1/* 2 * Copyright (c) 2012, 2015, 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 */ 23package org.openjdk.tests.java.util.stream; 24 25import java.util.ArrayList; 26import java.util.Arrays; 27import java.util.Collection; 28import java.util.Collections; 29import java.util.Comparator; 30import java.util.HashMap; 31import java.util.HashSet; 32import java.util.Iterator; 33import java.util.List; 34import java.util.Map; 35import java.util.Optional; 36import java.util.Set; 37import java.util.StringJoiner; 38import java.util.TreeMap; 39import java.util.concurrent.ConcurrentHashMap; 40import java.util.concurrent.ConcurrentSkipListMap; 41import java.util.concurrent.atomic.AtomicInteger; 42import java.util.function.BinaryOperator; 43import java.util.function.Function; 44import java.util.function.Predicate; 45import java.util.function.Supplier; 46import java.util.stream.Collector; 47import java.util.stream.Collectors; 48import java.util.stream.LambdaTestHelpers; 49import java.util.stream.OpTestCase; 50import java.util.stream.Stream; 51import java.util.stream.StreamOpFlagTestHelper; 52import java.util.stream.StreamTestDataProvider; 53import java.util.stream.TestData; 54 55import org.testng.annotations.Test; 56 57import static java.util.stream.Collectors.collectingAndThen; 58import static java.util.stream.Collectors.flatMapping; 59import static java.util.stream.Collectors.filtering; 60import static java.util.stream.Collectors.groupingBy; 61import static java.util.stream.Collectors.groupingByConcurrent; 62import static java.util.stream.Collectors.mapping; 63import static java.util.stream.Collectors.partitioningBy; 64import static java.util.stream.Collectors.reducing; 65import static java.util.stream.Collectors.toCollection; 66import static java.util.stream.Collectors.toConcurrentMap; 67import static java.util.stream.Collectors.toList; 68import static java.util.stream.Collectors.toMap; 69import static java.util.stream.Collectors.toSet; 70import static java.util.stream.LambdaTestHelpers.assertContents; 71import static java.util.stream.LambdaTestHelpers.assertContentsUnordered; 72import static java.util.stream.LambdaTestHelpers.mDoubler; 73 74/* 75 * @test 76 * @bug 8071600 8144675 77 * @summary Test for collectors. 78 */ 79public class CollectorsTest extends OpTestCase { 80 81 private abstract static class CollectorAssertion<T, U> { 82 abstract void assertValue(U value, 83 Supplier<Stream<T>> source, 84 boolean ordered) throws ReflectiveOperationException; 85 } 86 87 static class MappingAssertion<T, V, R> extends CollectorAssertion<T, R> { 88 private final Function<T, V> mapper; 89 private final CollectorAssertion<V, R> downstream; 90 91 MappingAssertion(Function<T, V> mapper, CollectorAssertion<V, R> downstream) { 92 this.mapper = mapper; 93 this.downstream = downstream; 94 } 95 96 @Override 97 void assertValue(R value, Supplier<Stream<T>> source, boolean ordered) throws ReflectiveOperationException { 98 downstream.assertValue(value, 99 () -> source.get().map(mapper::apply), 100 ordered); 101 } 102 } 103 104 static class FlatMappingAssertion<T, V, R> extends CollectorAssertion<T, R> { 105 private final Function<T, Stream<V>> mapper; 106 private final CollectorAssertion<V, R> downstream; 107 108 FlatMappingAssertion(Function<T, Stream<V>> mapper, 109 CollectorAssertion<V, R> downstream) { 110 this.mapper = mapper; 111 this.downstream = downstream; 112 } 113 114 @Override 115 void assertValue(R value, Supplier<Stream<T>> source, boolean ordered) throws ReflectiveOperationException { 116 downstream.assertValue(value, 117 () -> source.get().flatMap(mapper::apply), 118 ordered); 119 } 120 } 121 122 static class