tomcat 二级域名 共享session 的方法

ommitted.  You are advised to define this  * valve as early as possible in server.xml to ensure that the response has not already been  * committed when this valve is invoked.</p>  *  * <p>We recommend that you define this valve in server.xml immediately after the Catalina Engine  * as follows:  * <pre>  * <Engine name="Catalina"...>  *     <Valve className="org.three3s.valves.CrossSubdomainSessionValve"/>  * </pre>  * </p>  */  public class CrossSubdomainSessionValve extends ValveBase  {      public CrossSubdomainSessionValve()      {          super();          info = "org.three3s.valves.CrossSubdomainSessionValve/1.0";      }        @Override      public void invoke(Request request, Response response) throws  IOException, ServletException      {          //this will cause Request.doGetSession to create the session  cookie if necessary          request.getSession(true);            //replace any Tomcat-generated session cookies with our own          Cookie[] cookies = response.getCookies();          if (cookies != null)          {              for (int i = 0; i < cookies.length; i++)              {                  Cookie cookie = cookies[i];                  containerLog.debug("CrossSubdomainSessionValve: Cookie  name is " + cookie.getName());                  if (Globals.SESSION_COOKIE_NAME.equals(cookie.getName()))                      replaceCookie(request, response, cookie);              }          }            //process the next valve          getNext().invoke(request, response);      }        /** Replaces the value of the response header used to set the specified cookie to a value      * with the cookie's domain set to the value returned by <code>getCookieDomain(request)</code>      *      * @param request      * @param response      * @param cookie cookie to be replaced.      */      @SuppressWarnings("unchecked&qu