Player player = event.getPlayer();
ItemStack item = new ItemStack(Material.DIAMOND_PICKAXE, 1);
ItemMeta meta = item.getItemMeta();
meta.addEnchant(Enchantment.DIG_SPEED, 5, true);
meta.addEnchant(Enchantment.DURABILITY, 3, true);
meta.addEnchant(Enchantment.LOOT_BONUS_BLOCKS, 3, true);
item.setItemMeta(meta);
if(player.getInventory().contains(item)) player.getInventory().remove(item);