Drools Post 1 - What is Drools

The website says Drools is a Business Rule Management System, but well what is that. It also talks about the Rete algorithm, which you can look up at wikipedia [Wikipedia:Rete_algorithm]. As I said I bought a book to get the answers. Jeremy Ary says that "Drools is a collection of tools which allow us to separate and reason over logic and data found within businss processes". He continues that this is quite not the answer someone wants to get - just from my point of view - he is right :-).

So one important thing that we have are rules. And well we want to use these rules to build a rule-driven system. More precisely we want to tell our system how to react if some conditions are fulfilled. For example throw an event, inform someone or just shutdown. If a condition is fulfilled depends on the data, the facts of the world. Sometime the knowledge of a new fact results in another fact, that results in new fulfilled conditions.

So summarized, Drools enables us to define rules that are executed by the rule engine. The rule itself is not part of the code... but it uses facts or data that is derived from it. So the logic is extracted from our code, as long as it is rule-oriented logic. Sounds nice. So lets get started...