Vert.x Web + Kotlin Coroutines

build.gradle.kts

import org.jetbrains.kotlin.gradle.tasks.KotlinCompile

plugins {
    kotlin("jvm") version "1.7.10"
}

group = "org.example"
version = "1.0-SNAPSHOT"

repositories {
    mavenCentral()
}

dependencies {
    implementation("io.vertx:vertx-web:4.3.3")
    implementation("io.vertx:vertx-lang-kotlin-coroutines:4.3.3")
    implementation("io.vertx:vertx-lang-kotlin:4.3.3")
    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4")
}


tasks.withType<KotlinCompile> {
    kotlinOptions.jvmTarget = "1.8"
}

Main.kt

import io.vertx.core.Vertx
import io.vertx.ext.web.Route
import io.vertx.ext.web.Router
import io.vertx.ext.web.RoutingContext
import io.vertx.kotlin.coroutines.CoroutineVerticle
import io.vertx.kotlin.coroutines.await

import kotlin.coroutines.CoroutineContext
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch


suspend fun coroutineDemo(): String {
    delay(3000)
    return "Hello World"
}

public fun Route.coroutineHandler(
    coroutineContext: CoroutineContext,
    userHandler: suspend (RoutingContext) -> Unit
) = handler { routingContext ->
    CoroutineScope(coroutineContext).launch {
        try {
            userHandler(routingContext)
        } catch (exception: Exception) {
            routingContext.fail(exception)
        }
    }
}


class MainVerticle() : CoroutineVerticle() {
    override suspend fun start() {
        val router = Router.router(vertx);

        router.route("/hello").coroutineHandler(coroutineContext) { routingContext ->
            val payload = coroutineDemo()
            routingContext.response().send(payload)
        }

        vertx.createHttpServer().requestHandler(router).listen(8080).await()
    }
}

fun main() {
    val vertx = Vertx.vertx()
    vertx.deployVerticle(MainVerticle())
}