You can use the sun jdbc-odbc bridge for accessing both Excel and Microsoft Access files via jdbc. However, it requires you have the appropriate ODBC drivers installed on your system, and the files
have to be on the same machine. To access files on another machine,
you can use RMI-JDBC bridge(
http://java.sun.com/products/jdbc/faq.html#5,
http://rmijdbc.objectweb.org/Access/access.html)
You can use xlsql [
https://xlsql.dev.java.net/ ] for purely jdbc
access, but it requires you to also have hypersonic sql available.
Basically, it converts excel files into a hypersonic database (in-memory
i believe). So, when you setup your dialect, have it use the one
for hypersonic.
As for MS Access, I'm not sure what pure java drivers (type 4) are
available, but I'm sure there's a commercial one out there (though I'm
not sure anyone would use access in production with a j2ee application
anyway, so there may not be a need)