2362N/A * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2362N/A * or visit www.oracle.com if you need additional information or have any 0N/A * This class provides a skeletal implementation of the <tt>Set</tt> 0N/A * interface to minimize the effort required to implement this 0N/A * The process of implementing a set by extending this class is identical 0N/A * to that of implementing a Collection by extending AbstractCollection, 0N/A * except that all of the methods and constructors in subclasses of this 0N/A * class must obey the additional constraints imposed by the <tt>Set</tt> 0N/A * interface (for instance, the add method must not permit addition of 0N/A * multiple instances of an object to a set).<p> 0N/A * Note that this class does not override any of the implementations from 0N/A * the <tt>AbstractCollection</tt> class. It merely adds implementations 0N/A * for <tt>equals</tt> and <tt>hashCode</tt>.<p> 0N/A * This class is a member of the 0N/A * Java Collections Framework</a>. 0N/A * @param <E> the type of elements maintained by this set 0N/A * @author Josh Bloch 0N/A * @author Neal Gafter 0N/A * @see AbstractCollection 0N/A * Sole constructor. (For invocation by subclass constructors, typically 0N/A // Comparison and hashing 0N/A * Compares the specified object with this set for equality. Returns 0N/A * <tt>true</tt> if the given object is also a set, the two sets have 0N/A * the same size, and every member of the given set is contained in 0N/A * this set. This ensures that the <tt>equals</tt> method works 0N/A * properly across different implementations of the <tt>Set</tt> 0N/A * This implementation first checks if the specified object is this 0N/A * set; if so it returns <tt>true</tt>. Then, it checks if the 0N/A * specified object is a set whose size is identical to the size of 0N/A * this set; if not, it returns false. If so, it returns 0N/A * <tt>containsAll((Collection) o)</tt>. 0N/A * @param o object to be compared for equality with this set 0N/A * @return <tt>true</tt> if the specified object is equal to this set 0N/A * Returns the hash code value for this set. The hash code of a set is 0N/A * defined to be the sum of the hash codes of the elements in the set, 0N/A * where the hash code of a <tt>null</tt> element is defined to be zero. 0N/A * This ensures that <tt>s1.equals(s2)</tt> implies that 0N/A * <tt>s1.hashCode()==s2.hashCode()</tt> for any two sets <tt>s1</tt> 0N/A * and <tt>s2</tt>, as required by the general contract of 0N/A * {@link Object#hashCode}. 0N/A * <p>This implementation iterates over the set, calling the 0N/A * <tt>hashCode</tt> method on each element in the set, and adding up 0N/A * @return the hash code value for this set 0N/A * @see Object#equals(Object) 0N/A * @see Set#equals(Object) 0N/A * Removes from this set all of its elements that are contained in the 0N/A * specified collection (optional operation). If the specified 0N/A * collection is also a set, this operation effectively modifies this 0N/A * set so that its value is the <i>asymmetric set difference</i> of 0N/A * <p>This implementation determines which is the smaller of this set 0N/A * and the specified collection, by invoking the <tt>size</tt> 0N/A * method on each. If this set has fewer elements, then the 0N/A * implementation iterates over this set, checking each element 0N/A * returned by the iterator in turn to see if it is contained in 0N/A * the specified collection. If it is so contained, it is removed 0N/A * from this set with the iterator's <tt>remove</tt> method. If 0N/A * the specified collection has fewer elements, then the 0N/A * implementation iterates over the specified collection, removing 0N/A * from this set each element returned by the iterator, using this 0N/A * set's <tt>remove</tt> method. 0N/A * <p>Note that this implementation will throw an 0N/A * <tt>UnsupportedOperationException</tt> if the iterator returned by the 0N/A * <tt>iterator</tt> method does not implement the <tt>remove</tt> method. 0N/A * @param c collection containing elements to be removed from this set 0N/A * @return <tt>true</tt> if this set changed as a result of the call 0N/A * @throws UnsupportedOperationException if the <tt>removeAll</tt> operation 0N/A * is not supported by this set 0N/A * @throws ClassCastException if the class of an element of this set 4106N/A * is incompatible with the specified collection 0N/A * @throws NullPointerException if this set contains a null element and the 4106N/A * specified collection does not permit null elements 0N/A * or if the specified collection is null 0N/A * @see #remove(Object) 0N/A * @see #contains(Object)