FilteringAssertion<T, R> extends CollectorAssertion<T, R> { 123 private final Predicate<T> filter; 124 private final CollectorAssertion<T, R> downstream; 125 126 public FilteringAssertion(Predicate<T> filter, CollectorAssertion<T, R> downstream) { 127 this.filter = filter; 128 this.downstream = downstream; 129 } 130 131 @Override 132 void assertValue(R value, Supplier<Stream<T>> source, boolean ordered) throws ReflectiveOperationException { 133 downstream.assertValue(value, 134 () -> source.get().filter(filter), 135 ordered); 136 } 137 } 138 139 static class GroupingByAssertion<T, K, V, M extends Map<K, ? extends V>> extends CollectorAssertion<T, M> { 140 private final Class<? extends Map> clazz; 141 private final Function<T, K> classifier; 142 private final CollectorAssertion<T,V> downstream; 143 144 GroupingByAssertion(Function<T, K> classifier, Class<? extends Map> clazz, 145 CollectorAssertion<T, V> downstream) { 146 this.clazz = clazz; 147 this.classifier = classifier; 148 this.downstream = downstream; 149 } 150 151 @Override 152 void assertValue(M map, 153 Supplier<Stream<T>> source, 154 boolean ordered) throws ReflectiveOperationException { 155 if (!clazz.isAssignableFrom(map.getClass())) 156 fail(String.format("Class mismatch in GroupingByAssertion: %s, %s", clazz, map.getClass())); 157 assertContentsUnordered(map.keySet(), source.get().map(classifier).collect(toSet())); 158 for (Map.Entry<K, ? extends V> entry : map.entrySet()) { 159 K key = entry.getKey(); 160 downstream.assertValue(entry.getValue(), 161 () -> source.get().filter(e -> classifier.apply(e).equals(key)), 162 ordered); 163 } 164 } 165 } 166 167 static class ToMapAssertion<T, K, V, M extends Map<K,V>> extends CollectorAssertion<T, M> { 168 private final Class<? extends Map> clazz; 169 private final Function<T, K> keyFn; 170 private final Function<T, V> valueFn; 171 private final BinaryOperator<V> mergeFn; 172 173 ToMapAssertion(Function<T, K> keyFn, 174 Function<T, V> valueFn, 175 BinaryOperator<V> mergeFn, 176 Class<? extends Map> clazz) { 177 this.clazz = clazz; 178 this.keyFn = keyFn; 179 this.valueFn = valueFn; 180 this.mergeFn = mergeFn; 181 } 182 183 @Override 184 void assertValue(M map, Supplier<Stream<T>> source, boolean ordered) throws ReflectiveOperationException { 185 if (!clazz.isAssignableFrom(map.getClass())) 186 fail(String.format("Class mismatch in ToMapAssertion: %s, %s", clazz, map.getClass())); 187 Set<K> uniqueKeys = source.get().map(keyFn).collect(toSet()); 188 assertEquals(uniqueKeys, map.keySet()); 189 source.get().forEach(t -> { 190 K key = keyFn.apply(t); 191 V v = source.get() 192 .filter(e -> key.equals(keyFn.apply(e))) 193 .map(valueFn) 194 .reduce(mergeFn) 195 .get(); 196 assertEquals(map.get(key), v); 197 }); 198 } 199 } 200 201 static class PartitioningByAssertion<T, D> extends CollectorAssertion<T, Map<Boolean,D>> { 202 private final Predicate<T> predicate; 203 private final CollectorAssertion<T,D> downstream; 204 205 PartitioningByAssertion(Predicate<T> predicate, CollectorAssertion<T, D> downstream) { 206 this.predicate = predicate; 207 this.downstream = downstream; 208 } 209 210 @Override 211 void assertValue(Map<Boolean, D> map, 212 Supplier<Stream<T>> source, 213 boolean ordered) throws ReflectiveOperationException { 214 if (!Map.class.isAssignableFrom(map.getClass())) 215 fail(String.format("Class mismatch in PartitioningByAssertion: %s", map.getClass())); 216 assertEquals(2, map.size()); 217 downstream.assertValue(map.get(true), () -> source.get().filter(predicate), ordered); 218 downstream.assertValue(map.get(false), () -> source.get().filter(predicate.negate()), ordered); 219 } 220 } 221 222 static