11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2011 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.util.concurrent; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.Beta; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.base.Preconditions; 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.concurrent.TimeUnit; 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.concurrent.TimeoutException; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A future which forwards all its method calls to another future. Subclasses 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * should override one or more methods to modify the behavior of the backing 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * future as desired per the <a href= 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * "http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * <p>Most subclasses can simply extend {@link SimpleForwardingCheckedFuture}. 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @param <V> The result type returned by this Future's {@code get} method 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @param <X> The type of the Exception thrown by the Future's 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@code checkedGet} method 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Anthony Zana 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 9.0 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@Beta 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic abstract class ForwardingCheckedFuture<V, X extends Exception> 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert extends ForwardingListenableFuture<V> implements CheckedFuture<V, X> { 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public V checkedGet() throws X { 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().checkedGet(); 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public V checkedGet(long timeout, TimeUnit unit) throws TimeoutException, X { 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate().checkedGet(timeout, unit); 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected abstract CheckedFuture<V, X> delegate(); 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // TODO(cpovirk): Use Standard Javadoc form for SimpleForwarding* 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A simplified version of {@link ForwardingCheckedFuture} where subclasses 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * can pass in an already constructed {@link CheckedFuture} as the delegate. 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @since 9.0 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Beta 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public abstract static class SimpleForwardingCheckedFuture< 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert V, X extends Exception> extends ForwardingCheckedFuture<V, X> { 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private final CheckedFuture<V, X> delegate; 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected SimpleForwardingCheckedFuture(CheckedFuture<V, X> delegate) { 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert this.delegate = Preconditions.checkNotNull(delegate); 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert protected final CheckedFuture<V, X> delegate() { 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return delegate; 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 79