ha so [https://community.jboss.org/people/haso] created the discussion "Cant inject Bean class into Restfull WebService (JAX-RS)" To view the discussion, visit: https://community.jboss.org/message/821240#821240 -------------------------------------------------------------- I'm trying to save data acquired by Rest web service to database using hibernate/persistence. In one of my web modules i implemented that service. Database ejb connector is placed in EJB module. They are parts of EAR application. Every time when i call pb.addDevice() im getting  java.lang.NullPointerException when puting proper url with params in browser(worked till i wanted to save it to Database). Can't find what is wrong with it. I'm using jboss 6.1.0 Final. PS. when i changed from     @EJB     PersistenceBean pb; to     PersistenceBean pb = new PersistenceBean(); i got null pointer on  EntityManager em = emf.createEntityManager(); code:     @Stateless     @Path("/RestService")     public class RestPush  {     @EJB     PersistenceBean pb;         @GET           @Path("/RegisterDevice")         public void registerDevice(             @QueryParam("deviceId") String deviceId){             Device d = new Device(true);             d.setId = deviceId;             pb.addDevice(d);         }     } and EJB class:     @Stateless(mappedName = "PersistenceBean")     public class PersistenceBean {     @PersistenceUnit(unitName = "PersistentUnitName")     EntityManagerFactory emf;     private void persist(Object o, EntityManager entityManager) {         try {             entityManager.persist(o);         } catch (Exception e) {             logger.severe("Error writing to DB: " + e);             logger.severe("" + e.fillInStackTrace());         }     }       public void addDevice(Device d) {         try {             EntityManager em = emf.createEntityManager();         if (persist(device, em)) {                 logger.info("Device with id : " + device.getId()                         + " has been added ");     } else {                 logger.info("Failed to add device with id: " + device.getId());     } catch (Exception e) {             logger.severe("PersistenceBean: Could not save device.");             e.printStackTrace();     }     } -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/821240#821240] Start a new discussion in EJB3 at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]