001/*
002 * Copyright (C) 2011 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005 * in compliance with the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the License
010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
011 * or implied. See the License for the specific language governing permissions and limitations under
012 * the License.
013 */
014
015package com.google.common.util.concurrent;
016
017import com.google.common.annotations.GwtIncompatible;
018import com.google.common.annotations.J2ktIncompatible;
019import com.google.common.collect.ForwardingObject;
020import com.google.errorprone.annotations.CanIgnoreReturnValue;
021import com.google.errorprone.annotations.CheckReturnValue;
022import java.util.Collection;
023import java.util.List;
024import java.util.concurrent.Callable;
025import java.util.concurrent.ExecutionException;
026import java.util.concurrent.ExecutorService;
027import java.util.concurrent.Future;
028import java.util.concurrent.TimeUnit;
029import java.util.concurrent.TimeoutException;
030import org.checkerframework.checker.nullness.qual.Nullable;
031
032/**
033 * An executor service which forwards all its method calls to another executor service. Subclasses
034 * should override one or more methods to modify the behavior of the backing executor service as
035 * desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
036 *
037 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
038 * default} methods. Instead, it inherits their default implementations. When those implementations
039 * invoke methods, they invoke methods on the {@code ForwardingExecutorService}.
040 *
041 * @author Kurt Alfred Kluever
042 * @since 10.0
043 */
044@J2ktIncompatible
045@GwtIncompatible
046public abstract class ForwardingExecutorService extends ForwardingObject
047    implements ExecutorService {
048  /** Constructor for use by subclasses. */
049  protected ForwardingExecutorService() {}
050
051  @Override
052  protected abstract ExecutorService delegate();
053
054  @CheckReturnValue
055  @Override
056  public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
057    return delegate().awaitTermination(timeout, unit);
058  }
059
060  @Override
061  public <T extends @Nullable Object> List<Future<T>> invokeAll(
062      Collection<? extends Callable<T>> tasks) throws InterruptedException {
063    return delegate().invokeAll(tasks);
064  }
065
066  @Override
067  public <T extends @Nullable Object> List<Future<T>> invokeAll(
068      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
069      throws InterruptedException {
070    return delegate().invokeAll(tasks, timeout, unit);
071  }
072
073  @Override
074  public <T extends @Nullable Object> T invokeAny(Collection<? extends Callable<T>> tasks)
075      throws InterruptedException, ExecutionException {
076    return delegate().invokeAny(tasks);
077  }
078
079  @Override
080  public <T extends @Nullable Object> T invokeAny(
081      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
082      throws InterruptedException, ExecutionException, TimeoutException {
083    return delegate().invokeAny(tasks, timeout, unit);
084  }
085
086  @Override
087  public boolean isShutdown() {
088    return delegate().isShutdown();
089  }
090
091  @Override
092  public boolean isTerminated() {
093    return delegate().isTerminated();
094  }
095
096  @Override
097  public void shutdown() {
098    delegate().shutdown();
099  }
100
101  @Override
102  @CanIgnoreReturnValue
103  public List<Runnable> shutdownNow() {
104    return delegate().shutdownNow();
105  }
106
107  @Override
108  public void execute(Runnable command) {
109    delegate().execute(command);
110  }
111
112  @Override
113  public <T extends @Nullable Object> Future<T> submit(Callable<T> task) {
114    return delegate().submit(task);
115  }
116
117  @Override
118  public Future<?> submit(Runnable task) {
119    return delegate().submit(task);
120  }
121
122  @Override
123  public <T extends @Nullable Object> Future<T> submit(
124      Runnable task, @ParametricNullness T result) {
125    return delegate().submit(task, result);
126  }
127}