public static List<User> searchAllUsers(String searchby, String search) {
    Session session = getSessionFactory().getCurrentSession();
    session.beginTransaction();
    List<User> result = session.createQuery("from User where "+searchby+"='"+search+"'").list();
    session.getTransaction().commit();
    return result;
}

public static User searchLogin(String username, String password) {
    Session session = getSessionFactory().getCurrentSession();
    session.beginTransaction();
    List<User> result = session.createQuery("from User where username='"+username+"' and password='"+password+"'").list();
    session.getTransaction().commit();
    return (result.size() == 0) ? null : result.get(0);
}

Session session = getSessionFactory().getCurrentSession();
session.beginTransaction();
// operation
session.getTransaction().commit();