Re: [rules-users] counting facts of a kind

You've probably configured your system to be using persistence? In which case what you are persisting needs to be serializable so that it can be persisted Thomas From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Wolfgang Laun Sent: 23 August 2010 12:17 To: Rules Users List Subject: [rules-users] counting facts of a kind As simple as it gets: rule countHigh when $n : Number() from accumulate ( $sgc : StartGoalConn() count( $sgc ) ) then System.out.println( "plain routes: " + $n ); end And yet, it fails: Exception in thread "main" org.drools.RuntimeDroolsException: java.lang.ClassCastException: rss.ixl.route.TrainStartGoalConn cannot be cast to java.io.Serializable Sure, adding "implements Serializable" to StartGoalConn fixes this. But why is this necessary? FYI, StartGoalConn is abstract superclass of TrainStartGoalConn - just in case this has some bearing on this issue. Best -W ________________________________ ************************************************************************************** This message is confidential and intended only for the addressee. If you have received this message in error, please immediately notify the postmaster(a)nds.com and delete it from your system as well as any copies. The content of e-mails as well as traffic data may be monitored by NDS for employment and security purposes. To protect the environment please do not print this e-mail unless necessary. NDS Limited. Registered Office: One London Road, Staines, Middlesex, TW18 4EX, United Kingdom. A company registered in England and Wales. Registered no. 3080780. VAT no. GB 603 8808 40-00 **************************************************************************************