Few rules, many facts
by Yuri de Wit
I am working on a drools application with few rules and large number
of facts. In my first design I tried to avoid excessive joins thinking
I was helping improve performance but didnt realized that I was
actually shooting myself in the foot. I was basically creating a
single facade-fact that would contain two or three diff concerns
joined under the same interface. The problem I am seeing is that for
simple things like changing the status of one of many facts would
cause that fact to be reevaluated against all the other facts.
I then realized that thinking relationally about the problem would not
only simplify my solution but also probably make a lot faster.
However, in this new and relational solution I will need to make use
of many "not" CE.
My question is: is there any cost in using "not"s that I should be
awae of? Any other words of wisdom re: improving the performance in
small rules x many facts?
thanks,
-- yuri
19 years
Rules question
by Yuri de Wit
Is it possible to do something like this with Drools 4.0?
rule
when
p:Parent()
not Child( this in p.children )
then
...
end
I basically dont want to keep a reference fro Child to Parent.
thanks,
19 years
Issue with not Fact equality checks?
by Eric Miles
I have a single rule in my test bed as such:
rule "5th Item Not Test"
when
$first : FirstClass($i1 : item1, $i2 : item2, $i3 : item3, $i4 :
item4, $i5 : item5)
not SecondClass(item1 == $i1, item2 == $i2, item3 == $i3, item4 ==
$i4, item5 == $i5)
then
System.out.println("NOT test matched");
end
In the not SecondClass() section of the test, the last equality checks
always fail, no matter what it is. I can switch the order around of the
checks, no matter what the last 2 are, they cause THEN clause to not
fire, even when I am absolutely positive there is not a match. (I can
remove the not and the equality works fine). Is there a limit on the
number of equality tests I can do with a not? It seems as though it is
4. I have attached a test case that can reproduce this (it is different
from my project's code, but I have been able to reproduce this in
multiple projects). It is a maven Eclipse project and includes a junit
with some minor instructions. If these instructions do not make sense,
please email me.
19 years
JBossRules and JAVA Servlet / JSP (part2)
by Mohammed JBossRules
2007/7/20, Mohammed JBossRules <jboss.lakehayli(a)gmail.com>:
>
> Hi,
> an other question , when i'm trying to execute the same code in the sample
> test java file provided by the wizard, I get some other errors :
>
> java.lang.NoClassDefFoundError: org/drools/WorkingMemory
> at java.lang.Class.getDeclaredConstructors0(Native Method)
> at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
> at java.lang.Class.getConstructor0(Unknown Source)
> at java.lang.Class.newInstance0 (Unknown Source)
> at java.lang.Class.newInstance(Unknown Source)
> at org.apache.catalina.core.StandardWrapper.loadServlet(
> StandardWrapper.java:1104)
> at org.apache.catalina.core.StandardWrapper.allocate(
> StandardWrapper.java:806)
> at org.apache.catalina.core.StandardWrapperValve.invoke(
> StandardWrapperValve.java:129)
> at org.apache.catalina.core.StandardContextValve.invoke(
> StandardContextValve.java:175)
> at org.apache.catalina.core.StandardHostValve.invoke(
> StandardHostValve.java:128)
> at org.apache.catalina.valves.ErrorReportValve.invoke(
> ErrorReportValve.java:104)
> at org.apache.catalina.core.StandardEngineValve.invoke (
> StandardEngineValve.java:109)
> at org.apache.catalina.connector.CoyoteAdapter.service(
> CoyoteAdapter.java:261)
> at org.apache.coyote.http11.Http11Processor.process(
> Http11Processor.java:844)
> at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process (
> Http11Protocol.java:581)
> at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java
> :447)
> at java.lang.Thread.run(Unknown Source)
>
>
> it works fine if i'm using a simple class, but when i try to use my
> servlet, it falls;
>
> and finally, is it possible to contribute withe a tutorial showing how to
> set up drools on eclipse and running a DroolsTest sample file,(arabic,
> english and frensh version) that's all i can propose for the moment.
>
> thank you.
>
>
>
>
>
>
> 2007/7/20, Mohammed JBossRules <jboss.lakehayli(a)gmail.com>:
> >
> > hello,
> > Thank you all for your replays; as you've suggested, what i should
> > import into my build path was not the core and compiler but all the set
> > contained in the drools library, maybe that would help someone later!
