Groovy script runner architecture

Question

Initial info: I have a groovy app (let's call it Runner ) which is capable of running anything implementing certain interface (let's call it Runnable ). And I have a pool of Runnables (groovy scripts) which should be visible to this app at the init stage and which app will call (through the interface and passing an object as a param).

Task: What I need is a way to load and call all the Runnables from the Runner .

Requirements: It's tricky, as scripts may not follow certain package structure and can be placed on the same machine as Runner but virtually in any place. They can also be named differently (open discussion for mandatory java alike naming: class name == file name) and can be skipped for now (though if there's gonna be advice on that it's cool!).

NOTES: I imagine it possible through having a config file in which scripts are configured (absolute path is provided) and to load them using this stuff and either cast Object to Runnable interface and trigger what I need or to invokeMethod(...) . But have no idea if it can be done easier (there should be a way, cause it looks all too clumsy). I also cant think of a way to handle file naming issue and multiple classes in one file issue.

PS: Such long description might cause misunderstanding so please comment on vague parts.

Answer 1

I think you need to know all classes implementing an interface. Find Java classes implementing an interface may be of interest to you.

Answer 2

The option to have a config file in which script's absolute paths are written is good and proved to be a working solution. You'll have to deal with class loading of whatever is not visible in the app class loader. In particular you'll have to deal with annotation based POJO serialization problems. Singleton of Runnable loader is a good practice.