Hi guys! I'm currently working on a REST application and try to do that with spring boot, webflux and the functional way with kotlin. With Annotations one could write unit tests by mocking the repository and call the methods of the controller. As the controller returns a Mono of the desired object, it was easily compared and asserted. In the functional way, my handler returns a Mono<ServerResponse>. When I debug it, the desired object is in that ServerResponse, but how to I get it's body? The interface doesn't offer a method for that?! Any help is appreciated! 🙂

This message was deleted.

Hi everyone, i have a problem, i am using code from sources but Ktor returns me not json of data class but just "null" any suggestions ? THX) http://prntscr.com/mobkfz

Do you think #spring can be overtaken by #micronaut? Which one you think is better to work with Kotlin?

Anyone familiar with using the Kotlin Jackson module to parse out a JSON object with nested objects? For the nested objects it seems to only work in cases where the JSON matches exactly (@JsonIgnoreProperties and configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false) do not help, though it works with the top level object). The failure is MismatchedInputException: Cannot construct instance, which I guess makes sense due to data class constructors, but is there some way to make this more flexible? Only parse the fields I need, and not break if the API returns a subset of the fields, or a new field? I'm a Kotlin newbie so just trying to figure this out as I go and any help would be appreciated.

Want to advertise a light-weight server microframework for HTTP services we've been using in production for over a year: Jooby. 1.x has been around for many years and to my mind has a great balance between noninvasiveness (you can easily move off jooby as a framework should you decide to do so), productivity and lightness, but still with great basic feature set. It also has a nice Kotlin DSL for HTTP routes. Tastefully built in my opinion, and you go for a more annotation/injection free style of programming for microservices where application logic code can be given a greater focus because the rest "never gets in the way". Good set of plugins for common use cases. Now 2.x is under development, and a notable feature is Kotlin coroutine support 1.x: https://jooby.org/ (We've been using it for over a year in production) 2.x: https://jooby.io/ (Now with Kotlin coroutines)

Hi every one, may be somebody can help me? https://github.com/Kotlin/kotlinx.coroutines/issues/1026 here is my issue. I think trouble that I’m using 1.3.21 kotlin and something wrong with corrutines

I'm struggling to understand how I can make my ktor server communicate with another server. Maybe because that's a new concept to me since I'm an android developer but as far as I was able to understand I would need to have a reverse proxy component. What I'm trying to do is to have periodic data fetching of another server from ktor so when my client need I will have a lot of data available that was fetched in advance. Like a workmanager on android Could anyone give me a direction and tell me where I should be looking at?

Hi Everyone, I'm fairly new to the backend and I'm looking for an easy way to build a json API. Is there a framework that would allow me to describe my API using some kind of description language and generate some code for me ? (I'm thinking at least serialization/deserialization, parameter checking and documentation generation, maybe also access rules). All the things I have seen so far are still pretty low level and require me to do the error prone json serialization/deserialization, etc...

Someone have a repository of Ktor with Database¿?

Hi all, just started learning Kotlin! I'm a backend developer who is looking to use Kotlin in the backend, specifically for building apis. Out of curiosity, what companies use Kotlin on the backend? Is there a list out there? Most lists I see are for Android dev (which make sense).

If i have a simple rest api on a server - whats the best way to test how many requests per seconds it can do? I am trying to load test it via bench/vegeta/jmeter etc but my client machine runs out of resources i think before i reach the peak

Is there a email library, preferably lightweight, that anybody can recommend to use with ktor?

define “email library”

Hi everyone I'm working with Kafka via Kotlin and we want to transform its

Future

implementation (https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/clients/producer/internals/FutureRecordMetadata.java) as

Deferred

. Could this be a solution?

fun <T> Future<T>.asDeferred(dispatcher: CoroutineDispatcher = Dispatchers.Default): Deferred<T> {
    return GlobalScope.async(dispatcher) {
        get()
    }
}

This message was deleted.

