I am using org.apache.commons.net.ftp.FTPClient in one of my applications to work with a FTP server. I am able to connect, login, pwd
In my case, on top of applying enterLocalPassiveMode and indicating correct operation system, I also need to set UnparseableEntries to true to make the listFile method work.
FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_UNIX);
conf.setUnparseableEntries(true);
f.configure(conf);
boolean isLoginSuccess = client.login(username, password);