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Java example source code file (TabulatorsTest.java)
This example Java source code file (TabulatorsTest.java) is included in the alvinalexander.com
"Java Source Code
Warehouse" project. The intent of this project is to help you "Learn
Java by Example" TM.
Learn more about this Java project at its project page.
The TabulatorsTest.java Java example source code
/*
* Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package org.openjdk.tests.java.util.stream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.StringJoiner;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.function.Supplier;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import java.util.stream.LambdaTestHelpers;
import java.util.stream.OpTestCase;
import java.util.stream.Stream;
import java.util.stream.StreamOpFlagTestHelper;
import java.util.stream.StreamTestDataProvider;
import java.util.stream.TestData;
import org.testng.annotations.Test;
import static java.util.stream.Collectors.collectingAndThen;
import static java.util.stream.Collectors.groupingBy;
import static java.util.stream.Collectors.groupingByConcurrent;
import static java.util.stream.Collectors.partitioningBy;
import static java.util.stream.Collectors.reducing;
import static java.util.stream.Collectors.toCollection;
import static java.util.stream.Collectors.toConcurrentMap;
import static java.util.stream.Collectors.toList;
import static java.util.stream.Collectors.toMap;
import static java.util.stream.Collectors.toSet;
import static java.util.stream.LambdaTestHelpers.assertContents;
import static java.util.stream.LambdaTestHelpers.assertContentsUnordered;
import static java.util.stream.LambdaTestHelpers.mDoubler;
/**
* TabulatorsTest
*
* @author Brian Goetz
*/
@SuppressWarnings({"rawtypes", "unchecked"})
public class TabulatorsTest extends OpTestCase {
private static abstract class TabulationAssertion<T, U> {
abstract void assertValue(U value,
Supplier<Stream source,
boolean ordered) throws ReflectiveOperationException;
}
@SuppressWarnings({"rawtypes", "unchecked"})
static class GroupedMapAssertion<T, K, V, M extends Map extends TabulationAssertion {
private final Class<? extends Map> clazz;
private final Function<T, K> classifier;
private final TabulationAssertion<T,V> downstream;
protected GroupedMapAssertion(Function<T, K> classifier,
Class<? extends Map> clazz,
TabulationAssertion<T, V> downstream) {
this.clazz = clazz;
this.classifier = classifier;
this.downstream = downstream;
}
void assertValue(M map,
Supplier<Stream source,
boolean ordered) throws ReflectiveOperationException {
if (!clazz.isAssignableFrom(map.getClass()))
fail(String.format("Class mismatch in GroupedMapAssertion: %s, %s", clazz, map.getClass()));
assertContentsUnordered(map.keySet(), source.get().map(classifier).collect(toSet()));
for (Map.Entry<K, ? extends V> entry : map.entrySet()) {
K key = entry.getKey();
downstream.assertValue(entry.getValue(),
() -> source.get().filter(e -> classifier.apply(e).equals(key)),
ordered);
}
}
}
static class ToMapAssertion<T, K, V, M extends Map extends TabulationAssertion {
private final Class<? extends Map> clazz;
private final Function<T, K> keyFn;
private final Function<T, V> valueFn;
private final BinaryOperator<V> mergeFn;
ToMapAssertion(Function<T, K> keyFn,
Function<T, V> valueFn,
BinaryOperator<V> mergeFn,
Class<? extends Map> clazz) {
this.clazz = clazz;
this.keyFn = keyFn;
this.valueFn = valueFn;
this.mergeFn = mergeFn;
}
@Override
void assertValue(M map, Supplier<Stream source, boolean ordered) throws ReflectiveOperationException {
