[rules-users] Re: NPE when using directory scanner and drl is incorrect. Possible bug! (Drools 4.0.7)

[Przemysław Różycki]

Small correction.
I've just found this:

https://jira.jboss.org/jira/browse/JBRULES-1436

but it is has to be fixed in 4.0.5 and I'm still experiencing it in 4.0.7.

Best regards,
Przemysław Różycki

Przemysław Różycki pisze:
> Hi,
> 
> I think I found a bug.
> When I use rule agent with directory scanner, and the rule that is being 
> scanned contains a bug, then I receive a NPE instead of error message:
> 
> java.lang.NullPointerException
> 
> 
>         at org.drools.agent.FileScanner.readPackage(FileScanner.java:102)
> 
> 
>         at org.drools.agent.FileScanner.getChangeSet(FileScanner.java:79)
> 
> 
>         at 
> org.drools.agent.FileScanner.loadPackageChanges(FileScanner.java:57)
> 
> 
>         at 
> org.drools.agent.DirectoryScanner.loadPackageChanges(DirectoryScanner.java:43) 
> 
> 
> 
>         at org.drools.agent.RuleAgent.checkForChanges(RuleAgent.java:330)
> 
> 
>         at org.drools.agent.RuleAgent.refreshRuleBase(RuleAgent.java:298)
> 
> 
>         at org.drools.agent.RuleAgent.configure(RuleAgent.java:284)
> 
> 
>         at org.drools.agent.RuleAgent.init(RuleAgent.java:208)
> 
> 
>         at org.drools.agent.RuleAgent.newRuleAgent(RuleAgent.java:176)
> 
> 
>         at org.drools.agent.RuleAgent.newRuleAgent(RuleAgent.java:164)
> ... (further entries of stack trace contains my application's lines)
> 
> When I looked into code I found that DirectoryScanner object, used by 
> the agent uses FileScanner object to scan each file in a directory. And 
> the file scanner does not have a listener set. That's why the NPE is 
> thrown.
> It's difficult to find a bug in the rule.
> I didn't find it in JIRA. If anyone knows, that it was reported, then I 
> won't duplicate, otherwise, I think it is worth to create a report.
> 
> Best regards,