AbstractSet.java revision 3819a76e7c1f49253f0e077bd497f149340c02b8
1f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project/* 2f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Licensed to the Apache Software Foundation (ASF) under one or more 3f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * contributor license agreements. See the NOTICE file distributed with 4f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * this work for additional information regarding copyright ownership. 5f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * The ASF licenses this file to You under the Apache License, Version 2.0 6f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * (the "License"); you may not use this file except in compliance with 7f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the License. You may obtain a copy of the License at 8f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 9f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 10f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 11f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 12f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 13f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * See the License for the specific language governing permissions and 15f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * limitations under the License. 16f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 17f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 18f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectpackage java.util; 19f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 20f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project/** 21f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * An AbstractSet is an abstract implementation of the Set interface. This 22f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * implementation does not support adding. A subclass must implement the 23f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * abstract methods iterator() and size(). 24f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 253819a76e7c1f49253f0e077bd497f149340c02b8Jesse Wilson * @since 1.2 26f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 27f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectpublic abstract class AbstractSet<E> extends AbstractCollection<E> implements 28f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project Set<E> { 29f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 30f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 31f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Constructs a new instance of this AbstractSet. 32f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 33f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project protected AbstractSet() { 34f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project super(); 35f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 36f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 37f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 38f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Compares the specified object to this Set and returns true if they are 39f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * equal. The object must be an instance of Set and contain the same 40f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * objects. 41f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 42f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @param object 43f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the object to compare with this set. 44f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @return {@code true} if the specified object is equal to this set, 45f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * {@code false} otherwise 46f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @see #hashCode 47f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 48f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project @Override 49f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public boolean equals(Object object) { 50f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (this == object) { 51f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return true; 52f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 53f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (object instanceof Set) { 54f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project Set<?> s = (Set<?>) object; 553819a76e7c1f49253f0e077bd497f149340c02b8Jesse Wilson 56f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project try { 57f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return size() == s.size() && containsAll(s); 58f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } catch (ClassCastException cce) { 59f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return false; 60f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 61f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 62f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return false; 63f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 64f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 65f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 66f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Returns the hash code for this set. Two set which are equal must return 67f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the same value. This implementation calculates the hash code by adding 68f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * each element's hash code. 69f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 70f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @return the hash code of this set. 71f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @see #equals 72f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 73f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project @Override 74f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public int hashCode() { 75f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project int result = 0; 76f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project Iterator<?> it = iterator(); 77f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project while (it.hasNext()) { 78f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project Object next = it.next(); 79f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project result += next == null ? 0 : next.hashCode(); 80f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 81f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return result; 82f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 83f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 84f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 85f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Removes all occurrences in this collection which are contained in the 86f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * specified collection. 87f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 88f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @param collection 89f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the collection of objects to remove. 90f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @return {@code true} if this collection was modified, {@code false} 91f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * otherwise. 923819a76e7c1f49253f0e077bd497f149340c02b8Jesse Wilson * @throws UnsupportedOperationException 933819a76e7c1f49253f0e077bd497f149340c02b8Jesse Wilson * if removing from this collection is not supported. 94f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 95f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project @Override 96f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public boolean removeAll(Collection<?> collection) { 97f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project boolean result = false; 98f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (size() <= collection.size()) { 99f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project Iterator<?> it = iterator(); 100f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project while (it.hasNext()) { 101f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (collection.contains(it.next())) { 102f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project it.remove(); 103f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project result = true; 104f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 105f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 106f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } else { 107f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project Iterator<?> it = collection.iterator(); 108f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project while (it.hasNext()) { 109f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project result = remove(it.next()) || result; 110f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 111f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 112f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return result; 113f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 114f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project} 115