@Test
public void testHeadTail() {
List<Integer> ints = IntStreamEx.range(1000).boxed().toList();
checkShortCircuitCollector("tail(0)", Arrays.asList(), 0, ints::stream, MoreCollectors.tail(0));
checkCollector("tail(1)", Arrays.asList(999), ints::stream, MoreCollectors.tail(1));
checkCollector("tail(2)", Arrays.asList(998, 999), ints::stream, MoreCollectors.tail(2));
checkCollector("tail(500)", ints.subList(500, 1000), ints::stream, MoreCollectors.tail(500));
checkCollector("tail(999)", ints.subList(1, 1000), ints::stream, MoreCollectors.tail(999));
checkCollector("tail(1000)", ints, ints::stream, MoreCollectors.tail(1000));
checkCollector("tail(MAX)", ints, ints::stream, MoreCollectors.tail(Integer.MAX_VALUE));
checkShortCircuitCollector("head(0)", Arrays.asList(), 0, ints::stream, MoreCollectors.head(0));
checkShortCircuitCollector(
"head(1)", Arrays.asList(0), 1, ints::stream, MoreCollectors.head(1));
checkShortCircuitCollector(
"head(2)", Arrays.asList(0, 1), 2, ints::stream, MoreCollectors.head(2));
checkShortCircuitCollector(
"head(500)", ints.subList(0, 500), 500, ints::stream, MoreCollectors.head(500));
checkShortCircuitCollector(
"head(999)", ints.subList(0, 999), 999, ints::stream, MoreCollectors.head(999));
checkShortCircuitCollector("head(1000)", ints, 1000, ints::stream, MoreCollectors.head(1000));
checkShortCircuitCollector(
"head(MAX)", ints, 1000, ints::stream, MoreCollectors.head(Integer.MAX_VALUE));
checkShortCircuitCollector(
"head(10000)",
IntStreamEx.rangeClosed(1, 10000).boxed().toList(),
10000,
() -> Stream.iterate(1, x -> x + 1),
MoreCollectors.head(10000),
true);
}
@Test
public void testMinIndex() {
List<Integer> ints = IntStreamEx.of(new Random(1), 1000, 5, 47).boxed().toList();
long expectedMin = IntStreamEx.ofIndices(ints).minBy(ints::get).getAsInt();
long expectedMax = IntStreamEx.ofIndices(ints).maxBy(ints::get).getAsInt();
long expectedMinString =
IntStreamEx.ofIndices(ints).minBy(i -> String.valueOf(ints.get(i))).getAsInt();
long expectedMaxString =
IntStreamEx.ofIndices(ints).maxBy(i -> String.valueOf(ints.get(i))).getAsInt();
Comparator<Integer> cmp = Comparator.comparing(String::valueOf);
checkCollector(
"minIndex", OptionalLong.of(expectedMin), ints::stream, MoreCollectors.minIndex());
checkCollector(
"maxIndex", OptionalLong.of(expectedMax), ints::stream, MoreCollectors.maxIndex());
checkCollector(
"minIndex", OptionalLong.of(expectedMinString), ints::stream, MoreCollectors.minIndex(cmp));
checkCollector(
"maxIndex", OptionalLong.of(expectedMaxString), ints::stream, MoreCollectors.maxIndex(cmp));
Supplier<Stream<String>> supplier = () -> ints.stream().map(Object::toString);
checkCollector(
"minIndex", OptionalLong.of(expectedMinString), supplier, MoreCollectors.minIndex());
checkCollector(
"maxIndex", OptionalLong.of(expectedMaxString), supplier, MoreCollectors.maxIndex());
checkCollectorEmpty("minIndex", OptionalLong.empty(), MoreCollectors.<String>minIndex());
checkCollectorEmpty("maxIndex", OptionalLong.empty(), MoreCollectors.<String>maxIndex());
}
@Test
public void testOnlyOne() {
List<Integer> ints = IntStreamEx.rangeClosed(1, 100).boxed().toList();
