Taking 1 item from ItemStack and placing 64 on cursor

What I need to do is when you right-click an item it will take 1 away and give you 64 of another item on the cursor.
This is what I currently have:

Code:

@EventHandler
    public void decompress(InventoryClickEvent e) {
        if (e.getAction().equals(InventoryAction.PICKUP_HALF)) {
            ItemStack item = e.getCurrentItem();
            Integer amount = item.getAmount();
            if (item.getType().equals(Material.GOLD_INGOT)) {
                e.setCancelled(true);
                if(amount > 1) {
                    item.setAmount(amount-1);

                } else {
                    item = null;
                }
            }
        }
    }

But I don't know if I should use e.getCurrentItem() and take 1 away from it since I cancel the event. And if that is what I'm supposed to do then what do I use to set an item on the cursor afterwards?

 

@martijnpold
So, I take one item, then it takes 64 of that item?

 

No, I want to take 1 from the item i clicked and then add 64 of another item to the cursor.

 

@martijnpold
player#setItemInHand();

EDIT: player#setItemInCursor();