refactor: GeneralResponse and i18n

src/main/java/mate/academy/bookstore/config/I18nConfig.java

@@ -1,5 +1,7 @@
 package mate.academy.bookstore.config;
 
+import java.nio.charset.StandardCharsets;
+import java.util.Locale;
 import org.springframework.context.MessageSource;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -8,13 +10,18 @@
 
 @Configuration
 public class I18nConfig {
+    private static final String DEFAULT_BUNDLE_PATH = "classpath:messages";
+    private static final Locale DEFAULT_LOCALE = Locale.ENGLISH;
+
     @Bean
     public MessageSource messageSource() {
         ReloadableResourceBundleMessageSource messageSource
                 = new ReloadableResourceBundleMessageSource();
 
-        messageSource.setBasename("classpath:messages");
-        messageSource.setDefaultEncoding("UTF-8");
+        messageSource.clearCache();
+        messageSource.setBasename(DEFAULT_BUNDLE_PATH);
+        messageSource.setDefaultLocale(DEFAULT_LOCALE);
+        messageSource.setDefaultEncoding(StandardCharsets.UTF_8.name());
         return messageSource;
     }
 

src/main/java/mate/academy/bookstore/controller/BookController.java

@@ -5,8 +5,11 @@
 import lombok.AllArgsConstructor;
 import mate.academy.bookstore.dto.BookDto;
 import mate.academy.bookstore.dto.BookRequestDto;
+import mate.academy.bookstore.response.ResponseHandler;
+import mate.academy.bookstore.response.SuccessResponse;
 import mate.academy.bookstore.service.BookService;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -17,32 +20,37 @@
 import org.springframework.web.bind.annotation.ResponseStatus;
 import org.springframework.web.bind.annotation.RestController;
 
+
 @RestController
 @RequestMapping("/api/books")
 @AllArgsConstructor
 public class BookController {
     private final BookService bookService;
 
     @GetMapping
-    public List<BookDto> getAll() {
-        return bookService.findAll();
+    public ResponseEntity<SuccessResponse<List<BookDto>>> getAll() {
+        return ResponseHandler.getSuccessResponse(
+                bookService.findAll());
     }
 
     @GetMapping("/{id}")
-    public BookDto getBookById(@PathVariable Long id) {
-        return bookService.getById(id);
+    public ResponseEntity<SuccessResponse<BookDto>> getBookById(@PathVariable Long id) {
+        return ResponseHandler.getSuccessResponse(
+                bookService.getById(id));
     }
 
     @PostMapping
-    @ResponseStatus(HttpStatus.CREATED)
-    public BookDto createBook(@Valid @RequestBody BookRequestDto bookDto) {
-        return bookService.save(bookDto);
+    public ResponseEntity<SuccessResponse<BookDto>> createBook(@Valid @RequestBody BookRequestDto bookDto) {
+        return ResponseHandler.getSuccessResponse(
+                bookService.save(bookDto),
+                HttpStatus.CREATED);
     }
 
     @PutMapping("/{id}")
-    public BookDto updateBookById(@PathVariable Long id,
+    public ResponseEntity<SuccessResponse<BookDto>> updateBookById(@PathVariable Long id,
                                   @RequestBody BookRequestDto bookRequestDto) {
-        return bookService.updateById(id, bookRequestDto);
+        return ResponseHandler.getSuccessResponse(
+                bookService.updateById(id, bookRequestDto));
     }
 
     @DeleteMapping("/{id}")

