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<p class=MsoNormal><span lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Thanks Wolfgang! Very helpful!<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal><b><span style='font-size:10.0pt'>发件人<span lang=EN-US>:</span></span></b><span
lang=EN-US style='font-size:10.0pt'> rules-users-bounces@lists.jboss.org
[mailto:rules-users-bounces@lists.jboss.org] </span><b><span style='font-size:
10.0pt'>代表 </span></b><span lang=EN-US style='font-size:10.0pt'>Wolfgang Laun<br>
</span><b><span style='font-size:10.0pt'>发送时间<span lang=EN-US>:</span></span></b><span
lang=EN-US style='font-size:10.0pt'> 2012</span><span style='font-size:10.0pt'>年<span
lang=EN-US>3</span>月<span lang=EN-US>11</span>日<span lang=EN-US> 2:58<br>
</span><b>收件人<span lang=EN-US>:</span></b><span lang=EN-US> Rules Users List<br>
</span><b>主题<span lang=EN-US>:</span></b><span lang=EN-US> Re: [rules-users] </span>答复<span
lang=EN-US>: Adhoc NullPointer exception in rule execution<o:p></o:p></span></span></p>
</div>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Since you ask me... It may not be
"wisdom", though...<o:p></o:p></span></p>
<div>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
</div>
<div>
<p class=MsoNormal><span lang=EN-US>I do not use 'dialect "mvel"' in
the rules I write. Here are some facts on which this decision is based.<o:p></o:p></span></p>
<div>
<ul type=disc>
<li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;
mso-list:l0 level1 lfo1'><span lang=EN-US>My company develops
safety-relevant SW according to the standards set forth by a body called <a
href="http://en.wikipedia.org/wiki/European_Committee_for_Electrotechnical_Standardization">CENELEC</a>.
The (for us) essential standard refutes the use of any language that
hasn't a formal definition. I've never found such a definition for MVEL.<o:p></o:p></span></li>
<li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;
mso-list:l0 level1 lfo1'><span lang=EN-US>A considerable number of Drools
bugs are, in fact, MVEL bugs.<o:p></o:p></span></li>
<li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;
mso-list:l0 level1 lfo1'><span lang=EN-US>Bug fixing of MVEL by its author
is tardy (as I've been told by members of the Drools team), and therefore:<o:p></o:p></span></li>
<li class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;
mso-list:l0 level1 lfo1'><span lang=EN-US>The Drools project had to adopt
the strategy of issuing their own release of MVEL, to be bundled with
Drools releases.<o:p></o:p></span></li>
</ul>
</div>
<div>
<p class=MsoNormal><span lang=EN-US>There's some good reasons why MVEL has been
introduced into Drools, and why it is used when and where it is used. But I
wouldn't recommend it's use in RHS of rules just to save me the trouble of
writing the more verbose Java equivalent.<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
</div>
<div>
<p class=MsoNormal><span lang=EN-US>Also, I'd like to point out that MVEL bug
fixing has picked up as soon as Drools team members were available to do
so. <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
</div>
<div>
<p class=MsoNormal><span lang=EN-US>Cheers<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span lang=EN-US>Wolfgang<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US><o:p> </o:p></span></p>
<div>
<p class=MsoNormal><span lang=EN-US>2012/3/10 Zhuo Li <<a
href="mailto:milanello1998@gmail.com">milanello1998@gmail.com</a>><o:p></o:p></span></p>
<div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Yep, Wolfgang,</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'>It’s a code issue – I just identified it… thanks. I have another
thread talking about NoClassDefFound exception. Would appreciate if you can
share your wisdom there.</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Best</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Abe</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:10.5pt;font-family:"Calibri","sans-serif";
color:#1F497D'> </span><span lang=EN-US><o:p></o:p></span></p>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span
style='font-size:10.0pt'>发件人<span lang=EN-US>:</span></span></b><span
lang=EN-US style='font-size:10.0pt'> <a
href="mailto:rules-users-bounces@lists.jboss.org" target="_blank">rules-users-bounces@lists.jboss.org</a>
[mailto:<a href="mailto:rules-users-bounces@lists.jboss.org" target="_blank">rules-users-bounces@lists.jboss.org</a>]
</span><b><span style='font-size:10.0pt'>代表 </span></b><span lang=EN-US
style='font-size:10.0pt'>Wolfgang Laun<br>
</span><b><span style='font-size:10.0pt'>发送时间<span lang=EN-US>:</span></span></b><span
lang=EN-US style='font-size:10.0pt'> 2012</span><span style='font-size:10.0pt'>年<span
lang=EN-US>3</span>月<span lang=EN-US>11</span>日<span lang=EN-US> 1:06<br>
</span><b>收件人<span lang=EN-US>:</span></b><span lang=EN-US> Rules Users List<br>
</span><b>主题<span lang=EN-US>:</span></b><span lang=EN-US> Re: [rules-users]
Adhoc NullPointer exception in rule execution</span></span><span lang=EN-US><o:p></o:p></span></p>
