Télécharger dossier dans un serveur FTP

bonjour,je voudrai savoir comment télécharger un dossier contient plusieurs fichiers dans un serveur FTP et stocker dans un disque local,
j'ai un code pour lister les fichiers dans le dossier mais pas le stocker dans un disque dur local,
comment faire?
besoin d'aide,
voici le code

import java.io.IOException;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;
public class FTPListRecursiveDemo {
    static void listDirectory(FTPClient ftpClient, String parentDir,
            String currentDir, int level) throws IOException {
        String dirToList = parentDir;
        if (!currentDir.equals("")) {
            dirToList += "/" + currentDir;
        }
        FTPFile[] subFiles = ftpClient.listFiles(dirToList);
        if (subFiles != null && subFiles.length > 0) {
            for (FTPFile aFile : subFiles) {
                String currentFileName = aFile.getName();
                if (currentFileName.equals(".")
                        || currentFileName.equals("..")) {
                    // skip parent directory and directory itself
                    continue;
                }
                for (int i = 0; i < level; i++) {
                    System.out.print("\t");
                }
                if (aFile.isDirectory()) {
                    System.out.println("[" + currentFileName + "]");
                    listDirectory(ftpClient, dirToList, currentFileName, level + 1);
                } else {
                    System.out.println(currentFileName);
                }
            }
        }
    }
    public static void main(String[] args) {
        String server = "10.11.15.137";
        int port = 21;
        String user = "stgzo";
        String pass = "jayzman1";
        FTPClient ftpClient = new FTPClient();
        try {
            ftpClient.connect(server, port);
            int replyCode = ftpClient.getReplyCode();
            if (!FTPReply.isPositiveCompletion(replyCode)) {
                System.out.println("Connect failed");
                return;
            }
            boolean success = ftpClient.login(user, pass);
            if (!success) {
                System.out.println("Could not login to the server");
                return;
            }
            String dirToList = "/var/opt/ericsson/nms_umts_pms_seg/segment1/UETR/SubNetwork=ANRNC02/MeContext=ANRNC02";
            listDirectory(ftpClient, dirToList, "", 0);
        } catch (IOException ex) {
            System.out.println("Oops! Something wrong happened");
            ex.printStackTrace();
        } finally {
            // logs out and disconnects from server
            try {
                if (ftpClient.isConnected()) {
                    ftpClient.logout();
                    ftpClient.disconnect();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
}

Merci
jayzman