I am busy modeling a financial transaction system. In this system I have types of financial transactions like payments (representing purchases of an item) & refunds. Simple for this example.

I have modeled the domain like this so far:

Payment abstract class, inheriting from FinancialTransaction abstract class.
Sub classes like CCPaymemt, CashPayment, EFTPayment inheriting from Payment abstract class
Sub classes like CCRefund, CashRefund, EFTRefund inheriting from Refund abstract class

FinancialTransaction abstract class with subclasses Payment & Refund

I have a table per hierarchy mapping for Payments and a table per hierarchy for Refund with relevant hbm mappings.

I now need to create a FinancialTransaction mapping file that accounts for the Payment & Refund entities. What is the best way to do this? How do I create a the relevant mappings to Payment & Refund in the FinancialTransaction hbm mapping file?

Class diagram:


Hope this makes sense

S