Exception handling of KnowledgeBuilder .add for ruleflows should report compilation errors, not null-pointer exception ---------------------------------------------------------------------------------------------------------------------- Key: JBRULES-2545 URL: https://jira.jboss.org/browse/JBRULES-2545 Project: Drools Issue Type: Support Patch Security Level: Public (Everyone can see) Components: drools-compiler Affects Versions: 5.1.0.M2 Environment: Windows XP, Eclipse plugin Reporter: David Goldstein Assignee: Mark Proctor Compiling and adding a ruleflow via KnowledgeBuilder's add method often returns a simple null-pointer exception when information about the actual node that did not compile is available. While one can make a work-around using:             try {                 kbuilder.add(workFlow, workFlowtype);             } catch(Exception t){                 KnowledgeBuilderErrors errors = kbuilder.getErrors();                if (errors.size() > 0)                   for (KnowledgeBuilderError error: errors)                       System.err.println(error);                   }               }                   throw new IllegalArgumentException("Could not parse knowledge.");             } ...       } throwing an exception with the actual build problem in the message seems appropriate so that users see an error describing the build problem when using traditional exception handling: try { kbuilder.add(workFlow, workFlowtype); } catch (Exception t) { t.printStackTrace() } -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira