(Java) Synchronize Local Directory Tree

Downloads files from the FTP server to a local directory tree. Synchronization modes include:

mode=0: Download all files
mode=1: Download all files that do not exist on the local filesystem.
mode=2: Download newer or non-existant files.
mode=3: Download only newer files. If a file does not already exist on the local filesystem, it is not downloaded from the server..
mode=5: Download only missing files or files with size differences.
mode=6: Same as mode 5, but also download newer files.
mode=99: Do not download files, but instead delete remote files that do not exist locally.

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux Java Libs for Android

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[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkFtp2 ftp = new CkFtp2();

    ftp.put_Hostname("ftp.example.com");
    ftp.put_Username("login");
    ftp.put_Password("password");

    ftp.put_KeepSessionLog(true);

    // Connect and login to the FTP server.
    boolean success = ftp.Connect();
    if (success != true) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    // Set the current remote directory to the root of
    // the tree to be downloaded.
    success = ftp.ChangeRemoteDir("/subDir1");
    if (success != true) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    // Recursively download all non-existant and newer files.
    int mode = 2;
    success = ftp.SyncLocalTree("c:/temp/subDir1",mode);
    if (success != true) {
        System.out.println(ftp.lastErrorText());
        return;
        }

    success = ftp.Disconnect();

    // Display the session log.  
    System.out.println(ftp.sessionLog());
  }
}