form "ISO-8859-1" charset to the ""Cp1251"

I use Oracle 8.1.7 for Windows.
The database created with codepage Cp1251.
I use any client and get a correct result.
I used this Db for the Java project under JServ and everything works fine.
But under Tomcat and Dbforms I've got a trouble.
As I know there are 2 major approach for solving encoding  problem.
1. Put in your control servlet code like this
public void doPost(HttpServletRequest request,HttpServletResponse response)
  throws ServletException, IOException
{
// In the real world we have read charset value from servlet config

request.setCharacterEncoding("Cp1251");

String value = request.getParameter("value");
...
}
2. Use a filter.
   2.1 I've added to the top of the web.xml
     <filter>
         <filter-name>Set Character Encoding</filter-name>
         <filter-class>filters.SetCharacterEncodingFilter</filter-class>
         <init-param>
             <param-name>encoding</param-name>
             <param-value>UTF-8</param-value>
         </init-param>
   </filter>
    <filter-mapping>
         <filter-name>Set Character Encoding</filter-name>
         <url-pattern>/*</url-pattern>
     </filter-mapping>
   2.2 Then I've added to the ..\WEB-INF\classes\filters
       a filter class.
   2.3 Unfortunately when I've restarted my Tomcat the application
   doesn't work. I got a error about parsing web.xml.
   2.4 For my simple test servlet this way works fine.
   I prefer the second way but this approach doesn't work in my
   example.
   Why ?