MySQL - Store player inventory in database

Hi guys,

I want to store player inventories into a MySQL database, but I am lost. What is the best way to store the inventories?

Greetings,
Sebastiaan

 

Props to Hellsing:

Code:java

package de.thehellscode.core.util;
 
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.math.BigInteger;
 
import net.minecraft.server.v1_5_R2.NBTBase;
import net.minecraft.server.v1_5_R2.NBTTagCompound;
import net.minecraft.server.v1_5_R2.NBTTagList;
 
import org.bukkit.craftbukkit.v1_5_R2.inventory.CraftInventoryCustom;
import org.bukkit.craftbukkit.v1_5_R2.inventory.CraftItemStack;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.PlayerInventory;
 
public class InventoryUtil
{
    public static Inventory getArmorInventory(PlayerInventory inventory)
    {
        ItemStack[] armor = inventory.getArmorContents();
        CraftInventoryCustom storage = new CraftInventoryCustom(null, armor.length);
 
        for (int i = 0; i < armor.length; i++)
            storage.setItem(i, armor[i]);
 
        return storage;
    }
 
    public static Inventory getContentInventory(PlayerInventory inventory)
    {
        ItemStack[] content = inventory.getContents();
        CraftInventoryCustom storage = new CraftInventoryCustom(null, content.length);
 
        for (int i = 0; i < content.length; i++)
            storage.setItem(i, content[i]);
 
        return storage;
    }
 
    public static String toBase64(Inventory inventory)
    {
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        DataOutputStream dataOutput = new DataOutputStream(outputStream);
        NBTTagList itemList = new NBTTagList();
        // Save every element in the list
        for (int i = 0; i < inventory.getSize(); i++)
        {
            NBTTagCompound outputObject = new NBTTagCompound();
            net.minecraft.server.v1_5_R2.ItemStack craft = getCraftVersion(inventory.getItem(i));
            // Convert the item stack to a NBT compound
            if (craft != null)
                craft.save(outputObject);
            itemList.add(outputObject);
        }
 
        // Now save the list
        NBTBase.a(itemList, dataOutput);
 
        // Serialize that array
        return new BigInteger(1, outputStream.toByteArray()).toString(32);
        // return encodeBase64(outputStream.toByteArray());
    }
 
    public static Inventory fromBase64(String data)
    {
        ByteArrayInputStream inputStream = new ByteArrayInputStream(new BigInteger(data, 32).toByteArray());
        // ByteArrayInputStream inputStream = new
        // ByteArrayInputStream(decodeBase64(data));
        NBTTagList itemList = (NBTTagList) NBTBase.b(new DataInputStream(inputStream));
        Inventory inventory = new CraftInventoryCustom(null, itemList.size());
 
        for (int i = 0; i < itemList.size(); i++)
        {
            NBTTagCompound inputObject = (NBTTagCompound) itemList.get(i);
            // IsEmpty
            if (!inputObject.isEmpty())
            {
                inventory.setItem(i, CraftItemStack.asBukkitCopy(net.minecraft.server.v1_5_R2.ItemStack.createStack(inputObject)));
            }
        }
        // Serialize that array
        return inventory;
    }
 
    private static net.minecraft.server.v1_5_R2.ItemStack getCraftVersion(ItemStack stack)
    {
        if (stack != null)
            return CraftItemStack.asNMSCopy(stack);
 
        return null;
    }
}
[/i][/i]

Update it to 1.6.4 cant to it now!

 

That wouldn't save the player inventory, so that I can acces it on other servers. Right?

 

Look into http://jd.bukkit.org/rb/apidocs/org/bukkit/util/io/BukkitObjectInputStream.html and http://jd.bukkit.org/rb/apidocs/org/bukkit/util/io/BukkitObjectOutputStream.html , which would allow writing an inventory to a file.

If you're set on making something in sql, you can write ItemStacks to a ConfigurationSection (since they are serializable), and then save that ConfigurationSection in a "text" field within SQL.

 

"New Look into http://jd.bukkit.org/rb/apidocs/org/bukkit/util/io/BukkitObjectInputStream.html and http://jd.bukkit.org/rb/apidocs/org/bukkit/util/io/BukkitObjectOutputStream.html , which would allow writing an inventory to a file." Yeah, I know what that does But thank you for your reaction, I'll look at it ASAP

 

If you're interested, I made a version of Hellsing 's code that uses reflection to avoid issues across updates:

See it here on github

All this code does, though, is save/restore an inventory to a string.

