Getting a GUI Menu's Content

hello all,
I have been trying to get a GUI Menu for my ItemSaver Plugin and I'd like to know how to a GUI Menu's content(Inventory => ItemStack[] or something like that ). if anyone could tell me how I would be graceful

 

its um self-explanatory?

Code:Java

Inventory aye;
ItemStack[] realnicecontents = aye.getContents();

 

else you should use
(use clickinventoryevent)
Inventory inv = e.getInventory();
ItemStack = inv.getItem(int);
Inventory ;

 

I tryied it myself but it just returns null ... how to replace null by material.air ?
Edit: I tought about doing a condition :
if it's null return Material.AIR;
else return item

 

(I am trying to use this too) I am trying to make a Crafting recipe from a Menu
but item that are Air cannot be saved in the recipe

 

Just check the recipe and if the slot is null, ignore it, and save the other slots?

If by make a recipe you mean to create a new custom recipe from the GUI.