FTP examples

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)
import java.net.InetAddress
import java.nio.file.Paths

import akka.stream.IOResult
import akka.stream.alpakka.ftp.FtpSettings
import akka.stream.alpakka.ftp.scaladsl.Ftp
import akka.stream.scaladsl.{FileIO, Sink}
import org.apache.mina.util.AvailablePortFinder
import playground.filesystem.FileSystemMock
import playground.{ActorSystemAvailable, FtpServerEmbedded}

import scala.collection.immutable
import scala.concurrent.Future
import scala.util.{Failure, Success}
  val ftpSettings = FtpSettings(InetAddress.getByName("localhost"), port)

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

Full source

Running the example code

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

> doc-examples/run
The source code for this page can be found here.