BAEL-7178: StringUtils.isBlank() vs String.isEmpty() (#15213)

* adding first test cases

* final code

core-java-modules/core-java-string-operations-7/src/test/java/com/baeldung/isemptyvsisblank/StringIsEmptyVsIsBlankUnitTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.isemptyvsisblank;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class StringIsEmptyVsIsBlankUnitTest {
+
+    @Test
+    public void givenString_whenCallIsEmpty_thenReturnCorrectValues() {
+        assertFalse("Example text".isEmpty());
+        assertTrue("".isEmpty());
+        assertFalse("  ".isEmpty());
+        assertFalse("\t\n\r\f".isEmpty());
+    }
+
+    @Test
+    public void givenString_whenCallStringIsBlank_thenReturnCorrectValues() {
+        assertFalse("Example text".isBlank());
+        assertTrue("".isBlank());
+        assertTrue("  ".isBlank());
+        assertTrue("\t\n\r\f ".isBlank());
+    }
+}