Using service Locator pattern to dynamically access remote EJBs

Question

Hi All,
Please help to guide me how I can use a service locator to retrieve a remote object (residing on another application but on same domain) .
I do not want to use Dependency Injection since I want to dynamically discover them ( there are many implementations of same interface (POJO)). Each EJB implementation implements its own remote/local interface that extends this global POJO interface.
I have two J2ee-Applications on same domain. J2EE-Application 1 has an EJB module (EJB Module 1) that intends to access an EJB Module (EJB Module 2) in J2EE-Application 2. Following observations:
1. Dependency Injection fails if (include the EJB Module 2 jar in J2EE-Application 1). Reason App Server complains the EJB has been deployed (Deployment fails)
2. Dependency Injection works if (exclude the EJB Module 2 jar in J2EE-Application 1) and include the Remote Interface in EJB Module 1(J2EE-Application 1).Positive Observation (Deployment success and DI also success)
3.Using Service Locator to retrieve the remote object if (exclude the EJB Module 2 jar in J2EE-Application 1) and include the Remote Interface in EJB Module 1(J2EE-Application 1). Negative and Positive Observation.
Positive Observation: Using dependency injection I can still retrieve the Remote Object
Another Positive: The Service Locator remote lookup to another Bean in same Application but different EJB Module is successful.
Negative Observation:
The Service Locator lookup to this same remote object with Successful Dependency Injection fails (An Ejb in a different application).
Can't retrieve the Remote Object with Service Locator. Message from Server:.
NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial.
Thanks in advance

Answer 1

"I do not want to use Dependency Injection since I want to dynamically discover them ( there are many implementations of same interface (POJO))"
If you're calling ejbs from other ejbs or servlets, the same could probably be acomplished by using dependency injection (@EJB) in a number of instance variables typed with different remote/local interfaces or even with different beanName attributes (for when more than one bean implements the same managed interface in the same app - not sure how it works outside the same jee app...) , and dinamically selecting one of them; or encapsulating those injected variables into a stateless ejb as your service locator to make them accessible from POJOs too (which, due to concurrent acess, wouldn't work for statefull ejbs references...).
Anyway, using the jndi lookup service locator pattern seems ok in this case.
What doesn't seem ok, given the nature of the error for the negative observation - jndi context initialization - is that
Another Positive: The Service Locator remote lookup to another Bean in same Application but different EJB Module is successful.
Can you check your code and reconfirm that you're using the same context initialization code for both the positive and negative observations ?