There’s a new lmdb branch in the LWJGL 3 repository that implements bindings to LMDB. It’s an embedded key-value store that may be used for all kinds of persistence, from game settings to shaders, models and textures (binary values up to Integer.MAX_VALUE in size are supported).
The nightly builds do not include LMDB yet, you’ll have to clone LWJGL and build locally to give it a try. I’ll decide what to do after the 3.0.0 release, but it’s definitely small enough to embed in the standard LWJGL distribution. Please let me know if you’re interested.