src/main/java/mate/academy/bookstore/exception/CustomGlobalExceptionHandler.java

@@ -0,0 +1,57 @@
+package mate.academy.bookstore.exception;
+
+import java.util.List;
+import mate.academy.bookstore.response.ErrorResponse;
+import mate.academy.bookstore.response.ResponseHandler;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.data.mapping.PropertyReferenceException;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.validation.ObjectError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class CustomGlobalExceptionHandler {
+    @ExceptionHandler(EntityNotFoundException.class)
+    public ResponseEntity<ErrorResponse> handleEntityNotFoundException(
+            EntityNotFoundException ex) {
+        return ResponseHandler.getErrorResponse(
+                ex.getMessage(), HttpStatus.NOT_FOUND);
+    }
+
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<ErrorResponse> handleValidationExceptions(
+            MethodArgumentNotValidException ex) {
+        List<ErrorResponse.Message> errors = ex.getBindingResult().getAllErrors()
+                .stream()
+                .map(this::getErrorMessage)
+                .toList();
+        return ResponseHandler.getErrorResponse(
+                errors, HttpStatus.BAD_REQUEST);
+    }
+
+    @ExceptionHandler(PropertyReferenceException.class)
+    public ResponseEntity<ErrorResponse> handlePropertyReferenceException(
+            PropertyReferenceException ex) {
+        return ResponseHandler.getErrorResponse(
+                ex.getMessage(), HttpStatus.BAD_REQUEST);
+    }
+
+    @ExceptionHandler(DataIntegrityViolationException.class)
+    public ResponseEntity<ErrorResponse> handleDataIntegrityViolationException(
+            DataIntegrityViolationException ex) {
+        return ResponseHandler.getErrorResponse(
+                ex.getMessage(), HttpStatus.CONFLICT);
+    }
+
+    private ErrorResponse.Message getErrorMessage(ObjectError e) {
+        String field = null;
+        if (e instanceof FieldError fieldError) {
+            field = fieldError.getField();
+        }
+        return new ErrorResponse.Message(field, e.getDefaultMessage());
+    }
+}

src/main/java/mate/academy/bookstore/response/ErrorResponse.java

@@ -0,0 +1,18 @@
+package mate.academy.bookstore.response;
+
+import java.util.List;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+public class ErrorResponse extends GeneralResponse {
+    private List<Message> errors;
+
+    public record Message(String field, String message) {
+    }
+
+    public ErrorResponse(List<Message> errors, HttpStatus status) {
+        super(status);
+        this.errors = errors;
+    }
+}

src/main/java/mate/academy/bookstore/response/GeneralResponse.java

@@ -0,0 +1,21 @@
+package mate.academy.bookstore.response;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import java.util.Date;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+public abstract class GeneralResponse {
+    private boolean success;
+    private int status;
+
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd-MM-yyyy hh:mm:ss")
+    private Date timestamp;
+
+    public GeneralResponse(HttpStatus status) {
+        this.timestamp = new Date();
+        this.status = status.value();
+        this.success = status.is2xxSuccessful();
+    }
+}

src/main/java/mate/academy/bookstore/response/ResponseHandler.java

@@ -0,0 +1,32 @@
+package mate.academy.bookstore.response;
+
+import java.util.List;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+
+public class ResponseHandler {
+    public static ResponseEntity<ErrorResponse> getErrorResponse(
+            String message, HttpStatus status) {
+        return new ResponseEntity<>(
+                new ErrorResponse(List.of(new ErrorResponse.Message(null, message)), status),
+                status);
+    }
+
+    public static ResponseEntity<ErrorResponse> getErrorResponse(
+            List<ErrorResponse.Message> messages, HttpStatus status) {
+        return new ResponseEntity<>(
+                new ErrorResponse(messages, status),
+                status);
+    }
+
+    public static <T> ResponseEntity<SuccessResponse<T>> getSuccessResponse(T data) {
+        return getSuccessResponse(data, HttpStatus.OK);
+    }
+
+    public static <T> ResponseEntity<SuccessResponse<T>> getSuccessResponse(
+            T data, HttpStatus status) {
+        return new ResponseEntity<>(
+                new SuccessResponse<>(data, status),
+                status);
+    }
+}

src/main/java/mate/academy/bookstore/response/SuccessResponse.java

@@ -0,0 +1,14 @@
+package mate.academy.bookstore.response;
+
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+public class SuccessResponse<T> extends GeneralResponse {
+    private T data;
+
+    public SuccessResponse(T data, HttpStatus status) {
+        super(status);
+        this.data = data;
+    }
+}

src/main/java/mate/academy/bookstore/service/LocaleService.java

@@ -0,0 +1,5 @@
+package mate.academy.bookstore.service;
+
+public interface LocaleService {
+    String getMessage(String code);
+}