Hi all, Ktor looks awesome and we’re planning to try it out with an API endpoint. We have an existin...

# ktor

[Alexander Suraphel]

Hi all, Ktor looks awesome and we’re planning to try it out with an API endpoint. We have an existing spring app which has a service class with methods that we want to call from Ktor. How should be go about it? RPC? If so what tools do you recommend?

[Holger Steinhauer [Mod]]

Depends a bit on how your architecture looks like.

[Alexander Suraphel]

It’s based on spring

[Holger Steinhauer [Mod]]

The “cleanest” cut would be interfacing via REST or messaging. Then again, the use case might demand something else

[Holger Steinhauer [Mod]]

Yeah, sure. But are we talking services or monolith? Is the application that uses Spring running in a single instance or clustered? What will the “class” do?

[Alexander Suraphel]

Single instance

[Alexander Suraphel]

i just does some operation and return a result

[Holger Steinhauer [Mod]]

You shouldn’t look at it as a “class” btw. If it provides a useful functionallity, make it available as a service

[Alexander Suraphel]

It’s implemented as service class. I’m just wondering the best way to expose it to an app hosted on the same server

[Holger Steinhauer [Mod]]

Ah, sorry. Spring’s @Service classes have nothing to do with a service that is available from the outside world. It is the “service layer”, where the business logic should be implemented

[Holger Steinhauer [Mod]]

You could create a @Controller making it available as a REST service. This brings up the question how to authenticate and authorize.

[Holger Steinhauer [Mod]]

Then, if you have access to the class itself, you could refactor the actual logic into a little library which your Spring and your Ktor app can then use

[Holger Steinhauer [Mod]]

As I said, it highly depends on what you are actually trying to implement

[Holger Steinhauer [Mod]]

“Making it available somehow when it runs on the same server” sounds a bit hacky to me

[Holger Steinhauer [Mod]]

Also, in order to make things like this possible you need to make sure the apps run on the same JVM instance.

[Alexander Suraphel]

I thought RPC was the standard way of doing such things but Controller seems doable too