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;
018    
019    import java.util.Collection;
020    import java.util.Comparator;
021    import java.util.SortedMap;
022    import java.util.TreeMap;
023    
024    /**
025     * A {@link Bag} that is backed by a {@link TreeMap}. 
026     * Order will be maintained among the unique representative
027     * members.
028     *
029     * @deprecated Moved to bag subpackage and rewritten internally. Due to be removed in v4.0.
030     * @since Commons Collections 2.0
031     * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
032     * 
033     * @author Chuck Burdick
034     */
035    public class TreeBag extends DefaultMapBag implements SortedBag {
036    
037        /**
038         * Constructs an empty <code>TreeBag</code>.
039         */
040        public TreeBag() {
041            super(new TreeMap());
042        }
043    
044        /**
045         * Constructs an empty {@link Bag} that maintains order on its unique
046         * representative members according to the given {@link Comparator}.
047         * 
048         * @param comparator  the comparator to use
049         */
050        public TreeBag(Comparator comparator) {
051            super(new TreeMap(comparator));
052        }
053    
054        /**
055         * Constructs a {@link Bag} containing all the members of the given
056         * collection.
057         * 
058         * @param coll  the collection to copy into the bag
059         */
060        public TreeBag(Collection coll) {
061            this();
062            addAll(coll);
063        }
064    
065        public Object first() {
066            return ((SortedMap) getMap()).firstKey();
067        }
068    
069        public Object last() {
070            return ((SortedMap) getMap()).lastKey();
071        }
072    
073        public Comparator comparator() {
074            return ((SortedMap) getMap()).comparator();
075        }
076        
077    }