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 }