Save ItemStack with NBT data to file (client-side)

[Saucier]

Hey.

I'm trying to save a set of data to a file (client-side only).

The set consists of Strings, Integers and ItemStacks. I used a JSON file at first, but I need a good way to save the NBT data of each ItemStack as well which doesn't seem to be a good way if I use JSON files(?).

So I'm looking for a good way to store such data. My first consideration was to use a .dat file, but I have no experience with them and don't know if that is the best choice here.

The data should be able to be saved at any time, not just after loading/exiting the world/server. For example, the player should be able to type in "/savedata" or "/loaddata" into the chat and the file gets saved/loaded instantly.

The file will be saved on client-side only. It's basically like a global config file which should be the same on any server the client is on.

 

So I looked around and found the WorldSavedData class which seems to handle dat files(?), but I'm not sure if that's the right one and if you can save those at any time.

 

Thank you for your time.

Edited March 9, 2017 by Saucier

[Choonster]

WorldSavedData only saves data to the disk on the logical server, so it's not really suitable for your purposes.

 

You can look at how MapStorage reads and writes WorldSavedData instances to .dat files using CompressedStreamTools, though you won't be able to use ISaveHandler#getMapFileFromName from the logical client (since the client-side implementation always returns null).

[Saucier]

So I basically just need to create a new NBTTagCompound, get the data from a stack and use StreamTools to write it to the FileOutputStream, right?

 

I used the following code to save a single stack to disc (Currently test.dat in the root directory). Anything wrong with it?

public static void saveStackToFile(ItemStack stack) {
        if (stack != null) {
            NBTTagCompound nbt = new NBTTagCompound();
            stack.writeToNBT(nbt);
            String file = "test.dat";
            try {
                FileOutputStream fileoutputstream = new FileOutputStream(file);
                CompressedStreamTools.writeCompressed(nbt, fileoutputstream);
                fileoutputstream.close();
            } catch (Exception exception) {
                exception.printStackTrace();
            }
        }
    }

 

Output (Added some custom NBTTag data for testing purposes):

 

If I want to load the stack I just have to get the file by CompressedStreamTools#readCompressed and create the stack with ItemStack#loadItemStackFromNBT, correct?

[Choonster]

16 minutes ago, Saucier said:

So I basically just need to create a new NBTTagCompound, get the data from a stack and use StreamTools to write it to the FileOutputStream, right?

 

I used the following code to save a single stack to disc (Currently test.dat in the root directory). Anything wrong with it?

 

public static void saveStackToFile(ItemStack stack) {
        if (stack != null) {
            NBTTagCompound nbt = new NBTTagCompound();
            stack.writeToNBT(nbt);
            String file = "test.dat";
            try {
                FileOutputStream fileoutputstream = new FileOutputStream(file);
                CompressedStreamTools.writeCompressed(nbt, fileoutputstream);
                fileoutputstream.close();
            } catch (Exception exception) {
                exception.printStackTrace();
            }
        }
    }

 

 

That looks mostly correct, but there are some minor changes I'd recommend:

• Only catch the most specific exception you have to, i.e. IOException rather than Exception. This lets other exceptions propagate upwards so they can be handled by Minecraft itself.
• Log the exception with a log4j Logger rather than just printing its stack trace. This will ensure it's formatted properly in the console and FML log.
• Consider using ItemStack#serializeNBT (from the INBTSerializable interface) rather than ItemStack#writeToNBT. This creates the NBTTagCompound for you and returns it.

 

 

16 minutes ago, Saucier said:

If I want to load the stack I just have to get the file by CompressedStreamTools#readCompressed and create the stack with ItemStack#loadItemStackFromNBT, correct?

 

That should be all you need, yes.

[Saucier]

Will do that.

Thank you very much