As previously stated, OkHttp's APIs were built with ease of use in mind. As a consequence, sending requests via OkHttp is quick and hassle-free. The following is a post(String, String) method that takes a URL and JSON request body as its arguments and sends a POST request to the specified URL with the JSON body:

fun post(url: String, json: String): String {
  val mediaType: MediaType = MediaType.parse("application/json;
                                              charset=utf-8")
  val client:OkHttpClient = OkHttpClient()
  val body: RequestBody = RequestBody.create(mediaType, json)

  val request: Request = Request.Builder()
                                .url(url)
                                .post(body)
                                .build()

  val response: Response = client.newCall(request).execute()
  return response.body().string()
}

Using the preceding function is straightforward. Invoke it with appropriate values, as you would any other function:

val fullName: String = "John Wayne"
val response = post("http://example.com", "{ "full_name": $fullName")

println(response)

Easy, right? Glad you agree. Communicating with a remote server is fun with OkHttp but using Retrofit to do this is even more fun. We are almost ready to work with Retrofit, but, before we explore Retrofit, it's a good idea to properly model the data we will be sending in our HTTP requests.