ktor http rest client usage sample in kotlin

basicKtor.kt

import io.ktor.client.*
import io.ktor.client.engine.cio.*
import io.ktor.client.features.*
import io.ktor.client.features.auth.*
import io.ktor.client.features.auth.providers.*
import io.ktor.client.features.json.*
import io.ktor.client.features.logging.*
import io.ktor.client.request.*
import io.ktor.http.*
import io.ktor.http.ContentType.Application.Json
import kotlinx.coroutines.runBlocking

val httpClient = HttpClient(CIO) {
  install(Logging) { logger = Logger.DEFAULT; level = LogLevel.INFO }
  install(JsonFeature) { serializer = JacksonSerializer { ObjectMapper() } }
  install(Auth) { basic { credentials { BasicAuthCredentials(username = user, password = pwd) } } }
  defaultRequest {
    header("Authorization", "Basic YWRtaW46YWRtaW4=")
    header("dataType", "json")
  }
}

fun post(content: ContentBean) {
  runBlocking {
    val response = httpClient.post<String>("$url/rest/api/content")
    { contentType(Json); body = content }
    println("response is: $response")
  }
}

// implementation "io.ktor:ktor-client-auth:$ktor_version"
// implementation "io.ktor:ktor-client-cio:$ktor_version"
// implementation "io.ktor:ktor-client-core:$ktor_version"
// implementation "io.ktor:ktor-client-jackson:$ktor_version"
// implementation "io.ktor:ktor-client-logging:$ktor_version"

mockKtor.kt

package demo

import io.ktor.client.*
import io.ktor.client.engine.mock.*
import io.ktor.client.request.*
import io.ktor.http.*
import io.ktor.http.HttpStatusCode.Companion.OK
import kotlinx.coroutines.runBlocking
import mu.KotlinLogging

val logger = KotlinLogging.logger {}

private val responseHeaders = headersOf("Content-Type" to listOf(ContentType.Application.Json.toString()))

val mockClient: HttpClient = HttpClient(MockEngine) {
  engine {
    addHandler { request ->
      when (request.url.encodedPath) {
        "books" -> respond("""{"book1": "Zarathoustra"}""", OK, responseHeaders)
        "comments" -> respond("""{"comment1": "It's great"}""", OK, responseHeaders)
        else -> error("Unhandled ${request.url.encodedPath}")
      }
    }
  }
}

fun main() {
  runBlocking {
    val response1 = mockClient.get<String> { url("/books") }
    logger.info { response1 }
    val response2 = mockClient.get<String> { url("/comments") }
    logger.info { response2 }
  }
}

//implementation "io.ktor:ktor-client-core:$ktor_version"
//implementation "io.ktor:ktor-client-auth:$ktor_version"
//implementation "io.ktor:ktor-client-cio:$ktor_version"
//testImplementation "io.ktor:ktor-client-mock:$ktor_version"