1.14.4 Problems in serializing itemstack into yaml

There were some problems when I tried to use the following code:

Code (Text):

    public Quest(ConfigurationSection config) {
        name = config.getString("name");
        weekend = config.getBoolean("weekend");
        displayItem = config.getItemStack("displayItem");
    }

Yaml is as follows:

Code (YAML):

name: "Test"

weekend: true

displayItem:
  ==: org.bukkit.inventory.ItemStack
  type: TORCH
  meta:
    ==: ItemMeta
    meta-type: UNSPECIFIC
    display-name: "§e§l[ §c§l Test Quest §e§l]"
    lore:
     - "§aTarget:"
      - " §fGet 64 torches"
      - ""
      - "§dRewards:"
      - " §f50$ | 10Points"

When my plug-n is running normally (I'm sure it can run in 1.12.2 and below), I can normally see the display items and accept and complete the Quest.
However, when I transferred the plugin to 1.14.4, there was an exception: the lore of the display item disappeared!
I speculate that this is because the itemstack serialization code in 1.14.4 has changed, so I try to use the test code to serialize an itemstack into yaml to facilitate observation of its structure.

Code (Java):

            YamlConfiguration yml = new YamlConfiguration();
            ItemStack stack = new ItemStack(Material.DIAMOND_SWORD);
            ItemMeta meta = stack.getItemMeta();
            List<String> lore = new ArrayList<>();
            lore.add("test lore");
            meta.addEnchant(Enchantment.DAMAGE_ALL, 1, true);
            meta.setDisplayName("test item");
            meta.setLore(lore);
            meta.addItemFlags(ItemFlag.values());
            stack.setItemMeta(meta);
            yml.set("testItem", stack);
            try {
                yml.save(new File(getDataFolder(), "test.yml"));
            } catch (IOException e) {
                e.printStackTrace();
            }

I got the following yaml:

Code (YAML):

testItem:
  ==: org.bukkit.inventory.ItemStack
  v: 1976
  type: LEGACY_DIAMOND_SWORD
  meta:
    ==: ItemMeta
    meta-type: UNSPECIFIC
    display-name: test item
    lore:
   - test lore
    enchants:
      DAMAGE_ALL: 1
    ItemFlags:
   - HIDE_ENCHANTS
    - HIDE_ATTRIBUTES
    - HIDE_UNBREAKABLE
    - HIDE_DESTROYS
    - HIDE_PLACED_ON
    - HIDE_POTION_EFFECTS

I noticed that in itemstack in 1.14.4, there is an attribute V, which may be related to the answer I want.
So I added V: 1976 to all the exhibits in my mission document.
I thought he could run normally, but I was too naive.
This time, it's not that the item doesn't have lore, but the whole file can't be loaded!

Code (Text):

[14:17:15] [nioEventLoopGroup-3-1/ERROR]: Could not call method 'public static org.bukkit.inventory.ItemStack org.bukkit.inventory.ItemStack.deserialize(java.util.Map)' of class org.bukkit.inventory.ItemStack for deserialization
java.lang.IllegalArgumentException: Material cannot be null
    at org.apache.commons.lang.Validate.notNull(Validate.java:192) ~[spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:70) ~[spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.inventory.ItemStack.<init>(ItemStack.java:58) ~[spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.inventory.ItemStack.deserialize(ItemStack.java:490) ~[spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source) ~[?:?]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_241]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_241]
    at org.bukkit.configuration.serialization.ConfigurationSerialization.deserializeViaMethod(ConfigurationSerialization.java:85) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.configuration.serialization.ConfigurationSerialization.deserialize(ConfigurationSerialization.java:127) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.configuration.serialization.ConfigurationSerialization.deserializeObject(ConfigurationSerialization.java:207) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.configuration.file.YamlConstructor$ConstructCustomObject.construct(YamlConstructor.java:37) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructObjectNoCheck(BaseConstructor.java:204) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:193) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping2ndStep(BaseConstructor.java:453) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.SafeConstructor.constructMapping2ndStep(SafeConstructor.java:184) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructMapping(BaseConstructor.java:434) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.SafeConstructor$ConstructYamlMap.construct(SafeConstructor.java:521) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.configuration.file.YamlConstructor$ConstructCustomObject.construct(YamlConstructor.java:28) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructObjectNoCheck(BaseConstructor.java:204) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructObject(BaseConstructor.java:193) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.BaseConstructor.constructDocument(BaseConstructor.java:159) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.constructor.BaseConstructor.getSingleData(BaseConstructor.java:146) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.Yaml.loadFromReader(Yaml.java:524) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.yaml.snakeyaml.Yaml.load(Yaml.java:437) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.configuration.file.YamlConfiguration.loadFromString(YamlConfiguration.java:54) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:160) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.configuration.file.FileConfiguration.load(FileConfiguration.java:128) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.configuration.file.YamlConfiguration.loadConfiguration(YamlConfiguration.java:183) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at cn.hamster3.dailyquest.DataManager.init(DataManager.java:83) [DailyQuest.jar:?]
    at cn.hamster3.dailyquest.DailyQuest.reload(DailyQuest.java:77) [DailyQuest.jar:?]
    at cn.hamster3.dailyquest.listener.QuestListener.onServiceReceive(QuestListener.java:350) [DailyQuest.jar:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_241]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_241]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_241]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_241]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:316) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:70) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:529) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:508) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at cn.hamster3.service.spigot.ServiceReadHandler.channelRead0(ServiceReadHandler.java:12) [HamsterService.jar:?]
    at cn.hamster3.service.spigot.ServiceReadHandler.channelRead0(ServiceReadHandler.java:8) [HamsterService.jar:?]
    at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:284) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1434) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:965) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:647) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:582) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:499) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:461) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:884) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) [spigot.jar:git-Spigot-cbd1a1b-009d8af]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_241]

Later, I tried to decompile spigot.jar and found the code for itemstack. I find it seems to be related to bukkit. Getunsafe(). Getdataversion()! But I'm not sure what the problem is.
Recall some changes in the API in 1.13 (material enumeration fields changed a lot).
At first, I thought that the V attribute might be used to make the upgrade from the lower version plugin to the higher version consistent?
But obviously not! Otherwise, why can my plugin run in 1.12.2 instead of 1.14.4?
I speculate that this V attribute may be related to the item of data attribute, but for technical reasons, I am not sure whether the problem must be here.
In summary, I tried several ways:
Do not add V attribute - > no lore
Add V attribute - > some items will cause an error
Delete the V attribute of the items that will report an error - > the item lore disappears again
So what should I do to make sure that part of my items are both lore and not wrong?

My English is not very good, so maybe I can't express it clearly in some places. I'm very sorry if I offend you.

 

I just investigated a lot of data and found that in version 1.14.4, the V attribute of all itemstacks is the same value (1976), while in 1.14.3, all items are the same value (1968). So I guess this property is related to version
Maybe it's a good way to use JSON to store data, but if I do, all my code about itemstack will be rewritten (yes, I do write a lot of code directly deserializing itemstack with the bukkit API). These codes are distributed in different projects, and it may take a lot of time to complete it
So I need to figure out how this V attribute works