At that point, it's up to you to insert/select that string in and out of a database. From what I understand, Bukkit has a built-in DB API, so you should definitely start there. I think it's a bit tricky to set up but once you get it going it should be pretty easy to do what you want.

Now please bear with me for a few notes, I think it's important to manage your expectations

• If all you want to save is one string (inventory) per player, a flat file would probably be much easier (though I'm generally a big fan of storing data in databases rather than abusing a config file format....)
• What database your data will actually go into is up to the server admin, who can configure Bukkit as she likes. I think by default is uses SQLLite. I mention this because you say "MySQL" in the title, though I'm thinking it shouldn't really matter where your data gets stored
• Storing data in a database is just about persistence, so the data can be read later (e.g. after server reboot). This does not mean that data is somehow available to other servers.

That last part is perhaps the most important, you haven't really shared your end goal with us, but I get the impression you might be trying to do something that doesn't really involve database at all (at least, not within Bukkit)
Maybe let us know what you're trying to do, and we could help with general suggestions?

 

Well, I am developing a game like MineZ (just to give you an idea) and we are going to run multiple servers for that game. I want to store the player inventories in a database so that I can sync it between our servers. Anyways, thanks for your reaction!

 

What you really should do is look into the code of InventorySQL. Even he is making heavy use of annotations you should be able to see how its done.

Hint: https://github.com/ExoNetwork/Inven...datahandling/serializer/BukkitSerializer.java

Technically an object has to be brought into a serialiseable form.

Checkout the ItemStack serialise and deserialise method.

A Map<String, Object> is created. Mostly the Data is converted to a string representation.

When this is done recursively then you will have a Map that can be stored as binary large object (Blob) inside a database.

So the main part is the following (Taken from stackoverflow for easy demonstration)

Code:java

 
public static void main(String[] args) throws Exception {
    // Create raw data.
    Map<Integer, String> data = new HashMap<Integer, String>();
    data.put(1, "hello");
    data.put(2, "world");
    System.out.println(data.toString());
 
    // Convert Map to byte array
    ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
    ObjectOutputStream out = new ObjectOutputStream(byteOut);
    out.writeObject(data);
 
    // Parse byte array to Map
    ByteArrayInputStream byteIn = new ByteArrayInputStream(byteOut.toByteArray());
    ObjectInputStream in = new ObjectInputStream(byteIn);
    Map<Integer, String> data2 = (Map<Integer, String>) in.readObject();
    System.out.println(data2.toString());
}
 

So as this is just demonstration code you would obviously have to do the "write to database part".

What you have to do is get the bytes from the serialised byte array and store this in a blob to your database. Do not use a Text since it will produce too much overhead as text gets indexed plus is super ineffective not only because you can run into character encoding issues.

A blob will save you from running into those problems. This data does not have to be in a human readable form. If you need those informations you should optimize your database structure and create a table/index for this purpose only linking the ref_id to the blob data if needed.

Like if you need to fetch an item name many times from the database to lookup "items used" or whatever then you need a table for that. But going through all the object data in text form with the worst case "LIKE '%search%' ... good luck with that.

Anyways, as im working on a item storage engine myself you can monitor xAuth branch experimental if you like.

 

Are all your servers going to be on the same local network? A MySQL connection across the internet is usually not a good idea (mainly for security reasons), though you can do it.

So that said if you are the plugin author and the admin, then you have control I guess.

So I'm hoping you've looked here?

http://wiki.bukkit.org/Bukkit.yml#database

As well as here, following the relevant links to the APIs you can use to store and load objects?

http://wiki.bukkit.org/Plugin_Databases

The first link shows you how to configure Bukkit's db (it has an example for MySQL)

The second link points you towards how to use an ORM API to access that data from your plugin. It's not very hand-holdy, there may be some better resources out there, or even on this forum

That, combines with a method to serialize/deserialize an inventory, should be all the pieces you need to get and store inventories for players across servers. (I assume your plugin would load on login/enable and save on logout/disable?)