2GioGio:
i think no matter what midi-hardware you will use.. it's drivers must supports general midi commands - standard commands for piano-keyboard and controllers (delay, pan, sustain and other knobs and sliders) events.
here is list of java midi classes:
and here - some beautiful examples:
good luck!
maybe you will be able to catch the midi structure - because it is not enough to know java, you will need to understood how midi works and play with controller and java at the same time! now i'm in deadlock.. 
R4Remoter v2 is fully written in .NET...
but how you plan to using midi as final result? i mean, technically - your remoter will recieve midi commands and then will send it to predefined scenes, like "modelmove.r4"? i come across with a sad fact - now i can hardly imaging usability of such multiknobbed midi-contollers.. there must be possibility to assign different scenes to piano-keys and to spread tweaks on controller's events for all currently rendered overlays (or only for the top one) with corresponding settweak blocks. maybe it will be better at first to think over the general using scheme? and have you run this midi-dumper from jsresources?
