jsp 二级域名共享session

 protected void configureSessionCookie(Cookie cookie) {
         cookie.setMaxAge(-1);
         String contextPath = null;
         if (!connector.getEmptySessionPath() && (getContext() != null)) {
             contextPath = getContext().getEncodedPath();
         }
         if ((contextPath != null) && (contextPath.length() > 0)) {
             cookie.setPath(contextPath);
         } else {
             cookie.setPath("/");
         }

         <span style="color: #ff0000;">cookie.setDomain("xxx.com");</span>

         if (isSecure()) {
             cookie.setSecure(true);
         }
     }

 ...