Maven dependency

Add the OfficeFloor Kotlin support alongside the Spring Boot starter:

		<dependency>
			<groupId>net.officefloor.kotlin</groupId>
			<artifactId>officekotlin</artifactId>
		</dependency>

Application class

@SpringBootApplication
open class Application

fun main(args: Array<String>) {
    runApplication<Application>(*args)
}

Kotlin service function

The Kotlin top-level function that handles the request uses @RequestBody for the request body and ObjectResponse to send the response:

package net.officefloor.tutorial.kotlinhttpserver

import net.officefloor.web.ObjectResponse
import org.springframework.web.bind.annotation.RequestBody

fun service(@RequestBody request: KotlinRequest, response: ObjectResponse<KotlinResponse>) {
	response.send(KotlinResponse("Hello ${request.name} from Kotlin"))
}

REST endpoint

The YAML file routes POST '/' to the Kotlin function via the Kotlin procedure source. The compiled class name for a Kotlin file of top-level functions is <filename>Kt:

Kotlin:
  resource: net.officefloor.tutorial.kotlinhttpserver.KotlinLogicKt
  procedure: Kotlin
  method: service

Kotlin data classes

Kotlin data classes work directly as JSON request and response objects. Jackson's Kotlin module (included via officekotlin) handles serialisation automatically:

data class KotlinRequest(val name: String)

data class KotlinResponse(val message: String)

Testing

@SpringBootTest
@AutoConfigureMockMvc
class KotlinHttpServerTest {

    @Autowired
    lateinit var mvc: MockMvc

    @Autowired
    lateinit var mapper: ObjectMapper

    @Test
    fun service() {
        mvc.perform(post("/")
                .accept(MediaType.APPLICATION_JSON)
                .contentType(MediaType.APPLICATION_JSON)
                .content(mapper.writeValueAsString(KotlinRequest("Daniel"))))
                .andExpect(status().isOk)
                .andExpect(content().json(mapper.writeValueAsString(KotlinResponse("Hello Daniel from Kotlin"))))
    }
}