I'm sure Rails would be less code and quicker to production.
That's not to say that it can't be done quickly in Spring - Java.
The whole 15 min blog thing is a good example of fast Rails, it's also a good example of non production ready i.e. maintainable and extendable, rails.
Would be nice to see some side by side code of Rails and Java/Spring doing roughly the same things, both written by people experienced in those technology stacks. These debates aren't very useful without code to look at.