Solved Help with giving mobs gear

Hi, I am making a plugin that will have a chance of giving mobs buffs and gear when they spawn. However, I cannot get them to get the gear. Any help?

Code:

@EventHandler
    public void onCreatureSpawn(CreatureSpawnEvent mob) {
        if (mob.getEntityType() == EntityType.ZOMBIE) {
            if (!(getConfig().getInt("zombie") == 0)) {
                int random = (int)(Math.random()* getConfig().getInt("zombie") ) + 1;
                    if (random == 1) {
                        mob.getEntity().addPotionEffect(new PotionEffect(PotionEffectType.INCREASE_DAMAGE, 99999, 3));
                        mob.getEntity().addPotionEffect(new PotionEffect(PotionEffectType.FIRE_RESISTANCE, 99999, 1));
                        mob.getEntity().addPotionEffect(new PotionEffect(PotionEffectType.DAMAGE_RESISTANCE, 99999, 4));
                        mob.getEntity().setHealth(40);
                        mob.getEntity().setCanPickupItems(true);
                        mob.getEntity().getEquipment().setItemInHand(new ItemStack(Material.DIAMOND_SWORD));
                        mob.getEntity().getEquipment().setHelmet(new ItemStack(Material.DIAMOND_HELMET));
                        mob.getEntity().getEquipment().setChestplate(new ItemStack(Material.DIAMOND_CHESTPLATE));
                        mob.getEntity().getEquipment().setLeggings(new ItemStack(Material.DIAMOND_LEGGINGS));
                        mob.getEntity().getEquipment().setBoots(new ItemStack(Material.DIAMOND_BOOTS));
                        mob.getEntity().getEquipment().getItemInHand().addUnsafeEnchantment(Enchantment.DAMAGE_ALL, 5);
                        mob.getEntity().getEquipment().getItemInHand().addUnsafeEnchantment(Enchantment.DAMAGE_ARTHROPODS, 5);
                        mob.getEntity().getEquipment().getItemInHand().addUnsafeEnchantment(Enchantment.DAMAGE_UNDEAD, 5);
                        mob.getEntity().getEquipment().getItemInHand().addUnsafeEnchantment(Enchantment.LOOT_BONUS_MOBS, 10);
                        mob.getEntity().getEquipment().setItemInHandDropChance(100);
                        mob.getEntity().setCustomName(ChatColor.DARK_GREEN + "Zombie Boss");
                        mob.getEntity().setCustomNameVisible(true);
                }
            }
        }
    }

The potion effects work, just not the gear.