Classloading error with AspectJ and Drools 5.2.0.Final
by Steven Williams
Hi,
I have just upgraded to Drools 5.2.0.Final and am getting a weird error when
running unit tests.
java.lang.NullPointerException
at org.aspectj.weaver.loadtime.ClassLoaderWeavingAdaptor.parseDefinitions(
ClassLoaderWeavingAdaptor.java:251)
at org.aspectj.weaver.loadtime.DefaultWeavingContext.getDefinitions(
DefaultWeavingContext.java:130)
at org.aspectj.weaver.loadtime.ClassLoaderWeavingAdaptor.initialize(
ClassLoaderWeavingAdaptor.java:161)
at
org.aspectj.weaver.loadtime.Aj$ExplicitlyInitializedClassLoaderWeavingAdaptor.initialize(
Aj.java:271)
at
org.aspectj.weaver.loadtime.Aj$ExplicitlyInitializedClassLoaderWeavingAdaptor.getWeavingAdaptor(
Aj.java:276)
at org.aspectj.weaver.loadtime.Aj$WeaverContainer.getWeaver(Aj.java:254)
at org.aspectj.weaver.loadtime.Aj.preProcess(Aj.java:90)
at org.aspectj.weaver.loadtime.ClassPreProcessorAgentAdapter.transform(
ClassPreProcessorAgentAdapter.java:54)
at sun.instrument.TransformerManager.transform(TransformerManager.java:169)
at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:365
)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at org.drools.rule.JavaDialectRuntimeData$PackageClassLoader.fastFindClass(
JavaDialectRuntimeData.java:570)
at org.drools.util.CompositeClassLoader$CachingLoader.load(
CompositeClassLoader.java:258)
at org.drools.util.CompositeClassLoader$CachingLoader.load(
CompositeClassLoader.java:241)
at org.drools.util.CompositeClassLoader.loadClass(
CompositeClassLoader.java:88)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
at org.drools.rule.JavaDialectRuntimeData.wire(
JavaDialectRuntimeData.java:405)
at org.drools.rule.JavaDialectRuntimeData.wire(
JavaDialectRuntimeData.java:396)
at org.drools.rule.JavaDialectRuntimeData.onBeforeExecute(
JavaDialectRuntimeData.java:237)
at org.drools.rule.DialectRuntimeRegistry.onBeforeExecute(
DialectRuntimeRegistry.java:132)
at org.drools.compiler.PackageBuilder.reloadAll(PackageBuilder.java:796)
at org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:751)
at org.drools.compiler.PackageBuilder.addPackageFromDrl(
PackageBuilder.java:360)
at org.drools.compiler.PackageBuilder.addKnowledgeResource(
PackageBuilder.java:538)
at org.drools.builder.impl.KnowledgeBuilderImpl.add(
KnowledgeBuilderImpl.java:28)
at au.com.promedicus.rules.KnowledgeBaseBuilder.addPackagesFromList(
KnowledgeBaseBuilder.java:108)
at au.com.promedicus.rules.KnowledgeBaseBuilder.build(
KnowledgeBaseBuilder.java:69)
at au.com.promedicus.rules.KnowledgeBaseBuilder.build(
KnowledgeBaseBuilder.java:54)
I have traced the problem to org.drools.rule.
JavaDialectRuntimeData$PackageClassLoader.getResources. This returns null
whereas AspectJ expects it to at least return an empty enumeration - hence
the NPE. Interestingly the problem does not occur when running our server,
however we can't upgrade unless our unit tests pass and we can't easily turn
off aspectj for these.
regards
Steve
14 years, 6 months
Druplicate rule name: 0
by bitter
I have 100 rules in xls decision table.
