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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    *      https://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.concurrent;
19  
20  import java.util.Collection;
21  import java.util.concurrent.ExecutionException;
22  import java.util.concurrent.Future;
23  import java.util.concurrent.TimeUnit;
24  import java.util.concurrent.TimeoutException;
25  import java.util.stream.Collectors;
26  import java.util.stream.Stream;
27  
28  import org.apache.commons.lang3.exception.UncheckedInterruptedException;
29  
30  /**
31   * An {@link Future} that throws unchecked instead checked exceptions.
32   *
33   * @param <V> The result type returned by this Future's {@link #get()} and {@link #get(long, TimeUnit)} methods.
34   * @see Future
35   * @see Exception
36   * @since 3.13.0
37   */
38  public interface UncheckedFuture<V> extends Future<V> {
39  
40      /**
41       * Maps the given instances as unchecked.
42       *
43       * @param <T> The result type returned by the Futures' {@link #get()} and {@link #get(long, TimeUnit)} methods.
44       * @param futures The Futures to uncheck.
45       * @return a new stream.
46       */
47      static <T> Stream<UncheckedFuture<T>> map(final Collection<Future<T>> futures) {
48          return futures.stream().map(UncheckedFuture::on);
49      }
50  
51      /**
52       * Maps the given instances as unchecked.
53       *
54       * @param <T> The result type returned by the Futures' {@link #get()} and {@link #get(long, TimeUnit)} methods.
55       * @param futures The Futures to uncheck.
56       * @return a new collection.
57       */
58      static <T> Collection<UncheckedFuture<T>> on(final Collection<Future<T>> futures) {
59          return map(futures).collect(Collectors.toList());
60      }
61  
62      /**
63       * Creates a new instance on the given Future.
64       *
65       * @param <T> The result type returned by this Future's {@link #get()} and {@link #get(long, TimeUnit)} methods.
66       * @param future The Future to uncheck.
67       * @return a new instance.
68       */
69      static <T> UncheckedFuture<T> on(final Future<T> future) {
70          return new UncheckedFutureImpl<>(future);
71      }
72  
73      /**
74       * Gets per {@link Future#get()} but rethrows checked exceptions as unchecked.
75       * <p>
76       * The default mapping from checked to unchecked is:
77       * </p>
78       * <ul>
79       * <li>{@link InterruptedException} \u2192 {@link UncheckedInterruptedException}</li>
80       * <li>{@link ExecutionException} \u2192 {@link UncheckedExecutionException}</li>
81       * </ul>
82       */
83      @Override
84      V get();
85  
86      /**
87       * Gets per {@link Future#get(long, TimeUnit)} but rethrows checked exceptions as unchecked.
88       * <p>
89       * The default mapping from checked to unchecked is:
90       * </p>
91       * <ul>
92       * <li>{@link InterruptedException} \u2192 {@link UncheckedInterruptedException}</li>
93       * <li>{@link ExecutionException} \u2192 {@link UncheckedExecutionException}</li>
94       * <li>{@link TimeoutException} \u2192 {@link UncheckedTimeoutException}</li>
95       * </ul>
96       */
97      @Override
98      V get(long timeout, TimeUnit unit);
99  
100 }