1 /* 2 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* 25 * Portions Copyright (c) 2011 IBM Corporation 26 */ 27 28 /* 29 * @test 30 * @bug 7014637 31 * @summary EnumSet's iterator.remove() can be resilient to set's modification. 32 * @author Neil Richards <neil.richards@ngmr.net>, <neil_richards@uk.ibm.com> 33 */ 34 package test.java.util.EnumSet; 35 36 37 import java.util.EnumSet; 38 import java.util.Iterator; 39 import java.util.Set; 40 41 public class LargeEnumIteratorRemoveResilience { 42 // enum with more than 64 values 43 private static enum LargeEnum { 44 e00, e01, e02, e03, e04, e05, e06, e07, 45 e08, e09, e0A, e0B, e0C, e0D, e0E, e0F, 46 e10, e11, e12, e13, e14, e15, e16, e17, 47 e18, e19, e1A, e1B, e1C, e1D, e1E, e1F, 48 e20, e21, e22, e23, e24, e25, e26, e27, 49 e28, e29, e2A, e2B, e2C, e2D, e2E, e2F, 50 e30, e31, e32, e33, e34, e35, e36, e37, 51 e38, e39, e3A, e3B, e3C, e3D, e3E, e3F, 52 e40, e41, e42, e43, e44, e45, e46, e47, 53 e48, e49, e4A, e4B, e4C, e4D, e4E, e4F, 54 } 55 main(final String[] args)56 public static void main(final String[] args) throws Exception { 57 final Set<LargeEnum> set = EnumSet.noneOf(LargeEnum.class); 58 59 set.add(LargeEnum.e2D); 60 set.add(LargeEnum.e42); 61 62 final Iterator<LargeEnum> iterator = set.iterator(); 63 64 int size = set.size(); 65 LargeEnum element = iterator.next(); 66 67 iterator.remove(); 68 checkSetAfterRemoval(set, size, element); 69 70 size = set.size(); 71 element = iterator.next(); 72 73 set.remove(element); 74 checkSetAfterRemoval(set, size, element); 75 76 // The Java API declares that the behaviour here - to call 77 // iterator.remove() after the underlying collection has been 78 // modified - is "unspecified". 79 // However, in the case of iterators for EnumSet, it is easy to 80 // implement their remove() operation such that the set is 81 // unmodified if it is called for an element that has already been 82 // removed from the set - this being the naturally "resilient" 83 // behaviour. 84 iterator.remove(); 85 checkSetAfterRemoval(set, size, element); 86 } 87 checkSetAfterRemoval(final Set<LargeEnum> set, final int origSize, final LargeEnum removedElement)88 private static void checkSetAfterRemoval(final Set<LargeEnum> set, 89 final int origSize, final LargeEnum removedElement) 90 throws Exception { 91 if (set.size() != (origSize - 1)) { 92 throw new Exception("Test FAILED: Unexpected set size after removal; expected '" + (origSize - 1) + "' but found '" + set.size() + "'"); 93 } 94 if (set.contains(removedElement)) { 95 throw new Exception("Test FAILED: Element returned from iterator unexpectedly still in set after removal."); 96 } 97 } 98 } 99