The javax.usb stuff can depend a lot on the flavor of linux you are running, and your machine's configuration in general.
You should try downloading and running the example programs, here on sourceforge, on your machine. If those do not work, then you should assume you'll need to change either the configuration of your machine, or something about your runtime.
I was having some problems with this library, and got the following recommendations. This information may be quite outdated, but it may help point you in the right direction:
Once downloaded and built, you need to ensure that libjusb.so gets
copied over to $JAVA_HOME/jre/lib/i386, and that it has read and
evecute permissions for your user. Also ensure that you have the
usbdevfs virtual device mounted, and that your user has proper R/W
access to it.
Lastly, depending on what USB device you want to talk to, you may
need to disable hotplug (or at least blacklist any installed modules
that may also attempt to talk to your device). If the device already
has support in Linux, hotplug will load it's associated module and
give it exclusive I/O access before you can grab the device from jUSB.
The above quoted text is from Brad Barclay. Hope this helps.