How to pass a number from the button event handler to another class in which it will be processed and return it back?

Question

Java

How to pass a number from the button event handler to another class in which it will be processed and return it back?

Answer 1

In the button event handler:
- take a number
- pass it to another class
- wait until it is processed
- ...
- PROFIT!!!1
Excuse me, but what a question - such an answer.