Scala の HttpClient の使い方 (Get)

次の Java プログラムを scala で書いてみました。
Java の HttpClient の使い方 (Get)

Http_get.scala

// -------------------------------------------------------------------
//  Http_get.scala
//
//                  Jun/12/2021
//
// -------------------------------------------------------------------
import java.io.IOException
import java.io.UnsupportedEncodingException
import java.nio.charset.Charset
import java.nio.charset.StandardCharsets
import org.apache.http.HttpStatus
import org.apache.http.client.ClientProtocolException
import org.apache.http.client.methods.CloseableHttpResponse
import org.apache.http.client.methods.HttpGet
import org.apache.http.impl.client.CloseableHttpClient
import org.apache.http.impl.client.HttpClients
import org.apache.http.util.EntityUtils


// -------------------------------------------------------------------
object Http_client {

def runSample() = {
    System.err.println ("*** runSample *** start ***")

    var charset = StandardCharsets.UTF_8

    var httpclient = HttpClients.createDefault()

    var request = new HttpGet("https://httpbin.org/get")

    println ("requestの実行　「" + request.getRequestLine() + "」")

    var response:CloseableHttpResponse = null


    try {
        response = httpclient.execute(request)

        var status = response.getStatusLine().getStatusCode()
        println("HTTPステータス:" + status)

        if (status == HttpStatus.SC_OK){                
            var responseData = 
                    EntityUtils.toString(response.getEntity(),charset)              
            println(responseData)
            }
        } catch {
            case e: ClientProtocolException => e.printStackTrace()
            case e: UnsupportedEncodingException => e.printStackTrace()
            case e: IOException => e.printStackTrace()

        } finally {

            try {
                if (response != null) {
                    response.close()
                }
                if (httpclient != null) {
                    httpclient.close()
                }
            } catch {
                case e: IOException => e.printStackTrace()
            }

        }

        System.err.println ("*** runSample *** end ***")
    }
}


// -------------------------------------------------------------------
object Http_get {

def main(args: Array[String])
{
    System.err.println ("*** 開始 ***")

    Http_client.runSample()

    System.err.println ("*** 終了 ***")
}
}

// -------------------------------------------------------------------

Makefile

LIB=/usr/share/java
HTTPCLIENT_JAR=.:$(LIB)/httpclient-4.5.13.jar:$(LIB)/httpcore-4.4.14.jar
Http_get.class: Http_get.scala
    scalac -cp $(HTTPCLIENT_JAR) Http_get.scala
clean:
    rm -f *.class

実行コマンド

LIB=/usr/share/java
HTTPCLIENT_JAR=$LIB/httpclient-4.5.13.jar:$LIB/httpcore-4.4.14.jar:$LIB/commons-logging-1.2.jar
export CLASSPATH=.:$HTTPCLIENT_JAR
#
scala Http_get