Ejb injected in servlet

Question

hi
I injected ejb in my servlet and I have this error in my servlet
in my if condition that I get this error:
ava.lang.ClassCastException:
swch.api.BaseEntity.Terminal cannot be cast to swch.api.BaseEntity.Terminal
public interface ITrmnlAuthenticationBL{
public Terminal find ( String serialNo, String password)
               throws GeneralException;
@Stateless
public class TrmnlAuthenticationBL implements ITrmnlAuthenticationBL{
@EJB IPersistenceManager pm;
public Terminal find ( String serialNo, String password)
               throws GeneralException {
try {
     Terminal terminal = pm.getEntityManager().createQuery("from Terminal where password = :pass and serialNo = :serial ", Terminal.class)
.setParameter("pass", password).setParameter("serial",serialNo)
.getSingleResult();
return terminal;
}catch (NoResultException e) {
          e.printStackTrace();
          return null;
catch (Exception e) {
          e.printStackTrace();
          return null;
public class EnterLet extends HttpServlet {
@EJB
private ITrmnlAuthenticationBL trmnlMg;
@Override
     protected void doPost(HttpServletRequest request, HttpServletResponse response)
               throws ServletException, IOException {
String password = request.getParameter("ps");
Terminal terminal = trmnlMg.find(serialNo, password);
****if (terminal == null || ! password.equalsIgnoreCase(terminal.getPassword()) )
I have error in this line in if condition when I used "terminal.getPassword" and can not cast Termianl from hibernate to
Terminal entity in my project...
please explain my mistake
Edited by: Marzieh on Nov 17, 2011 1:13 AM

Answer 1

swch.api.BaseEntity.Terminal cannot be cast to swch.api.BaseEntity.TerminalWeird huh? Java is telling you that it cannot cast an object to the exact same type.
That means that you have classloader conflicts. The same class is loaded by two different classloaders, which probably means that you have a jar with the entity deployed in two different and isolated modules (war, ear, whatever). Even if the two classes are the same, because they come from two different classloaders, to Java they are different classes and not assignable to each other.
Is all this deployed in the same EAR? If it is you shouldn't be having this problem and you must be doing something really funky in the way you deploy the stuff. If it isn't, you should deploy everything in the same ear to fix the classpath conflicts.