Two other possibilities.

One is to execute some handy standalone spellchecker program like Aspell (or
whatever) as an external process reading from stdin and writing to stdout.
That architecture works a lot better than you'd imagine -- especially if you
can avoid Cygwin-based ports of Unix-y programs to Windows (native ports are
fine, it's just that Cygwin add a lot to the startup time).  Even if you don't
stick with that forever, it should take no more than a few minutes to hack
together a first cut at a package using that approach, which would allow you to
focus on more pressing matters (I'm sure you have many such ;-)

A more complex approach, but not difficult at all if you a re comfortable with
JNI, would be to use it to connect Java and the Hunspell library.
   http://hunspell.sourceforge.net/
The specific advantage of Hunspell is that it's used in OpenOffice, so their
language files are widely available.  I have done this myself (not in Java, but
the idea's the same) and there were no great difficulties except (as ever) for
the lack of documentation.  In fact the only real source of confusion is that
there are a buch of undocumented/underdocumented functions in the library for
morphological analysis -- the thing to do is just to ignore them.

   -- chris