code: @Override
      public void service(ServletRequest req, ServletResponse res)
                      throws ServletException, IOException {
  
          HttpServletRequest request;
          HttpServletResponse response;
  
          try {
              request = (HttpServletRequest) req;
              if (collaborator != null) {
                  ComponentMetaData componentMetaData = ComponentMetaDataAccessorImpl.getComponentMetaDataAccessor().getComponentMetaData();
                  request = new JaxWsHttpServletRequestAdapter(request, collaborator, componentMetaData);
              }
              response = (HttpServletResponse) res;
          } catch (ClassCastException e) {
              throw new ServletException("Unrecognized HTTP request or response object", e);
          }
  
          String method = request.getMethod();
          if (KNOWN_HTTP_VERBS.contains(method)) {
              super.service(request, response);
          } else {
              handleRequest(request, response);
          }
      }
docs: As AbstractHTTPServlet in CXF, with this, it will make sure that, all the request methods
  will be routed to handleRequest method.