I modify any rule and save change. Then I try to build create new knwoledge
base using this file and I have exception:
java.lang.RuntimeException: [784,0]: Duplicate rule name: 0
[801,0]: Duplicate rule name: 0
[818,0]: Duplicate rule name: 0
[837,0]: Duplicate rule name: 0
[856,0]: Duplicate rule name: 0
[873,0]: Duplicate rule name: 0
[890,0]: Duplicate rule name: 0
[907,0]: Duplicate rule name: 0
[924,0]: Duplicate rule name: 0
[941,0]: Duplicate rule name: 0
[958,0]: Duplicate rule name: 0
[975,0]: Duplicate rule name: 0
[992,0]: Duplicate rule name: 0
[1009,0]: Duplicate rule name: 0
I tried to compile this file using SpreadSheetCompiler. This is a scrap of
drl file wth rules:
*
# rule values at A52, header at A5
rule "0"
salience 60
ruleflow-group "0"
when
*
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14 years, 6 months
How to deploy Fusion ?
by eskomk
Hi all,
I'm new to Drools.
We need to have Fusion features in our systems, especially temporal
relations on events.
The problem is we don't know how to take Fusion in use.
Our rules do not fire, why ?
What are the steps to get Fusion up and running ?
We are using Drools as a web service, and it is fed with xml-formed facts
through REST interface.
Drools itself works ok.
We use Guvnor as rule editor, and have its snapshot included as CHANGE_SET
resource in knowledge-services.xml, so that's not a problem.
The rules we are now interested in sits in separate .drl files which are
read as DRL resources in knowledge-services.xml
(file contents below, with BBBafterAAA.drl as a resource).
As I have understood, we must change to stateful session from stateless, to
use Fusion.
This is so that we can define the event processing mode as STREAM in
kbase-definition,
and clock-type as REALTIME in session-definition.
We are primarily using Drools version 5.1.1 on several physical and virtual
servers
(we are just learning Drools for now, primaliry gathering data to be used in
Drools).
Now I am testing Drools version 5.3.0-SNAPSHOT (drools-camel-server),
where the config file snippet below are taken.
<path> below replaces the actual package names.
We have declared some incoming facts to be events (never mind the Bean
ending):
declares_drl.drl
{file}
package org.test;
import <path>.AAABean;
import <path>.BBBBean;
declare AAABean
@role(event)
end
declare BBBBean
@role(event)
end
{/file}
File BBBafterAAA.drl contents, withot THEN part:
{file}
package org.test;
import <path>.AAABean;
import <path>.BBBBean;
/*
declare AAABean
@role(event)
end
declare BBBBean
@role(event)
end
*/
rule "BBBAfterAAA"
dialect "mvel"
no-loop true
salience 100
when
$Aaa : AAABean();
$Bbb : BBBBean(this after[10s, 10m] $Aaa);
then
// Consequences go here
{/file}
File knowledge-services.xml contents:
{file}
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:drools="http://drools.org/schema/drools-spring"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://drools.org/schema/drools-spring
http://drools.org/schema/drools-spring-1.3.0.xsd">
<drools:grid-node id="node1"/>
<drools:resource-change-scanner id="scanner" interval="2" />
<bean name="CCCInitBean" class="<path>.InitBean">
<property name="initOk" value="false"/>
</bean>
<drools:kbase id="kbase1" node="node1">
<drools:resources>
<drools:resource type="DRL" source="classpath:test.drl"/>
<drools:resource type="DRL"
source="classpath:declares_drl.drl"/>
<drools:resource type="DRL"
source="classpath:BBBafterAAA.drl"/>
<drools:resource type="CHANGE_SET"
source="classpath:ChangeSet.xml"/>
</drools:resources>
<drools:configuration>
<drools:event-processing-mode mode="STREAM"/>
</drools:configuration>
</drools:kbase>
<drools:kagent id="kagent1" kbase="kbase1" new-instance="false">
<drools:resources>
<drools:resource type="CHANGE_SET" source="classpath:ChangeSet.xml"/>
</drools:resources>
</drools:kagent>
<drools:ksession id="ksession1" type="stateful" kbase="kbase1"
node="node1">
<drools:configuration>
<drools:clock-type type="REALTIME"/>
</drools:configuration>
<drools:batch>
<drools:insert-object ref="mirellaInitBean"/>
<drools:fire-all-rules />
</drools:batch>
</drools:ksession>
</beans>
{/file}
Cheers,
Esko
http://www.ebsolut.fi
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14 years, 6 months
Newbie: Drools and this multi-user/domain scenenario realization
by Peter Schmidt
Hello all:
Being new to Drools, I'm currently uncertain if it's "a good idea" to use
Drools for the following "multi-domain" scenario.
