Spring JPA and form filter

I have a web page with a search form (with name and surname fields) and a table of persons. When user inserts a name n and a surname s I have to show the persons with name like n and surname like s. When user inserts only the name I have to filter only by name and the same when user inserts only the surname.

My searchPersons method in Controller looks like:

@RequestMapping(value = RouteConfig.SEARCH_PERSONS)    
public @ResponseBody Page<Person> searchPersons(@ModelAttribute Person p, Pageable pageable) {
    return pazienteRepository.findAll(where(nameIsLike(p.getName())).and(surnameIsLike(p.getSurname())), pageable);
}

I write a PersonSpecifications class:

public class PersonSpecifications {

    public static Specification<Person> nomeIsLike(String name) {
        return (Root<Person> root, CriteriaQuery<?> query, CriteriaBuilder cb) -> 
                cb.like(cb.lower(root.<String>get(Person_.nome)), getLikePattern(name));
    }

    public static Specification<Person> surnameIsLike(String surname) {
        return (Root<Person> root, CriteriaQuery<?> query, CriteriaBuilder cb) ->
             cb.like(cb.lower(root.<String>get(Person_.surname)), getLikePattern(surname));
    }

Now if I have name and surname my search is ok. The problem is when name or surname is not valued in the web form.

What's the best practice in this situation?