JNDI error Please help.

Question

I'm developing an J2EE based web application which uses JSP and EJB's.
When I'm trying to access one EJB from a JSP page I get the following errors:
javax.naming.NamingException: Error instantiating web-app JNDI-context: No location specified and no suitable instance foun
for the ejb-ref 'ejb/MasterFacade', an EJB with matching home and remote name was found, but it was an Entity, not a Session
java.lang.reflect.InvocationTargetException: javax.ejb.EJBException
at thinksol.hms.action.cptAction.execute(cptAction.java:105)
at java.lang.reflect.Method.invoke(Native Method)
at thinksol.hms.controller.Controller.processRequest(Controller.java:74)
at thinksol.hms.controller.Controller.doGet(Controller.java:95)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:195)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:309)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:336)
at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:696)
at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:281)
at com.evermind.server.http.ServletRequestDispatcher.forward(ServletRequestDispatcher.java:195)
at com.evermind.server.http.GetParametersRequestDispatcher.forward(GetParametersRequestDispatcher.java:188)
at com.evermind.server.http.EvermindPageContext.forward(EvermindPageContext.java:199)
at __jspPage0_cptmasterForm_jsp._jspService(__jspPage0_cptmasterForm_jsp.java:39)
at com.orionserver.http.OrionHttpJspPage.service(OrionHttpJspPage.java:56)
at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:696)
at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:281)
at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:735)
at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:243)
at com.evermind.util.ThreadPoolThread.run(ThreadPoolThread.java:64)
The corresponding entry in my "web.xml" file is
          <ejb-ref>
          <ejb-ref-name>ejb/MasterFacade</ejb-ref-name>
          <ejb-ref-type>Session</ejb-ref-type>
          <home>thinksol.hms.facade.MasterFacadeHome</home>
          <remote>thinksol.hms.facade.MasterFacade</remote>
          </ejb-ref>
and the entry in "ejb-jar.xml" file is:
          <session>
          <ejb-name>MasterFacadeEJB</ejb-name>
          <home>thinksol.hms.facade.MasterFacadeHome</home>
          <remote>thinksol.hms.facade.MasterFacade</remote>
          <ejb-class>thinksol.hms.facade.MasterFacadeEJB</ejb-class>
          <session-type>Stateless</session-type>
          <transaction-type>Container</transaction-type>
     </session>
Please advice where I'm going wrong.
Thanks.
-Vaskar
[email protected]
--------------------           

