java callback 을 scala Future 로 바꾸기

문제

다음과 같이 java Async Http Client 의 callback 을 scala Future 로 변경해 코딩해 보자

    val asyncHttpClient = org.asynchttpclient.Dsl.asyncHttpClient()
    val listenableFuture =
      asyncHttpClient.prepareGet("https://api.agify.io/?name=meelad").execute()

    val listener = new Runnable {
      override def run(): Unit = {
        val body: String =
          listenableFuture.get().getResponseBody(scala.io.Codec.UTF8.charSet)
        println(body)
      }
    }

    listenableFuture.addListener(listener, null)
    Thread.sleep(3000)
    asyncHttpClient.close()

 

코드

    import scala.concurrent.ExecutionContext.Implicits.global
    import scala.concurrent.{Future, Promise}

    val p = Promise[String]
    val asyncHttpClient = org.asynchttpclient.Dsl.asyncHttpClient()
    val listenableFuture =
      asyncHttpClient.prepareGet("https://api.agify.io/?name=meelad").execute()

    listenableFuture.addListener(
      () => {
        val body: String =
          listenableFuture.get().getResponseBody(scala.io.Codec.UTF8.charSet)
        p.success(body)
      },
      null
    )

    val scalaFuture: Future[String] = p.future
    scalaFuture.foreach(println)

    Thread.sleep(3000)
    asyncHttpClient.close()

 

설명

java callback 을 ZIO 로 바꾸는 것도 가능한데, https://wefree.tistory.com/200 를 참고