hstring = em.merge(hstring);
em.getTransaction().commit();
} catch (Exception ex) {
String msg = ex.getLocalizedMessage();
if (msg == null || msg.length() == 0) {
HstringPK id = hstring.getHstringPK();
if (findHstring(id) == null) {
throw new NonexistentEntityException("The hstring with id " + id + " no longer exists.");
}
}
throw ex;