NBT comparing, breaks on reload

Discussion in 'Plugin Development' started by PhantomUnicorns, Jul 17, 2017.

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    I'm trying to test if a item matches another item, pretty simple. The items have a display name and NBT. Using ItemStack#isSimilar(ItemStack) it's pretty easy. But once I add NBT, it works except when I reload my server. Then it doesn't work, and only works for the newest version of the item (I give the item onEnable to all players, I set the NBT the same exact way each time (I don't change the code at all)). When I don't add NBT, it works. Anyone know why/how to fix? If so, I would like a solution that takes into account NBT values.

    I'll be able to respond in about 20-40minutes, sorry for the delay!
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    Are you sure the NBT tags are carrying over across reloads? It sounds as though one of the itemstack's you're comparing is missing that NBT tag.
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    I'm sure, because I'm setting the generic.armor for the slot mainhand, and it still works (increasing my armor). But it doesn't register as the same item. It's weird because #isSimilar doesn't even look at NBT data
    Last edited: Jul 17, 2017
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    Actually, the implementation of isSimilar in CraftItemStack looks at NBT tags. From CraftItemStack#isSimilar():
    1. this.handle.getTag().equals(that.handle.getTag())
    This would strongly suggest that the tags aren't saving properly. Can we see your code?

    When I use this code, everything works flawlessly, I see that the NBT tags are there after the restart, AND they pass isSimilar():
    1. @Override
    2. public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
    3. if (!(sender instanceof Player)) {
    4. return true;
    5. }
    6. if (args.length == 1) {
    7. Player player = ((Player) sender);
    8. switch (args[0]) {
    9. case "additem": {
    10. ItemStack itemStack = new ItemStack(Material.BLAZE_ROD);
    11. NBTUtil.NBTTagCompound compound = new NBTUtil.NBTTagCompound();
    12. compound.setString("testString", "abc...åäö");
    13. itemStack = NBTUtil.setItemNBT(itemStack, compound);
    14. player.getInventory().addItem(itemStack);
    15. break;
    16. }
    17. case "compare": {
    18. ItemStack itemStack = player.getInventory().getItemInMainHand();
    19. ItemStack itemStack2 = player.getInventory().getItemInOffHand();
    20. sender.sendMessage(String.valueOf(itemStack.isSimilar(itemStack2)));
    21. break;
    22. }
    23. case "printNBT": {
    24. ItemStack itemStack = player.getInventory().getItemInMainHand();
    25. ItemStack itemStack2 = player.getInventory().getItemInOffHand();
    26. sender.sendMessage("Main hand: " + NBTUtil.getItemNBT(itemStack));
    27. sender.sendMessage("Off hand: " + NBTUtil.getItemNBT(itemStack2));
    28. break;
    29. }
    30. }
    31. }
    32. return true;
    33. }
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    EDIT: I see why it's going bad :p, when I set the generic.armor to the slot mainhand, I have to supply a random uuid least and most. This uuid is a new random each time, but is requried to set it. I'm trying to think of a fix of it now, if anyone has a fix then my ears are open. Just to clear up what I said:
    SETINT_METHOD.invoke(comp, "UUIDLeast", (int) uuid.getMostSignificantBits());
    SETINT_METHOD.invoke(comp, "UUIDMost", (int) uuid.getMostSignificantBits());
    That's some reflection code that I use in it, it's doing:
    comp.setInt("UUIDLeast", (int) uuid.getMostSignificantBits());
    comp.setInt("UUIDMost", (int) uuid.getMostSignificantBits());
    UUID being:
    UUID uuid = UUID.randomUUID();
    The different UUID's I found that it returns:
    • 3372873788163047964
    • 808927740789542364
    • It can return more, just showing why it's not returning true for isSimilar
    EDIT: can anyone tell me why UUIDLeast and UUIDMost even need to be set/set to? I get the other tags I'm setting, but I don't get that one (I went with the flow of the tutorials I found online).

    EDIT: I got it to work! But if anyone could explain UUIDLeast and UUIDMost it would be a lifesaver!

    EDIT: Ik now that UUIDLeast and UUIDMost matter because if items have the same of both, they don't work together (They don't stack effects!)
    Last edited: Jul 18, 2017
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    Well, write your own isSimilar method where you check everything just like before but you don't compare the UUID bits?
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    Yeah that's what I'm going to do once I have time :p
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