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.set; 18 19 import java.util.Set; 20 21 import org.apache.commons.collections4.collection.AbstractCollectionDecorator; 22 23 /** 24 * Decorates another {@code Set} to provide additional behavior. 25 * <p> 26 * Methods are forwarded directly to the decorated set. 27 * </p> 28 * 29 * @param <E> the type of the elements in this set 30 * @since 3.0 31 */ 32 public abstract class AbstractSetDecorator<E> extends AbstractCollectionDecorator<E> implements 33 Set<E> { 34 35 /** Serialization version */ 36 private static final long serialVersionUID = -4678668309576958546L; 37 38 /** 39 * Constructor only used in deserialization, do not use otherwise. 40 * @since 3.1 41 */ 42 protected AbstractSetDecorator() { 43 } 44 45 /** 46 * Constructor that wraps (not copies). 47 * 48 * @param set the set to decorate, must not be null 49 * @throws NullPointerException if set is null 50 */ 51 protected AbstractSetDecorator(final Set<E> set) { 52 super(set); 53 } 54 55 /** 56 * Gets the set being decorated. 57 * 58 * @return the decorated set 59 */ 60 @Override 61 protected Set<E> decorated() { 62 return (Set<E>) super.decorated(); 63 } 64 65 @Override 66 public boolean equals(final Object object) { 67 return object == this || decorated().equals(object); 68 } 69 70 @Override 71 public int hashCode() { 72 return decorated().hashCode(); 73 } 74 75 }