How ADF client authentication can be defined or set in the web.xml

<security-constraint>

<web-resource-collection>
<web-resource-name>allPages</web-resource-name>
<url-pattern>/*</url-pattern>
</web-resource-collection>
<auth-constraint>
<role-name>valid-users</role-name>
</auth-constraint>
</security-constraint>
<security-constraint>
<web-resource-collection>
<web-resource-name>adfAuthentication</web-resource-name>
<url-pattern>/adfAuthentication</url-pattern>
</web-resource-collection>
<auth-constraint>
<role-name>valid-users</role-name>
</auth-constraint>
</security-constraint>
<login-config>
<auth-method>CLIENT-CERT</auth-method>
</login-config>
<security-role>
<role-name>valid-users</role-name>
</security-role>