Discover when a rule isn't more active
by Claudio Rainoldi
Hi everyone,
isn'it there a way to find when a rule isn't more active.
For example if i have this rule:
rule "light 2 on"
dialect "java"
when
Light (name=="0/0/2", actualvalue=="1");
then
System.out.println("luce 2 on");
end
when someone turn on the light 2 i discover that the rule is fired using an
Agenda Event Listener and the method afterActivationFired;
But when someone turn off the ligth isn't there a similar way to discover
that the rule "light 2 on" isn't more active.
My only solution is to use the dual rule:
rule "light 2 on_dual"
dialect "java"
when
not (Light (name=="0/0/2", actualvalue=="1"));
then
System.out.println("luce 2 off");
end
Isn't there a more sample way to do this?
Thanks in advance.
Cla
18 years, 1 month
generic properties
by thomas kukofka
Hello ,
I just recognized, that this doesn't work. But it is possible to use plain
Java code in the rule, also if-conditions and for and while-loops etc..
However more Java code makes the rule less readable and elegant.
Is there another possibility to use generic input objects?
Thomas
18 years, 1 month
Problems building Package
by thomas kukofka
Hello,
I get the following Nullpointer exception when building the package:
java.lang.NullPointerException
at
org.drools.rule.AbstractCompositeRestriction.getRequiredDeclarations(AbstractCompositeRestriction.java:29)
at
org.drools.rule.MultiRestrictionFieldConstraint.getRequiredDeclarations(MultiRestrictionFieldConstraint.java:27)
at org.drools.rule.Pattern.setConstraintType(Pattern.java:279)
at org.drools.rule.Pattern.addConstraint(Pattern.java:157)
at org.drools.rule.builder.PatternBuilder.build(PatternBuilder.java:340)
at
org.drools.rule.builder.PatternBuilder.buildConstraint(PatternBuilder.java:199)
at org.drools.rule.builder.PatternBuilder.build(PatternBuilder.java:168)
at org.drools.rule.builder.PatternBuilder.build(PatternBuilder.java:93)
at
org.drools.rule.builder.GroupElementBuilder.build(GroupElementBuilder.java:69)
at org.drools.rule.builder.RuleBuilder.build(RuleBuilder.java:53)
at org.drools.compiler.PackageBuilder.addRule(PackageBuilder.java:446)
at
org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:304)
at
org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:167)
at
com.dssrules.RuleEngineAdapter.initRuleBase(RuleEngineAdapter.java:71)
at
com.dssrules.TestRuleEngineAdapter.main(TestRuleEngineAdapter.java:17)
Exception in thread "main" java.lang.NullPointerException
at com.dssrules.RuleEngineAdapter.insert(RuleEngineAdapter.java:42)
at
com.dssrules.TestRuleEngineAdapter.main(TestRuleEngineAdapter.java:35)
Debugging shows the programm get stuck in this line (the resource drl-file
was found):
* builder0.addPackageFromDrl(new
InputStreamReader(resource.getInputStream()));
I have further the error message: Missing package name for rule package."
Although the package declaration in the drl-file should be ok, it worked in
the previous drl version. I don't know why it doesn't work anymore.
Regards
Thomas
*
18 years, 1 month
Accessing Hashmap values and keys in LHS
by thomas kukofka
Hello,
I have a Hashmap<String, Double> hm as Input and want to execute the rule
for each key respectively value.
when
hm: HashMap()
value: Number() from hm.values()
key: String() from hm.keySet()
then ...
But unfortunately it doesn't work like this. Any ideas?
Regards
Thomas
18 years, 1 month
Measuring Drools Memory Usage
by Roger Tanuatmadja
Hi,
Has anyone attempted to measure the incremental memory usage of using
Drools? Anyone cares to share their methodology?
I am currently following the following methodology:
1. Prevent garbage collection from happening by using large Xms Xmx (1024m
in my case), a NewRatio of 2 (I am sure other sizes will work as well) and
verbogegc enabled to confirm that no garbage collection is happening.
2. Use Runtime.freeMemory before and after fireAllRules and measuring the
difference.
The problem with my methods so far has been that after a positive memory
usage (indicating you are using memory), subsequent use case (the same one)
incurs zero memory usage which is very strange.
So I guess my question is 2 fold: anyone care to share their methodology,
and can anyone see what's wrong with mine?
Thanks,
Roger
18 years, 1 month
enums
by thomas kukofka
Hi,
I tried this. No problem at all.
I can use enums also like this:
io: InputObject(type == InputObject.Parameter.PARAMETERNAME)
Only this causes the error:
private HashMap<Parameter, String> stringParameters;
public HashMap<Parameter, String> getStringParameters() {
return stringParameters;
}
public void setStringParameters(HashMap<Parameter, String> stringParameters) {
this.stringParameters = stringParameters;
}
*
io: InputObject (
stringParameters[InputObject.Parameter.ParameterName] ==*
*"something") -**> Field/method 'InputObject' not found for class
'com.rules.InputObject'Rule
*>* Compilation error**
*
If I use String instead of Parameter it works again:
private HashMap<String, String> stringParameters;
* io: InputObject ( stringParameters["somestring"] ==* *"something") *
Thomas
*Scott Reed*
sreed at avacoda.com
<rules-users%40lists.jboss.org?Subject=%5Brules-users%5D%20enums&In-Reply-...>
*Mon Jul 28 09:10:48 EDT 2008*
Try a simple rule that just checks for any InputObject to make sure you
have the class imported correctly.
Rule "x"
when
InputObject()
then
end
thomas kukofka wrote:
>* Hello,
*>*
*>* If have an input object Inputobject which contains an enum
Parameter which contains all allowed parameters of InputObject:
*>*
*>*
*>* The entries for the parameters are stored in a map:
*>* private HashMap<Parameter, String> stringParameters;
*>*
*>* If I try:
*>* io: InputObject ( stringParameters[InputObject.Parameter.ParameterName] ==
*>*
*>*
*>* "something")
*>*
*>* I got the error
*>* =>Field/method 'InputObject' not found for class 'com.rules.InputObject'Rule
*>* Compilation error
*>*
*>* Kind Regards
*>* Thomas*
18 years, 1 month
query or global
by thomas kukofka
Hello again,
what are disadvantages and advantages of the following possibillities to to
get access to working memory facts from outside:
- -uses a query:
in drl:
query "queryname"
...
end
in java code
queryResults results = workingMemory.getQueryResults( "queryname" );
- -use globals that store facts:
global java.util.HashMap service
rule "XY"
when
f: FactX ()
then
ResultFact resultFact = new ResultFact();
service.put(f.getName(), resultFact);
insert(resultFact);
end
kind regards
tom
18 years, 1 month
database access via JDBC
by thomas kukofka
Hello,
is it possible to access a database from within the rule file via JDBC?
I only read about access via Hibernate. Is there any JDBC example?
regards
Tom
18 years, 1 month
enums
by thomas kukofka
Hello,
If have an input object Inputobject which contains an enum Parameter
which contains all allowed parameters of InputObject:
The entries for the parameters are stored in a map:
private HashMap<Parameter, String> stringParameters;
If I try:
io: InputObject ( stringParameters[InputObject.Parameter.ParameterName] ==
"something")
I got the error
=>Field/method 'InputObject' not found for class 'com.rules.InputObject'Rule
Compilation error
Kind Regards
Thomas
18 years, 1 month
