binary-joe
106 lines
3.3 KiB
Java
106 lines
3.3 KiB
Java
package com.baeldung.java8;
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import com.baeldung.java_8_features.Detail;
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import org.junit.Before;
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import org.junit.Test;
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import java.nio.file.Path;
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import java.nio.file.Paths;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.List;
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import java.util.stream.Collectors;
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import java.util.stream.Stream;
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import static org.junit.Assert.*;
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public class Java8StreamsUnitTest {
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private List<String> list;
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@Before
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public void init() {
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list = new ArrayList<>();
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list.add("One");
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list.add("OneAndOnly");
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list.add("Derek");
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list.add("Change");
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list.add("factory");
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list.add("justBefore");
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list.add("Italy");
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list.add("Italy");
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list.add("Thursday");
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list.add("");
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list.add("");
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}
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@Test
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public void checkStreamCount_whenCreating_givenDifferentSources() {
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String[] arr = new String[] { "a", "b", "c" };
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Stream<String> streamArr = Arrays.stream(arr);
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assertEquals(streamArr.count(), 3);
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Stream<String> streamOf = Stream.of("a", "b", "c");
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assertEquals(streamOf.count(), 3);
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long count = list.stream().distinct().count();
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assertEquals(count, 9);
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}
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@Test
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public void checkStreamCount_whenOperationFilter_thanCorrect() {
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Stream<String> streamFilter = list.stream().filter(element -> element.isEmpty());
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assertEquals(streamFilter.count(), 2);
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}
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@Test
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public void checkStreamCount_whenOperationMap_thanCorrect() {
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List<String> uris = new ArrayList<>();
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uris.add("C:\\My.txt");
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Stream<Path> streamMap = uris.stream().map(uri -> Paths.get(uri));
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assertEquals(streamMap.count(), 1);
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List<Detail> details = new ArrayList<>();
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details.add(new Detail());
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details.add(new Detail());
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Stream<String> streamFlatMap = details.stream().flatMap(detail -> detail.getParts().stream());
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assertEquals(streamFlatMap.count(), 4);
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}
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@Test
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public void checkStreamCount_whenOperationMatch_thenCorrect() {
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boolean isValid = list.stream().anyMatch(element -> element.contains("h"));
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boolean isValidOne = list.stream().allMatch(element -> element.contains("h"));
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boolean isValidTwo = list.stream().noneMatch(element -> element.contains("h"));
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assertTrue(isValid);
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assertFalse(isValidOne);
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assertFalse(isValidTwo);
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}
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@Test
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public void checkStreamReducedValue_whenOperationReduce_thenCorrect() {
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List<Integer> integers = new ArrayList<>();
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integers.add(1);
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integers.add(1);
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integers.add(1);
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Integer reduced = integers.stream().reduce(23, (a, b) -> a + b);
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assertTrue(reduced == 26);
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}
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@Test
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public void checkStreamContains_whenOperationCollect_thenCorrect() {
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List<String> resultList = list.stream().map(element -> element.toUpperCase()).collect(Collectors.toList());
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assertEquals(resultList.size(), list.size());
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assertTrue(resultList.contains(""));
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}
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@Test
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public void checkParallelStream_whenDoWork() {
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list.parallelStream().forEach(element -> doWork(element));
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}
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private void doWork(String string) {
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assertTrue(true); // just imitate an amount of work
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}
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}
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