This might help: https://spring.io/guides/tutorials/spring-boot-kotlin/ see the UserController class

I would strongly advise against that. It does things in a way that goes against the philosophy of Spring, and DI in general. And it makes the code impossible to test. Say you create a mock repository and inject it into a service that you want to unit-test. The save() method of the user will not use the mocked repository. It will try to access a global USER_REPOSITORY variable, which might or might not be initialized depending on which tests have been run before. DI is your friend. It’s used for good reasons.

Can someone point me to an article/anything that could help understand the bare of spring?

I end up writing a lot of

@Bean
fun springClassInstance() = SpringClass().apply {
    setA(a)
    setB(b)
    setC(c)
}

this syntax just makes me cry. it's a shame there can't be more constructor variants or at the very least builders for some of these classes... it would be so much nicer to just be

@Bean fun springClassInstance() = SpringClass(a = a, b = b, c = c)

but you know.... java things. nvm me, complaining to the ether

Is there a way to add methods to Repository interfaces that are not intended as queries? e.g.

interface Repository<E : MyEntity> : JpaRepository<E, String> {
    operator fun contains(id: String) = existsById(id)

    operator fun get(id: String) = findByIdOrNull(id)
}

I'm exploring the possibility of having route controllers talk directly to repos, but a service in the middle to transform dao and dto is probably still too useful to warrant that

I don’t think you can combine an update with an inner join

I intend to make Spring DSL class (like

RouterFunctionDsl

) constructors internal via

internal constructor

since they are intended to be used only via builder functions like

router { }

,

bean { }

or extensions like

mockMvc.get()

. Any objection?

Anybody already tried using

kotlinx.serialization

with SpringBoot? Or it’s not a good idea to explore this?

I tried using

@ConstructorBinding
@ConfigurationProperties("push")
data class PushServicesProperties(val snsClient: SnsClient) {

    data class SnsClient(
        val maxConnections: Int,
        val connectionTimeout: Int,
        val socketTimeout: Int,
        val proxyHost: String,
        val proxyPort: Int
    )
}

But I'm still getting

No default constructor found

for the

PushServiceProperties

class. Has anyone else had that problem? Everything looks normal...

Hi guys! I'm struggling with testing Controllers based on WebFlux. I'm getting an error:

No qualifying bean of type 'kotlin.coroutines.CoroutineContext' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}

My controller looks like:

@Controller
class MobileController {

  @PostMapping("/register")
  suspend fun register() {
    ...
  }
}

and my test:

@WebFluxTest(MobileController::class)
internal class MobileControllerTest {

    @Autowired
    lateinit var client: WebTestClient

    @Test
    fun handleRegister() = kotlinx.coroutines.runBlocking {
        <http://client.post|client.post>()
                .uri("/register")
                .exchange()
                .expectStatus().isOk
    }
}

Does anyone know how to fix it? Thanks in advance 🙂

Hey, I was looking around here, documentation and checked how does openapi-generator does it - and still everywhere the DTOs for Spring are using nullable fields with defaults, is there a better way to make json handle data classes? openapi does it like this

data class Pet (

        @get:NotNull 
        @JsonProperty("name") val name: kotlin.String,

        @get:NotNull 
        @JsonProperty("photoUrls") val photoUrls: kotlin.collections.List<kotlin.String>,

        @JsonProperty("id") val id: kotlin.Long? = null,

        @JsonProperty("category") val category: Category? = null,

        @JsonProperty("tags") val tags: kotlin.collections.List<Tag>? = null,

        @JsonProperty("status") val status: Pet.Status? = null
)

Has anyone come across of this error? Using data class with Spring Data Rest. The

kotlin('plugin.allopen')

was added to the gradle.

@Component
class UserRestConfigurer : RepositoryRestConfigurer {

    override fun configureRepositoryRestConfiguration(config: RepositoryRestConfiguration) {
        config.withEntityLookup()
            .forRepository<User, Long, UserRepository>(UserRepository::class.java)
            .withIdMapping(User::email)
            .withLookup(UserRepository::findByEmail)
    }
}

Hi, I remember watching some video where speaker was talking about changes in Spring 5.Some.Version. There was something about difference between

@Configuration class MyConf(private val someBean: SomeBean) {
    @Bean fun myBean(): MyBean { /* do something with someBean */ }
}

and

@Configuration class MyConf {
    @Bean fun myBean(someBean: SomeBean): MyBean { /* do something with someBean */ }
}

But I don't remember either which video it was or what was the difference. Googling around didn't yield any results yet. Does anyone remember/know what I'm talking about?

