@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_main);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        //requestPermissions(new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
        //requestPermissions(new String[]{Manifest.permission.INTERNET}, 1);
        ActivityCompat.requestPermissions(MainActivity.this,new String[]
                {Manifest.permission.READ_EXTERNAL_STORAGE}, 1);
        ActivityCompat.requestPermissions(MainActivity.this,new String[]
                {Manifest.permission.INTERNET}, 1);
    }
}

public void Upload()
{

    TextView Result= (TextView) findViewById(R.id.Conn);
    String URL= ((EditText) findViewById(R.id.URL)).getText().toString();
    String Username= ((EditText) findViewById(R.id.Username)).getText().toString();
    String Password= ((EditText) findViewById(R.id.Password)).getText().toString();
    FTPClient FTPClient=new FTPClient();
    FTPClient.enterLocalPassiveMode();
    try {
        InetAddress indirizzo = InetAddress.getByName(URL);
        FTPClient.connect(indirizzo);
        Result.setText(FTPClient.getReplyString());
        //aperta la connessione al server procedo al login

        boolean login=FTPClient.login(Username,Password);
        if(login==true)
            Result.append(" ..login effettuato");

        else Result.append("...login fallito");

        //apro il file contenuto nel path /sdcard come stream
        /*client.setFileType(FTP.BINARY_FILE_TYPE); // imposto il tipo di dati, da modificare a seconda dell'utilità
        File sdcardDir = Environment.getExternalStorageDirectory(); //dato che il mio file era sulla sd prendo il riferimento alla memoria       esterna
        File file = new File(sdcardDir,"fotografia.jpeg"); //prendo il riferimento al file salvato sulla sd
        FileInputStream fis = new FileInputStream(file);//creo uno stream in input a partire dal mio file

        //risposta.append("...path file: " + file.getPath()); //questa istruzione la usavo per test, la lascio casomai dovesse servire, stampa semplicemente il path del file che voglio uploadare

        boolean upload_ok=client.storeFile("fotografia.jpeg", fis);
        fis.close();//procedo alla chiusura dello stream, infatti storeFile non chiude fis
        if(upload_ok==true)risposta.append("  ..... upload ok");
        else risposta.append("....upload fallito, errore: " + upload_ok);*/

    } catch (SocketException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case 1: {

            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission granted
                Toast.makeText(MainActivity.this, "Permission denied", Toast.LENGTH_SHORT).show();}

            else {

                // permission denied
                Toast.makeText(MainActivity.this, "Permission denied", Toast.LENGTH_SHORT).show();
            }
            return;
        }
    }
}