How to Fix Validationerror in Spring Boot In Production

ValidationError in Spring Boot in Production

Spring Boot production validation errors come from Bean Validation (@Valid), custom validators, or configuration property validation at startup.

Production Causes

• @ConfigurationProperties validation failing with production values
• Request DTOs receiving data outside expected ranges
• Database constraint violations escalating to validation errors

Fix

Add structured error handling:

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<ErrorResponse> handleValidation(
            MethodArgumentNotValidException ex) {
        List<FieldError> errors = ex.getBindingResult()
            .getFieldErrors().stream()
            .map(e -> new FieldError(e.getField(),
                e.getDefaultMessage(),
                String.valueOf(e.getRejectedValue())))
            .toList();

        return ResponseEntity.badRequest()
            .body(new ErrorResponse("Validation failed", errors));
    }

    record FieldError(String field, String message, String rejected) {}
    record ErrorResponse(String message, List<FieldError> errors) {}
}

// Config validation
@Validated
@ConfigurationProperties(prefix = "app")
public record AppProperties(
    @NotBlank String apiKey,
    @Min(1) @Max(100) int poolSize
) {}

Use @Validated on configuration classes with @ConfigurationProperties to fail fast at startup.

Best Practices

Defensive coding prevents most instances of this error. Validate all inputs at system boundaries, set reasonable defaults, and log enough context to diagnose issues without exposing sensitive data. Code reviews should specifically check for unhandled edge cases around this error type.

Bugsly for Spring Boot

Bugsly captures both startup and request validation errors in Spring Boot, grouping them by DTO class and field to reveal which constraints are violated most often.