From ded13f14b22653a8448b62b731a28ce22110d912 Mon Sep 17 00:00:00 2001 From: Daniel Strmecki Date: Tue, 11 Aug 2020 19:29:46 +0200 Subject: [PATCH] Feature/bael 4280 diff between lists (#9600) * BAEL-4280: Initial commit for finding diff between lists * BAEL-4280: Format * BAEL-4280: Refactor * BAEL-4280: Refactor not to use private methods * BAEL-4280: Refactor based on editor comments * BAEL-4280: Review round 2 * BAEL-4280: Use assertj * BAEL-4280: Use assertj * BAEL-4280: Shorter names for tests * BAEL-4280: Remove HashSet as its not used anymore * BAEL-4280: Use containsExactlyInAnyOrder for Set example * BAEL-4280: Remove distinct method call * BAEL-4280: Move impl to test * BAEL-4280: Use containsExactlyInAnyOrder * BAEL-4280: Rename test methods --- .../core-java-collections-list-3/pom.xml | 6 ++ .../FindDifferencesBetweenListsUnitTest.java | 96 +++++++++++++++++++ 2 files changed, 102 insertions(+) create mode 100644 core-java-modules/core-java-collections-list-3/src/test/java/com/baeldung/list/difference/FindDifferencesBetweenListsUnitTest.java diff --git a/core-java-modules/core-java-collections-list-3/pom.xml b/core-java-modules/core-java-collections-list-3/pom.xml index 373190a130..e1cf645c8a 100644 --- a/core-java-modules/core-java-collections-list-3/pom.xml +++ b/core-java-modules/core-java-collections-list-3/pom.xml @@ -21,6 +21,12 @@ commons-collections4 ${commons-collections4.version} + + com.google.guava + guava + ${guava.version} + compile + org.assertj assertj-core diff --git a/core-java-modules/core-java-collections-list-3/src/test/java/com/baeldung/list/difference/FindDifferencesBetweenListsUnitTest.java b/core-java-modules/core-java-collections-list-3/src/test/java/com/baeldung/list/difference/FindDifferencesBetweenListsUnitTest.java new file mode 100644 index 0000000000..ceeff5e442 --- /dev/null +++ b/core-java-modules/core-java-collections-list-3/src/test/java/com/baeldung/list/difference/FindDifferencesBetweenListsUnitTest.java @@ -0,0 +1,96 @@ +package com.baeldung.list.difference; + +import com.google.common.collect.Sets; +import org.apache.commons.collections4.CollectionUtils; +import org.junit.Test; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; +import java.util.stream.Collectors; + +import static org.junit.jupiter.api.Assertions.*; +import static org.assertj.core.api.Assertions.*; + +public class FindDifferencesBetweenListsUnitTest { + + private static final List listOne = Arrays.asList("Jack", "Tom", "Sam", "John", "James", "Jack"); + private static final List listTwo = Arrays.asList("Jack", "Daniel", "Sam", "Alan", "James", "George"); + + @Test + public void givenLists_whenUsingPlainJavaImpl_thenDifferencesAreFound() { + List differences = new ArrayList<>(listOne); + differences.removeAll(listTwo); + assertEquals(2, differences.size()); + assertThat(differences).containsExactly("Tom", "John"); + } + + @Test + public void givenReverseLists_whenUsingPlainJavaImpl_thenDifferencesAreFound() { + List differences = new ArrayList<>(listTwo); + differences.removeAll(listOne); + assertEquals(3, differences.size()); + assertThat(differences).containsExactly("Daniel", "Alan", "George"); + } + + @Test + public void givenLists_whenUsingJavaStreams_thenDifferencesAreFound() { + List differences = listOne.stream() + .filter(element -> !listTwo.contains(element)) + .collect(Collectors.toList()); + assertEquals(2, differences.size()); + assertThat(differences).containsExactly("Tom", "John"); + } + + @Test + public void givenReverseLists_whenUsingJavaStreams_thenDifferencesAreFound() { + List differences = listTwo.stream() + .filter(element -> !listOne.contains(element)) + .collect(Collectors.toList()); + assertEquals(3, differences.size()); + assertThat(differences).containsExactly("Daniel", "Alan", "George"); + } + + @Test + public void givenLists_whenUsingGoogleGuava_thenDifferencesAreFound() { + List differences = new ArrayList<>(Sets.difference(Sets.newHashSet(listOne), Sets.newHashSet(listTwo))); + assertEquals(2, differences.size()); + assertThat(differences).containsExactlyInAnyOrder("Tom", "John"); + } + + @Test + public void givenReverseLists_whenUsingGoogleGuava_thenDifferencesAreFound() { + List differences = new ArrayList<>(Sets.difference(Sets.newHashSet(listTwo), Sets.newHashSet(listOne))); + assertEquals(3, differences.size()); + assertThat(differences).containsExactlyInAnyOrder("Daniel", "Alan", "George"); + } + + @Test + public void givenLists_whenUsingApacheCommons_thenDifferencesAreFound() { + List differences = new ArrayList<>((CollectionUtils.removeAll(listOne, listTwo))); + assertEquals(2, differences.size()); + assertThat(differences).containsExactly("Tom", "John"); + } + + @Test + public void givenReverseLists_whenUsingApacheCommons_thenDifferencesAreFound() { + List differences = new ArrayList<>((CollectionUtils.removeAll(listTwo, listOne))); + assertEquals(3, differences.size()); + assertThat(differences).containsExactly("Daniel", "Alan", "George"); + } + + @Test + public void givenLists_whenUsingPlainJavaImpl_thenDifferencesWithDuplicatesAreFound() { + List differences = new ArrayList<>(listOne); + listTwo.forEach(differences::remove); + assertThat(differences).containsExactly("Tom", "John", "Jack"); + } + + @Test + public void givenLists_whenUsingApacheCommons_thenDifferencesWithDuplicatesAreFound() { + List differences = new ArrayList<>(CollectionUtils.subtract(listOne, listTwo)); + assertEquals(3, differences.size()); + assertThat(differences).containsExactly("Tom", "John", "Jack"); + } + +}