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BAEL-4944: Update code samples for the Removing all duplicates from a List in Java (#10717)

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Co-authored-by: Krzysztof Woyke <krzysztof.woyke.sp@lhsystems.com>
This commit is contained in:
kwoyke 2021-04-30 07:31:17 +02:00 committed by GitHub
parent 3b15e86fe6
commit 344dac3835
2 changed files with 39 additions and 15 deletions
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46
core-java-modules/core-java-collections-list/src/test/java/com/baeldung/collections/JavaCollectionCleanupUnitTest.java
View File

@ -1,11 +1,14 @@
package com.baeldung.collections;
import static org.hamcrest.Matchers.containsInAnyOrder;
import static org.hamcrest.Matchers.containsInRelativeOrder;
import static org.hamcrest.Matchers.hasSize;
import static org.junit.Assert.assertThat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import org.apache.commons.collections4.CollectionUtils;
@ -22,7 +25,7 @@ public class JavaCollectionCleanupUnitTest {
// tests - removing nulls
@Test
public final void givenListContainsNulls_whenRemovingNullsWithPlainJava_thenCorrect() {
public void givenListContainsNulls_whenRemovingNullsWithPlainJava_thenCorrect() {
final List<Integer> list = Lists.newArrayList(null, 1, null);
while (list.remove(null))
;
@ -31,7 +34,7 @@ public class JavaCollectionCleanupUnitTest {
}
@Test
public final void givenListContainsNulls_whenRemovingNullsWithPlainJavaAlternative_thenCorrect() {
public void givenListContainsNulls_whenRemovingNullsWithPlainJavaAlternative_thenCorrect() {
final List<Integer> list = Lists.newArrayList(null, 1, null);
list.removeAll(Collections.singleton(null));
@ -39,7 +42,7 @@ public class JavaCollectionCleanupUnitTest {
}
@Test
public final void givenListContainsNulls_whenRemovingNullsWithGuavaV1_thenCorrect() {
public void givenListContainsNulls_whenRemovingNullsWithGuavaV1_thenCorrect() {
final List<Integer> list = Lists.newArrayList(null, 1, null);
Iterables.removeIf(list, Predicates.isNull());
@ -47,7 +50,7 @@ public class JavaCollectionCleanupUnitTest {
}
@Test
public final void givenListContainsNulls_whenRemovingNullsWithGuavaV2_thenCorrect() {
public void givenListContainsNulls_whenRemovingNullsWithGuavaV2_thenCorrect() {
final List<Integer> list = Lists.newArrayList(null, 1, null, 2, 3);
final List<Integer> listWithoutNulls = Lists.newArrayList(Iterables.filter(list, Predicates.notNull()));
@ -55,7 +58,7 @@ public class JavaCollectionCleanupUnitTest {
}
@Test
public final void givenListContainsNulls_whenRemovingNullsWithCommonsCollections_thenCorrect() {
public void givenListContainsNulls_whenRemovingNullsWithCommonsCollections_thenCorrect() {
final List<Integer> list = Lists.newArrayList(null, 1, 2, null, 3, null);
CollectionUtils.filter(list, PredicateUtils.notNullPredicate());
@ -65,19 +68,38 @@ public class JavaCollectionCleanupUnitTest {
// tests - remove duplicates
@Test
public final void givenListContainsDuplicates_whenRemovingDuplicatesWithPlainJava_thenCorrect() {
final List<Integer> listWithDuplicates = Lists.newArrayList(0, 1, 2, 3, 0, 0);
public void givenListContainsDuplicates_whenRemovingDuplicatesWithPlainJava_thenCorrect() {
final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
final List<Integer> listWithoutDuplicates = new ArrayList<>(new HashSet<>(listWithDuplicates));
assertThat(listWithoutDuplicates, hasSize(4));
assertThat(listWithoutDuplicates, hasSize(5));
assertThat(listWithoutDuplicates, containsInAnyOrder(5, 0, 3, 1, 2));
}
@Test
public final void givenListContainsDuplicates_whenRemovingDuplicatesWithGuava_thenCorrect() {
final List<Integer> listWithDuplicates = Lists.newArrayList(0, 1, 2, 3, 0, 0);
final List<Integer> listWithoutDuplicates = Lists.newArrayList(Sets.newHashSet(listWithDuplicates));
public void givenListContainsDuplicates_whenRemovingDuplicatesPreservingOrderWithPlainJava_thenCorrect() {
final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
final List<Integer> listWithoutDuplicates = new ArrayList<>(new LinkedHashSet<>(listWithDuplicates));
assertThat(listWithoutDuplicates, hasSize(4));
assertThat(listWithoutDuplicates, hasSize(5));
assertThat(listWithoutDuplicates, containsInRelativeOrder(5, 0, 3, 1, 2));
}
@Test
public void givenListContainsDuplicates_whenRemovingDuplicatesWithGuava_thenCorrect() {
final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
final List<Integer> listWithoutDuplicates = Lists.newArrayList(Sets.newHashSet(listWithDuplicates));
assertThat(listWithoutDuplicates, hasSize(5));
assertThat(listWithoutDuplicates, containsInAnyOrder(5, 0, 3, 1, 2));
}
@Test
public void givenListContainsDuplicates_whenRemovingDuplicatesPreservingOrderWithGuava_thenCorrect() {
final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
final List<Integer> listWithoutDuplicates = Lists.newArrayList(Sets.newLinkedHashSet(listWithDuplicates));
assertThat(listWithoutDuplicates, hasSize(5));
assertThat(listWithoutDuplicates, containsInRelativeOrder(5, 0, 3, 1, 2));
}
}

8
core-java-modules/core-java-collections-list/src/test/java/com/baeldung/java8/Java8CollectionCleanupUnitTest.java
View File

@ -7,6 +7,7 @@ import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import static org.hamcrest.Matchers.containsInAnyOrder;
import static org.hamcrest.Matchers.hasSize;
import static org.junit.Assert.assertThat;
@ -40,10 +41,11 @@ public class Java8CollectionCleanupUnitTest {
@Test
public void givenListContainsDuplicates_whenRemovingDuplicatesWithJava8_thenCorrect() {
final List<Integer> listWithDuplicates = Lists.newArrayList(1, 1, 2, 2, 3, 3);
final List<Integer> listWithoutDuplicates = listWithDuplicates.parallelStream().distinct().collect(Collectors.toList());
final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
final List<Integer> listWithoutDuplicates = listWithDuplicates.stream().distinct().collect(Collectors.toList());
assertThat(listWithoutDuplicates, hasSize(3));
assertThat(listWithoutDuplicates, hasSize(5));
assertThat(listWithoutDuplicates, containsInAnyOrder(5, 0, 3, 1, 2));
}
}