Java - Framework to "APIzize" any class and make it available on TCP?

I have an application where both the backend and the frontend are built in Java. The backend provides some functionalities like accessing the DB, etc. While the frontend built in Struts calls those functions.

I'm looking for a way to make any Java class easily callable on TCP, ideally开发者_运维知识库 in my mind this could be done by extending a specific class, let's say:

public class MyClass extends ThisIsAnAPI

making in this way all the public functions callable on a network protocol.

With such a framework the frontend could be easily implemented in other languages, like Ruby (On Rails), by making network requests to the backend APIs written in Java and exposed on TCP.

Any tips?

If you are likely to go to a JavaScript/Ajax UI then I would take the time to expose the backend as RESTful services. Using JAX/RS this is a matter of a few lines of a code and some annotations and an interface.

If you are staying pure Java, it's pretty trivial these days to turn a POJO into a remotely callable EJB: just a couple of annotations.

It may sound like overkill, but in terms of effort and cost (given a free app server such as WebSphere CE or JBoss) it's not that big a deal. However if you don't go for EJBs then you need to look at two big issues:

1. Security. You've got some TCP-callable services. How sensitive are those services? Do they need authentication and authorisation? You can all too easily open up sensitive databases to the whole company or even the internet.
2. Resilience and Scaling. How will you manage failure scenarios? EJBs exposed via RMI/IIOP can be clusterd and hence you can scale and deal with errors. If you start with a technology capable of doing that, even if you don't need the functionality right now, you are well placed for the future.

I would start with RMI which is designed to do this. You create an interface which the client uses and the server implements.

Try Hessian, which is a low-level TCP protocol also having bindings for several other platforms, so you will get C#/C++/Flash/... for free. I think it is a bit easier to work with compared to RMI.

If you need more portability for the future, consider exposing POJOs via SOAP/REST (most WS stacks have this ability, only few extra annotations are needed if any).

You might want to take a look at JMS. It's quite high level and easy to use, but you need to run a message broker. It's a bit of a different architecture to point-to-point communication.

As several persons have mentioned RMI you can look up spring which have support for this and I have myself used successfully. http://static.springsource.org/spring/docs/2.0.x/reference/remoting.html