What is a tutorial covering Java app. BASIC authentication on a tomcat 7 web server? How to secure a java servlet running on the tomcat web server? What is the web.xml login-config tag? What is the web.xml security-constraint tag? How to secure a urt pattern in a java web application? What is the web.xml auth-constraint tag? What is the tomcat-users.xml file? How to add a users and roles on a tomcat web server?