Hi,

 

First time posting in the mailing list, so I apologise if I make any silly mistakes.

 

I have two classes MachineOnline and MachineOffline, which denote when a machine is online and offline respectively

 

public class MachineOnline {

    int machineId

 

}

 

 

These are declared in the drl file as events, so Drools Fusion automatically generates the timestamp for me (I am running in STREAM mode, so i get real time updates on the machine status)

 

declare MachineOnline

    @role(event)

end

 

I then have a rule to generate the duration when the machine is online, but I cannot seem to extract the timestamp that drools automatically inserts. A thread a few years ago suggested using .startTimestamp, but Drools does not seem to recognise it as a field. I believe that needs an EventFactHandle, but I'm not sure how to retrieve that inside the drl file.

 

rule "Find duration machine is online"

    when $message1 : MachineOnline()

             $message2: MachineOffline(machineId == $message1.machineId && this after $message1) // + more rules to handle edge cases

    then

         //processing

         duration = $message2.startTimestamp - $message1.startTimestamp ?

end

 

The eventual aim is to allow for a query that allows me to find how long the machine is online for during a specified time interval, so if there is a way to do this without needing to retrieve the actual timestamp of each event, that will be great too. Or would it be better to manually define a timeStamp field for each event? I've been using the default one as that together with the pseudo allows for easy unit testing.

 

Thanks a lot!

 

Regards

Jing