Télécharger dossier dans un serveur FTP

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();
            }
        }
    }
}