fix: update validation error serialization

Author: Cysteine12

server/src/main/java/org/eni/koinoniadaily/config/JwtFilter.java

@@ -77,7 +77,7 @@ protected void doFilterInternal(HttpServletRequest request, HttpServletResponse
                                       .error(HttpStatus.UNAUTHORIZED.getReasonPhrase())
                                       .message(ex.getMessage())
                                       .path(request.getRequestURI())
-                                      .errorCode(ex.getCause().getClass().getSimpleName())
+                                      .errorCode(ex.getCause() != null ? ex.getCause().getClass().getSimpleName() : "UNAUTHORIZED")
                                       .timestamp(Instant.now())
                                       .build();
 

server/src/main/java/org/eni/koinoniadaily/exceptions/GlobalExceptionHandler.java

@@ -1,6 +1,5 @@
 package org.eni.koinoniadaily.exceptions;
 
-import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.RequiredArgsConstructor;
 import org.eni.koinoniadaily.utils.ErrorResponse;
@@ -30,13 +29,18 @@ public class GlobalExceptionHandler {
   private static final Logger logger = LoggerFactory.getLogger(GlobalExceptionHandler.class);
 
   private ResponseEntity<ErrorResponse> buildResponse(WebRequest request, String message, HttpStatus status, String errorCode) {
+    return buildResponse(request, message, status, errorCode, null);
+  }
+
+  private ResponseEntity<ErrorResponse> buildResponse(WebRequest request, String message, HttpStatus status, String errorCode, Object errors) {
     ErrorResponse error = ErrorResponse.builder()
                             .success(false)
                             .status(status.value())
                             .error(status.getReasonPhrase())
                             .message(message)
                             .path(((ServletWebRequest) request).getRequest().getRequestURI())
                             .errorCode(errorCode)
+                            .errors(errors)
                             .timestamp(Instant.now())
                             .build();
 
@@ -59,19 +63,11 @@ public ResponseEntity<ErrorResponse> handleValidationException(MethodArgumentNot
                                       .stream()
                                       .collect(Collectors.toMap(
                                           FieldError::getField,
-                                          FieldError::getDefaultMessage,
-                                          (existing, replacement) -> existing
+                                          error -> error.getDefaultMessage() != null ? error.getDefaultMessage() : "Invalid value",
+                                          (existing, replacement) -> existing + ";" + replacement
                                       ));
 
-    String message;
-    try {
-      message = objectMapper.writeValueAsString(errors);
-    } catch (JsonProcessingException e) {
-      logger.error("Error serializing validation errors", e);
-      return buildResponse(request, "Validation failed with multiple errors", HttpStatus.UNPROCESSABLE_ENTITY, "VALIDATION_ERROR");
-    }
-
-    return buildResponse(request, message, HttpStatus.UNPROCESSABLE_ENTITY, "VALIDATION_ERROR");
+    return buildResponse(request, "Validation failed", HttpStatus.UNPROCESSABLE_ENTITY, "VALIDATION_ERROR", errors);
   }
 
   // Handle runtime validation errors

server/src/main/java/org/eni/koinoniadaily/exceptions/ValidationException.java

@@ -5,10 +5,11 @@
 @Getter
 public class ValidationException extends RuntimeException {
 
-  private String code = "VALIDATION_ERROR";
+  private final String code;
 
   public ValidationException(String message) {
     super(message);
+    this.code = "VALIDATION_ERROR";
   }
 
   public ValidationException(String code, String message) {

server/src/main/java/org/eni/koinoniadaily/utils/ErrorResponse.java

@@ -5,7 +5,7 @@
 import lombok.Getter;
 import lombok.experimental.SuperBuilder;
 
-//@Getter
+@Getter
 @SuperBuilder
 public class ErrorResponse extends ApiResponse {
 
@@ -17,5 +17,7 @@ public class ErrorResponse extends ApiResponse {
 
   private final String errorCode;
 
+  private final Object errors;
+
   private final Instant timestamp;
 }