diff --git a/core-java-modules/core-java-collections-2/README.md b/core-java-modules/core-java-collections-2/README.md
index d482ed7773..644cc93be7 100644
--- a/core-java-modules/core-java-collections-2/README.md
+++ b/core-java-modules/core-java-collections-2/README.md
@@ -13,3 +13,4 @@
- [Getting the Size of an Iterable in Java](https://www.baeldung.com/java-iterable-size)
- [Java Null-Safe Streams from Collections](https://www.baeldung.com/java-null-safe-streams-from-collections)
- [Differences Between Iterator and Iterable and How to Use Them?](https://www.baeldung.com/java-iterator-vs-iterable)
+- More articles: [[<-- prev]](/core-java-modules/core-java-collections-1) [[next -->]](/core-java-modules/core-java-collections-3)
\ No newline at end of file
diff --git a/core-java-modules/core-java-collections-4/README.md b/core-java-modules/core-java-collections-4/README.md
index f3a7d87403..460af21179 100644
--- a/core-java-modules/core-java-collections-4/README.md
+++ b/core-java-modules/core-java-collections-4/README.md
@@ -7,7 +7,6 @@
- [ArrayList vs. LinkedList vs. HashMap in Java](https://www.baeldung.com/java-arraylist-vs-linkedlist-vs-hashmap)
- [Java Deque vs. Stack](https://www.baeldung.com/java-deque-vs-stack)
- [Collection.toArray(new T[0]) or .toArray(new T[size])](https://www.baeldung.com/java-collection-toarray-methods)
-- [Create an Empty Map in Java](https://www.baeldung.com/java-create-empty-map)
- [Sorting Objects in a List by Date](https://www.baeldung.com/java-sort-list-by-date)
- [Fixed Size Queue Implementations in Java](https://www.baeldung.com/java-fixed-size-queue)
- [Difference Between Java Enumeration and Iterator](https://www.baeldung.com/java-enumeration-vs-iterator)
@@ -15,4 +14,4 @@
- [Guide to Java PriorityQueue](https://www.baeldung.com/java-priorityqueue)
- [Java Generics PECS – Producer Extends Consumer Super](https://www.baeldung.com/java-generics-pecs)
- [Reversing a Stack in Java](https://www.baeldung.com/java-reversing-a-stack)
-- [Sorting a HashSet in Java](https://www.baeldung.com/java-sort-hashset)
+- More articles: [[<-- prev]](/core-java-modules/core-java-collections-3)
\ No newline at end of file
diff --git a/core-java-modules/core-java-collections-4/pom.xml b/core-java-modules/core-java-collections-4/pom.xml
index 9f1439b850..e88d5a6740 100644
--- a/core-java-modules/core-java-collections-4/pom.xml
+++ b/core-java-modules/core-java-collections-4/pom.xml
@@ -25,6 +25,12 @@
commons-lang3
${commons-lang3.version}
+
+ org.junit.platform
+ junit-platform-runner
+ ${junit-platform.version}
+ test
+
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/HashMapUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/HashMapUnitTest.java
index 3b595472e0..7d4ec8249c 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/HashMapUnitTest.java
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/HashMapUnitTest.java
@@ -2,9 +2,7 @@ package com.baeldung.collections.comparation;
import org.junit.jupiter.api.Test;
-import java.util.Arrays;
import java.util.HashMap;
-import java.util.LinkedList;
import java.util.Map;
import static org.assertj.core.api.Assertions.assertThat;
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/LinkedListUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/LinkedListUnitTest.java
index aa6b7fa923..00a188737d 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/LinkedListUnitTest.java
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/LinkedListUnitTest.java
@@ -2,10 +2,8 @@ package com.baeldung.collections.comparation;
import org.junit.jupiter.api.Test;
-import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
-import java.util.List;
import static org.assertj.core.api.Assertions.assertThat;
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/EmployeeSortingByDateUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/EmployeeSortingByDateUnitTest.java
index 250fb7b62b..de2f3d8ca7 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/EmployeeSortingByDateUnitTest.java
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/EmployeeSortingByDateUnitTest.java
@@ -10,7 +10,7 @@ import java.util.Date;
