Alternative to a Reflection-Based Event System?

Alternative to a Reflection-Based Event System?

Currently I'm creating a mod for a game. I am using a reflection-based
event system at the moment. I want to get rid of the system because
frankly.. reflection is bad. What this reflection-based event system did
however would do something like this:
class Mod extends ModBase implements EventListener{
@EventHandler
void runCode(Event event){ // When a Event object is created...
}
}
I still want to use an event system, however, I just don't want it to use
reflection. Does anyone have an suggestions?