Options for Java Middle-Tier of an RIA Application

Choice of Standard/Framework
Here's my best option or two for each area:

• Persistence:
  
  
  • JPA. Use implementation-specific annotations only where unavoidable, and mark them in a way that will allow you to find all of them easily.
   
• Transaction Management: EJB 3.1

• Dependency Injection: EJB 3.1

• Security: EJB 3.1

• Exposing required web services:EJB 3.1

• AOP: EJB 3.1 if their support for AOP is sufficient for you. Otherwise: Spring

• Other:
  
  
  • Singletons: EJB 3.1

Providers

• JPA: I use Hibernate, but the whole advantage of JPA is, that which provider you use is much less important than it used to be.
• Application Server: Glassfish 3. It does support EJB 3.1.