ShiroFilter does not kick in for urls which do not contain /api* in the path

I am trying to enable Oauth on Zeppelin using shiro - buji-pac4j, Oauth is
working, but shiroFilter works only urls like http://myhomelink/api but not
for http://myhomelink, so i modified /api* to /*, it started working,
basically this is the original code in zeppelinServer.java

if (!StringUtils.isBlank(shiroIniPath))

{ webapp.setInitParameter("shiroConfigLocations", new File(shiroIniPath).toURI().toString()); SecurityUtils.initSecurityManager(shiroIniPath); webapp.addFilter(ShiroFilter.class, "/api/*", EnumSet.allOf(DispatcherType.class)); webapp.addEventListener(new EnvironmentLoaderListener()); }

Shiro URLs is as below
[urls]

1. This section is used for url-based security.
2. You can secure interpreter, configuration and credential information by
   urls. Comment or uncomment the below urls that you want to hide.
3. anon means the access is anonymous.
4. authc means Form based Auth Security
   /api/version = anon
   /callback = callbackFilter
   /api/login/logout = logoutFilter
   /** = formClientSecurityFilter
   /** = oidcSecurityFilter

Request the experts to help me udnerstand how to ensure shiroFilter is
getting applied to all the URLS.
What is the necesssity of keeping it /api* instead of /*

Regs
Srikanth G N