JavaPOS is a retail industry standard framework for interfacing with POS terminal hardware devices. This includes such devices as:

New devices of the types already supported by the TE POS client (either from additional manufacturers or revisions from manufacturers already supported) should be able to be used with the client so long as the manufacturer provides a JavaPOS compliant driver that is version compatible with the client. All that is required is to configure the system appropriately with the new device.

Device Services is an additional software layer that sits between JavaPOS and POS client code and allows the client to interact with devices at a more abstract level. Since the POS client only interfaces directly with the Device Service layer, it is possible to write a device driver for a device that is not supported by a standard JavaPOS driver.

Device Services are “discovered” by the POS client at startup when it interrogates a configured set of Device Service Factories. You define the factory classes themselves in the device.properties file on the client. So by writing a custom factory (in addition to the Device Service itself), you can add a custom Device Service implementation to the system.