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.collections4.multiset; 18 19 import java.util.Set; 20 21 import org.apache.commons.collections4.MultiSet; 22 import org.apache.commons.collections4.Predicate; 23 import org.apache.commons.collections4.collection.PredicatedCollection; 24 25 /** 26 * Decorates another {@link MultiSet} to validate that additions 27 * match a specified predicate. 28 * <p> 29 * This multiset exists to provide validation for the decorated multiset. 30 * It is normally created to decorate an empty multiset. 31 * If an object cannot be added to the multiset, an {@link IllegalArgumentException} 32 * is thrown. 33 * </p> 34 * <p> 35 * One usage would be to ensure that no null entries are added to the multiset. 36 * </p> 37 * <pre> 38 * MultiSet<E> set = 39 * PredicatedMultiSet.predicatedMultiSet(new HashMultiSet<E>(), 40 * NotNullPredicate.notNullPredicate()); 41 * </pre> 42 * 43 * @param <E> the type held in the multiset 44 * @since 4.1 45 */ 46 public class PredicatedMultiSet<E> extends PredicatedCollection<E> implements MultiSet<E> { 47 48 /** Serialization version */ 49 private static final long serialVersionUID = 20150629L; 50 51 /** 52 * Factory method to create a predicated (validating) multiset. 53 * <p> 54 * If there are any elements already in the multiset being decorated, they 55 * are validated. 56 * 57 * @param <E> the type of the elements in the multiset 58 * @param multiset the multiset to decorate, must not be null 59 * @param predicate the predicate to use for validation, must not be null 60 * @return a new predicated MultiSet 61 * @throws NullPointerException if multiset or predicate is null 62 * @throws IllegalArgumentException if the multiset contains invalid elements 63 */ 64 public static <E> PredicatedMultiSet<E> predicatedMultiSet(final MultiSet<E> multiset, 65 final Predicate<? super E> predicate) { 66 return new PredicatedMultiSet<>(multiset, predicate); 67 } 68 69 /** 70 * Constructor that wraps (not copies). 71 * <p> 72 * If there are any elements already in the multiset being decorated, they 73 * are validated. 74 * 75 * @param multiset the multiset to decorate, must not be null 76 * @param predicate the predicate to use for validation, must not be null 77 * @throws NullPointerException if multiset or predicate is null 78 * @throws IllegalArgumentException if the multiset contains invalid elements 79 */ 80 protected PredicatedMultiSet(final MultiSet<E> multiset, final Predicate<? super E> predicate) { 81 super(multiset, predicate); 82 } 83 84 @Override 85 public int add(final E object, final int count) { 86 validate(object); 87 return decorated().add(object, count); 88 } 89 90 /** 91 * Gets the decorated multiset. 92 * 93 * @return the decorated multiset 94 */ 95 @Override 96 protected MultiSet<E> decorated() { 97 return (MultiSet<E>) super.decorated(); 98 } 99 100 @Override 101 public Set<MultiSet.Entry<E>> entrySet() { 102 return decorated().entrySet(); 103 } 104 105 @Override 106 public boolean equals(final Object object) { 107 return object == this || decorated().equals(object); 108 } 109 110 @Override 111 public int getCount(final Object object) { 112 return decorated().getCount(object); 113 } 114 115 @Override 116 public int hashCode() { 117 return decorated().hashCode(); 118 } 119 120 @Override 121 public int remove(final Object object, final int count) { 122 return decorated().remove(object, count); 123 } 124 125 @Override 126 public int setCount(final E object, final int count) { 127 validate(object); 128 return decorated().setCount(object, count); 129 } 130 131 @Override 132 public Set<E> uniqueSet() { 133 return decorated().uniqueSet(); 134 } 135 136 }