001/*
002 * Copyright (C) 2011 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.google.common.util.concurrent;
018
019import com.google.common.collect.ForwardingObject;
020
021import java.util.Collection;
022import java.util.List;
023import java.util.concurrent.Callable;
024import java.util.concurrent.ExecutionException;
025import java.util.concurrent.ExecutorService;
026import java.util.concurrent.Future;
027import java.util.concurrent.TimeUnit;
028import java.util.concurrent.TimeoutException;
029
030/**
031 * An executor service which forwards all its method calls to another executor
032 * service. Subclasses should override one or more methods to modify the
033 * behavior of the backing executor service as desired per the <a
034 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
035 *
036 * @author Kurt Alfred Kluever
037 * @since 10.0
038 */
039public abstract class ForwardingExecutorService extends ForwardingObject
040    implements ExecutorService {
041  /** Constructor for use by subclasses. */
042  protected ForwardingExecutorService() {}
043  
044  @Override
045  protected abstract ExecutorService delegate();
046
047  @Override
048  public boolean awaitTermination(long timeout, TimeUnit unit)
049      throws InterruptedException {
050    return delegate().awaitTermination(timeout, unit);
051  }
052
053  @Override
054  public <T> List<Future<T>> invokeAll(
055      Collection<? extends Callable<T>> tasks) throws InterruptedException {
056    return delegate().invokeAll(tasks);
057  }
058
059  @Override
060  public <T> List<Future<T>> invokeAll(
061      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
062      throws InterruptedException {
063    return delegate().invokeAll(tasks, timeout, unit);
064  }
065
066  @Override
067  public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
068      throws InterruptedException, ExecutionException {
069    return delegate().invokeAny(tasks);
070  }
071
072  @Override
073  public <T> T invokeAny(
074      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
075      throws InterruptedException, ExecutionException, TimeoutException {
076    return delegate().invokeAny(tasks, timeout, unit);
077  }
078
079  @Override
080  public boolean isShutdown() {
081    return delegate().isShutdown();
082  }
083
084  @Override
085  public boolean isTerminated() {
086    return delegate().isTerminated();
087  }
088
089  @Override
090  public void shutdown() {
091    delegate().shutdown();
092  }
093
094  @Override
095  public List<Runnable> shutdownNow() {
096    return delegate().shutdownNow();
097  }
098
099  @Override
100  public void execute(Runnable command) {
101    delegate().execute(command);
102  }
103
104  public <T> Future<T> submit(Callable<T> task) {
105    return delegate().submit(task);
106  }
107
108  @Override
109  public Future<?> submit(Runnable task) {
110    return delegate().submit(task);
111  }
112
113  @Override
114  public <T> Future<T> submit(Runnable task, T result) {
115    return delegate().submit(task, result);
116  }
117}