📍Use lombok, reformat, and optimize the code (#1560)

* Use lombok, reformat, and optimize the code

* Fix merge conflicts and some sonar issues

Co-authored-by: va1m <va1m@email.com>

visitor/README.md

@@ -121,10 +121,9 @@ public class Soldier extends Unit {
 Here are then some concrete visitors.
 
 ```java
+@Slf4j
 public class CommanderVisitor implements UnitVisitor {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(CommanderVisitor.class);
-
   @Override
   public void visitSoldier(Soldier soldier) {
     // Do nothing
@@ -141,10 +140,9 @@ public class CommanderVisitor implements UnitVisitor {
   }
 }
 
+@Slf4j
 public class SergeantVisitor implements UnitVisitor {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(SergeantVisitor.class);
-
   @Override
   public void visitSoldier(Soldier soldier) {
     // Do nothing
@@ -161,10 +159,9 @@ public class SergeantVisitor implements UnitVisitor {
   }
 }
 
+@Slf4j
 public class SoldierVisitor implements UnitVisitor {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(SoldierVisitor.class);
-
   @Override
   public void visitSoldier(Soldier soldier) {
     LOGGER.info("Greetings {}", soldier);