servlets - Google App Engine : user login page -

if want require users logged in view page on web site, how achieve this? check user login status @ beginning of doget() in every servlet class , redirect log-in page? once user logs in, redirect original servlet? achieve same thing simple configuration if such thing exists?

add tag web.xml file:

<security-constraint>     <web-resource-collection>         <url-pattern>/*</url-pattern>     </web-resource-collection>     <auth-constraint>         <role-name>*</role-name>     </auth-constraint> </security-constraint> 

this require user authenticated in whatever role (role-name) access servlet (url-pattern)