diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/client/KafkaConnectClients.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/client/KafkaConnectClients.java
index c39a53497a..2dd2ed585f 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/client/KafkaConnectClients.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/client/KafkaConnectClients.java
@@ -6,6 +6,10 @@ import java.util.concurrent.ConcurrentHashMap;
 
 public final class KafkaConnectClients {
 
+  private KafkaConnectClients() {
+
+  }
+
   private static final Map<String, KafkaConnectClientApi> CACHE = new ConcurrentHashMap<>();
 
   public static KafkaConnectClientApi withBaseUrl(String basePath) {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/client/RetryingKafkaConnectClient.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/client/RetryingKafkaConnectClient.java
index 39d0741865..9cdca46a3b 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/client/RetryingKafkaConnectClient.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/client/RetryingKafkaConnectClient.java
@@ -20,7 +20,6 @@ import org.springframework.web.reactive.function.client.WebClientResponseExcepti
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.util.retry.Retry;
-import reactor.util.retry.RetryBackoffSpec;
 
 @Slf4j
 public class RetryingKafkaConnectClient extends KafkaConnectClientApi {
@@ -32,7 +31,7 @@ public class RetryingKafkaConnectClient extends KafkaConnectClientApi {
   }
 
   private static Retry conflictCodeRetry() {
-    return RetryBackoffSpec
+    return Retry
         .fixedDelay(MAX_RETRIES, RETRIES_DELAY)
         .filter(e -> e instanceof WebClientResponseException.Conflict)
         .onRetryExhaustedThrow((spec, signal) ->
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/ClustersProperties.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/ClustersProperties.java
index 8befe58efc..cf00c9cd81 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/ClustersProperties.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/ClustersProperties.java
@@ -61,14 +61,14 @@ public class ClustersProperties {
 
   private void validateClusterNames() {
     // if only one cluster provided it is ok not to set name
-    if (clusters.size() == 1 && StringUtils.isEmpty(clusters.get(0).getName())) {
+    if (clusters.size() == 1 && !StringUtils.hasText(clusters.get(0).getName())) {
       clusters.get(0).setName("Default");
       return;
     }
 
     Set<String> clusterNames = new HashSet<>();
     for (Cluster clusterProperties : clusters) {
-      if (StringUtils.isEmpty(clusterProperties.getName())) {
+      if (!StringUtils.hasText(clusterProperties.getName())) {
         throw new IllegalStateException(
             "Application config isn't valid. "
                 + "Cluster names should be provided in case of multiple clusters present");
@@ -79,5 +79,4 @@ public class ClustersProperties {
       }
     }
   }
-
 }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/Config.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/Config.java
index 2b256d6eb0..92174d2a47 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/Config.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/Config.java
@@ -1,6 +1,5 @@
 package com.provectus.kafka.ui.config;
 
-import com.fasterxml.jackson.databind.Module;
 import com.provectus.kafka.ui.model.JmxConnectionInfo;
 import com.provectus.kafka.ui.util.JmxPoolFactory;
 import java.util.Collections;
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/ReadOnlyModeFilter.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/ReadOnlyModeFilter.java
index 41b6cc408f..8a8085cad6 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/ReadOnlyModeFilter.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/ReadOnlyModeFilter.java
@@ -45,7 +45,7 @@ public class ReadOnlyModeFilter implements WebFilter {
             () -> new ClusterNotFoundException(
                 String.format("No cluster for name '%s'", clusterName)));
 
-    if (!kafkaCluster.getReadOnly()) {
+    if (!kafkaCluster.isReadOnly()) {
       return chain.filter(exchange);
     }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/AbstractAuthSecurityConfig.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/AbstractAuthSecurityConfig.java
index 5b835106f0..3d8757cada 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/AbstractAuthSecurityConfig.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/AbstractAuthSecurityConfig.java
@@ -2,7 +2,11 @@ package com.provectus.kafka.ui.config.auth;
 
 abstract class AbstractAuthSecurityConfig {
 
-  public static final String[] AUTH_WHITELIST = {
+  protected AbstractAuthSecurityConfig() {
+
+  }
+
+  protected static final String[] AUTH_WHITELIST = {
       "/css/**",
       "/js/**",
       "/media/**",
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/LdapSecurityConfig.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/LdapSecurityConfig.java
index ebd7e09c24..0d629a8836 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/LdapSecurityConfig.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/LdapSecurityConfig.java
@@ -43,11 +43,11 @@ public class LdapSecurityConfig extends AbstractAuthSecurityConfig {
   public ReactiveAuthenticationManager authenticationManager(BaseLdapPathContextSource contextSource) {
     BindAuthenticator ba = new BindAuthenticator(contextSource);
     if (ldapUserDnPattern != null) {
-      ba.setUserDnPatterns(new String[]{ldapUserDnPattern});
+      ba.setUserDnPatterns(new String[] {ldapUserDnPattern});
     }
     if (userFilterSearchFilter != null) {
       LdapUserSearch userSearch =
-              new FilterBasedLdapUserSearch(userFilterSearchBase, userFilterSearchFilter, contextSource);
+          new FilterBasedLdapUserSearch(userFilterSearchBase, userFilterSearchFilter, contextSource);
       ba.setUserSearch(userSearch);
     }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/OAuthSecurityConfig.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/OAuthSecurityConfig.java
index d2cbda6ece..657cab2644 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/OAuthSecurityConfig.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/config/auth/OAuthSecurityConfig.java
@@ -39,14 +39,14 @@ public class OAuthSecurityConfig extends AbstractAuthSecurityConfig {
         .authenticated();
 
     if (IS_OAUTH2_PRESENT && OAuth2ClasspathGuard.shouldConfigure(this.context)) {
-      OAuth2ClasspathGuard.configure(this.context, http);
+      OAuth2ClasspathGuard.configure(http);
     }
 
     return http.csrf().disable().build();
   }
 
   private static class OAuth2ClasspathGuard {
-    static void configure(ApplicationContext context, ServerHttpSecurity http) {
+    static void configure(ServerHttpSecurity http) {
       http
           .oauth2Login()
           .and()
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/AuthController.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/AuthController.java
index 558b4dcf09..2dbe3593b9 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/AuthController.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/AuthController.java
@@ -15,8 +15,8 @@ import reactor.core.publisher.Mono;
 @Slf4j
 public class AuthController {
 
-  @GetMapping(value = "/auth", produces = { "text/html" })
-  private Mono<byte[]> getAuth(ServerWebExchange exchange) {
+  @GetMapping(value = "/auth", produces = {"text/html"})
+  public Mono<byte[]> getAuth(ServerWebExchange exchange) {
     Mono<CsrfToken> token = exchange.getAttributeOrDefault(CsrfToken.class.getName(), Mono.empty());
     return token
         .map(AuthController::csrfToken)
@@ -30,25 +30,25 @@ public class AuthController {
     String contextPath = exchange.getRequest().getPath().contextPath().value();
     String page =
         "<!DOCTYPE html>\n" + "<html lang=\"en\">\n" + "  <head>\n"
-        + "    <meta charset=\"utf-8\">\n"
-        + "    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1, "
-        + "shrink-to-fit=no\">\n"
-        + "    <meta name=\"description\" content=\"\">\n"
-        + "    <meta name=\"author\" content=\"\">\n"
-        + "    <title>Please sign in</title>\n"
-        + "    <link href=\"https://maxcdn.bootstrapcdn.com/bootstrap/"
-        + "4.0.0-beta/css/bootstrap.min.css\" rel=\"stylesheet\" "
-        + "integrity=\"sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M\" "
-        + "crossorigin=\"anonymous\">\n"
-        + "    <link href=\"https://getbootstrap.com/docs/4.0/examples/signin/signin.css\" "
-        + "rel=\"stylesheet\" crossorigin=\"anonymous\"/>\n"
-        + "  </head>\n"
-        + "  <body>\n"
-        + "     <div class=\"container\">\n"
-        + formLogin(queryParams, contextPath, csrfTokenHtmlInput)
-        + "    </div>\n"
-        + "  </body>\n"
-        + "</html>";
+            + "    <meta charset=\"utf-8\">\n"
+            + "    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1, "
+            + "shrink-to-fit=no\">\n"
+            + "    <meta name=\"description\" content=\"\">\n"
+            + "    <meta name=\"author\" content=\"\">\n"
+            + "    <title>Please sign in</title>\n"
+            + "    <link href=\"https://maxcdn.bootstrapcdn.com/bootstrap/"
+            + "4.0.0-beta/css/bootstrap.min.css\" rel=\"stylesheet\" "
+            + "integrity=\"sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M\" "
+            + "crossorigin=\"anonymous\">\n"
+            + "    <link href=\"https://getbootstrap.com/docs/4.0/examples/signin/signin.css\" "
+            + "rel=\"stylesheet\" crossorigin=\"anonymous\"/>\n"
+            + "  </head>\n"
+            + "  <body>\n"
+            + "     <div class=\"container\">\n"
+            + formLogin(queryParams, contextPath, csrfTokenHtmlInput)
+            + "    </div>\n"
+            + "  </body>\n"
+            + "</html>";
 