-- I guess Drools is appropriate, but I currently can't imagine (a) which
Drools parts to configure after which strategies (static/cachable vs.
dynamic), and thus also (b) how to organize the rule structures and their
goals (what input/output, what is cachable).
The scenario is as follows:
A /Businesses Service/ *Java Web App* shall manage /N/ distinct shops for
/N/ distinct shop owners, thus having /N/ "domains" with their own fact
model (extended from basic model that is the same for all shops), their own
rules, etc.
The shared but extensible 'Product' model is for rather *static* product and
product set definitions, and it basically consists of:
(a) some basic attributes (product name, description, etc.) AND
(b) several custom (=dynamic) attributes, independly definable by each
shop owner (attrib name, type, value(s)).
Non-technical shop owners define their products, "product sets", customer
types, and last but not
least use the "price model" to assign prices to products and product sets,
depending on some fixed
(e.g. customer_type ::= {NEW_CUSTOMER, REGULAR_CUSTOMER, VIP,...}, taxes,
etc.) and probably some custom price aspects like:
- quantity ranges,
- charges for a specific dyn. product attribute (e.g. t-shirts of
'size==XXL' => +10% of basic price),
- additional promotional price discounts (or charges) for specific
products or sets.
Product defs and taxes are rather /static/ once created, whereas prices and
discounts are /highly dynamic/, i.e. should be externally changeable at need
by the non-technical shop owners (IMHO /decision tables/ are the most
appropriate way here).
Customers are presented a shop's Online Catalog (or Ordering Form) showing
the prices intended for them, of course, but probably also the other
customer-type specific prices -- for them to see their current savings or
the possible savings after a customer-type "upgrade".
Finally, customers place orders via the web interface and the system
processes these orders (via further rules). ...
My unclarities are:
For the rather static "product (set) definitions" (both type def & instance
data),
Should I better use a traditional way via *configuration files* OR
could I use Drools with
some kind of "product definition rules" (generated from /decision
tables/)???
What is a good strategy for realizing the "product def rules" in
Drools? I.e.,
What is static and what dynamic? What is generated once vs. in
real-time, and what is cached vs. physically stored in the database?
For the highly dynamic "price assignments" (after some pre-defined as well
as custom pricing aspects):
How could a pricing table with custom pricing parameters look like? OR
equivalently:
How to define a pricing rule that dependens on a custom product
attribute?
The intention is similar to:
WHEN ( aProduct.extendedAttributes.size == 'XXL' )
THEN ( aProduct.price = aProduct.standardPrice * 1.10 ) //+10% of std.
price
When would the defined pricing rules run and what would they generate?
-- I.e., will all rules re-run each time a rule file changes with the
goal of generating cacheable "price lists", or will they even run on any
catalog request (thus generating the price lists on-the-fly)???
In such a not so uncommon JavaEE Web App shopping scenario:
Generally, which kind of rules are feasible besides the "product (set)
definition" and "price controling" rules?
I guess rules such as the following could be practicable:
fact model type definition rules (that construct and load new model types).
GUI generation rules for Swing/SWT and Web GUIs (after some
type-to-component mappings configured via rules or decision tables).
authentication & authorization rules.
Knowing the required artefacts and their generation strategies (cached vs.
life) from the answers of the above questions:
How do I have to configure Drools (& Guvnor) for *N parallel running* online
shops? I.e.,
Do I instantiate 1 rule engine per shop, or do I share 1 for all shops?
Do I load the generic fact model (that supports custom enhancements) once
per shop, or share it among them?
Which parts can be cached in "Application Scope"? (supposable N
KnowledgeBases with pre-generated stuff, 1 for each shop)
In which kind of JEE Session Beans do I have to integrate which kind of
Drools Knowlege Session beans?
The clarification of these issues would currently help me a lot.
Thank you very much for any help and development hints in advance.
Best regards
Peter
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14 years, 6 months
Bulk modification
by Rodrigo Goncalves
Hi,
How can I modify all objects resulted from a collect operation?
