No other choice but to precede the names
with a digit like 0.first_name, 1.last_name, etc...

if you have more than 10 parameters,
make it a double digit like 00.first_name, 01.last_name

When you have done this, load the
enumeration inside a Collection implementation, and do Collections.sort().

You will then have them in the right order.

NOTE: the Servlet 2.3 specs can provide
you with a request parameter Map which
allows you to skip the extraction of the Enumeration.