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 046@ElementTypesAreNonnullByDefault 047public abstract class ForwardingExecutorService extends ForwardingObject 048 implements ExecutorService { 049 /** Constructor for use by subclasses. */ 050 protected ForwardingExecutorService() {} 051 052 @Override 053 protected abstract ExecutorService delegate(); 054 055 @CheckReturnValue 056 @Override 057 public boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException { 058 return delegate().awaitTermination(timeout, unit); 059 } 060 061 @Override 062 public <T extends @Nullable Object> List<Future<T>> invokeAll( 063 Collection<? extends Callable<T>> tasks) throws InterruptedException { 064 return delegate().invokeAll(tasks); 065 } 066 067 @Override 068 public <T extends @Nullable Object> List<Future<T>> invokeAll( 069 Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) 070 throws InterruptedException { 071 return delegate().invokeAll(tasks, timeout, unit); 072 } 073 074 @Override 075 public <T extends @Nullable Object> T invokeAny(Collection<? extends Callable<T>> tasks) 076 throws InterruptedException, ExecutionException { 077 return delegate().invokeAny(tasks); 078 } 079 080 @Override 081 public <T extends @Nullable Object> T invokeAny( 082 Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) 083 throws InterruptedException, ExecutionException, TimeoutException { 084 return delegate().invokeAny(tasks, timeout, unit); 085 } 086 087 @Override 088 public boolean isShutdown() { 089 return delegate().isShutdown(); 090 } 091 092 @Override 093 public boolean isTerminated() { 094 return delegate().isTerminated(); 095 } 096 097 @Override 098 public void shutdown() { 099 delegate().shutdown(); 100 } 101 102 @Override 103 @CanIgnoreReturnValue 104 public List<Runnable> shutdownNow() { 105 return delegate().shutdownNow(); 106 } 107 108 @Override 109 public void execute(Runnable command) { 110 delegate().execute(command); 111 } 112 113 @Override 114 public <T extends @Nullable Object> Future<T> submit(Callable<T> task) { 115 return delegate().submit(task); 116 } 117 118 @Override 119 public Future<?> submit(Runnable task) { 120 return delegate().submit(task); 121 } 122 123 @Override 124 public <T extends @Nullable Object> Future<T> submit( 125 Runnable task, @ParametricNullness T result) { 126 return delegate().submit(task, result); 127 } 128}