    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      @Override
    036      protected abstract ListeningExecutorService delegate();
    037
    038      @Override
    039      public <T> ListenableFuture<T> submit(Callable<T> task) {
    040        return delegate().submit(task);
    041      }
    042
    043      @Override
    044      public ListenableFuture<?> submit(Runnable task) {
    045        return delegate().submit(task);
    046      }
    047
    048      @Override
    049      public <T> ListenableFuture<T> submit(Runnable task, T result) {
    050        return delegate().submit(task, result);
    051      }
    052    }