Question:
How do you change UNIX file permissions in Java? I've seen it done and I need to replicate it.
Answer:
There is no platform-independent way of changing
file permissions in Java. To do so, you either
have to write native code, or exec a local
program to do the work for you.
The way the programs you've seen have done it
is probably using the latter approach. For
example:
Runtime runtime = Runtime.getRuntime();
Process chmod;
chmod = runtime.exec("/bin/chmod 755 filename");
chmod.waitFor();
This approach is not recommended for programs
that must portable. But it is an acceptable
method if your program is only going to run on
Unix systems and you just need to get things
working.