how can i change struts source??

hi,experts,now i want change the process method in jakarta-struts-1.1/lib/struts.jar/org/apache/struts/action/ActionServlet.class

now i hava down the jakarta-struts-1.1 source and in ActionServlet.java,i add two lines,like this:
    /**
     * Perform the standard request processing for this request, and create
     * the corresponding response.
     *
     * @param request The servlet request we are processing
     * @param response The servlet response we are creating
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet exception is thrown
     */
    protected void process(HttpServletRequest request,
                           HttpServletResponse response)
        throws IOException, ServletException {
          request.setCharacterEncoding("gb2312");  //i added it
         response.setContentType("text/html;charset=gb2312"); //i added it

        RequestUtils.selectModule(request, getServletContext());
        getRequestProcessor(getModuleConfig(request)).process
            (request, response);

    }

but when i add it ,i can not compile it, can any experts help me compile it and send me struts.jar, thanks very much!

mymail:jbasttdi@hotmail.com

thanks very much!