66 lines
2.0 KiB
Java
66 lines
2.0 KiB
Java
package com.baeldung.stream;
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import static java.util.stream.Collectors.collectingAndThen;
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import static java.util.stream.Collectors.toList;
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import static java.util.stream.Collectors.toSet;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.LinkedList;
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import java.util.List;
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import java.util.stream.IntStream;
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import org.junit.Test;
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import com.baeldung.stream.mycollectors.MyImmutableListCollector;
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import com.google.common.collect.ImmutableList;
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public class StreamToImmutableUnitTest {
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@Test
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public void whenUsingCollectingToImmutableSet_thenSuccess() {
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List<String> givenList = Arrays.asList("a", "b", "c");
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List<String> result = givenList.stream()
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.collect(collectingAndThen(toSet(), ImmutableList::copyOf));
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System.out.println(result.getClass());
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}
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@Test
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public void whenUsingCollectingToUnmodifiableList_thenSuccess() {
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List<String> givenList = new ArrayList<>(Arrays.asList("a", "b", "c"));
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List<String> result = givenList.stream()
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.collect(collectingAndThen(toList(), Collections::unmodifiableList));
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System.out.println(result.getClass());
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}
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@Test
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public void whenCollectToImmutableList_thenSuccess() {
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List<Integer> list = IntStream.range(0, 9)
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.boxed()
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.collect(ImmutableList.toImmutableList());
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System.out.println(list.getClass());
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}
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@Test
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public void whenCollectToMyImmutableListCollector_thenSuccess() {
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List<String> givenList = Arrays.asList("a", "b", "c", "d");
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List<String> result = givenList.stream()
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.collect(MyImmutableListCollector.toImmutableList());
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System.out.println(result.getClass());
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}
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@Test
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public void whenPassingSupplier_thenSuccess() {
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List<String> givenList = Arrays.asList("a", "b", "c", "d");
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List<String> result = givenList.stream()
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.collect(MyImmutableListCollector.toImmutableList(LinkedList::new));
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System.out.println(result.getClass());
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}
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}
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