/*
* Copyright 2015, 2016 Tagir Valeev
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package one.util.streamex;
import one.util.streamex.StreamExInternals.BooleanMap;
import org.junit.FixMethodOrder;
import org.junit.Test;
import org.junit.runners.MethodSorters;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.*;
import java.util.AbstractMap.SimpleEntry;
import java.util.Map.Entry;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.*;
import java.util.stream.Collector.Characteristics;
import static java.util.Arrays.asList;
import static one.util.streamex.TestHelpers.*;
import static org.junit.Assert.*;
/**
* @author Tagir Valeev
*/
@FixMethodOrder(MethodSorters.NAME_ASCENDING)
public class MoreCollectorsTest {
static class MyNumber implements Comparable<MyNumber> {
int value;
MyNumber(int value) {
this.value = value;
}
@Override
public int hashCode() {
return value;
}
@Override
public boolean equals(Object obj) {
return obj instanceof MyNumber && ((MyNumber)obj).value == value;
}
@Override
public int compareTo(MyNumber o) {
return Integer.compare(value, o.value);
}
}
@Test(expected = UnsupportedOperationException.class)
public void testInstantiate() throws Throwable {
Constructor<MoreCollectors> constructor = MoreCollectors.class.getDeclaredConstructor();
constructor.setAccessible(true);
try {
constructor.newInstance();
} catch (InvocationTargetException e) {
throw e.getCause();
}
}
@Test
public void testToArray() {
List<String> input = asList("a", "bb", "c", "", "cc", "eee", "bb", "ddd");
streamEx(input::stream, supplier -> {
Map<Integer, String[]> result = supplier.get().groupingBy(String::length, HashMap::new,
MoreCollectors.toArray(String[]::new));
assertArrayEquals(new String[] { "" }, result.get(0));
assertArrayEquals(new String[] { "a", "c" }, result.get(1));
assertArrayEquals(new String[] { "bb", "cc", "bb" }, result.get(2));
assertArrayEquals(new String[] { "eee", "ddd" }, result.get(3));
});
}
@Test
public void testEmpty() {
List<Integer> list = Stream.of(1, 2, 3).collect(MoreCollectors.head(0));
assertTrue(list.isEmpty());
}
@Test
public void testDistinctCount() {
List<String> input = asList("a", "bb", "c", "cc", "eee", "bb", "bc", "ddd");
streamEx(input::stream, supplier -> {
Map<String, Integer> result = supplier.get().groupingBy(s -> s.substring(0, 1), HashMap::new,
MoreCollectors.distinctCount(String::length));
assertEquals(1, (int) result.get("a"));
assertEquals(1, (int) result.get("b"));
assertEquals(2, (int) result.get("c"));
assertEquals(1, (int) result.get("d"));
assertEquals(1, (int) result.get("e"));
});
}
@Test
public void testDistinctBy() {
List<String> input = asList("a", "bb", "c", "cc", "eee", "bb", "bc", "ddd", "ca", "ce", "cf", "ded", "dump");
streamEx(input::stream, supplier -> {
Map<String, List<String>> result = supplier.get().groupingBy(s -> s.substring(0, 1), HashMap::new,
MoreCollectors.distinctBy(String::length));
assertEquals(asList("a"), result.get("a"));
assertEquals(asList("bb"), result.get("b"));
assertEquals(asList("c", "cc"), result.get("c"));
assertEquals(asList("ddd", "dump"), result.get("d"));
assertEquals(asList("eee"), result.get("e"));
});
}
@Test
public void testMaxAll() {
List<String> input = asList("a", "bb", "c", "", "cc", "eee", "bb", "ddd");
checkCollector("maxAll", 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", asList(""), input::stream, MoreCollectors.minAll(Comparator
.comparingInt(String::length)));
checkCollectorEmpty("maxAll", Collections.emptyList(), MoreCollectors.maxAll(Comparator
.comparingInt(String::length)));
checkCollectorEmpty("maxAllJoin", "", maxAllJoin);
withRandom(r -> {
List<Integer> ints = IntStreamEx.of(r, 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));
});
MyNumber a = new MyNumber(1), b = new MyNumber(1), c = new MyNumber(1000), d = new MyNumber(1000);
List<MyNumber> nums = IntStreamEx.range(10, 100).mapToObj(MyNumber::new).append(a, c).prepend(b, d).toList();