import java.util.List;
import org.apache.commons.lang.time.DateUtils;
import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
public class EmployeeSortingByDateUnitTest {
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/multiple/ComparatorsUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/multiple/ComparatorsUnitTest.java
index 4608730567..e1297456be 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/multiple/ComparatorsUnitTest.java
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/multiple/ComparatorsUnitTest.java
@@ -5,8 +5,9 @@ import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;
-import org.junit.Test;
+
import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
public class ComparatorsUnitTest {
@Test
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/stackreversal/StackReversalUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/stackreversal/StackReversalUnitTest.java
index 7ad0b71028..ccadc4e7d3 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/stackreversal/StackReversalUnitTest.java
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/stackreversal/StackReversalUnitTest.java
@@ -1,10 +1,12 @@
package com.baeldung.stackreversal;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
import com.baeldung.collections.sorting.Employee;
import com.baeldung.collections.stackreversal.ReverseStackUsingQueue;
import com.baeldung.collections.stackreversal.ReverseStackUsingRecursion;
-import org.junit.Assert;
-import org.junit.Test;
+
+import org.junit.jupiter.api.Test;
import java.util.*;
import java.util.stream.Collectors;
@@ -15,7 +17,7 @@ public class StackReversalUnitTest {
ReverseStackUsingQueue reverseStack = new ReverseStackUsingQueue();
Stack originalStack = generateStackFromGivenList(Arrays.stream(new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}).boxed().collect(Collectors.toList()), new Stack());
Stack reverseList = generateStackFromGivenList(Arrays.stream(new int[]{10, 9, 8, 7, 6, 5, 4, 3, 2, 1}).boxed().collect(Collectors.toList()), new Stack());
- Assert.assertEquals(reverseStack.reverseIntegerStack(originalStack), reverseList);
+ assertEquals(reverseStack.reverseIntegerStack(originalStack), reverseList);
}
@Test
@@ -26,7 +28,7 @@ public class StackReversalUnitTest {
Collections.reverse(listOfWordsReversed);
Stack originalStack = generateStackFromGivenList(listOfWords, new Stack());
Stack reversedStack = generateStackFromGivenList(listOfWordsReversed, new Stack());
- Assert.assertEquals(stackReversal.reverseStringStack(originalStack), reversedStack);
+ assertEquals(stackReversal.reverseStringStack(originalStack), reversedStack);
}
@Test
@@ -43,7 +45,7 @@ public class StackReversalUnitTest {
Collections.reverse(employeeReversed);
Stack originalStack = generateStackFromGivenList(employeeList, new Stack());
Stack reverseStack = generateStackFromGivenList(employeeReversed, new Stack());
- Assert.assertEquals(stackReversal.reverseEmployeeStack(originalStack), reverseStack);
+ assertEquals(stackReversal.reverseEmployeeStack(originalStack), reverseStack);
}
@Test
@@ -51,7 +53,7 @@ public class StackReversalUnitTest {
ReverseStackUsingRecursion reverseStack = new ReverseStackUsingRecursion();
Stack originalStack = generateStackFromGivenList(Arrays.stream(new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}).boxed().collect(Collectors.toList()), new Stack());
Stack reversedStack = generateStackFromGivenList(Arrays.stream(new int[]{10, 9, 8, 7, 6, 5, 4, 3, 2, 1}).boxed().collect(Collectors.toList()), new Stack());
- Assert.assertEquals(reverseStack.reverseIntegerStack(originalStack), reversedStack);
+ assertEquals(reverseStack.reverseIntegerStack(originalStack), reversedStack);
}
private Stack generateStackFromGivenList(List elements, Stack stack){
diff --git a/core-java-modules/core-java-collections-maps/README.md b/core-java-modules/core-java-collections-maps/README.md
index 15cb32fbe8..034c71ba9a 100644
--- a/core-java-modules/core-java-collections-maps/README.md
+++ b/core-java-modules/core-java-collections-maps/README.md
@@ -12,4 +12,5 @@ This module contains articles about Map data structures in Java.
