How would one test for the armor a player is wearing and if say the player was wearing a full set of diamond armor give some effect or buff?

If you have a reference to the player, check their equipment slots. There are four of them.

@SubscribeEvent
	public void onDamage(LivingDamageEvent event) {
		EntityPlayer player;
		List<ItemStack> armor = null;
		
		if(event.getEntity() instanceof EntityPlayer) {
			player = (EntityPlayer) event.getEntity();
			armor = (List<ItemStack>) player.getArmorInventoryList();
		}
		if(!armor.isEmpty()) {
			if(armor.get(0) == new ItemStack(ItemInit.BOOTS_MERTHEW)) {
				if(armor.get(1) == new ItemStack(ItemInit.LEGGINGS_MERTHEW)) {
					if(armor.get(2) == new ItemStack(ItemInit.CHESTPLATE_MERTHEW)) {
						if(armor.get(3) == new ItemStack(ItemInit.HELM_MERTHEW)) {
							event.setAmount(0);
						}
					}
				}
			}
		}
	}

This is what i was trying to do, what am i doing wrong?
if you need the git hub: https://github.com/Merthew/MerthewMod/

wrong code.. srry

@Override
	public void onArmorTick(final World world, final EntityPlayer player, final ItemStack itemStack) {
		List<ItemStack> narmor = new ArrayList<ItemStack>();
		narmor.add(new ItemStack(ItemInit.BOOTS_MERTHEW));
		narmor.add(new ItemStack(ItemInit.LEGGINGS_MERTHEW));
		narmor.add(new ItemStack(ItemInit.CHESTPLATE_MERTHEW));
		narmor.add(new ItemStack(ItemInit.HELM_MERTHEW));
		
		List<ItemStack> armor = (List<ItemStack>) player.getArmorInventoryList();
		
		if(armor.get(0) == narmor.get(3)) {
			if (!player.isPotionActive(potionEffect.getPotion())) { // If the Potion isn't currently active,
				player.addPotionEffect(new PotionEffect(potionEffect)); // Apply a copy of the PotionEffect to the player
			}
		}
	}

 

What if they are wearing only a chestplate? Is the list still 4 items long?

Are the items in the right order?

if(armor.get(0) == narmor.get(3))

This will never be true.

 

You should be using EntityPlayer#getItemStackFromSlot(EntityEquipmentSlot)

Thanks, i never knew about many of the methods you so far have helped with.

7 hours ago, Merthew said:

Thanks, i never knew about many of the methods you so far have helped with.

To compare ItemStacks you need to compare the item and the metadata. ItemStack#getItem and ItemStack.getMetadata() It is also possible to use the utility functions in the ItemStack class. ItemStack.are.....

I just used isItemEqual(); and it seems to be working fine.