I just begin to learn ejb, and have questions about ejb design.Is there one session bean as interface with several helper calss, or many session beans co-operated to finish a task? In my opion, if one session bean only used in the server side and without synchronization requirement, it should be replaced by a helper class to improve performance. Is that right?

In order to understand whether to use SLSB or not you should keep in mind that SLSB gives you:

o Isolation of interface and implementation through JNDI lookups
o Automatic transactional context
o Automatic handling of concurrency
o Automatic scalability
o Clustering support

If you do not need any of that features, using SLSB would be overkill and using a plain Java helper class instead would definitely make sense.

HTH

Regards,

Slava Imeshev

nice rules, thanks!