enviar datos en json desde un serlet

[osmaymoya]

aqui les va el código

PosDeviceManager posdeviceManager = (PosDeviceManager)entityManager;

Gson gson= new Gson();
PrintWriter out = response.getWriter();
List<PosSale> data = posdeviceManager.getPosSaleManager().getEntities() ;
out.print(gson.toJson(data);
out.close();