BAEL #4987 - Java Constructors vs Static Factory Methods (#4987)

* Initial Commit

* Update User.java

* Update UserUnitTest.java

* Update User.java - UserUnitTest.java

* Update User.java

core-java/src/main/java/com/baeldung/constructorsstaticfactorymethods/entities/User.java

@@ -8,7 +8,7 @@ import java.util.logging.SimpleFormatter;
 
 public class User {
 
-    private static User instance = null;
+    private static volatile User instance = null;
     private static final Logger LOGGER = Logger.getLogger(User.class.getName());
     private final String name;
     private final String email;