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Posted

I have made a custom packet using Forge's SimpleImpl packet system which is supposed to send a packet from the server to the client, but nothing seems to be happening. Am I doing something wrong?

SPacketRegisterFakePlayer.java:

package com.ptsmods.morecommands.miscellaneous;

import java.nio.charset.Charset;
import java.util.UUID;

import com.ptsmods.morecommands.miscellaneous.Reference.LogType;

import io.netty.buffer.ByteBuf;
import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraftforge.fml.common.FMLCommonHandler;
import net.minecraftforge.fml.common.network.simpleimpl.IMessage;
import net.minecraftforge.fml.common.network.simpleimpl.IMessageHandler;
import net.minecraftforge.fml.common.network.simpleimpl.MessageContext;

public class SPacketRegisterFakePlayer implements IMessage {

	private EntityPlayerMP player;

	public SPacketRegisterFakePlayer() {

	}

	public SPacketRegisterFakePlayer(EntityPlayerMP player) {
		this.player = player;
	}

	@Override
	public void fromBytes(ByteBuf buf) {
		UUID id = UUID.fromString(buf.readCharSequence(buf.readableBytes(), Charset.defaultCharset()).toString());
		Reference.print(LogType.INFO, "Reading packet data.", id.toString());
		try {
			player = FMLCommonHandler.instance().getMinecraftServerInstance().getPlayerList().getPlayerByUUID(id);
		} catch (Throwable e) {
			e.printStackTrace();
			return;
		}
	}

	@Override
	public void toBytes(ByteBuf buf) {
		Reference.print(LogType.INFO, "Writing packet data.");
		buf.writeCharSequence(player.getUniqueID().toString(), Charset.defaultCharset());
	}

	public EntityPlayerMP getPlayer() {
		return player;
	}

	public static class Handler implements IMessageHandler<SPacketRegisterFakePlayer, IMessage> {

		@Override
		public IMessage onMessage(SPacketRegisterFakePlayer message, MessageContext ctx) {
			Reference.print(LogType.INFO, "Processing packet data.");
			EntityPlayerMP player = message.getPlayer();
			Reference.fakePlayers.add(player);
			return null;
		}
	}

}

PacketDispatcher.java:

package com.ptsmods.morecommands.miscellaneous;

import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraftforge.fml.common.network.NetworkRegistry;
import net.minecraftforge.fml.common.network.NetworkRegistry.TargetPoint;
import net.minecraftforge.fml.common.network.simpleimpl.IMessage;
import net.minecraftforge.fml.common.network.simpleimpl.SimpleNetworkWrapper;
import net.minecraftforge.fml.relauncher.Side;
import net.minecraftforge.fml.relauncher.SideOnly;

public class PacketDispatcher {
	private static final SimpleNetworkWrapper DISPATCHER = NetworkRegistry.INSTANCE.newSimpleChannel(Reference.MOD_ID);

	public static void registerPackets() {
		DISPATCHER.registerMessage(SPacketRegisterFakePlayer.Handler.class, SPacketRegisterFakePlayer.class, 0, Side.CLIENT);
	}

	public static void sendTo(IMessage message, EntityPlayerMP player) {
		DISPATCHER.sendTo(message, player);
	}

	public static void sendToAll(IMessage message) {
		DISPATCHER.sendToAll(message);
	}

	public static void sendToAllAround(IMessage message, TargetPoint targetPoint) {
		DISPATCHER.sendToAllAround(message, targetPoint);
	}

	public static void sendToDimension(IMessage message, int dim) {
		DISPATCHER.sendToDimension(message, dim);
	}

	@SideOnly(Side.CLIENT)
	public static void sendToServer(IMessage message) {
		DISPATCHER.sendToServer(message);
	}

}

 

  • Author

In a command.

fakeplayer.java

package com.ptsmods.morecommands.commands;

import java.util.ArrayList;
import java.util.UUID;

import com.mojang.authlib.GameProfile;
import com.mojang.util.UUIDTypeAdapter;
import com.ptsmods.morecommands.miscellaneous.CommandType;
import com.ptsmods.morecommands.miscellaneous.PacketDispatcher;
import com.ptsmods.morecommands.miscellaneous.Permission;
import com.ptsmods.morecommands.miscellaneous.Reference;
import com.ptsmods.morecommands.miscellaneous.SPacketRegisterFakePlayer;

import net.minecraft.command.ICommandSender;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraft.network.EnumPacketDirection;
import net.minecraft.network.NetHandlerPlayServer;
import net.minecraft.network.NetworkManager;
import net.minecraft.server.MinecraftServer;
import net.minecraft.server.management.PlayerInteractionManager;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.GameType;

public class fakePlayer {

	public fakePlayer() {
	}

	public static class CommandfakePlayer extends com.ptsmods.morecommands.miscellaneous.CommandBase {

		@Override
		public java.util.List getAliases() {
			ArrayList aliases = new ArrayList();
			return aliases;
		}

		@Override
		public java.util.List getTabCompletions(MinecraftServer server, ICommandSender sender, String[] args, BlockPos pos) {
			return new ArrayList();
		}

