Are there any recommendation on the usage of SessionEventAdapter -> preLogin.
We have a few customizations on the TopLink sessions and an application can use one, all or any combinations of it.
All of them have a preLogin call.
Does calling preLogin multiple times effect performance?
Are there any best practices?
The preLogin event is commonly used for customizing a Session. You can also use a SessionCustomizer, which is probably better for customization, as it does not remain listening on the running Session.
There should be no issue with having multiple listeners, assuming you have no dependencies on the order they are run.