啟動cas server
啟動客戶端，訪問url，org.jasig.cas.client.authentication.AuthenticationFilter.initInternal驗證
cas server已經登陸時的流程
EncryptedCookieValueManager.obtainCookieValue(final Cookie cookie, final HttpServletRequest request) 獲取cookie的值
CookieRetrievingCookieGenerator.retrieveCookieValue(final HttpServletRequest request) 檢索cookie的值
ReflectionUtils.invokeMethod(Method method, @Nullable Object target, @Nullable Object... args)
GenericScope.invoke(MethodInvocation invocation)