checkShortCircuitCollector("One", Optional.empty(), 2, ints::stream, MoreCollectors.onlyOne());
checkShortCircuitCollector(
"FilterSeveral",
Optional.empty(),
2,
() -> ints.stream().filter(x -> x % 20 == 0),
MoreCollectors.onlyOne());
checkShortCircuitCollector(
"FilterSeveral2",
Optional.empty(),
40,
ints::stream,
MoreCollectors.filtering(x -> x % 20 == 0, MoreCollectors.onlyOne()));
checkShortCircuitCollector(
"FilterOne",
Optional.of(60),
1,
() -> ints.stream().filter(x -> x % 60 == 0),
MoreCollectors.onlyOne());
checkShortCircuitCollector(
"FilterNone",
Optional.empty(),
0,
() -> ints.stream().filter(x -> x % 110 == 0),
MoreCollectors.onlyOne());
}
@Test
public void testFirstLast() {
Supplier<Stream<Integer>> s = () -> IntStreamEx.range(1000).boxed();
checkShortCircuitCollector("first", Optional.of(0), 1, s, MoreCollectors.first());
checkShortCircuitCollector(
"firstLong",
Optional.of(0),
1,
() -> Stream.of(1).flatMap(x -> IntStream.range(0, 1000000000).boxed()),
MoreCollectors.first(),
true);
checkShortCircuitCollector(
"first",
Optional.of(1),
1,
() -> Stream.iterate(1, x -> x + 1),
MoreCollectors.first(),
true);
assertEquals(
1, (int) StreamEx.iterate(1, x -> x + 1).parallel().collect(MoreCollectors.first()).get());
checkCollector("last", Optional.of(999), s, MoreCollectors.last());
checkCollectorEmpty("first", Optional.empty(), MoreCollectors.first());
checkCollectorEmpty("last", Optional.empty(), MoreCollectors.last());
}
@Test
public void testToEnumSet() {
TimeUnit[] vals = TimeUnit.values();
List<TimeUnit> enumValues =
IntStreamEx.range(100).map(x -> x % vals.length).elements(vals).toList();
checkShortCircuitCollector(
"toEnumSet",
EnumSet.allOf(TimeUnit.class),
vals.length,
enumValues::stream,
MoreCollectors.toEnumSet(TimeUnit.class));
enumValues = IntStreamEx.range(100).map(x -> x % (vals.length - 1)).elements(vals).toList();
EnumSet<TimeUnit> expected = EnumSet.allOf(TimeUnit.class);
expected.remove(vals[vals.length - 1]);
checkShortCircuitCollector(
"toEnumSet", expected, 100, enumValues::stream, MoreCollectors.toEnumSet(TimeUnit.class));
checkCollectorEmpty(
"Empty", EnumSet.noneOf(TimeUnit.class), MoreCollectors.toEnumSet(TimeUnit.class));
}
@Test
public void testAndInt() {
List<Integer> ints = Arrays.asList(0b1100, 0b0110, 0b101110, 0b11110011);
Collector<Integer, ?, OptionalInt> collector = MoreCollectors.andingInt(Integer::intValue);
checkShortCircuitCollector("andInt", OptionalInt.of(0), 4, ints::stream, collector);
checkCollectorEmpty("andIntEmpty", OptionalInt.empty(), collector);
assertEquals(
OptionalInt.of(0),
IntStreamEx.iterate(16384, i -> i + 1).parallel().boxed().collect(collector));
assertEquals(
OptionalInt.of(16384),
IntStreamEx.iterate(16384, i -> i + 1).parallel().limit(16383).boxed().collect(collector));
Collector<Integer, ?, Integer> unwrapped =
MoreCollectors.collectingAndThen(
MoreCollectors.andingInt(Integer::intValue), OptionalInt::getAsInt);
assertTrue(unwrapped.characteristics().contains(Characteristics.UNORDERED));
checkShortCircuitCollector("andIntUnwrapped", 0, 4, ints::stream, unwrapped);
checkShortCircuitCollector(
"andIntUnwrapped", 0, 2, Arrays.asList(0x1, 0x10, 0x100)::stream, unwrapped);
