tomcat 二级域名 共享session 的方法

lue: "                              + value.toString());                      containerLog.debug("CrossSubdomainSessionValve:  new Set-Cookie value: " + buffer);                      value.setString(buffer.toString());                  }              }          }      }        /** Returns the last two parts of the specified request's server name preceded by a dot.      * Using this as the session cookie's domain allows the session to be shared across subdomains.      * Note that this implies the session can only be used with domains consisting of two or      * three parts, according to the domain-matching rules specified in RFC 2109 and RFC 2965.      *      * <p>Examples:</p>      * <ul>      * <li>foo.com => .foo.com</li>      * <li>www.foo.com => .foo.com</li>      * <li>bar.foo.com => .foo.com</li>      * <li>abc.bar.foo.com => .foo.com - this means cookie won't work on abc.bar.foo.com!</li>      * </ul>      *      * @param request provides the server name used to create cookie domain.      * @return the last two parts of the specified request's server name preceded by a dot.      */      protected String getCookieDomain(Request request)      {          String cookieDomain = request.getServerName();          String[] parts = cookieDomain.split("\.");          if (parts.length >= 2)              cookieDomain = parts[parts.length - 2] + "." +  parts[parts.length - 1];          return "." + cookieDomain;      }        public String toString()      {          return ("CrossSubdomainSessionValve[container=" +  container.getName() + ']');      }  }