Fixed null sorting for connect/schema/quatos

Author: germanosin

api/src/main/java/io/kafbat/ui/controller/ClientQuotasController.java

@@ -26,9 +26,21 @@
 public class ClientQuotasController extends AbstractController implements ClientQuotasApi, McpTool {
 
   private static final Comparator<ClientQuotaRecord> QUOTA_RECORDS_COMPARATOR =
-      Comparator.nullsLast(Comparator.comparing(ClientQuotaRecord::user))
-          .thenComparing(Comparator.nullsLast(Comparator.comparing(ClientQuotaRecord::clientId)))
-          .thenComparing(Comparator.nullsLast(Comparator.comparing(ClientQuotaRecord::ip)));
+          Comparator.nullsLast(
+            Comparator.comparing(ClientQuotaRecord::user, Comparator.nullsLast(String::compareTo))
+          )
+          .thenComparing(Comparator.nullsLast(
+              Comparator.comparing(
+                  ClientQuotaRecord::clientId,
+                  Comparator.nullsLast(String::compareTo)
+              )
+          ))
+          .thenComparing(Comparator.nullsLast(
+              Comparator.comparing(
+                  ClientQuotaRecord::ip,
+                  Comparator.nullsLast(String::compareTo)
+              )
+          ));
 
   private final ClientQuotaService clientQuotaService;
 

api/src/main/java/io/kafbat/ui/controller/KafkaConnectController.java

@@ -275,14 +275,26 @@ public Mono<ResponseEntity<ConnectorPluginConfigValidationResponseDTO>> validate
   }
 
   private Comparator<FullConnectorInfoDTO> getConnectorsComparator(ConnectorColumnsToSortDTO orderBy) {
-    var defaultComparator = Comparator.comparing(FullConnectorInfoDTO::getName);
+    var defaultComparator = Comparator.comparing(
+        FullConnectorInfoDTO::getName,
+        Comparator.nullsFirst(Comparator.naturalOrder())
+    );
     if (orderBy == null) {
       return defaultComparator;
     }
     return switch (orderBy) {
-      case CONNECT -> Comparator.comparing(FullConnectorInfoDTO::getConnect);
-      case TYPE -> Comparator.comparing(FullConnectorInfoDTO::getType);
-      case STATUS -> Comparator.comparing(fullConnectorInfoDTO -> fullConnectorInfoDTO.getStatus().getState());
+      case CONNECT -> Comparator.comparing(
+          FullConnectorInfoDTO::getConnect,
+          Comparator.nullsFirst(Comparator.naturalOrder())
+      );
+      case TYPE -> Comparator.comparing(
+          FullConnectorInfoDTO::getType,
+          Comparator.nullsFirst(Comparator.naturalOrder())
+      );
+      case STATUS -> Comparator.comparing(
+          fullConnectorInfoDTO -> fullConnectorInfoDTO.getStatus().getState(),
+          Comparator.nullsFirst(Comparator.naturalOrder())
+      );
       default -> defaultComparator;
     };
   }

api/src/main/java/io/kafbat/ui/controller/SchemasController.java

@@ -242,7 +242,7 @@ public Mono<ResponseEntity<SchemaSubjectsResponseDTO>> getSchemas(String cluster
 
           List<String> subjectsToRetrieve;
           boolean paginate = true;
-          var schemaComparator = Comparator.nullsFirst(getComparatorForSchema(orderBy));
+          var schemaComparator = getComparatorForSchema(orderBy);
           final Comparator<SubjectWithCompatibilityLevel> comparator =
               sortOrder == null || !sortOrder.equals(SortOrderDTO.DESC)
                   ? schemaComparator : schemaComparator.reversed();
@@ -286,16 +286,34 @@ private List<SubjectWithCompatibilityLevel> paginateSchemas(
 
   private Comparator<SubjectWithCompatibilityLevel> getComparatorForSchema(
       @Valid SchemaColumnsToSortDTO orderBy) {
-    var defaultComparator = Comparator.comparing(SubjectWithCompatibilityLevel::getSubject);
+    var defaultComparator = Comparator.comparing(
+        SubjectWithCompatibilityLevel::getSubject,
+        Comparator.nullsFirst(Comparator.naturalOrder())
+    );
     if (orderBy == null) {
       return defaultComparator;
     }
     return switch (orderBy) {
-      case SUBJECT -> Comparator.comparing(SubjectWithCompatibilityLevel::getSubject);
-      case ID -> Comparator.comparing(SubjectWithCompatibilityLevel::getId);
-      case TYPE -> Comparator.comparing(SubjectWithCompatibilityLevel::getSchemaType);
-      case COMPATIBILITY -> Comparator.comparing(SubjectWithCompatibilityLevel::getCompatibility);
-      case VERSION -> Comparator.nullsLast(Comparator.comparing(SubjectWithCompatibilityLevel::getVersion));
+      case SUBJECT -> Comparator.comparing(
+          SubjectWithCompatibilityLevel::getSubject,
+          Comparator.nullsFirst(Comparator.naturalOrder())
+      );
+      case ID -> Comparator.comparing(
+          SubjectWithCompatibilityLevel::getId,
+          Comparator.nullsFirst(Integer::compareTo)
+      );
+      case TYPE -> Comparator.comparing(
+          SubjectWithCompatibilityLevel::getSchemaType,
+          Comparator.nullsFirst(Comparator.naturalOrder())
+      );
+      case COMPATIBILITY -> Comparator.comparing(
+          SubjectWithCompatibilityLevel::getCompatibility,
+          Comparator.nullsFirst(Comparator.naturalOrder())
+      );
+      case VERSION -> Comparator.comparing(
+          SubjectWithCompatibilityLevel::getVersion,
+          Comparator.nullsFirst(Comparator.naturalOrder())
+      );
       default -> defaultComparator;
     };
   }