Creating a Basic JSF 2.2 Application - JSF and HTML5 - page 262

UserManager EJB implements UserManagerLocal interface as shown by Listing 10-19.
Listing 10-19. UserManager EJB
package com.jsfprohtml5.weather.model;
import java.util.List;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
@Stateless
public class UserManager implements UserManagerLocal {
@PersistenceContext(unitName = "weatherUnit")
EntityManager em;
@Override
public AppUser getUser(String userID, String password) {
Query query = em.createQuery("select appUser from AppUser appUser where "
+ "appUser.id = :id and appUser.password = :password");
query.setParameter("id", userID);
query.setParameter("password", password);
List<AppUser> result = query.getResultList();
if (result != null && result.size() > 0) {
return result.get(0);
}
return null;
}
@Override
public void registerUser(AppUser appUser) throws UserExistsException {
Query query = em.createQuery("select appUser from AppUser appUser where "
+ "appUser.id = :id");
query.setParameter("id", appUser.getId());
List<AppUser> result = query.getResultList();
if (result != null && result.size() > 0) {
throw new UserExistsException();
}
em.persist(appUser);
}
}