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

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(a)yahoo.com&gt; wrote: