callbacks from CMP or caching layer

[mandrews-flarion]

hi folks,

i have an entity bean which has a String field containing xml. since i reference this bean often, i want to cache the parsed DOM locally in my application. of course, i can't store the DOM object in the bean since there are troublesome issues associated with persisting java objects directly

what i need then is a way for my application's own private cache of DOM objects to get notifications from jboss' CMP or caching layer, telling it when these beans have changed. then, after such notification, my application can flush its own cache of the DOM object corresponding to that particular bean.

questions:

(1) is there any way to get reference to such a jboss notification object from JMX or JNDI?

(2) if my whole approach seems problematic, please let me know.

thanks,
mike

[mandrews-flarion]

oh boy, silly me :-)

i realized the answer is clearly that i've got the wrong approach... i forgot that i can mix cmp and non-cmp fields in an entity bean, and that way i can have a non-cmp field provide the parsed xml DOM, storing it in an instance variable between invocations. then, the jboss CMP layer takes care of all the needed caching.

thanks!
mike

[mandrews-flarion]

hmmm... on second thought, i think i'm back to where i started from:

how would my non-cmp entity bean field know when to invalidate its privately stored preparsed DOM? some kind of callback from the CMP layer is the only way i can think of, so my bean can find out when one of its CMP fields was modified and then can reparse the CMP xml to DOM.

mike

[kevinconner]

Don't expose the CMP field in the interface, instead expose a method that sets the CMP field and your flag.

[kevinconner]

Forgot to add that you also need to set your flag in the ejbCreates, the ejbLoad and the ejbActivate.

[mandrews-flarion]

right ---

makes perfect sense; i forgot one could choose which CMP fields made it into the interfaces (i must have started to take my stock set or pattern of xdoclet tags for granted, and forgot the basics!).

thanks so much!
mike