     return page.getBytes(Charset.defaultCharset());
   }
@@ -61,21 +61,21 @@ public class AuthController {
     boolean isLogoutSuccess = queryParams.containsKey("logout");
     return
         "      <form class=\"form-signin\" method=\"post\" action=\"" + contextPath + "/auth\">\n"
-        + "        <h2 class=\"form-signin-heading\">Please sign in</h2>\n"
-        + createError(isError)
-        + createLogoutSuccess(isLogoutSuccess)
-        + "        <p>\n"
-        + "          <label for=\"username\" class=\"sr-only\">Username</label>\n"
-        + "          <input type=\"text\" id=\"username\" name=\"username\" class=\"form-control\" "
-        + "placeholder=\"Username\" required autofocus>\n"
-        + "        </p>\n" + "        <p>\n"
-        + "          <label for=\"password\" class=\"sr-only\">Password</label>\n"
-        + "          <input type=\"password\" id=\"password\" name=\"password\" "
-        + "class=\"form-control\" placeholder=\"Password\" required>\n"
-        + "        </p>\n" + csrfTokenHtmlInput
-        + "        <button class=\"btn btn-lg btn-primary btn-block\" "
-        + "type=\"submit\">Sign in</button>\n"
-        + "      </form>\n";
+            + "        <h2 class=\"form-signin-heading\">Please sign in</h2>\n"
+            + createError(isError)
+            + createLogoutSuccess(isLogoutSuccess)
+            + "        <p>\n"
+            + "          <label for=\"username\" class=\"sr-only\">Username</label>\n"
+            + "          <input type=\"text\" id=\"username\" name=\"username\" class=\"form-control\" "
+            + "placeholder=\"Username\" required autofocus>\n"
+            + "        </p>\n" + "        <p>\n"
+            + "          <label for=\"password\" class=\"sr-only\">Password</label>\n"
+            + "          <input type=\"password\" id=\"password\" name=\"password\" "
+            + "class=\"form-control\" placeholder=\"Password\" required>\n"
+            + "        </p>\n" + csrfTokenHtmlInput
+            + "        <button class=\"btn btn-lg btn-primary btn-block\" "
+            + "type=\"submit\">Sign in</button>\n"
+            + "      </form>\n";
   }
 
   private static String csrfToken(CsrfToken token) {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/BrokersController.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/BrokersController.java
index cae7f9fffe..e0e1d5dc78 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/BrokersController.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/BrokersController.java
@@ -25,7 +25,7 @@ public class BrokersController extends AbstractController implements BrokersApi
 
   @Override
   public Mono<ResponseEntity<BrokerMetricsDTO>> getBrokersMetrics(String clusterName, Integer id,
-                                                               ServerWebExchange exchange) {
+                                                                  ServerWebExchange exchange) {
     return brokerService.getBrokerMetrics(getCluster(clusterName), id)
         .map(ResponseEntity::ok)
         .onErrorReturn(ResponseEntity.notFound().build());
@@ -33,14 +33,14 @@ public class BrokersController extends AbstractController implements BrokersApi
 
   @Override
   public Mono<ResponseEntity<Flux<BrokerDTO>>> getBrokers(String clusterName,
-                                                       ServerWebExchange exchange) {
+                                                          ServerWebExchange exchange) {
     return Mono.just(ResponseEntity.ok(brokerService.getBrokers(getCluster(clusterName))));
   }
 
   @Override
   public Mono<ResponseEntity<Flux<BrokersLogdirsDTO>>> getAllBrokersLogdirs(String clusterName,
-                                                                         List<Integer> brokers,
-                                                                         ServerWebExchange exchange
+                                                                            List<Integer> brokers,
+                                                                            ServerWebExchange exchange
   ) {
     return Mono.just(ResponseEntity.ok(
         brokerService.getAllBrokersLogdirs(getCluster(clusterName), brokers)));
@@ -48,7 +48,7 @@ public class BrokersController extends AbstractController implements BrokersApi
 
   @Override
   public Mono<ResponseEntity<Flux<BrokerConfigDTO>>> getBrokerConfig(String clusterName, Integer id,
-                                                                  ServerWebExchange exchange) {
+                                                                     ServerWebExchange exchange) {
     return Mono.just(ResponseEntity.ok(
         brokerService.getBrokerConfig(getCluster(clusterName), id)));
   }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ClustersController.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ClustersController.java
index c06947308b..38b2b1dc65 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ClustersController.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ClustersController.java
@@ -21,7 +21,7 @@ public class ClustersController extends AbstractController implements ClustersAp
 
   @Override
   public Mono<ResponseEntity<ClusterMetricsDTO>> getClusterMetrics(String clusterName,
-                                                                ServerWebExchange exchange) {
+                                                                   ServerWebExchange exchange) {
     return clusterService.getClusterMetrics(getCluster(clusterName))
         .map(ResponseEntity::ok)
         .onErrorReturn(ResponseEntity.notFound().build());
@@ -29,7 +29,7 @@ public class ClustersController extends AbstractController implements ClustersAp
 
   @Override
   public Mono<ResponseEntity<ClusterStatsDTO>> getClusterStats(String clusterName,
-                                                            ServerWebExchange exchange) {
+                                                               ServerWebExchange exchange) {
     return clusterService.getClusterStats(getCluster(clusterName))
         .map(ResponseEntity::ok)
         .onErrorReturn(ResponseEntity.notFound().build());
@@ -42,7 +42,7 @@ public class ClustersController extends AbstractController implements ClustersAp
 
   @Override
   public Mono<ResponseEntity<ClusterDTO>> updateClusterInfo(String clusterName,
-                                                         ServerWebExchange exchange) {
+                                                            ServerWebExchange exchange) {
     return clusterService.updateCluster(getCluster(clusterName)).map(ResponseEntity::ok);
   }
 }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ConsumerGroupsController.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ConsumerGroupsController.java
index 28ce1bbada..c0d4d0296c 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ConsumerGroupsController.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/ConsumerGroupsController.java
@@ -56,7 +56,7 @@ public class ConsumerGroupsController extends AbstractController implements Cons
 
   @Override
   public Mono<ResponseEntity<Flux<ConsumerGroupDTO>>> getConsumerGroups(String clusterName,
-                                                                     ServerWebExchange exchange) {
+                                                                        ServerWebExchange exchange) {
     return consumerGroupService.getAllConsumerGroups(getCluster(clusterName))
         .map(Flux::fromIterable)
         .map(f -> f.map(ConsumerGroupMapper::toDto))
@@ -96,7 +96,7 @@ public class ConsumerGroupsController extends AbstractController implements Cons
   }
 
   private ConsumerGroupsPageResponseDTO convertPage(ConsumerGroupService.ConsumerGroupsPage
-                                                    consumerGroupConsumerGroupsPage) {
+                                                        consumerGroupConsumerGroupsPage) {
     return new ConsumerGroupsPageResponseDTO()
         .pageCount(consumerGroupConsumerGroupsPage.getTotalPages())
         .consumerGroups(consumerGroupConsumerGroupsPage.getConsumerGroups()
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KafkaConnectController.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KafkaConnectController.java
index 9abc3884f9..8011fe8e5f 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KafkaConnectController.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KafkaConnectController.java
@@ -28,7 +28,7 @@ public class KafkaConnectController extends AbstractController implements KafkaC
 
   @Override
   public Mono<ResponseEntity<Flux<ConnectDTO>>> getConnects(String clusterName,
-                                                         ServerWebExchange exchange) {
+                                                            ServerWebExchange exchange) {
     return kafkaConnectService.getConnects(getCluster(clusterName)).map(ResponseEntity::ok);
   }
 
@@ -41,16 +41,16 @@ public class KafkaConnectController extends AbstractController implements KafkaC
 
   @Override
   public Mono<ResponseEntity<ConnectorDTO>> createConnector(String clusterName, String connectName,
-                                                         @Valid Mono<NewConnectorDTO> connector,
-                                                         ServerWebExchange exchange) {
+                                                            @Valid Mono<NewConnectorDTO> connector,
+                                                            ServerWebExchange exchange) {
     return kafkaConnectService.createConnector(getCluster(clusterName), connectName, connector)
         .map(ResponseEntity::ok);
   }
 
   @Override
   public Mono<ResponseEntity<ConnectorDTO>> getConnector(String clusterName, String connectName,
-                                                      String connectorName,
-                                                      ServerWebExchange exchange) {
+                                                         String connectorName,
+                                                         ServerWebExchange exchange) {
     return kafkaConnectService.getConnector(getCluster(clusterName), connectName, connectorName)
         .map(ResponseEntity::ok);
   }
@@ -87,9 +87,9 @@ public class KafkaConnectController extends AbstractController implements KafkaC
   @Override
   public Mono<ResponseEntity<ConnectorDTO>> setConnectorConfig(String clusterName,
                                                                String connectName,
-                                                            String connectorName,
-                                                            @Valid Mono<Object> requestBody,
-                                                            ServerWebExchange exchange) {
+                                                               String connectorName,
+                                                               @Valid Mono<Object> requestBody,
+                                                               ServerWebExchange exchange) {
     return kafkaConnectService
         .setConnectorConfig(getCluster(clusterName), connectName, connectorName, requestBody)
         .map(ResponseEntity::ok);
@@ -135,8 +135,8 @@ public class KafkaConnectController extends AbstractController implements KafkaC
   @Override
   public Mono<ResponseEntity<ConnectorPluginConfigValidationResponseDTO>>
       validateConnectorPluginConfig(
-        String clusterName, String connectName, String pluginName, @Valid Mono<Object> requestBody,
-        ServerWebExchange exchange) {
+      String clusterName, String connectName, String pluginName, @Valid Mono<Object> requestBody,
+      ServerWebExchange exchange) {
     return kafkaConnectService
         .validateConnectorPluginConfig(
             getCluster(clusterName), connectName, pluginName, requestBody)
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KsqlController.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KsqlController.java
index 152113d29d..face9206bc 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KsqlController.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/KsqlController.java
@@ -27,9 +27,9 @@ public class KsqlController extends AbstractController implements KsqlApi {
 
   @Override
   public Mono<ResponseEntity<KsqlCommandResponseDTO>> executeKsqlCommand(String clusterName,
-                                                                      Mono<KsqlCommandDTO>
-                                                                          ksqlCommand,
-                                                                      ServerWebExchange exchange) {
+                                                                         Mono<KsqlCommandDTO>
+                                                                             ksqlCommand,
+                                                                         ServerWebExchange exchange) {
     return ksqlService.executeKsqlCommand(getCluster(clusterName), ksqlCommand)
         .map(ResponseEntity::ok);
   }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/StaticController.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/StaticController.java
index c00500fdea..c2d6a10b36 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/StaticController.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/StaticController.java
@@ -1,13 +1,11 @@
 package com.provectus.kafka.ui.controller;
 
 import com.provectus.kafka.ui.util.ResourceUtil;
-import java.util.Optional;
 import java.util.concurrent.atomic.AtomicReference;
 import lombok.RequiredArgsConstructor;
 import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Value;
-import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.core.io.Resource;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -24,7 +22,7 @@ public class StaticController {
   private Resource indexFile;
   private final AtomicReference<String> renderedIndexFile = new AtomicReference<>();
 
