Make nxt 2.0 robot maze mapper.

I have nxt 2.0 mindstorm, i want to make robot that will go through maze and map the maze. I have made him to avoid the obtacles but i dont know how to map and see the result in pc. Things that i want to be done: 1. Java program about the robot maze mapper that will find the end in the maze and it will map where it goes. 2. Help to setup and make it work!