Solved HashMap alternative

Hey, so I have a hashmap to store whether a player has selected an upgrade or not. If so, then the upgrade takes place, if not it doesn't. There is one problem with this, which is that maps get reset on server reload/restart, which I want to prevent. Is there any way to keep it stored after the reload or any other alternative? I acknowledge the fact that I could somehow store this in a config, however that would be insufficient and possibly laggy. I was wondering if you could save the map values on disable and they would still be valid?

 

OnDisable save the hashmap to a file, onEnable reload it into a hashmap.

 

@SuperOriginal
after reloading it onto the hashmap, remove it from the file again?

 

No. It's not going to cause lag by just sitting there.

 

@ProMCKingz Well in the event of a server crash the hashmap data would be lost so it would be best to have some data in a file.

 

@SuperOriginal

Thanks,