Hey guys! I'm developing a webapp and its working in local on many computers, but when i deploy on remote, the request are pending and not change it. The remote server is TomCat and it's behind a reverse proxy. Anyone know what could be the problem?

Hey guys! I want to develop a system where is possible to “translate” a JSON in another via a web interface. The point of this is give users ability to create those parsers without the programming language. Today I already have this written in NodeJS and using Handlebars (HTML template engine for building JSON sucks 🤮). I’m rewriting some microservices in Kotlin (with #spring) and I’d like your opinion about this system be written in Kotlin? Any suggestion how could I do this?

is there anyone who's familiar with security stuff (dtls handshake, in particular) ideally with bouncycastle but any JCA knowledge would be helpful? i'm trying to navigate all these classes and getting lost amidst everything and could really use some guidance. i get this isn't exactly kotlin-specific but i'm getting desperate.

Hey devs, so I got a problem with creating a fat jar in my project since we I converted the Gradle config from GroovyDSL to KotlinDSL. We used to use the shadowJar plugin, but according to what I googled so far, there should even be a solution without it. So I converted (with the help of Stackoverflow) the Groovy solution (of how to configure the jar-plugin). But

gradle clean build

still doesn't create a fat jar (but at least the main-class is set). Here is the Stackoverflow ticket: https://stackoverflow.com/questions/55575264/creating-a-fat-jar-in-gradle-with-kotlindsl

Does anyone use a Kotlin server lib/framework that supports auto-generation of Swagger YAML files? For example, most JAX-RS libraries support it via `swagger-core`: https://swagger.io/tools/open-source/open-source-integrations/

Kotlin coroutines, are they better than threads when developing server side ? are they a better than Java thread pool ?

hey all, How do you name your DTOs? For example I have a

entity

called

Alert

and for CRUD operations I have a DTO to create, so I’m naming

AlertCreationDTO

but to update I can’t use

AlertCreationDTO

because some fields can’t be updated. So how you organize/name those DTOs?

With regard to Swagger: https://github.com/swagger-api/swagger-core/wiki/Swagger-2.X---Getting-started#what-is-it-about

swagger-core

has a

swagger-models

module that includes all the various bits of a Swagger file as code. Microsoft has https://github.com/Microsoft/OpenAPI.NET for C#, with documentation on how to write a swagger doc with code instead of json/yaml by hand. Is anyone aware of how to do that with

swagger-models

or a library similar to it?

Has anyone used resilience4j with a kotlin project before? Looking to use it as a circuit breaker for all communication with external services. Mostly just want to know if you felt it was a reliable tool and easy to work with or if there was some alternative that you found to be better. https://github.com/resilience4j/resilience4j

Hello. I'm in doubt about on bevahior from all method on Collections:

/**
 * Returns `true` if all elements match the given [predicate].
 * 
 * @sample samples.collections.Collections.Aggregates.all
 */
public inline fun <T> Iterable<T>.all(predicate: (T) -> Boolean): Boolean {
    if (this is Collection && isEmpty()) return true
    for (element in this) if (!predicate(element)) return false
    return true
}

Does this condition:

if (this is Collection && isEmpty()) return true

makes sense? Should return true for applying a predicate to an empty collection? Example:

val s = emptyList<String>()
if (s.all { it.isNotEmpty() }) {
    // should  the code  enter here?
}

Is there a way to get Jetty to be far less verbose with its logging?

Good morning! I’m looking into kotlin as a server side language (api’s & workers). What frameworks are recommended? We’re not a fan of spring’s approach on java with loads of annotations and magic. Prefer the style of akka-http or playframework on scala if anyone is familiar with them.

Another question thats probably impossible to answer. Number of developers. Seems like kotlin has had tremendous success in recent years but i’m guessing most of it comes from android developers moving from java? What about on the server side, is there any data? What companies has moved to use kotlin as their main weapon of choice on the server?