-  @GetMapping(value = "/index.html", produces = { "text/html" })
+  @GetMapping(value = "/index.html", produces = {"text/html"})
   public Mono<ResponseEntity<String>> getIndex(ServerWebExchange exchange) {
     return Mono.just(ResponseEntity.ok(getRenderedIndexFile(exchange)));
   }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/TopicsController.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/TopicsController.java
index 6d58f5eaf6..b05d19d853 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/TopicsController.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/controller/TopicsController.java
@@ -43,7 +43,7 @@ public class TopicsController extends AbstractController implements TopicsApi {
   public Mono<ResponseEntity<TopicDTO>> recreateTopic(String clusterName,
                                                       String topicName, ServerWebExchange serverWebExchange) {
     return topicsService.recreateTopic(getCluster(clusterName), topicName)
-            .map(s -> new ResponseEntity<>(s, HttpStatus.CREATED));
+        .map(s -> new ResponseEntity<>(s, HttpStatus.CREATED));
   }
 
   @Override
@@ -70,12 +70,12 @@ public class TopicsController extends AbstractController implements TopicsApi {
 
   @Override
   public Mono<ResponseEntity<TopicsResponseDTO>> getTopics(String clusterName, @Valid Integer page,
-                                                        @Valid Integer perPage,
-                                                        @Valid Boolean showInternal,
-                                                        @Valid String search,
-                                                        @Valid TopicColumnsToSortDTO orderBy,
-                                                        @Valid SortOrderDTO sortOrder,
-                                                        ServerWebExchange exchange) {
+                                                           @Valid Integer perPage,
+                                                           @Valid Boolean showInternal,
+                                                           @Valid String search,
+                                                           @Valid TopicColumnsToSortDTO orderBy,
+                                                           @Valid SortOrderDTO sortOrder,
+                                                           ServerWebExchange exchange) {
     return topicsService
         .getTopics(
             getCluster(clusterName),
@@ -101,10 +101,9 @@ public class TopicsController extends AbstractController implements TopicsApi {
       String clusterName, String topicName,
       Mono<PartitionsIncreaseDTO> partitionsIncrease,
       ServerWebExchange exchange) {
-    return partitionsIncrease.flatMap(
-        partitions ->
-            topicsService.increaseTopicPartitions(getCluster(clusterName), topicName, partitions))
-        .map(ResponseEntity::ok);
+    return partitionsIncrease.flatMap(partitions ->
+            topicsService.increaseTopicPartitions(getCluster(clusterName), topicName, partitions)
+        ).map(ResponseEntity::ok);
   }
 
   @Override
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/AbstractEmitter.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/AbstractEmitter.java
index 76e46138b6..9b7905fe3e 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/AbstractEmitter.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/AbstractEmitter.java
@@ -19,7 +19,7 @@ public abstract class AbstractEmitter {
   private final RecordSerDe recordDeserializer;
   private final ConsumingStats consumingStats = new ConsumingStats();
 
-  public AbstractEmitter(RecordSerDe recordDeserializer) {
+  protected AbstractEmitter(RecordSerDe recordDeserializer) {
     this.recordDeserializer = recordDeserializer;
   }
 
@@ -33,7 +33,7 @@ public abstract class AbstractEmitter {
   }
 
   protected FluxSink<TopicMessageEventDTO> sendMessage(FluxSink<TopicMessageEventDTO> sink,
-                             ConsumerRecord<Bytes, Bytes> msg) {
+                                                       ConsumerRecord<Bytes, Bytes> msg) {
     final TopicMessageDTO topicMessage = ClusterUtil.mapToTopicMessage(msg, recordDeserializer);
     return sink.next(
         new TopicMessageEventDTO()
@@ -45,8 +45,8 @@ public abstract class AbstractEmitter {
   protected void sendPhase(FluxSink<TopicMessageEventDTO> sink, String name) {
     sink.next(
         new TopicMessageEventDTO()
-          .type(TopicMessageEventDTO.TypeEnum.PHASE)
-          .phase(new TopicMessagePhaseDTO().name(name))
+            .type(TopicMessageEventDTO.TypeEnum.PHASE)
+            .phase(new TopicMessagePhaseDTO().name(name))
     );
   }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/BackwardRecordEmitter.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/BackwardRecordEmitter.java
index f21c1533d0..302cb9879b 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/BackwardRecordEmitter.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/BackwardRecordEmitter.java
@@ -87,7 +87,7 @@ public class BackwardRecordEmitter
 
               // This is workaround for case when partition begin offset is less than
               // real minimal offset, usually appear in compcated topics
-              if (records.count() > 0  && partitionRecords.isEmpty()) {
+              if (records.count() > 0 && partitionRecords.isEmpty()) {
                 waitingOffsets.markPolled(entry.getKey().partition());
               }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/ConsumingStats.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/ConsumingStats.java
index 359d49386a..830eb87320 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/ConsumingStats.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/ConsumingStats.java
@@ -15,15 +15,15 @@ class ConsumingStats {
   private long elapsed = 0;
 
   void sendConsumingEvt(FluxSink<TopicMessageEventDTO> sink,
-                               ConsumerRecords<Bytes, Bytes> polledRecords,
-                               long elapsed) {
-    for (ConsumerRecord<Bytes, Bytes> record : polledRecords) {
-      for (Header header : record.headers()) {
+                        ConsumerRecords<Bytes, Bytes> polledRecords,
+                        long elapsed) {
+    for (ConsumerRecord<Bytes, Bytes> rec : polledRecords) {
+      for (Header header : rec.headers()) {
         bytes +=
             (header.key() != null ? header.key().getBytes().length : 0L)
                 + (header.value() != null ? header.value().length : 0L);
       }
-      bytes += record.serializedKeySize() + record.serializedValueSize();
+      bytes += rec.serializedKeySize() + rec.serializedValueSize();
     }
     this.records += polledRecords.count();
     this.elapsed += elapsed;
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/MessageFilters.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/MessageFilters.java
index ee14f1b66d..446f166bfe 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/MessageFilters.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/emitter/MessageFilters.java
@@ -18,6 +18,9 @@ public class MessageFilters {
 
   private static GroovyScriptEngineImpl GROOVY_ENGINE;
 
+  private MessageFilters() {
+  }
+
   public static Predicate<TopicMessageDTO> createMsgFilter(String query, MessageFilterTypeDTO type) {
     switch (type) {
       case STRING_CONTAINS:
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/CustomBaseException.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/CustomBaseException.java
index 9b43e699b7..550243b82b 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/CustomBaseException.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/CustomBaseException.java
@@ -19,7 +19,7 @@ public abstract class CustomBaseException extends RuntimeException {
   }
 
   protected CustomBaseException(String message, Throwable cause, boolean enableSuppression,
-                             boolean writableStackTrace) {
+                                boolean writableStackTrace) {
     super(message, cause, enableSuppression, writableStackTrace);
   }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/ErrorCode.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/ErrorCode.java
index d6ed8b8a93..2c801d3d05 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/ErrorCode.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/ErrorCode.java
@@ -34,7 +34,7 @@ public enum ErrorCode {
     for (ErrorCode value : ErrorCode.values()) {
       if (!codes.add(value.code())) {
         LoggerFactory.getLogger(ErrorCode.class)
-                .warn("Multiple {} values refer to code {}", ErrorCode.class, value.code);
+            .warn("Multiple {} values refer to code {}", ErrorCode.class, value.code);
       }
     }
   }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/SchemaTypeIsNotSupportedException.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/SchemaTypeIsNotSupportedException.java
deleted file mode 100644
index eabaaf97e5..0000000000
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/SchemaTypeIsNotSupportedException.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package com.provectus.kafka.ui.exception;
-
-public class SchemaTypeIsNotSupportedException extends UnprocessableEntityException {
-
-  private static final String REQUIRED_SCHEMA_REGISTRY_VERSION = "5.5.0";
-
-  public SchemaTypeIsNotSupportedException() {
-    super(String.format("Current version of Schema Registry does "
-            + "not support provided schema type,"
-            + " version %s or later is required here.", REQUIRED_SCHEMA_REGISTRY_VERSION));
-  }
-}
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/SchemaTypeNotSupportedException.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/SchemaTypeNotSupportedException.java
new file mode 100644
index 0000000000..9fd7a06af8
--- /dev/null
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/SchemaTypeNotSupportedException.java
@@ -0,0 +1,12 @@
+package com.provectus.kafka.ui.exception;
+
+public class SchemaTypeNotSupportedException extends UnprocessableEntityException {
+
+  private static final String REQUIRED_SCHEMA_REGISTRY_VERSION = "5.5.0";
+
+  public SchemaTypeNotSupportedException() {
+    super(String.format("Current version of Schema Registry does "
+        + "not support provided schema type,"
+        + " version %s or later is required here.", REQUIRED_SCHEMA_REGISTRY_VERSION));
+  }
+}
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/TopicRecreationException.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/TopicRecreationException.java
index 0eca1fb62d..0425ed1157 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/TopicRecreationException.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/exception/TopicRecreationException.java
@@ -8,6 +8,6 @@ public class TopicRecreationException extends CustomBaseException {
 
   public TopicRecreationException(String topicName, int seconds) {
     super(String.format("Can't create topic '%s' in %d seconds: "
-                + "topic deletion is still in progress", topicName, seconds));
+        + "topic deletion is still in progress", topicName, seconds));
   }
 }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/mapper/ConsumerGroupMapper.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/mapper/ConsumerGroupMapper.java
index 192058449f..d04484b381 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/mapper/ConsumerGroupMapper.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/mapper/ConsumerGroupMapper.java
@@ -17,6 +17,9 @@ import org.apache.kafka.common.TopicPartition;
 
