com.google.common.util.concurrent.ForwardingCheckedFuture Maven / Gradle / Ivy
/*
* Copyright (C) 2011 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.common.base.Preconditions;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
/**
* A future which forwards all its method calls to another future. Subclasses should override one or
* more methods to modify the behavior of the backing future as desired per the decorator pattern.
*
* Most subclasses can simply extend {@link SimpleForwardingCheckedFuture}.
*
* @param The result type returned by this Future's {@code get} method
* @param The type of the Exception thrown by the Future's {@code checkedGet} method
* @author Anthony Zana
* @since 9.0
* @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 February 2018.
*/
@Beta
@Deprecated
@GwtIncompatible
public abstract class ForwardingCheckedFuture
extends ForwardingListenableFuture implements CheckedFuture {
@CanIgnoreReturnValue
@Override
public V checkedGet() throws X {
return delegate().checkedGet();
}
@CanIgnoreReturnValue
@Override
public V checkedGet(long timeout, TimeUnit unit) throws TimeoutException, X {
return delegate().checkedGet(timeout, unit);
}
@Override
protected abstract CheckedFuture delegate();
// TODO(cpovirk): Use Standard Javadoc form for SimpleForwarding*
/**
* A simplified version of {@link ForwardingCheckedFuture} where subclasses can pass in an already
* constructed {@link CheckedFuture} as the delegate.
*
* @since 9.0
* @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 February 2018.
*/
@Beta
@Deprecated
public abstract static class SimpleForwardingCheckedFuture
extends ForwardingCheckedFuture {
private final CheckedFuture delegate;
protected SimpleForwardingCheckedFuture(CheckedFuture delegate) {
this.delegate = Preconditions.checkNotNull(delegate);
}
@Override
protected final CheckedFuture delegate() {
return delegate;
}
}
}