| [news.eclipse.technology.ecp] JSR-94 Rules Engine API |
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This spec, http://www.jcp.org/en/jsr/detail?id=94,
details the minimum standard spec for a Java Rules Engine. Rules
engines are complex beasts and I personally hate them, but others think
they're better than sliced bread. There are many use cases for them
but one I'm familiar with is "Class of Service". A lot of businesses
group their customers into different 'classes' (right or wrong this is
just what they do). For a customer who buys a lot of @#$$^ from you on
a monthly basis may get a better class of service than Joe Blow who
only orders $10 every six months. So you set a discount rule that if
you spend over $50,000/month the previous month then you get 25% all
orders in the current month. You can also set a rule where if it is a
new account then you will automatically give a 10% discount on the 1st
order. You go on and on creating these Rules. What makes rules
engines so attractive, to some people, is the idea that they can be
manipulated by "Business" people without having to involved developers
to create and (un)deploy new rules, etc. Of course if you aren't
careful you can create rules that run into conflict. As for rules engines, I believe http://drools.codehaus.org/ and Jess are names I have heard of. Although I seem to remember something not really compatible about the Jess license/code. Wendell |