code: public void handle(String pathInContext,
                         String pathParams,
                         HttpRequest request,
                         HttpResponse response)
              throws HttpException,IOException
      {
          log.debug("ExpiryHandler.handle()");
          String expires;
          if (_ttl<0)
              expires=HttpFields.__01Jan1970;
          else
              expires=HttpFields.formatDate
                (System.currentTimeMillis()+1000L*_ttl,false);
          response.setField(HttpFields.__Expires,expires);
      }
docs: Handle a request by pre-populating the Expires header with a a value
  that corresponds to now + ttl. If ttl -s negative then
  HttpFields.__01Jan1970 is used.
  
  Settings made here can be overridden by subsequent handling of the
  request.
  
  @param pathInContext The context path
  @param pathParams Path parameters such as encoded Session ID
  @param request The HttpRequest request
  @param response The HttpResponse response