I've been working on my first open source java library and few days ago I finished it! It took me around 3 weeks to make it.
It's a library that makes it easy to access Spotify's Web API and fetch all sorts of data within minutes.
You can find the library here
I've also tried to write some documentation to explain how to use this library.
Please check it out. I'm a third year university student, so I'm still learning, so any feedback is welcome!