I have been designing this rule based medical billing system. I need to
map the rules so that addition/deletion of rules doesn't require code
change.
Example:
Rule 1:If patient age < 2 and patient_code > 100 then code=30000
Rule 2:If patient age >=2 then code=30000

I can define the elements in my XML document. But I am confused what
to do after that.
I need to extract the code and use this code for a database lookup to
get my final result.
The main requirement is: I shouldn't have to change any code in Java
program since all I need is the code.
I would like to get details on how to match rules and then extract the
code.
I looked at XML, DOM4J and other things. But I am really confused
since there is so much out there.

Please provide me a simple working example.
Thanks.
yogi

---

Request for Question Clarification by mathtalk-ga on 24 Nov 2002 07:19 PST

Hi, govindsri-ga:

I posted a comment to your question shortly after you posted it,
outlining one approach to using XML to maintain rules "outside" of a
Java code application.

Please review my comment on using XSLT in this connection.  I'm aware
that you want a simple working example, and basically propose that
without raising the list price, I might point you to such examples out
there on the Web.

I look forward to your reply!

regards, mathtalk-ga

Hi, govindsri-ga:

You are certainly right about there being "so much out there".  There
are probably innumerable ways to relate rules encoded in XML to your
data extraction Java function.

One way that occurs to me is to encode the XML rules in a specialized
kind of XML document known as XSLT.  You code extract data from the
database in the form of one XML document, then apply your rules as a
"transform" using the DOM (Document Object Model) or other tools.

If you would be interested in this sort of approach, I could post as
an answer some search strategies to help you locate working examples. 
You might want to review the Google pricing guidelines:

https://answers.google.com/answers/pricing.html 

if you desire a more elaborate response.

regards, mathtalk-ga