DataSourceInitializedEvent picks wrong datasource

[m-kay]

With spring boot 2.1.x the DataSourceInitializedEvent picks the wrong datasource again because the property to get the datasource from the EntityManagerFactory changed to hibernate.connection.datasource compared to javax.persistence.nonJtaDataSource used in the fix for #8296.

As a workaround one can fix this by passing the legacy property javax.persistence.nonJtaDataSource to the EntityManagerFactoryBuilder with the correct datasource. I have created a minimal example with everything needed to initialize two datasources at https://github.com/m-kay/spring-boot-init-two-datasources and you can see the fix in FirstDbConfigline 84 and SecondDbConfig line 83. I had to create my own DataSourceInitializer which executes init scripts after the event is fired for my second datasource, since the defaults only work with a single datasource.

[philwebb]

Thanks for the sample application @m-kay. I think that this might be a bug in recent Hibernate versions. I've raise HHH-13432 to see if the Hibernate team agree. I'll close this issue for now, but if it turns out to be a bug on our side we'll reopen it.

[philwebb]

Turns out we're relying on something that isn't defined in the spec

I’m not aware that the spec says this should be supported (accessing “config settings” defined outside its properties block). It is not tested in the TCK.

I think the Hibernate team are going to change their code, but we should also look if there's something we can do locally.

[philwebb]

We're unfortunately very light on tests for DataSourceInitializedPublisher but the I tried the sample application with the fix and it appears to work.