streamEx(nums::stream, supplier -> {
List<MyNumber> 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));
});
}
private List<Integer> getMaxAll(List<Integer> ints, Comparator<Integer> c) {
List<Integer> expectedMax = null;
for (Integer i : ints) {
if (expectedMax == null || c.compare(i, expectedMax.get(0)) > 0) {
expectedMax = new ArrayList<>();
expectedMax.add(i);
} else if (i.equals(expectedMax.get(0))) {
expectedMax.add(i);
}
}
return expectedMax;
}
@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 testHeadParallel() {
List<Integer> expected = IntStreamEx.range(0, 2000, 2).boxed().toList();
List<Integer> expectedShort = 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 testHeadTail() {
List<Integer> ints = IntStreamEx.range(1000).boxed().toList();
checkShortCircuitCollector("tail(0)", asList(), 0, ints::stream, MoreCollectors.tail(0));
checkCollector("tail(1)", asList(999), ints::stream, MoreCollectors.tail(1));
checkCollector("tail(2)", 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)", asList(), 0, ints::stream, MoreCollectors.head(0));
checkShortCircuitCollector("head(1)", asList(0), 1, ints::stream, MoreCollectors.head(1));
checkShortCircuitCollector("head(2)", 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);
for (int size : new int[] { 1, 10, 20, 40, 60, 80, 90, 98, 99, 100 }) {
checkShortCircuitCollector("head-unordered-" + size, Collections.nCopies(size, "test"), size,
() -> StreamEx.constant("test", 100), MoreCollectors.head(size));
}
}
@Test
public void testGreatest() {
withRandom(r -> {
List<Integer> ints = IntStreamEx.of(r, 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));
checkCollector("greatest(byString, 30)", StreamEx.of(ints).reverseSorted(byString).limit(30).toList(),
ints::stream, MoreCollectors.greatest(byString, 30));
});
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 testCountingInt() {
checkCollector("counting", 1000, () -> IntStreamEx.range(1000).boxed(), MoreCollectors.countingInt());
checkCollectorEmpty("counting", 0, MoreCollectors.countingInt());
}
@Test
public void testMinIndex() {
withRandom(r -> {
List<Integer> ints = IntStreamEx.of(r, 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 testGroupingByEnum() {
EnumMap<TimeUnit, Long> expected = new EnumMap<>(TimeUnit.class);
EnumSet.allOf(TimeUnit.class).forEach(tu -> expected.put(tu, 0L));
expected.put(TimeUnit.SECONDS, 1L);
expected.put(TimeUnit.DAYS, 2L);
expected.put(TimeUnit.NANOSECONDS, 1L);
checkCollector("groupingByEnum", expected, () -> Stream.of(TimeUnit.SECONDS, TimeUnit.DAYS, TimeUnit.DAYS,
TimeUnit.NANOSECONDS), MoreCollectors.groupingByEnum(TimeUnit.class, Function.identity(), Collectors
.counting()));
}
@Test(expected = IllegalStateException.class)
public void testGroupingByWithDomainException() {
List<Integer> list = asList(1, 2, 20, 3, 31, 4);
Collector<Integer, ?, Map<Integer, List<Integer>>> c = MoreCollectors.groupingBy(i -> i % 10, StreamEx.of(0, 1,
2, 3).toSet(), Collectors.toList());
Map<Integer, List<Integer>> map = list.stream().collect(c);
System.out.println(map);
}
@Test
public void testGroupingByWithDomain() {
List<String> data = 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(asList("Mary", "Lucie"), map.get("Girl"));
assertEquals(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 testToBooleanArray() {
withRandom(r -> {
List<Integer> input = IntStreamEx.of(r, 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;
streamEx(input::stream, supplier -> assertArrayEquals(expected, supplier.get().collect(
MoreCollectors.toBooleanArray(x -> x > 50))));
});
}
@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 testMapping() {
List<String> input = asList("Capital", "lower", "Foo", "bar");
Collector<String, ?, Map<Boolean, Optional<Integer>>> collector = MoreCollectors
.partitioningBy(str -> Character.isUpperCase(str.charAt(0)), MoreCollectors.mapping(String::length,
MoreCollectors.first()));
