corrected mistakes after review

src/main/java/mate/academy/rickandmorty/controller/CharactersController.java

@@ -15,7 +15,7 @@
 @RequestMapping("/characters")
 @RequiredArgsConstructor
 @Tag(name = "Characters management",
-        description = "Endpoints for managing characters from the Rick and Morty cartoon")
+        description = "Endpoints for retrieving characters from the Rick and Morty cartoon")
 public class CharactersController {
     private final CharacterService characterService;
 
@@ -26,7 +26,7 @@ public CharacterInternalDto getRandom() {
     }
 
     @GetMapping("/by-name")
-    @Operation(summary = "Get all characters by name part")
+    @Operation(summary = "Get all characters by name part ignore case")
     public List<CharacterInternalDto> getAllByNamePart(@RequestParam String namePart) {
         return characterService.getAllByNamePart(namePart);
     }

src/main/java/mate/academy/rickandmorty/service/RickAndMortyClient.java

@@ -16,14 +16,15 @@
 @Component
 @RequiredArgsConstructor
 public class RickAndMortyClient {
+    private static final int NUMBER_OF_PAGES = 42;
     private static final String basicUrl = "https://rickandmortyapi.com/api/character?page=%d";
     private final ObjectMapper objectMapper;
 
     public List<CharacterExternalDto> getCharacters() {
         List<CharacterExternalDto> charactersFromApi = new ArrayList<>();
         HttpClient httpClient = HttpClient.newHttpClient();
 
-        for (int i = 1; i <= 42; i++) {
+        for (int i = 1; i <= NUMBER_OF_PAGES; i++) {
             String url = String.format(basicUrl, i);
             HttpRequest httpRequest = HttpRequest.newBuilder()
                     .GET()

src/main/java/mate/academy/rickandmorty/service/character/CharacterServiceImpl.java

@@ -1,7 +1,7 @@
 package mate.academy.rickandmorty.service.character;
 
 import java.util.List;
-import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
 import lombok.RequiredArgsConstructor;
 import mate.academy.rickandmorty.dto.internal.CharacterInternalDto;
 import mate.academy.rickandmorty.mapper.CharacterMapper;
@@ -13,9 +13,10 @@
 @RequiredArgsConstructor
 public class CharacterServiceImpl implements CharacterService {
     private static final String EXC_MSG_CANT_FIND = "Can't find character with id ";
-    private final Random random;
     private final CharacterRepository characterRepository;
     private final CharacterMapper mapper;
+    private final ThreadLocalRandom random = ThreadLocalRandom.current();
+    private long numberOfCharacters;
 
     @Override
     public void saveAll(List<Character> characters) {
@@ -24,7 +25,11 @@ public void saveAll(List<Character> characters) {
 
     @Override
     public CharacterInternalDto getRandomCharacter() {
-        long randomId = random.nextLong(characterRepository.count());
+        if (numberOfCharacters == 0) {
+            numberOfCharacters = characterRepository.count();
+        }
+
+        long randomId = random.nextLong(numberOfCharacters);
         Character character =
                 characterRepository.findById(randomId)
                         .orElseThrow(() -> new RuntimeException(EXC_MSG_CANT_FIND + randomId));