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    
017    package com.google.common.util.concurrent;
018    
019    import java.util.concurrent.Callable;
020    
021    /**
022     * A listening executor service which forwards all its method calls to another
023     * listening executor service. Subclasses should override one or more methods to
024     * modify the behavior of the backing executor service as desired per the <a
025     * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
026     *
027     * @author Isaac Shum
028     * @since 10.0
029     */
030    public abstract class ForwardingListeningExecutorService
031        extends ForwardingExecutorService implements ListeningExecutorService {
032      /** Constructor for use by subclasses. */
033      protected ForwardingListeningExecutorService() {}
034    
035      
036      @Override
037      protected abstract ListeningExecutorService delegate();
038    
039      
040      @Override
041      public <T> ListenableFuture<T> submit(Callable<T> task) {
042        return delegate().submit(task);
043      }
044    
045      
046      @Override
047      public ListenableFuture<?> submit(Runnable task) {
048        return delegate().submit(task);
049      }
050    
051      
052      @Override
053      public <T> ListenableFuture<T> submit(Runnable task, T result) {
054        return delegate().submit(task, result);
055      }
056    }