Accessing EJB3 without a home interface

[nbhatia]

According to the EJB 3.0 Spec:

The requirement for Home interfaces has been eliminated. Session beans are no longer required to have home interfaces. A client may acquire a reference to a session bean through one of the mechanisms described in Chapter 8.

I am trying to do exactly that, i.e. to access an EJB 3 from a remote client without a home interface. However I am getting a NameNotFoundException. Can someone help me understand how to do this?

Here's my session bean interface:

public interface HelloWorld {
 public String getHelloMessage();
}

Here's the implementation:

@Stateless @Remote
public class HelloWorldBean implements HelloWorld {

 public String getHelloMessage() {
 return "Hello World";
 }
}

Here's the call from the client:

public class HelloWorldEjb3Client {

 public static void main(String[] args) {

 try {
 // Look up the HelloWorld home interface
 Object obj = getContext().lookup("HelloWorld");
 HelloWorld helloWorld =
 (HelloWorld)javax.rmi.PortableRemoteObject.narrow(obj, HelloWorld.class );

 // Start using the HelloWorld object
 System.out.println(helloWorld.getHelloMessage());
 }
 catch (Exception e) {
 e.printStackTrace();
 }
 }

 public static final Context getContext() throws javax.naming.NamingException {
 System.out.println("Connecting to JBoss");
 Hashtable<String, String> env = new Hashtable<String, String>();
 env.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
 env.put(Context.PROVIDER_URL, "jnp://localhost:1099");
 env.put("java.naming.factory.url.pkgs", "org.jboss.naming:org.jnp.interfaces");
 return new InitialContext(env);
 }
}

The exception is:

javax.naming.NameNotFoundException: HelloWorld not bound

Here's my ejb-jar.xml. It is essentially empty. I created it just because the Maven EJB Plugin was complaining that it could not find a ejb-jar.xml. Since I am using annotations, I don't believe that I should require this file.

<?xml version="1.0" encoding="UTF-8"?>

<ejb-jar
 xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/ejb-jar_3_0.xsd"
 version="3.0">
</ejb-jar>

Looking at the JNDI tree, I believe that the HelloWorld bean has been deployed:

Global JNDI Namespace
 +- helloworldejb3-app-1.0 (class: org.jnp.interfaces.NamingContext)
 | +- HelloWorldBean (class: org.jnp.interfaces.NamingContext)
 | | +- remote (proxy: $Proxy64 implements interface samples.helloworldejb3.HelloWorld,interface org.jboss.ejb3.JBossProxy)

So what is the right way to access this bean from a remote client?

Thanks.
Naresh

[alrubinger]

Looks like you're almost there. Just make sure you're looking up the correct address in JNDI:

helloworldejb3-app-1.0/HelloWorldBean/remote

This is a common newbie problem; use the JNDIView (as you've done) to find the default JNDI Bind names for your EJBs.

S,
ALR

[nbhatia]

Thanks Andrew. That was the issue! So I have couple of follow up questions:

1) Is this JNDI name (helloworldejb3-app-1.0/HelloWorldBean/remote) implementation specific? Is there any way to give it a more user friendly JNDI name, such as "HelloWorld"?

2) Is there a nicer way to get a reference to the EJB in the client? As you can see, I am explicitly creating a context and using it to look us the bean. Can @EJB or @Resource annotations be used on the remote client to lookup the EJB or the Context?

Thanks.
Naresh

[alrubinger]

"nbhatia" wrote:
1) Is this JNDI name (helloworldejb3-app-1.0/HelloWorldBean/remote) implementation specific? Is there any way to give it a more user friendly JNDI name, such as "HelloWorld"?

@RemoteBinding / @LocalBinding / @RemoteHomeBinding / @LocalHomeBinding are JBos-specific annotations to accomplish just that. Also see jboss.xml equivalents.

"nbhatia" wrote:
2) Is there a nicer way to get a reference to the EJB in the client? As you can see, I am explicitly creating a context and using it to look us the bean. Can @EJB or @Resource annotations be used on the remote client to lookup the EJB or the Context?

Take a look at Java EE 5 Application Clients.

S,
ALR

[nbhatia]

Thanks Andrew. I was able to use @RemoteBinding to control the JNDI name. Now I would like to move this specification only to jboss.xml. However, I could not find much documentation around it. I have already looked through the following URLs

• 
  
• http://docs.jboss.org/ejb3/app-server/reference/build/reference/en/html/jboss_extensions.html
  
• http://docs.jboss.org/ejb3/app-server/reference/build/reference/en/html/jboss_deployment_descriptor.html
  
• http://docs.jboss.org/ejb3/app-server/reference/build/reference/en/html/partial_deployment_descriptors.html
  
  Any help would be greatly appreciated.
  
  Thanks.
  Naresh

[nbhatia]

Answering my own question :-). This is how I was able to do it:

<jboss version="3.0">

 <enterprise-beans>
 <session>
 <ejb-name>HelloWorldBean</ejb-name>
 <jndi-name>HelloWorld</jndi-name>
 </session>
 </enterprise-beans>

</jboss>