 public class ConsumerGroupMapper {
 
+  private ConsumerGroupMapper() {
+  }
+
   public static ConsumerGroupDTO toDto(InternalConsumerGroup c) {
     return convertToConsumerGroup(c, new ConsumerGroupDTO());
   }
@@ -47,7 +50,7 @@ public class ConsumerGroupMapper {
       for (TopicPartition topicPartition : member.getAssignment()) {
         final ConsumerGroupTopicPartitionDTO partition = partitionMap.computeIfAbsent(
             topicPartition,
-            (tp) -> new ConsumerGroupTopicPartitionDTO()
+            tp -> new ConsumerGroupTopicPartitionDTO()
                 .topic(tp.topic())
                 .partition(tp.partition())
         );
@@ -99,12 +102,18 @@ public class ConsumerGroupMapper {
   private static ConsumerGroupStateDTO mapConsumerGroupState(
       org.apache.kafka.common.ConsumerGroupState state) {
     switch (state) {
-      case DEAD: return ConsumerGroupStateDTO.DEAD;
-      case EMPTY: return ConsumerGroupStateDTO.EMPTY;
-      case STABLE: return ConsumerGroupStateDTO.STABLE;
-      case PREPARING_REBALANCE: return ConsumerGroupStateDTO.PREPARING_REBALANCE;
-      case COMPLETING_REBALANCE: return ConsumerGroupStateDTO.COMPLETING_REBALANCE;
-      default: return ConsumerGroupStateDTO.UNKNOWN;
+      case DEAD:
+        return ConsumerGroupStateDTO.DEAD;
+      case EMPTY:
+        return ConsumerGroupStateDTO.EMPTY;
+      case STABLE:
+        return ConsumerGroupStateDTO.STABLE;
+      case PREPARING_REBALANCE:
+        return ConsumerGroupStateDTO.PREPARING_REBALANCE;
+      case COMPLETING_REBALANCE:
+        return ConsumerGroupStateDTO.COMPLETING_REBALANCE;
+      default:
+        return ConsumerGroupStateDTO.UNKNOWN;
     }
   }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/mapper/DescribeLogDirsMapper.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/mapper/DescribeLogDirsMapper.java
index 3b029fa2d3..c7e66d0f45 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/mapper/DescribeLogDirsMapper.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/mapper/DescribeLogDirsMapper.java
@@ -25,7 +25,7 @@ public class DescribeLogDirsMapper {
   }
 
   private BrokersLogdirsDTO toBrokerLogDirs(Integer broker, String dirName,
-                                         DescribeLogDirsResponse.LogDirInfo logDirInfo) {
+                                            DescribeLogDirsResponse.LogDirInfo logDirInfo) {
     BrokersLogdirsDTO result = new BrokersLogdirsDTO();
     result.setName(dirName);
     if (logDirInfo.error != null) {
@@ -40,8 +40,8 @@ public class DescribeLogDirsMapper {
   }
 
   private BrokerTopicLogdirsDTO toTopicLogDirs(Integer broker, String name,
-                                            List<Map.Entry<TopicPartition,
-                                            DescribeLogDirsResponse.ReplicaInfo>> partitions) {
+                                               List<Map.Entry<TopicPartition,
+                                                   DescribeLogDirsResponse.ReplicaInfo>> partitions) {
     BrokerTopicLogdirsDTO topic = new BrokerTopicLogdirsDTO();
     topic.setName(name);
     topic.setPartitions(
@@ -53,8 +53,8 @@ public class DescribeLogDirsMapper {
   }
 
   private BrokerTopicPartitionLogdirDTO topicPartitionLogDir(Integer broker, Integer partition,
-                                                          DescribeLogDirsResponse.ReplicaInfo
-                                                              replicaInfo) {
+                                                             DescribeLogDirsResponse.ReplicaInfo
+                                                                 replicaInfo) {
     BrokerTopicPartitionLogdirDTO logDir = new BrokerTopicPartitionLogdirDTO();
     logDir.setBroker(broker);
     logDir.setPartition(partition);
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/CleanupPolicy.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/CleanupPolicy.java
index 3f7cdfca4c..809dffa4c1 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/CleanupPolicy.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/CleanupPolicy.java
@@ -1,6 +1,5 @@
 package com.provectus.kafka.ui.model;
 
-import com.provectus.kafka.ui.exception.IllegalEntityStateException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -11,24 +10,24 @@ public enum CleanupPolicy {
   COMPACT_DELETE(Arrays.asList("compact,delete", "delete,compact")),
   UNKNOWN("unknown");
 
-  private final List<String> cleanUpPolicy;
+  private final List<String> policies;
 
-  CleanupPolicy(String cleanUpPolicy) {
-    this(Collections.singletonList(cleanUpPolicy));
+  CleanupPolicy(String policy) {
+    this(Collections.singletonList(policy));
   }
 
-  CleanupPolicy(List<String> cleanUpPolicy) {
-    this.cleanUpPolicy = cleanUpPolicy;
+  CleanupPolicy(List<String> policies) {
+    this.policies = policies;
   }
 
-  public String getCleanUpPolicy() {
-    return cleanUpPolicy.get(0);
+  public String getPolicy() {
+    return policies.get(0);
   }
 
   public static CleanupPolicy fromString(String string) {
     return Arrays.stream(CleanupPolicy.values())
         .filter(v ->
-            v.cleanUpPolicy.stream().anyMatch(
+            v.policies.stream().anyMatch(
                 s -> s.equals(string.replace(" ", "")
                 )
             )
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalClusterMetrics.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalClusterMetrics.java
index b46b756e9c..756a2740c6 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalClusterMetrics.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalClusterMetrics.java
@@ -38,7 +38,7 @@ public class InternalClusterMetrics {
 
   // zk stats
   @Deprecated //use 'zookeeperStatus' field with enum type instead
-  private final int zooKeeperStatus;
+  private final int zooKeeperStatusEnum;
   private final ServerStatusDTO zookeeperStatus;
   private final Throwable lastZookeeperException;
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalClusterState.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalClusterState.java
index 8626047c4c..3fe6ebe3dc 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalClusterState.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalClusterState.java
@@ -67,7 +67,7 @@ public class InternalClusterState {
     inSyncReplicasCount = partitionsStats.getInSyncReplicasCount();
     outOfSyncReplicasCount = partitionsStats.getOutOfSyncReplicasCount();
     underReplicatedPartitionCount = partitionsStats.getUnderReplicatedPartitionCount();
-    readOnly = cluster.getReadOnly();
+    readOnly = cluster.isReadOnly();
   }
 
 }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalConsumerGroup.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalConsumerGroup.java
index 2a16bea48a..df5df2ef1f 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalConsumerGroup.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalConsumerGroup.java
@@ -36,7 +36,7 @@ public class InternalConsumerGroup {
   }
 
   public static InternalConsumerGroup create(
-      ConsumerGroupDescription description, 
+      ConsumerGroupDescription description,
       Map<TopicPartition, Long> groupOffsets,
       Map<TopicPartition, Long> topicEndOffsets) {
     var builder = InternalConsumerGroup.builder();
@@ -65,21 +65,21 @@ public class InternalConsumerGroup {
 
   // removes data for all partitions that are not fit filter
   public InternalConsumerGroup retainDataForPartitions(Predicate<TopicPartition> partitionsFilter) {
-    var offsets = getOffsets().entrySet().stream()
+    var offsetsMap = getOffsets().entrySet().stream()
         .filter(e -> partitionsFilter.test(e.getKey()))
         .collect(Collectors.toMap(
             Map.Entry::getKey,
             Map.Entry::getValue
         ));
 
-    var members = getMembers().stream()
+    var nonEmptyMembers = getMembers().stream()
         .map(m -> filterConsumerMemberTopic(m, partitionsFilter))
         .filter(m -> !m.getAssignment().isEmpty())
         .collect(Collectors.toList());
 
     return toBuilder()
-        .offsets(offsets)
-        .members(members)
+        .offsets(offsetsMap)
+        .members(nonEmptyMembers)
         .build();
   }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalSchemaRegistry.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalSchemaRegistry.java
index 0606579d78..5516c05a6d 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalSchemaRegistry.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/InternalSchemaRegistry.java
@@ -12,7 +12,7 @@ public class InternalSchemaRegistry {
   private final List<String> url;
 
   public String getFirstUrl() {
-    return url != null  && !url.isEmpty() ? url.iterator().next() : null;
+    return url != null && !url.isEmpty() ? url.iterator().next() : null;
   }
 
 }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/KafkaCluster.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/KafkaCluster.java
index 56bbabdf89..1a97fe13a0 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/KafkaCluster.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/KafkaCluster.java
@@ -30,6 +30,6 @@ public class KafkaCluster {
   private final String protobufMessageName;
   private final Map<String, String> protobufMessageNameByTopic;
   private final Properties properties;
-  private final Boolean readOnly;
-  private final Boolean disableLogDirsCollection;
+  private final boolean readOnly;
+  private final boolean disableLogDirsCollection;
 }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/schemaregistry/InternalNewSchema.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/schemaregistry/InternalNewSchema.java
index 92fe3f5b9e..ba5721724a 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/schemaregistry/InternalNewSchema.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/model/schemaregistry/InternalNewSchema.java
@@ -2,7 +2,6 @@ package com.provectus.kafka.ui.model.schemaregistry;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.provectus.kafka.ui.model.SchemaTypeDTO;
-import com.provectus.kafka.ui.model.SchemaTypeDTO;
 import lombok.Data;
 
