As my plans with 1.3 did not work as expected and had many issues I couldn't fix at that Time, I decided to code something different.
+ Added 2 new Methods and 1 Class.
~ All old methods are deprecated and will be removed in the next version (2.1)
I have created a Class (PD) for the purpose to have every String/Integer and Boolean saved, relevant to that Player.
Two Methods (loadPlayers and savePlayers) will be used to load and save the data.
loadPlayers loads a java.util.List<PD> containing all saved players of that specific Plugin (or an empty List<PD> if there was no file).
savePlayers saves a java.util.List<PD> to the saveFile and creates a backup of the old one.
The PlayerData class (PD) contains a Map for each String, Integer and Boolean and the UUID of the Player.
I also cleaned up the Javadocs, they should have now links to each used type and should only contains the important classes, which you have access to.
There will be an example in the Overview.
I hope you'll like the new version.