Scala Client/Server

//SERVER
import java.net._
import java.io._
import scala.io._
import scala.util.control._
import java.lang.String
import collection.mutable.HashMap

object HelloServerWorld {
  class ScalaServer(val _conn: Socket, _root:String) extends Runnable {
    val CONN = _conn
    var root:String = _root
    val in = new DataInputStream(CONN.getInputStream())
    val out = new DataOutputStream(CONN.getOutputStream())

    def getListOfFiles(dir: String):List[File] = {
      val d = new File(dir)
      if (d.exists && d.isDirectory) {
        d.listFiles.filter(_.isFile).toList
      } else {
      List[File]()
      }
    }

    def Pwd() : Unit = {
        var dir:String = '\t'+System.getProperty("user.dir")
        out.writeUTF("\n"+dir)
        out.flush()
    }

    def ls() : Unit = {
        val Currdir = System.getProperty("user.dir")
        val files = getListOfFiles(Currdir)
        var dirs :String = "\n"
        for ( i <- 0 to (files.length - 1)) {
          dirs += '\t'+files(i).getName()+'\n'
        }
        out.writeUTF(dirs)
        out.flush()
    }

    def cd() : Unit = {
      val outer = new Breaks
      outer.breakable {
        while(true)
        {
          out.writeUTF("Insert absolute path of the directory that you want to navigate to: ")
            out.flush()
            var dir :String = in.readUTF()
            var CurrentDir:String = System.getProperty("user.dir")
            var dirToBE:String = root.replace('\\','/')
            println(dir)
            System.setProperty("user.dir", dirToBE+"/"+dir)
            println(System.getProperty("user.dir"))
            out.writeUTF("Current directory is: "+System.getProperty("user.dir"))
            out.flush()
            outer.break
        }
      }
    }

    def saveFile() : Unit = {
    out.writeUTF("Input file path")
    out.flush()
    val archivoName = in.readUTF()
    val tam = in.readUTF()
    if(archivoName != "File does not exists"){
        val fos = new FileOutputStream(archivoName)
        var bytes = new Array[Byte](1024)
        var bytesLeidos:Int = 0
        var tama:Int = Integer.parseInt(tam)
        println(tama)
        while(tama > 0) {
            if(tama <= 1024){
                bytesLeidos = in.read(bytes, 0, tama)
            } else{
                bytesLeidos = in.read(bytes, 0, 1024)
            }
            tama -= bytesLeidos
            fos.write(bytes, 0, bytesLeidos)
        }
        fos.close()
        out.writeUTF("Received successfully")
        out.flush()
    }else {
        out.writeUTF("File does not exists")
        out.flush()
    }
}

    def mkdir() : Unit = {
    out.writeUTF("Name of new directory: ")
    out.flush()
    val _dirName = in.readUTF()
    val mkDir = new File(System.getProperty("user.dir") + "/" + _dirName)
    val successful = mkDir.mkdir();
    if(successful) {
        out.writeUTF("Directory successfully created")
    }else {
        out.writeUTF("Unable to create directory")
    }
    out.flush()
  }

def rm() : Unit = {
    out.writeUTF("Name of file/directory to delete: ")
    out.flush()
    val delPath = in.readUTF()
    val rm = new File(System.getProperty("user.dir") + "/" + delPath)
    if(rm.exists) {
        rm.delete()
        out.writeUTF("Deleted successfully")
    }else {
        out.writeUTF("Unable to delete")
    }
    out.flush()
}

def sendFile() : Unit = {
    out.writeUTF("File to download")
    out.flush()
    val estoQuiero = in.readUTF()
    val archivo = new File(estoQuiero)
    if(archivo.exists){
        out.writeUTF(archivo.length.toString())
        out.flush()
        val fos = out
        val leer = new FileInputStream(estoQuiero);
        var bytes = new Array[Byte](1024);
        var tama:Int = archivo.length.intValue()
        var bytesLeidos:Int = 0
        while(tama > 0) {
            if(tama <= 1024){
                bytesLeidos = leer.read(bytes, 0, tama)
            } else{
                bytesLeidos = leer.read(bytes, 0, 1024)
            }
            tama -= bytesLeidos
            fos.write(bytes, 0, bytesLeidos)
        }
        leer.close();
        out.writeUTF("File sent successfully")
        out.flush()
    }else{
        out.writeUTF("File does not exists")
        out.flush()
    }
}

def userHandler(user: String, password: String) : Boolean = {
    var usuarios = HashMap[String, String]()
    val archivo = new File("users.txt")
    var leido = ""
    if (archivo.exists){
        Source.fromFile("users.txt" ).foreach{case line =>
            leido += line
      }
        var splitUsers: Array[java.lang.String] = leido.split(",").map(_.trim)
        var esUsuario = 0;
        var arrayTam = splitUsers.size
        while(arrayTam > esUsuario){
            usuarios(splitUsers(esUsuario)) = splitUsers(esUsuario+1)
            esUsuario += 2
        }
    }

