<p>I am embarking on a new RIA project with Java on the backend. I'm the only developer, and the app is a line-of-business application. My current stack looks like this:</p>

<p>MySQL || Spring(JdbcTemplate for data access) || BlazeDS (remoting) || Flex(Cairngorm)</p>

<p>My question is: what changes can I make to improve productivity? Manually coding SQL, server-side entity objects, client-side value objects and all the Cairngorm stuff is obviously a drag, but I'm not sure what higher-level frameworks to introduce.</p>

<p>What Flex/Java stack has served you well? </p>

Manually coding SQL
Hibernate
is an option to cut this out.
One thing that may be of interest is Grails with the available Flex Plugin. It's built on Spring, Hibernate and BlazeDS, so it's all there for you. It was unbelieveably easy to get it remoting stored objects and responding to AMF calls. I was using this and then moved over to a RESTful E4X implementation as I found it a lot easier to debug and tweak as I could inspect the server output in a browser and have tighter control over exactly what I returned to my Flex app (lazy loading problems in collections using BlazeDS were a headache at times).
Here is a quick tutorial showing how easy the whole Grails + Flex Plugin stack is:
BlazeDS  in Grails