		@Override
		public String getName() {
			return "fakeplayer";
		}

		@Override
		public String getUsage(ICommandSender sender) {
			return usage;
		}

		@Override
		public void execute(MinecraftServer server, ICommandSender sender, String[] args) {
			if (args.length != 0) {
				if (args[0].length() > 16) Reference.sendMessage(sender, "The name has to be 16 characters at most.");
				else {
					Reference.sendMessage(sender, "Creating the fake player, please stand still, this will only take a few seconds.");
					EntityPlayer player = (EntityPlayer) sender;
					String uuid = Reference.getUUIDFromName(args[0]);
					GameProfile profile = new GameProfile(uuid == null ? UUID.randomUUID() : UUIDTypeAdapter.fromString(uuid), args[0]);
					EntityPlayerMP fakePlayer = new EntityPlayerMP(server, server.getWorld(player.dimension), profile, new PlayerInteractionManager(player.world));
					NetworkManager netManager = new NetworkManager(EnumPacketDirection.CLIENTBOUND);
					server.getPlayerList().initializeConnectionToPlayer(netManager, fakePlayer, new NetHandlerPlayServer(server, netManager, fakePlayer));
					Reference.fakePlayers.add(fakePlayer);
					for (EntityPlayerMP player1 : server.getPlayerList().getPlayers())
						if (!Reference.fakePlayers.contains(player1)) PacketDispatcher.sendTo(new SPacketRegisterFakePlayer(fakePlayer), player1);
					fakePlayer.setPositionAndRotation(0, 0, 0, player.rotationYaw, player.rotationPitch);
					fakePlayer.setPositionAndUpdate(player.posX, player.posY, player.posZ);
					fakePlayer.setGameType(GameType.CREATIVE);
					Reference.sendMessage(sender, "The player " + fakePlayer.getName() + " has been made with the UUID " + fakePlayer.getUniqueID().toString() + ".");
				}
			} else Reference.sendCommandUsage(sender, usage);
		}

		@Override
		public CommandType getCommandType() {
			return CommandType.SERVER;
		}

		@Override
		public Permission getPermission() {
			return new Permission(Reference.MOD_ID, "fakeplayer", "Permission to use the fakeplayer command.", true);
		}

		private String usage = "/fakeplayer <name> Creates a fake player.";

	}

}

 

  • Author

Alright, I got the message to be sent to the client now, but it crashes and gives me an error. Any ideas on why?

Stacktrace:

