Emply EJB and Servlet

After reading about it for so long, I now have chance to get my hand dirty with EJB. I use Glassfish+Eclipse 3.7 on Ubuntu.

I first created an EJB that just returns a greeting message. Then I create the appl开发者_Python百科ication client to access this EJB using InitialContext. This works exactly like expected.

Then, I created a servlet to access to that EJB. Neither access with @EJB nor InitialContext works.

When I use @EJB, the 404 page appear with this description: "The requested resource () is not available."

When I use InitialContent, an ClassNotFoundException is thrown. Apparently, the class loader of the servlet cannot access to the EJB class. I tried to add EJB jar file to the servlet's lib folder and I got the error message that the JNDI name already exists. Apparently, Glass Fish tries publish the EJB in the Servlet's lib folder too.

The only way to get this to work is to publish the EJB with the servlet. This way, both I can get the servlet and a stand-alone application to access to that EJB. The problem is that I need to always employ the servlet with the EJB which is not desirable since my client may not want to use web front end.

Anyway, my question is what is appropriate way to have the servlet access to the EJB employed outside its class loader without repeatedly publishing the EJB.

P.S. It is also possible that the problem might be the way Eclipse configure and employ those components.

Thank a lot for any helps.

Perhaps you need to treat the EJB component as if it were remote. And maybe it really is since you don't give a lot of detail on how you are deploying. Try the directions at http://glassfish.java.net/javaee5/ejb/EJB_FAQ.html#nonJavaEEwebcontainerRemoteEJB.

A few pointers:

• you may need to put the webapp and the ejb-jar in an .ear (enterprise application) and deploy it to glassfish
• you may need the remote interfaces on the classpath of the webapp (if they are not available at runtime, but they were at compile time, you can't expect it to work)
• NetBeans is generally better with enterprise stuff and wizards for creating and deploying applications. Give it a try.

After try out a while, I found that I can do by referring it as "/". This even works with injection.