Get Arrow from Stack Fired

I'm using a ProjectileLaunchEvent currently, and what I want to do is get the Arrow, or other entity such as a Snowball, and see what itemstack it came from. How would I accomplish this? I need to do this to make sure it's the one with the right item lore.

I could try cancelling the event then seeing if their inventory contains the item with the certain lore, but when a player shoots a bow, there's no way to calculate how charged the bow was, or is there?

Sorry for being so bleak, but thank you everyone who are going to try to help.

 

There is no direct way to get the ItemStack from the ProjectileLaunchEvent here.
You need to create a workaround:

1) Save the data and type of the projectile somewhere.
2) Cancel the event.
3) Check the inventory of the shooter for the given type of projectile (only if it's a player of course).
4) Get the (first) ItemStack that matches the given projectile type.
5) Remove one from that stack manually => here you know exactly which ItemStack was used.
6) Create a new ProjectileLaunchEvent with the same data as before (same direction and type).

Hope this helps.