */
60 void accept(T object) throws E;
61
62 /**
63 * Returns a composed {@link Consumer} like {@link Consumer#andThen(Consumer)}.
64 *
65 * @param after the operation to perform after this operation
66 * @return a composed {@link Consumer} like {@link Consumer#andThen(Consumer)}.
67 * @throws NullPointerException when {@code after} is null
68 */
69 default FailableConsumer<T, E> andThen(final FailableConsumer<? super T, E> after) {
70 Objects.requireNonNull(after);
71 return (final T t) -> {
72 accept(t);
73 after.accept(t);
74 };
75 }
76 }