Circe кодеры и декодеры с Http4s

Question

Я пытаюсь использовать http4s, circe и http4s-circe.

Ниже я пытаюсь использовать функцию автоматического вывода Circe.

import org.http4s.client.blaze.SimpleHttp1Client
import org.http4s.Status.ResponseClass.Successful
import io.circe.syntax._
import org.http4s._
import org.http4s.headers._
import org.http4s.circe._
import scalaz.concurrent.Task
import io.circe._

final case class Login(username: String, password: String)
final case class Token(token: String)

object JsonHelpers {
   import io.circe.generic.auto._
   implicit val loginEntityEncoder : EntityEncoder[Login] = jsonEncoderOf[Login]
   implicit val loginEntityDecoder : EntityDecoder[Login] = jsonOf[Login]
   implicit val tokenEntityEncoder: EntityEncoder[Token] = jsonEncoderOf[Token]
   implicit val tokenEntityDecoder : EntityDecoder[Token] = jsonOf[Token]
}

object Http4sTest2 extends App {
   import JsonHelpers._
   val url = "http://"
   val uri = Uri.fromString(url).valueOr(throw _)
   val list = List[Header](`Content-Type`(MediaType.`application/json`), `Accept`(MediaType.`application/json`))
   val request = Request(uri = uri, method = Method.POST)
      .withBody(Login("foo", "bar").asJson)
      .map{r => r.replaceAllHeaders(list :_*)}.run
   val client = SimpleHttp1Client()
   val result = client.fetch[Option[Token]](request){
      case Successful(response) => response.as[Token].map(Some(_))
      case _ => Task(Option.empty[Token])
   }.run
   println(result)
}

Я получаю несколько экземпляров этих двух ошибок компилятора

Error:scalac: missing or invalid dependency detected while loading class file 'GenericInstances.class'.
Could not access type Secondary in object io.circe.Encoder,
because it (or its dependencies) are missing. Check your build definition for
missing or conflicting dependencies. (Re-run with `-Ylog-classpath` to see the problematic classpath.)
A full rebuild may help if 'GenericInstances.class' was compiled against an incompatible version of io.circe.Encoder.


Error:(25, 74) could not find implicit value for parameter encoder: io.circe.Encoder[Login]
   implicit val loginEntityEncoder : EntityEncoder[Login] = jsonEncoderOf[Login]

Answer 1

Я смог решить это. Я сделал поиск в Google по sbt circe зависимости, и я скопировал и вставил первый результат поиска. это было около 0,1, и поэтому у меня ничего не получалось.

Я изменил свои зависимости на

libraryDependencies ++= Seq(
  "org.http4s" %% "http4s-core" % http4sVersion,
  "org.http4s" %% "http4s-dsl" % http4sVersion,
  "org.http4s" %% "http4s-blaze-client" % http4sVersion,
  "org.http4s" %% "http4s-circe" % http4sVersion,
  "io.circe" %% "circe-core" % "0.7.0",
  "io.circe" %% "circe-generic" % "0.7.0"
)

и теперь автоматический вывод работает нормально, и я могу скомпилировать код ниже

import org.http4s.client.blaze.SimpleHttp1Client
import org.http4s._
import org.http4s.headers._
import org.http4s.circe._

import scalaz.concurrent.Task
import io.circe.syntax._
import io.circe.generic.auto._
import org.http4s.Status.ResponseClass.Successful

case class Login(username: String, password: String)
case class Token(token: String)

object JsonHelpers {
   implicit val loginEntityEncoder : EntityEncoder[Login] = jsonEncoderOf[Login]
   implicit val loginEntityDecoder : EntityDecoder[Login] = jsonOf[Login]
   implicit val tokenEntityEncoder: EntityEncoder[Token] = jsonEncoderOf[Token]
   implicit val tokenEntityDecoder : EntityDecoder[Token] = jsonOf[Token]
}

object Http4sTest2 extends App {
   import JsonHelpers._
   val url = "http://"
   val uri = Uri.fromString(url).valueOr(throw _)
   val list = List[Header](`Content-Type`(MediaType.`application/json`), `Accept`(MediaType.`application/json`))
   val request = Request(uri = uri, method = Method.POST)
      .withBody(Login("foo", "bar").asJson)
      .map{r => r.replaceAllHeaders(list :_*)}.run
   val client = SimpleHttp1Client()
   val result = client.fetch[Option[Token]](request){
      case Successful(response) => response.as[Token].map(Some(_))
      case _ => Task(Option.empty[Token])
   }.run
   println(result)
}