You can invoke Fortran executable from Java like any other executable.

If you're in an environment that blends C with Fortran you can JNI to C
and call Fortran from there.

Invoking executables is less work than JNI.

Opalinski
opalpa@gmail.com
http://www.geocities.com/opalpaweb/

Keep it as simple as you possibly can.  If you can meet your requirements by
running the Fortran code as an external program and communicating with it via
either or both of files or stdin/stdout then do that.

   -- chris

OK, approaches.

(i) Have the Fortran program open a port and listen on it. Have the GUI
talk to the Fortran program on that port. You'll need to develop a
protocol, and parsing the protocol at both ends is an overhead, but it
saves an awful lot of tricky code. This is what I would do because it
looks easiest to me.

(ii) Use a Fortran compiler that compiles to JVM. University of Tenesse
have one called f2j, but I don't know how complete it is:
http://icl.cs.utk.edu/f2j/overview/index.html

(iii) Use the GNU C compiler to compile Fortran for the JVM. Sounds
bizarre, but should be possible as GCC has JVM as one of the processors it
supports and Fortran 77 as one of the languages it supports.

(iv) Craft glue code using JNI. This is the 'official' way of doing it, but
my guess is that it would quickly get dark and dirty.