I would like to do something like this: (The following does not work)
rule "test"
when
exists (MyClass());
$l : ArrayList() from collect (MyClass (attribute == false));
$r : AnotherClass();
then
$r.doSomething($l);
for(Object o : $l) {
MyClass o2 = (MyClass) o;
modify(o2) { setAttribute(true); } ;
}
end
I do not want to do:
rule "test"
when
$o : MyClass(attribute == false)
$r : AnotherClass()
then
$r.doSomething($o);
modify(o) {setAttribute(true);};
end
because I need to do a bulk operation… Doing it one by one is extremely inefficient in my case.
Thanks!
Rodrigo.
14 years, 6 months
Trapping runaway rules
by Dean Whisnant
My project involves rule creation by customers, business analysts, and developers. We have a base set of rules that fire for every transaction and then we fire custom rules within a stateful session. An issue I've started to run into is rules being created that fire endlessly. I initialize the session with an event listener that we use to extract all rules fired for each line item of a transaction. Once the session is initialized and all rules from various agenda groups loaded we do a fireall rules.
My questions are:
1) how can I detect I have a runaway rule/rules.
Is there a method or listener that could detect this for me? Does anyone have a formula they use to do so? I had thought that I could use my event listener that I track the rules with to grab the last X number of rules fires and see if rule y gets fired more that z times. But is there a simpler method?
2) once I've detected a runaway rule, how can I gracefully stop drools rule execution? I read of the command drools.halt in different posts, but not sure if this would be what I'm looking at doing.
Any thoughts are appreciated.
Thank you!
Dean
StatefulKnowledgeSession ksession = buildOutgoingStatefulKnowledgeSession(supportingUDTList);
// AgendaEventListener agendaListener = new HipaaAgendaListener();
ksession.addEventListener(_ruleLog);
for (int i = 0; i < _agendaGroups.size(); i++)
{
if (_log.isDebugEnabled()) _log.debug("Focus on Agenda Group " + _agendaGroups.get(i));
ksession.getAgenda().getAgendaGroup(_agendaGroups.get(i)).setFocus();
// Fire them all
try
{
ksession.fireAllRules();
}
catch (Exception e)
{
_log.error("FireAllRules exception. Error=" + e.getMessage()); // error
}
}
14 years, 6 months
accessing items from the StatelessKnowledgeSession
by Warner Onstine
I have passed in some lists into the
StatelessKnowledgeSession.execute() method and would like to figure
out how to get access.
I have the following items passed in:
- Player
- EarnedBadges (list)
- Badges (list)
and am trying to do something like this:
not (EarnedBadge(playerId == $player.id, badge == $badge) from $earnedBadges)
but it doesn't know how to evaluate earnedBadges (the name of the
variable I passed in):
[Unable to Analyse Expression $earnedBadges:
[Error: unable to resolve method using strict-mode:
java.lang.Object.$earnedBadges()]
[Near : {... $earnedBadges ....}]
Been searching through the docs on how to do this but I haven't found
anything yet.
Any help is greatly appreciated, thank you! :-).
-warner
14 years, 6 months
Getting one type from a collection of multiple types
by lhorton
The following code works, but I think it's ugly.
the classes are:
DescribedAddress is a base class for addresses
VendorAddress extends DescribedAddress and implements method abcScore()
Step getLocations() is defined as a list of DescribedAddress objects but it
can also contain VendorAddress objects since they are a kind of
DescribedAddress
the LHS of the rule below extracts the VendorAddress with the highest
abcScore from step.locations
if I omit the eval(), i get ClassCastException on any DescribedAddress in
locations, since DescribedAddress cannot be cast to VendorAddress.
is there a more elegant / clean / efficient way to get only the
VendorAddress objects from locations?
rule "Find highest scored address"
dialect "mvel"
when
$step : Step()
$location : VendorAddress (eval($location instanceof VendorAddress ),
abcScore>9) from $step.getLocations()
not $addr : VendorAddress (eval($addr instanceof VendorAddress
),abcScore > $location.abcScore) from $step.getLocations()
then
System.out.println("high score is: " + $location.getAbcScore());
end
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14 years, 6 months
