DataSourceBuilder has a number of aliases to accommodate for small changes in API. For instance, Hikari has a jdbc-url rather than the more common url property so we have a mapping for that. This mapping is useless if the DataSource we configure isn't using Hikari.
So far we got away with it, but adding support for Oracle UCP means we need to add yet another alias that's actually a valid property for DBCP2 (yet referring to something completely different).
Comment From: snicoll
Taking a step back, it's rather ConfigurationPropertyNameAliases that attempts to bind to any alias that is configured irrespective to the fact that the "main property" has been bound.
Comment From: snicoll
To reproduce quickly the issue, you need to patch DataSourceBuilder as follows and the run CommonsDbcp2DataSourcePoolMetadataTests. Both setDriverClassName and setConnectionFactoryClassName will be invoked because those two properties are present in the environment.
Comment From: philwebb
Unfortunately we might not be able to fix this one by changing the alias logic. The alias feature is part of ConfigurationPropertySource and the Binder isn't aware of it. I think we'll need to go back to only adding aliases when we know the DataSource type supports them.
Comment From: fabio-grassi-gbs
I committed a change in pull request #23403 that doesn't use ConfigurationPropertySource in favour of plain BeanWrapper plus some custom logic local to DataSourceBuilder. It's not super-clean, but does the job.
Comment From: snicoll
@fabio-grassi-gbs I saw that, that's an interesting approach. I think we'd prefer something more declarative and I've been working on that Friday.
Comment From: snicoll
Unfortunately, we broke support for the OracleDataSource where an alias is applied with a type that does not implement DataSource. I'll reuse this issue to fix that as we haven't released this feature in a milestone yet.
Comment From: snicoll
Taking that back, that's rather a type safety issue as we have a test to cover that use case. Looking at the hierarchy, I'll settle for OracleDataSource anyway.
Comment From: snicoll
I've refined things in ef2fee2