@Override public void deleteUnassginedFlights(List<FlightEntity> flightsUnassigned) { for (FlightEntity f : flightsUnassigned) { FlightEntity fD = em.find(FlightEntity.class, f.getId()); if (fD != null) { FlightEntity fRD = em.find(FlightEntity.class, fD.getReverseFlight().getId()); fD.setReverseFlight(null); fRD.setReverseFlight(null); em.remove(fD); em.remove(fRD); } } }