Message Abstraction

The Core-Host API abstracts the handling and message content into a set of java classes and interfaces. Channel activity is passed to the core as an event (for example, the authorise() method call). Message content is abstracted into entity classes. For example, EPSRequest/EPSCard and passed as arguments to those events. All the properties in the entity classes will have a directly related message element or attribute, and vice versa.

The message protocol specification should be used as the primary point of reference for how and when a particular property is used.