📍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>

thread-pool/src/main/java/com/iluwatar/threadpool/App.java

@@ -26,8 +26,7 @@ package com.iluwatar.threadpool;
 import java.util.List;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Thread Pool pattern is where a number of threads are created to perform a number of tasks, which
@@ -42,10 +41,9 @@ import org.slf4j.LoggerFactory;
  * ExecutorService} with fixed number of threads (Thread Pool) and use them to execute the {@link
  * Worker}s.
  */
+@Slf4j
 public class App {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
-
   /**
    * Program entry point.
    *

thread-pool/src/main/java/com/iluwatar/threadpool/Worker.java

@@ -23,17 +23,15 @@
 
 package com.iluwatar.threadpool;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Worker implements {@link Runnable} and thus can be executed by {@link
  * java.util.concurrent.ExecutorService}.
  */
+@Slf4j
 public class Worker implements Runnable {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(Worker.class);
-
   private final Task task;
 
   public Worker(final Task task) {