From 92ad8123f1288f051fe20b4cbd331a4a41867ba6 Mon Sep 17 00:00:00 2001 From: pivovarit Date: Tue, 7 Feb 2017 19:32:09 +0100 Subject: [PATCH] Refactor Java8GroupingByCollectorUnitTest --- .../Java8GroupingByCollectorUnitTest.java | 227 ++++++++++++------ 1 file changed, 154 insertions(+), 73 deletions(-) diff --git a/core-java/src/test/java/com/baeldung/java8/Java8GroupingByCollectorUnitTest.java b/core-java/src/test/java/com/baeldung/java8/Java8GroupingByCollectorUnitTest.java index 178cd72542..4452b4db9a 100644 --- a/core-java/src/test/java/com/baeldung/java8/Java8GroupingByCollectorUnitTest.java +++ b/core-java/src/test/java/com/baeldung/java8/Java8GroupingByCollectorUnitTest.java @@ -1,52 +1,47 @@ package com.baeldung.java8; -import static java.util.Comparator.comparingInt; -import static java.util.stream.Collectors.averagingInt; -import static java.util.stream.Collectors.counting; -import static java.util.stream.Collectors.groupingBy; -import static java.util.stream.Collectors.groupingByConcurrent; -import static java.util.stream.Collectors.joining; -import static java.util.stream.Collectors.mapping; -import static java.util.stream.Collectors.maxBy; -import static java.util.stream.Collectors.summarizingInt; -import static java.util.stream.Collectors.summingInt; -import static java.util.stream.Collectors.toList; -import static java.util.stream.Collectors.toSet; -import static org.junit.Assert.assertEquals; -import static org.junit.Assert.assertNull; -import static org.junit.Assert.assertTrue; - -import java.util.Arrays; -import java.util.EnumMap; -import java.util.IntSummaryStatistics; -import java.util.List; -import java.util.Map; -import java.util.Optional; -import java.util.Set; -import java.util.concurrent.ConcurrentMap; - -import org.junit.Test; - import com.baeldung.java_8_features.groupingby.BlogPost; import com.baeldung.java_8_features.groupingby.BlogPostType; +import org.junit.Test; + +import java.util.*; +import java.util.concurrent.ConcurrentMap; + +import static java.util.Comparator.comparingInt; +import static java.util.stream.Collectors.*; +import static org.junit.Assert.*; public class Java8GroupingByCollectorUnitTest { - private static final List POSTS = Arrays.asList(new BlogPost("News item 1", "Author 1", BlogPostType.NEWS, 15), new BlogPost("Tech review 1", "Author 2", BlogPostType.REVIEW, 5), - new BlogPost("Programming guide", "Author 1", BlogPostType.GUIDE, 20), new BlogPost("News item 2", "Author 2", BlogPostType.NEWS, 35), new BlogPost("Tech review 2", "Author 1", BlogPostType.REVIEW, 15)); + private static final List posts = Arrays.asList( + new BlogPost("News item 1", "Author 1", BlogPostType.NEWS, 15), + new BlogPost("Tech review 1", "Author 2", BlogPostType.REVIEW, 5), + new BlogPost("Programming guide", "Author 1", BlogPostType.GUIDE, 20), + new BlogPost("News item 2", "Author 2", BlogPostType.NEWS, 35), + new BlogPost("Tech review 2", "Author 1", BlogPostType.REVIEW, 15)); @Test public void givenAListOfPosts_whenGroupedByType_thenGetAMapBetweenTypeAndPosts() { - Map> postsPerType = POSTS.stream().collect(groupingBy(BlogPost::getType)); + Map> postsPerType = posts + .stream() + .collect(groupingBy(BlogPost::getType)); - assertEquals(2, postsPerType.get(BlogPostType.NEWS).size()); - assertEquals(1, postsPerType.get(BlogPostType.GUIDE).size()); - assertEquals(2, postsPerType.get(BlogPostType.REVIEW).size()); + assertEquals(2, postsPerType + .get(BlogPostType.NEWS) + .size()); + assertEquals(1, postsPerType + .get(BlogPostType.GUIDE) + .size()); + assertEquals(2, postsPerType + .get(BlogPostType.REVIEW) + .size()); } @Test public void givenAListOfPosts_whenGroupedByTypeAndTheirTitlesAreJoinedInAString_thenGetAMapBetweenTypeAndCsvTitles() { - Map postsPerType = POSTS.stream().collect(groupingBy(BlogPost::getType, mapping(BlogPost::getTitle, joining(", ", "Post titles: [", "]")))); + Map postsPerType = posts + .stream() + .collect(groupingBy(BlogPost::getType, mapping(BlogPost::getTitle, joining(", ", "Post titles: [", "]")))); assertEquals("Post titles: [News item 1, News item 2]", postsPerType.get(BlogPostType.NEWS)); assertEquals("Post titles: [Programming guide]", postsPerType.get(BlogPostType.GUIDE)); @@ -55,88 +50,174 @@ public class Java8GroupingByCollectorUnitTest { @Test public void givenAListOfPosts_whenGroupedByTypeAndSumTheLikes_thenGetAMapBetweenTypeAndPostLikes() { - Map likesPerType = POSTS.stream().collect(groupingBy(BlogPost::getType, summingInt(BlogPost::getLikes))); + Map likesPerType = posts + .stream() + .collect(groupingBy(BlogPost::getType, summingInt(BlogPost::getLikes))); - assertEquals(50, likesPerType.get(BlogPostType.NEWS).intValue()); - assertEquals(20, likesPerType.get(BlogPostType.REVIEW).intValue()); - assertEquals(20, likesPerType.get(BlogPostType.GUIDE).intValue()); + assertEquals(50, likesPerType + .get(BlogPostType.NEWS) + .intValue()); + assertEquals(20, likesPerType + .get(BlogPostType.REVIEW) + .intValue()); + assertEquals(20, likesPerType + .get(BlogPostType.GUIDE) + .intValue()); } @Test public void givenAListOfPosts_whenGroupedByTypeInAnEnumMap_thenGetAnEnumMapBetweenTypeAndPosts() { - EnumMap> postsPerType = POSTS.stream().collect(groupingBy(BlogPost::getType, () -> new EnumMap<>(BlogPostType.class), toList())); + EnumMap> postsPerType = posts + .stream() + .collect(groupingBy(BlogPost::getType, () -> new EnumMap<>(BlogPostType.class), toList())); - assertEquals(2, postsPerType.get(BlogPostType.NEWS).size()); - assertEquals(1, postsPerType.get(BlogPostType.GUIDE).size()); - assertEquals(2, postsPerType.get(BlogPostType.REVIEW).size()); + assertEquals(2, postsPerType + .get(BlogPostType.NEWS) + .size()); + assertEquals(1, postsPerType + .get(BlogPostType.GUIDE) + .size()); + assertEquals(2, postsPerType + .get(BlogPostType.REVIEW) + .size()); } @Test public void givenAListOfPosts_whenGroupedByTypeInSets_thenGetAMapBetweenTypesAndSetsOfPosts() { - Map> postsPerType = POSTS.stream().collect(groupingBy(BlogPost::getType, toSet())); + Map> postsPerType = posts + .stream() + .collect(groupingBy(BlogPost::getType, toSet())); - assertEquals(2, postsPerType.get(BlogPostType.NEWS).size()); - assertEquals(1, postsPerType.get(BlogPostType.GUIDE).size()); - assertEquals(2, postsPerType.get(BlogPostType.REVIEW).size()); + assertEquals(2, postsPerType + .get(BlogPostType.NEWS) + .size()); + assertEquals(1, postsPerType + .get(BlogPostType.GUIDE) + .size()); + assertEquals(2, postsPerType + .get(BlogPostType.REVIEW) + .size()); } @Test public void givenAListOfPosts_whenGroupedByTypeConcurrently_thenGetAMapBetweenTypeAndPosts() { - ConcurrentMap> postsPerType = POSTS.parallelStream().collect(groupingByConcurrent(BlogPost::getType)); + ConcurrentMap> postsPerType = posts + .parallelStream() + .collect(groupingByConcurrent(BlogPost::getType)); - assertEquals(2, postsPerType.get(BlogPostType.NEWS).size()); - assertEquals(1, postsPerType.get(BlogPostType.GUIDE).size()); - assertEquals(2, postsPerType.get(BlogPostType.REVIEW).size()); + assertEquals(2, postsPerType + .get(BlogPostType.NEWS) + .size()); + assertEquals(1, postsPerType + .get(BlogPostType.GUIDE) + .size()); + assertEquals(2, postsPerType + .get(BlogPostType.REVIEW) + .size()); } @Test public void givenAListOfPosts_whenGroupedByTypeAndAveragingLikes_thenGetAMapBetweenTypeAndAverageNumberOfLikes() { - Map averageLikesPerType = POSTS.stream().collect(groupingBy(BlogPost::getType, averagingInt(BlogPost::getLikes))); + Map averageLikesPerType = posts + .stream() + .collect(groupingBy(BlogPost::getType, averagingInt(BlogPost::getLikes))); - assertEquals(25, averageLikesPerType.get(BlogPostType.NEWS).intValue()); - assertEquals(20, averageLikesPerType.get(BlogPostType.GUIDE).intValue()); - assertEquals(10, averageLikesPerType.get(BlogPostType.REVIEW).intValue()); + assertEquals(25, averageLikesPerType + .get(BlogPostType.NEWS) + .intValue()); + assertEquals(20, averageLikesPerType + .get(BlogPostType.GUIDE) + .intValue()); + assertEquals(10, averageLikesPerType + .get(BlogPostType.REVIEW) + .intValue()); } @Test public void givenAListOfPosts_whenGroupedByTypeAndCounted_thenGetAMapBetweenTypeAndNumberOfPosts() { - Map numberOfPostsPerType = POSTS.stream().collect(groupingBy(BlogPost::getType, counting())); + Map numberOfPostsPerType = posts + .stream() + .collect(groupingBy(BlogPost::getType, counting())); - assertEquals(2, numberOfPostsPerType.get(BlogPostType.NEWS).intValue()); - assertEquals(1, numberOfPostsPerType.get(BlogPostType.GUIDE).intValue()); - assertEquals(2, numberOfPostsPerType.get(BlogPostType.REVIEW).intValue()); + assertEquals(2, numberOfPostsPerType + .get(BlogPostType.NEWS) + .intValue()); + assertEquals(1, numberOfPostsPerType + .get(BlogPostType.GUIDE) + .intValue()); + assertEquals(2, numberOfPostsPerType + .get(BlogPostType.REVIEW) + .intValue()); } @Test public void givenAListOfPosts_whenGroupedByTypeAndMaxingLikes_thenGetAMapBetweenTypeAndMaximumNumberOfLikes() { - Map> maxLikesPerPostType = POSTS.stream().collect(groupingBy(BlogPost::getType, maxBy(comparingInt(BlogPost::getLikes)))); + Map> maxLikesPerPostType = posts + .stream() + .collect(groupingBy(BlogPost::getType, maxBy(comparingInt(BlogPost::getLikes)))); - assertTrue(maxLikesPerPostType.get(BlogPostType.NEWS).isPresent()); - assertEquals(35, maxLikesPerPostType.get(BlogPostType.NEWS).get().getLikes()); + assertTrue(maxLikesPerPostType + .get(BlogPostType.NEWS) + .isPresent()); + assertEquals(35, maxLikesPerPostType + .get(BlogPostType.NEWS) + .get() + .getLikes()); - assertTrue(maxLikesPerPostType.get(BlogPostType.GUIDE).isPresent()); - assertEquals(20, maxLikesPerPostType.get(BlogPostType.GUIDE).get().getLikes()); + assertTrue(maxLikesPerPostType + .get(BlogPostType.GUIDE) + .isPresent()); + assertEquals(20, maxLikesPerPostType + .get(BlogPostType.GUIDE) + .get() + .getLikes()); - assertTrue(maxLikesPerPostType.get(BlogPostType.REVIEW).isPresent()); - assertEquals(15, maxLikesPerPostType.get(BlogPostType.REVIEW).get().getLikes()); + assertTrue(maxLikesPerPostType + .get(BlogPostType.REVIEW) + .isPresent()); + assertEquals(15, maxLikesPerPostType + .get(BlogPostType.REVIEW) + .get() + .getLikes()); } @Test public void givenAListOfPosts_whenGroupedByAuthorAndThenByType_thenGetAMapBetweenAuthorAndMapsBetweenTypeAndBlogPosts() { - Map>> map = POSTS.stream().collect(groupingBy(BlogPost::getAuthor, groupingBy(BlogPost::getType))); + Map>> map = posts + .stream() + .collect(groupingBy(BlogPost::getAuthor, groupingBy(BlogPost::getType))); - assertEquals(1, map.get("Author 1").get(BlogPostType.NEWS).size()); - assertEquals(1, map.get("Author 1").get(BlogPostType.GUIDE).size()); - assertEquals(1, map.get("Author 1").get(BlogPostType.REVIEW).size()); + assertEquals(1, map + .get("Author 1") + .get(BlogPostType.NEWS) + .size()); + assertEquals(1, map + .get("Author 1") + .get(BlogPostType.GUIDE) + .size()); + assertEquals(1, map + .get("Author 1") + .get(BlogPostType.REVIEW) + .size()); - assertEquals(1, map.get("Author 2").get(BlogPostType.NEWS).size()); - assertEquals(1, map.get("Author 2").get(BlogPostType.REVIEW).size()); - assertNull(map.get("Author 2").get(BlogPostType.GUIDE)); + assertEquals(1, map + .get("Author 2") + .get(BlogPostType.NEWS) + .size()); + assertEquals(1, map + .get("Author 2") + .get(BlogPostType.REVIEW) + .size()); + assertNull(map + .get("Author 2") + .get(BlogPostType.GUIDE)); } @Test public void givenAListOfPosts_whenGroupedByTypeAndSummarizingLikes_thenGetAMapBetweenTypeAndSummary() { - Map likeStatisticsPerType = POSTS.stream().collect(groupingBy(BlogPost::getType, summarizingInt(BlogPost::getLikes))); + Map likeStatisticsPerType = posts + .stream() + .collect(groupingBy(BlogPost::getType, summarizingInt(BlogPost::getLikes))); IntSummaryStatistics newsLikeStatistics = likeStatisticsPerType.get(BlogPostType.NEWS);