EJBs in libraries - Reusing EJBs

Question

Let's say I want to create a library which I will use in future projects but I also want to include EJBs in that library referencing other EJBs etc.. That library would also contain simple java classes. What is the best way to do that? How do I define the dependencies in this case? I thought I would define them with annotations. If the user of the library wants to configure other dependencies he will be able to do so by overriding them inside the ejb-jar.xml of his project. Has anyone done something like this in the past? How would you go about it when developing in Eclipse?

Basically my problem is that as far as I can tell if I simply create an ejb-jar which I am going to include in all my projects the ejb container is going to instantiate my e.g. MDBs at deployment time even if I don't need all of the MDBs that are contained inside my library but only some of them.

Is a solution to not define MDBs as EJBs with annotations or inside the ejb-jar.xml but only their dependencies?

What about the session beans? Will they be automatically instantiated even if I don't use them inside a project?

Answer 1

EAR files. Although not very common, you could include your library and its dependencies in an EAR file and distribute that. What I'd like to do is to distribute the library in its own Jar file along with a documentation of dependencies (e.g.: a Maven' POM file or ivy's xml file). Either way, you'll need a dependency manager.

There is also an option to build a fat JAR file in which all the dependencies are exploded. I don't really like that. If I have to include dependencies, I'd go with EAR files.