Ftp-demo.java

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.SocketException;

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;

public class FileDownload {

    public static void main(String args[])
    {
        String server="ace.dev.demo";
        String user="user1";
        String pass="user1";
        int port=21;

        FTPClient client = new FTPClient();
        try {
            client.connect(server,port);
            client.login(user, pass);
            client.enterLocalPassiveMode();
            client.setFileType(FTP.BINARY_FILE_TYPE);


             String remoteFile2 = "qwert.txt";
                File downloadFile2 = new File("D:/Downloads/d.txt");
                OutputStream outputStream2 = new BufferedOutputStream(new FileOutputStream(downloadFile2));

                InputStream inputStream = client.retrieveFileStream(remoteFile2);
                byte[] bytesArray = new byte[4096];
                int bytesRead = -1;

                while ((bytesRead = inputStream.read(bytesArray)) != -1) {
                    outputStream2.write(bytesArray, 0, bytesRead);
                }

               boolean success = client.completePendingCommand();
                if (success) {
                    System.out.println("File #2 has been downloaded successfully.");
                }
                outputStream2.close();
                inputStream.close();


        } catch (SocketException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

}