1/*
2 * Copyright (C) 2009 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.common.util.concurrent;
18
19import com.google.common.collect.ForwardingObject;
20
21import java.util.concurrent.ExecutionException;
22import java.util.concurrent.Future;
23import java.util.concurrent.TimeUnit;
24import java.util.concurrent.TimeoutException;
25
26/**
27 * A {@link Future} which forwards all its method calls to another future.
28 * Subclasses should override one or more methods to modify the behavior of
29 * the backing collection as desired per the <a
30 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
31 *
32 * @see ForwardingObject
33 * @author Sven Mawson
34 * @since 2009.09.15 <b>tentative</b>
35 */
36public abstract class ForwardingFuture<V> extends ForwardingObject
37    implements Future<V> {
38
39  @Override protected abstract Future<V> delegate();
40
41  /*@Override*/
42  public boolean cancel(boolean mayInterruptIfRunning) {
43    return delegate().cancel(mayInterruptIfRunning);
44  }
45
46  /*@Override*/
47  public boolean isCancelled() {
48    return delegate().isCancelled();
49  }
50
51  /*@Override*/
52  public boolean isDone() {
53    return delegate().isDone();
54  }
55
56  /*@Override*/
57  public V get() throws InterruptedException, ExecutionException {
58    return delegate().get();
59  }
60
61  /*@Override*/
62  public V get(long timeout, TimeUnit unit)
63      throws InterruptedException, ExecutionException, TimeoutException {
64    return delegate().get(timeout, unit);
65  }
66}
67