Adding items to chests from arraylist

Hi. I have an error in my code when the chests order in the arraylist is shuffled, and the materials in an arraylist are added into those chests in the new order. I think I have got the top right, but I am not sure what to do with the bottom when the server adds the items. Thanks

Code:java

@EventHandler
    public void fillChests(PlayerJoinEvent event) {
        List<Material> materials = new ArrayList<>();
        List<Block> chests = new ArrayList<>();
 
        Location chest1 = new Location(Bukkit.getWorld("world"), 25, 25, 100);
 
        Location chest2 = new Location(Bukkit.getWorld("world"), 26, 26, 100);
 
        Location chest3 = new Location(Bukkit.getWorld("world"), 27, 27, 100);
 
        Location chest4 = new Location(Bukkit.getWorld("world"), 27, 27, 100);
 
        Location chest5 = new Location(Bukkit.getWorld("world"), 27, 27, 100);
 
        Location chest6 = new Location(Bukkit.getWorld("world"), 27, 27, 100);
 
        Location chest7 = new Location(Bukkit.getWorld("world"), 27, 27, 100);
 
        Location chest8 = new Location(Bukkit.getWorld("world"), 27, 27, 100);
 
        Location chest9 = new Location(Bukkit.getWorld("world"), 27, 27, 100);
 
        Location chest10 = new Location(Bukkit.getWorld("world"), 27, 27, 100);
 
        Material mat1 = Material.BOWL;
        materials.add(mat1);
 
        Material mat2 = Material.APPLE;
        materials.add(mat1);
 
        Material mat3 = Material.BED;
        materials.add(mat1);
 
        Material mat4 = Material.COOKIE;
        materials.add(mat1);
 
        Material mat5 = Material.BAKED_POTATO;
        materials.add(mat1);
 
        Material mat6 = Material.ARROW;
        materials.add(mat1);
 
        Material mat7 = Material.BOOK;
        materials.add(mat1);
 
        Material mat8 = Material.COMPASS;
        materials.add(mat1);
 
        Material mat9 = Material.ANVIL;
        materials.add(mat1);
 
        Material mat10 = Material.DIRT;
        materials.add(mat1);
 
        Block a = chest1.getBlock();
        Block b = chest1.getBlock();
        Block c = chest1.getBlock();
        Block d = chest1.getBlock();
        Block e = chest1.getBlock();
        Block f = chest1.getBlock();
        Block g = chest1.getBlock();
        Block h = chest1.getBlock();
        Block i = chest1.getBlock();
        Block j = chest1.getBlock();
 
        while (a.getType().equals(Material.CHEST) ||
            b.getType().equals(Material.CHEST) ||
            c.getType().equals(Material.CHEST) ||
            d.getType().equals(Material.CHEST) ||
            e.getType().equals(Material.CHEST) ||
            f.getType().equals(Material.CHEST) ||
            g.getType().equals(Material.CHEST) ||
            h.getType().equals(Material.CHEST) ||
            i.getType().equals(Material.CHEST) ||
            j.getType().equals(Material.CHEST)) {
            Chest nchest1 = (Chest) a.getState();
            Chest nchest2 = (Chest) b.getState();
            Chest nchest3 = (Chest) c.getState();
            Chest nchest4 = (Chest) d.getState();
            Chest nchest5 = (Chest) e.getState();
            Chest nchest6 = (Chest) f.getState();
            Chest nchest7 = (Chest) g.getState();
            Chest nchest8 = (Chest) h.getState();
            Chest nchest9 = (Chest) i.getState();
            Chest nchest10 = (Chest) j.getState();
 
            Inventory chestinv1 = nchest1.getInventory();
            chests.add((Block) chestinv1);
            Inventory chestinv2 = nchest2.getInventory();
            chests.add((Block) chestinv2);
            Inventory chestinv3 = nchest3.getInventory();
            chests.add((Block) chestinv3);
            Inventory chestinv4 = nchest4.getInventory();
            chests.add((Block) chestinv4);
            Inventory chestinv5 = nchest5.getInventory();
            chests.add((Block) chestinv5);
            Inventory chestinv6 = nchest6.getInventory();
            chests.add((Block) chestinv6);
            Inventory chestinv7 = nchest7.getInventory();
            chests.add((Block) chestinv7);
            Inventory chestinv8 = nchest8.getInventory();
            chests.add((Block) chestinv8);
            Inventory chestinv9 = nchest9.getInventory();
            chests.add((Block) chestinv9);
            Inventory chestinv10 = nchest10.getInventory();
            chests.add((Block) chestinv10);
 
            Collections.shuffle(chests);
            while (true) {
                chests.get(0).getState().getData().add(materials.get(0));
                chests.get(1).getState().getData().add(materials.get(1));
                chests.get(2).getState().getData().add(materials.get(2));
                chests.get(3).getState().getData().add(materials.get(3));
                chests.get(4).getState().getData().add(materials.get(4));
                chests.get(5).getState().getData().add(materials.get(5));
                chests.get(6).getState().getData().add(materials.get(6));
                chests.get(7).getState().getData().add(materials.get(7));
                chests.get(8).getState().getData().add(materials.get(8));
                chests.get(9).getState().getData().add(materials.get(9));
            }
        }
    }

By the way, the add method is erroring. Just to let anyone who wants to help know.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

You should post the full stacktrace.

By the way, learn how to use a for loop alongside a List (which contains the chests) instead of creating a new variable for each chest block

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

It did do that but it came up with a error.

 

Wow... well first off yes learn how to use a for statement. Secondly, you should really use ItemStacks when adding. To make an ItemStack given Material, do:

Code:java

ItemStack item = new ItemStack(mat);

 

Don't worry. I have figured it out...