[15:52:49] [Netty Local Client IO #1/ERROR] [FML]: FMLIndexedMessageCodec exception caught
io.netty.handler.codec.DecoderException: java.lang.NullPointerException: Undefined message for discriminator 0 in channel morecommands
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:98) ~[MessageToMessageDecoder.class:4.1.9.Final]
	at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111) ~[MessageToMessageCodec.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) [DefaultChannelPipeline$HeadContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) [DefaultChannelPipeline.class:4.1.9.Final]
	at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:274) [EmbeddedChannel.class:4.1.9.Final]
	at net.minecraftforge.fml.common.network.internal.FMLProxyPacket.processPacket(FMLProxyPacket.java:108) [FMLProxyPacket.class:?]
	at net.minecraft.network.NetworkManager.channelRead0(NetworkManager.java:155) [NetworkManager.class:?]
	at net.minecraft.network.NetworkManager.channelRead0(NetworkManager.java:49) [NetworkManager.class:?]
	at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [SimpleChannelInboundHandler.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.handleClientSideCustomPacket(NetworkDispatcher.java:409) [NetworkDispatcher.class:?]
	at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.channelRead0(NetworkDispatcher.java:274) [NetworkDispatcher.class:?]
	at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.channelRead0(NetworkDispatcher.java:74) [NetworkDispatcher.class:?]
	at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [SimpleChannelInboundHandler.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) [DefaultChannelPipeline$HeadContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) [DefaultChannelPipeline.class:4.1.9.Final]
	at io.netty.channel.local.LocalChannel.finishPeerRead0(LocalChannel.java:443) [LocalChannel.class:4.1.9.Final]
	at io.netty.channel.local.LocalChannel.access$500(LocalChannel.java:49) [LocalChannel.class:4.1.9.Final]
	at io.netty.channel.local.LocalChannel$5.run(LocalChannel.java:397) [LocalChannel$5.class:4.1.9.Final]
	at io.netty.channel.DefaultEventLoop.run(DefaultEventLoop.java:54) [DefaultEventLoop.class:4.1.9.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) [SingleThreadEventExecutor$5.class:4.1.9.Final]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_144]
Caused by: java.lang.NullPointerException: Undefined message for discriminator 0 in channel morecommands
	at net.minecraftforge.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:99) ~[FMLIndexedMessageToMessageCodec.class:?]
	at net.minecraftforge.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:40) ~[FMLIndexedMessageToMessageCodec.class:?]
	at io.netty.handler.codec.MessageToMessageCodec$2.decode(MessageToMessageCodec.java:81) ~[MessageToMessageCodec$2.class:4.1.9.Final]
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:88) ~[MessageToMessageDecoder.class:4.1.9.Final]
	... 33 more
[15:52:50] [Netty Local Client IO #1/ERROR] [FML]: There was a critical exception handling a packet on channel morecommands
io.netty.handler.codec.DecoderException: java.lang.NullPointerException: Undefined message for discriminator 0 in channel morecommands
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:98) ~[MessageToMessageDecoder.class:4.1.9.Final]
	at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111) ~[MessageToMessageCodec.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) ~[DefaultChannelPipeline$HeadContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) ~[DefaultChannelPipeline.class:4.1.9.Final]
	at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:274) ~[EmbeddedChannel.class:4.1.9.Final]
	at net.minecraftforge.fml.common.network.internal.FMLProxyPacket.processPacket(FMLProxyPacket.java:108) [FMLProxyPacket.class:?]
	at net.minecraft.network.NetworkManager.channelRead0(NetworkManager.java:155) [NetworkManager.class:?]
	at net.minecraft.network.NetworkManager.channelRead0(NetworkManager.java:49) [NetworkManager.class:?]
	at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [SimpleChannelInboundHandler.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.handleClientSideCustomPacket(NetworkDispatcher.java:409) [NetworkDispatcher.class:?]
	at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.channelRead0(NetworkDispatcher.java:274) [NetworkDispatcher.class:?]
	at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.channelRead0(NetworkDispatcher.java:74) [NetworkDispatcher.class:?]
	at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [SimpleChannelInboundHandler.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) [DefaultChannelPipeline$HeadContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) [DefaultChannelPipeline.class:4.1.9.Final]
	at io.netty.channel.local.LocalChannel.finishPeerRead0(LocalChannel.java:443) [LocalChannel.class:4.1.9.Final]
	at io.netty.channel.local.LocalChannel.access$500(LocalChannel.java:49) [LocalChannel.class:4.1.9.Final]
	at io.netty.channel.local.LocalChannel$5.run(LocalChannel.java:397) [LocalChannel$5.class:4.1.9.Final]
	at io.netty.channel.DefaultEventLoop.run(DefaultEventLoop.java:54) [DefaultEventLoop.class:4.1.9.Final]
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) [SingleThreadEventExecutor$5.class:4.1.9.Final]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_144]
Caused by: java.lang.NullPointerException: Undefined message for discriminator 0 in channel morecommands
	at net.minecraftforge.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:99) ~[FMLIndexedMessageToMessageCodec.class:?]
	at net.minecraftforge.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:40) ~[FMLIndexedMessageToMessageCodec.class:?]
	at io.netty.handler.codec.MessageToMessageCodec$2.decode(MessageToMessageCodec.java:81) ~[MessageToMessageCodec$2.class:4.1.9.Final]
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:88) ~[MessageToMessageDecoder.class:4.1.9.Final]
	... 33 more
[15:52:50] [Netty Local Client IO #1/ERROR] [FML]: Network Disconnect: A fatal error has occurred, this connection is terminated

SPacketRegisterFakePlayer.java:

package com.ptsmods.morecommands.miscellaneous;

import java.nio.charset.Charset;
import java.util.UUID;

import com.ptsmods.morecommands.miscellaneous.Reference.LogType;

import io.netty.buffer.ByteBuf;
import net.minecraft.entity.player.EntityPlayerMP;
import net.minecraftforge.fml.common.FMLCommonHandler;
import net.minecraftforge.fml.common.network.simpleimpl.IMessage;
import net.minecraftforge.fml.common.network.simpleimpl.IMessageHandler;
import net.minecraftforge.fml.common.network.simpleimpl.MessageContext;

public class SPacketRegisterFakePlayer implements IMessage {

	private EntityPlayerMP player;

	public SPacketRegisterFakePlayer() {

	}

	public SPacketRegisterFakePlayer(EntityPlayerMP player) {
		this.player = player;
	}

	@Override
	public void fromBytes(ByteBuf buf) {
		UUID id = UUID.fromString(buf.readCharSequence(buf.readableBytes(), Charset.defaultCharset()).toString());
		Reference.print(LogType.INFO, "Reading packet data.", id.toString());
		try {
			player = FMLCommonHandler.instance().getMinecraftServerInstance().getPlayerList().getPlayerByUUID(id);
		} catch (Throwable e) {
			e.printStackTrace();
			return;
		}
	}

	@Override
	public void toBytes(ByteBuf buf) {
		Reference.print(LogType.INFO, "Writing packet data.");
		buf.writeCharSequence(player.getUniqueID().toString(), Charset.defaultCharset());
	}

	public EntityPlayerMP getPlayer() {
		return player;
	}

	public static class Handler implements IMessageHandler<SPacketRegisterFakePlayer, IMessage> {

		@Override
		public IMessage onMessage(SPacketRegisterFakePlayer message, MessageContext ctx) {
			Reference.print(LogType.INFO, "Processing packet data.");
			EntityPlayerMP player = message.getPlayer();
			Reference.fakePlayers.add(player);
			return null;
		}
	}

}

 

Are you registering the packet on both the server and client side (with the same discriminant, obviously) ?  The error message suggests the packet isn't registered on the client side, although I don't have an IDE to hand right now to verify that.

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