</div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US> <o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US>The location of the NPE is <o:p></o:p></span></p>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US> at com.xxx.xxx.xxx.xxx.xxx.xxx.xxx(xxx.java:634)<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US>and that's your code, invoked from the right hand side of rule
Match.<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US> <o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US>-W<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US> <o:p></o:p></span></p>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US>2012/3/10 Zhuo Li <<a href="mailto:milanello1998@gmail.com"
target="_blank">milanello1998@gmail.com</a>><o:p></o:p></span></p>
<div>
<div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US>Hi, folks,<o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US> <o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US>I</span>’<span lang=EN-US>m using Drools 5.1, MVEL dialect, JDK 1.6
to build a OLTP system running on tomcat 6.0.28. the runtime environment is on
a cloud virtual and node profile is relatively small. We</span>’<span
lang=EN-US>ve noticed below run time exceptions from prod since it</span>’<span
lang=EN-US>s online from day one which is impacting transaction processing.
However it is happening adhoc-ly. Here I have 1 question:<o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US> <o:p></o:p></span></p>
<p style='margin-left:18.0pt'><span lang=EN-US>1.</span><span lang=EN-US
style='font-size:7.0pt'> </span><span
lang=EN-US>The yellow marked lines are actually java file compiled from DRL
file. Why there is null pointer exception thrown from </span><span lang=EN-US
style='font-size:11.0pt'>org.drools.common.DefaultAgenda.fireActivation?</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US> <o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>ERROR>2012-02-25 11:42:25,071
com.xxx.xxx.xxx.xxx[DefaultQuartzScheduler_Worker-3]: Rules run time error:</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>org.drools.runtime.rule.ConsequenceException:
rule: Match</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'> </span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at
org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:916)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:845)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1056)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at
org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:733)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at
org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:699)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at
org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:218)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at com. xxx.xxx.xxx.xxx.xxx.xxx.xxx (SessionManager.java:94)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at com. xxx.xxx.xxx.xxx.xxx.xxx.yyy(SessionManagerJob.java:17)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at
org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>Caused by: java.lang.NullPointerException</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at com.xxx.xxx.xxx.xxx.xxx.xxx.xxx(xxx.java:634)</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at com.xxx.xxx.xxx.xxx.xxx.yyy.yyy(yyy.java:227)</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at com.xxx.xxx.xxx.xxx.xxx.yyy.zzz(zzz.java:115)</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at com.xxx.xxx.xxx.xxx.xxx.yyy.ttt(ttt.java:83)</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at com.xxx.xxx.xxx.xxx.xxx.yyy.uuu(uuu.java:75)</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'> <span
style='background:yellow'>at com. com.xxx.xxx.xxx.xxx.xxx.yyy.vvv(vvv.java:9)</span></span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt;background:yellow'>
at com. com.xxx.xxx.xxx.xxx.xxx.yyy.www(www.java:28)</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:906)</span><span
lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US style='font-size:11.0pt'>
... 9 more</span><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US>Best regards<o:p></o:p></span></p>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US>Abe<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal style='mso-margin-top-alt:auto;margin-bottom:12.0pt'><span
lang=EN-US><br>
_______________________________________________<br>
rules-users mailing list<br>
<a href="mailto:rules-users@lists.jboss.org" target="_blank">rules-users@lists.jboss.org</a><br>
<a href="https://lists.jboss.org/mailman/listinfo/rules-users" target="_blank">https://lists.jboss.org/mailman/listinfo/rules-users</a><o:p></o:p></span></p>
</div>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span
lang=EN-US> <o:p></o:p></span></p>
</div>
</div>
</div>
<p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US><br>
_______________________________________________<br>
rules-users mailing list<br>
<a href="mailto:rules-users@lists.jboss.org">rules-users@lists.jboss.org</a><br>
<a href="https://lists.jboss.org/mailman/listinfo/rules-users" target="_blank">https://lists.jboss.org/mailman/listinfo/rules-users</a><o:p></o:p></span></p>
</div>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
</div>
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