How store java.sql.Connection in Statefull SessionBean ? 2003-11-25 - By Stefan Frank
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Hi Paolo,
ah, I see: 3) makes things difficult&this is where the need to acquire
and keep the connection comes from. Correct me if I'm wrong, but does
client need to control the commit/rollback really on the CONNECTION?!
Maybe things will become easier when you just map the commit/rollback on
the BusinessObjects: Gather the Objects that need to be stored in the
StatefulSessionBean, if user commits, acquire a connection from the
server, store, commit and release the connection, if the User wants to
rollback, just discard the stored Objects. Activating/passivating will
become less troublesome, if you make sure that all your objects are
serializable - this way you avoid locking database-Ressources. If your
Client crashes and never commits your objects, the objects in your bean
will be garbage-collected on timeout, so no ressources will be locked.
Does this solve your problem?!
cheers
stf
Paolo Bacco wrote:
> Hi Stefan,
> Application specs are:
> 1- client is an applet.
> 2- EjB acts as a Session Facade (stores client state) and has all business
> methods client needs.
> 3- Applet require commit /rollback capabilities to SessionBean.
> 4- EjB container supports only Ejb1.0 specs.
>
> Thanks.
> Paolo
>
>
> -- -- Original Message -- --
> From: "Stefan Frank" <s.frank@(protected)>
> To: <J2EEPATTERNS-INTEREST@(protected)>
> Sent: Monday, November 24, 2003 4:12 PM
> Subject: Re: How store java.sql.Connection  in Statefull SessionBean ?
>
>
>
>>Why do you have a need for storing the Connection?! Storing and Reusing
>>the Connection is not such a good idea if you have transactions that
>>cross the boundaries of you StatefulSessionBean, with demarcations
>>declared in your deployment-desriptors - which is one of the mayor
>>reasons to have SessionBeans instead of a simple Class. Usually the
>>Connection should be managed by the Container. The Container is also
>>responsible for pooling the connection, so that you will not see any
>>performance-penalties with this approach. Or is there a specififc reason
>>why you want to acquire, manage and store the Connection inside the
>>Stateful Session Bean?!
>>
>>Paolo Bacco wrote:
>>
>>>Hi all,
>>>I deal with an old J2EE container (OAS), EJB 1.0 specs compliant, which
>>>allows to create only statefull Session Beans.
>>>I tried to create a simple application where each session bean holds its
>>>own connection to database (so it performs commit/rollback operation
>>>according client requests).
>>>My question is how manage Connection in my Statefull Bean.
>>>I know that java.sql.Connection has to be declared as transient member,
>>>because Session Bean could be passivated by container, so how could I
>>>prevent loosing connection?
>>>I guess that a solution is to give that connection to another
>>>object in EjbPassivate() method and acquire it in EjbActivate(), but
>>>neither I can store any object in EjbSessionContext, nor I can store
>>>Connection in JNDI service (because is not serializable again).
>>>Someone can help me?
>>>
>>>Thanks,
>>>Paolo Bacco - Italy
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