itemToJson.java

private static JsonObject itemToJson(ItemStack item, boolean useIndex, int index) {
	if(item == null) return null;

	Gson gson = new GsonBuilder().create();
	// Map<String, Object> values = new LinkedHashMap<>();
	JsonObject values = new JsonObject();

	//Set data to variables
	int id = item.getTypeId();
	int amount = item.getAmount();
	int data = item.getDurability();
	int repairPenalty = 0;
	boolean hasMeta = item.hasItemMeta();
	String name = null, enchants = null;
	List<String> lore = null;
	Material mat = item.getType();
	JsonObject bookMeta = null, armorMeta = null, skullMeta = null, fwMeta = null;
	if(mat == Material.BOOK_AND_QUILL || mat == Material.WRITTEN_BOOK) bookMeta = BookSerialization.serializeBookMeta((BookMeta) item.getItemMeta());
	else if(mat == Material.ENCHANTED_BOOK) bookMeta = BookSerialization.serializeEnchantedBookMeta((EnchantmentStorageMeta) item.getItemMeta());
	else if(Util.isLeatherArmor(mat)) armorMeta = LeatherArmorSerialization.serializeArmor((LeatherArmorMeta) item.getItemMeta());
	else if(mat == Material.SKULL_ITEM) skullMeta = SkullSerialization.serializeSkull((SkullMeta) item.getItemMeta());
	else if(mat == Material.FIREWORK) fwMeta = FireworkSerialization.serializeFireworkMeta((FireworkMeta) item.getItemMeta());
	if(hasMeta) {
    		ItemMeta meta = item.getItemMeta();
    		if(meta.hasDisplayName()) name = meta.getDisplayName();
    		if(meta.hasLore()) lore = meta.getLore();
    		if(meta.hasEnchants()) enchants = EnchantmentSerialization.serializeEnchantments(meta.getEnchants());
    		if(meta instanceof Repairable && ((Repairable) meta).hasRepairCost()) repairPenalty = ((Repairable) meta).getRepairCost();
	}

	//Add variables to the JsonObject
	values.addProperty("id", id);
	values.addProperty("amount", amount);
	values.addProperty("data", data);
	if(useIndex) values.addProperty("index", index);
	if(name != null) values.addProperty("name", name);
	if(enchants != null) values.addProperty("enchantments", enchants);
	if(lore != null) values.add("lore", new JsonObject().getAsJsonArray(gson.toJson(lore)));
	if(repairPenalty != 0) values.addProperty("repairPenalty", repairPenalty);
	if(bookMeta != null && bookMeta.getAsJsonArray().size() > 0) values.add("book-meta", bookMeta);
	if(armorMeta != null && armorMeta.getAsJsonArray().size() > 0) values.add("armor-meta", armorMeta);
	if(skullMeta != null && skullMeta.getAsJsonArray().size() > 0) values.add("skull-meta", skullMeta);
	if(fwMeta != null && fwMeta.getAsJsonArray().size() > 0) values.add("firework-meta", fwMeta);

	return values;
}