001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.lang3.concurrent;
019
020import java.util.Collection;
021import java.util.concurrent.ExecutionException;
022import java.util.concurrent.Future;
023import java.util.concurrent.TimeUnit;
024import java.util.concurrent.TimeoutException;
025import java.util.stream.Collectors;
026import java.util.stream.Stream;
027
028import org.apache.commons.lang3.exception.UncheckedInterruptedException;
029
030/**
031 * An {@link Future} that throws unchecked instead checked exceptions.
032 *
033 * @param <V> The result type returned by this Future's {@link #get()} and {@link #get(long, TimeUnit)} methods.
034 * @see Future
035 * @see Exception
036 * @since 3.13.0
037 */
038public interface UncheckedFuture<V> extends Future<V> {
039
040    /**
041     * Maps the given instances as unchecked.
042     *
043     * @param <T> The result type returned by the Futures' {@link #get()} and {@link #get(long, TimeUnit)} methods.
044     *
045     * @param futures The Futures to uncheck.
046     * @return a new stream.
047     */
048    static <T> Stream<UncheckedFuture<T>> map(final Collection<Future<T>> futures) {
049        return futures.stream().map(UncheckedFuture::on);
050    }
051
052    /**
053     * Maps the given instances as unchecked.
054     *
055     * @param <T> The result type returned by the Futures' {@link #get()} and {@link #get(long, TimeUnit)} methods.
056     *
057     * @param futures The Futures to uncheck.
058     * @return a new collection.
059     */
060    static <T> Collection<UncheckedFuture<T>> on(final Collection<Future<T>> futures) {
061        return map(futures).collect(Collectors.toList());
062    }
063
064    /**
065     * Creates a new instance on the given Future.
066     *
067     * @param <T> The result type returned by this Future's {@link #get()} and {@link #get(long, TimeUnit)} methods.
068     *
069     * @param future The Future to uncheck.
070     * @return a new instance.
071     */
072    static <T> UncheckedFuture<T> on(final Future<T> future) {
073        return new UncheckedFutureImpl<>(future);
074    }
075
076    /**
077     * Gets per {@link Future#get()} but rethrows checked exceptions as unchecked.
078     * <p>
079     * The default mapping from checked to unchecked is:
080     * </p>
081     * <ul>
082     * <li>{@link InterruptedException} \u2192 {@link UncheckedInterruptedException}</li>
083     * <li>{@link ExecutionException} \u2192 {@link UncheckedExecutionException}</li>
084     * </ul>
085     */
086    @Override
087    V get();
088
089    /**
090     * Gets per {@link Future#get(long, TimeUnit)} but rethrows checked exceptions as unchecked.
091     * <p>
092     * The default mapping from checked to unchecked is:
093     * </p>
094     * <ul>
095     * <li>{@link InterruptedException} \u2192 {@link UncheckedInterruptedException}</li>
096     * <li>{@link ExecutionException} \u2192 {@link UncheckedExecutionException}</li>
097     * <li>{@link TimeoutException} \u2192 {@link UncheckedTimeoutException}</li>
098     * </ul>
099     */
100    @Override
101    V get(long timeout, TimeUnit unit);
102
103}