WARN [org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker] Unexpected error in pingDatabase: java.lang.IllegalArgumentException: object is not an instance of declaring class {SOLVED}

When we use Oracle driver in application which is deployed JBossAS, We have to place the Oracle driver jar in server/lib directory. If we keep the jar in our Ear or War file also will get this warning message.

15:56:40,098 WARN  [org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker] Unexpected error in pingDatabase: java.lang.IllegalArgumentException: object is not an instance of declaring class

To solve this, just remove the Oracle lib from your Ear or War.