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 */ 017package org.apache.commons.collections4.set; 018 019import java.util.Comparator; 020import java.util.SortedSet; 021 022import org.apache.commons.collections4.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 * @param <E> the type of the elements in this set 035 * @since 3.0 036 */ 037public class TransformedSortedSet<E> extends TransformedSet<E> implements SortedSet<E> { 038 039 /** Serialization version */ 040 private static final long serialVersionUID = -1675486811351124386L; 041 042 /** 043 * Factory method to create a transforming sorted set. 044 * <p> 045 * If there are any elements already in the set being decorated, they 046 * are NOT transformed. 047 * Contrast this with {@link #transformedSortedSet(SortedSet, Transformer)}. 048 * 049 * @param <E> the element type 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 * @return a new transformed {@link SortedSet} 053 * @throws NullPointerException if set or transformer is null 054 * @since 4.0 055 */ 056 public static <E> TransformedSortedSet<E> transformingSortedSet(final SortedSet<E> set, 057 final Transformer<? super E, ? extends E> transformer) { 058 return new TransformedSortedSet<>(set, transformer); 059 } 060 061 /** 062 * Factory method to create a transforming sorted set that will transform 063 * existing contents of the specified sorted set. 064 * <p> 065 * If there are any elements already in the set being decorated, they 066 * will be transformed by this method. 067 * Contrast this with {@link #transformingSortedSet(SortedSet, Transformer)}. 068 * 069 * @param <E> the element type 070 * @param set the set to decorate, must not be null 071 * @param transformer the transformer to use for conversion, must not be null 072 * @return a new transformed {@link SortedSet} 073 * @throws NullPointerException if set or transformer is null 074 * @since 4.0 075 */ 076 public static <E> TransformedSortedSet<E> transformedSortedSet(final SortedSet<E> set, 077 final Transformer<? super E, ? extends E> transformer) { 078 079 final TransformedSortedSet<E> decorated = new TransformedSortedSet<>(set, transformer); 080 if (set.size() > 0) { 081 @SuppressWarnings("unchecked") // set is type E 082 final E[] values = (E[]) set.toArray(); // NOPMD - false positive for generics 083 set.clear(); 084 for (final E value : values) { 085 decorated.decorated().add(transformer.transform(value)); 086 } 087 } 088 return decorated; 089 } 090 091 //----------------------------------------------------------------------- 092 /** 093 * Constructor that wraps (not copies). 094 * <p> 095 * If there are any elements already in the set being decorated, they 096 * are NOT transformed. 097 * 098 * @param set the set to decorate, must not be null 099 * @param transformer the transformer to use for conversion, must not be null 100 * @throws NullPointerException if set or transformer is null 101 */ 102 protected TransformedSortedSet(final SortedSet<E> set, final Transformer<? super E, ? extends E> transformer) { 103 super(set, transformer); 104 } 105 106 /** 107 * Gets the decorated set. 108 * 109 * @return the decorated set 110 */ 111 protected SortedSet<E> getSortedSet() { 112 return (SortedSet<E>) decorated(); 113 } 114 115 //----------------------------------------------------------------------- 116 @Override 117 public E first() { 118 return getSortedSet().first(); 119 } 120 121 @Override 122 public E last() { 123 return getSortedSet().last(); 124 } 125 126 @Override 127 public Comparator<? super E> comparator() { 128 return getSortedSet().comparator(); 129 } 130 131 //----------------------------------------------------------------------- 132 @Override 133 public SortedSet<E> subSet(final E fromElement, final E toElement) { 134 final SortedSet<E> set = getSortedSet().subSet(fromElement, toElement); 135 return new TransformedSortedSet<>(set, transformer); 136 } 137 138 @Override 139 public SortedSet<E> headSet(final E toElement) { 140 final SortedSet<E> set = getSortedSet().headSet(toElement); 141 return new TransformedSortedSet<>(set, transformer); 142 } 143 144 @Override 145 public SortedSet<E> tailSet(final E fromElement) { 146 final SortedSet<E> set = getSortedSet().tailSet(fromElement); 147 return new TransformedSortedSet<>(set, transformer); 148 } 149 150}