This ADF training from https://www.fireboxtraining.com/oracle-adf-training demonstrates how to create an ADF login page using a managed bean to capture the user's credentials. It then calls the adfAuthentication servlet to perform the ADF authentication. Part 2 of this tutorial shows you how to set up the authorization to allows specific users to view the page.
Discover more about ADF training courses for business at: https://www.fireboxtraining.com/