 @Data
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/ProtobufFileRecordSerDe.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/ProtobufFileRecordSerDe.java
index 2aa93bfa4d..7553535999 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/ProtobufFileRecordSerDe.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/ProtobufFileRecordSerDe.java
@@ -87,8 +87,8 @@ public class ProtobufFileRecordSerDe implements RecordSerDe {
   @SneakyThrows
   private String parse(byte[] value, Descriptor descriptor) {
     DynamicMessage protoMsg = DynamicMessage.parseFrom(
-            descriptor,
-            new ByteArrayInputStream(value)
+        descriptor,
+        new ByteArrayInputStream(value)
     );
     byte[] jsonFromProto = ProtobufSchemaUtils.toJson(protoMsg);
     return new String(jsonFromProto);
@@ -121,8 +121,8 @@ public class ProtobufFileRecordSerDe implements RecordSerDe {
   public TopicMessageSchemaDTO getTopicSchema(String topic) {
 
     final JsonSchema jsonSchema = schemaConverter.convert(
-            protobufSchemaPath.toUri(),
-            getDescriptor(topic)
+        protobufSchemaPath.toUri(),
+        getDescriptor(topic)
     );
     final MessageSchemaDTO keySchema = new MessageSchemaDTO()
         .name(protobufSchema.fullName())
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/RecordSerDe.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/RecordSerDe.java
index f3792179e0..af5a188e3d 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/RecordSerDe.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/RecordSerDe.java
@@ -14,12 +14,18 @@ public interface RecordSerDe {
   @Value
   @Builder
   class DeserializedKeyValue {
-    @Nullable String key;
-    @Nullable String value;
-    @Nullable MessageFormat keyFormat;
-    @Nullable MessageFormat valueFormat;
-    @Nullable String keySchemaId;
-    @Nullable String valueSchemaId;
+    @Nullable
+    String key;
+    @Nullable
+    String value;
+    @Nullable
+    MessageFormat keyFormat;
+    @Nullable
+    MessageFormat valueFormat;
+    @Nullable
+    String keySchemaId;
+    @Nullable
+    String valueSchemaId;
   }
 
   DeserializedKeyValue deserialize(ConsumerRecord<Bytes, Bytes> msg);
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/AvroMessageReader.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/AvroMessageReader.java
index fcf5173a27..7f2efbbd64 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/AvroMessageReader.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/AvroMessageReader.java
@@ -6,8 +6,8 @@ import io.confluent.kafka.schemaregistry.avro.AvroSchemaUtils;
 import io.confluent.kafka.schemaregistry.client.SchemaMetadata;
 import io.confluent.kafka.schemaregistry.client.SchemaRegistryClient;
 import io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException;
+import io.confluent.kafka.serializers.AbstractKafkaSchemaSerDeConfig;
 import io.confluent.kafka.serializers.KafkaAvroSerializer;
-import io.confluent.kafka.serializers.KafkaAvroSerializerConfig;
 import java.io.IOException;
 import java.util.Map;
 import org.apache.kafka.common.serialization.Serializer;
@@ -27,8 +27,8 @@ public class AvroMessageReader extends MessageReader<Object> {
     serializer.configure(
         Map.of(
             "schema.registry.url", "wontbeused",
-            KafkaAvroSerializerConfig.AUTO_REGISTER_SCHEMAS, false,
-            KafkaAvroSerializerConfig.USE_LATEST_VERSION, true
+            AbstractKafkaSchemaSerDeConfig.AUTO_REGISTER_SCHEMAS, false,
+            AbstractKafkaSchemaSerDeConfig.USE_LATEST_VERSION, true
         ),
         isKey
     );
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/JsonSchemaMessageReader.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/JsonSchemaMessageReader.java
index 1cecdf7fd5..de56ed462e 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/JsonSchemaMessageReader.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/JsonSchemaMessageReader.java
@@ -10,8 +10,8 @@ import io.confluent.kafka.schemaregistry.client.SchemaMetadata;
 import io.confluent.kafka.schemaregistry.client.SchemaRegistryClient;
 import io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException;
 import io.confluent.kafka.schemaregistry.json.JsonSchema;
+import io.confluent.kafka.serializers.AbstractKafkaSchemaSerDeConfig;
 import io.confluent.kafka.serializers.json.KafkaJsonSchemaSerializer;
-import io.confluent.kafka.serializers.json.KafkaJsonSchemaSerializerConfig;
 import java.io.IOException;
 import java.util.Map;
 import org.apache.kafka.common.serialization.Serializer;
@@ -33,8 +33,8 @@ public class JsonSchemaMessageReader extends MessageReader<JsonNode> {
     serializer.configure(
         Map.of(
             "schema.registry.url", "wontbeused",
-            KafkaJsonSchemaSerializerConfig.AUTO_REGISTER_SCHEMAS, false,
-            KafkaJsonSchemaSerializerConfig.USE_LATEST_VERSION, true
+            AbstractKafkaSchemaSerDeConfig.AUTO_REGISTER_SCHEMAS, false,
+            AbstractKafkaSchemaSerDeConfig.USE_LATEST_VERSION, true
         ),
         isKey
     );
@@ -69,10 +69,10 @@ public class JsonSchemaMessageReader extends MessageReader<JsonNode> {
      * possible in our case. So, we just skip all infer logic and pass schema directly.
      */
     @Override
-    public byte[] serialize(String topic, JsonNode record) {
+    public byte[] serialize(String topic, JsonNode rec) {
       return super.serializeImpl(
-          super.getSubjectName(topic, isKey, record, schema),
-          record,
+          super.getSubjectName(topic, isKey, rec, schema),
+          rec,
           (JsonSchema) schema
       );
     }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/ProtobufMessageReader.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/ProtobufMessageReader.java
index ce3150467c..faa9cde049 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/ProtobufMessageReader.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/ProtobufMessageReader.java
@@ -8,8 +8,8 @@ import io.confluent.kafka.schemaregistry.client.SchemaMetadata;
 import io.confluent.kafka.schemaregistry.client.SchemaRegistryClient;
 import io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException;
 import io.confluent.kafka.schemaregistry.protobuf.ProtobufSchema;
+import io.confluent.kafka.serializers.AbstractKafkaSchemaSerDeConfig;
 import io.confluent.kafka.serializers.protobuf.KafkaProtobufSerializer;
-import io.confluent.kafka.serializers.protobuf.KafkaProtobufSerializerConfig;
 import java.io.IOException;
 import java.util.Map;
 import org.apache.kafka.common.serialization.Serializer;
@@ -28,8 +28,8 @@ public class ProtobufMessageReader extends MessageReader<Message> {
     serializer.configure(
         Map.of(
             "schema.registry.url", "wontbeused",
-            KafkaProtobufSerializerConfig.AUTO_REGISTER_SCHEMAS, false,
-            KafkaProtobufSerializerConfig.USE_LATEST_VERSION, true
+            AbstractKafkaSchemaSerDeConfig.AUTO_REGISTER_SCHEMAS, false,
+            AbstractKafkaSchemaSerDeConfig.USE_LATEST_VERSION, true
         ),
         isKey
     );
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/SchemaRegistryAwareRecordSerDe.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/SchemaRegistryAwareRecordSerDe.java
index ab3c7a0213..4a903598c4 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/SchemaRegistryAwareRecordSerDe.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/serde/schemaregistry/SchemaRegistryAwareRecordSerDe.java
@@ -113,7 +113,7 @@ public class SchemaRegistryAwareRecordSerDe implements RecordSerDe {
                                          DeserializedKeyValueBuilder builder) {
     Optional<Integer> schemaId = extractSchemaIdFromMsg(rec, isKey);
     Optional<MessageFormat> format = schemaId.flatMap(this::getMessageFormatBySchemaId);
-    if (format.isPresent() && schemaRegistryFormatters.containsKey(format.get())) {
+    if (schemaId.isPresent() && format.isPresent() && schemaRegistryFormatters.containsKey(format.get())) {
       var formatter = schemaRegistryFormatters.get(format.get());
       try {
         var deserialized = formatter.format(rec.topic(), isKey ? rec.key().get() : rec.value().get());
@@ -135,12 +135,13 @@ public class SchemaRegistryAwareRecordSerDe implements RecordSerDe {
 
     // fallback
     if (isKey) {
-      builder.key(FALLBACK_FORMATTER.format(rec.topic(), isKey ? rec.key().get() : rec.value().get()));
+      builder.key(FALLBACK_FORMATTER.format(rec.topic(), rec.key().get()));
       builder.keyFormat(FALLBACK_FORMATTER.getFormat());
     } else {
-      builder.value(FALLBACK_FORMATTER.format(rec.topic(), isKey ? rec.key().get() : rec.value().get()));
+      builder.value(FALLBACK_FORMATTER.format(rec.topic(), rec.value().get()));
       builder.valueFormat(FALLBACK_FORMATTER.getFormat());
     }
+
   }
 
