11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2007 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.collect; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.annotations.GwtCompatible; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport junit.framework.TestCase; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.Iterator; 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.util.NoSuchElementException; 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unit test for {@code AbstractIterator}. 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Kevin Bourrillion 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@SuppressWarnings("serial") // No serialization is used in this test 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert@GwtCompatible 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert// TODO(cpovirk): why is this slow (>1m/test) under GWT when fully optimized? 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpublic class AbstractIteratorTest extends TestCase { 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testDefaultBehaviorOfNextAndHasNext() { 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // This sample AbstractIterator returns 0 on the first call, 1 on the 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // second, then signals that it's reached the end of the data 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Iterator<Integer> iter = new AbstractIterator<Integer>() { 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private int rep; 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Integer computeNext() { 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert switch (rep++) { 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert case 0: 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return 0; 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert case 1: 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return 1; 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert case 2: 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return endOfData(); 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert default: 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("Should not have been invoked again"); 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return null; 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertTrue(iter.hasNext()); 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(0, (int) iter.next()); 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // verify idempotence of hasNext() 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertTrue(iter.hasNext()); 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertTrue(iter.hasNext()); 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertTrue(iter.hasNext()); 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(1, (int) iter.next()); 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertFalse(iter.hasNext()); 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // Make sure computeNext() doesn't get invoked again 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertFalse(iter.hasNext()); 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.next(); 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("no exception thrown"); 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchElementException expected) { 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testDefaultBehaviorOfPeek() { 791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /* 801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * This sample AbstractIterator returns 0 on the first call, 1 on the 811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * second, then signals that it's reached the end of the data 821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert AbstractIterator<Integer> iter = new AbstractIterator<Integer>() { 841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private int rep; 851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Integer computeNext() { 861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert switch (rep++) { 871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert case 0: 881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return 0; 891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert case 1: 901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return 1; 911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert case 2: 921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return endOfData(); 931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert default: 941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("Should not have been invoked again"); 951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return null; 961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(0, (int) iter.peek()); 1011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(0, (int) iter.peek()); 1021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertTrue(iter.hasNext()); 1031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(0, (int) iter.peek()); 1041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(0, (int) iter.next()); 1051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(1, (int) iter.peek()); 1071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(1, (int) iter.next()); 1081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.peek(); 1111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("peek() should throw NoSuchElementException at end"); 1121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchElementException expected) { 1131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.peek(); 1171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("peek() should continue to throw NoSuchElementException at end"); 1181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchElementException expected) { 1191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.next(); 1231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("next() should throw NoSuchElementException as usual"); 1241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchElementException expected) { 1251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.peek(); 1291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("peek() should still throw NoSuchElementException after next()"); 1301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchElementException expected) { 1311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testDefaultBehaviorOfPeekForEmptyIteration() { 1351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert AbstractIterator<Integer> empty = new AbstractIterator<Integer>() { 1371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private boolean alreadyCalledEndOfData; 1381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Integer computeNext() { 1391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (alreadyCalledEndOfData) { 1401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("Should not have been invoked again"); 1411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert alreadyCalledEndOfData = true; 1431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return endOfData(); 1441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 1461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert empty.peek(); 1491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("peek() should throw NoSuchElementException at end"); 1501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchElementException expected) { 1511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert empty.peek(); 1551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("peek() should continue to throw NoSuchElementException at end"); 1561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (NoSuchElementException expected) { 1571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testSneakyThrow() throws Exception { 1611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Iterator<Integer> iter = new AbstractIterator<Integer>() { 1621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean haveBeenCalled; 1631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Integer computeNext() { 1641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (haveBeenCalled) { 1651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("Should not have been called again"); 1661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } else { 1671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert haveBeenCalled = true; 1681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert sneakyThrow(new SomeCheckedException()); 1691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return null; // never reached 1711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 1731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // The first time, the sneakily-thrown exception comes out 1751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.hasNext(); 1771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("No exception thrown"); 1781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (Exception e) { 1791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (!(e instanceof SomeCheckedException)) { 1801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw e; 1811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // But the second time, AbstractIterator itself throws an ISE 1851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 1861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.hasNext(); 1871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("No exception thrown"); 1881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (IllegalStateException expected) { 1891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 1921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testException() { 1931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert final SomeUncheckedException exception = new SomeUncheckedException(); 1941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Iterator<Integer> iter = new AbstractIterator<Integer>() { 1951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Integer computeNext() { 1961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw exception; 1971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 1981d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 1991d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2001d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // It should pass through untouched 2011d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 2021d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.hasNext(); 2031d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("No exception thrown"); 2041d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (SomeUncheckedException e) { 2051d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertSame(exception, e); 2061d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2071d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2081d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2091d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testExceptionAfterEndOfData() { 2101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Iterator<Integer> iter = new AbstractIterator<Integer>() { 2111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Integer computeNext() { 2121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert endOfData(); 2131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new SomeUncheckedException(); 2141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 2161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 2171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.hasNext(); 2181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("No exception thrown"); 2191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (SomeUncheckedException expected) { 2201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testCantRemove() { 2241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Iterator<Integer> iter = new AbstractIterator<Integer>() { 2251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert boolean haveBeenCalled; 2261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override public Integer computeNext() { 2271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (haveBeenCalled) { 2281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert endOfData(); 2291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert haveBeenCalled = true; 2311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return 0; 2321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 2341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert assertEquals(0, (int) iter.next()); 2361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 2381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.remove(); 2391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail("No exception thrown"); 2401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (UnsupportedOperationException expected) { 2411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public void testReentrantHasNext() { 2451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Iterator<Integer> iter = new AbstractIterator<Integer>() { 2461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override protected Integer computeNext() { 2471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert hasNext(); 2481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return null; 2491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert }; 2511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert try { 2521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert iter.hasNext(); 2531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert fail(); 2541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } catch (IllegalStateException expected) { 2551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // Technically we should test other reentrant scenarios (9 combinations of 2591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // hasNext/next/peek), but we'll cop out for now, knowing that peek() and 2601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert // next() both start by invoking hasNext() anyway. 2611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 2631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Throws a undeclared checked exception. 2641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 2651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static void sneakyThrow(Throwable t) { 2661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert class SneakyThrower<T extends Throwable> { 2671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @SuppressWarnings("unchecked") // not really safe, but that's the point 2681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert void throwIt(Throwable t) throws T { 2691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw (T) t; 2701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert new SneakyThrower<Error>().throwIt(t); 2731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static class SomeCheckedException extends Exception { 2761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 2781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static class SomeUncheckedException extends RuntimeException { 2791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 2801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 281