Persistence of events
by Maciej Prochniak
Hello,
Is it possible to persist events (from drools fusion) with default jpa
mechanism? When I try to do this 'just like that' I get exception
like
org.drools.common.DefaultFactHandle incompatible with
org.drools.common.EventFactHandle
It seems that session marshaller is not really aware of certain objects
being events, not facts.
The code I try is more or less like:
UserTransaction ut = ...
StatefulKnowledgeSession session = JPAKnowledgeService
.newStatefulKnowledgeSession(kbase, null, env);
ut.begin()
session.insert(e1);
ut.commit();
StatefulKnowledgeSession sessionPersisted =
JPAKnowledgeService.loadStatefulKnowledgeSession( session.getId(),
kbase, null, env );
ut.begin()
sessionPersisted.insert(e2); (*) <- fails
ut.commit();
When I use session instead of sessionPersisted - it works fine, when
e2 is a fact, not an event - it also works
I know that it may be awkward to persist events which have time
limitations, but I want to use time limits in rules which are like few
days - so I want to have some persistence in case of server shutdown.
I would be grateful for any comment,
br,
maciek prochniak
14 years, 5 months
Log4j in the rules?
by granz＠MIT.EDU
Hi,
Is it possible to use Log4j inside the rules (RHS)?? (drl file)
Thanks,
Fabrice
14 years, 5 months
Drools-Fusion : Inserting an Event in to an "entry-point" stream in the RHS of a rule?? Pls help
by Chetan Mahadev
Hi
Can we insert an Event in the RHS part of a rule to an entry-point?
basically i am trying to do this. Pls let me know if this is possible? if
not any alternative approaches? Any example would be useful pls
declare TransactionEvent
@role( event )
end
$tmp : TestClass()
$tmp.message == "TRUE"
then
TransactionEvent ev1 = new TransactionEvent (); // This should be
inserted in to an entry-pont "Temporal Reasoning" stream
ev1.setMessage("Temporal Reasoning")
insert (ev1) to entry-point "Temporal Reasoning"
end
rule "Temporal Reasoning"
$tmp : TransactionEvent ( message== "Temporal Reasoning") from entry-point
"Temporal Reasoning"
then
System.out.println("Rule fired due to entry point ");
end
Regds
Chetan
14 years, 7 months
How to Access and Execute Rules from Database
by Ashish Soni
Hi All ,
I am able to configure oracle database in drools but now i am not able to
find how can i load rules from the DB and execute them , I gone through the
documentation but not able to get much information or might be i am missing
something.
If any one can provide me a example or some pointer ,hints then it would be
helpful.
Regards,
Ashish
14 years, 7 months
unable to determine operator for symbol [before]
by vladimiro
Hi all,
I'm building a KnowledgeBase with KnowledgeAgent and a precompiled
rule package. When the package contains a rule using temporal operators
such "after" or "before" I get the exception listed at the end of this
message.
I'm using the latest version of drools 5 and my runtime configuration
includes the following libraries:
* drools-core - the rule engine itself.
* drools-api
* mvel2-2.0.10
* joda-time-1.6
the rule causing such a behaviour is:
rule 'Test2'
dialect 'mvel'
when
u1:UserType( firstName=="UserA" )
lie:UserEventType( event=="Login", user.id==u1.id)
loe:UserEventType(event=="Logout", user.id==u1.id, this before lie)
then
Message msg = new Message();msg.setText("Test2
fired");driver.getMessages().add(msg);
end
java.lang.RuntimeException: KnowledgeAgent exception while trying to
deserialize KnowledgeDefinitionsPackage
at
org.drools.agent.impl.KnowledgeAgentImpl.rebuildResources(KnowledgeAgentImpl.java:418)
at
org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentImpl.java:120)
at
org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentImpl.java:109)
at
info.vladimiro.tesi.peservice.KnowledgeBaseService.<init>(KnowledgeBaseService.java:94)
at
info.vladimiro.tesi.peservice.KnowledgeBaseService.getInstance(KnowledgeBaseService.java:65)
at
info.vladimiro.tesi.peservice.PEListener$KBTask.run(PEListener.java:35)
at java.util.TimerThread.mainLoop(Timer.java:512)
at java.util.TimerThread.run(Timer.java:462)
Caused by: org.drools.RuntimeDroolsException: unable to determine
operator for symbol [before]
at
org.drools.base.evaluators.Operator.determineOperator(Operator.java:71)
at org.drools.base.evaluators.Operator.readResolve(Operator.java:106)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at
java.io.ObjectStreamClass.invokeReadResolve(ObjectStreamClass.java:1033)
at
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1728)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1305)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at org.drools.base.BaseEvaluator.readExternal(BaseEvaluator.java:53)
at ...
