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 */ 017 package org.apache.commons.collections.bag; 018 019 import java.util.Comparator; 020 021 import org.apache.commons.collections.SortedBag; 022 023 /** 024 * Decorates another <code>SortedBag</code> to provide additional behaviour. 025 * <p> 026 * Methods are forwarded directly to the decorated bag. 027 * 028 * @since Commons Collections 3.0 029 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $ 030 * 031 * @author Stephen Colebourne 032 */ 033 public abstract class AbstractSortedBagDecorator 034 extends AbstractBagDecorator implements SortedBag { 035 036 /** 037 * Constructor only used in deserialization, do not use otherwise. 038 * @since Commons Collections 3.1 039 */ 040 protected AbstractSortedBagDecorator() { 041 super(); 042 } 043 044 /** 045 * Constructor that wraps (not copies). 046 * 047 * @param bag the bag to decorate, must not be null 048 * @throws IllegalArgumentException if list is null 049 */ 050 protected AbstractSortedBagDecorator(SortedBag bag) { 051 super(bag); 052 } 053 054 /** 055 * Gets the bag being decorated. 056 * 057 * @return the decorated bag 058 */ 059 protected SortedBag getSortedBag() { 060 return (SortedBag) getCollection(); 061 } 062 063 //----------------------------------------------------------------------- 064 public Object first() { 065 return getSortedBag().first(); 066 } 067 068 public Object last() { 069 return getSortedBag().last(); 070 } 071 072 public Comparator comparator() { 073 return getSortedBag().comparator(); 074 } 075 076 }