Well, smack me and call me silly.
I did not know you could extend interfaces multiple times, kind of like multiple
inheritance in C++. Solve a problem for me. But it makes a design question for
me.
For those who don't know, I am almost done with a 100% Java based CyberCash API,
which I'll be releasing to the community in a couple of weeks.
So, you have the scope of what I am trying to do here. And here is my design
problem.
I have 2 interfaces (comments stipped for brevity):
public interface CyberCashResponseIF {
public Properties getResponse();
public void setResponse(Properties response);
}
public interface CreditPaymentInformationIF {
public String getOrderNumber();
public String getCardType();
public String getCardZip();
public String getCardState();
public String getCardCountry();
public String getCardCity();
public String getCardNumber();
public String getCardName();
public String getCardExp();
public String getCardAddress();
public String getCardAmount();
}
These of course represent a response and request to a CyberCash Merchant server.
I used the names Cybercash does in their MCK documentation,
CreditPaymentInfomation = request in Cybercash lingo.
The Cybercash "engine" looks likes like this:
public class CyberCash extends Thread {
public CyberCash([MY DESIGN QUESION HERE] transaction) { }
public void run() {}
}
Because I extended Thread, I more or less have to pass everything in via the
constructor, so every cybercash transactions has a request and a response so
what I did what was this:
public interface CyberCashTransActionIF
extends CreditPaymentInformationIF, CyberCashResponseIF {
}
Changed Cybercash constructor to this:
public CyberCash(CyberCashTransActionIF transaction) { }
My question is: Is this a hack?
An interface that just extends 2 other interfaces just to combine them into a
nice "package" seem wrong to me OO desing side, but my old C-hack side says it
works, so do it.
Futher design details show that there are some object that just do
CreditPaymentInformation and other classes that just do CyberCashResponse, but a
majorit of them do both.
--
Bob Tanner <tanner at real-time.com> | Phone : (952)943-8700
http://www.mn-linux.org | Fax : (952)943-8500
Key fingerprint = 6C E9 51 4F D5 3E 4C 66 62 A9 10 E5 35 85 39 D9