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.set;
018
019 import java.util.Comparator;
020 import java.util.SortedSet;
021
022 import org.apache.commons.collections.Transformer;
023
024 /**
025 * Decorates another <code>SortedSet</code> to transform objects that are added.
026 * <p>
027 * The add methods are affected by this class.
028 * Thus objects must be removed or searched for using their transformed form.
029 * For example, if the transformation converts Strings to Integers, you must
030 * use the Integer form to remove objects.
031 * <p>
032 * This class is Serializable from Commons Collections 3.1.
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 class TransformedSortedSet extends TransformedSet implements SortedSet {
040
041 /** Serialization version */
042 private static final long serialVersionUID = -1675486811351124386L;
043
044 /**
045 * Factory method to create a transforming sorted set.
046 * <p>
047 * If there are any elements already in the set being decorated, they
048 * are NOT transformed.
049 *
050 * @param set the set to decorate, must not be null
051 * @param transformer the transformer to use for conversion, must not be null
052 * @throws IllegalArgumentException if set or transformer is null
053 */
054 public static SortedSet decorate(SortedSet set, Transformer transformer) {
055 return new TransformedSortedSet(set, transformer);
056 }
057
058 //-----------------------------------------------------------------------
059 /**
060 * Constructor that wraps (not copies).
061 * <p>
062 * If there are any elements already in the set being decorated, they
063 * are NOT transformed.
064 *
065 * @param set the set to decorate, must not be null
066 * @param transformer the transformer to use for conversion, must not be null
067 * @throws IllegalArgumentException if set or transformer is null
068 */
069 protected TransformedSortedSet(SortedSet set, Transformer transformer) {
070 super(set, transformer);
071 }
072
073 /**
074 * Gets the decorated set.
075 *
076 * @return the decorated set
077 */
078 protected SortedSet getSortedSet() {
079 return (SortedSet) collection;
080 }
081
082 //-----------------------------------------------------------------------
083 public Object first() {
084 return getSortedSet().first();
085 }
086
087 public Object last() {
088 return getSortedSet().last();
089 }
090
091 public Comparator comparator() {
092 return getSortedSet().comparator();
093 }
094
095 //-----------------------------------------------------------------------
096 public SortedSet subSet(Object fromElement, Object toElement) {
097 SortedSet set = getSortedSet().subSet(fromElement, toElement);
098 return new TransformedSortedSet(set, transformer);
099 }
100
101 public SortedSet headSet(Object toElement) {
102 SortedSet set = getSortedSet().headSet(toElement);
103 return new TransformedSortedSet(set, transformer);
104 }
105
106 public SortedSet tailSet(Object fromElement) {
107 SortedSet set = getSortedSet().tailSet(fromElement);
108 return new TransformedSortedSet(set, transformer);
109 }
110
111 }