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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.BiConsumer;
22  
23  /**
24   * A functional interface like {@link BiConsumer} that declares a {@link Throwable}.
25   *
26   * @param <T> Consumed type 1.
27   * @param <U> Consumed type 2.
28   * @param <E> The kind of thrown exception or error.
29   * @since 3.11
30   */
31  @FunctionalInterface
32  public interface FailableBiConsumer<T, U, E extends Throwable> {
33  
34      /** NOP singleton */
35      @SuppressWarnings("rawtypes")
36      FailableBiConsumer NOP = (t, u) -> { /* NOP */ };
37  
38      /**
39       * Returns The NOP singleton.
40       *
41       * @param <T> Consumed type 1.
42       * @param <U> Consumed type 2.
43       * @param <E> The kind of thrown exception or error.
44       * @return The NOP singleton.
45       */
46      @SuppressWarnings("unchecked")
47      static <T, U, E extends Throwable> FailableBiConsumer<T, U, E> nop() {
48          return NOP;
49      }
50  
51      /**
52       * Accepts the given arguments.
53       *
54       * @param t the first parameter for the consumable to accept
55       * @param u the second parameter for the consumable to accept
56       * @throws E Thrown when the consumer fails.
57       */
58      void accept(T t, U u) throws E;
59  
60      /**
61       * Returns a composed {@link FailableBiConsumer} like {@link BiConsumer#andThen(BiConsumer)}.
62       *
63       * @param after the operation to perform after this one.
64       * @return a composed {@link FailableBiConsumer} like {@link BiConsumer#andThen(BiConsumer)}.
65       * @throws NullPointerException when {@code after} is null.
66       */
67      default FailableBiConsumer<T, U, E> andThen(final FailableBiConsumer<? super T, ? super U, E> after) {
68          Objects.requireNonNull(after);
69          return (t, u) -> {
70              accept(t, u);
71              after.accept(t, u);
72          };
73      }
74  }