Set<K> uniqueKeys = source.get().map(keyFn).collect(toSet());
assertTrue(clazz.isAssignableFrom(map.getClass()));
assertEquals(uniqueKeys, map.keySet());
source.get().forEach(t -> {
K key = keyFn.apply(t);
V v = source.get()
.filter(e -> key.equals(keyFn.apply(e)))
.map(valueFn)
.reduce(mergeFn)
.get();
assertEquals(map.get(key), v);
});
}
}
static class PartitionAssertion<T, D> extends TabulationAssertion> {
private final Predicate<T> predicate;
private final TabulationAssertion<T,D> downstream;
protected PartitionAssertion(Predicate<T> predicate,
TabulationAssertion<T, D> downstream) {
this.predicate = predicate;
this.downstream = downstream;
}
void assertValue(Map<Boolean, D> map,
Supplier<Stream source,
boolean ordered) throws ReflectiveOperationException {
if (!Map.class.isAssignableFrom(map.getClass()))
fail(String.format("Class mismatch in PartitionAssertion: %s", map.getClass()));
assertEquals(2, map.size());
downstream.assertValue(map.get(true), () -> source.get().filter(predicate), ordered);
downstream.assertValue(map.get(false), () -> source.get().filter(predicate.negate()), ordered);
}
}
@SuppressWarnings({"rawtypes", "unchecked"})
static class ListAssertion<T> extends TabulationAssertion> {
@Override
void assertValue(List<T> value, Supplier> source, boolean ordered)
throws ReflectiveOperationException {
if (!List.class.isAssignableFrom(value.getClass()))
fail(String.format("Class mismatch in ListAssertion: %s", value.getClass()));
Stream<T> stream = source.get();
List<T> result = new ArrayList<>();
for (Iterator<T> it = stream.iterator(); it.hasNext(); ) // avoid capturing result::add
result.add(it.next());
if (StreamOpFlagTestHelper.isStreamOrdered(stream) && ordered)
assertContents(value, result);
else
assertContentsUnordered(value, result);
}
}
@SuppressWarnings({"rawtypes", "unchecked"})
static class CollectionAssertion<T> extends TabulationAssertion> {
private final Class<? extends Collection> clazz;
private final boolean targetOrdered;
protected CollectionAssertion(Class<? extends Collection> clazz, boolean targetOrdered) {
this.clazz = clazz;
this.targetOrdered = targetOrdered;
}
@Override
void assertValue(Collection<T> value, Supplier> source, boolean ordered)
throws ReflectiveOperationException {
if (!clazz.isAssignableFrom(value.getClass()))
fail(String.format("Class mismatch in CollectionAssertion: %s, %s", clazz, value.getClass()));
Stream<T> stream = source.get();
Collection<T> result = clazz.newInstance();
for (Iterator<T> it = stream.iterator(); it.hasNext(); ) // avoid capturing result::add
result.add(it.next());
if (StreamOpFlagTestHelper.isStreamOrdered(stream) && targetOrdered && ordered)
assertContents(value, result);
else
assertContentsUnordered(value, result);
}
}
static class ReduceAssertion<T, U> extends TabulationAssertion {
private final U identity;
private final Function<T, U> mapper;
private final BinaryOperator<U> reducer;
ReduceAssertion(U identity, Function<T, U> mapper, BinaryOperator reducer) {
this.identity = identity;
this.mapper = mapper;
this.reducer = reducer;
}
@Override
void assertValue(U value, Supplier<Stream source, boolean ordered)
throws ReflectiveOperationException {
Optional<U> reduced = source.get().map(mapper).reduce(reducer);
if (value == null)
assertTrue(!reduced.isPresent());
else if (!reduced.isPresent()) {
assertEquals(value, identity);
}
else {
assertEquals(value, reduced.get());
}
}
}
private <T> ResultAsserter mapTabulationAsserter(boolean ordered) {
return (act, exp, ord, par) -> {
