Simple rejectIfEmptyOrWhiteSpace validation

[Aleksandar Mitrev]

I'm trying to check if the form fields are empty inside spring flow declaration. I don't want to create Validator because I wan a simple check for form field required like
ValidationUtils.rejectIfEmptyOrWhiteSpace(errors, "name", "name.required" )
so is it possible to do this outside of validator class inside flow declaration - for example something like this:

<view-state id="patientInfo" model="model.Patient"> 
<expression evaluate="ValidationUtils.rejectIfEmptyOrWhiteSpace(errors, "name", "name.required")" />
............
</view-state>

If there is not such syntax in Spring, OGNL and EL, How can I preform this check inside validator for example

public class PatientValidator {
    public void validatePatientInfo(Patient patient, ValidationContext context){
           // preform check here for form field required 
    }
}