I created this Minecraft plugin in about 2 days. Using Java and the Spigot framework, I was able to completely replicate another plugin of the same functionality. Having never used this framework before, it took me a second to get used to it, and the database implementations can use improvement, I am still proud of it being fully functional.
You can see a video of it working below:
Or you can have a look at the source code of this plugin on Github below.
Simple Minecraft Spigot Bookshelf Plugin