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.