I'm currently messing around with the persisted NBT tag in the player, and the integer won't save:

	NBTTagCompound nbt = player.getEntityData().getCompoundTag(EntityPlayer.PERSISTED_NBT_TAG);
	nbt.setInteger("EnderStorageExp", nbt.getInteger("EnderStorageExp") + 1);

 

I have this code inside of a packet that gets called pretty frequently. Here's the full class:

package enderstorage.network;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraft.nbt.NBTTagCompound;
import enderstorage.EnderStorage;

public class PacketRequestChangeExp extends AbstractPacket {
public int exp = 0;

public PacketRequestChangeExp setExp(int exp) {
	this.exp = exp;
	return this;
}

@Override
public void encodeInto(ChannelHandlerContext ctx, ByteBuf buffer) {
	buffer.writeInt(exp);
}

@Override
public void decodeInto(ChannelHandlerContext ctx, ByteBuf buffer) {
	exp = buffer.readInt();
}

@Override
public void handleClientSide(EntityPlayer player) {
}

@Override
public void handleServerSide(EntityPlayer player) {
	NBTTagCompound nbt = player.getEntityData().getCompoundTag(EntityPlayer.PERSISTED_NBT_TAG);
	nbt.setInteger("EnderStorageExp", nbt.getInteger("EnderStorageExp") + 1);
	EnderStorage.packetHandler.sendTo(new PacketRefreshExp().setExp(nbt.getInteger("EnderStorageExp")), (EntityPlayerMP) player);
}
}

 

The default value of the tag is 0. When it's 0 and the code it called, it goes up to 1. If it's 1, it just keeps setting itself to 1.

It would appear you aren't storing your key, not the integer, so when you call the get method it just returns 0 by default. Never done anything like this before though so I couldn't shed any light on how to fix that.

Random question, maybe the cause it isn't stored? Why is this:

public PacketRequestChangeExp setExp(int exp) {
	this.exp = exp;
	return this;
}

returning a packetrequest object if you never use it? It looks like it is meant to be a void, and you use it like that is there any reason it is set up this way?

The exp field isn't used in anything right now.

 

It returns itself so I can do this:

packetHandler.setToServer(new PacketRequestChangeExp().setExp(10));

Hmm, it seems that writing to the persisted nbt tag compount doesn't work. :I

@Override
// why are you handling the server side only, or at all, when you should just be setting the server side
// data directly via a method to setXP? Are you setting xp on the client side and then sending a packet?
public void handleServerSide(EntityPlayer player) {
NBTTagCompound nbt = player.getEntityData().getCompoundTag(EntityPlayer.PERSISTED_NBT_TAG);
// and here, you are only adding 1 rather than the exp amount from the packet
// so it doesn't matter what you "set" the packet xp to
nbt.setInteger("EnderStorageExp", nbt.getInteger("EnderStorageExp") + 1);
// here you send a packet to the client, but you never handle that packet
EnderStorage.packetHandler.sendTo(new PacketRefreshExp().setExp(nbt.getInteger("EnderStorageExp")), (EntityPlayerMP) player);
}

@Override
public void handleClientSide(EntityPlayer player) {
// see? nothing here...
}

Can you show the code where you add or set the xp initially, rather than just your packet class? Where are you sending this packet from?

I'm sending this from a GUI

package enderstorage.gui;

import net.minecraft.client.gui.GuiButton;
import net.minecraft.client.gui.inventory.GuiContainer;
import net.minecraft.client.resources.I18n;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.util.ResourceLocation;

import org.lwjgl.opengl.GL11;

import cpw.mods.fml.relauncher.Side;
import cpw.mods.fml.relauncher.SideOnly;
import enderstorage.EnderStorage;
import enderstorage.container.ContainerExpEnderChest;
import enderstorage.network.PacketRequestChangeExp;
import enderstorage.network.PacketRequestRefresh;
import enderstorage.tileentity.TileEntityExpEnderChest;

//854, 480
@SideOnly(Side.CLIENT)
public class GuiExpEnderChest extends GuiContainer {
private static final ResourceLocation texture = new ResourceLocation("enderstorage:textures/gui/expEnderChest.png");
private EntityPlayer player;

public GuiExpEnderChest(TileEntityExpEnderChest chest, EntityPlayer player) {
	super(new ContainerExpEnderChest(chest));
	this.ySize = 88;
	this.player = player;
}

public void initGui() {
	super.initGui();
	this.buttonList.add(new GuiButton(0, this.width / 2 - 83, this.height / 2 - 10, 20, 20, I18n.format("<<<", new Object[0])));
	this.buttonList.add(new GuiButton(1, this.width / 2 - 63, this.height / 2 - 10, 20, 20, I18n.format("<<", new Object[0])));
	this.buttonList.add(new GuiButton(2, this.width / 2 - 43, this.height / 2 - 10, 20, 20, I18n.format("<", new Object[0])));
	this.buttonList.add(new GuiButton(3, this.width / 2 + 63, this.height / 2 - 10, 20, 20, I18n.format(">>>", new Object[0])));
	this.buttonList.add(new GuiButton(4, this.width / 2 + 43, this.height / 2 - 10, 20, 20, I18n.format(">>", new Object[0])));
	this.buttonList.add(new GuiButton(5, this.width / 2 + 23, this.height / 2 - 10, 20, 20, I18n.format(">", new Object[0])));
	EnderStorage.packetHandler.sendToServer(new PacketRequestRefresh());
}

