To do this you need a server program
on each of the computers on the local network.
This server program will respond to a client request
from your program and return the information you
need. There a a number of distributed file system
protocols, and some operating systems have some
of these DFSs built-in, obviating the need for you to
write and deploy your own server. You should first
figure out whether you are going to use an existing
DFS, what protocol that DFS uses, and whether there
are any third-party Java classes that will allow you to
communicate using the protocol of that DFS. The
FAQ will help, if you read it.