FTPClient 列举所有文件以及子目录下所有文件

    // FTPClient 列举所有文件以及子目录下所有文件。remotePath = "/" 表示 ftp 根目录
    public static List<String> listAllFiles(String hostname, int port, String username, String password, String remotePath) {
        FTPClient ftpClient = new FTPClient();
        List<String> result = new ArrayList<>();

        try {
            //连接FTP服务器
            ftpClient.connect(hostname, port);
            //登录FTP服务器
            ftpClient.login(username, password);
            //验证FTP服务器是否登录成功
            int replyCode = ftpClient.getReplyCode();

            if(!FTPReply.isPositiveCompletion(replyCode)){
                return null;

            }

            if (remotePath.startsWith("/") && remotePath.endsWith("/")) {
                FTPFile[] files = ftpClient.listFiles(remotePath);

                for (int i = 0; i < files.length; i++) {
                    if (files[i].isFile()) {
                        //print(files[i].getName());
                        result.add( remotePath + files[i].getName() );
                    } else if (files[i].isDirectory()) {
                        result.addAll( listAllFiles( hostname, port, username, password, remotePath + files[i].getName() + "/" ) );
                    }
                }
            }

            return result;

        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            if(ftpClient.isConnected()){
                try {
                    ftpClient.logout();
                } catch (IOException e) {}
            }
        }

        return null;
    }

调用

println( listAllFiles( hostname, port, username, password, "/" ) );