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.Predicate; 023 024/** 025 * Decorates another <code>SortedSet</code> to validate that all additions 026 * match a specified predicate. 027 * <p> 028 * This set exists to provide validation for the decorated set. 029 * It is normally created to decorate an empty set. 030 * If an object cannot be added to the set, an IllegalArgumentException is thrown. 031 * </p> 032 * <p> 033 * One usage would be to ensure that no null entries are added to the set. 034 * </p> 035 * <pre> 036 * SortedSet set = 037 * PredicatedSortedSet.predicatedSortedSet(new TreeSet(), 038 * NotNullPredicate.notNullPredicate()); 039 * </pre> 040 * <p> 041 * This class is Serializable from Commons Collections 3.1. 042 * </p> 043 * 044 * @param <E> the type of the elements in this set 045 * @since 3.0 046 */ 047public class PredicatedSortedSet<E> extends PredicatedSet<E> implements SortedSet<E> { 048 049 /** Serialization version */ 050 private static final long serialVersionUID = -9110948148132275052L; 051 052 /** 053 * Factory method to create a predicated (validating) sorted set. 054 * <p> 055 * If there are any elements already in the set being decorated, they 056 * are validated. 057 * 058 * @param <E> the element type 059 * @param set the set to decorate, must not be null 060 * @param predicate the predicate to use for validation, must not be null 061 * @return a new predicated sorted set. 062 * @throws NullPointerException if set or predicate is null 063 * @throws IllegalArgumentException if the set contains invalid elements 064 * @since 4.0 065 */ 066 public static <E> PredicatedSortedSet<E> predicatedSortedSet(final SortedSet<E> set, 067 final Predicate<? super E> predicate) { 068 return new PredicatedSortedSet<>(set, predicate); 069 } 070 071 //----------------------------------------------------------------------- 072 /** 073 * Constructor that wraps (not copies). 074 * <p> 075 * If there are any elements already in the set being decorated, they 076 * are validated. 077 * 078 * @param set the set to decorate, must not be null 079 * @param predicate the predicate to use for validation, must not be null 080 * @throws NullPointerException if set or predicate is null 081 * @throws IllegalArgumentException if the set contains invalid elements 082 */ 083 protected PredicatedSortedSet(final SortedSet<E> set, final Predicate<? super E> predicate) { 084 super(set, predicate); 085 } 086 087 /** 088 * Gets the sorted set being decorated. 089 * 090 * @return the decorated sorted set 091 */ 092 @Override 093 protected SortedSet<E> decorated() { 094 return (SortedSet<E>) super.decorated(); 095 } 096 097 //----------------------------------------------------------------------- 098 @Override 099 public Comparator<? super E> comparator() { 100 return decorated().comparator(); 101 } 102 103 @Override 104 public E first() { 105 return decorated().first(); 106 } 107 108 @Override 109 public E last() { 110 return decorated().last(); 111 } 112 113 @Override 114 public SortedSet<E> subSet(final E fromElement, final E toElement) { 115 final SortedSet<E> sub = decorated().subSet(fromElement, toElement); 116 return new PredicatedSortedSet<>(sub, predicate); 117 } 118 119 @Override 120 public SortedSet<E> headSet(final E toElement) { 121 final SortedSet<E> head = decorated().headSet(toElement); 122 return new PredicatedSortedSet<>(head, predicate); 123 } 124 125 @Override 126 public SortedSet<E> tailSet(final E fromElement) { 127 final SortedSet<E> tail = decorated().tailSet(fromElement); 128 return new PredicatedSortedSet<>(tail, predicate); 129 } 130 131}