Are there any examples of using http4k with an `AutoCloseable` thing like a database client that nee...

# http4k

[Nezteb]

Are there any examples of using http4k with an AutoCloseable thing like a database client that needs to be opened upon request and closed once the response is sent? Or using try-with-resources?

[s4nchez]

Not that I'm aware of. The normal approach I see is managing the db resource in the boundary of the service/repository, rather than at the handler level.

[s4nchez]

The pattern I recommend is using handlers primarily to extract/inject data from/into Request/Response, but rely on other domain abstractions to deal with other concerns.

[s4nchez]

The "http as boundary of everything" is a bit of an anti-pattern in my view.

[Nezteb]

True; I’m going off of this. https://github.com/http4k/http4k-by-example/blob/master/src/test/kotlin/env/FakeUserDirectory.kt#L32

Right now I’m porting an app that was already built over to http4k to prove it out for some architects.

[Nezteb]

And it unfortunately is very coupled to the DB implementation

[s4nchez]

You can replace private val users = mutableMapOf<Id, User>() with a class that deals with set/get/delete of users with the db resource management encapsulated in it.

[s4nchez]

You can even make it "look" like a map by using operator functions (i.e. users[newUser.id] = newUser happens as a transaction)

[Nezteb]

I’m looking at that now. Thank you for the suggestions! 🙂

[s4nchez]

[...] to prove it out for some architects.

Feel free to point them to this channel if they have any particular concerns they want to address as well 😉

[Nezteb]

I’ll be giving a talk at work about it as soon as I’m done with this service. 😄

[s4nchez]

Cool! Hope it goes well 🙂

[dave]

@Nezteb not sure if you've seen it, but check out the KotlinConf talk on http4k. It's got a bunch of stuff that might be useful as ideas for your talk - the second half especially concerns more systems level stuff like testing improvements: https://bit.ly/serverasafunction