- [Immutable Map Implementations in Java](https://www.baeldung.com/java-immutable-maps)
- [Guide to Apache Commons MultiValuedMap](https://www.baeldung.com/apache-commons-multi-valued-map)
- [The Java HashMap Under the Hood](https://www.baeldung.com/java-hashmap-advanced)
+- [Create an Empty Map in Java](https://www.baeldung.com/java-create-empty-map)
- More articles: [[next -->]](/core-java-modules/core-java-collections-maps-2)
diff --git a/core-java-modules/core-java-collections-maps/pom.xml b/core-java-modules/core-java-collections-maps/pom.xml
index 34b878df53..3a1bf0d8a1 100644
--- a/core-java-modules/core-java-collections-maps/pom.xml
+++ b/core-java-modules/core-java-collections-maps/pom.xml
@@ -20,6 +20,12 @@
commons-collections4
${commons-collections4.version}
+
+ org.junit.platform
+ junit-platform-runner
+ ${junit-platform.version}
+ test
+
\ No newline at end of file
diff --git a/core-java-modules/core-java-collections-4/src/main/java/com/baeldung/maps/initialize/EmptyMapInitializer.java b/core-java-modules/core-java-collections-maps/src/main/java/com/baeldung/map/EmptyMapInitializer.java
similarity index 97%
rename from core-java-modules/core-java-collections-4/src/main/java/com/baeldung/maps/initialize/EmptyMapInitializer.java
rename to core-java-modules/core-java-collections-maps/src/main/java/com/baeldung/map/EmptyMapInitializer.java
index 78819cc21e..106de799e7 100644
--- a/core-java-modules/core-java-collections-4/src/main/java/com/baeldung/maps/initialize/EmptyMapInitializer.java
+++ b/core-java-modules/core-java-collections-maps/src/main/java/com/baeldung/map/EmptyMapInitializer.java
@@ -1,7 +1,5 @@
-package com.baeldung.maps.initialize;
+package com.baeldung.map;
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Maps;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
@@ -10,6 +8,9 @@ import java.util.NavigableMap;
import java.util.SortedMap;
import java.util.TreeMap;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
+
public class EmptyMapInitializer {
public static Map articleMap;
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/maps/initialize/EmptyMapInitializerUnitTest.java b/core-java-modules/core-java-collections-maps/src/test/java/com/baeldung/map/EmptyMapInitializerUnitTest.java
similarity index 96%
rename from core-java-modules/core-java-collections-4/src/test/java/com/baeldung/maps/initialize/EmptyMapInitializerUnitTest.java
rename to core-java-modules/core-java-collections-maps/src/test/java/com/baeldung/map/EmptyMapInitializerUnitTest.java
index 57183734cb..94a70cdd5d 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/maps/initialize/EmptyMapInitializerUnitTest.java
+++ b/core-java-modules/core-java-collections-maps/src/test/java/com/baeldung/map/EmptyMapInitializerUnitTest.java
@@ -1,11 +1,12 @@
-package com.baeldung.maps.initialize;
-
-import java.util.Map;
-import org.junit.Test;
+package com.baeldung.map;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.util.Map;
+
+import org.junit.Test;
+
public class EmptyMapInitializerUnitTest {
@Test(expected=UnsupportedOperationException.class)
diff --git a/core-java-modules/core-java-collections-set-2/README.md b/core-java-modules/core-java-collections-set-2/README.md
index 48c70084ca..a11329365a 100644
--- a/core-java-modules/core-java-collections-set-2/README.md
+++ b/core-java-modules/core-java-collections-set-2/README.md
@@ -2,3 +2,5 @@
- [Using Streams to Collect Into a TreeSet](https://www.baeldung.com/java-stream-collect-into-treeset)
- [A Guide to LinkedHashSet in Java](https://www.baeldung.com/java-linkedhashset)
+- [Sorting a HashSet in Java](https://www.baeldung.com/java-sort-hashset)
+- More articles: [[<-- prev]](/core-java-modules/core-java-collections-set)
\ No newline at end of file
diff --git a/core-java-modules/core-java-collections-set-2/pom.xml b/core-java-modules/core-java-collections-set-2/pom.xml
index d3f54554e0..b1aadb0c22 100644
--- a/core-java-modules/core-java-collections-set-2/pom.xml
+++ b/core-java-modules/core-java-collections-set-2/pom.xml
@@ -15,6 +15,12 @@
+
+ org.junit.platform
+ junit-platform-runner
+ ${junit-platform.version}
+ test
+
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/HashSetUnitTest.java b/core-java-modules/core-java-collections-set-2/src/test/java/com/baeldung/hashset/sorting/HashSetUnitTest.java
similarity index 97%
rename from core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/HashSetUnitTest.java
rename to core-java-modules/core-java-collections-set-2/src/test/java/com/baeldung/hashset/sorting/HashSetUnitTest.java
index de0b084216..ebb400570f 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/sorting/HashSetUnitTest.java
+++ b/core-java-modules/core-java-collections-set-2/src/test/java/com/baeldung/hashset/sorting/HashSetUnitTest.java
@@ -1,4 +1,4 @@
-package com.baeldung.collections.sorting;
+package com.baeldung.hashset.sorting;
import static org.assertj.core.api.Assertions.assertThat;