code: private Validator getDefaultValidator(final FacesContext context) throws FacesException {
          if (!beanValidationPresent) {
              return null;
          }
  
          ValidatorFactory validatorFactory;
          Object cachedObject = context.getExternalContext().getApplicationMap().get(BeanValidator.VALIDATOR_FACTORY_KEY);
          if (cachedObject instanceof ValidatorFactory) {
              validatorFactory = (ValidatorFactory) cachedObject;
          } else {
              try {
                  validatorFactory = Validation.buildDefaultValidatorFactory();
              } catch (ValidationException e) {
                  throw new FacesException("Could not build a default Bean Validator factory", e);
              }
              context.getExternalContext().getApplicationMap().put(BeanValidator.VALIDATOR_FACTORY_KEY, validatorFactory);
          }
          return validatorFactory.getValidator();
      }
docs: Get the default Bean Validation Validator to read the contraints for a property.