   @Override
@@ -202,14 +203,14 @@ public class SchemaRegistryAwareRecordSerDe implements RecordSerDe {
 
     final MessageSchemaDTO keySchema = new MessageSchemaDTO()
         .name(maybeKeySchema.map(
-            (s) -> schemaSubject(topic, true)
+            s -> schemaSubject(topic, true)
         ).orElse("unknown"))
         .source(MessageSchemaDTO.SourceEnum.SCHEMA_REGISTRY)
         .schema(sourceKeySchema);
 
     final MessageSchemaDTO valueSchema = new MessageSchemaDTO()
         .name(maybeValueSchema.map(
-            (s) -> schemaSubject(topic, false)
+            s -> schemaSubject(topic, false)
         ).orElse("unknown"))
         .source(MessageSchemaDTO.SourceEnum.SCHEMA_REGISTRY)
         .schema(sourceValueSchema);
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/BrokerService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/BrokerService.java
index 0f5085eb33..b5b3aa1680 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/BrokerService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/BrokerService.java
@@ -105,7 +105,7 @@ public class BrokerService {
     Map<TopicPartitionReplica, String> req = Map.of(
         new TopicPartitionReplica(b.getTopic(), b.getPartition(), broker),
         b.getLogDir());
-    return  admin.alterReplicaLogDirs(req)
+    return admin.alterReplicaLogDirs(req)
         .onErrorResume(UnknownTopicOrPartitionException.class,
             e -> Mono.error(new TopicOrPartitionNotFoundException()))
         .onErrorResume(LogDirNotFoundException.class,
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ConsumerGroupService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ConsumerGroupService.java
index 790dcd0e61..cba51a921a 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ConsumerGroupService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ConsumerGroupService.java
@@ -11,7 +11,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.UUID;
-import java.util.function.Function;
+import java.util.function.ToIntFunction;
 import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import lombok.RequiredArgsConstructor;
@@ -141,18 +141,25 @@ public class ConsumerGroupService {
       case NAME:
         return Comparator.comparing(ConsumerGroupDescription::groupId);
       case STATE:
-        Function<ConsumerGroupDescription, Integer> statesPriorities = cg -> {
+        ToIntFunction<ConsumerGroupDescription> statesPriorities = cg -> {
           switch (cg.state()) {
-            case STABLE: return 0;
-            case COMPLETING_REBALANCE: return 1;
-            case PREPARING_REBALANCE: return 2;
-            case EMPTY: return 3;
-            case DEAD: return 4;
-            case UNKNOWN: return 5;
-            default: return 100;
+            case STABLE:
+              return 0;
+            case COMPLETING_REBALANCE:
+              return 1;
+            case PREPARING_REBALANCE:
+              return 2;
+            case EMPTY:
+              return 3;
+            case DEAD:
+              return 4;
+            case UNKNOWN:
+              return 5;
+            default:
+              return 100;
           }
         };
-        return Comparator.comparingInt(statesPriorities::apply);
+        return Comparator.comparingInt(statesPriorities);
       case MEMBERS:
         return Comparator.comparingInt(cg -> -cg.members().size());
       default:
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/FeatureService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/FeatureService.java
index b7d4c0881a..24a824fb16 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/FeatureService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/FeatureService.java
@@ -44,7 +44,7 @@ public class FeatureService {
     if (controller != null) {
       features.add(
           isTopicDeletionEnabled(cluster, controller)
-              .flatMap(r -> r ? Mono.just(Feature.TOPIC_DELETION) : Mono.empty())
+              .flatMap(r -> Boolean.TRUE.equals(r) ? Mono.just(Feature.TOPIC_DELETION) : Mono.empty())
       );
     }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConfigSanitizer.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConfigSanitizer.java
index a09ae48161..30daa1ca57 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConfigSanitizer.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConfigSanitizer.java
@@ -30,7 +30,7 @@ class KafkaConfigSanitizer extends Sanitizer {
       var keysToSanitize = new HashSet<>(
           patternsToSanitize.isEmpty() ? DEFAULT_PATTERNS_TO_SANITIZE : patternsToSanitize);
       keysToSanitize.addAll(kafkaConfigKeysToSanitize());
-      setKeysToSanitize(keysToSanitize.toArray(new String[]{}));
+      setKeysToSanitize(keysToSanitize.toArray(new String[] {}));
     }
   }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConnectService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConnectService.java
index 1c3d247492..393a219d8e 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConnectService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KafkaConnectService.java
@@ -103,19 +103,19 @@ public class KafkaConnectService {
   }
 
   private Predicate<FullConnectorInfoDTO> matchesSearchTerm(final String search) {
-    return (connector) -> getSearchValues(connector)
+    return connector -> getSearchValues(connector)
         .anyMatch(value -> value.contains(
             StringUtils.defaultString(
-                search,
-                StringUtils.EMPTY)
+                    search,
+                    StringUtils.EMPTY)
                 .toUpperCase()));
   }
 
   private Stream<String> getSearchValues(FullConnectorInfoDTO fullConnectorInfo) {
     return Stream.of(
-        fullConnectorInfo.getName(),
-        fullConnectorInfo.getStatus().getState().getValue(),
-        fullConnectorInfo.getType().getValue())
+            fullConnectorInfo.getName(),
+            fullConnectorInfo.getStatus().getState().getValue(),
+            fullConnectorInfo.getType().getValue())
         .map(String::toUpperCase);
   }
 
@@ -158,7 +158,7 @@ public class KafkaConnectService {
             connector
                 .flatMap(c -> connectorExists(cluster, connectName, c.getName())
                     .map(exists -> {
-                      if (exists) {
+                      if (Boolean.TRUE.equals(exists)) {
                         throw new ValidationException(
                             String.format("Connector with name %s already exists", c.getName()));
                       }
@@ -179,7 +179,7 @@ public class KafkaConnectService {
   }
 
   public Mono<ConnectorDTO> getConnector(KafkaCluster cluster, String connectName,
-                                      String connectorName) {
+                                         String connectorName) {
     return withConnectClient(cluster, connectName)
         .flatMap(client -> client.getConnector(connectorName)
             .map(kafkaConnectMapper::fromClient)
@@ -240,8 +240,8 @@ public class KafkaConnectService {
   }
 
   public Mono<ConnectorDTO> setConnectorConfig(KafkaCluster cluster, String connectName,
-                                            String connectorName, Mono<Object> requestBody) {
-    return  withConnectClient(cluster, connectName)
+                                               String connectorName, Mono<Object> requestBody) {
+    return withConnectClient(cluster, connectName)
         .flatMap(c ->
             requestBody
                 .flatMap(body -> c.setConnectorConfig(connectorName, (Map<String, Object>) body))
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KsqlService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KsqlService.java
index 7fe54bf03b..4e970dc0c8 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KsqlService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/KsqlService.java
@@ -20,7 +20,7 @@ public class KsqlService {
   private final List<BaseStrategy> ksqlStatementStrategies;
 
   public Mono<KsqlCommandResponseDTO> executeKsqlCommand(KafkaCluster cluster,
-                                                      Mono<KsqlCommandDTO> ksqlCommand) {
+                                                         Mono<KsqlCommandDTO> ksqlCommand) {
     return Mono.justOrEmpty(cluster)
         .map(KafkaCluster::getKsqldbServer)
         .onErrorResume(e -> {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MessagesService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MessagesService.java
index 0a5dc14737..34eca2ac3f 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MessagesService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MessagesService.java
@@ -84,7 +84,7 @@ public class MessagesService {
                                           CreateTopicMessageDTO msg) {
     if (msg.getPartition() != null
         && msg.getPartition() > metricsCache.get(cluster).getTopicDescriptions()
-          .get(topic).partitions().size() - 1) {
+        .get(topic).partitions().size() - 1) {
       throw new ValidationException("Invalid partition");
     }
     RecordSerDe serde =
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MetricsService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MetricsService.java
index f6bf6b552d..565d6e74bc 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MetricsService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/MetricsService.java
@@ -60,7 +60,7 @@ public class MetricsService {
   }
 
   private Mono<InternalLogDirStats> getLogDirInfo(KafkaCluster cluster, ReactiveAdminClient c) {
-    if (cluster.getDisableLogDirsCollection() == null || !cluster.getDisableLogDirsCollection()) {
+    if (!cluster.isDisableLogDirsCollection()) {
       return c.describeLogDirs().map(InternalLogDirStats::new);
     }
     return Mono.just(InternalLogDirStats.empty());
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/SchemaRegistryService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/SchemaRegistryService.java
index eda4a4dc36..8e04b1ebac 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/SchemaRegistryService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/SchemaRegistryService.java
@@ -5,7 +5,7 @@ import static org.springframework.http.HttpStatus.UNPROCESSABLE_ENTITY;
 
 import com.provectus.kafka.ui.exception.SchemaFailedToDeleteException;
 import com.provectus.kafka.ui.exception.SchemaNotFoundException;
-import com.provectus.kafka.ui.exception.SchemaTypeIsNotSupportedException;
+import com.provectus.kafka.ui.exception.SchemaTypeNotSupportedException;
 import com.provectus.kafka.ui.exception.UnprocessableEntityException;
 import com.provectus.kafka.ui.exception.ValidationException;
 import com.provectus.kafka.ui.mapper.ClusterMapper;
@@ -212,7 +212,7 @@ public class SchemaRegistryService {
         .onStatus(UNPROCESSABLE_ENTITY::equals,
             r -> r.bodyToMono(ErrorResponse.class)
                 .flatMap(x -> Mono.error(isUnrecognizedFieldSchemaTypeMessage(x.getMessage())
-                    ? new SchemaTypeIsNotSupportedException()
+                    ? new SchemaTypeNotSupportedException()
                     : new UnprocessableEntityException(x.getMessage()))))
         .bodyToMono(SubjectIdResponse.class);
   }
@@ -294,7 +294,9 @@ public class SchemaRegistryService {
   }
 
   public String formatted(String str, Object... args) {
-    return new Formatter().format(str, args).toString();
+    try (Formatter formatter = new Formatter()) {
+      return formatter.format(str, args).toString();
+    }
   }
 
   private void setBasicAuthIfEnabled(InternalSchemaRegistry schemaRegistry, HttpHeaders headers) {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java
index f0929b1ac3..ae57a668a9 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/TopicsService.java
@@ -80,14 +80,14 @@ public class TopicsService {
                                            Optional<TopicColumnsToSortDTO> sortBy,
                                            Optional<SortOrderDTO> sortOrder) {
     return adminClientService.get(cluster).flatMap(ac ->
-      new Pagination(ac, metricsCache.get(cluster))
-          .getPage(pageNum, nullablePerPage, showInternal, search, sortBy, sortOrder)
-          .flatMap(page ->
-              loadTopics(cluster, page.getTopics())
-                  .map(topics ->
-                      new TopicsResponseDTO()
-                          .topics(topics.stream().map(clusterMapper::toTopic).collect(toList()))
-                          .pageCount(page.getTotalPages()))));
+        new Pagination(ac, metricsCache.get(cluster))
+            .getPage(pageNum, nullablePerPage, showInternal, search, sortBy, sortOrder)
+            .flatMap(page ->
+                loadTopics(cluster, page.getTopics())
+                    .map(topics ->
+                        new TopicsResponseDTO()
+                            .topics(topics.stream().map(clusterMapper::toTopic).collect(toList()))
+                            .pageCount(page.getTotalPages()))));
   }
 
