>  -----Original Message-----
> From:         [EMAIL PROTECTED] 
> [mailto:[EMAIL PROTECTED]]  On Behalf Of Eric Kaplan
> Sent: Sunday, December 15, 2002 12:24 PM
> To:   Jboss-User
> Subject:      [JBoss-user] cmp mapping question
> 
> 
> 1. I've only seen cmp beans specify mapping to individual 
> data members (instance variables), not to keys in a map.  Is 
> there a technology available to do such a mapping?

If memory serves, keyed maps are the manner by which "Repositories" in ATG
Dynamo represent persistent data.  Based on the marketecture document at
http://www.atg.com/en/products/core_technology/data_anywhere.jhtml, they are
calling this "Data Anywhere Architecture" now.  After a fair bit of thought
about it back in the day, I started to wonder to myself why raw JDBC with
distributed cache invalidation wouldn't net the same thing, at least for SQL
persistence.

Craig McClanahan wrote something for Struts (and has since moved it into
Commons) called DynaBeans.  These are basically Maps that have strong dynamic
typing based on key, configured by XML descriptors via Digester (although I'm
sure they could be configured by the same manner in which Digester operates
by client code as well.)

It seems like a fusion of a CMP container around DynaBeans would be pretty
powerful.  I'd use it, one of my projects needs a dynamic store that is
similar to what Eric has described.  

Is it possible to synthesize a first-class Java Bean at runtime?  A proxy to
the DynaBean generated by BCEL maybe?  DynaBeans are almost there, but they
are accessed via bean->get("attribute").  If there was a way to generate a
bean at runtime that could be configured from a configuration descriptor to
respond to bean->getAttribute(), it might be possible to support both worlds
transparently with a substitute CMP container.  

Would this synthetic static typing buy anything?  Maybe in the end, it would
just be sugar...

-b


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