code: private void updateAttributes(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
     {
        String name = request.getParameter("name");
  
        if (trace)
           log.trace("updateAttributes, name=" + name);
  
        Enumeration paramNames = request.getParameterNames();
        HashMap<String, String> attributes = new HashMap<String, String>();
  
        while (paramNames.hasMoreElements())
        {
           String param = (String)paramNames.nextElement();
  
           if (param.equals("name") || param.equals("action"))
              continue;
  
           String value = request.getParameter(param);
  
           if (trace)
              log.trace("name=" + param + ", value='" + value + "'");
  
           // Ignore null values, these are empty write-only fields
           if (value == null || value.length() == 0)
              continue;
  
           attributes.put(param, value);
        }
  
        try
        {
           AttributeList newAttributes = setAttributes(name, attributes);
           MBeanData data = getMBeanData(name);
           request.setAttribute("mbeanData", data);
  
           RequestDispatcher rd = this.getServletContext().getRequestDispatcher("/inspectmbean.jsp");
           rd.forward(request, response);
        }
        catch (Exception e)
        {
           throw new ServletException("Failed to update attributes", e);
        }
     }
docs: Update the writable attributes of a MBean
  @param request The HTTP request
  @param response The HTTP response
  @exception ServletException Thrown if an error occurs
  @exception IOException Thrown if an I/O error occurs