Java

Send an FTP NOOP (Keep-Alive)

Demonstrates the Chilkat Ftp2.Noop method, which sends the FTP NOOP command. It takes no arguments and succeeds only when the server returns a positive reply.

Background: NOOP asks the server to do nothing and simply reply, which makes it the standard keep-alive: sending one periodically resets the server's idle timer so a long-running job does not lose its control connection between transfers. Because it exercises a real request/reply round trip, a successful NOOP is also firmer evidence the connection is alive than CheckConnection.

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Java

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    boolean success = false;

    //  Demonstrates the Ftp2.Noop method, which sends the FTP NOOP command.  It takes no arguments.
    //  The server must return a positive reply for the method to succeed.

    CkFtp2 ftp = new CkFtp2();

    ftp.put_Hostname("ftp.example.com");
    ftp.put_Username("myFtpLogin");

    //  Normally you would not hard-code the password in source.  You should instead obtain it
    //  from an interactive prompt, environment variable, or a secrets vault.
    ftp.put_Password("myPassword");

    //  Connect and log in (Connect performs both).
    success = ftp.Connect();
    if (success == false) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    //  NOOP does nothing on the server, but a successful reply confirms the control connection is
    //  still responsive -- useful as a keep-alive during an otherwise idle session.
    success = ftp.Noop();
    if (success == false) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    System.out.println("NOOP acknowledged by the server.");

    success = ftp.Disconnect();
    if (success == false) {
        System.out.println(ftp.lastErrorText());
        return;
        }
  }
}