if (par && (!ordered || !ord)) {
TabulatorsTest.nestedMapEqualityAssertion(act, exp);
}
else {
LambdaTestHelpers.assertContentsEqual(act, exp);
}
};
}
private<T, M extends Map>
void exerciseMapTabulation(TestData<T, Stream data,
Collector<T, ?, ? extends M> collector,
TabulationAssertion<T, M> assertion)
throws ReflectiveOperationException {
boolean ordered = !collector.characteristics().contains(Collector.Characteristics.UNORDERED);
M m = withData(data)
.terminal(s -> s.collect(collector))
.resultAsserter(mapTabulationAsserter(ordered))
.exercise();
assertion.assertValue(m, () -> data.stream(), ordered);
m = withData(data)
.terminal(s -> s.unordered().collect(collector))
.resultAsserter(mapTabulationAsserter(ordered))
.exercise();
assertion.assertValue(m, () -> data.stream(), false);
}
private static void nestedMapEqualityAssertion(Object o1, Object o2) {
if (o1 instanceof Map) {
Map m1 = (Map) o1;
Map m2 = (Map) o2;
assertContentsUnordered(m1.keySet(), m2.keySet());
for (Object k : m1.keySet())
nestedMapEqualityAssertion(m1.get(k), m2.get(k));
}
else if (o1 instanceof Collection) {
assertContentsUnordered(((Collection) o1), ((Collection) o2));
}
else
assertEquals(o1, o2);
}
private<T, R> void assertCollect(TestData.OfRef data,
Collector<T, ?, R> collector,
Function<Stream streamReduction) {
R check = streamReduction.apply(data.stream());
withData(data).terminal(s -> s.collect(collector)).expectedResult(check).exercise();
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testReduce(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
assertCollect(data, Collectors.reducing(0, Integer::sum),
s -> s.reduce(0, Integer::sum));
assertCollect(data, Collectors.reducing(Integer.MAX_VALUE, Integer::min),
s -> s.min(Integer::compare).orElse(Integer.MAX_VALUE));
assertCollect(data, Collectors.reducing(Integer.MIN_VALUE, Integer::max),
s -> s.max(Integer::compare).orElse(Integer.MIN_VALUE));
assertCollect(data, Collectors.reducing(Integer::sum),
s -> s.reduce(Integer::sum));
assertCollect(data, Collectors.minBy(Comparator.naturalOrder()),
s -> s.min(Integer::compare));
assertCollect(data, Collectors.maxBy(Comparator.naturalOrder()),
s -> s.max(Integer::compare));
assertCollect(data, Collectors.reducing(0, x -> x*2, Integer::sum),
s -> s.map(x -> x*2).reduce(0, Integer::sum));
assertCollect(data, Collectors.summingLong(x -> x * 2L),
s -> s.map(x -> x*2L).reduce(0L, Long::sum));
assertCollect(data, Collectors.summingInt(x -> x * 2),
s -> s.map(x -> x*2).reduce(0, Integer::sum));
assertCollect(data, Collectors.summingDouble(x -> x * 2.0d),
s -> s.map(x -> x * 2.0d).reduce(0.0d, Double::sum));
assertCollect(data, Collectors.averagingInt(x -> x * 2),
s -> s.mapToInt(x -> x * 2).average().orElse(0));
assertCollect(data, Collectors.averagingLong(x -> x * 2),
s -> s.mapToLong(x -> x * 2).average().orElse(0));
assertCollect(data, Collectors.averagingDouble(x -> x * 2),
s -> s.mapToDouble(x -> x * 2).average().orElse(0));
// Test explicit Collector.of
Collector<Integer, long[], Double> avg2xint = Collector.of(() -> new long[2],
(a, b) -> {
a[0] += b * 2;
a[1]++;
},
(a, b) -> {
a[0] += b[0];
a[1] += b[1];
return a;
},
a -> a[1] == 0 ? 0.0d : (double) a[0] / a[1]);
assertCollect(data, avg2xint,
s -> s.mapToInt(x -> x * 2).average().orElse(0));
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testJoin(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
withData(data)
.terminal(s -> s.map(Object::toString).collect(Collectors.joining()))
.expectedResult(join(data, ""))
.exercise();