checkShortCircuitCollector("mapping", new BooleanMap<>(Optional.of(7), Optional.of(5)), 2, input::stream,
collector);
Collector<String, ?, Map<Boolean, Optional<Integer>>> collectorLast = MoreCollectors.partitioningBy(
str -> Character.isUpperCase(str.charAt(0)), MoreCollectors.mapping(String::length, MoreCollectors.last()));
checkCollector("last", new BooleanMap<>(Optional.of(3), Optional.of(3)), input::stream, collectorLast);
input = asList("Abc", "Bac", "Aac", "Abv", "Bbc", "Bgd", "Atc", "Bpv");
Map<Character, List<String>> expected = EntryStream.of('A', asList("Abc", "Aac"), 'B', asList("Bac", "Bbc"))
.toMap();
AtomicInteger cnt = new AtomicInteger();
Collector<String, ?, Map<Character, List<String>>> groupMap = Collectors.groupingBy(s -> s.charAt(0),
MoreCollectors.mapping(x -> {
cnt.incrementAndGet();
return x;
}, MoreCollectors.head(2)));
checkCollector("groupMap", expected, input::stream, groupMap);
cnt.set(0);
assertEquals(expected, input.stream().collect(groupMap));
assertEquals(4, cnt.get());
checkCollector("mapping-toList", asList("a", "b", "c"), asList("a1", "b2", "c3")::stream, MoreCollectors
.mapping(str -> str.substring(0, 1)));
}
@Test
public void testIntersecting() {
for (int i = 0; i < 5; i++) {
List<List<String>> input = asList(asList("aa", "bb", "cc"), asList("cc", "bb", "dd"), asList("ee", "dd"),
asList("aa", "bb", "dd"));
checkShortCircuitCollector("#" + i, Collections.emptySet(), 3, input::stream, MoreCollectors.intersecting());
List<List<Integer>> copies = new ArrayList<>(Collections.nCopies(100, asList(1, 2)));
checkShortCircuitCollector("#" + i, StreamEx.of(1, 2).toSet(), 100, copies::stream, MoreCollectors
.intersecting());
copies.addAll(Collections.nCopies(100, asList(3)));
checkShortCircuitCollector("#" + i, Collections.emptySet(), 101, copies::stream, MoreCollectors
.intersecting());
checkCollectorEmpty("#" + i, Collections.emptySet(), MoreCollectors.intersecting());
}
}
@Test
public void testAndInt() {
List<Integer> ints = 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, asList(0x1, 0x10, 0x100)::stream, unwrapped);
}
@Test
public void testAndLong() {
List<Long> longs = asList(0xFFFFFFFFFFFFFFFFL, 0xFFFFFFFF00000000L, 0xFFFFFFFF0000L);
checkShortCircuitCollector("andLong", OptionalLong.of(0xFFFF00000000L), 3, longs::stream, MoreCollectors
.andingLong(Long::longValue));
longs = asList(1L, 2L, 3L, 4L);
checkShortCircuitCollector("andLong", OptionalLong.of(0), 2, longs::stream, MoreCollectors
.andingLong(Long::longValue));
checkCollectorEmpty("andLongEmpty", OptionalLong.empty(), MoreCollectors.andingLong(Long::longValue));
}
@Test
public void testAndLongFlatMap() {
checkShortCircuitCollector("andLongFlat", OptionalLong.of(0), 2, () -> LongStreamEx.of(0).flatMap(
x -> LongStream.range(1, 100000000)).boxed(), MoreCollectors.andingLong(Long::longValue), true);
}
@Test
public void testFiltering() {
Collector<Integer, ?, Optional<Integer>> firstEven = MoreCollectors.filtering(x -> x % 2 == 0, MoreCollectors
.first());
Collector<Integer, ?, Optional<Integer>> firstOdd = MoreCollectors.filtering(x -> x % 2 != 0, MoreCollectors
.first());
Collector<Integer, ?, Integer> sumOddEven = MoreCollectors.pairing(firstEven, firstOdd, (e, o) -> e.get()
+ o.get());
List<Integer> ints = asList(1, 3, 5, 7, 9, 10, 8, 6, 4, 2, 3, 7, 11);
checkShortCircuitCollector("sumOddEven", 11, 6, ints::stream, sumOddEven);
Collector<Integer, ?, Long> countEven = MoreCollectors.filtering(x -> x % 2 == 0, Collectors.counting());
checkCollector("filtering", 5L, ints::stream, countEven);
checkCollector("filtering-toList", asList(1, 5, 3, 7), asList(1, 2, 4, 5, 4, 3, 0, 7, 8, 10)::stream,
MoreCollectors.filtering(x -> x % 2 == 1));
}
@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 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 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", asList("bb", "cc", "dd"), "b", asList("ee", "ff"),
