RowSet & Oracle(ojdbc6.jar)

The below result of a test today with ojdbc6.jar in oracle database.
     Connection con =null;
      Statement stmt=null;
      Connection  con =
             DriverManager.getConnection( “jdbc:oracle:thin:@127.0.0.1:1521:test”, User,PW);
            stmt = con.createStatement();
            ResultSet rs = stmt.executeQuery("select * from table1");
          // 1 CachedRowSet is ok.
          CachedRowSet rowSet;
          rowSet=new CachedRowSetImpl();
          rowSet.populate(rs); // It work  
         //2 JdbcRowSet is not ok. Don't know why?
//          JdbcRowSet  rowSet = new JdbcRowSetImpl(rs); // It doesn't work
          rs.close();
          stmt.close();
          con.close();