2 Replies Latest reply on Sep 9, 2013 7:49 PM by srikanth mallikarjuna

    NPE Loading Knowledge Base from URL

    M Arnold Newbie

      Hi,

       

      I'm using Drools and Guvnor 5.3.1.  When I try to load my knowledge base from Guvnor like this:

      {code}

         KnowledgeAgentConfiguration kaconf = KnowledgeAgentFactory.newKnowledgeAgentConfiguration();

                   kaconf.setProperty("drools.agent.scanDirectories", "false");

                   kaconf.setProperty("drools.agent.scanResources", "false");

       

                   KnowledgeAgent ka = KnowledgeAgentFactory.newKnowledgeAgent("agent", kaconf);

       

                   URL url = new URL(urlString);

                   UrlResource urlResource = (UrlResource)ResourceFactory.newUrlResource(url);

                   ka.applyChangeSet(urlResource);

                   kbase = ka.getKnowledgeBase();

      {code}

       

      I get this exception:

       

      {code}

      java.lang.NullPointerException

              at org.drools.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:148)

              at org.drools.agent.impl.KnowledgeAgentImpl.addResourcesToKnowledgeBase(KnowledgeAgentImpl.java:1016)

              at org.drools.agent.impl.KnowledgeAgentImpl.rebuildResources(KnowledgeAgentImpl.java:785)

              at org.drools.agent.impl.KnowledgeAgentImpl.buildKnowledgeBase(KnowledgeAgentImpl.java:657)

              at org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentImpl.java:190)

              at org.drools.agent.impl.KnowledgeAgentImpl.applyChangeSet(KnowledgeAgentImpl.java:169)

      [snip]

      {code}

       

      I've tried 'Rebuilding all snapshot binaries'.  Has my repository become corrupted?

       

      Also, can I build my knowledge base directly from Guvnor's JCR implementation, rather than over HTTP?  I'm not interested in listening / scanning for changes to the underlying packages.  I just want to load my rules and processes from Guvnor.

       

      Apologies if this is not the correct forum.  I couldn't find a discussion forum for Drools.

       

      Thanks