Following feedback and discussions I've now taken the proposals to improve JMS MDBs to the next stage, which is to draft
a new chapter for the JMS specification. This is chapter 16 "JMS Message-driven beans".
This can be downloaded from
https://java.net/downloads/jms-spec/JMS%202.1/JMS21_EDR1_RC1_CH16.pdf
I've updated the Javadocs to match; these are in the same place as before,
https://jms-spec.java.net/2.1-SNAPSHOT/apidocs/
(Let me know if you have any trouble accessing this)
The main change since version 2 is to replace a single @JMSListener annotation with three separate annotations,
@JMSQueueListener, @JMSDurableTopicListener and @JMSNonDurableTopicListener. When I floated this earlier everyone who
responded seemed in favour.
I've adopted the term "flexible JMS MDBs" to describe this new feature. Any better suggestions?
In addition I have pored over the detailed wording to try to make it as precise and unambiguous as possible. I've
attempted to describe the required behaviour after an exception is thrown or a conversion error is encountered to be
similar to the (rather vague) wording of the existing spec.
I've inserted notes to say that a number of aspects still need further work. These are:
* Moving the description of "classic JMS MDBs" from the EJB specification to JMS 2.1
* Seeking changes to the EJB specification to remove the need to implement the JMSMessageDrivenBean marker interface
* Deciding whether or not a JMS MDB should be allowed to have multiple callback methods
* How to handle conversion errors when trying to set method parameters
* How to handle checked exceptions thrown by the callback method
At a future stage we also need to consider
* Extending this to allow batch delivery (as proposed by Clebert)
* Defining redelivery behaviour if the MDB throws an exception (as proposed in the original JSR): redelivery limits,
dead message queues etc.
Please take a look and let me know what you think.
Thanks,
Nigel