> > here is the list of jars
> > antlr-runtime.jar
> > drools-compiler.jar
> > drools-core.jar
> > drools-decisiontables.jar
> > drools-documentation.jar
> > drools-jsr94.jar
> > jsr94.jar
> > junit.jar
> > jxl.jar
> > mvel14.jar
> > xercesImpl.jar
> > xml-apis.jar
> > xpp3.jar
> > xstream.jar
> > Thankyou Mark for the link
> > with kind regards,
> >
> > ps: tried many times to post this mail yesterday but seems that it
> > doesn't work, sorry if you received it more than once!
> > Mohammed JBossRules wrote:
> > > Hello,
> > >
> > > I'm a new user for JBossRules, and I'm feeling like turning around
> > > since a while, so i thought that sole body could help...
> > > I'm using JBossRules( V4.0.0.12865MR3) on eclipse (Version: 3.3.0Build
> > > id: I20070621-1340) on MS-Windows XP and Java(TM) SE Runtime
> > > Environment (build 1.6.0_01-b06)
> > > now the problem is how to use my rules (simple rules in a DRL file) in
> >
> > > a dynamic project based on JSP/Servlets...
> > > i've imported the compiler, the core, jsr94, decisiontable, and also
> > > the core 3.2.3 jars to my build path , but when i try to execute the
> > > same code i'm having errors like:
> > > The import org.drools cannot be resolved
> > > but i have imported the core!!
> > > what's wrong? help please
> > >
> > > regards
> > > _______________________________________________
> > > rules-users mailing list
> > > rules-users(a)lists.jboss.org
> > > https://lists.jboss.org/mailman/listinfo/rules-users
> > >
> >
> >
>
19 years
BRMS import
by Shepherd, Michael
Hi,
Can I import an existing set of JBoss rules (Drools 3) into BRMS?
Thanks,
Mike
19 years
How to compare to Class type in LHS??
by Felipe Piccolini
Hi,
Im trying to compare a field to a Class type but when parsing I
get NPE and when I debug,
the constraint is a ReturnValueConstraint but the
restriction.getRequiredDeclarations()
return a Declaration[] array initializated, but empty, so I can't get
the declaration evaluated...
I needed because I'm working on a kind of parser for the rules for
analisys and testing... but using
the already parsed package.
Here is a pseudo rule for test...
rule "Test A"
when
$mf: MyFact(clazz == (SomeClass.class))
then
System.out.println("Test A: OK");
end
Actualy, the rule compiles (with the NPE output, not stackTrace, just
the java.lang.NullPointerException,
and it works fine.. I mean I get "Test A: OK" as output, but cant get
the SomeClass.class reference when I
look into the debugger.
Is this the right way to compare clases? if not, whats the right way?
(Im trying to not do == "SomeClass")
Felipe Piccolini M.
felipe.piccolini(a)bluesoft.cl
19 years
assertObject gone
by Jean Safar
Hi,
I download 4.0.0.MR3 and the examples do not compile anymore. In essence and
surprisingly, they try to call assertObject on a stateful session but this
method is nowhere to be found anymore.
Regards,
Jean Safar
19 years
Is this syntax correct?
by Shai Bentin
I need to fire a rule if I have more then one fact that has an endDate property from the last 24 months... is the follwoing correct?
rule "testing123"
when
olList: ArrayList(size > 1) from collect(CreditEventLocal(creditEventTypeVlId == "SOMETHING", $endDate: endDate -> ($endDate.after(DateUtils.addMonthsFromToday(-24)))))
then
System.out.println("eurika");
end
Anyhow, if it is then I get a NullPointerException which doesn't tell me what the problem is. It happens in building time of course:
I'm using drools4.0.0MR2
Exception in thread "main" java.lang.NullPointerException
at org.drools.rule.builder.dialect.java.JavaConsequenceBuilder.build(JavaConsequenceBuilder.java:53)
at org.drools.rule.builder.RuleBuilder.build(RuleBuilder.java:65)
at org.drools.compiler.PackageBuilder.addRule(PackageBuilder.java:353)
at org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:233)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:157)
at com.emi.framework.antTasks.PackageRules.addPackages(PackageRules.java:227)
at com.emi.framework.antTasks.PackageRules.execute(PackageRules.java:143)
at com.emi.framework.antTasks.PackageRules.main(PackageRules.java:325)
19 years
