Spring transaction management is that it allows you to declaratively or programmatically define transactions around methods, without the need for a container (it uses AOP to insert the transactional code around the service methods at runtime). One can therefore test transactional methods in a service layer in plain old Junit, without having any app server running. Thus the applicaion is transactionally aware, without the need for CMTs and (hurrah) - no EJBs.
So getting back to the original question, which basically asked about dynamically creating datasources, which for the sake of argument were used by data access code that in turn was used by service methods I would recommend doing the following:
buy the book, "Spring in action" and get up to speed on Spring. Chapter 4 shows you how to wire datasources to data access objects, chapter 5 shows you how to introduce transactions. Once you've got to that stage you'll know how Spring works and how do what you want in a static, non-dynamic way. Then pop over to the Spring forums and read these threads:
http://forum.springframework.org/showthread.php?t=21925&highlight=dynamic+datasource
http://forum.springframework.org/showthread.php?t=19887&highlight=dynamic+datasource
which tells you all you need to know about doing it dynamically
I can't recommend Spring enough for any Java programmer who hasn't used it, it creates cleaner, more decoupled, easier to test code and gives you loads of help for jdbc, hibernate, transactions, security, JSPs and so on.
I apologise for veering away from Geronimo, but on the application I am working on at the moment, we are doing something very similar to the above, and need the application to run in both Geronimo and Websphere (full version, not CE), so we have to make our code app server independent.
| David Jencks <[EMAIL PROTECTED]>
27/06/2006 16:55
|
To: [email protected] cc: Subject: Re: Dynamically creating datasources |
On Jun 27, 2006, at 3:05 AM, [EMAIL PROTECTED] wrote:
"That would be app server independent, but it would also preclude any container managed transaction features such as use of UserTransaction or CMT ejbs. If you don't need any features like these this might well be your simplest solution."
I neglected to point out that I am using Spring's AOP techniques to wrap my services in transactions anyway, so I have transactional support without the need for containers or EJBs. I know this is possibly sidestepping the issue, but that is exactly what I wanted to do ;-)
I'm not really familiar with dbcp, but my impression is that it is not jta-aware. I'm also not that familiar with spring tx management but again I think that without a jta-aware pooling implementation hooked up to a jta (or jts) tm no container managed transactions will work. In other words, I greatly doubt that what you are doing will work. I'm happy to be proved wrong.
thanks
david jencks
Target
www.targetgroup.net
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