Drools
jboss Rules Engine
In order to use the (amazingly cool) Drools rules engine in a .NET world, you've got to figure out how to pass your .NET business object over there to the land of Java. There are a couple of ways to do this. I wanted a straightforward way that didn't rely on any 3rd party tools. Here's the gist of what we're trying to accomplish:
Instantiate a .NET object; populate with values.
Serialize the object and send it to a queue.
Java application monitors the queue; picks up the message text.
...
Setup of a Drools development environment is fairly straightforward. (For a Java app.) For this exercise, I'm going to kick open Microsoft Virtual PC 2007, and start with a new instance of Windows XP Pro SP3.
First, install Java. Go to the Get Java link, and install the latest version, which at the time of this writing is Version 6 Update 12. Depending on your browser settings, you might have to download the file (jxpiinstall-6u12-fcs-bin-b04-windows-i586-17_jan_2009.exe) and run it locally. Whatever. The point is to step out and get Java on your machine.
Second, install the Eclipse IDE for Java EE Developers. ...
So I admit to you right from the start: this is something of an odd journey to undertake. Speaking with colleagues over the years, my own experience is that most developers raise an eyebrow and cast a wary eye toward anything labeled a 'rules engine'. And in fact, it does take a very specific set of requirements to lead to the conclusion that a rules engine is appropriate.
This dude and this other dude supply a good summary of why an organization might decide on going with a rules engine.
So once you decide a rules engine is an appropriate solution,...