It's not as simple as using c/c++ and the win32 api - it's been a while since Sun/Oracle have supported a Java serial communications API on Windows. But it can be done if you track down the necessary drivers/libraries - try starting with
RXTX
If you're not constrained to use Java, it's probably simpler/faster to use the win32 api with c/c++, or the serialport api in .NET
Hope that helps....feel free to PM me if questions
- Ron
Team #2607 controls mentor