1 /* 2 * Copyright (C) 2010 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.util.concurrent; 18 19 import com.google.common.collect.ForwardingQueue; 20 21 import java.util.Collection; 22 import java.util.concurrent.BlockingQueue; 23 import java.util.concurrent.TimeUnit; 24 25 /** 26 * A {@link BlockingQueue} which forwards all its method calls to another 27 * {@link BlockingQueue}. Subclasses should override one or more methods to 28 * modify the behavior of the backing collection as desired per the <a 29 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. 30 * 31 * @author Raimundo Mirisola 32 * 33 * @param <E> the type of elements held in this collection 34 * @since 4.0 35 */ 36 public abstract class ForwardingBlockingQueue<E> extends ForwardingQueue<E> 37 implements BlockingQueue<E> { 38 39 /** Constructor for use by subclasses. */ 40 protected ForwardingBlockingQueue() {} 41 42 @Override protected abstract BlockingQueue<E> delegate(); 43 44 @Override public int drainTo( 45 Collection<? super E> c, int maxElements) { 46 return delegate().drainTo(c, maxElements); 47 } 48 49 @Override public int drainTo(Collection<? super E> c) { 50 return delegate().drainTo(c); 51 } 52 53 @Override public boolean offer(E e, long timeout, TimeUnit unit) 54 throws InterruptedException { 55 return delegate().offer(e, timeout, unit); 56 } 57 58 @Override public E poll(long timeout, TimeUnit unit) 59 throws InterruptedException { 60 return delegate().poll(timeout, unit); 61 } 62 63 @Override public void put(E e) throws InterruptedException { 64 delegate().put(e); 65 } 66 67 @Override public int remainingCapacity() { 68 return delegate().remainingCapacity(); 69 } 70 71 @Override public E take() throws InterruptedException { 72 return delegate().take(); 73 } 74 } 75
