How to migrate JSF Validator to Bean Validation? - jsf-2

Question

The usual way to perform JSF validation in an imperative manner is to add validator tag to JSF and have a corresponding Validator class like the following :
View:
<h:outputLabel for="email" value="*Enter Email: " title="Primary Email"/>
<h:inputText id="email" value="#{personView.per.email}" required="true" requiredMessage="email is required"
title="Primary Email" tabindex="3">
<f:validator validatorId="emailValidator" />
</h:inputText>
<h:message id="m2a" for="email" style="color:red"/> <p></p>
Validator:
public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {
log("Validating submitted email -- " + value.toString());
matcher = pattern.matcher(value.toString());
if (!matcher.matches()) {
FacesMessage msg =
new FacesMessage(" E-mail validation failed.",
"Please provide E-mail address in this format: abcd#abc.com");
msg.setSeverity(FacesMessage.SEVERITY_ERROR);
throw new ValidatorException(msg);
}
}
Now here the validation is getting triggered by the JSF. I want to change that part and want that the validation is instead triggered from another Controller via a Bean Validation constraint. That means that, I want to remove the following part :-
<f:validator validatorId="emailValidator" />
and want that this validation is triggered from another controller via a Bean Validation constraint.
Note that, I cannot add the constraint directly on the entity as the entity is a generated file. I want do the validation in the controller itself such that incase of error I could show the error message on the UI.
How can I go about it?
Explanation with some sample code would be appreciated.