I was just testing JCIFS for accessing Windows shares. It is very slow to the point of being completely unusable.
import jcifs.smb.*;
class First {
publ
If you can rely on "something else" to mount the share as a local directory for you, then reading files in the mounted share in Java should be portable.
Even if this is not a real solution, it would be worth trying this to see if you get a faster read rate. A significantly faster read rate might change your mind about the relative importance of portability. And if you don't get a significant speedup, then you'll know that JCIFS is not to blame ...