> Is there a way to cut out the middle man?
> and just call The fortran directly?
That would require to have a fortran compiler with a compatible
calling convention and certain extensions allowing to make us of the
dynamic memory management used by the JNI C API. Your chances to find
something like this are slim. Your best bet would be g77 in
combination with gcj, and changing to the GNU's non-standard CNI
calling interface.
Alternatively, try another middleman. E.g. JNative, JNA, Nlink, jawin,
j-interop, JNIEasy, J/Direct, NoodleGlue, JNIWrapper, SWIG or whatever
is currently on the market (talk about re-inventing the wheel ...).
Some of these tools might be dead these days.
These are tools made to avoid having to write C/C++ JNI wrapper code
when calling existing functions. Either by generating the code for
you, or by providing a dynamic invocation interface. You could try to
build your fortran code into a DLL and then try to invoke fortran
functions in the DLL by using one of these tools.
Be warned, however. JNI is not very fast, an dynamically invoking
function via some tool and JNI is even slower.