}
@Test
public void testGroupingByWithDomain() {
List<String> data = Arrays.asList("a", "foo", "test", "ququq", "bar", "blahblah");
Collector<String, ?, String> collector =
MoreCollectors.collectingAndThen(
MoreCollectors.groupingBy(
String::length,
IntStreamEx.range(10).boxed().toSet(),
TreeMap::new,
MoreCollectors.first()),
Object::toString);
checkShortCircuitCollector(
"groupingWithDomain",
"{0=Optional.empty, 1=Optional[a], 2=Optional.empty, 3=Optional[foo], 4=Optional[test], 5=Optional[ququq], "
+ "6=Optional.empty, 7=Optional.empty, 8=Optional[blahblah], 9=Optional.empty}",
data.size(),
data::stream,
collector);
Map<String, String> name2sex = new LinkedHashMap<>();
name2sex.put("Mary", "Girl");
name2sex.put("John", "Boy");
name2sex.put("James", "Boy");
name2sex.put("Lucie", "Girl");
name2sex.put("Fred", "Boy");
name2sex.put("Thomas", "Boy");
name2sex.put("Jane", "Girl");
name2sex.put("Ruth", "Girl");
name2sex.put("Melanie", "Girl");
Collector<Entry<String, String>, ?, Map<String, List<String>>> groupingBy =
MoreCollectors.groupingBy(
Entry::getValue,
StreamEx.of("Girl", "Boy").toSet(),
MoreCollectors.mapping(Entry::getKey, MoreCollectors.head(2)));
AtomicInteger counter = new AtomicInteger();
Map<String, List<String>> map =
EntryStream.of(name2sex).peek(c -> counter.incrementAndGet()).collect(groupingBy);
assertEquals(Arrays.asList("Mary", "Lucie"), map.get("Girl"));
assertEquals(Arrays.asList("John", "James"), map.get("Boy"));
assertEquals(4, counter.get());
Collector<Entry<String, String>, ?, Map<String, String>> groupingByJoin =
MoreCollectors.groupingBy(
Entry::getValue,
StreamEx.of("Girl", "Boy").toSet(),
MoreCollectors.mapping(
Entry::getKey, Joining.with(", ").maxChars(16).cutAfterDelimiter()));
counter.set(0);
Map<String, String> mapJoin =
EntryStream.of(name2sex).peek(c -> counter.incrementAndGet()).collect(groupingByJoin);
assertEquals("Mary, Lucie, ...", mapJoin.get("Girl"));
assertEquals("John, James, ...", mapJoin.get("Boy"));
assertEquals(7, counter.get());
}
@Test
public void testPartitioningBy() {
Collector<Integer, ?, Map<Boolean, Optional<Integer>>> by20 =
MoreCollectors.partitioningBy(x -> x % 20 == 0, MoreCollectors.first());
Collector<Integer, ?, Map<Boolean, Optional<Integer>>> by200 =
MoreCollectors.partitioningBy(x -> x % 200 == 0, MoreCollectors.first());
Supplier<Stream<Integer>> supplier = () -> IntStreamEx.range(1, 100).boxed();
checkShortCircuitCollector(
"by20", new BooleanMap<>(Optional.of(20), Optional.of(1)), 20, supplier, by20);
checkShortCircuitCollector(
"by200", new BooleanMap<>(Optional.empty(), Optional.of(1)), 99, supplier, by200);
}
@Test
public void testToBooleanArray() {
List<Integer> input = IntStreamEx.of(new Random(1), 1000, 1, 100).boxed().toList();
boolean[] expected = new boolean[input.size()];
for (int i = 0; i < expected.length; i++) expected[i] = input.get(i) > 50;
for (StreamExSupplier<Integer> supplier : streamEx(input::stream)) {
assertArrayEquals(
supplier.toString(),
expected,
supplier.get().collect(MoreCollectors.toBooleanArray(x -> x > 50)));
}
}
@Test
public void testHeadParallel() {
List<Integer> expected = IntStreamEx.range(0, 2000, 2).boxed().toList();
