Re: [rules-users] Drools and ArrayList

[wendy]

Sorry I'm not quire sure I'm following your errors...

Are you saying you are having null pointer exceptions with this version:

global List list

rule "count from global List - but don't do it"
when
Number( $i: intValue ) from accumulate( Person( age > 20 ) from list,
count(1) )
then
System.out.println( $i + " Persons" );
end

--
View this message in context: 
http://drools.46999.n3.nabble.com/Drools-and-ArrayList-tp3140821p3158948.html
Sent from the Drools: User forum mailing list archive at Nabble.com.
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users

Re: [rules-users] Drools and ArrayList

[Wolfgang Laun]

This is how to do it - although it's not recommended to use globals in rule
conditions. (For one thing: the list must be complete before you call
fireAllRules().)

global List list

rule "count from global List - but don't do it"
when
Number( $i: intValue ) from accumulate( Person( age > 20 ) from list,
count(1) )
then
System.out.println( $i + " Persons" );
end

-W


On 6 July 2011 12:08, wendy  wrote:

> I think normally setGlobal variables are only used when you want to be able
> to call back out to the java code again. (I'm not an expert by any stretch
> so please take that with a grain of salt.) So you might be able to just
> insert the list.
>
> I'm going to assume the List is really List if that
> is
> not true please let me know.
>
> what about something like this?  First is collects all the
> NombersUnTypeDefault that match your constraints from list then it counts
> them using an accumulate function.
>
> global java.util.List list
>
> rule "Calcul redondance"
>   when
>   $i: Number() from accumulate($c: NombersUnTypeDefault()
>   from collect(NombersUnTypeDefault($code ==
> "AAA", $int == 1) from list)
>   , count($c));
>then
>   System.out.println($i);
> end
>
> --
> View this message in context:
> http://drools.46999.n3.nabble.com/Drools-and-ArrayList-tp3140821p3144161.html
> Sent from the Drools: User forum mailing list archive at Nabble.com.
> ___
> rules-users mailing list
> rules-users@lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users

Re: [rules-users] Drools and ArrayList

[wendy]

I think normally setGlobal variables are only used when you want to be able
to call back out to the java code again. (I'm not an expert by any stretch
so please take that with a grain of salt.) So you might be able to just
insert the list.

I'm going to assume the List is really List if that is
not true please let me know.  

what about something like this?  First is collects all the
NombersUnTypeDefault that match your constraints from list then it counts
them using an accumulate function.

global java.util.List list

rule "Calcul redondance"
   when
   $i: Number() from accumulate($c: NombersUnTypeDefault()
   from collect(NombersUnTypeDefault($code ==
"AAA", $int == 1) from list)
   , count($c));
then
   System.out.println($i);
end

--
View this message in context: 
http://drools.46999.n3.nabble.com/Drools-and-ArrayList-tp3140821p3144161.html
Sent from the Drools: User forum mailing list archive at Nabble.com.
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users

Re: [rules-users] Drools and ArrayList

[wendy]

Have you tried using the accumulate function?

//taken from the link below and modified a bit to use count.. (it is
untested)

rule "Count the number of items in the order"
when
$order : Order()
$total : Number( ) 
 from accumulate( OrderItem( order == $order),  count( ) )
then
 System.out.println("There are "+$total+ " number of items in the order");

end


http://docs.redhat.com/docs/en-US/JBoss_Enterprise_SOA_Platform/4.3/html/JBoss_Rules_Reference_Guide/ch05s05s02s10.html
 

--
View this message in context: 
http://drools.46999.n3.nabble.com/Drools-and-ArrayList-tp3140821p3141665.html
Sent from the Drools: User forum mailing list archive at Nabble.com.
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users