public class OpenInvCommand implements CommandExecutor {

    private int TaskID;

    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if (sender instanceof Player) {
            Player player = (Player) sender;
            Inventory inventory = Bukkit.createInventory(null, 9 * 1, "§aMenü");

            ItemStack item = new ItemStack(Material.GRAY_STAINED_GLASS_PANE);
            ItemMeta itemMeta = item.getItemMeta();
            itemMeta.setDisplayName("§7Bitte habe einen Moment geduld...");
            item.setItemMeta(itemMeta);
            inventory.addItem(item);
            for (int i = 0; i < 9; i++) {
                inventory.setItem(i, item);
                player.openInventory(inventory);
            }
            TaskID = Bukkit.getScheduler().scheduleSyncRepeatingTask(LoadingScreen.getPlugin(), new Runnable() {
                @Override
                public void run() {

                    ItemStack item = new ItemStack(Material.GREEN_STAINED_GLASS_PANE);
                    ItemMeta itemMeta = item.getItemMeta();
                    itemMeta.setDisplayName("");
                    item.setItemMeta(itemMeta);
                    inventory.addItem(item);
                    for (int i = 0; i < 9; i++) {
                        inventory.setItem(i, item);
                        player.openInventory(inventory);

                    Bukkit.getScheduler().cancelTask(TaskID);
                    }
                }
            }, 0, 40);
        }
        return false;
    }
}