List<Integer> expectedShort = Arrays.asList(0, 1);
for (int i = 0; i < 1000; i++) {
assertEquals(
"#" + i,
expectedShort,
IntStreamEx.range(1000).boxed().parallel().collect(MoreCollectors.head(2)));
assertEquals(
"#" + i,
expected,
IntStreamEx.range(10000)
.boxed()
.parallel()
.filter(x -> x % 2 == 0)
.collect(MoreCollectors.head(1000)));
}
assertEquals(
expectedShort, StreamEx.iterate(0, x -> x + 1).parallel().collect(MoreCollectors.head(2)));
}
@Test
public void testGreatest() {
List<Integer> ints = IntStreamEx.of(new Random(1), 1000, 1, 1000).boxed().toList();
List<Integer> sorted = StreamEx.of(ints).sorted().toList();
List<Integer> revSorted = StreamEx.of(ints).reverseSorted().toList();
Comparator<Integer> byString = Comparator.comparing(String::valueOf);
checkShortCircuitCollector(
"least(0)", Collections.emptyList(), 0, ints::stream, MoreCollectors.least(0));
checkCollector("least(5)", sorted.subList(0, 5), ints::stream, MoreCollectors.least(5));
checkCollector("least(20)", sorted.subList(0, 20), ints::stream, MoreCollectors.least(20));
checkCollector("least(MAX)", sorted, ints::stream, MoreCollectors.least(Integer.MAX_VALUE));
checkCollector(
"least(byString, 20)",
StreamEx.of(ints).sorted(byString).limit(20).toList(),
ints::stream,
MoreCollectors.least(byString, 20));
checkShortCircuitCollector(
"greatest(0)", Collections.emptyList(), 0, ints::stream, MoreCollectors.greatest(0));
checkCollector(
"greatest(5)", revSorted.subList(0, 5), ints::stream, MoreCollectors.greatest(5));
checkCollector(
"greatest(20)", revSorted.subList(0, 20), ints::stream, MoreCollectors.greatest(20));
checkCollector(
"greatest(MAX)", revSorted, ints::stream, MoreCollectors.greatest(Integer.MAX_VALUE));
checkCollector(
"greatest(byString, 20)",
StreamEx.of(ints).reverseSorted(byString).limit(20).toList(),
ints::stream,
MoreCollectors.greatest(byString, 20));
Supplier<Stream<Integer>> s = () -> IntStreamEx.range(100).boxed();
checkCollector("1", IntStreamEx.range(1).boxed().toList(), s, MoreCollectors.least(1));
checkCollector("2", IntStreamEx.range(2).boxed().toList(), s, MoreCollectors.least(2));
checkCollector("10", IntStreamEx.range(10).boxed().toList(), s, MoreCollectors.least(10));
checkCollector("100", IntStreamEx.range(100).boxed().toList(), s, MoreCollectors.least(100));
checkCollector("200", IntStreamEx.range(100).boxed().toList(), s, MoreCollectors.least(200));
}
@Test
public void testFlatMapping() {
{
Map<Integer, List<Integer>> expected =
IntStreamEx.rangeClosed(1, 100)
.boxed()
.toMap(x -> IntStreamEx.rangeClosed(1, x).boxed().toList());
Collector<Integer, ?, Map<Integer, List<Integer>>> groupingBy =
Collectors.groupingBy(
Function.identity(),
MoreCollectors.flatMapping(
x -> IntStream.rangeClosed(1, x).boxed(), Collectors.toList()));
checkCollector(
"flatMappingSimple", expected, () -> IntStreamEx.rangeClosed(1, 100).boxed(), groupingBy);
}
Function<Entry<String, List<String>>, Stream<String>> valuesStream =
e -> e.getValue() == null ? null : e.getValue().stream();
List<Entry<String, List<String>>> list =
EntryStream.of(
"a", Arrays.asList("bb", "cc", "dd"), "b", Arrays.asList("ee", "ff"), "c", null)
