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.map;
018
019 import java.util.Comparator;
020 import java.util.SortedMap;
021
022 /**
023 * Provides a base decorator that enables additional functionality to be added
024 * to a Map via decoration.
025 * <p>
026 * Methods are forwarded directly to the decorated map.
027 * <p>
028 * This implementation does not perform any special processing with the map views.
029 * Instead it simply returns the set/collection from the wrapped map. This may be
030 * undesirable, for example if you are trying to write a validating implementation
031 * it would provide a loophole around the validation.
032 * But, you might want that loophole, so this class is kept simple.
033 *
034 * @since Commons Collections 3.0
035 * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
036 *
037 * @author Stephen Colebourne
038 */
039 public abstract class AbstractSortedMapDecorator
040 extends AbstractMapDecorator implements SortedMap {
041
042 /**
043 * Constructor only used in deserialization, do not use otherwise.
044 * @since Commons Collections 3.1
045 */
046 protected AbstractSortedMapDecorator() {
047 super();
048 }
049
050 /**
051 * Constructor that wraps (not copies).
052 *
053 * @param map the map to decorate, must not be null
054 * @throws IllegalArgumentException if the collection is null
055 */
056 public AbstractSortedMapDecorator(SortedMap map) {
057 super(map);
058 }
059
060 /**
061 * Gets the map being decorated.
062 *
063 * @return the decorated map
064 */
065 protected SortedMap getSortedMap() {
066 return (SortedMap) map;
067 }
068
069 //-----------------------------------------------------------------------
070 public Comparator comparator() {
071 return getSortedMap().comparator();
072 }
073
074 public Object firstKey() {
075 return getSortedMap().firstKey();
076 }
077
078 public SortedMap headMap(Object toKey) {
079 return getSortedMap().headMap(toKey);
080 }
081
082 public Object lastKey() {
083 return getSortedMap().lastKey();
084 }
085
086 public SortedMap subMap(Object fromKey, Object toKey) {
087 return getSortedMap().subMap(fromKey, toKey);
088 }
089
090 public SortedMap tailMap(Object fromKey) {
091 return getSortedMap().tailMap(fromKey);
092 }
093
094 }