📍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>

reactor/src/main/java/com/iluwatar/reactor/app/AppClient.java

@@ -35,17 +35,15 @@ import java.net.UnknownHostException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Represents the clients of Reactor pattern. Multiple clients are run concurrently and send logging
  * requests to Reactor.
  */
+@Slf4j
 public class AppClient {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(AppClient.class);
-
   private final ExecutorService service = Executors.newFixedThreadPool(4);
 
   /**

reactor/src/main/java/com/iluwatar/reactor/app/LoggingHandler.java

@@ -28,17 +28,15 @@ import com.iluwatar.reactor.framework.ChannelHandler;
 import com.iluwatar.reactor.framework.NioDatagramChannel.DatagramPacket;
 import java.nio.ByteBuffer;
 import java.nio.channels.SelectionKey;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Logging server application logic. It logs the incoming requests on standard console and returns a
  * canned acknowledgement back to the remote peer.
  */
+@Slf4j
 public class LoggingHandler implements ChannelHandler {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(LoggingHandler.class);
-
   private static final byte[] ACK = "Data logged successfully".getBytes();
 
   /**

reactor/src/main/java/com/iluwatar/reactor/framework/NioDatagramChannel.java

@@ -30,16 +30,14 @@ import java.net.SocketAddress;
 import java.nio.ByteBuffer;
 import java.nio.channels.DatagramChannel;
 import java.nio.channels.SelectionKey;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * A wrapper over {@link DatagramChannel} which can read and write data on a DatagramChannel.
  */
+@Slf4j
 public class NioDatagramChannel extends AbstractNioChannel {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(NioDatagramChannel.class);
-
   private final int port;
 
   /**

reactor/src/main/java/com/iluwatar/reactor/framework/NioReactor.java

@@ -32,8 +32,7 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * This class acts as Synchronous Event De-multiplexer and Initiation Dispatcher of Reactor pattern.
@@ -50,10 +49,9 @@ import org.slf4j.LoggerFactory;
  * possible edge cases which are required in a real application. This implementation is meant to
  * demonstrate the fundamental concepts that lie behind Reactor pattern.
  */
+@Slf4j
 public class NioReactor {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(NioReactor.class);
-
   private final Selector selector;
   private final Dispatcher dispatcher;
   /**

reactor/src/main/java/com/iluwatar/reactor/framework/NioServerSocketChannel.java

@@ -30,17 +30,15 @@ import java.nio.ByteBuffer;
 import java.nio.channels.SelectionKey;
 import java.nio.channels.ServerSocketChannel;
 import java.nio.channels.SocketChannel;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * A wrapper over {@link NioServerSocketChannel} which can read and write data on a {@link
  * SocketChannel}.
  */
+@Slf4j
 public class NioServerSocketChannel extends AbstractNioChannel {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(NioServerSocketChannel.class);
-
   private final int port;
 
   /**

reactor/src/test/java/com/iluwatar/reactor/app/ReactorTest.java

@@ -23,23 +23,20 @@
 
 package com.iluwatar.reactor.app;
 
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
 import com.iluwatar.reactor.framework.SameThreadDispatcher;
 import com.iluwatar.reactor.framework.ThreadPoolDispatcher;
 import java.io.IOException;
+import lombok.extern.slf4j.Slf4j;
 import org.junit.jupiter.api.Test;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertNull;
 
 /**
  * This class tests the Distributed Logging service by starting a Reactor and then sending it
  * concurrent logging requests using multiple clients.
  */
-public class ReactorTest {
-
-  private static final Logger LOGGER = LoggerFactory.getLogger(ReactorTest.class);
+@Slf4j
+class ReactorTest {
 
   /**
    * Test the application using pooled thread dispatcher.
@@ -48,7 +45,7 @@ public class ReactorTest {
    * @throws InterruptedException if interrupted while stopping the application.
    */
   @Test
-  public void testAppUsingThreadPoolDispatcher() throws IOException, InterruptedException {
+  void testAppUsingThreadPoolDispatcher() throws IOException, InterruptedException {
     LOGGER.info("testAppUsingThreadPoolDispatcher start");
     var app = new App(new ThreadPoolDispatcher(2));
     app.start();
@@ -80,7 +77,7 @@ public class ReactorTest {
    * @throws InterruptedException if interrupted while stopping the application.
    */
   @Test
-  public void testAppUsingSameThreadDispatcher() throws IOException, InterruptedException {
+  void testAppUsingSameThreadDispatcher() throws IOException, InterruptedException {
     LOGGER.info("testAppUsingSameThreadDispatcher start");
     var app = new App(new SameThreadDispatcher());
     app.start();