Issue with EJB - Stateful Session Bean and Servlet - servlets

Question

I have a servlet code which calls a ejb stateful session bean code as follows,
public class UsesBeansSF extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
// do something
}
finally {}
}
private SessionBeanSFRemote lookupSessionBeanSFRemote() {
try {
Context c = new InitialContext();
return (SessionBeanSFRemote) c.lookup("java:global/MyEJBSF/SessionBeanSF!ejbSF.SessionBeanSFRemote");
} catch (NamingException ne) {
Logger.getLogger(getClass().getName()).log(Level.SEVERE, "exception caught", ne);
throw new RuntimeException(ne);
}
}
}
This code works well without the line between * marks. However, when I am adding SessionBeanSFRemote sessionBeanSF = lookupSessionBeanSFRemote() this line (means calling a Stateful Session Bean), the code is giving error. Actually, I have to call the stateless session bean in order to perform some job. Can anybody help me why it is happening ? Thanks in advance.
Error message is following:
type Exception report message
descriptionThe server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: PWC1392: Error instantiating servlet class websSF.comsSF.UsesBeansSF
root cause
com.sun.enterprise.container.common.spi.util.InjectionException:
Error creating managed object for class websSF.comsSF.UsesBeansSF
root cause
java.lang.reflect.InvocationTargetException
root cause
java.lang.RuntimeException: javax.naming.NamingException:
Lookup failed for 'java:global/MyEJBSF/SessionBeanSF!ejbSF.SessionBeanSFRemote' in SerialContext
[Root exception is javax.naming.NamingException:
ejb ref resolution error for remote business interfaceejbSF.SessionBeanSFRemote [Root exception is java.lang.NullPointerException]]
root cause
javax.naming.NamingException:
Lookup failed for 'java:global/MyEJBSF/SessionBeanSF!ejbSF.SessionBeanSFRemote' in SerialContext
[Root exception is javax.naming.NamingException:
ejb ref resolution error for remote business interfaceejbSF.SessionBeanSFRemote
[Root exception is java.lang.NullPointerException]]
root cause
javax.naming.NamingException: ejb ref resolution error for remote business
interfaceejbSF.SessionBeanSFRemote [Root exception is java.lang.NullPointerException]
root cause
java.lang.NullPointerException
note The full stack traces of the exception and its root causes are available in the GlassFish Server Open Source Edition 3.0.1 logs.
Server: GlassFish Server Open Source Edition 3.0.1

Answer 1

I'm not sure if you have properly set up your Stateful bean. You can try this:
#Stateful(mappedName = "ejb/myStatefulBean")
public class MyStatefulBean implements MyStatefulRemoteInterface {
// Your implementation
}
then you can look it up with:
InitialContext context = new InitialContext();
MyStatefulRemoteInterface myStatefulBean = (MyStatefulRemoteInterface) context.lookup("ejb/myStatefulBean");
Besides, this stateful bean should be saved into each client's session for re-using:
HttpSession clientSession = request.getSession(false);
clientSession.setAttribute("myStatefulBean", myStatefulBean);
In future requests, you can try to get the bean from the client' session first before creating a new one for him.