dbus-java and org.freedesktop.UDisks.Device

[andy]

Hello,

I would like to use dbus-java to find information about a disc insert.
To do so, I need to listen for the DriveChanged signal, retrieve the
device and examine properties.  So far, I've managed to register for the
signal, but I am not able to create a UDisks.Device interface or
otherwise retrieve information for the device.

DBusConnection conn
=DBusConnection.getConnection(DBusConnection.SYSTEM);
conn.addSigHandler(UDisks.DeviceChanged.class, new
DBusSigHandler<UDisks.DeviceChanged>() {
  @Override
  public void handle(
    UDisks.DeviceChanged changed) {
     Object dev = changed.getParameters()[0];
     // at this point, dev is a $Proxy2 object.
     System.out.println(dev);
  }
}

What can I do with dev?  I've tried to use CreateInterface to create a
org.freedesktop.UDisks.Device for /org/freedesktop/UDisks/devices/sr1,
but that fails with a:

ERROR: Failure in DBus Communications: The name
org.freedesktop.UDisks.Device was not provided by any .service files

How can I access the information about the device?

Right now, my hacky solution to this problem is to parse the dev
toString() and create a hal query to submit to hal-get-property.  It's a
mess, and I'd rather do it all with dbus.

TIA, and if this is not the correct list for java related queries,
please point me in the right direction.

Andy