javax.usb

One day I'll work out whether a lot of my problems aren't coming from having something non-standard about my desktop PC that means a lot of downloaded software doesn't do quite what it says on the label. Once I got everything installed from this package, I couldn't get past a very annoying bug:

javax.usb.UsbException: Properties file javax.usb.properties not found

The javax.usb.properties file was in my java install directory, located under jre/lib/ext. The very terse instructions that are available for javax.usb tell you the properties file must be in the CLASSPATH. As I got more desperate, I coped javax.usb.properties to every java-related directory I could think of. There must have been 20 copies of the file by the time I gave up. Still the same problem. The problem manifests itself when the UsbHostManager class does its initial setup, in the setupProperties method:

InputStream i = ClassLoader.getSystemResourceAsStream(JAVAX_USB_PROPERTIES_FILE);

The javax.usb classes are all loaded from a jar file located in jre/lib/ext, and putting the javax.usb.properties file in the same jar file solved the problem for me. You can do it with "jar -uvf jsr80.jar -C /path/to/properties/file javax.usb.properties". The -C takes care of the path to the properties file. Without the -C option, javax.usb.properties is added to the jar file but includes the path information on your system.

Back to work. Well, back to trying to work out why my tools don't work!