(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, Solaris 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());
  }
}