Hi guys,


My apologies if I have sent this to the wrong mailing-list (again)! 


I'm very new to Guvnor and Drools and all these exciting tools.  I'm working my way through the example that I found here:




and everything was just fine and dandy until I had to run the java code!

Unfortunately, I get the following output:


RuleAgent(default) INFO (Tue Feb 24 17:20:57 GMT 2009): Configuring with newInstance=false, secondsToRefresh=-1

RuleAgent(default) INFO (Tue Feb 24 17:20:57 GMT 2009): Configuring package provider : URLScanner monitoring URLs:


RuleAgent(default) EXCEPTION (Tue Feb 24 17:20:58 GMT 2009): null. Stack trace should follow.


      at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1340)

      at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)

      at org.drools.agent.HttpClientImpl.fetchPackage(HttpClientImpl.java:59)

      at org.drools.agent.URLScanner.readPackage(URLScanner.java:138)

      at org.drools.agent.URLScanner.getChangeSet(URLScanner.java:110)

      at org.drools.agent.URLScanner.loadPackageChanges(URLScanner.java:88)

      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:148)

      at org.drools.agent.RuleAgent.newRuleAgent(RuleAgent.java:216)

      at com.ioko.GuvnorTest.main(GuvnorTest.java:27)



I’ve had a dig around the source and can see that the problem occurs at the point the package is being read.  This makes me wonder if the package I generated from Guvnor is not correct in some way.  If I point a browser at the url, I get the ‘opening file’ dialog from the browser, asking me to save the file.


I’m really lost right now.  It seems that Guvnor is a pretty good product and would be a good fit.


Can any of you guys please please please help a newbie?


Many thanks,

Adrian M Bell



Adrian M Bell


(+44 (0)1904 438 000

È +44 (0)7515 580652



No.1 Technical Agency, NMA Top 100 Interactive Agencies, 2008

Sunday Times Tech Track 100, 2008



Digital Vision.  Delivered.