   private Mono<List<InternalTopic>> loadTopics(KafkaCluster c, List<String> topics) {
@@ -193,31 +193,31 @@ public class TopicsService {
 
   public Mono<TopicDTO> recreateTopic(KafkaCluster cluster, String topicName) {
     return loadTopic(cluster, topicName)
-            .flatMap(t -> deleteTopic(cluster, topicName)
-                    .thenReturn(t).delayElement(Duration.ofSeconds(recreateDelayInSeconds))
-                    .flatMap(topic -> adminClientService.get(cluster).flatMap(ac -> ac.createTopic(topic.getName(),
-                                            topic.getPartitionCount(),
-                                            (short) topic.getReplicationFactor(),
-                                            topic.getTopicConfigs()
-                                                    .stream()
-                                                    .collect(Collectors
-                                                            .toMap(InternalTopicConfig::getName,
-                                                                    InternalTopicConfig::getValue)))
-                                    .thenReturn(topicName))
-                            .retryWhen(Retry.fixedDelay(recreateMaxRetries,
-                                            Duration.ofSeconds(recreateDelayInSeconds))
-                                    .filter(throwable -> throwable instanceof TopicExistsException)
-                                    .onRetryExhaustedThrow((a, b) ->
-                                            new TopicRecreationException(topicName,
-                                                    recreateMaxRetries * recreateDelayInSeconds)))
-                            .flatMap(a -> loadTopic(cluster, topicName)).map(clusterMapper::toTopic)
-                    )
-            );
+        .flatMap(t -> deleteTopic(cluster, topicName)
+            .thenReturn(t).delayElement(Duration.ofSeconds(recreateDelayInSeconds))
+            .flatMap(topic -> adminClientService.get(cluster).flatMap(ac -> ac.createTopic(topic.getName(),
+                        topic.getPartitionCount(),
+                        (short) topic.getReplicationFactor(),
+                        topic.getTopicConfigs()
+                            .stream()
+                            .collect(Collectors
+                                .toMap(InternalTopicConfig::getName,
+                                    InternalTopicConfig::getValue)))
+                    .thenReturn(topicName))
+                .retryWhen(Retry.fixedDelay(recreateMaxRetries,
+                        Duration.ofSeconds(recreateDelayInSeconds))
+                    .filter(TopicExistsException.class::isInstance)
+                    .onRetryExhaustedThrow((a, b) ->
+                        new TopicRecreationException(topicName,
+                            recreateMaxRetries * recreateDelayInSeconds)))
+                .flatMap(a -> loadTopic(cluster, topicName)).map(clusterMapper::toTopic)
+            )
+        );
   }
 
   private Mono<InternalTopic> updateTopic(KafkaCluster cluster,
-                                         String topicName,
-                                         TopicUpdateDTO topicUpdate) {
+                                          String topicName,
+                                          TopicUpdateDTO topicUpdate) {
     return adminClientService.get(cluster)
         .flatMap(ac ->
             ac.updateTopicConfig(topicName, topicUpdate.getConfigs())
@@ -403,10 +403,11 @@ public class TopicsService {
           );
           return ac.createPartitions(newPartitionsMap)
               .then(loadTopic(cluster, topicName));
-        })
-        .map(t -> new PartitionsIncreaseResponseDTO()
+        }).map(t -> new PartitionsIncreaseResponseDTO()
             .topicName(t.getName())
-            .totalPartitionsCount(t.getPartitionCount())));
+            .totalPartitionsCount(t.getPartitionCount())
+        )
+    );
   }
 
   public Mono<Void> deleteTopic(KafkaCluster cluster, String topicName) {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ZookeeperService.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ZookeeperService.java
index d7563fc458..03638afc7f 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ZookeeperService.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ZookeeperService.java
@@ -15,7 +15,6 @@ import org.apache.zookeeper.ZooKeeper;
 import org.springframework.stereotype.Service;
 import org.springframework.util.StringUtils;
 import reactor.core.publisher.Mono;
-import reactor.core.scheduler.Schedulers;
 
 @Service
 @RequiredArgsConstructor
@@ -82,10 +81,11 @@ public class ZookeeperService {
 
   private ZooKeeper createClient(KafkaCluster cluster) {
     try {
-      return new ZooKeeper(cluster.getZookeeper(), 60 * 1000, watchedEvent -> {});
+      return new ZooKeeper(cluster.getZookeeper(), 60 * 1000, watchedEvent -> {
+      });
     } catch (IOException e) {
       log.error("Error while creating a zookeeper client for cluster [{}]",
-              cluster.getName());
+          cluster.getName());
       throw new ZooKeeperException(e);
     }
   }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/KsqlApiClient.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/KsqlApiClient.java
index 0604b9a9ff..ebd5bd86a5 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/KsqlApiClient.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/KsqlApiClient.java
@@ -101,7 +101,7 @@ public class KsqlApiClient {
     if (parsed.getStatements().size() > 1) {
       throw new ValidationException("Only single statement supported now");
     }
-    if (parsed.getStatements().size() == 0) {
+    if (parsed.getStatements().isEmpty()) {
       throw new ValidationException("No valid ksql statement found");
     }
     if (KsqlGrammar.isSelect(parsed.getStatements().get(0))) {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/KsqlGrammar.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/KsqlGrammar.java
index efb759258c..a98ac20bb5 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/KsqlGrammar.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/KsqlGrammar.java
@@ -18,6 +18,9 @@ import org.antlr.v4.runtime.atn.PredictionMode;
 
 class KsqlGrammar {
 
+  private KsqlGrammar() {
+  }
+
   @Value
   static class KsqlStatements {
     List<KsqlGrammarParser.SingleStatementContext> statements;
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/response/DynamicParser.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/response/DynamicParser.java
index c86a3293ff..384a73af38 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/response/DynamicParser.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/response/DynamicParser.java
@@ -12,6 +12,9 @@ import java.util.stream.StreamSupport;
 
 class DynamicParser {
 
+  private DynamicParser() {
+  }
+
   static KsqlResponseTable parseArray(String tableName, JsonNode array) {
     return parseArray(tableName, getFieldNamesFromArray(array), array);
   }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/response/ResponseParser.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/response/ResponseParser.java
index 7e0d8cb483..eccc19f0f6 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/response/ResponseParser.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/service/ksql/response/ResponseParser.java
@@ -14,6 +14,9 @@ import org.springframework.web.reactive.function.client.WebClientResponseExcepti
 
 public class ResponseParser {
 
+  private ResponseParser() {
+  }
+
   public static Optional<KsqlApiClient.KsqlResponseTable> parseSelectResponse(JsonNode jsonNode) {
     // in response we getting either header record or row data
     if (arrayFieldNonEmpty(jsonNode, "header")) {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/ClusterUtil.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/ClusterUtil.java
index c39135c49e..48315dd0ce 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/ClusterUtil.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/ClusterUtil.java
@@ -18,6 +18,9 @@ import org.apache.kafka.common.utils.Bytes;
 @Slf4j
 public class ClusterUtil {
 
+  private ClusterUtil() {
+  }
+
   private static final ZoneId UTC_ZONE_ID = ZoneId.of("UTC");
 
   public static int convertToIntServerStatus(ServerStatusDTO serverStatus) {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/JmxClusterUtil.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/JmxClusterUtil.java
index 834e346d88..b0b2b36d81 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/JmxClusterUtil.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/JmxClusterUtil.java
@@ -86,14 +86,14 @@ public class JmxClusterUtil {
 
   @SneakyThrows
   private List<MetricDTO> getJmxMetrics(String host, int port, boolean jmxSsl,
-                                    @Nullable String username, @Nullable String password) {
+                                        @Nullable String username, @Nullable String password) {
     String jmxUrl = JMX_URL + host + ":" + port + "/" + JMX_SERVICE_TYPE;
     final var connectionInfo = JmxConnectionInfo.builder()
-            .url(jmxUrl)
-            .ssl(jmxSsl)
-            .username(username)
-            .password(password)
-            .build();
+        .url(jmxUrl)
+        .ssl(jmxSsl)
+        .username(username)
+        .password(password)
+        .build();
     JMXConnector srv;
     try {
       srv = pool.borrowObject(connectionInfo);
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/JmxPoolFactory.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/JmxPoolFactory.java
index c5e7f91fe8..49e73a58f2 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/JmxPoolFactory.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/JmxPoolFactory.java
@@ -21,7 +21,7 @@ public class JmxPoolFactory extends BaseKeyedPooledObjectFactory<JmxConnectionIn
   public JMXConnector create(JmxConnectionInfo info) throws Exception {
     Map<String, Object> env = new HashMap<>();
     if (StringUtils.isNotEmpty(info.getUsername()) && StringUtils.isNotEmpty(info.getPassword())) {
-      env.put("jmx.remote.credentials", new String[]{info.getUsername(), info.getPassword()});
+      env.put("jmx.remote.credentials", new String[] {info.getUsername(), info.getPassword()});
     }
 
     if (info.isSsl()) {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/KafkaConstants.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/KafkaConstants.java
index faeb40179d..7b044fe087 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/KafkaConstants.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/KafkaConstants.java
@@ -30,20 +30,21 @@ import java.util.Map;
 
