What is XJFTP? : About the project

What is XJFTP?

An FTP Server, written in the Java Programming Language. It has a modular design (using Inversion of Control/Dependency Injection) using SpringFramework to allow pluggable JavaBeans to be used for handling the commands and processing the FTP data.

Why is XJFTP? : Why it was designed etc.

What's wrong with all the other FTP Servers?

The one major downfall with a traditional FTP Server, is it's dependency on the file system. In cutting-edge Enterprise Applications, you will usually have a large-scale database, ERP system or similar, where all the data is stored. This means that if you write incoming files to a disk, you then have to have some mechanism of getting them into your main application.

What are the other problems with FTP?

XJFTP was written to solve the problem of legacy FTP-based systems needing to transfer files to and from SOAs (Service Oriented Architectures) and Web Services solutions. It is written in such a way that there is absolutely no dependency on either web services or HTTP, you can plugin any underlying protocol you like, allowing FTP clients to access data in virtually any system.
The problem with using a conventional FTP server were:

• Too many accounts for a single sysadmin to maintain easily
• User accounts could not be authenticated easily against the new application
• Customers could not maintain their own passwords, increasing support costs
• Lack of Security inherent in the FTP protocol (account and data)
• Headaches maintaining firewall policies to allow FTP traffic
• Files stored on hard disks, which can fail. Even adding RAID isn't good enough for some applications
• Load balancing FTP servers is quite tricky, and expensive
• Files must be polling by the application, increasing complexity and adding a slight delay
• Many many more issues!

How does XJFTP help?

The FTP client user installs the XJFTP application, which you provide in addition to any web service or other protocol adaptor client you require to access your service.
The FTP-client application (e.g. a legacy system) is then configured to FTP files to and from this "local" ftp server, rather than it's ultimate destination (the central system).
Underneath the hood, XJFTP uses the protocol adaptor you have written to perform all the actions that your existing FTP server would have done. This includes account authentication, listing files on the server, and sending and retrieving files.
Your server application can then provide greater tracability, as it knows exactly where each uploaded file came from, as it has not just retrieved it from a somewhere on its local hard disk.
If HTTPS (either a web service, or proprietary application-level protocol) is used for the comms, then no firewall configuration is required to allow FTP in any direction, all you need is outbound HTTPS at the client's site, and inbound HTTPS at your site (which you probably already have).

What comes "in the box"?

A functional FTP server implementation, designed to run on all Java platforms with little or no configuration required.
An example "External Handler" (Emulating a Web Service), which you can turn on and off with a single config file change. This transforms the server from working with files, to working with Java Objects generated in memory.

Obtaining : How do I get XJFTP?

Where can I download XJFTP?

Requirements : What do I need to run it?

What Operating System?

XJFTP is written in Java, so should run on almost any OS. It has been developed under a combination of Windows and Linux, so it should work easily on these systems.

What else is required?

Installing : I have it, what now?

How to install XJFTP

Extract the ZIP/TAR.GZ file to directory on your computer. Run the xjftp.bat (Windows) or xjftp.sh (Unix/Linux) file to start up the server.

Running from the command line...

Run the following command java -Djava.ext.dirs=lib -jar xjftp-server.jar

Changing the configuration

There are 2 configuration files for XJFTP, one standard "properties" file, and for further customisations, the spring-config.xml file. More instructions on customising xjftp can be found in the documentation contained within the release.

Licensing : How can I legally use it?

About the License

Technical : What can I actually use it for?

What else could I do with XJFTP?

Some of the things I've thought of are:

• FTP Server backed by a CVS / Subversion Repository
• FTP ServerProxy, whereby the server actually delegates to another FTP Server via the Jakarta-Commons Net libraries for example

Techie FAQs : I'm a real geek and want to know the details!

What FTP features does XJFTP Support?

• Active and Passive (PASV) data transfers
• Configurable Port ranges for data ports, and the FTP server listening ports

The following standard FTP commands are fully implemented:
LIST, CWD, CDUP, STOR, RETR, as are many others, for full details, you'd better download the code and have a look

What about fancy features?

XJFTP does not aim to provide bandwidth throttling, quotas/ratios or any other complicated and rarely used features. It was originally designed to be an extremely lightweight FTP to Soap (Web Services) adaptor, but it was decided that it would be more beneficial to the open source community to provide an FTP to "any service" adapter.

The design : About the components

How is XJFTP designed?