SetItem works just once

I'm trying to make a plugin that teleport players and separates inventories between worlds. Everything works fine, but the inventory lines works just once.

I'm using this for saving the inventory in a yml file.

Code:

FileConfiguration config = plugin.getConfig();
config.set("Config.Jugadores."+Jugador.getUniqueId()+".CordsOW.Inventario", Jugador.getInventory().getContents());
plugin.saveConfig();

And this for set the inventory.

Code:

List<ItemStack> items = (List<ItemStack>) config.getList("Config.Jugadores."+Jugador.getUniqueId()+".CordsOW.Inventario");
for (int i=0;i<Jugador.getInventory().getSize();i++) {
    Jugador.getInventory().setItem(i,items.get(i)); //Console says the error is in this line
}

What am I doing wrong? I'm new to both java and bukkit.

 

Can you paste the error here

 

Yeah, sorry I didn't do it before.

Code:

[12:53:11] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'mundo' in plugin uwu v1.0.0
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:149) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    at org.bukkit.craftbukkit.v1_15_R1.CraftServer.dispatchCommand(CraftServer.java:723) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.PlayerConnection.handleCommand(PlayerConnection.java:1658) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.PlayerConnection.a(PlayerConnection.java:1498) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.PacketPlayInChat.a(PacketPlayInChat.java:47) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.PlayerConnectionUtils.lambda$0(PlayerConnectionUtils.java:19) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.TickTask.run(SourceFile:18) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeTask(SourceFile:144) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.executeNext(SourceFile:118) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.MinecraftServer.ba(MinecraftServer.java:918) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.MinecraftServer.executeNext(MinecraftServer.java:911) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.IAsyncTaskHandler.awaitTasks(SourceFile:127) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.MinecraftServer.sleepForTick(MinecraftServer.java:895) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:828) [spigot.jar:git-Spigot-2f5d615-d07a78b]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_241]
Caused by: java.lang.NullPointerException
    at eacrow.Comandos.mundo.onCommand(mundo.java:93) ~[?:?]
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[spigot.jar:git-Spigot-2f5d615-d07a78b]
    ... 17 more

 

this means that something is undefined and where it is at (mundo.java:93) if you're in intelij (not sure about eclipse) you can click mundo.java:93 and it will take you there. With the infomation you've provided that's the best i can help you.

 

If you still have the problem, Can you share an example of how it looks when saved in config @Eacrow

 

I had problems with the hard drive and I lost the file, sorry

 

@Eacrow Did you check if the inventory saved has 27 slots in the config ? i dun remember if the saving method skip null slot of save it

 

@Legendary_zotar Ok I recreate it, it's stored this way

Code:

        Inventario:
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: WOODEN_AXE
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: COMPASS
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: OAK_LOG
          amount: 64
        - null
        - null
        - null
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: DIAMOND_BOOTS
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: SPRUCE_PLANKS
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: SPRUCE_PLANKS
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: SPRUCE_PLANKS
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: SPRUCE_PLANKS
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - null
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: SPRUCE_PLANKS
          amount: 60
        - null
        - null
        - ==: org.bukkit.inventory.ItemStack
          v: 2230
          type: CHAINMAIL_BOOTS
          meta:
            ==: ItemMeta
            meta-type: UNSPECIFIC
            Damage: 2
        - null
        - null
        - null
        - null

@caderapee It seems that it saves more than 27 slots, although it worked, but only once, for it to work again I had to restart the server.

 

@Eacrow
The error literally says "NullPointerException" when you're passing null values to the setItem method. You can't just save the inventory like that, org.bukkit.inventory.ItemStack means nothing at all to anyone.

You need a serialization method called something like "serializeInventory" which will save the config like the following:

Code:

1:
    type: DIAMOND_BOOTS
    quantity: 1
    enchantments:
           - enchant 1
           - enchant 2
    durability: 10
    etc...

For each slot in the inventory, incrementing 1 as you go through the slots.

Then create a deserializeInventory method that will just do the reverse.

 

So why does it work the first time?

 

@Eacrow
you should modify your code to:
Save items with they're slot number (so when loading you can set to same slot number)
and ignore Empty slots so it doesnt save as null
also some items like "Barrel" well save as null because its a 1.14+ item to fix that you can add "api-version: 1.14" or 1.15 to your plugin.yml