 public final class KafkaConstants {
 
+  private static final String LONG_MAX_STRING = Long.valueOf(Long.MAX_VALUE).toString();
+
   public static final Map<String, String> TOPIC_DEFAULT_CONFIGS = Map.ofEntries(
       new AbstractMap.SimpleEntry<>(CLEANUP_POLICY_CONFIG, CLEANUP_POLICY_DELETE),
       new AbstractMap.SimpleEntry<>(COMPRESSION_TYPE_CONFIG, "producer"),
       new AbstractMap.SimpleEntry<>(DELETE_RETENTION_MS_CONFIG, "86400000"),
       new AbstractMap.SimpleEntry<>(FILE_DELETE_DELAY_MS_CONFIG, "60000"),
-      new AbstractMap.SimpleEntry<>(FLUSH_MESSAGES_INTERVAL_CONFIG, "9223372036854775807"),
-      new AbstractMap.SimpleEntry<>(FLUSH_MS_CONFIG, "9223372036854775807"),
+      new AbstractMap.SimpleEntry<>(FLUSH_MESSAGES_INTERVAL_CONFIG, LONG_MAX_STRING),
+      new AbstractMap.SimpleEntry<>(FLUSH_MS_CONFIG, LONG_MAX_STRING),
       new AbstractMap.SimpleEntry<>("follower.replication.throttled.replicas", ""),
       new AbstractMap.SimpleEntry<>(INDEX_INTERVAL_BYTES_CONFIG, "4096"),
       new AbstractMap.SimpleEntry<>("leader.replication.throttled.replicas", ""),
-      new AbstractMap.SimpleEntry<>(MAX_COMPACTION_LAG_MS_CONFIG, "9223372036854775807"),
+      new AbstractMap.SimpleEntry<>(MAX_COMPACTION_LAG_MS_CONFIG, LONG_MAX_STRING),
       new AbstractMap.SimpleEntry<>(MAX_MESSAGE_BYTES_CONFIG, "1000012"),
-      new AbstractMap.SimpleEntry<>(MESSAGE_TIMESTAMP_DIFFERENCE_MAX_MS_CONFIG,
-          "9223372036854775807"),
+      new AbstractMap.SimpleEntry<>(MESSAGE_TIMESTAMP_DIFFERENCE_MAX_MS_CONFIG, LONG_MAX_STRING),
       new AbstractMap.SimpleEntry<>(MESSAGE_TIMESTAMP_TYPE_CONFIG, "CreateTime"),
       new AbstractMap.SimpleEntry<>(MIN_CLEANABLE_DIRTY_RATIO_CONFIG, "0.5"),
       new AbstractMap.SimpleEntry<>(MIN_COMPACTION_LAG_MS_CONFIG, "0"),
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeek.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeek.java
index b282a9f4c0..fa3ff78e02 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeek.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeek.java
@@ -107,8 +107,8 @@ public abstract class OffsetsSeek {
           .collect(Collectors.toMap(Tuple2::getT1, Tuple2::getT2));
 
       this.beginOffsets = this.endOffsets.keySet().stream()
-         .map(p -> Tuples.of(p, allBeginningOffsets.get(new TopicPartition(topic, p))))
-         .collect(Collectors.toMap(Tuple2::getT1, Tuple2::getT2));
+          .map(p -> Tuples.of(p, allBeginningOffsets.get(new TopicPartition(topic, p))))
+          .collect(Collectors.toMap(Tuple2::getT1, Tuple2::getT2));
     }
 
     public List<TopicPartition> topicPartitions() {
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeekBackward.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeekBackward.java
index c05791c293..e3d8f1b5b8 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeekBackward.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeekBackward.java
@@ -36,13 +36,13 @@ public class OffsetsSeekBackward extends OffsetsSeek {
 
 
   protected Map<TopicPartition, Long> offsetsFromPositions(Consumer<Bytes, Bytes> consumer,
-                                        List<TopicPartition> partitions) {
+                                                           List<TopicPartition> partitions) {
 
     return findOffsetsInt(consumer, consumerPosition.getSeekTo(), partitions);
   }
 
   protected Map<TopicPartition, Long> offsetsFromBeginning(Consumer<Bytes, Bytes> consumer,
-                                            List<TopicPartition> partitions) {
+                                                           List<TopicPartition> partitions) {
     return findOffsets(consumer, Map.of(), partitions);
   }
 
@@ -51,7 +51,7 @@ public class OffsetsSeekBackward extends OffsetsSeek {
         consumerPosition.getSeekTo().entrySet().stream()
             .collect(Collectors.toMap(
                 Map.Entry::getKey,
-                e -> e.getValue()
+                Map.Entry::getValue
             ));
     Map<TopicPartition, Long> offsetsForTimestamps = consumer.offsetsForTimes(timestampsToSearch)
         .entrySet().stream()
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeekForward.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeekForward.java
index 733726eae8..6b6ea735fc 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeekForward.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/OffsetsSeekForward.java
@@ -19,7 +19,7 @@ public class OffsetsSeekForward extends OffsetsSeek {
   }
 
   protected Map<TopicPartition, Long> offsetsFromPositions(Consumer<Bytes, Bytes> consumer,
-                                        List<TopicPartition> partitions) {
+                                                           List<TopicPartition> partitions) {
     final Map<TopicPartition, Long> offsets =
         offsetsFromBeginning(consumer, partitions);
 
@@ -54,7 +54,7 @@ public class OffsetsSeekForward extends OffsetsSeek {
   }
 
   protected Map<TopicPartition, Long> offsetsFromBeginning(Consumer<Bytes, Bytes> consumer,
-                                            List<TopicPartition> partitions) {
+                                                           List<TopicPartition> partitions) {
     return consumer.beginningOffsets(partitions);
   }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/AvroJsonSchemaConverter.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/AvroJsonSchemaConverter.java
index e6cff30893..61f742e721 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/AvroJsonSchemaConverter.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/AvroJsonSchemaConverter.java
@@ -59,7 +59,8 @@ public class AvroJsonSchemaConverter implements JsonSchemaConverter<Schema> {
           }
         case ARRAY:
           return createArraySchema(name, schema, definitions);
-        default: throw new RuntimeException("Unknown type");
+        default:
+          throw new RuntimeException("Unknown type");
       }
     } else {
       return createUnionSchema(schema, definitions);
@@ -87,9 +88,9 @@ public class AvroJsonSchemaConverter implements JsonSchemaConverter<Schema> {
     if (nullable) {
       return new OneOfFieldSchema(
           List.of(
-             new SimpleFieldSchema(new SimpleJsonType(JsonType.Type.NULL)),
-             new ObjectFieldSchema(fields, Collections.emptyList())
-         )
+              new SimpleFieldSchema(new SimpleJsonType(JsonType.Type.NULL)),
+              new ObjectFieldSchema(fields, Collections.emptyList())
+          )
       );
     } else {
       return new ObjectFieldSchema(fields, Collections.emptyList());
@@ -138,14 +139,18 @@ public class AvroJsonSchemaConverter implements JsonSchemaConverter<Schema> {
       case BYTES:
       case STRING:
         return new SimpleJsonType(JsonType.Type.STRING);
-      case NULL: return new SimpleJsonType(JsonType.Type.NULL);
-      case ARRAY: return new SimpleJsonType(JsonType.Type.ARRAY);
+      case NULL:
+        return new SimpleJsonType(JsonType.Type.NULL);
+      case ARRAY:
+        return new SimpleJsonType(JsonType.Type.ARRAY);
       case FIXED:
       case FLOAT:
       case DOUBLE:
         return new SimpleJsonType(JsonType.Type.NUMBER);
-      case BOOLEAN: return new SimpleJsonType(JsonType.Type.BOOLEAN);
-      default: return new SimpleJsonType(JsonType.Type.STRING);
+      case BOOLEAN:
+        return new SimpleJsonType(JsonType.Type.BOOLEAN);
+      default:
+        return new SimpleJsonType(JsonType.Type.STRING);
     }
   }
 }
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/JsonType.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/JsonType.java
index 23aa4b7790..79d73c6813 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/JsonType.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/JsonType.java
@@ -8,7 +8,7 @@ public abstract class JsonType {
 
   protected final Type type;
 
-  public JsonType(Type type) {
+  protected JsonType(Type type) {
     this.type = type;
   }
 
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/ObjectFieldSchema.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/ObjectFieldSchema.java
index 296c5e0715..7a279e465e 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/ObjectFieldSchema.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/ObjectFieldSchema.java
@@ -2,10 +2,7 @@ package com.provectus.kafka.ui.util.jsonschema;
 
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.node.ArrayNode;
-import com.fasterxml.jackson.databind.node.BooleanNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
-import com.fasterxml.jackson.databind.node.TextNode;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
diff --git a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/ProtobufSchemaConverter.java b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/ProtobufSchemaConverter.java
index a442705047..57b4936323 100644
--- a/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/ProtobufSchemaConverter.java
+++ b/kafka-ui-api/src/main/java/com/provectus/kafka/ui/util/jsonschema/ProtobufSchemaConverter.java
@@ -41,9 +41,9 @@ public class ProtobufSchemaConverter implements JsonSchemaConverter<Descriptors.
         Tuples.of(
             o.getName(),
             new OneOfFieldSchema(
-              o.getFields().stream().map(
-                  Descriptors.FieldDescriptor::getName
-              ).map(fields::get).collect(Collectors.toList())
+                o.getFields().stream().map(
+                    Descriptors.FieldDescriptor::getName
+                ).map(fields::get).collect(Collectors.toList())
             )
         )
     ).collect(Collectors.toMap(
@@ -52,8 +52,8 @@ public class ProtobufSchemaConverter implements JsonSchemaConverter<Descriptors.
     ));
 
     final List<String> allOneOfFields = schema.getOneofs().stream().flatMap(o ->
-                o.getFields().stream().map(Descriptors.FieldDescriptor::getName)
-        ).collect(Collectors.toList());
+        o.getFields().stream().map(Descriptors.FieldDescriptor::getName)
+    ).collect(Collectors.toList());
 
     final Map<String, FieldSchema> excludedOneOf = fields.entrySet().stream()
         .filter(f -> !allOneOfFields.contains(f.getKey()))
@@ -79,7 +79,7 @@ public class ProtobufSchemaConverter implements JsonSchemaConverter<Descriptors.
   }
 
   private FieldSchema convertField(Descriptors.FieldDescriptor field,
-                              Map<String, FieldSchema> definitions) {
+                                   Map<String, FieldSchema> definitions) {
     final JsonType jsonType = convertType(field);
 
     FieldSchema fieldSchema;