.append("c", Arrays.asList("gg"), "b", null, "a", Arrays.asList("hh"))
.toList();
{
Map<String, List<String>> expected =
EntryStream.of(list.stream())
.flatMapValues(l -> l == null ? null : l.stream())
.grouping();
checkCollector(
"flatMappingCombine",
expected,
list::stream,
Collectors.groupingBy(
Entry::getKey, MoreCollectors.flatMapping(valuesStream, Collectors.toList())));
AtomicInteger openClose = new AtomicInteger();
Collector<Entry<String, List<String>>, ?, Map<String, List<String>>> groupingBy =
Collectors.groupingBy(
Entry::getKey,
MoreCollectors.flatMapping(
valuesStream.andThen(
s -> {
if (s == null) return null;
openClose.incrementAndGet();
return s.onClose(openClose::decrementAndGet);
}),
Collectors.toList()));
checkCollector(
"flatMappingCombineClosed",
expected,
list::stream,
MoreCollectors.collectingAndThen(
groupingBy,
res -> {
assertEquals(0, openClose.get());
return res;
}));
boolean catched = false;
try {
Collector<Entry<String, List<String>>, ?, Map<String, List<String>>> groupingByException =
Collectors.groupingBy(
Entry::getKey,
MoreCollectors.flatMapping(
valuesStream.andThen(
s -> {
if (s == null) return null;
openClose.incrementAndGet();
return s.onClose(openClose::decrementAndGet)
.peek(
e -> {
if (e.equals("gg")) throw new IllegalArgumentException(e);
});
}),
Collectors.toList()));
list.stream()
.collect(
MoreCollectors.collectingAndThen(
groupingByException,
res -> {
assertEquals(0, openClose.get());
return res;
}));
} catch (IllegalArgumentException e1) {
assertEquals("gg", e1.getMessage());
catched = true;
}
assertTrue(catched);
}
{
Map<String, List<String>> expected =
EntryStream.of(
"a", Arrays.asList("bb"), "b", Arrays.asList("ee"), "c", Arrays.asList("gg"))
.toMap();
Collector<Entry<String, List<String>>, ?, List<String>> headOne =
MoreCollectors.flatMapping(valuesStream, MoreCollectors.head(1));
checkCollector(
"flatMappingSubShort",
expected,
list::stream,
Collectors.groupingBy(Entry::getKey, headOne));
checkShortCircuitCollector(
"flatMappingShort",
expected,
4,
list::stream,
MoreCollectors.groupingBy(Entry::getKey, StreamEx.of("a", "b", "c").toSet(), headOne));
AtomicInteger cnt = new AtomicInteger();
Collector<Entry<String, List<String>>, ?, List<String>> headPeek =
MoreCollectors.flatMapping(
valuesStream.andThen(s -> s == null ? null : s.peek(x -> cnt.incrementAndGet())),
MoreCollectors.head(1));
assertEquals(
expected, StreamEx.of(list).collect(Collectors.groupingBy(Entry::getKey, headPeek)));
assertEquals(3, cnt.get());
cnt.set(0);
assertEquals(
expected,
StreamEx.of(list)
.collect(
MoreCollectors.groupingBy(
Entry::getKey, StreamEx.of("a", "b", "c").toSet(), headPeek)));
assertEquals(3, cnt.get());
}
{
Map<String, List<String>> expected =
EntryStream.of(
"a",
Arrays.asList("bb", "cc"),
"b",
Arrays.asList("ee", "ff"),
"c",
Arrays.asList("gg"))
.toMap();
Collector<Entry<String, List<String>>, ?, List<String>> headTwo =
MoreCollectors.flatMapping(valuesStream, MoreCollectors.head(2));
checkCollector(
"flatMappingSubShort",
expected,
list::stream,
Collectors.groupingBy(Entry::getKey, headTwo));
AtomicInteger openClose = new AtomicInteger();
boolean catched = false;
try {
