Saving Inventory ArrayList

I'm writing a random loot chest plugin. The plugin will spawn loot inside of chests based on what's in the config file. I can set a chest to spawn loot. I'm setting the inventory in an ArrayList. The only problem is when the server reloads or restarts the ArrayList is empty. How can I keep the inventories of the chests I set as LootChests in the ArrayList when reloading? When I try saving the list to the config it doesn't seem to work when trying to save Inventories. Any way around this?

 

@Calebizzthaman What's your current code?

 

Code:

 public String prefix = ChatColor.RED + "[" + ChatColor.GOLD + "Chesty" + ChatColor.RED + "] ";
 
  public ArrayList<Player> chestymode = new ArrayList<>();
 
  public ArrayList<Inventory> lootchests = new ArrayList<>();
  String chests = lootchests.toString();
 
  public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
    if (command.getName().equalsIgnoreCase("chesty") &&
      sender instanceof Player)
      if (sender.isOp()) {
        if (!this.chestymode.contains(sender)) {
          this.chestymode.add((Player)sender);
          sender.sendMessage(prefix + ChatColor.GOLD + "Chesty mode " + ChatColor.RED + ChatColor.BOLD + "enabled");
        } else {
          this.chestymode.remove(sender);
          sender.sendMessage(prefix + ChatColor.GOLD + "Chesty mode " + ChatColor.RED + ChatColor.BOLD + "disabled");
        }
      } else {
        sender.sendMessage(prefix + " You do not have access to do this!");
      } 
    return true;
  }
 
  @EventHandler
  public void onPlayerSetLootChest(InventoryOpenEvent e) {
    Player player = (Player)e.getPlayer();
    Inventory chest = e.getInventory();
    if(!(lootchests.contains(chest))) {
        if (chestymode.contains(player)) {
            if(player.isSneaking()) {
                if(e.getInventory().getType() == InventoryType.CHEST) {
                    e.setCancelled(true);
                    player.sendMessage(prefix + ChatColor.DARK_GREEN + "Loot Chest created");
                    lootchests.add(chest);
                    getConfig().set("chests", chests);
                }
            }
        }
       
    }
  }
 
  @EventHandler
  public void onPlayerOpenChest(InventoryOpenEvent e) {
    Inventory inventory = e.getInventory();
   
    Player player = (Player)e.getPlayer();
    List<String> configItems = getConfig().getStringList("Items");
   
    int index = new Random().nextInt(configItems.size());
    String items = configItems.get(index);
   
    ItemStack newItem = new ItemStack(Material.getMaterial(items.toUpperCase()));
   
    if(!(chestymode.contains(player))) {
        if(lootchests.contains(inventory)) {
            inventory.addItem(newItem);
            lootchests.remove(inventory);
            (new BukkitRunnable() {
                public void run() {
                    inventory.clear();
                    lootchests.add(inventory);
                }
            }).runTaskLater(Bukkit.getPluginManager().getPlugin("Chesty"), 1200);
       
   
  }

 

@Calebizzthaman You should save each ItemStack in the inventory individually, you should almost never save the result of toString().