Add Lifecycle extension

[mp911de]

Lifecycle allows Connections to be notified before and after their usage.

[elefeint]

This is great. It might make sense for other objects, such as ConnectionFactory instances, too (I am always looking for better ways to clean up factory-global state).

[mp911de]

For ConnectionFactory we have Closeable that can be implemented to dispose any lingering resources. That seems the better fit for a connection factory than the Lifecycle interface.

[Michael-A-McMahon]

Thanks for adding this. Would it make sense to declare Connection as extending Lifecycle? The specification text suggests that this should be the case.

[mp911de]

I'm reluctant to add that to the Connection hierarchy as lifecycle methods are concerning an extremely small audience. The single Pool implementation can perform an additional instanceof check and so far only a single driver would make use of this extension.

I understood that part of the issue of the JDBC variant of these methods is that application users of the JDBC Connection are not sure what to do with these methods. Keeping these methods in a less prominent place should not lead to issues seen on the JDBC side.

[Michael-A-McMahon]

Right, this makes sense. Because these methods are only used by connection pools, it doesn't benefit the application programmer to see them on Connection objects. In fact, we probably want the application programmers to ignore these methods. I think a pool implementation might want to assume that it has control over the lifecycle, and that application code is not going to be calling these methods as well.
Thanks for explaining.