[JAVA-26432] Update "Introduction to Java 8 Streams" article Clean up (#15038)

core-java-modules/core-java-streams-simple/src/test/java/com/baeldung/streams/Java8StreamsUnitTest.java

@@ -1,7 +1,11 @@
 package com.baeldung.streams;
 
-import org.junit.Before;
-import org.junit.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
 
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -11,14 +15,12 @@ import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import static org.junit.Assert.*;
+class Java8StreamsUnitTest {
 
-public class Java8StreamsUnitTest {
+    private static List<String> list;
 
-    private List<String> list;
-
-    @Before
-    public void init() {
+    @BeforeAll
+    public static void init() {
         list = new ArrayList<>();
         list.add("One");
         list.add("OneAndOnly");
@@ -42,60 +44,73 @@ public class Java8StreamsUnitTest {
         Stream<String> streamOf = Stream.of("a", "b", "c");
         assertEquals(streamOf.count(), 3);
 
-        long count = list.stream().distinct().count();
+        long count = list.stream()
+            .distinct()
+            .count();
         assertEquals(count, 9);
     }
 
     @Test
-    public void checkStreamCount_whenOperationFilter_thanCorrect() {
-        Stream<String> streamFilter = list.stream().filter(element -> element.isEmpty());
+    void checkStreamCount_whenOperationFilter_thanCorrect() {
+        Stream<String> streamFilter = list.stream()
+            .filter(element -> element.isEmpty());
         assertEquals(streamFilter.count(), 2);
     }
 
     @Test
-    public void checkStreamCount_whenOperationMap_thanCorrect() {
+    void checkStreamCount_whenOperationMap_thanCorrect() {
         List<String> uris = new ArrayList<>();
         uris.add("C:\\My.txt");
-        Stream<Path> streamMap = uris.stream().map(uri -> Paths.get(uri));
+        Stream<Path> streamMap = uris.stream()
+            .map(uri -> Paths.get(uri));
         assertEquals(streamMap.count(), 1);
 
         List<Detail> details = new ArrayList<>();
         details.add(new Detail());
         details.add(new Detail());
-        Stream<String> streamFlatMap = details.stream().flatMap(detail -> detail.getParts().stream());
+        Stream<String> streamFlatMap = details.stream()
+            .flatMap(detail -> detail.getParts()
+                .stream());
         assertEquals(streamFlatMap.count(), 4);
     }
 
     @Test
-    public void checkStreamCount_whenOperationMatch_thenCorrect() {
-        boolean isValid = list.stream().anyMatch(element -> element.contains("h"));
-        boolean isValidOne = list.stream().allMatch(element -> element.contains("h"));
-        boolean isValidTwo = list.stream().noneMatch(element -> element.contains("h"));
+    void checkStreamCount_whenOperationMatch_thenCorrect() {
+        boolean isValid = list.stream()
+            .anyMatch(element -> element.contains("h"));
+        boolean isValidOne = list.stream()
+            .allMatch(element -> element.contains("h"));
+        boolean isValidTwo = list.stream()
+            .noneMatch(element -> element.contains("h"));
         assertTrue(isValid);
         assertFalse(isValidOne);
         assertFalse(isValidTwo);
     }
 
     @Test
-    public void checkStreamReducedValue_whenOperationReduce_thenCorrect() {
+    void checkStreamReducedValue_whenOperationReduce_thenCorrect() {
         List<Integer> integers = new ArrayList<>();
         integers.add(1);
         integers.add(1);
         integers.add(1);
-        Integer reduced = integers.stream().reduce(23, (a, b) -> a + b);
+        Integer reduced = integers.stream()
+            .reduce(23, (a, b) -> a + b);
         assertTrue(reduced == 26);
     }
 
     @Test
-    public void checkStreamContains_whenOperationCollect_thenCorrect() {
-        List<String> resultList = list.stream().map(element -> element.toUpperCase()).collect(Collectors.toList());
+    void checkStreamContains_whenOperationCollect_thenCorrect() {
+        List<String> resultList = list.stream()
+            .map(element -> element.toUpperCase())
+            .collect(Collectors.toList());
         assertEquals(resultList.size(), list.size());
         assertTrue(resultList.contains(""));
     }
 
     @Test
     public void checkParallelStream_whenDoWork() {
-        list.parallelStream().forEach(element -> doWork(element));
+        list.parallelStream()
+            .forEach(element -> doWork(element));
     }
 
     private void doWork(String string) {