local itemStack = import("org.bukkit.inventory.ItemStack")
local material = import("$.Material")
local title = "This is the inventory title"
local inv = plugin.getServer():createInventory(nil, slots, title)
local newItemStack = luajava.new(itemStack, material.GRASS, countOfItems, 0)
inv:setItem(setSlot, newItemStack)
-- Open inventory for player
player:openInventory(inv)