Re: Instanceof design doubt in Java

Hi
I have a problem in a program design. I want to implement an
application that transfer files between two folders. Folders can be in
the same or remote computer and can have differents types (ftp or file
copy, for example). For example, I want to transfer a file from a
shared folder in a remote computer to a remote ftp site. I have made
this design:

public class Site {
  String folder;}

public class RemoteSite extends Site {
  String host;
  int port;

}

public abstract class TransferType {
  public abstract get (Site site, String file); // transfer file from
site to local
  public abstract put (Site site, String file); // transfer file from
local to site}

public class CopyType extends TransferType {
  public void get (Site site, String file) {
    if (site instanceof RemoteSite)
       // do transfer
    else
      // do transfer
  }

  public void put (Site site, String file) {
    if (site instanceof RemoteSite)
       // do transfer
    else
      // do transfer
  }}

public class FtpType extends TransferType {
  String user;
  String password;

  public void get (Site site, String file) { ...instanceof ... }
  public void put (Site site, String file) { ...instanceof ... }

}

public class Transfer
{
  Site origin;
  Site destination;
  TransferType typeOrigin;
  TransferType typeDestination;

  public void transferFile (String file)
  {
    typeOrigin.get (origin, file);
    typeDestination.put (destination, file);
  }

}

Does somebody knoes how avoid "instanceof" in TransferType classes? I
have thought in others designs but I haven't got a good solution.

Thanks
David