"c", null).append("c", asList("gg"), "b", null, "a", 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", asList("bb"), "b", asList("ee"), "c", 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", asList("bb", "cc"), "b", asList("ee", "ff"), "c",
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);
}
checkCollector("flatMapping-toList", asList(0, 1, 2, 3, 0, 1, 2, 0, 1, 2, 3, 4), asList(4, 3, 5)::stream,
MoreCollectors.flatMapping(x -> IntStreamEx.range(x).boxed()));
}
@Test(expected = IllegalStateException.class)
public void testFlatMappingExceptional() {
Stream.of(1, 2, 3).collect(MoreCollectors.flatMapping(x -> Stream.of(1, x).onClose(() -> {
if (x == 3)
throw new IllegalStateException();
}), Collectors.toList()));
}
@Test(expected = IllegalStateException.class)
public void testFlatMappingShortCircuitExceptional() {
Stream.of(1, 2, 3).collect(MoreCollectors.flatMapping(x -> Stream.of(1, x).onClose(() -> {
if (x == 3)
throw new IllegalStateException();
}), MoreCollectors.head(10)));
}
@Test
public void testFlatMappingExceptionalSuppressed() {
List<Collector<Integer, ?, List<Integer>>> downstreams = asList(MoreCollectors.head(10), Collectors.toList());
for (Collector<Integer, ?, List<Integer>> downstream : downstreams) {
try {
Stream.of(1, 2, 3).collect(MoreCollectors.flatMapping(x -> Stream.of(1, x).peek(y -> {
throw new IllegalArgumentException();
}).onClose(() -> {
throw new IllegalStateException();
}), downstream));
} catch (Exception e) {
assertTrue(e instanceof IllegalArgumentException);
assertTrue(e.getSuppressed()[0] instanceof IllegalStateException);
continue;
}
fail("No exception");
}
}
@Test
public void testCommonPrefix() {
checkCollectorEmpty("prefix", "", MoreCollectors.commonPrefix());
List<String> input = asList("abcdef", "abcdefg", "abcdfgfg", "abcefgh", "abcdfg");
checkShortCircuitCollector("prefix", "abc", input.size(), input::stream, MoreCollectors.commonPrefix());
List<CharSequence> inputSeq = asList(new StringBuffer("abcdef"), "abcdefg", "abcdfgfg", "abcefgh",
new StringBuilder("abcdfg"));
checkShortCircuitCollector("prefix", "abc", inputSeq.size(), inputSeq::stream, MoreCollectors.commonPrefix());
List<String> input2 = asList("abcdef", "abcdefg", "dabcdfgfg", "abcefgh", "abcdfg");
checkShortCircuitCollector("prefix", "", 3, input2::stream, MoreCollectors.commonPrefix());
List<String> inputHalf = new ArrayList<>();
inputHalf.addAll(Collections.nCopies(1000, "abc"));
inputHalf.addAll(Collections.nCopies(1000, "def"));
checkShortCircuitCollector("prefix", "", 1001, inputHalf::stream, MoreCollectors.commonPrefix());
List<String> inputSurrogate = asList("abc\ud801\udc2f", "abc\ud801\udc2f", "abc\ud801\udc14");
checkShortCircuitCollector("prefix", "abc", inputSurrogate.size(), inputSurrogate::stream, MoreCollectors
.commonPrefix());
List<String> inputSurrogateBad = asList("abc\ud801x", "abc\ud801y", "abc\ud801z");
checkShortCircuitCollector("prefix", "abc\ud801", inputSurrogateBad.size(), inputSurrogateBad::stream,
MoreCollectors.commonPrefix());
List<String> inputSurrogateMix = asList("abc\ud801\udc2f", "abc\ud801x", "abc\ud801\udc14");
checkShortCircuitCollector("prefix", "abc", inputSurrogateMix.size(), inputSurrogateMix::stream, MoreCollectors
.commonPrefix());
}
@Test
public void testCommonSuffix() {
checkCollectorEmpty("suffix", "", MoreCollectors.commonSuffix());
List<String> input = asList("defabc", "degfabc", "dfgfgabc", "efghabc", "dfgabc");
checkShortCircuitCollector("suffix", "abc", input.size(), input::stream, MoreCollectors.commonSuffix());
List<CharSequence> inputSeq = asList(new StringBuffer("degfabc"), "dfgfgabc", new StringBuilder("efghabc"),
"defabc", "dfgabc");
checkShortCircuitCollector("suffix", "abc", inputSeq.size(), inputSeq::stream, MoreCollectors.commonSuffix());
List<String> input2 = asList("defabc", "defgabc", "dabcdfgfg", "efghabc", "dfgabc");
checkShortCircuitCollector("suffix", "", 3, input2::stream, MoreCollectors.commonSuffix());
