What I'd like to be able to do is to load set of classes, probably all in the same folder. All of which implement the same interface and are the same class, then in my code I'd like to be able to call functions on those classes.
Based on your answer to my question, it seems you want to define a game interface and then plug in any number of AI implementations, probably configured from a .properties file. This is fairly standard use of an API interface.
You define an EngineInterface providing a method that accepts game state and returns the move. Then you define multiple classes that all implement EngineInterface. Your driver reads a property file to get the names of the implementation classes, instantiates them with Class.forName() and stores them in a list and/or map. Then when the driver gets requests it invokes each implementation in turn and keeps track of the results.