simply pass an interface (callback implementation) to your runnable like this
interface Callback {
void callback(); // would be in any signature
}
class MyThread implements Runnable {
Callback c;
public MyThread(Callback c) {
this.c = c;
}
public void run() {
// some work
this.c.callback(); // callback
}
}
and a simple tutorial about everything you need about thread here