class ToListAssertion<T> extends CollectorAssertion<T, List<T>> { 223 @Override 224 void assertValue(List<T> value, Supplier<Stream<T>> source, boolean ordered) 225 throws ReflectiveOperationException { 226 if (!List.class.isAssignableFrom(value.getClass())) 227 fail(String.format("Class mismatch in ToListAssertion: %s", value.getClass())); 228 Stream<T> stream = source.get(); 229 List<T> result = new ArrayList<>(); 230 for (Iterator<T> it = stream.iterator(); it.hasNext(); ) // avoid capturing result::add 231 result.add(it.next()); 232 if (StreamOpFlagTestHelper.isStreamOrdered(stream) && ordered) 233 assertContents(value, result); 234 else 235 assertContentsUnordered(value, result); 236 } 237 } 238 239 static class ToCollectionAssertion<T> extends CollectorAssertion<T, Collection<T>> { 240 private final Class<? extends Collection> clazz; 241 private final boolean targetOrdered; 242 243 ToCollectionAssertion(Class<? extends Collection> clazz, boolean targetOrdered) { 244 this.clazz = clazz; 245 this.targetOrdered = targetOrdered; 246 } 247 248 @Override 249 void assertValue(Collection<T> value, Supplier<Stream<T>> source, boolean ordered) 250 throws ReflectiveOperationException { 251 if (!clazz.isAssignableFrom(value.getClass())) 252 fail(String.format("Class mismatch in ToCollectionAssertion: %s, %s", clazz, value.getClass())); 253 Stream<T> stream = source.get(); 254 Collection<T> result = clazz.newInstance(); 255 for (Iterator<T> it = stream.iterator(); it.hasNext(); ) // avoid capturing result::add 256 result.add(it.next()); 257 if (StreamOpFlagTestHelper.isStreamOrdered(stream) && targetOrdered && ordered) 258 assertContents(value, result); 259 else 260 assertContentsUnordered(value, result); 261 } 262 } 263 264 static class ReducingAssertion<T, U> extends CollectorAssertion<T, U> { 265 private final U identity; 266 private final Function<T, U> mapper; 267 private final BinaryOperator<U> reducer; 268 269 ReducingAssertion(U identity, Function<T, U> mapper, BinaryOperator<U> reducer) { 270 this.identity = identity; 271 this.mapper = mapper; 272 this.reducer = reducer; 273 } 274 275 @Override 276 void assertValue(U value, Supplier<Stream<T>> source, boolean ordered) 277 throws ReflectiveOperationException { 278 Optional<U> reduced = source.get().map(mapper).reduce(reducer); 279 if (value == null) 280 assertTrue(!reduced.isPresent()); 281 else if (!reduced.isPresent()) { 282 assertEquals(value, identity); 283 } 284 else { 285 assertEquals(value, reduced.get()); 286 } 287 } 288 } 289 290 private <T> ResultAsserter<T> mapTabulationAsserter(boolean ordered) { 291 return (act, exp, ord, par) -> { 292 if (par && (!ordered || !ord)) { 293 CollectorsTest.nestedMapEqualityAssertion(act, exp); 294 } 295 else { 296 LambdaTestHelpers.assertContentsEqual(act, exp); 297 } 298 }; 299 } 300 301 private<T, M extends Map> 302 void exerciseMapCollection(TestData<T, Stream<T>> data, 303 Collector<T, ?, ? extends M> collector, 304 CollectorAssertion<T, M> assertion) 305 throws ReflectiveOperationException { 306 boolean ordered = !collector.characteristics().contains(Collector.Characteristics.UNORDERED); 307 308 M m = withData(data) 309 .terminal(s -> s.collect(collector)) 310 .resultAsserter(mapTabulationAsserter(ordered)) 311 .exercise(); 312 assertion.assertValue(m, () -> data.stream(), ordered); 313 314 m = withData(data) 315 .terminal(s -> s.unordered().collect(collector)) 316 .resultAsserter(mapTabulationAsserter(ordered)) 317 .exercise(); 318 assertion.assertValue(m, () -> data.stream(), false); 319 } 320 321 private static void nestedMapEqualityAssertion(Object o1, Object o2) { 322 if (o1 instanceof Map) { 323 