GPS Data Logger Software - BT747

Hi,

   I downloaded the source code of the project to try to understand how it is made the connection with the GPS. I need this java code for my master. However, reading the code I cannot understand how this work, I understood that the main classes for the connection is gps.connection.GPSrxtx and gps.connection.GPSPort but I cannot found how the port is openned and how I can get information from the GPS.