What exactly happens when you have final values and inner classes in a method ?

Programmer Question

I have came across many situation where I needed to pass value to an other thread and I founded out that I could do it this way, but I have been wondering how is it working ?

public void method() {
    final EventHandler handle = someReference;

    Thread thread = new Thread() {
        public void run() {
            handle.onEvent();
        }
    };

    thread.start();
}

Edit: Just realise my question wasn't exactly pointing toward what I wanted to know. It's more "how" it works rather then "why".

Find the answer here