I might need some explaining of stuff I haven't found answers for - neither here nor in javadoc or in the spec... (at least until now)
I am building an application which will have to execute Javascript code, with the help of JSR 223. I am interacting with the JS world through a couple of JS objects which are available to me through global variables. This is why I mainly use Invocable.invokeMethod for my calls to JS. (And I create these objects by calling JS constructors through Invocable.invokeFunction and set the returned object in a JS var with ScriptEngine.put(). The actual code I read in with ScriptEngine.eval())
Now this is a server application, so CPU footprint and execution speed are important. So I discovered Compilable. Which brings me to my first question: Why does this interface exist at all? Why don't the different script engines do this internally and transparently?
Ok, but back to the assumption that I have to use Compilable. And instead of reading my JS sources with ScriptEngine.eval I would use Compilable.compile(). Which would return a CompiledScript to me. Which has an interface that only offers eval methods. But not anything which resembles the API of Invocable.
So how do I get back from my CompiledScript to Invocable? I still want to use that, the API gives me a nice abstraction! :-)
Anybody can help me out with that? (This is all happening on Java 7 with Rhino. But of course migration to Java 8 - meaning Nashorn - is coming soon so I will have to deal with both engines.)
Thanks a lot, Torben
Update: Ok, now I just discovered that I overlooked some sections in the spec, the ones about Invocable and Compilable. So it seems like I will already get the benefit of compilation when using Invocable (why didn't they mention this in the javadoc?!).
But then I still have a question: How do I import my source code? Will Invocable do a quasi-compilation of my code if I import it with ScriptEngine.eval?