public List<User> list() {
   return userDAO.list();
 }
 public User update(User user) {
   return userDAO.update(user);
 }
 public User getUser(long userId) {
   return userDAO.getUser(userId);
 }
 public boolean delete(long userId) {
   return userDAO.remove(userId);
 }
 public User addUser(User user) {
   return userDAO.addUser(user);
 }