Unable to resolve superclass error when referencing .jar library
Just started to get this issue after upgrading to ADT 17.
Discovered that external .jar files need to be in a 'libs' (with an s) folder otherwise their classes are not included in the .dex file that is created. Before the upgrade everything worked fine with my .jar files in a 'lib' folder (no s).
In my case I had to go to Properties->Java Build Path->Order and Export and check Android Private Libraries, then cleaned the project and worked fine.
Create lib folder, libs folder is for native libraries. I made it, add library to lib and to build path as internal library and it works!