Only way i can think of is to read  it byte for byte and then write
it. Or line for line, but i haven't really tried that.

javax.comm API use Java stream style when write  to and read  from serial
port. Off course, you can get input stream of file  to be sent, then write
it to output stream of serial port  connection.

I can send  a file  through the COM Port...
but i have another question !
how could I control the flow of data
I sent a file but i lost some of the data !

I am new to this solution, like very interesting...

just curious how u determine the connection to the serial port...for example
how do sent the file  to serial port  that is connected to a PDA cradle?

No experience in this...Just curious...