| /* |
| * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * Portions Copyright (c) 2011 IBM Corporation |
| */ |
| |
| /* |
| * @test |
| * @bug 7014637 |
| * @summary EnumSet's iterator.remove() can be resilient to set's modification. |
| * @author Neil Richards <neil.richards@ngmr.net>, <neil_richards@uk.ibm.com> |
| */ |
| |
| import java.util.EnumSet; |
| import java.util.Iterator; |
| import java.util.Set; |
| |
| public class LargeEnumIteratorRemoveResilience { |
| // enum with more than 64 values |
| private static enum LargeEnum { |
| e00, e01, e02, e03, e04, e05, e06, e07, |
| e08, e09, e0A, e0B, e0C, e0D, e0E, e0F, |
| e10, e11, e12, e13, e14, e15, e16, e17, |
| e18, e19, e1A, e1B, e1C, e1D, e1E, e1F, |
| e20, e21, e22, e23, e24, e25, e26, e27, |
| e28, e29, e2A, e2B, e2C, e2D, e2E, e2F, |
| e30, e31, e32, e33, e34, e35, e36, e37, |
| e38, e39, e3A, e3B, e3C, e3D, e3E, e3F, |
| e40, e41, e42, e43, e44, e45, e46, e47, |
| e48, e49, e4A, e4B, e4C, e4D, e4E, e4F, |
| } |
| |
| public static void main(final String[] args) throws Exception { |
| final Set<LargeEnum> set = EnumSet.noneOf(LargeEnum.class); |
| |
| set.add(LargeEnum.e2D); |
| set.add(LargeEnum.e42); |
| |
| final Iterator<LargeEnum> iterator = set.iterator(); |
| |
| int size = set.size(); |
| LargeEnum element = iterator.next(); |
| |
| iterator.remove(); |
| checkSetAfterRemoval(set, size, element); |
| |
| size = set.size(); |
| element = iterator.next(); |
| |
| set.remove(element); |
| checkSetAfterRemoval(set, size, element); |
| |
| // The Java API declares that the behaviour here - to call |
| // iterator.remove() after the underlying collection has been |
| // modified - is "unspecified". |
| // However, in the case of iterators for EnumSet, it is easy to |
| // implement their remove() operation such that the set is |
| // unmodified if it is called for an element that has already been |
| // removed from the set - this being the naturally "resilient" |
| // behaviour. |
| iterator.remove(); |
| checkSetAfterRemoval(set, size, element); |
| } |
| |
| private static void checkSetAfterRemoval(final Set<LargeEnum> set, |
| final int origSize, final LargeEnum removedElement) |
| throws Exception { |
| if (set.size() != (origSize - 1)) { |
| throw new Exception("Test FAILED: Unexpected set size after removal; expected '" + (origSize - 1) + "' but found '" + set.size() + "'"); |
| } |
| if (set.contains(removedElement)) { |
| throw new Exception("Test FAILED: Element returned from iterator unexpectedly still in set after removal."); |
| } |
| } |
| } |