Giving focus to the program

Question

I need to make a Java program give focus to itself.
I'm thinking of a thread that would give focus to the program every second.
But I dont know how to make it "give focus to this program on the computer". With my searches, I can only find about giving focus to a component of the program, not the program in the computer/os
The program will run in Windows, so something platform specific would be ok.
Or any other way to make this Java program regain focus automatically about every second.

Answer 1

In brief, I need to do it for a barcode system. It's somewhat complicated, the commerce system uses php and is online. In this system, I added an applet which recieves events from a local program (the one I want to auto-focus).
This local program recieves events from the barcode scanner. But a barcode scanner is stupid, and considered like a keyboard for the computer, so a program must be in focus to recieve the events. The best solution I could think of is to make this local program always takes the focus. The interface of this program would be small (or no interface at al).
All of this system is done and works correctly. The only piece of this puzzle that is missing is having the local program always recieve events from the scanner.
The computer that will run it is the "cash regitster" computer for the store, so having this local program always gaining focus is correct. And if needed, this "auto-focus" could be deactivated while the computer is needed for other things.
So the real point is maning sure the local program gains focus about every second so it recieves the events of the scanner, since the scanner is considered like a keyboard.