Well, I am planning to fetch the status of the GPIO pins via snmp. Like PIN x and y do have contact and then switching a 3rd one and for monitoring giving that info out via snmp.
I did that in VB6 on my own (listening on a snmp request, extracting the OID and according to that OID reading the values, packing a snmp reply and send it back). Sure not on a Pi but on a Windows server (without using the Windows SNMP capability).
A SNMP Agent out there may could be used, but this is a issue not related to B4J on a PI, I assume.