Collector<Entry<String, List<String>>, ?, Map<String, List<String>>> groupingByException =
Collectors.groupingBy(
Entry::getKey,
MoreCollectors.flatMapping(
valuesStream.andThen(
s -> {
if (s == null) return null;
openClose.incrementAndGet();
return s.onClose(openClose::decrementAndGet)
.peek(
e -> {
if (e.equals("gg")) throw new IllegalArgumentException(e);
});
}),
MoreCollectors.head(2)));
list.stream()
.collect(
MoreCollectors.collectingAndThen(
groupingByException,
res -> {
assertEquals(0, openClose.get());
return res;
}));
} catch (IllegalArgumentException e1) {
assertEquals("gg", e1.getMessage());
catched = true;
}
assertTrue(catched);
}
}
@Test
public void testCountingInt() {
checkCollector(
"counting", 1000, () -> IntStreamEx.range(1000).boxed(), MoreCollectors.countingInt());
checkCollectorEmpty("counting", 0, MoreCollectors.countingInt());
}
@Test
public void testMaxAll() {
List<String> input = Arrays.asList("a", "bb", "c", "", "cc", "eee", "bb", "ddd");
checkCollector(
"maxAll",
Arrays.asList("eee", "ddd"),
input::stream,
MoreCollectors.maxAll(Comparator.comparingInt(String::length)));
Collector<String, ?, String> maxAllJoin =
MoreCollectors.maxAll(Comparator.comparingInt(String::length), Collectors.joining(","));
checkCollector("maxAllJoin", "eee,ddd", input::stream, maxAllJoin);
checkCollector(
"minAll",
1L,
input::stream,
MoreCollectors.minAll(Comparator.comparingInt(String::length), Collectors.counting()));
checkCollector(
"minAllEmpty",
Arrays.asList(""),
input::stream,
MoreCollectors.minAll(Comparator.comparingInt(String::length)));
checkCollectorEmpty(
"maxAll",
Collections.emptyList(),
MoreCollectors.maxAll(Comparator.comparingInt(String::length)));
checkCollectorEmpty("maxAllJoin", "", maxAllJoin);
List<Integer> ints = IntStreamEx.of(new Random(1), 10000, 1, 1000).boxed().toList();
List<Integer> expectedMax = getMaxAll(ints, Comparator.naturalOrder());
List<Integer> expectedMin = getMaxAll(ints, Comparator.reverseOrder());
Collector<Integer, ?, SimpleEntry<Integer, Long>> downstream =
MoreCollectors.pairing(
MoreCollectors.first(),
Collectors.counting(),
(opt, cnt) -> new AbstractMap.SimpleEntry<>(opt.get(), cnt));
checkCollector("maxAll", expectedMax, ints::stream, MoreCollectors.maxAll(Integer::compare));
checkCollector("minAll", expectedMin, ints::stream, MoreCollectors.minAll());
checkCollector(
"entry",
new SimpleEntry<>(expectedMax.get(0), (long) expectedMax.size()),
ints::stream,
MoreCollectors.maxAll(downstream));
checkCollector(
"entry",
new SimpleEntry<>(expectedMin.get(0), (long) expectedMin.size()),
ints::stream,
MoreCollectors.minAll(downstream));
Integer a = new Integer(1), b = new Integer(1), c = new Integer(1000), d = new Integer(1000);
ints = IntStreamEx.range(10, 100).boxed().append(a, c).prepend(b, d).toList();
for (StreamExSupplier<Integer> supplier : streamEx(ints::stream)) {
List<Integer> list = supplier.get().collect(MoreCollectors.maxAll());
assertEquals(2, list.size());
assertSame(d, list.get(0));
assertSame(c, list.get(1));
list = supplier.get().collect(MoreCollectors.minAll());
assertEquals(2, list.size());
assertSame(b, list.get(0));
assertSame(a, list.get(1));
}
}