protected void drawGuiContainerForegroundLayer(int p_146979_1_, int p_146979_2_) {
	String s = I18n.format("container.expEnderChest", new Object[0]);
	this.fontRendererObj.drawString(s, this.xSize / 2 - this.fontRendererObj.getStringWidth(s) / 2, 6, 4210752);
	s = I18n.format("container.expEnderChest.stored", new Object[0]);
	this.fontRendererObj.drawString(s, this.xSize / 2 - this.fontRendererObj.getStringWidth(s) / 2, 35, 4210752);
	s = "" + EnderStorage.currentStored;
	int x = this.xSize / 2 - this.fontRendererObj.getStringWidth(s) / 2;
	int y = 45;
	this.fontRendererObj.drawString(s, x + 1, y, 0);
	this.fontRendererObj.drawString(s, x - 1, y, 0);
	this.fontRendererObj.drawString(s, x, y + 1, 0);
	this.fontRendererObj.drawString(s, x, y - 1, 0);
	this.fontRendererObj.drawString(s, x, y, 8453920);
}

protected void drawGuiContainerBackgroundLayer(float p_146976_1_, int p_146976_2_, int p_146976_3_) {
	GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
	this.mc.getTextureManager().bindTexture(texture);
	int k = (this.width - this.xSize) / 2;
	int l = (this.height - this.ySize) / 2;
	this.drawTexturedModalRect(k, l, 0, 0, this.xSize, this.ySize);
}

protected void actionPerformed(GuiButton b) {
	switch(b.id) {
	case (0):
		EnderStorage.packetHandler.sendToServer(new PacketRequestChangeExp().setExp(-10));
		break;
	case (1):
		EnderStorage.packetHandler.sendToServer(new PacketRequestChangeExp().setExp(-5));
		break;
	case (2):
		EnderStorage.packetHandler.sendToServer(new PacketRequestChangeExp().setExp(-1));
		break;
	case (3):
		EnderStorage.packetHandler.sendToServer(new PacketRequestChangeExp().setExp(10));
		break;
	case (4):
		EnderStorage.packetHandler.sendToServer(new PacketRequestChangeExp().setExp(5));
		break;
	case (5):
		EnderStorage.packetHandler.sendToServer(new PacketRequestChangeExp().setExp(1));
		break;
	}
}
}

 

I'm not using the exp field because I'm just testing with it.

 

Also the PacketRefreshExp is sent to the client so it'll display it on their gui.

Right, you're sending it from a GUI, that's fine, but you're not using the value that you send. Did you not read my comments? And when you send your packet back to the client, you don't do anything with it, so of course you're not going to see an updated value in the GUI.

I'm not sending the exact packet back. This is the PacketRefreshExp code:

package enderstorage.network;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraft.nbt.NBTTagCompound;
import enderstorage.EnderStorage;

public class PacketRequestChangeExp extends AbstractPacket {
public int exp = 0;

public PacketRequestChangeExp setExp(int exp) {
	this.exp = exp;
	return this;
}

@Override
public void encodeInto(ChannelHandlerContext ctx, ByteBuf buffer) {
	buffer.writeInt(exp);
}

@Override
public void decodeInto(ChannelHandlerContext ctx, ByteBuf buffer) {
	exp = buffer.readInt();
}

@Override
public void handleClientSide(EntityPlayer player) {
}

@Override
public void handleServerSide(EntityPlayer player) {
	NBTTagCompound nbt = player.getEntityData().getCompoundTag(EntityPlayer.PERSISTED_NBT_TAG);
	System.err.println("Stored: " + nbt.getInteger("EnderStorageExp"));
	nbt.setInteger("EnderStorageExp", nbt.getInteger("EnderStorageExp") + 1);
	EnderStorage.packetHandler.sendTo(new PacketRefreshExp().setExp(nbt.getInteger("EnderStorageExp")), (EntityPlayerMP) player);
}
}

 

As stated before, I'm not using the exp field because I'm testing with it.

 

Additionally, it updates the client just fine.

Where is the code for PacketRefreshExp? I keep seeing the code for PacketRequestChangeExp.

Sorry, I'm getting a bit sleepy.

 

package enderstorage.network;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import net.minecraft.entity.player.EntityPlayer;
import enderstorage.EnderStorage;

public class PacketRefreshExp extends AbstractPacket {
public int exp = 0;

public PacketRefreshExp setExp(int exp) {
	this.exp = exp;
	return this;
}

@Override
public void encodeInto(ChannelHandlerContext ctx, ByteBuf buffer) {
	buffer.writeInt(exp);
}

@Override
public void decodeInto(ChannelHandlerContext ctx, ByteBuf buffer) {
	exp = buffer.readInt();
}

@Override
public void handleClientSide(EntityPlayer player) {
	EnderStorage.currentStored = exp;
}

@Override
public void handleServerSide(EntityPlayer player) {
}
}

Ok, thanks. I had that code in a LivingSpawnEvent, but I guess I did something wrong.