BAEL-5163: HashMap - keySet vs entrySet vs values methods (#11301)

* Hexagonal Architecture in Java

* Refactor Hexagonal Architecture in Java

* Refactor Hexagonal Architecture in Java

* BAEL-5163: HashMap - keySet vs entrySet vs values methods

* BAEL-5163: HashMap - keySet vs entrySet vs values methods

* Revert "Hexagonal Architecture in Java"

This reverts commit 1add21c1

* BAEL-5163: HashMap - keySet vs entrySet vs values methods

* BAEL-5163: HashMap - keySet vs entrySet vs values methods"

java-collections-maps-3/src/test/java/com/baeldung/map/keysetValuesEntrySet/EntrySetExampleUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.map.keysetValuesEntrySet;
+
+import org.junit.Test;
+
+import java.util.AbstractMap.SimpleEntry;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class EntrySetExampleUnitTest {
+
+    @Test
+    public void givenHashMap_whenEntrySetApplied_thenShouldReturnSetOfEntries() {
+
+        Map<String, Integer> map = new HashMap<>();
+        map.put("one", 1);
+        map.put("two", 2);
+
+        Set<Map.Entry<String, Integer>> actualValues = map.entrySet();
+
+        assertEquals(2, actualValues.size());
+        assertTrue(actualValues.contains(new SimpleEntry<>("one", 1)));
+        assertTrue(actualValues.contains(new SimpleEntry<>("two", 2)));
+
+    }
+
+}

java-collections-maps-3/src/test/java/com/baeldung/map/keysetValuesEntrySet/KeySetExampleUnitTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.map.keysetValuesEntrySet;
+
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class KeySetExampleUnitTest {
+
+    @Test
+    public void givenHashMap_whenKeySetApplied_thenShouldReturnSetOfKeys() {
+        Map<String, Integer> map = new HashMap<>();
+        map.put("one", 1);
+        map.put("two", 2);
+
+        Set<String> actualValues = map.keySet();
+
+        assertEquals(2, actualValues.size());
+        assertTrue(actualValues.contains("one"));
+        assertTrue(actualValues.contains("two"));
+    }
+
+}

java-collections-maps-3/src/test/java/com/baeldung/map/keysetValuesEntrySet/ValuesExampleUnitTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.map.keysetValuesEntrySet;
+
+import org.junit.Test;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class ValuesExampleUnitTest {
+
+    @Test
+    public void givenHashMap_whenValuesApplied_thenShouldReturnCollectionOfValues() {
+        Map<String, Integer> map = new HashMap<>();
+        map.put("one", 1);
+        map.put("two", 2);
+
+        Collection<Integer> actualValues = map.values();
+
+        assertEquals(2, actualValues.size());
+        assertTrue(actualValues.contains(1));
+        assertTrue(actualValues.contains(2));
+    }
+
+}