[1.18.2] Get world data file path

[J3ramy]

Hello together,

I want to save custom data in JSON format in the world's data folder.

How can I retrieve the path to it?

 

Thanks for your help!

[J3ramy]

Ok thank you.

Would I still be able to get the data in a screen container class?

[J3ramy]

Ok I will figure it out when my attempt now is not working.

Right now I am trying to send a CompoundNBT from the server to client.

My class looks like that:

Spoiler

public class SCPacketSendServerData {
    private final Server server;

    public SCPacketSendServerData(PacketBuffer buf){
        System.out.println("1");
        System.out.println(buf.readCompoundTag().getCompound("db")); //Null for some reason
      	System.out.println(buf.readString()); // TEST is printed
    }

    public SCPacketSendServerData(Server server){
        this.server = server;
    }

    public void toBytes(PacketBuffer buf){
        System.out.println("2");
        buf.writeCompoundTag(server.getData().getCompound("db")); //Normal object with all its contents
      	buf.writeString("TEST")
    }
}

 

As you can see I am writing my compound tag in toBytes. The tag is not null - I can get all the contents of the Server class.

But in my constructor the compount tag is null.

If I use a string instead it works fine. Can you find my mistake?

[J3ramy]

Ok, I changed my class to:

 

Spoiler

package de.j3ramy.economy.network;

import de.j3ramy.economy.screen.ServerScreen;
import de.j3ramy.economy.utils.Server;
import net.minecraft.client.Minecraft;
import net.minecraft.client.gui.screen.Screen;
import net.minecraft.network.PacketBuffer;
import net.minecraftforge.fml.network.NetworkEvent;

import java.util.function.Supplier;

public class SCPacketSendServerData {
    private final Server server;

    public SCPacketSendServerData(PacketBuffer buf){
        System.out.println("1");
        System.out.println(buf.readCompoundTag()); //null
    }

    public SCPacketSendServerData(Server server){
        this.server = server;
    }

    public void toBytes(PacketBuffer buf){
        System.out.println("2");
        System.out.println(server.getData().getCompound("db")); //all good
        buf.writeCompoundTag(server.getData().getCompound("db"));
        System.out.println(buf.readCompoundTag()); // ERROR: Caused by: java.io.IOException: Root tag must be a named compound tag
    }

    public void handle(Supplier<NetworkEvent.Context> ctx){
        ctx.get().enqueueWork(() ->{
            System.out.println("3");
        });
        ctx.get().setPacketHandled(true);
    }
}

 

As you can see this error gets created when I try to print it after I saved it. And I don't really know what this error means, because the tag has a name ("db")

[J3ramy]

Ah okay this was actually just for debug purpose. But good to know.

So, in there data not set yet, because it gets set there. Am I right?

 

But I don't get it why it's still null in the constructor

EDIT: It works now for some reason.

 

Another question: Is there a limit in how many content an nbt tag can save? E. g. can I add thousands of strings? Or is the limit actually the space on the hard disk?

Edited July 10, 2022 by J3ramy

[warjort]

There are some "hidden" limits which you might hit.

e.g. StringTag.write() uses DataOutput.writeUTF() which has this in its javadoc

Quote

First,
     * the total number of bytes needed to represent
     * all the characters of {@code s} is
     * calculated. If this number is larger than
     * {@code 65535}, then a {@code UTFDataFormatException}
     * is thrown.

[J3ramy]

Perfect.

Thank you @diesieben07 and @warjort!