Can someone help? Thanks in advance.
Vladimiro Corsi
14 years, 9 months
StatefulKnowledgeSession Vs StatefulSession
by DeepakA
I used a KnowledgeBuilder ro read the resources (DSL & DSLR files)
Then created a KnowledgeBase and created a StatefulKnowledgeSession out of
the KnowledgeBase.
The StatefulKnowledgeSession was used to start the process and fire all
rules.
Then I realized I was not able to access the RuleBase from
StatefulKnowledgeSession.
So, now I create a RuleBase, then a PackageBuilder, add the resources to the
packageBuilder, then add the
package to the RuleBase and create a StatefulSession out of the RuleBase.
This statefulsession is used to start the process and fire all rules.
Can someone explain to me whats the difference in the above 2 methods of
firing the rules.
Whats the difference between StatefulKnowledgeSession & StatefulSession.
--
View this message in context: http://old.nabble.com/StatefulKnowledgeSession-Vs-StatefulSession-tp26511...
Sent from the drools - user mailing list archive at Nabble.com.
14 years, 11 months
[Urgent] Error in ontext assist in DSLR Editor
by hamza bakkali
Hi All,
I have been using drools 4 for couple of months now and I am starting to get
the hang of it. We recently decided to move to Dools 5 with Eclipse 3.4.2
(Ganymede).
We unfortunately hit a major 'show stopper' (for us). In the DSLR editor:
Context Assist + space + enter removes/replaces the whole line, not only the
place holder.
In other words:
DSL:
[*][]Log : {msg}=System.out.println("{msg}");
[*][]id1="some id label"
DSLR:
rule "MyRule"
when
then
end
If I Press L , control space --> the line Log:{msg} appears in the context
menu. Hit enter I get
Log :{msg}
Now, If want to replace msg by id1. I position the cursor in the {msg}, hit
ctrl space, id1 shows in the list. I hit enter the whole line disappear, and
I am left with
id1
instead of
Log : id1
Is this a setting somewhere in eclipse itself?? I doubt it.
The same thing use to work as expected in Drools 4.
thanks.
14 years, 11 months
About for and inheritance
by Chris Woodrow
Hi,
I recently find out a few issues using for, and I wanted to share it with
you. I made a simple exemple to illustrate my purpose.
My classes are (I did not represent accessors & constructors):
public class Cheese {
protected String name;
}
public class FrenchCheese extends Cheese{
private String smell;
}
public class Person {
private Cheese likes;
}
Here is my rule set :
package rules
rule "likes cheese"
when
$person : Person ()
Cheese( ) from $person.getLikes()
then
System.out.println("likes cheese");
end
rule "likes french cheese"
when
$person : Person ()
FrenchCheese( ) from $person.getLikes()
then
System.out.println("likes french cheese");
end
First test :
Cheese cheese = new FrenchCheese("good", "camembert");
Person person = new Person();
person.setLikes(cheese);
Output :
likes french cheese
likes cheese
Wich is expected...
Second test :
Cheese cheese = new Cheese();
Person person = new Person();
person.setLikes(cheese);
Output :
likes french cheese
likes cheese
That's the first strange thing. As far as I am concerned, rule "likes french
cheese" should not match (since a Cheese is not a FrenchCheese).
I made a change to the second rule :
rule "likes french cheese"
when
$person : Person ()
FrenchCheese( smell == "good" ) from $person.getLikes()
then
System.out.println("likes french cheese");
end
Third test :
Cheese cheese = new Cheese();
Person person = new Person();
person.setLikes(cheese);
output :
It throwed an exception : Exception in thread "main"
java.lang.ClassCastException: rules.Cheese
I am not saying the ClassCastException is not to expect in such a case but I
think I would simply expect it not to match (as far as a Cheese is not a
FrenchCheese).
Chris
15 years, 1 month
