[rules-users] Drools and Jersey

Wed Mar 14 12:32:13 EDT 2012

Do you mean that the NPE deep inside Jersey only happens when you use
dialect "mvel"?!?

Disaster strikes in MVEL when it tries to report the exception thrown
while the rule executes.

Which Drools version are you using?
-W

On 14/03/2012, mike <mikemps at gmail.com> wrote:
> Wait ... I haven't solved the problem ... I mean, as of now I cannot use
> mvel if I want to use Jersey ... and I don't think it's Jersey's fault
> because it works in any condition except when using mvel. I thought that
> the Drools team follows this list and might be interested in that bug.
>
> Thank you very much
> Mike
>
> 2012/3/14 Mauricio Salatino <salaboy at gmail.com>
>
>> Cool that you find that :)
>> Cheers
>>
>>
>> 2012/3/14 mike <mikemps at gmail.com>
>>
>>> Hi Mauricio,
>>>
>>> I spent like 2 days debugging, before realizing that mvel was the
>>> culprit. The error is a Null Exception when resolving some service inside
>>> Jersey. I have to check my browser history at home for more details but
>>> the
>>> exception was happening inside Jersey.
>>>
>>> Please notice I reduced the code to the minimum. I had 'real' code doing
>>> more reasonable things with new Client. Client c = new Client() fails
>>> too.
>>>
>>> Thank you very much
>>>  Mike
>>>
>>>
>>> 2012/3/14 Mauricio Salatino <salaboy at gmail.com>
>>>
>>>> Hi Mike, I've never tried that before (a rule without the when part..)
>>>> is good to know that it works :)
>>>> Humm that's sounds weird.. why the dialect is affecting your Client
>>>> creation.
>>>> It could be that there is something wrong with the expression
>>>> evaluation.
>>>> It looks like MVEL cannot compile the new Client(); expression -> at
>>>> java.lang.String.<init>(Unknown Source)
>>>> Did you try with something like:
>>>> then \n
>>>> Client c = new Client();
>>>>
>>>> I'm just guessing here, because it looks strange
>>>>
>>>>
>>>> 2012/3/14 mike <mikemps at gmail.com>
>>>>
>>>>> Hi Mauricio,
>>>>>
>>>>> Thank you for the speedy reply. Ia m making rest call to web services
>>>>> using jersey. I simplified the rule to the max. The 'when' is not
>>>>> really
>>>>> needed. I get the exception on the call to "new Client()". Please keep
>>>>> in
>>>>> mind it works without dialect "mvel".
>>>>>
>>>>> Thank you very much
>>>>> Mike
>>>>>
>>>>> Here's the stack trace .............
>>>>> java.lang.StringIndexOutOfBoundsException: String index out of range:
>>>>> -1
>>>>> at java.lang.String.<init>(Unknown Source)
>>>>>  at
>>>>> org.mvel2.CompileException.showCodeNearError(CompileException.java:149)
>>>>> at
>>>>> org.mvel2.CompileException.generateErrorMessage(CompileException.java:219)
>>>>>  at org.mvel2.CompileException.toString(CompileException.java:62)
>>>>> at java.lang.Throwable.<init>(Throwable.java:242)
>>>>>  at java.lang.Exception.<init>(Unknown Source)
>>>>> at java.lang.RuntimeException.<init>(Unknown Source)
>>>>>  at
>>>>> org.drools.runtime.rule.ConsequenceException.<init>(ConsequenceException.java:31)
>>>>> at
>>>>> org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)
>>>>>  at
>>>>> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:1101)
>>>>> at
>>>>> org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:1029)
>>>>>  at
>>>>> org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1251)
>>>>> at
>>>>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:709)
>>>>>  at
>>>>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:673)
>>>>> at
>>>>> org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:218)
>>>>>  at
>>>>> com.ultimatesoftware.engine.tests.Wip.drools_new_client(Wip.java:32)
>>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>>>>>  at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
>>>>> at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
>>>>>  at java.lang.reflect.Method.invoke(Unknown Source)
>>>>> at
>>>>> org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
>>>>>  at
>>>>> org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
>>>>> at
>>>>> org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
>>>>>  at
>>>>> org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
>>>>> at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
>>>>>  at
>>>>> org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:69)
>>>>> at
>>>>> org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:48)
>>>>>  at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
>>>>> at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
>>>>>  at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
>>>>> at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
>>>>>  at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
>>>>> at org.junit.runners.ParentRunner.run(ParentRunner.java:292)
>>>>>  at
>>>>> org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
>>>>> at
>>>>> org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
>>>>>  at
>>>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
>>>>> at
>>>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
>>>>>  at
>>>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
>>>>> at
>>>>> org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
>>>>>
>>>>>
>>>>>
>>>>> 2012/3/14 Mauricio Salatino <salaboy at gmail.com>
>>>>>
>>>>>> what are you trying to do?
>>>>>> what's the error?
>>>>>>
>>>>>> the rule should look like
>>>>>>
>>>>>> rule "create Rest Client"
>>>>>>     when
>>>>>>     then new Client();
>>>>>> end
>>>>>>
>>>>>> 2012/3/14 mike <mikemps at gmail.com>
>>>>>>
>>>>>>>  Hi there,
>>>>>>>
>>>>>>> I am trying to make rest calls from Drools. For that I am using
>>>>>>> Jersey http://jersey.java.net/. I cannot no get it to work if I use
>>>>>>> mvel, otherwise it works fine.
>>>>>>>
>>>>>>> Here is a sample rule:
>>>>>>> ----------------------------------------------------------
>>>>>>> import com.sun.jersey.api.client.Client;
>>>>>>>
>>>>>>> dialect  "mvel"
>>>>>>>
>>>>>>> rule "create Rest Client"
>>>>>>>     then new Client();
>>>>>>> end
>>>>>>> ----------------------------------------------------------
>>>>>>>
>>>>>>> I would love to be able to use mvel since it curves java syntax :)
>>>>>>>
>>>>>>> Thank you
>>>>>>> Mike
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> rules-users mailing list
>>>>>>> rules-users at lists.jboss.org
>>>>>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>>  - MyJourney @ http://salaboy.wordpress.com
>>>>>>  - Co-Founder @ http://www.jugargentina.org
>>>>>>  - Co-Founder @ http://www.jbug.com.ar
>>>>>>
>>>>>>  - Salatino "Salaboy" Mauricio -
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> rules-users mailing list
>>>>>> rules-users at lists.jboss.org
>>>>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> rules-users mailing list
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>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>>  - MyJourney @ http://salaboy.wordpress.com
>>>>  - Co-Founder @ http://www.jugargentina.org
>>>>  - Co-Founder @ http://www.jbug.com.ar
>>>>
>>>>  - Salatino "Salaboy" Mauricio -
>>>>
>>>>
>>>> _______________________________________________
>>>> rules-users mailing list
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>>>>
>>>>
>>>
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>>>
>>
>>
>> --
>>  - MyJourney @ http://salaboy.wordpress.com
>>  - Co-Founder @ http://www.jugargentina.org
>>  - Co-Founder @ http://www.jbug.com.ar
>>
>>  - Salatino "Salaboy" Mauricio -
>>
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
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>>
>