1 /*
2 * Copyright (C) 2011 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14
15 package com.google.common.util.concurrent;
16
17 import com.google.common.annotations.GwtIncompatible;
18 import com.google.errorprone.annotations.CanIgnoreReturnValue;
19 import java.util.concurrent.Callable;
20 import org.checkerframework.checker.nullness.qual.Nullable;
21
22 /**
23 * A listening executor service which forwards all its method calls to another listening executor
24 * service. Subclasses should override one or more methods to modify the behavior of the backing
25 * executor service as desired per the <a
26 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
27 *
28 * @author Isaac Shum
29 * @since 10.0
30 */
31 @CanIgnoreReturnValue // TODO(cpovirk): Consider being more strict.
32 @GwtIncompatible
33 @ElementTypesAreNonnullByDefault
34 public abstract class ForwardingListeningExecutorService extends ForwardingExecutorService
35 implements ListeningExecutorService {
36 /** Constructor for use by subclasses. */
37 protected ForwardingListeningExecutorService() {}
38
39 @Override
40 protected abstract ListeningExecutorService delegate();
41
42 @Override
43 public <T extends @Nullable Object> ListenableFuture<T> submit(Callable<T> task) {
44 return delegate().submit(task);
45 }
46
47 @Override
48 public ListenableFuture<?> submit(Runnable task) {
49 return delegate().submit(task);
50 }
51
52 @Override
53 public <T extends @Nullable Object> ListenableFuture<T> submit(
54 Runnable task, @ParametricNullness T result) {
55 return delegate().submit(task, result);
56 }
57 }