# How to send HTTP requests in scala?

Add the dependency on okhttp client library:

libraryDependencies in ThisBuild += "com.squareup.okhttp3" % "okhttp" % "3.9.1"

Steps to add a 3rd party dependency here.

Define a WebClient utility class with get & post apis:

import java.util.concurrent.TimeUnit
import okhttp3._
import scala.collection.mutable
import scala.collection.JavaConverters._

class WebClient(urlFirstPart:String) {

  private val client = new OkHttpClient().newBuilder()
    .connectTimeout(10, TimeUnit.SECONDS)
    .readTimeout(5, TimeUnit.SECONDS)
    .writeTimeout(5, TimeUnit.SECONDS)
    .cookieJar(new SimpleOkHttpCookieJar)
    .build()

  def post(urlLastPart: String, json: String):(Int, String) = {
    val url = urlFirstPart +  urlLastPart
    val JSON = MediaType.parse("application/json; charset=utf-8")
    val headers = Headers.of("Accept", "application/json")
    val body = RequestBody.create(JSON, json)
    val request = new Request.Builder().url(url).headers(headers).post(body).build
    val response = client.newCall(request).execute
    val code = response.code()
    val responseString = response.body().string()
    response.close()
    code -> responseString
  }

  def get(urlLastPart: String):(Int, String) = {
    val url = urlFirstPart +  urlLastPart
    val headers = Headers.of("Accept", "application/json")
    val request = new Request.Builder().url(url).headers(headers).get().build
    val response = client.newCall(request).execute
    val code = response.code()
    val responseString = response.body().string()
    response.close()
    code -> responseString
  }
}

class SimpleOkHttpCookieJar extends CookieJar {

  private val storage = mutable.Map.empty[String, Cookie]

  override def saveFromResponse(url: HttpUrl, cookies: java.util.List[Cookie]): Unit = {
    val cookieList = cookies.asScala
    storage ++= cookieList.map(c =>  c.name -> c)
  }

  override def loadForRequest(url: HttpUrl): java.util.List[Cookie] = {
    storage --= storage.filter(_._2.expiresAt() < System.currentTimeMillis()).keySet
    storage.filter(_._2.matches(url)).values.toList.asJava
  }
}

Usage sample:

lazy val at: String = "https://httpbin.org/"
val client = new WebClient(at)
//GET calls
val (code, body) = client.get("get")
if (code == 200) {
  //logic to parse the response body can go here..
  //maybe converting the String to JSON helps: body.parseToJsObject
  Success(())
} else Failure(new RuntimeException(s"$code: $body"))

//POST calls
val userName = "seetha"
val password = "Welcome"
val json =
	s"""{
         | "userName" : "$userName",
         | "password" : "$password"
         |}""".stripMargin

val (responseCode, respnseBody) = client.post("post", json)
if (responseCode == 200) Success(())
else Failure(new RuntimeException(s"$responseCode: $respnseBody"))

REFERENCES

OKHttp