Strongly recommended.
On Thu, Sep 15, 2011 at 12:55 PM, reza_rahman_at_lycos.com <
reza_rahman_at_lycos.com> wrote:
> +1
>
>
> Sep 15, 2011 11:18:16 AM, jsr343-experts_at_jms-spec.java.net wrote:
>
> I'm returning to this issue which we discussed back in July. This was about
> improving the EJB specification to define
> more explicitly how a MDB that used JMS should be configured.
>
> This issue is being tracked using the following JIRA issue
> http://java.net/jira/browse/JMS_SPEC-30
>
> Here's what I originally wrote in the JIRA issue:
>
>
> ----------------------------------------------------------------------------------------------------------------------
>
> The EJB 3.1 spec is distinctly vague about how a MDB is defined. The
> relevant sections are 5.4.15, 5.4.16 and 5.4.17.1.
> The only activation config properties defined are acknowledgeMode (only
> used when transactions are bean-managed, and
> which must be either Auto-acknowledge or Dups-ok-acknowledge),
> messageSelector, destinationType (which must be must be
> either javax.jms.Queue or javax.jms.Topic) and subscriptionDurability
> (which must be either Durable or NonDurable). But
> it doesn't specify how the destination is defined or, when
> subscriptionDurability is Durable, how the subscription name
> and client identifier are defined.
>
> The JCA 1.6 spec has some additional guidance, at least for MDBs that use a
> resource adapter. Section B2 states that
> providers are "strongly encouraged" to provide the properties mentioned
> above and also destination, subscriptionName and
> clientId, with destination and destinationType as "required" properties.
>
> Whatever else we do, there seems to be a clear need to make these mandatory
> for JMS MDBs, whether or not they use JCA.
>
>
> ----------------------------------------------------------------------------------------------------------------------
>
> Following the discussion we had at the time, and the discussions I had with
> the EJB 3.2 spec lead, I would like to make
> some more specific proposals about clientId and subscriptionName. (I've
> also added this text to the JIRA issue, you may
> find that earier to read):
>
> I propose that we seek a change to the EJB 3.2 spec to add additional
> activation configuration properties "clientId" and
> "subscriptionName" for JMS message-driven beans
>
> Section 5.4 of the EJB 3.1 spec currently defines the the following
> activation configuration properties for JMS
> message-driven beans:
> acknowledgeMode (optional, default is AUTO_ACKNOWLEDGE)
> messageSelector (default is an empty String)
> destinationType (optional, no default)
> subscriptionDurability (default is NonDurable)
>
> This should be extended to define the following additional activation
> configuration properties:
>
> clientId
> subscriptionName
>
> These property names match those recommended in JCA 1.6.
>
> If set, clientId would be used to set clientId for the connection used by
> the MDB, and must be unique in accordance with
> JMS 1.1. There would be no default value. JMS 1.1 states that clientId must
> be set if a durable subscription is being
> used. However in JMS 2.0 (JMS_SPEC-39) this requirement would be removed
> and clientId would always be optional.
>
> If a durable subscription is being used, then JMS requires that
> subscriptionName be set. In the case of a MDB the
> subscriptionName is normally given a name unique to the MDB, to distinguish
> it from other MDBs and other applications
> subscribed to the same topic. It is therefore proposed that the EJB
> specification state that if the subscription is
> durable and subscriptionName is not set then the container will
> automatically set subscriptionName to the name of the MDB.
>
> As with the existing activation configuration properties for JMS
> message-driven beans defined in the EJB specification,
> clientId and subscriptionName could be specified either using the
> MessageDriven annotation
>
> @MessageDriven(activationConfig = {
> @ActivationConfigProperty(propertyName = "subscriptionDurability.",
> propertyValue = "Durable"),
> @ActivationConfigProperty(propertyName = "clientId", propertyValue =
> "MyMDB"),
> @ActivationConfigProperty(propertyName = "subscriptionName", propertyValue
> = "MySub")
> })
>
> or in ejb-jar.xml
>
> **
> **
> **
> **
> test.MyMDB**
> **
> **
> **subscriptionDurability**
> **Durable**
> **
> **
> **clientId**
> **MyMDB**
> **
> **
> **subscriptionName**
> **MySub
> **
> **
> **
> **
> **
> **
>
> Note: The issue of how to define the destination on which a JMS
> message-driven bean listens for messages will be
> considered separately, as this is a more complex topic. I'll be raising
> this separately.
>
>
> ------------------------------------------------------------------------------------------------------------------------
>
> As before, please let me know what you think. I'd like to establish
> agreement on this before raising if formally with
> the EJB EG.
>
> Nigel
>
>
>
>