Tested and doesn't work, still drops the blacklisted item, you try to check on the entire list, not on an item in the list

!blacklist.contains(getInventory().getItemInSlot(i).getName())

Don't use that code. At no point is the Item defined, so he's having to constantly retrieve a single item from the Inventory class multiple times. This is very inefficient. The parameters are also a limitation too. There may be other conditions you wish to set before dropping anything. I'd go for something like this:

	// From int[] to Integer[] because Arrays.asList(Object) doesn't work with primitive type arrays
	public static final Integer[] VERTICAL_DROP = { 0, 4, 8, 12, 16, 20, 24, 1, 5, 9, 13, 17, 21, 25, 2, 6, 10, 14, 18, 22,
			3, 7, 11, 15, 19, 23 };
	
	public static final List<Integer> VERTICAL_DROP_AS_LIST = Arrays.asList(VERTICAL_DROP);
	
	public void dropAll(Predicate<Item> filter) {
		
		VERTICAL_DROP_AS_LIST.forEach((index) -> {
			
			// Acquire item once, store it as a variable
			Item item = getInventory().getItemInSlot(index);
			
			// Validate the item before interacting with it, also only use filter if one exists
			if (item != null && item.hasAction("Drop") && (filter != null && filter.test(item))) {

				item.interact("Drop");
				
				/*
				 * Item#interact(String...) returns a boolean, which you could
				 * wrap in a selector (IF) for better handling
				 */
			}
		});
	}
	
	public void dropFish() {
		
		// Lambda this shit the fuck up!
		dropAll((item) -> item.getName().equals("Trout") && !item.isNote());
		
	}
	

I haven't actually tested this, but it should work.

 

If you want to go full autist you could have the Integer array explicitly defined within the parameters of the Arrays#asList(Object) method. This would just mean you wouldn't need to define VERTICAL_DROP as a global constant. It's justified too, since VERTICAL_DROP is only ever likely to be referenced once. However having VERTICAL_DROP as mostly dead code isn't going to rip holes in time and space.

VERTICAL_DROP's type needed to be an array of Integer objects and not the primitive type why? They are just indexes. Why did you need to make it into an array list also?

 

dropAll should return a boolean, that is outside of the for loop. Maybe something like use a counter and ++ it every loop iteration, then return Inventory.getCount == 28 - counter. I assume that would work, never tried it though.

I don't understand why this is a snippet? It's just a normal dropping method.