FTP samples

Example: Copy all files from an FTP server to local files

• list FTP server contents (1),
• just bother about file entries (2),
• for each file prepare for awaiting Future results ignoring the stream order (3),
• run a new stream copying the file contents to a local file (4),
• combine the filename and the copying result (5),
• collect all filenames with results into a sequence (6)

Scala

val ftpSettings = FtpSettings(InetAddress.getByName("localhost"), port)

  Ftp
    .ls("/", ftpSettings)                                    // (1)
    .filter(ftpFile => ftpFile.isFile)                       // (2)
    .mapAsyncUnordered(parallelism = 5) { ftpFile =>         // (3)
      val localPath = targetDir.resolve("." + ftpFile.path)
      val dir = Files.createDirectories(localPath.getParent)
      val fetchFile: Future[IOResult] = Ftp
        .fromPath(ftpFile.path, ftpSettings)                
        .runWith(FileIO.toPath(localPath))                   // (4)
      fetchFile.map { ioResult =>                            // (5)
        (ftpFile.path, ioResult)
      }
    }
    .runWith(Sink.seq)                                       // (6)

Scala Imports

import java.net.InetAddress
import java.nio.file.{Files, Paths}

import akka.actor.ActorSystem
import akka.stream.alpakka.ftp.FtpSettings
import akka.stream.alpakka.ftp.scaladsl.Ftp
import akka.stream.scaladsl.{FileIO, Sink}
import akka.stream.{ActorMaterializer, IOResult}
import org.apache.mina.util.AvailablePortFinder

import scala.collection.immutable
import scala.concurrent.Future
import scala.util.{Failure, Success}
import scalasthlm.alpakka.playground.FtpServerEmbedded
import scalasthlm.alpakka.playground.filesystem.FileSystemMock

Running the example code

This example is contained in a stand-alone runnable main, it can be run from sbt like this:

Scala

sbt
> ftpSamples/run