List<String> inputHalf = new ArrayList<>();
inputHalf.addAll(Collections.nCopies(1000, "abc"));
inputHalf.addAll(Collections.nCopies(1000, "def"));
checkShortCircuitCollector("suffix", "", 1001, inputHalf::stream, MoreCollectors.commonSuffix());
List<String> inputSurrogate = asList("\ud801\udc2fabc", "\ud802\udc2fabc", "\ud803\udc2fabc");
checkShortCircuitCollector("suffix", "abc", inputSurrogate.size(), inputSurrogate::stream, MoreCollectors
.commonSuffix());
List<String> inputSurrogateBad = asList("x\udc2fabc", "y\udc2fabc", "z\udc2fabc");
checkShortCircuitCollector("suffix", "\udc2fabc", inputSurrogateBad.size(), inputSurrogateBad::stream,
MoreCollectors.commonSuffix());
List<String> inputSurrogateMix = asList("\ud801\udc2fabc", "x\udc2fabc", "\ud801\udc14abc");
checkShortCircuitCollector("suffix", "abc", inputSurrogateMix.size(), inputSurrogateMix::stream, MoreCollectors
.commonSuffix());
}
@Test
public void testDominators() {
List<String> input = asList("a/", "a/b/c/", "b/c/", "b/d/", "c/a/", "d/a/b/", "c/a/b/", "c/b/", "b/c/d/");
List<String> expected = asList("a/", "b/c/", "b/d/", "c/a/", "c/b/", "d/a/b/");
checkCollector("dominators", expected, () -> input.stream().sorted(), MoreCollectors.dominators((a, b) -> b
.startsWith(a)));
withRandom(r -> {
List<String> longInput = StreamEx.generate(
() -> IntStreamEx.of(r, r.nextInt(10) + 3, 'a', 'z').mapToObj(ch -> (char) ch).joining("/", "", "/"))
.limit(1000).toList();
List<String> tmp = StreamEx.of(longInput).sorted().toList();
List<String> result = new ArrayList<>();
String curr, last;
curr = last = null;
for (String next : tmp) {
String oldLast = last;
last = curr;
curr = next;
if (last != null && curr.startsWith(last)) {
curr = last;
last = oldLast;
} else
result.add(curr);
}
checkCollector("dominatorsLong", result, () -> longInput.stream().sorted(), MoreCollectors
.dominators((a, b) -> b.startsWith(a)));
});
}
@Test
public void testIncreasingDominators() {
int[] input = { 1, 3, 4, 2, 1, 7, 5, 3, 4, 0, 4, 6, 7, 10, 4, 3, 2, 1 };
List<Integer> result = asList(1, 3, 4, 7, 10);
checkCollector("increasing", result, () -> IntStreamEx.of(input).boxed(), MoreCollectors
.dominators((a, b) -> a >= b));
withRandom(r -> {
int[] longInput = r.ints(10000, 0, 1000000).toArray();
List<Integer> longResult = new ArrayList<>();
int curMax = -1;
for (int val : longInput) {
if (val > curMax) {
curMax = val;
longResult.add(curMax);
}
}
checkCollector("increasingLong", longResult, () -> IntStreamEx.of(longInput).boxed(), MoreCollectors
.dominators((a, b) -> a >= b));
});
}
@Test
public void testMinMax() {
List<String> input = asList("abc", "a", "asdf", "gdasa", "gffsd", "sfgs", "b", "c", "dsgs");
checkCollector("minMax", Optional.of("agdasa"), input::stream, MoreCollectors.minMax(Comparator
.comparingInt(String::length), String::concat));
Collector<String, ?, Optional<Object>> collector = MoreCollectors.minMax(Comparator.naturalOrder(),
(min, max) -> {
throw new IllegalStateException("Should not be called");
});
checkCollectorEmpty("minMax", Optional.empty(), collector);
}
@Test
public void testIfAllMatch() {
Supplier<Stream<Integer>> five = () -> IntStreamEx.range(5).boxed();
checkShortCircuitCollector("ifAllMatch: all match", Optional.of(asList(0, 1, 2, 3, 4)), 5, five,
MoreCollectors.ifAllMatch(i -> true, Collectors.toList()));
Supplier<Stream<Integer>> ints = () -> IntStreamEx.ints().boxed();
checkShortCircuitCollector("ifAllMatch: shirtCircuit downstream", Optional.of(asList(0, 1, 2)), 3, ints,
MoreCollectors.ifAllMatch(i -> true, MoreCollectors.head(3)), true);
checkShortCircuitCollector("ifAllMatch: some match", Optional.empty(), 11, ints,
MoreCollectors.ifAllMatch(i -> i < 10, Collectors.toList()), true);
checkShortCircuitCollector("ifAllMatch: empty stream", Optional.of(Collections.emptyList()), 0, Stream::empty,
MoreCollectors.ifAllMatch(i -> true, Collectors.toList()));
}
}