I am sorry for missing information in question. I am using Drools 5.1. I find out the reason just now.
I added Generic on Map on the get method for dataMap and now it works. public Map<String, Data> getDataMap() { return dataMap; } Thank you for replying! -- View this message in context: http://drools.46999.n3.nabble.com/can-not-use-mvel-to-access-object-in-a-map-in-THEN-tp3062652p3090003.html Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users