Map m1 = (Map) o1; 324 Map m2 = (Map) o2; 325 assertContentsUnordered(m1.keySet(), m2.keySet()); 326 for (Object k : m1.keySet()) 327 nestedMapEqualityAssertion(m1.get(k), m2.get(k)); 328 } 329 else if (o1 instanceof Collection) { 330 assertContentsUnordered(((Collection) o1), ((Collection) o2)); 331 } 332 else 333 assertEquals(o1, o2); 334 } 335 336 private<T, R> void assertCollect(TestData.OfRef<T> data, 337 Collector<T, ?, R> collector, 338 Function<Stream<T>, R> streamReduction) { 339 R check = streamReduction.apply(data.stream()); 340 withData(data).terminal(s -> s.collect(collector)).expectedResult(check).exercise(); 341 } 342 343 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 344 public void testReducing(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 345 assertCollect(data, Collectors.reducing(0, Integer::sum), 346 s -> s.reduce(0, Integer::sum)); 347 assertCollect(data, Collectors.reducing(Integer.MAX_VALUE, Integer::min), 348 s -> s.min(Integer::compare).orElse(Integer.MAX_VALUE)); 349 assertCollect(data, Collectors.reducing(Integer.MIN_VALUE, Integer::max), 350 s -> s.max(Integer::compare).orElse(Integer.MIN_VALUE)); 351 352 assertCollect(data, Collectors.reducing(Integer::sum), 353 s -> s.reduce(Integer::sum)); 354 assertCollect(data, Collectors.minBy(Comparator.naturalOrder()), 355 s -> s.min(Integer::compare)); 356 assertCollect(data, Collectors.maxBy(Comparator.naturalOrder()), 357 s -> s.max(Integer::compare)); 358 359 assertCollect(data, Collectors.reducing(0, x -> x*2, Integer::sum), 360 s -> s.map(x -> x*2).reduce(0, Integer::sum)); 361 362 assertCollect(data, Collectors.summingLong(x -> x * 2L), 363 s -> s.map(x -> x*2L).reduce(0L, Long::sum)); 364 assertCollect(data, Collectors.summingInt(x -> x * 2), 365 s -> s.map(x -> x*2).reduce(0, Integer::sum)); 366 assertCollect(data, Collectors.summingDouble(x -> x * 2.0d), 367 s -> s.map(x -> x * 2.0d).reduce(0.0d, Double::sum)); 368 369 assertCollect(data, Collectors.averagingInt(x -> x * 2), 370 s -> s.mapToInt(x -> x * 2).average().orElse(0)); 371 assertCollect(data, Collectors.averagingLong(x -> x * 2), 372 s -> s.mapToLong(x -> x * 2).average().orElse(0)); 373 assertCollect(data, Collectors.averagingDouble(x -> x * 2), 374 s -> s.mapToDouble(x -> x * 2).average().orElse(0)); 375 376 // Test explicit Collector.of 377 Collector<Integer, long[], Double> avg2xint = Collector.of(() -> new long[2], 378 (a, b) -> { 379 a[0] += b * 2; 380 a[1]++; 381 }, 382 (a, b) -> { 383 a[0] += b[0]; 384 a[1] += b[1]; 385 return a; 386 }, 387 a -> a[1] == 0 ? 0.0d : (double) a[0] / a[1]); 388 assertCollect(data, avg2xint, 389 s -> s.mapToInt(x -> x * 2).average().orElse(0)); 390 } 391 392 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 393 public void testJoining(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 394 withData(data) 395 .terminal(s -> s.map(Object::toString).collect(Collectors.joining())) 396 .expectedResult(join(data, "")) 397 .exercise(); 398 399 Collector<String, StringBuilder, String> likeJoining = Collector.of(StringBuilder::new, StringBuilder::append, (sb1, sb2) -> sb1.append(sb2.toString()), StringBuilder::toString); 400 withData(data) 401 .terminal(s -> s.map(Object::toString).collect(likeJoining)) 402 .expectedResult(join(data, "")) 403 .exercise(); 404 405 withData(data) 406 .terminal(s -> s.map(Object::toString).collect(Collectors.joining(","))) 407 .expectedResult(join(data, ",")) 408 .exercise(); 409 410 withData(data) 411 .terminal(s -> s.map(Object::toString).collect(Collectors.joining(",", "[", "]"))) 412 .expectedResult("[" + join(data, ",") + "]") 413 .exercise(); 414 415 withData(data) 416 .terminal(s -> s.map(Object::toString) 417 .collect(StringBuilder::new, StringBuilder::append, StringBuilder::append) 418 .toString()) 419 .expectedResult(join(data, "")) 420 .exercise(); 421 422 withData(data) 423 .terminal(s -> s.map(Object::toString) 424 .collect(() -> new StringJoiner(","), 425 (sj, cs) -> sj.add(cs), 426 (j1, j2) -> j1.merge(j2)) 427 .toString()) 428 .expectedResult(join(data, ",")) 429 .exercise(); 430 431 withData(data) 432 .terminal(s -> s.map(Object::toString) 433 .collect(() -> new StringJoiner(",", "[", "]"), 434 (sj, cs) -> sj.add(cs), 435 (j1, j2) -> j1.merge(j2)) 436 .toString()) 437 .expectedResult("[" + join(data, ",") + "]") 438 .exercise(); 439 } 440 441 private<T> String join(TestData.OfRef<T> data, String delim) { 442 StringBuilder sb = new StringBuilder(); 443 boolean first = true; 444 for (T i : data) { 445 if (!first) 446 sb.append(delim); 447 sb.append(i.toString()); 448 first = false; 449 } 450 return sb.toString(); 451 } 452 453 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 454 public void testSimpleToMap(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 455 Function<Integer, Integer> keyFn = i -> i * 2; 456 Function<Integer, Integer> valueFn = i -> i * 4; 457 458 List<Integer> dataAsList = Arrays.asList(data.stream().toArray(Integer[]::new)); 459 Set<Integer> dataAsSet = new HashSet<>(dataAsList); 460 461 BinaryOperator<Integer> sum = Integer::sum; 462 for (BinaryOperator<Integer> op : Arrays.asList((u, v) -> u, 463 (u, v) -> v, 464 sum)) { 465 try { 466 exerciseMapCollection(data, toMap(keyFn, valueFn), 467 new ToMapAssertion<>(keyFn, valueFn, op, HashMap.class)); 468 if (dataAsList.size() != dataAsSet.size()) 469 fail("Expected ISE on input with duplicates"); 470 } 471 catch (IllegalStateException e) { 472 if (dataAsList.size() == dataAsSet.size()) 473 fail("Expected no ISE on input without duplicates"); 474 } 475 476 exerciseMapCollection(data, toMap(keyFn, valueFn, op), 477 new ToMapAssertion<>(keyFn, valueFn, op, HashMap.class)); 478 479 exerciseMapCollection(data, toMap(keyFn, valueFn, op, TreeMap::new), 480 new ToMapAssertion<>(keyFn, valueFn, op, TreeMap.class)); 481 } 482 483 // For concurrent maps, only use commutative merge functions 484 try { 485 exerciseMapCollection(data, toConcurrentMap(keyFn, valueFn), 486 new ToMapAssertion<>(keyFn, valueFn, sum, ConcurrentHashMap.class)); 487 if (dataAsList.size() != dataAsSet.size()) 488 fail("Expected ISE on input with duplicates"); 489 } 490 catch (IllegalStateException e) { 491 if (dataAsList.size() == dataAsSet.size()) 492 fail("Expected no ISE on input without duplicates"); 493 } 494 495 exerciseMapCollection(data, toConcurrentMap(keyFn, valueFn, sum), 496 new ToMapAssertion<>(keyFn, valueFn, sum, ConcurrentHashMap.class)); 497 498 exerciseMapCollection(data, toConcurrentMap(keyFn, valueFn, sum, ConcurrentSkipListMap::new), 499 new ToMapAssertion<>(keyFn, valueFn, sum, ConcurrentSkipListMap.class)); 500 } 501 502 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 503 public void testSimpleGroupingBy(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 504 Function<Integer, Integer> classifier = i -> i % 3; 505 506 // Single-level groupBy 507 exerciseMapCollection(data, groupingBy(classifier), 508 new GroupingByAssertion<>(classifier, HashMap.class, 509 new ToListAssertion<>())); 510 exerciseMapCollection(data, groupingByConcurrent(classifier), 511 new GroupingByAssertion<>(classifier, ConcurrentHashMap.class, 512 new ToListAssertion<>())); 513 514 // With explicit constructors 515 exerciseMapCollection(data, 516 groupingBy(classifier, TreeMap::new, toCollection(HashSet::new)), 517 new