If this is going to be you own implementation, jaas  is what you need. We had this discussion before under title of "Security" in the list before, may be if you have a quick look at history of that discussion you find  it helpful.

So many samples  are out there which you can use i.e.
developers.sun.com/.../bioauthentication.html

here is also a sample code  for you

java.sun.com/.../index.html