posted 16 years ago
The first requirement is for the database layer. You have to implement a data access class implementing this interface. Therefore, you have to implement the methods as specified by the interface. The seoond requirement comes from the GUI or middle tier (depending on the design decision you choose). Therefore, these two do not have to match exactly. However, if you implement the method as specified in the interface your business method should not be a problem (as you stated yourself).
My suggestion would be to thing in different tiers or layers and develop them independently of each other.
Regards,
Thomas
SCJP 5.0, SCJD in progress