Hi Staffan and Anders,
Here are a few portability issues I can think of:
1. CMP of entity beans is container-dependent (server side; solution: use
BMP or don't use entity beans).
2. Some containers provide container-specific properties to do things like:
i) caching entity bean state so that ejbLoad/ejbStore don't have to be
called on every transaction if not necessary (a performance enhancement), or
ii) avoid invocation through stubs (with concommitant serialization of
arguments), as required by the EJB spec, when invoker and invokee are in the
same VM. Both of these are server-side. Solution: don't use these
properties (and pay the performance penalty).
3. The details of getting an initial context with which to look up EJB
homes differs from container to container. Richard Monson-Haefel discusses
this point in his book Enterprise Java Beans (O'Reilly). This could be
client-side or server-side. Solution: encapsulate home lookup and initial
context access in an extracted method (see the Extract Method refactoring in
Martin Fowler's book Refactoing: Improving the Design of Existing Code).
See also: http://www.c2.com/cgi/wiki?ContainerIndependenceDiscussion
Best Regards,
Randy Stafford
Senior Architect
GemStoneProfessional Services
> -----Original Message-----
> From: Staffan Furn [SMTP:[EMAIL PROTECTED]]
> Sent: Thursday, March 23, 2000 3:39 AM
> To: [EMAIL PROTECTED]
> Subject: EJB portability
>
> Hi,
> We�re two students who are doing a project to earn our masters degree in
> informatics. We�re examining the EJB-architecture and we are focusing on
> cross-appserver portability problems. We would like to have some input
> from experienced EJB-developers in order to answer some of our main
> questions.
>
> Some of our questions are:
>
> What kind of portability problem exists today when developing and
> deploying EJB-applications?
> How can these problems be categorized? e.g. Client-side (the EJB-client),
> Server-side (the EJB
> component and its interaction with the container and databases)
> Possible solutions to these problems?
> What are the important questions that I should ask myself when my goal is
> to build portable EJB-components?
>
> with kind regards
>
> Staffan Furn and Anders Isacsson
>
> ==========================================================================
> =
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the
> body
> of the message "signoff EJB-INTEREST". For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".
===========================================================================
To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
of the message "signoff EJB-INTEREST". For general help, send email to
[EMAIL PROTECTED] and include in the body of the message "help".
