This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Are you using weblogic for deployment ? In that case, weblogic has their own proprietary wrapper classes for result set, blob etc. It will not return oracle.jdbc.driver.OracleResultSet, but would return weblogic.jdbc.vendor.oracle.OracleResultSet. Similarly other App servers might have their own implementation classes.