How hard is it to write a new provider for spring data? (to support a new database)

Is there an equivalent for @ControllerAdvice when using the new functional API in WebMVC? I'd like to put some generic information (like user, menu etc.) into the model but don't want to always call a function like "baseModel(...)". I'm also open for other ideas 🙂

Hey, so I'm making a call to spring boot from android and it returns code 500, no message or anything and spring doesn't show the error. How do I go about finding out what the issue is?

In 2.2.2 release of Spring Boot, Kotlin was updated to 1.3.60, but coroutines version was not updated to 1.3.2-1.3.60. Is this a mistake or intentional?

So why are not all endpoints non-blocking.. Or are they? I am thinking of co-routines and that one needs to use WebFlux/Netty in order to achieve this. In Python, async is build into the language interpreter, not spawning any new threads. I am talking about aiohttp in this case. In "Normal Java" one would go about and spawn threads a few years ago. but today, in kotlin and spring, why arent all endpoints non-blocking by default,? Or are we heading there - are we just interim these two paradigms.

Hello, with my team we want to make a progressive transition to webflux. But we would like to use the coroutine support of webflux instead of Mono/Flux. I’ve seen in the presentation from Sébastien at KotlinConf that the support for coroutine in WebMVC controllers are not available yet. I’m wondering if it’s a good alternative to begin refactoring the app to have a big

runBlocking { }

inside the WebMVC controller until all of the controller are refactored, and when we are ready, to remove the dependency to webmvc to enable the full reactive stack, remove all the

runBlocking

and convert the controller methods to

suspend

?

with latest spring boot and kotlin I'd like to have something like this:

@Component class MyComponent(...) {
  fun someFun() {
    /* do something non-transactional before the transaction */
    inTransaction(txType = TxType.REQUIRED, readOnly = false) {
      /* do something inside a transaction */
    }
    /* do something non-transactional after the transaction */
  }
}

What would be the best way to implement the

inTransaction

fun?

hey everyone i have a quick question: since the authorization server for oauth2 is deprecated now, what is the preferred method to have oauth2 in spring going forward?

I am using a

data class

for the Entity but, unless I'm missing something, I'm not sure that should matter. Has anybody successfully used a delegate in their entities?

I want to add annotations on my package. I can do so with adding

package-info.java

file near my Kotlin code. It works while I run my app from IDE, but if I package app as a fat jar (

gradle bootJar

), it stops working. The only fix I came across is to place the package-info in

src/java

instead of

src/kotlin

. Is there a way to instruct gradle to include package-info.java to resulting spring boot jar?

Hi All @here, I'm an android dev, I have planned to start back-end now. I know the basics in java servlets. I have planned to start spring frame work. Please help me to start.

How do you handle that they both want to control the app lifecycle

When writing Spring REST services in Kotlin, would controller functions be a typical and safe place to call

runBlocking { }

?

hello, any idea how to verify JSON response from WebTestClient to check if fields are null? e.g.

testClient.get()
    .uri("whatever")
    .accept(APPLICATION_JSON)
    .exchange()
    .expectStatus().isOk
    .expectBody()
    .jsonPath("$.whatever").isEqualTo(null) // NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS

If I enable

jsr305=strict

compiler settings the above fails complaining it expects non-null

Any

got my spring+jfx prototype working

Hi, I’m trying to build a multi-module, aggregation type, spring boot project (like in https://www.baeldung.com/spring-boot-multiple-modules) I got a root pom.xml that specifies 2 modules: 1 app module and 1 library module when I run

mvn clean package

, the library module compiles successfully but the application module does not find the library module with error

Unresolved reference: thelibrarymodule

This sounds like a classic spring boot problem, but no post in internet seem to have proper fix/explanation. This is driving me insane Can someone please help me? any explanation of the root cause or any suggested keyword to google with? Thanks in advance

Hi guys, I am new and starting out with Coroutines and Spring integration. Now that Spring Boot 2.2 are released, is there a comprehensive example where a basic crud app is using coroutines (I guess probably with R2DBC)? I want to learn how and where to spawn coroutines and know when to use the right context. Thanks