Collector<String, StringBuilder, String> likeJoining = Collector.of(StringBuilder::new, StringBuilder::append, (sb1, sb2) -> sb1.append(sb2.toString()), StringBuilder::toString);
withData(data)
.terminal(s -> s.map(Object::toString).collect(likeJoining))
.expectedResult(join(data, ""))
.exercise();
withData(data)
.terminal(s -> s.map(Object::toString).collect(Collectors.joining(",")))
.expectedResult(join(data, ","))
.exercise();
withData(data)
.terminal(s -> s.map(Object::toString).collect(Collectors.joining(",", "[", "]")))
.expectedResult("[" + join(data, ",") + "]")
.exercise();
withData(data)
.terminal(s -> s.map(Object::toString)
.collect(StringBuilder::new, StringBuilder::append, StringBuilder::append)
.toString())
.expectedResult(join(data, ""))
.exercise();
withData(data)
.terminal(s -> s.map(Object::toString)
.collect(() -> new StringJoiner(","),
(sj, cs) -> sj.add(cs),
(j1, j2) -> j1.merge(j2))
.toString())
.expectedResult(join(data, ","))
.exercise();
withData(data)
.terminal(s -> s.map(Object::toString)
.collect(() -> new StringJoiner(",", "[", "]"),
(sj, cs) -> sj.add(cs),
(j1, j2) -> j1.merge(j2))
.toString())
.expectedResult("[" + join(data, ",") + "]")
.exercise();
}
private<T> String join(TestData.OfRef data, String delim) {
StringBuilder sb = new StringBuilder();
boolean first = true;
for (T i : data) {
if (!first)
sb.append(delim);
sb.append(i.toString());
first = false;
}
return sb.toString();
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testSimpleToMap(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
Function<Integer, Integer> keyFn = i -> i * 2;
Function<Integer, Integer> valueFn = i -> i * 4;
List<Integer> dataAsList = Arrays.asList(data.stream().toArray(Integer[]::new));
Set<Integer> dataAsSet = new HashSet<>(dataAsList);
BinaryOperator<Integer> sum = Integer::sum;
for (BinaryOperator<Integer> op : Arrays.asList((u, v) -> u,
(u, v) -> v,
sum)) {
try {
exerciseMapTabulation(data, toMap(keyFn, valueFn),
new ToMapAssertion<>(keyFn, valueFn, op, HashMap.class));
if (dataAsList.size() != dataAsSet.size())
fail("Expected ISE on input with duplicates");
}
catch (IllegalStateException e) {
if (dataAsList.size() == dataAsSet.size())
fail("Expected no ISE on input without duplicates");
}
exerciseMapTabulation(data, toMap(keyFn, valueFn, op),
new ToMapAssertion<>(keyFn, valueFn, op, HashMap.class));
exerciseMapTabulation(data, toMap(keyFn, valueFn, op, TreeMap::new),
new ToMapAssertion<>(keyFn, valueFn, op, TreeMap.class));
}
// For concurrent maps, only use commutative merge functions
try {
exerciseMapTabulation(data, toConcurrentMap(keyFn, valueFn),
new ToMapAssertion<>(keyFn, valueFn, sum, ConcurrentHashMap.class));
if (dataAsList.size() != dataAsSet.size())
fail("Expected ISE on input with duplicates");
}
catch (IllegalStateException e) {
if (dataAsList.size() == dataAsSet.size())
fail("Expected no ISE on input without duplicates");
}
exerciseMapTabulation(data, toConcurrentMap(keyFn, valueFn, sum),
new ToMapAssertion<>(keyFn, valueFn, sum, ConcurrentHashMap.class));
exerciseMapTabulation(data, toConcurrentMap(keyFn, valueFn, sum, ConcurrentSkipListMap::new),
new ToMapAssertion<>(keyFn, valueFn, sum, ConcurrentSkipListMap.class));
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testSimpleGroupBy(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
Function<Integer, Integer> classifier = i -> i % 3;
// Single-level groupBy
exerciseMapTabulation(data, groupingBy(classifier),
new GroupedMapAssertion<>(classifier, HashMap.class,
new ListAssertion<>()));
