| /* |
| * Copyright (C) 2008 The Guava Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except |
| * in compliance with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software distributed under the License |
| * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express |
| * or implied. See the License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| |
| package com.google.common.util.concurrent; |
| |
| import com.google.common.annotations.Beta; |
| import com.google.common.annotations.GwtIncompatible; |
| import com.google.errorprone.annotations.CanIgnoreReturnValue; |
| import java.util.concurrent.CancellationException; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.TimeoutException; |
| |
| /** |
| * A delegating wrapper around a {@link ListenableFuture} that adds support for the {@link |
| * #checkedGet()} and {@link #checkedGet(long, TimeUnit)} methods. |
| * |
| * @author Sven Mawson |
| * @since 1.0 |
| * @deprecated {@link CheckedFuture} cannot properly support the chained operations that are the |
| * primary goal of {@link ListenableFuture}. {@code CheckedFuture} also encourages users to |
| * rethrow exceptions from one thread in another thread, producing misleading stack traces. |
| * Additionally, it has a surprising policy about which exceptions to map and which to leave |
| * untouched. Guava users who want a {@code CheckedFuture} can fork the classes for their own |
| * use, possibly specializing them to the particular exception type they use. We recommend that |
| * most people use {@code ListenableFuture} and perform any exception wrapping themselves. This |
| * class is scheduled for removal from Guava in January 2019. |
| */ |
| // TODO(b/72241575): Remove by 2019-01 |
| @Beta |
| @Deprecated |
| @GwtIncompatible |
| public abstract class AbstractCheckedFuture<V, X extends Exception> |
| extends ForwardingListenableFuture.SimpleForwardingListenableFuture<V> |
| implements CheckedFuture<V, X> { |
| /** Constructs an {@code AbstractCheckedFuture} that wraps a delegate. */ |
| protected AbstractCheckedFuture(ListenableFuture<V> delegate) { |
| super(delegate); |
| } |
| |
| /** |
| * Translates from an {@link InterruptedException}, {@link CancellationException} or {@link |
| * ExecutionException} thrown by {@code get} to an exception of type {@code X} to be thrown by |
| * {@code checkedGet}. Subclasses must implement this method. |
| * |
| * <p>If {@code e} is an {@code InterruptedException}, the calling {@code checkedGet} method has |
| * already restored the interrupt after catching the exception. If an implementation of {@link |
| * #mapException(Exception)} wishes to swallow the interrupt, it can do so by calling {@link |
| * Thread#interrupted()}. |
| * |
| * <p>Subclasses may choose to throw, rather than return, a subclass of {@code RuntimeException} |
| * to allow creating a CheckedFuture that throws both checked and unchecked exceptions. |
| */ |
| // We might like @ForOverride here, but some subclasses invoke this from their get() methods. |
| protected abstract X mapException(Exception e); |
| |
| /** |
| * {@inheritDoc} |
| * |
| * <p>This implementation calls {@link #get()} and maps that method's standard exceptions to |
| * instances of type {@code X} using {@link #mapException}. |
| * |
| * <p>In addition, if {@code get} throws an {@link InterruptedException}, this implementation will |
| * set the current thread's interrupt status before calling {@code mapException}. |
| * |
| * @throws X if {@link #get()} throws an {@link InterruptedException}, {@link |
| * CancellationException}, or {@link ExecutionException} |
| */ |
| @CanIgnoreReturnValue |
| @Override |
| public V checkedGet() throws X { |
| try { |
| return get(); |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| throw mapException(e); |
| } catch (CancellationException | ExecutionException e) { |
| throw mapException(e); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * <p>This implementation calls {@link #get(long, TimeUnit)} and maps that method's standard |
| * exceptions (excluding {@link TimeoutException}, which is propagated) to instances of type |
| * {@code X} using {@link #mapException}. |
| * |
| * <p>In addition, if {@code get} throws an {@link InterruptedException}, this implementation will |
| * set the current thread's interrupt status before calling {@code mapException}. |
| * |
| * @throws X if {@link #get()} throws an {@link InterruptedException}, {@link |
| * CancellationException}, or {@link ExecutionException} |
| */ |
| @CanIgnoreReturnValue |
| @Override |
| public V checkedGet(long timeout, TimeUnit unit) throws TimeoutException, X { |
| try { |
| return get(timeout, unit); |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| throw mapException(e); |
| } catch (CancellationException | ExecutionException e) { |
| throw mapException(e); |
| } |
| } |
| } |