Here are the keywords for your research on google: BlazeDS,
Live Cycle Data Services, RemoteObject!
Basically, you need a service side infrastructure that would
expose your pojos as callable objects and RemoteObject on the Flex
client to call these pojos.
This is, of course, an alternative to you JSP, Strtus Action
or some other Java server side code creating XML and writing it to
the HttpResponse and you'd use HttpService class to call such
resources.
ATTA