    if(usuarios contains user){
        if(usuarios(user) == password){
            println("Login success")
            return true
        }else{
            println("Contraseña incorrecta")
            return false
        }
    }else {
      out.writeUTF("User does not exist, do you want to create [Y/N]")
      if(in.readUTF()=="Y"){
        usuarios(user) = password
        println("Usuario creado y login success")
        }
    }

    val writer = new PrintWriter(new File("users.txt" ))
    var tam = usuarios.size
    var iteracion = 0;
    usuarios.foreach{case(key, value) =>
        writer.write(key)
        writer.write(",")
        writer.write(value)
        if(iteracion != (tam-1)){
            writer.write(",")
        }
        iteracion += 1;
    }
    writer.close()
    return false
}

    def logic() : Unit = {
      while(true){
      var login:String = "\n"
      login+="\t"+"--------Login--------"+"\n"
      login+="\t"+"Input you username: "+"\n"
      out.writeUTF(login)
      var userName:String= in.readUTF()
      out.writeUTF("Input you password: ")
      var password:String= in.readUTF()
      System.setProperty("user.dir",root)
      if(userHandler(userName,password)){
      while(true){
        out.writeUTF(" ")
        val received = in.readUTF()
        println("Message Received:" + received)
        if(received == "pwd"){
          Pwd()
        }else if (received == "ls"){
          ls()
        }else if(received == "cd"){
          cd()
        }else if(received == "get"){
          sendFile()
          out.writeUTF("")
        }else if(received == "put"){
          saveFile()
        }else if(received == "rm"){
            rm()
        }else if(received == "mkdir"){
            mkdir()
        }else{
          out.writeUTF('"'+received+'"'+" is not a valid command.")
          out.flush()
        }
      }
      }else{
        out.writeUTF("Acces denied")
        out.flush()
      }
    }
    }
    def run {
      logic()
    }
}

  def main(args: Array[String]){
    val server = new ServerSocket(9999)
    val cont = true
    var root:String = System.getProperty("user.dir")
    while (cont) {
        val s = server.accept()
        println(s.getRemoteSocketAddress())
        new Thread(new ScalaServer(s,root)).start
    }
  }
}


//CLIENT

import java.net._
import java.io._
import scala.io._
import scala.util.control._

  def sendFile() : Unit = {
    val mensaje2 = in.readUTF()
    println("Received: " + mensaje2)
    val text2 =  StdIn.readLine()
    val archivo = new File(text2)
    if(archivo.exists){
        out.writeUTF(archivo.getName())
        out.flush()
        out.writeUTF(archivo.length.toString())
        out.flush()
        val leer = new FileInputStream(text2);
        var bytes = new Array[Byte](1024);
        var tama:Int = archivo.length.intValue()
        var bytesLeidos:Int = 0
        while(tama > 0) {
            if(tama <= 1024){
                bytesLeidos = leer.read(bytes, 0, tama)
            } else{
                bytesLeidos = leer.read(bytes, 0, 1024)
            }
            tama -= bytesLeidos
            out.write(bytes, 0, bytesLeidos)
        }
        leer.close();
    }else{
        out.writeUTF("No existe")
        out.flush()
        out.writeUTF(0+"")
        out.flush()
    }
}

def getFile() : Unit = {
    val mensaje2 = in.readUTF()
    println("Received: " + mensaje2)
    val estoQuiero =  StdIn.readLine()
    out.writeUTF(estoQuiero)
    out.flush()
    val mensaje3 = in.readUTF()
    if(mensaje3 != "File does not exists"){
        println("receiving file")
        //val tam = Integer.parseInt(mensaje3)
        val fos = new FileOutputStream(estoQuiero)
        var bytes = new Array[Byte](1024)
        var bytesLeidos:Int = 0
        var tama:Int = Integer.parseInt(mensaje3)
        while(tama > 0) {
            if(tama <= 1024){
                bytesLeidos = in.read(bytes, 0, tama)
            } else{
                bytesLeidos = in.read(bytes, 0, 1024)
            }
            tama -= bytesLeidos
            fos.write(bytes, 0, bytesLeidos)
        }
        fos.close()
        val mensaje4 = in.readUTF()
        println("Received: " + mensaje4)
    }else{
        println("Received: " + mensaje3)
    }
}


val s = new Socket(InetAddress.getByName("localhost"), 9999)
lazy val in = new DataInputStream(s.getInputStream())
val out = new DataOutputStream(s.getOutputStream())

while (true) {
    println("Message from server: " + in.readUTF())
    println("Text to send: ")
    val text = StdIn.readLine()
    out.writeUTF(text)
    out.flush()
    if(text=="put")
    {
        sendFile()
    }else if(text == "get")
    {
        getFile()
    }
    //s.close()
}