Answer 1

I'm using ServiceLocator to Look up EJB's . The following is the important part of the Service Locator
------------------------<serviceLocator>-----------------
public class ServiceLocator {
private static ServiceLocator serviceLocatorRef = null;
private static Hashtable ejbHomeCache = null;
private static Hashtable     ejbLocalHomeCache = null;
private static Hashtable dataSourceCache = null;
static {
serviceLocatorRef = new ServiceLocator();
/*Private Constructor for the ServiceLocator*/
private ServiceLocator(){
ejbHomeCache      = new Hashtable();
ejbHomeCache.clear();
ejbLocalHomeCache     = new Hashtable();
ejbLocalHomeCache.clear();
dataSourceCache      = new Hashtable();
dataSourceCache.clear();
public static ServiceLocator getInstance(){
return serviceLocatorRef;
Start of Service Constants
/*Enumerating the different services available from the Service Locator*/
public static final int MasterFacade      = 1;
/*The JNDI Names used to lookup a service*/
public static final String MasterFacade_JNDINAME     ="java:comp/env/ejb/MasterFacade";
/*References to each of the different EJB Home Interfaces*/
public static final Class MasterFacadeCLASSREF           = MasterFacadeHome.class;
public String getServiceName(int pServiceId)
throws ServiceLocatorException{
String serviceName = null;
System.out.println("----------------------------------------------------------------------");
System.out.println("Inside ServiceConstants");
System.out.println("The value of pserviceId is : " +pServiceId);
switch (pServiceId){
     case Counter:           serviceName = Counter_JNDINAME;
                    break;
     case MasterFacade:           serviceName = MasterFacade_JNDINAME;
                                   break;
default: throw new ServiceLocatorException(
               "Unable to locate the service requested in " +
               "ServiceLocator.getServiceName() method. ");
     System.out.println("The value of serviceName is : " +serviceName);
     System.out.println("----------------------------------------------------------------------");
return serviceName;
public Class getEJBHomeRef(int pServiceId)
throws ServiceLocatorException{
Class homeRef = null;
switch (pServiceId){
case Counter:                homeRef = CounterCLASSREF;
                    break;
case MasterFacade:                     homeRef = MasterFacadeCLASSREF;
                         break;
default: throw new ServiceLocatorException(
               "Unable to locate the service requested in " +
               "ServiceLocator.getEJBHomeRef() method. ");
return homeRef;
End of Service Constants
public EJBHome getEJBHome(int pServiceId)
throws ServiceLocatorException{
/*Trying to find the JNDI Name for the requested service*/
String serviceName = getServiceName(pServiceId);
EJBHome ejbHome = null;
try{
/*Checking to see if I can find the EJBHome interface in cache*/
if (ejbHomeCache.containsKey(serviceName)){
               System.out.println("----------------------------------------------------------------------");
               System.out.println("Inside ServiceLocator getEJBHome <if>");
               System.out.println("The value of pserviceId is : " +pServiceId);
               System.out.println("The value of serviceName is : " +serviceName);
     System.out.println("----------------------------------------------------------------------");
               ejbHome = (EJBHome) ejbHomeCache.get(serviceName);
          return ejbHome;
else{
System.out.println("----------------------------------------------------------------------");
          System.out.println("Inside ServiceLocator getEJBHome <else>");
          System.out.println("The value of pserviceId is : " +pServiceId);
     System.out.println("The value of serviceName is : " +serviceName);
     System.out.println("----------------------------------------------------------------------");
     * If I could not find the EJBHome interface in the cache, look it
     * up and then cache it.
          System.out.println("Inside Service Locator <else> 1");
          Context ctx = new InitialContext();
          System.out.println("Inside Service Locator <else> 2");
Object jndiRef = ctx.lookup(serviceName);
System.out.println("Inside Service Locator <else> 3");
Object portableObj =
PortableRemoteObject.narrow(jndiRef, getEJBHomeRef(pServiceId));
System.out.println("Inside Service Locator <else> 4 + EJBHomeRef: "+ getEJBHomeRef(pServiceId));
ejbHome = (EJBHome) portableObj;
ejbHomeCache.put(serviceName, ejbHome);
          return ejbHome;
catch(NamingException e){
throw new ServiceLocatorException("Naming exception error in ServiceLocator.getEJBHome()" + e);
catch(Exception e){
throw new ServiceLocatorException("General exception in ServiceLocator.getEJBHome" + e);
------------------------</serviceLocator>-----------------
Then I'm looking up the EJB using the following code:
-------------------------<lookupEJB>--------------------
ServiceLocator locator = ServiceLocator.getInstance();
MasterFacadeHome home = (MasterFacadeHome) locator.getEJBHome(ServiceLocator.MasterFacade);
MasterFacade master = (MasterFacade)home.create();
-------------------------</lookupEJB>--------------------
Put simply I'm relying on the getEJBHome() method of service Locator to look up EJB.
Also I'm facing another strange problem, it goes like this:
I'have 6 Entity Beans(all CMP) and when I call them
from a Session Bean one by one i.e., serially the second Entity Bean Creation fails. But both the Entity Beans are working independently i.e., if I call only One Entity Bean and then deploy the app the Entity Bean creation succeeds. Similarly again I comment the first Entity Bean creation and call another Entity Bean then it gives no problems. But as soon as I try to call both Entity Beans from the Session Bean I start getting problems.
Thanks and Regards,
-Vaskar
[email protected]
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