Solved Can't cast short from config after restart

Hello, I've created command that saves material and data to config,
Second command loads that material.
When i save the material and load it it works fine.
But when i save the material, restart server and load it, it returns error:
Caused by: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Short
Saving:

Code:

config.set("warp." + args[0] + ".material", ((Player) sender).getItemInHand().getType().toString());
config.set("warp." + args[0] + ".data", ((Player) sender).getItemInHand().getDurability());
saveConfig();

Loading:

Code:

mat = Material.getMaterial(config.getString("warp." + warp + ".material"));
data = (short) config.get("warp." + warp + ".data");

How can i fix this?

 

@timtower Don't want to save amount and metadata

 

@timtower Please can you explain why its happening only after restart?

 

@timtower No, I was calling it like:
Save
Load: working
Restart
Load: error
Save
Load: working
Same load code

 

@timtower Thanks!