Migrating existing Activities application to Fragments

I've an app written for phones. I'm planning on adding Fragments API so that same app runs 1.6 all the way to 3.2. However, the problem is with extending FragmentsActi开发者_Python百科vity. My activities are extending a common activity which has all the common functions. Moving them into interface and implementing them is a lot of rework.

What is the best way out?

Move the code that was in the base Activity to a base Fragment, then have your Fragments extend that.