如何在Eclipse IDE中调试Drools（.drl）文件

Question

I have a Java Spring project which calls drl file. While debugging, I want to see which rule is running and which condition is getting passed or failed. I am using Drools 5.3.0.Final runtime.

Please help me in debugging drl files.

Answer 1

I'm not sure what the Eclipse plug-in of your version (5.3.0 is quite outdated) is capable of providing wrt debugging consequences. You might try to add an event handler, set a breakpoint in Java code on the handler for BeforeMatchFiredEvent, see what rule is about to fire and, eventually, step on from there.

As for seeing conditions passing or failing: perish the thought. Evaluation of conditions is a complex process, happening at odd times. Watching this code being executed isn't available, and if it were, chances are that it would confuse you more than provide enlightenment.

For debugging complex conditions - say on a rule with N patterns - you might add rules containing pattern 1, then patterns 1 and 2, patterns 1, 2 and 3, etc, to learn what succeeds and what fails. (To simplify this, you may make use of the "extends" clause of a rule.)