"Network configuration" covers an awful lot of territory
Factor in the possible #/platforms (different flavors/versions of Linux; possibly Windows/different versions of Windows; who knows: maybe MacOS other other Linux) ... and the search space grows even larger.
And, as I'm sure you know, most "network configuration" involves a) editing configuration files, and b) running binary executables. There is seldom a "programming API" of any kind available, much less a programming API for Java.
So yes, whatever it is you want to do, you can probably do it from a Java program. But, depending on the specific task(s) you had in mind, it's probably going to involve "System.Runtime.exec()". Just like C/C++ would probably involve "system()" or "popen()".
IMHO .. PSM