WebMehod that return List

@WebMethod(operationName = "affTable")
    public List affTable(@WebParam(name = "nameT") String nameT, @WebParam(name = "nameBDD") String nameBDD) throws IOException
    {
        try
        {
            Class.forName( "com.mysql.jdbc.Driver" );
            conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/"+nameBDD,"root","");
            pst=conn.createStatement();
            rs=pst.executeQuery("select *  from "+nameT);
            Tab = net.proteanit.sql.DbUtils.resultSetToNestedList(rs);      
        }
        catch(Exception e)
        {
            System.out.println(" Echec !");
            e.printStackTrace();
        }
    return Tab;
    }