Only reading the code once, it appears to me to be getting user home directory. To get current dir would we not:
String currentDir = new File(".");
And, as well, working dir and current dir may be somewhat misleading for inexperienced coders. Say runnable Java code with a properly written main() and so on is in /dir/dir/program.class and the code does File fidelus = new File("../dir/dir/drivel.dat"); or opens several files or tries to do some beginner blunder or ..... ( unthought of work goes here )
Where did the concept of working dir go?....perhaps concept of working directory is of limited scope. If os supports multiple file handles open, concept of working directory is archaic.