[rules-users] NullPointerException when using Drools rule template

[Wolfgang Laun]

If you move the
  template contract_rate
up in front of the first rule "holiday july 4th" the NPE is gone. I
haven't been able to validate the (presumably) generated rule set, but
you should be able to do that now.

Nevertheless, this warrants a JIRA, which I'll create forthwith. Also,
the docs should indicate what is permitted up front, preceding the
"template" statement.

-W


2010/11/10 Roger Smith <rogersmith1711 at gmail.com>:
> Wolfgang,
>
> I have enclosed the template. For debugging purpose, I have removed all but
> one rule.
>
> Thanks,
>
> Roger
>
> - O -
>
> template header
> summerOnPeakPrimaryRate
> summerOnPeakSecondaryRate
> summerSemiPeakPrimaryRate
> summerSemiPeakSecondaryRate
> summerOffPeakPrimaryRate
> summerOffPeakSecondaryRate
> winterOnPeakPrimaryRate
> winterOnPeakSecondaryRate
> winterSemiPeakPrimaryRate
> winterSemiPeakSecondaryRate
> winterOffPeakPrimaryRate
> winterOffPeakSecondaryRate
>
> package tradex.contract.sde
>
> import tradex.process.ruler.server.ContractRule
>
> rule "holiday july 4th"
> when
>   $r : ContractRule( year == 2010 && month == 7 && day == 4 && holiday ==
> false)
> then
>   modify($r){
>     setHoliday(true)
>   }
> end
>
> rule "holiday xmas"
> when
>   $r : ContractRule( year == 2010 && month == 12 && day == 25 && holiday ==
> false)
> then
>   modify($r){
>     setHoliday(true)
>   }
> end
>
> rule "Season summer"
> when
>   $r : ContractRule( dayOfYear >= 121 && dayOfYear <= 273 && season ==
> "undefined")
> then
>   modify($r){
>     setSeason("summer")
>   }
> end
>
> rule "Season winter"
> when
>   $r : ContractRule( (dayOfYear >= 274 || dayOfYear <= 120) && season ==
> "undefined")
> then
>   modify($r){
>     setSeason("winter")
>   }
> end
>
>
> rule "On peak hour"
> when
>   $r : ContractRule( holiday == false && dayOfWeek >= 1 && dayOfWeek <= 6
> && hourOfDay >= 1400 && hourOfDay <= 2000 &&
>   hourType == "undefined")
> then
>   modify($r){
>     setHourType("onPeak")
>   }
>
> end
>
> rule "Semi peak hour"
> when
>   $r : ContractRule( holiday == false && dayOfWeek >= 1 && dayOfWeek <= 6
> && (hourOfDay >= 600 && hourOfDay < 1400 ||
>   hourOfDay > 2000 && hourOfDay <= 2200) && hourType == "undefined")
> then
>   modify($r){
>     setHourType("semiPeak")
>   }
> end
>
> rule "Off peak hour"
> when
>   $r : ContractRule( (holiday == true ||  dayOfWeek == 7  || hourOfDay < 600
> || hourOfDay > 2200) && hourType == "undefined" )
> then
>   modify($r){
>     setHourType("offPeak")
>   }
> end
>
> template contract_rate
>   rule "Summer on peak primary rate"
>   when
>     $r : ContractRule( season == "summer" && hourType == "onPeak" && type ==
> "primary")
>   then
>     $r.setRate(@{summerOnPeakPrimaryRate});
>   end
> end template
>
>
>
>
> 2010/11/9 Wolfgang Laun <wolfgang.laun at gmail.com>
>>
>> Seeing the template .drl would help to resolve this. Are all @{parameter}s
>> declared in the template header?
>> -W
>>
>> 2010/11/9 Roger Smith <rogersmith1711 at gmail.com>
>>>
>>>
>>> All -
>>>
>>> I tried out Drools rule template with a with a proptotype app. Drools is
>>> throwing NullPointerException as below. I would much appreciate if someone
>>> on this list can help.
>>> java.lang.NullPointerException
>>>     at
>>> org.drools.template.parser.DefaultTemplateColumn.createCellCondition(DefaultTemplateColumn.java:68)
>>>     at
>>> org.drools.template.parser.DefaultTemplateColumn.addCondition(DefaultTemplateColumn.java:91)
>>>     at
>>> org.drools.template.parser.DefaultTemplateRuleBase.createColumnConditions(DefaultTemplateRuleBase.java:105)
>>>     at
>>> org.drools.template.parser.DefaultTemplateRuleBase.createTemplateRule(DefaultTemplateRuleBase.java:98)
>>>     at
>>> org.drools.template.parser.DefaultTemplateRuleBase.getDTRules(DefaultTemplateRuleBase.java:85)
>>>     at
>>> org.drools.template.parser.DefaultTemplateRuleBase.<init>(DefaultTemplateRuleBase.java:64)
>>>     at
>>> org.drools.template.parser.TemplateDataListener.<init>(TemplateDataListener.java:76)
>>>     at
>>> org.drools.template.parser.TemplateDataListener.<init>(TemplateDataListener.java:52)
>>>     at
>>> org.drools.template.ObjectDataCompiler.compile(ObjectDataCompiler.java:44)
>>>
>>>
>>> Here is my code
>>>
>>>         KnowledgeBuilder kBuilder =
>>> KnowledgeBuilderFactory.newKnowledgeBuilder();
>>>         ObjectDataCompiler converter = new ObjectDataCompiler();
>>>         InputStream dis = new FileInputStream( new File(
>>> "/home/pranab/Projects/gridx/ct11_1.drl" ) );
>>>         if (null == dis){
>>>           System.out.println("null rule template stream");
>>>           return;
>>>         }
>>>
>>>         Collection<Map<String,Object>> paramMaps = new
>>> ArrayList<Map<String,Object>>();
>>>
>>>         Map<String,Object> params = new HashMap<String,Object>();
>>>
>>>         params.put("summerOnPeakPrimaryRate", new Integer(299));
>>>         params.put("summerOnPeakSecondaryRate", new Integer(524));
>>>         params.put("summerSemiPeakPrimaryRate", new Integer(176));
>>>         params.put("summerSemiPeakSecondaryRate", new Integer(305));
>>>         params.put("summerOffPeakPrimaryRate", new Integer(139));
>>>         params.put("summerOffPeakSecondaryRate", new Integer(243));
>>>         params.put("winterOnPeakPrimaryRate", new Integer(249));
>>>         params.put("winterOnPeakSecondaryRate", new Integer(438));
>>>         params.put("winterSemiPeakPrimaryRate", new Integer(176));
>>>         params.put("winterSemiPeakSecondaryRate", new Integer(305));
>>>         params.put("winterOffPeakPrimaryRate", new Integer(139));
>>>         params.put("winterOffPeakSecondaryRate", new Integer(243));
>>>         paramMaps.add(params);
>>>
>>>         String drl = converter.compile(paramMaps, dis);
>>>         Reader rdr = new StringReader( drl );
>>>         kBuilder.add( ResourceFactory.newReaderResource(rdr),
>>> ResourceType.DRL);
>>>
>>>
>>> The line in blue is throwing the exception. This code is very similar to
>>> the example code in Drools Expert guide.
>>>
>>> Best,
>>>
>>> Roger
>>>
>>> _______________________________________________
>>> rules-users mailing list
>>> rules-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>
>>
>>
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