In my Android app, each activity is filled with data from an xml file which is somewhere on the web. The website providing these files has a login mechanism, that works with
LoopJ has a built in persistent cookie store that can be used with or without the loopj framework
https://github.com/loopj/android-async-http/blob/master/library/src/main/java/com/loopj/android/http/PersistentCookieStore.java