1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.collections.set; 18 19 import java.util.Comparator; 20 import java.util.SortedSet; 21 22 import org.apache.commons.collections.Predicate; 23 24 /** 25 * Decorates another <code>SortedSet</code> to validate that all additions 26 * match a specified predicate. 27 * <p> 28 * This set exists to provide validation for the decorated set. 29 * It is normally created to decorate an empty set. 30 * If an object cannot be added to the set, an IllegalArgumentException is thrown. 31 * <p> 32 * One usage would be to ensure that no null entries are added to the set. 33 * <pre>SortedSet set = PredicatedSortedSet.decorate(new TreeSet(), NotNullPredicate.INSTANCE);</pre> 34 * <p> 35 * This class is Serializable from Commons Collections 3.1. 36 * 37 * @since Commons Collections 3.0 38 * @version $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $ 39 * 40 * @author Stephen Colebourne 41 * @author Paul Jack 42 */ 43 public class PredicatedSortedSet extends PredicatedSet implements SortedSet { 44 45 /** Serialization version */ 46 private static final long serialVersionUID = -9110948148132275052L; 47 48 /** 49 * Factory method to create a predicated (validating) sorted set. 50 * <p> 51 * If there are any elements already in the set being decorated, they 52 * are validated. 53 * 54 * @param set the set to decorate, must not be null 55 * @param predicate the predicate to use for validation, must not be null 56 * @throws IllegalArgumentException if set or predicate is null 57 * @throws IllegalArgumentException if the set contains invalid elements 58 */ decorate(SortedSet set, Predicate predicate)59 public static SortedSet decorate(SortedSet set, Predicate predicate) { 60 return new PredicatedSortedSet(set, predicate); 61 } 62 63 //----------------------------------------------------------------------- 64 /** 65 * Constructor that wraps (not copies). 66 * <p> 67 * If there are any elements already in the set being decorated, they 68 * are validated. 69 * 70 * @param set the set to decorate, must not be null 71 * @param predicate the predicate to use for validation, must not be null 72 * @throws IllegalArgumentException if set or predicate is null 73 * @throws IllegalArgumentException if the set contains invalid elements 74 */ PredicatedSortedSet(SortedSet set, Predicate predicate)75 protected PredicatedSortedSet(SortedSet set, Predicate predicate) { 76 super(set, predicate); 77 } 78 79 /** 80 * Gets the sorted set being decorated. 81 * 82 * @return the decorated sorted set 83 */ getSortedSet()84 private SortedSet getSortedSet() { 85 return (SortedSet) getCollection(); 86 } 87 88 //----------------------------------------------------------------------- subSet(Object fromElement, Object toElement)89 public SortedSet subSet(Object fromElement, Object toElement) { 90 SortedSet sub = getSortedSet().subSet(fromElement, toElement); 91 return new PredicatedSortedSet(sub, predicate); 92 } 93 headSet(Object toElement)94 public SortedSet headSet(Object toElement) { 95 SortedSet sub = getSortedSet().headSet(toElement); 96 return new PredicatedSortedSet(sub, predicate); 97 } 98 tailSet(Object fromElement)99 public SortedSet tailSet(Object fromElement) { 100 SortedSet sub = getSortedSet().tailSet(fromElement); 101 return new PredicatedSortedSet(sub, predicate); 102 } 103 first()104 public Object first() { 105 return getSortedSet().first(); 106 } 107 last()108 public Object last() { 109 return getSortedSet().last(); 110 } 111 comparator()112 public Comparator comparator() { 113 return getSortedSet().comparator(); 114 } 115 116 } 117