This example demonstrate how to retrieve list of files from FTP server. First we create an instance of org.apache.commons.net.ftp.FTPClient. Connect to the FTP server and login with your username and password.

The listFiles() method of the FTPClient return the list of filenames contained in the current working directory. null if the list could not be obtained. If there are no filenames in the directory, a zero-length array is returned.

package org.kodejava.example.commons.net;

import org.apache.commons.io.FileUtils;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;

import java.io.IOException;

public class FTPListDemo {
    public static void main(String[] args) {
        FTPClient client = new FTPClient();

        try {
            client.connect("ftp.example.org");
            client.login("admin", "admin123**");

            if (client.isConnected()) {
                // Obtain a list of filenames in the current working
                // directory. When no file found an empty array will
                // be returned.
                String[] names = client.listNames();
                for (String name : names) {
                    System.out.println("Name = " + name);
                }

                FTPFile[] ftpFiles = client.listFiles();
                for (FTPFile ftpFile : ftpFiles) {
                    // Check if FTPFile is a regular file
                    if (ftpFile.getType() == FTPFile.FILE_TYPE) {
                        System.out.printf("FTPFile: %s; %s%n",
                            ftpFile.getName(),
                            FileUtils.byteCountToDisplaySize(ftpFile.getSize()));
                    }
                }
            }
            client.logout();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                client.disconnect();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

Here is the example result of our code:

Name = .
Name = ..
Name = .data
Name = example.html
Name = Touch.dat
FTPFile: .data; 1 KB
FTPFile: examples.html; 1 bytes
FTPFile: Touch.dat; 0 bytes

Maven Dependencies

<!-- http://repo1.maven.org/maven2/commons-net/commons-net/3.6/commons-net-3.6.jar -->
<dependency>
    <groupId>commons-net</groupId>
    <artifactId>commons-net</artifactId>
    <version>3.6</version>
</dependency>
<!-- http://repo1.maven.org/maven2/commons-io/commons-io/2.5/commons-io-2.5.jar -->
<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.5</version>
</dependency>

• About
• Latest Posts

Wayan Saryada

Founder at Kode Java Org

I am a programmer, a runner, a recreational diver, currently live in the island of Bali, Indonesia. Mostly programming in Java, Spring Framework, Hibernate / JPA. You can support my works by donating here. Thank you 🥳

Latest posts by Wayan Saryada (see all)

• How do I clear the current command line in terminal? - February 14, 2019
• How do I generate random alphanumeric strings? - February 7, 2019
• Why do I get ArrayIndexOutOfBoundsException in Java? - January 29, 2019