How to detect missing CAN devices from Java?

[fovea1959]

We are heavily using CAN this year, but our test chassis does not have any CAN Talons or a CAN PDB on it (yet).

If we deploy our CAN-Talon-using code to a RoboRIO that does not have CAN Talons present, the robot gets "stuttery"; the PWM-based drive system keeps cutting out. We commented out all the code to get data out of the PDB and Talons (we're doing a lot of data logging while we get things tuned), and things smoothed out. It *appears* the CAN Recieve timeouts are causing problems.

Is there a good way to determine in software if a CAN Talon or PDB is absent so that we can avoid the method calls that cause issues with missing hardware?

I know we can put in a compiled-in boolean, jumper detect, or dashboard toggle to avoid the code, but would really like to just have the software self-configure....