Q:

How to inherit java classes in a Ruby on Rails environment

Background: I have a Java application that many programming clients interface with. Recently, a few clients wanted me to develop an API to allow them to inherit my application's Java classes in their Ruby documents without having to change their developing environment to Jruby - they want it to remain Ruby on Rails. 
In this post, it was mentioned that this could be accomplished by using XML or JSON as a middle-man between Java and Ruby on Rails.
Question: Is the XML/JSON method the best practice? If so, which do you find to be preferable (XML or JSON)? If not, what is a better practice?
Once a best practice is determined, some in-depth (as in-depth as you're willing to go) explanation as to how I should approach this would really be helpful. 
Thank you so much

A:

XML or JSON is really a matter of taste when talking server-level APIs. Both are text formats that can be trasmitted via HTTP, and either one can be consumed by a Rails application. 

