CWA 16008-1:2009

J/eXtensions for Financial Services (J/XFS) for the Java Platform - Release 2009 – Part 1: Base Architecture - Programmer's Reference

Scope

J/XFS defines a standardized interface to all common financial devices which can be used by applications and applets written in the Java programming language. One of the reasons why these new banking applications are written in the Java language is that these programs are supposed to run on many different hardware platforms. One of the main obstacles in doing platform independent programming is accessing devices.
One of the main goals of this standard is to allow access to banking devices in a 100% pure Java way on both thin and thick clients, e.g. on a network computer as well as in a Linux, Windows, OS/2 or Unix workstation.

Another goal is to allow the remote access to devices on different machines. Additional efforts have to be done to find and access these devices. This is the main reason why central administration processes and an additional communication layer are also defined by this architecture.
If only local access to devices is needed, an implementation may omit this communication layer. No change is required to the Device Controls or Device Services. So, neither the application programmer nor the hardware manufacturer who programs a Device Service need be aware of whether or not a communication layer exists in the middle.

Due to the nature of network computers which are supported as clients, it is not possible to guarantee that local persistent storage possibilities exist on each client. Therefore, any configuration information must be kept on a central server. If local storage exists and no central configuration possibilities are required, all configuration information can also be kept on the local workstation.

The basic architecture of J/XFS is similar to the JavaPOS architecture. It is event driven and asynchronous.
Three basic levels are defined in JavaPOS. For J/XFS this model is extended by a communication layer, which provides device communication that allows distribution of applications and devices within a network.