[rules-users] Eval0Invoker : java.lang.NullPointerException

[Michael Anstis]

Yikes!

This I had not even noticed.

Customer and ServiceContext should both be inserted as Facts.

Some rules might need to be re-written:-

rule "Customer null check rule"
no-loop true
salience 1000
       when
               not ( Customer() )
       then
               throw new MissingEntryFault("Customer is required");
end

rule "Service Context null check rule"
no-loop true
salience 1000
       when
               not ( ServiceContext() )
       then
               throw new MissingEntryFault("ServiceContext is required");
end

You must be inserting some (at least one) Customers in working memory
otherwise rules like this won't match anything:-

rule "PAN Device null or empty rule"
no-loop true
salience 300
       when
               $customer : Customer()
               $esi : ElectricServiceInterface() from
$customer.getElectricServiceInterfaces()
               eval( $esi.getPANdevices() == null ||
$esi.getPANdevices().size()<=0 )
       then
               throw new MissingEntryFault("PAN Device list cannot be null
or empty");
end

Which itself could be re-written removing the eval (I don't think you'll
get an NPE in the last "from"):-

rule "PAN Device null or empty rule"
no-loop true
salience 300
       when
               $customer : Customer()
               $esi : ElectricServiceInterface() from
$customer.getElectricServiceInterfaces()
               not ( PANDevice() from $esi.getPANdevices() )
       then
               throw new MissingEntryFault("PAN Device list cannot be null
or empty");
end


On 15 December 2011 16:03, Venkat <ven12344 at yahoo.com> wrote:

> Hi Manstis, I see what you are saying, and yes I not doing any update in my
> facts. If you see the rule file, there is global variable which defines the
> Customer and ServiceContext and also I am declaring the Customer object
> again in each rule.
>
> This is because I could not get those global variables access in other
> rules, can you tell me how to get those variables in other rules also.
>
> Thanks,
> Venkat.
>
> --
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