There is nice like() method in JPA criteria API. Try to use that, hope it will help.
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery criteriaQuery = cb.createQuery(Employees.class);
Root<Employees> rootOfQuery = criteriaQuery.from(Employees.class);
criteriaQuery.select(rootOfQuery).where(cb.like(rootOfQuery.get("firstName"), "H%"));