Are you not supposed to use SessionFactory.currentSession?

[okarmazin]

Consider the following snippet:

class MyController(
    private val sessionFactory: SessionFactory
) {

    @Transactional
    fun entrypoint(): Response {
        val session = sessionFactory.currentSession
        session.isDefaultReadOnly = true
        val whatever = session.use { session ->
            // ...
        }
        
        // ...
    }

I keep seeing WARN: Datasource '<default>': Closing open connection prior to commit when I do that.

Using a new session via sessionFactory.fromSession produces no such warning.

1. Shouldn't sessionFactory.currentSession return the session associated with the current @Transactional transaction? I thought it would after reading this: https://docs.jboss.org/hibernate/orm/current/userguide/html_single/Hibernate_User_Guide.html#session-per-request
2. Is it an error to use currentSession? The documentation at https://quarkus.io/guides/hibernate-orm says nothing about Hibernate sessions as far as I can see.
3. Is it preferred to inject a [Stateless]Session instead of SessionFactory? The Hibernate documentation also states that too many granular sessions are considered an anti-pattern, so I guess injecting a single Session into the controller would more cleanly map to the session-per-request pattern?

[quarkus-bot[bot]]

/cc @geoand (kotlin), @gsmet (hibernate-orm), @yrodiere (hibernate-orm)

[yrodiere]

Shouldn't sessionFactory.currentSession return the session associated with the current @transactional transaction? I thought it would after reading this: https://docs.jboss.org/hibernate/orm/current/userguide/html_single/Hibernate_User_Guide.html#session-per-request

It could, but in Quarkus I don't think it will. It really depends on your integration. You can request that as a feature if you want: https://github.com/quarkusio/quarkus/issues/new/choose

Is it an error to use currentSession?

It is since that feature isn't implemented.

Is it preferred to inject a [Stateless]Session instead of SessionFactory?

Yes.

The Hibernate documentation also states that too many granular sessions are considered an anti-pattern, so I guess injecting a single Session into the controller would more cleanly map to the session-per-request pattern?

Quarkus proxies sessions and creates one per transaction behind the scenes, which is the recommended way of doing things.

So, injecting is the way to go.

[okarmazin]

Thanks for your response, that clears things up.

Quarkus proxies sessions and creates one per transaction behind the scenes

To make sure I understand completely, in the following piece of code, f and g work with two different sessions due to Quarkus proxying the access to the session field?

class MyController(
    private val session: Session
) {
    @GET
    fun entrypoint(): Response {
        f()
        g()
    }
    
    @Transactional
    fun f() {
        session.doSomething
    }
    
    @Transactional
    fun g() {
        session.doSomethingElse
    }

[yrodiere]

Assuming the session is injected (I don't see an @Inject?), yes they would work with different sessions.