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.base.Preconditions;
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
*/
@Beta
public abstract class ForwardingCheckedFuture
extends ForwardingListenableFuture implements CheckedFuture {
@Override
public V checkedGet() throws X {
return delegate().checkedGet();
}
@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
*/
@Beta
public abstract static class SimpleForwardingCheckedFuture<
V, X extends Exception> extends ForwardingCheckedFuture {
private final CheckedFuture delegate;
protected SimpleForwardingCheckedFuture(CheckedFuture delegate) {
this.delegate = Preconditions.checkNotNull(delegate);
}
@Override
protected final CheckedFuture delegate() {
return delegate;
}
}
}