Saving and loading player inventories to/from HashMaps

I am creating a plugin that saves the players inventory when they right click a sign that says "[SaveKit]" then loading the inventory when they right click a sign that says "[LoadKit]". Here is what i have:

The HashMaps :

public static HashMap<String, ItemStack[]> armor = new HashMap<String, ItemStack[]>();
public static HashMap<String, ItemStack[]> inv = new HashMap<String, ItemStack[]>();

The saveKit() and loadKit() :

public static void saveKit(Player player) {
    armor.put(player.getName(), player.getInventory().getArmorContents());
    inv.put(player.getName(), player.getInventory().getContents());
    player.sendMessage(tag + ChatColor.GREEN + " You have successfully saved your kit!");
}

public static void loadKit(Player player) {
    player.getInventory().setContents(inv.get(player.getName()));
    player.getInventory().setArmorContents(armor.get(player.getName()));
    player.sendMessage(tag + ChatColor.GREEN + " You have successfully loaded your kit!");
}

and finally, the onInteract(PlayerInteractEvent e)

@EventHandler
public void onInteract(PlayerInteractEvent e) {
    Player p = e.getPlayer();
    Action a = e.getAction();
    Block b = e.getClickedBlock();

    if (b == null) {
        return;
    }

    if (a == Action.RIGHT_CLICK_BLOCK && b != null && b.getType() == Material.WALL_SIGN) {
        Sign sign = (Sign) b.getState();

        if (ChatColor.stripColor(sign.getLine(0)).equalsIgnoreCase("[SaveKit]")) {
            saveKit(p);
            return;
        } else if (ChatColor.stripColor(sign.getLine(0)).equalsIgnoreCase("[LoadKit]")) {
            loadKit(p);
            return;
        }
    }
}

So everything here works so far, apart from loading and saving the inventories, the messages send which shows it is calling the load/saveKit methods, but it is not loading or saving the inventories. Please help! Thanks!