001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.collections4.queue; 018 019import java.util.Queue; 020 021import org.apache.commons.collections4.collection.AbstractCollectionDecorator; 022 023/** 024 * Decorates another {@link Queue} to provide additional behaviour. 025 * <p> 026 * Methods are forwarded directly to the decorated queue. 027 * 028 * @param <E> the type of the elements in the queue 029 * @since 4.0 030 * @version $Id: AbstractQueueDecorator.html 972421 2015-11-14 20:00:04Z tn $ 031 */ 032public abstract class AbstractQueueDecorator<E> extends AbstractCollectionDecorator<E> 033 implements Queue<E> { 034 035 /** Serialization version */ 036 private static final long serialVersionUID = -2629815475789577029L; 037 038 /** 039 * Constructor only used in deserialization, do not use otherwise. 040 */ 041 protected AbstractQueueDecorator() { 042 super(); 043 } 044 045 /** 046 * Constructor that wraps (not copies). 047 * 048 * @param queue the queue to decorate, must not be null 049 * @throws IllegalArgumentException if list is null 050 */ 051 protected AbstractQueueDecorator(final Queue<E> queue) { 052 super(queue); 053 } 054 055 /** 056 * Gets the queue being decorated. 057 * 058 * @return the decorated queue 059 */ 060 @Override 061 protected Queue<E> decorated() { 062 return (Queue<E>) super.decorated(); 063 } 064 065 //----------------------------------------------------------------------- 066 067 public boolean offer(final E obj) { 068 return decorated().offer(obj); 069 } 070 071 public E poll() { 072 return decorated().poll(); 073 } 074 075 public E peek() { 076 return decorated().peek(); 077 } 078 079 public E element() { 080 return decorated().element(); 081 } 082 083 public E remove() { 084 return decorated().remove(); 085 } 086 087}