Most methods in WrappedConnection inherit jdoc from interface. However, checkStatus() does more than check for connection and its state( not closed), it requires transaction to be in certain state. THis does more than jdoc contract state, so methods like getAutoCommit(), getTransactionIsolation etc will throw SQL Exception if transation is not open/no transaction etc, as per: https://github.com/oloake/IronJacamar/blob/master/adapters/src/main/java/org/jboss/jca/adapters/jdbc/WrapperDataSource.java#L237