exerciseMapTabulation(data, groupingByConcurrent(classifier),
new GroupedMapAssertion<>(classifier, ConcurrentHashMap.class,
new ListAssertion<>()));
// With explicit constructors
exerciseMapTabulation(data,
groupingBy(classifier, TreeMap::new, toCollection(HashSet::new)),
new GroupedMapAssertion<>(classifier, TreeMap.class,
new CollectionAssertion<Integer>(HashSet.class, false)));
exerciseMapTabulation(data,
groupingByConcurrent(classifier, ConcurrentSkipListMap::new,
toCollection(HashSet::new)),
new GroupedMapAssertion<>(classifier, ConcurrentSkipListMap.class,
new CollectionAssertion<Integer>(HashSet.class, false)));
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testTwoLevelGroupBy(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
Function<Integer, Integer> classifier = i -> i % 6;
Function<Integer, Integer> classifier2 = i -> i % 23;
// Two-level groupBy
exerciseMapTabulation(data,
groupingBy(classifier, groupingBy(classifier2)),
new GroupedMapAssertion<>(classifier, HashMap.class,
new GroupedMapAssertion<>(classifier2, HashMap.class,
new ListAssertion<>())));
// with concurrent as upstream
exerciseMapTabulation(data,
groupingByConcurrent(classifier, groupingBy(classifier2)),
new GroupedMapAssertion<>(classifier, ConcurrentHashMap.class,
new GroupedMapAssertion<>(classifier2, HashMap.class,
new ListAssertion<>())));
// with concurrent as downstream
exerciseMapTabulation(data,
groupingBy(classifier, groupingByConcurrent(classifier2)),
new GroupedMapAssertion<>(classifier, HashMap.class,
new GroupedMapAssertion<>(classifier2, ConcurrentHashMap.class,
new ListAssertion<>())));
// with concurrent as upstream and downstream
exerciseMapTabulation(data,
groupingByConcurrent(classifier, groupingByConcurrent(classifier2)),
new GroupedMapAssertion<>(classifier, ConcurrentHashMap.class,
new GroupedMapAssertion<>(classifier2, ConcurrentHashMap.class,
new ListAssertion<>())));
// With explicit constructors
exerciseMapTabulation(data,
groupingBy(classifier, TreeMap::new, groupingBy(classifier2, TreeMap::new, toCollection(HashSet::new))),
new GroupedMapAssertion<>(classifier, TreeMap.class,
new GroupedMapAssertion<>(classifier2, TreeMap.class,
new CollectionAssertion<Integer>(HashSet.class, false))));
// with concurrent as upstream
exerciseMapTabulation(data,
groupingByConcurrent(classifier, ConcurrentSkipListMap::new, groupingBy(classifier2, TreeMap::new, toList())),
new GroupedMapAssertion<>(classifier, ConcurrentSkipListMap.class,
new GroupedMapAssertion<>(classifier2, TreeMap.class,
new ListAssertion<>())));
// with concurrent as downstream
exerciseMapTabulation(data,
groupingBy(classifier, TreeMap::new, groupingByConcurrent(classifier2, ConcurrentSkipListMap::new, toList())),
new GroupedMapAssertion<>(classifier, TreeMap.class,
new GroupedMapAssertion<>(classifier2, ConcurrentSkipListMap.class,
new ListAssertion<>())));
// with concurrent as upstream and downstream
exerciseMapTabulation(data,
groupingByConcurrent(classifier, ConcurrentSkipListMap::new, groupingByConcurrent(classifier2, ConcurrentSkipListMap::new, toList())),
new GroupedMapAssertion<>(classifier, ConcurrentSkipListMap.class,
new GroupedMapAssertion<>(classifier2, ConcurrentSkipListMap.class,
new ListAssertion<>())));
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testGroupedReduce(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
Function<Integer, Integer> classifier = i -> i % 3;
// Single-level simple reduce
exerciseMapTabulation(data,
groupingBy(classifier, reducing(0, Integer::sum)),
new GroupedMapAssertion<>(classifier, HashMap.class,
new ReduceAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum)));
// with concurrent
exerciseMapTabulation(data,
groupingByConcurrent(classifier, reducing(0, Integer::sum)),
new GroupedMapAssertion<>(classifier, ConcurrentHashMap.class,
new ReduceAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum)));
// With explicit constructors
exerciseMapTabulation(data,
groupingBy(classifier, TreeMap::new, reducing(0, Integer::sum)),
new GroupedMapAssertion<>(classifier, TreeMap.class,
new ReduceAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum)));
// with concurrent
exerciseMapTabulation(data,
groupingByConcurrent(classifier, ConcurrentSkipListMap::new, reducing(0, Integer::sum)),
new GroupedMapAssertion<>(classifier, ConcurrentSkipListMap.class,
new ReduceAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum)));
// Single-level map-reduce
exerciseMapTabulation(data,
groupingBy(classifier, reducing(0, mDoubler, Integer::sum)),
new GroupedMapAssertion<>(classifier, HashMap.class,
new ReduceAssertion<>(0, mDoubler, Integer::sum)));
// with concurrent
exerciseMapTabulation(data,
groupingByConcurrent(classifier, reducing(0, mDoubler, Integer::sum)),
new GroupedMapAssertion<>(classifier, ConcurrentHashMap.class,
new ReduceAssertion<>(0, mDoubler, Integer::sum)));
// With explicit constructors
exerciseMapTabulation(data,
groupingBy(classifier, TreeMap::new, reducing(0, mDoubler, Integer::sum)),
new GroupedMapAssertion<>(classifier, TreeMap.class,
new ReduceAssertion<>(0, mDoubler, Integer::sum)));
// with concurrent
exerciseMapTabulation(data,
groupingByConcurrent(classifier, ConcurrentSkipListMap::new, reducing(0, mDoubler, Integer::sum)),
new GroupedMapAssertion<>(classifier, ConcurrentSkipListMap.class,
new ReduceAssertion<>(0, mDoubler, Integer::sum)));
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testSimplePartition(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
Predicate<Integer> classifier = i -> i % 3 == 0;
// Single-level partition to downstream List
exerciseMapTabulation(data,
partitioningBy(classifier),
new PartitionAssertion<>(classifier, new ListAssertion<>()));
exerciseMapTabulation(data,
partitioningBy(classifier, toList()),
new PartitionAssertion<>(classifier, new ListAssertion<>()));
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testTwoLevelPartition(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
Predicate<Integer> classifier = i -> i % 3 == 0;
Predicate<Integer> classifier2 = i -> i % 7 == 0;
// Two level partition
exerciseMapTabulation(data,
partitioningBy(classifier, partitioningBy(classifier2)),
new PartitionAssertion<>(classifier,
new PartitionAssertion(classifier2, new ListAssertion<>())));
// Two level partition with reduce
exerciseMapTabulation(data,
partitioningBy(classifier, reducing(0, Integer::sum)),
new PartitionAssertion<>(classifier,
new ReduceAssertion<>(0, LambdaTestHelpers.identity(), Integer::sum)));
}
@Test(dataProvider = "StreamTestData<Integer>", dataProviderClass = StreamTestDataProvider.class)
public void testComposeFinisher(String name, TestData.OfRef<Integer> data) throws ReflectiveOperationException {
List<Integer> asList = exerciseTerminalOps(data, s -> s.collect(toList()));
List<Integer> asImmutableList = exerciseTerminalOps(data, s -> s.collect(collectingAndThen(toList(), Collections::unmodifiableList)));
assertEquals(asList, asImmutableList);
try {
asImmutableList.add(0);
fail("Expecting immutable result");
}
catch (UnsupportedOperationException ignored) { }
}
}
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