Referencing a Method That Performs Validation

If the input of one of the components on your page is validated by a backing bean method, refer to the method from the component’s tag using the validator attribute.

The following example shows how to reference a method that performs validation on email, an input component:

<h:inputText id="email" value="#{checkoutFormBean.email}"
    size="25" maxlength="125"
    validator="#{checkoutFormBean.validateEmail}"/>