GroupingByAssertion<>(classifier, TreeMap.class, 518 new ToCollectionAssertion<Integer>(HashSet.class, false))); 519 exerciseMapCollection(data, 520 groupingByConcurrent(classifier, ConcurrentSkipListMap::new, 521 toCollection(HashSet::new)), 522 new GroupingByAssertion<>(classifier, ConcurrentSkipListMap.class, 523 new ToCollectionAssertion<Integer>(HashSet.class, false))); 524 } 525 526 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 527 public void testGroupingByWithMapping(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 528 Function<Integer, Integer> classifier = i -> i % 3; 529 Function<Integer, Integer> mapper = i -> i * 2; 530 531 exerciseMapCollection(data, 532 groupingBy(classifier, mapping(mapper, toList())), 533 new GroupingByAssertion<>(classifier, HashMap.class, 534 new MappingAssertion<>(mapper, 535 new ToListAssertion<>()))); 536 } 537 538 @Test(groups = { "serialization-hostile" }) 539 public void testFlatMappingClose() { 540 Function<Integer, Integer> classifier = i -> i; 541 AtomicInteger ai = new AtomicInteger(); 542 Function<Integer, Stream<Integer>> flatMapper = i -> Stream.of(i, i).onClose(ai::getAndIncrement); 543 Map<Integer, List<Integer>> m = Stream.of(1, 2).collect(groupingBy(classifier, flatMapping(flatMapper, toList()))); 544 assertEquals(m.size(), ai.get()); 545 } 546 547 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 548 public void testGroupingByWithFlatMapping(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 549 Function<Integer, Integer> classifier = i -> i % 3; 550 Function<Integer, Stream<Integer>> flatMapperByNull = i -> null; 551 Function<Integer, Stream<Integer>> flatMapperBy0 = i -> Stream.empty(); 552 Function<Integer, Stream<Integer>> flatMapperBy2 = i -> Stream.of(i, i); 553 554 exerciseMapCollection(data, 555 groupingBy(classifier, flatMapping(flatMapperByNull, toList())), 556 new GroupingByAssertion<>(classifier, HashMap.class, 557 new FlatMappingAssertion<>(flatMapperBy0, 558 new ToListAssertion<>()))); 559 exerciseMapCollection(data, 560 groupingBy(classifier, flatMapping(flatMapperBy0, toList())), 561 new GroupingByAssertion<>(classifier, HashMap.class, 562 new FlatMappingAssertion<>(flatMapperBy0, 563 new ToListAssertion<>()))); 564 exerciseMapCollection(data, 565 groupingBy(classifier, flatMapping(flatMapperBy2, toList())), 566 new GroupingByAssertion<>(classifier, HashMap.class, 567 new FlatMappingAssertion<>(flatMapperBy2, 568 new ToListAssertion<>()))); 569 } 570 571 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 572 public void testGroupingByWithFiltering(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 573 Function<Integer, Integer> classifier = i -> i % 3; 574 Predicate<Integer> filteringByMod2 = i -> i % 2 == 0; 575 Predicate<Integer> filteringByUnder100 = i -> i % 2 < 100; 576 Predicate<Integer> filteringByTrue = i -> true; 577 Predicate<Integer> filteringByFalse = i -> false; 578 579 exerciseMapCollection(data, 580 groupingBy(classifier, filtering(filteringByMod2, toList())), 581 new GroupingByAssertion<>(classifier, HashMap.class, 582 new FilteringAssertion<>(filteringByMod2, 583 new ToListAssertion<>()))); 584 exerciseMapCollection(data, 585 groupingBy(classifier, filtering(filteringByUnder100, toList())), 586 new GroupingByAssertion<>(classifier, HashMap.class, 587 new FilteringAssertion<>(filteringByUnder100, 588 new ToListAssertion<>()))); 589 exerciseMapCollection(data, 590 groupingBy(classifier, filtering(filteringByTrue, toList())), 591 new GroupingByAssertion<>(classifier, HashMap.class, 592 new FilteringAssertion<>(filteringByTrue, 593 new ToListAssertion<>()))); 594 exerciseMapCollection(data, 595 