How to use JAVA access Serial Port connecting to POS system?

[GARY CHAN]

Hello,

I am a newbie on writing interface program, my name's GARY from HK.~

I have the spec. of the POS system. That system can be connected to PC
using serial port RS232. Something like boud rate, control signals
(e.g. 00x0F) and message format can be foud in the spec.

However, I have no exp. on writing interface program at all.

Could anyone give me tips on writing this kind of interface program?
I just know that i can use the JavaComm ext. package. but how to
write? what steps i should take and plan?

Thanks Very Very much !