question about available midi ports

[P5music]

Hi
I created a java midi application that can list and use all available midi ports.
It detects just "edirol interface" ports and "software sequencer"+"software wavetable synth" ports. These ports are not useful to communicate to other applications, like jack. In jack I see "midi through" port too, but it is not available in my application.
So I ask you how to have some further midi ports that are recognized by java, useful to send midi data to other applications.
thanks in advance