groupingBy(classifier, filtering(filteringByFalse, toList())), 596 new GroupingByAssertion<>(classifier, HashMap.class, 597 new FilteringAssertion<>(filteringByFalse, 598 new ToListAssertion<>()))); 599 } 600 601 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 602 public void testTwoLevelGroupingBy(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 603 Function<Integer, Integer> classifier = i -> i % 6; 604 Function<Integer, Integer> classifier2 = i -> i % 23; 605 606 // Two-level groupBy 607 exerciseMapCollection(data, 608 groupingBy(classifier, groupingBy(classifier2)), 609 new GroupingByAssertion<>(classifier, HashMap.class, 610 new GroupingByAssertion<>(classifier2, HashMap.class, 611 new ToListAssertion<>()))); 612 // with concurrent as upstream 613 exerciseMapCollection(data, 614 groupingByConcurrent(classifier, groupingBy(classifier2)), 615 new GroupingByAssertion<>(classifier, ConcurrentHashMap.class, 616 new GroupingByAssertion<>(classifier2, HashMap.class, 617 new ToListAssertion<>()))); 618 // with concurrent as downstream 619 exerciseMapCollection(data, 620 groupingBy(classifier, groupingByConcurrent(classifier2)), 621 new GroupingByAssertion<>(classifier, HashMap.class, 622 new GroupingByAssertion<>(classifier2, ConcurrentHashMap.class, 623 new ToListAssertion<>()))); 624 // with concurrent as upstream and downstream 625 exerciseMapCollection(data, 626 groupingByConcurrent(classifier, groupingByConcurrent(classifier2)), 627 new GroupingByAssertion<>(classifier, ConcurrentHashMap.class, 628 new GroupingByAssertion<>(classifier2, ConcurrentHashMap.class, 629 new ToListAssertion<>()))); 630 631 // With explicit constructors 632 exerciseMapCollection(data, 633 groupingBy(classifier, TreeMap::new, groupingBy(classifier2, TreeMap::new, toCollection(HashSet::new))), 634 new GroupingByAssertion<>(classifier, TreeMap.class, 635 new GroupingByAssertion<>(classifier2, TreeMap.class, 636 new ToCollectionAssertion<Integer>(HashSet.class, false)))); 637 // with concurrent as upstream 638 exerciseMapCollection(data, 639 groupingByConcurrent(classifier, ConcurrentSkipListMap::new, groupingBy(classifier2, TreeMap::new, toList())), 640 new GroupingByAssertion<>(classifier, ConcurrentSkipListMap.class, 641 new GroupingByAssertion<>(classifier2, TreeMap.class, 642 new ToListAssertion<>()))); 643 // with concurrent as downstream 644 exerciseMapCollection(data, 645 groupingBy(classifier, TreeMap::new, groupingByConcurrent(classifier2, ConcurrentSkipListMap::new, toList())), 646 new GroupingByAssertion<>(classifier, TreeMap.class, 647 new GroupingByAssertion<>(classifier2, ConcurrentSkipListMap.class, 648 new ToListAssertion<>()))); 649 // with concurrent as upstream and downstream 650 exerciseMapCollection(data, 651 groupingByConcurrent(classifier, ConcurrentSkipListMap::new, groupingByConcurrent(classifier2, ConcurrentSkipListMap::new, toList())), 652 new GroupingByAssertion<>(classifier, ConcurrentSkipListMap.class, 653 new GroupingByAssertion<>(classifier2, ConcurrentSkipListMap.class, 654 new ToListAssertion<>()))); 655 } 656 657 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 658 public void testGroupubgByWithReducing(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 659 Function<Integer, Integer> classifier = i -> i % 3; 660 661 // Single-level simple reduce 662 exerciseMapCollection(data, 663 groupingBy(classifier, reducing(0, Integer::sum)), 664 new GroupingByAssertion<>(classifier, HashMap.class, 665 new ReducingAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum))); 666 // with concurrent 667 exerciseMapCollection(data, 668 groupingByConcurrent(classifier, reducing(0, Integer::sum)), 669 new