Re: [activemq-dev] Re: [Springframework-developer] Re: [activemq-dev] Re: message driven POJOs, a lightweight JCA container available

[<jas...@ma...>]

On 27 Oct 2004, at 20:11, Eugene Kuleshov wrote:
> James Strachan wrote:
>
>>> I think Eugene has a point.
>>>
>>> The work manager isn't the problem, it's integrating message 
>>> delivery to mdbs without container support.  This is going to be 
>>> even more unlikely to work for CMT mdbs.
>>>
>>> If you want to use your spring psuedo-mdbs inside a j2ee container, 
>>> there's still the problem of transactional message delivery.  
>>> There's no standard way to find the TM and even if you get it I 
>>> would investigate extensively before thinking that using it directly 
>>> will give you the correct semantics.
>> Agreed - though we're delegating to Spring for this issue....
>
>   By the way, there was a huge discussion related to CMT and Spring 
> manged transaction and as far as I remember everybody agreed that in 
> general it is a bad idea to mix those.

If in doubt there's always MDBs


>>> For instance,  in Geronimo I'm fairly sure it would not since we 
>>> wrap the JTA objects with more context.
>>>
>>> So this spring thing looks pretty cool but is unlikely to be of much 
>>> use in j2ee non 1.4 containers.  But, why not use a j2ee 1.4 
>>> container anyway?:-)
>> Exactly!
>
>   Can you guys remind me all J2EE 1.4 containers that already released 
> and how long ago? :-)

:)


>> If you're in a J2ee 1.4 container, you might was well just deploy 
>> MDBs. This is more for cases where you're not in a J2EE container, 
>> such as you're using just Tomcat + Spring and want the effect of MDBs 
>> coupled with the dependency injection of Spring and using Spring as 
>> the transaction manager (which has hooks to JTA or could plug in to 
>> Geronimo's TM etc).
>
>   By the way, speaking about Tomkat + Spring, I wonder where you going 
> to get transaction manager. If I'm not mistaken Spring only provide 
> delegators, so coordination between JMS and JDBC tx resources could be 
> an issue.

JOTM? Folks have used that successfully in Tomcat & Jetty.


>> If you need the J2EE features, just use a J2EE container!
>
>   That bring me back to 1.3 container. :-)

:)

>   So, personally I'm ok with MDB's, maybe except the fact that you 
> can't really create consumers on the fly using some standard way (not 
> counting container-specific JMX magic).

Agreed; folks could create 'message driven pojos' containers in J2EE 
app servers using container specific hooks, to create the POJOs using 
Spring. e.g. adding this to Geronimo would be pretty easy.

Another idea to reuse legacy containers would be to just write a MDB 
wrapper which delegated to Spring to create the POJO. While its more 
painful to configure, it would allow you to reuse the legacy MDB 
infrastructure and use Spring for Dependency Injection.

James
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