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.collect.ForwardingObject; 019import com.google.errorprone.annotations.CanIgnoreReturnValue; 020import com.google.errorprone.annotations.CheckReturnValue; 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; 029import org.checkerframework.checker.nullness.qual.Nullable; 030 031/** 032 * An executor service which forwards all its method calls to another executor service. Subclasses 033 * should override one or more methods to modify the behavior of the backing executor service as 034 * desired per the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. 035 * 036 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code 037 * default} methods. Instead, it inherits their default implementations. When those implementations 038 * invoke methods, they invoke methods on the {@code ForwardingExecutorService}. 039 * 040 * @author Kurt Alfred Kluever 041 * @since 10.0 042 */ 043@GwtIncompatible 044@ElementTypesAreNonnullByDefault 045public abstract class ForwardingExecutorService extends ForwardingObject 046 implements ExecutorService { 047 /** Constructor for use by subclasses. */ 048 protected ForwardingExecutorService() {} 049 050 @Override 051 protected abstract ExecutorService delegate(); 052 053 @CheckReturnValue 054 @Override 055 public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException { 056 return delegate().awaitTermination(timeout, unit); 057 } 058 059 @Override 060 public <T extends @Nullable Object> List<Future<T>> invokeAll( 061 Collection<? extends Callable<T>> tasks) throws InterruptedException { 062 return delegate().invokeAll(tasks); 063 } 064 065 @Override 066 public <T extends @Nullable Object> List<Future<T>> invokeAll( 067 Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) 068 throws InterruptedException { 069 return delegate().invokeAll(tasks, timeout, unit); 070 } 071 072 @Override 073 public <T extends @Nullable Object> T invokeAny(Collection<? extends Callable<T>> tasks) 074 throws InterruptedException, ExecutionException { 075 return delegate().invokeAny(tasks); 076 } 077 078 @Override 079 public <T extends @Nullable Object> T invokeAny( 080 Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) 081 throws InterruptedException, ExecutionException, TimeoutException { 082 return delegate().invokeAny(tasks, timeout, unit); 083 } 084 085 @Override 086 public boolean isShutdown() { 087 return delegate().isShutdown(); 088 } 089 090 @Override 091 public boolean isTerminated() { 092 return delegate().isTerminated(); 093 } 094 095 @Override 096 public void shutdown() { 097 delegate().shutdown(); 098 } 099 100 @Override 101 @CanIgnoreReturnValue 102 public List<Runnable> shutdownNow() { 103 return delegate().shutdownNow(); 104 } 105 106 @Override 107 public void execute(Runnable command) { 108 delegate().execute(command); 109 } 110 111 @Override 112 public <T extends @Nullable Object> Future<T> submit(Callable<T> task) { 113 return delegate().submit(task); 114 } 115 116 @Override 117 public Future<?> submit(Runnable task) { 118 return delegate().submit(task); 119 } 120 121 @Override 122 public <T extends @Nullable Object> Future<T> submit( 123 Runnable task, @ParametricNullness T result) { 124 return delegate().submit(task, result); 125 } 126}