You can use the following link instead as there is only a single Java file for this tutorial.

https://gist.github.com/wfng92/f131ea2d96d0d90338bb496aac97cfdc

However you have to follow the tutorial for instruction on how to install the required jar file.

I no longer has the entire app files as this is an old demo project. Thanks a lot and sorry for any inconvenience caused.