GIYF

http://swik.net/Rails+Struts

Check http://www.headius.com/jrubywiki/index.php/Rails_Integration

Arne

It all depends on what you favor as development methodologies
and programming practices.

At the programming level, for some people dynamic typing is
important while for others dynamic typing is big no-no (and
hence Ruby / JRuby is a big no-no).

I simply love the productivity gain that I get thanks to
my beloved Java IDE and I know that I'd waste lots of time
tracing down errors that my IDE wouldn't catch if I wasn't
using a language offering the same typing properties as
Java does.

Some feel more productive using Ruby and consider Java
to be an ugly piece of crap while some others consider
that for big projects Java is way more manageable than
Ruby.

YMMV.

Last time I checked that said, say, GMail, Walmart and
eBay were running on Java, not on Ruby.

The fact that Ruby is slow and that it knows nothing
about Unicode may have something to do with the fact
that it is not often choosed for serious applications ;)

So it may comes down to: for small to medium english-only
websites Ruby may be more productive while for real-world
projects (or even small projects needing to manipulate lots
of Unicode strings) Java may be more suitable.

Don't forget that a company will supposedly have more
programmers that know Java than Ruby.

AJAX is asynchronous JavaScript on the client side.
JavaScript is a general purpose language but it is mostly
used as a client-side language, living in a sandbox in the
user's browser.

Here you're talking about using Ruby (on Rails) or
JRuby / Rails as a server-side technology.

It's comparing apples to oranges.

Just as you can serve AJAX apps to a user's browser
from a Java-backed webserver you can serve AJAX apps
to a user's browser from a Ruby (or JRuby) backed
webserver.

Now which one is easier is an open discussion (I'm
personally using Java / GWT which saves me from
writing JavaScript :)