GroupingByAssertion<>(classifier, ConcurrentHashMap.class, 670 new ReducingAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum))); 671 672 // With explicit constructors 673 exerciseMapCollection(data, 674 groupingBy(classifier, TreeMap::new, reducing(0, Integer::sum)), 675 new GroupingByAssertion<>(classifier, TreeMap.class, 676 new ReducingAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum))); 677 // with concurrent 678 exerciseMapCollection(data, 679 groupingByConcurrent(classifier, ConcurrentSkipListMap::new, reducing(0, Integer::sum)), 680 new GroupingByAssertion<>(classifier, ConcurrentSkipListMap.class, 681 new ReducingAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum))); 682 683 // Single-level map-reduce 684 exerciseMapCollection(data, 685 groupingBy(classifier, reducing(0, mDoubler, Integer::sum)), 686 new GroupingByAssertion<>(classifier, HashMap.class, 687 new ReducingAssertion<>(0, mDoubler, Integer::sum))); 688 // with concurrent 689 exerciseMapCollection(data, 690 groupingByConcurrent(classifier, reducing(0, mDoubler, Integer::sum)), 691 new GroupingByAssertion<>(classifier, ConcurrentHashMap.class, 692 new ReducingAssertion<>(0, mDoubler, Integer::sum))); 693 694 // With explicit constructors 695 exerciseMapCollection(data, 696 groupingBy(classifier, TreeMap::new, reducing(0, mDoubler, Integer::sum)), 697 new GroupingByAssertion<>(classifier, TreeMap.class, 698 new ReducingAssertion<>(0, mDoubler, Integer::sum))); 699 // with concurrent 700 exerciseMapCollection(data, 701 groupingByConcurrent(classifier, ConcurrentSkipListMap::new, reducing(0, mDoubler, Integer::sum)), 702 new GroupingByAssertion<>(classifier, ConcurrentSkipListMap.class, 703 new ReducingAssertion<>(0, mDoubler, Integer::sum))); 704 } 705 706 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 707 public void testSimplePartitioningBy(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 708 Predicate<Integer> classifier = i -> i % 3 == 0; 709 710 // Single-level partition to downstream List 711 exerciseMapCollection(data, 712 partitioningBy(classifier), 713 new PartitioningByAssertion<>(classifier, new ToListAssertion<>())); 714 exerciseMapCollection(data, 715 partitioningBy(classifier, toList()), 716 new PartitioningByAssertion<>(classifier, new ToListAssertion<>())); 717 } 718 719 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 720 public void testTwoLevelPartitioningBy(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 721 Predicate<Integer> classifier = i -> i % 3 == 0; 722 Predicate<Integer> classifier2 = i -> i % 7 == 0; 723 724 // Two level partition 725 exerciseMapCollection(data, 726 partitioningBy(classifier, partitioningBy(classifier2)), 727 new PartitioningByAssertion<>(classifier, 728 new PartitioningByAssertion(classifier2, new ToListAssertion<>()))); 729 730 // Two level partition with reduce 731 exerciseMapCollection(data, 732 partitioningBy(classifier, reducing(0, Integer::sum)), 733 new PartitioningByAssertion<>(classifier, 734 new ReducingAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum))); 735 } 736 737 @Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class) 738 public void testComposeFinisher(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException { 739 List<Integer> asList = exerciseTerminalOps(data, s -> s.collect(toList())); 740 List<Integer> asImmutableList = exerciseTerminalOps(data, s -> s.collect(collectingAndThen(toList(), Collections::unmodifiableList))); 741 assertEquals(asList, asImmutableList); 742 try { 743 asImmutableList.add(0); 744 fail("Expecting immutable result"); 745 } 746 catch (UnsupportedOperationException ignored) { } 747 } 748 749} 750