Durchsetzen benutzerdefinierter Domänendaten-Einschränkungen mit ConstraintValidator

@Target({ElementType.FIELD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = IbanChecksumValidator.class)
@Documented
public @interface ValidIban {
    String message() default "Invalid IBAN checksum structure";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
}
 
@Component
public class IbanChecksumValidator implements ConstraintValidator<ValidIban, String> {
 
    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        if (value == null || value.isBlank()) {
            return true;
        }
        String sanitized = value.replaceAll("\\s+", "");
        return sanitized.matches("^[A-Z]{2}\\d{2}[A-Z0-9]{1,30}$");
    }
}
 
public record TransferRequest(@ValidIban String destinationIban, BigDecimal amount) {}