io.netty.handler.codec.DecoderException with SimpleNetworkWrapper

[WorldsEnder]

Hello guys, I have a problem with the following code:

 

@Mod(modid = MHFCReference.main_modid, name = MHFCReference.main_name, version = MHFCReference.main_version)
public class MHFCMain {
@Mod.Instance(MHFCReference.main_modid)
public static MHFCMain instance;

public static Logger logger;
public static final PacketPipeline packetPipeline = new PacketPipeline();

@Mod.EventHandler
public void preInit(FMLPreInitializationEvent pre) {
	logger = pre.getModLog();
	packetPipeline.registerPacket(MessageAttackHandler.class,
			MessageAIAttack.class, Side.CLIENT);
}
}
///------ PacketPipeline.java
// import.....
public class PacketPipeline {
public final SimpleNetworkWrapper networkPipe = NetworkRegistry.INSTANCE
		.newSimpleChannel("MHFC");
private int discriminator = 0;

public <REQ extends IMessage, ANS extends IMessage> void registerPacket(
		Class<? extends IMessageHandler<REQ, ANS>> messageHandler,
		Class<REQ> requestMessageType, Side side) {
	if (discriminator == 255) {
		MHFCMain.logger
				.error("Tried to register more than 256 message types");
		return;
	}
	MHFCMain.logger
			.info(String
					.format("Registered message %s with Handler %s for Side %s at Side %s with discriminator 0x%x",
							requestMessageType, messageHandler, side,
							MHFCMain.proxy.getSide(), discriminator));
	networkPipe.registerMessage(messageHandler, requestMessageType,
			discriminator++, side);
}
}

////-------------- MessageAIAttack.java
//import....;

public class MessageAIAttack<T extends EntityLivingBase & IMangedAttacks<T>>
	implements
		IMessage {
private int entityId;
private int attackIndex;

public MessageAIAttack(T entity, int attackIndex) {
	this.entityId = entity.getEntityId();
	this.attackIndex = attackIndex;
}

@Override
public void fromBytes(ByteBuf buf) {
	entityId = buf.readInt();
	attackIndex = buf.readInt();
}

@Override
public void toBytes(ByteBuf buf) {
	buf.writeInt(entityId);
	buf.writeInt(attackIndex);
}

/**
 * Used to retrieve the meant actual entity on client side. May return
 * <code>null</code> if the entity isn't loaded on client side.
 *
 * @return the entity
 */
@SuppressWarnings("unchecked")
@SideOnly(Side.CLIENT)
public <U extends EntityLivingBase & IMangedAttacks<U>> IMangedAttacks<U> getEntity() {
	return (IMangedAttacks<U>) Minecraft.getMinecraft().theWorld
			.getEntityByID(entityId);
}

public int getAttackIndex() {
	return this.attackIndex;
}
}

/////---------MessageAttackHandler.java
//import...

public class MessageAttackHandler
	implements
		IMessageHandler<MessageAIAttack, IMessage> {
@Override
public IMessage onMessage(MessageAIAttack message, MessageContext ctx) {
	IMangedAttacks<?> entity = message.getEntity();
	entity.getAttackManager().setAttack(message.getAttackIndex());
	return null;
}
}

 

The message is sent from the AI on both sides with the following call:

	MHFCMain.packetPipeline.networkPipe.sendToAll(new MessageAIAttack<T>());

I get the following output (not full output but the important parts):

 

[22:02:23] [Client thread/INFO] [@MODID@]: Registered message class mhfc.net.common.network.message.MessageAIAttack with Handler class mhfc.net.common.network.message.MessageAttackHandler for Side CLIENT at Side CLIENT with discriminator 0x0

[22:02:50] [Netty Client IO #0/INFO] [FML]: Server protocol version 1

[22:02:50] [Netty IO #1/INFO] [FML]: Client protocol version 1

[22:02:50] [Netty IO #1/INFO] [FML]: Client attempting to join with 5 mods : [email protected],[email protected]_1710,[email protected],[email protected],@MODID@@@VERSION@

[22:02:50] [Netty IO #1/INFO] [FML]: Attempting connection with missing mods [] at CLIENT

[22:02:50] [Netty Client IO #0/INFO] [FML]: Attempting connection with missing mods [] at SERVER

[22:02:50] [server thread/INFO] [FML]: [server thread] Server side modded connection established

[22:02:50] [Client thread/INFO] [FML]: [Client thread] Client side modded connection established

[22:02:51] [server thread/INFO]: ForgeDevName[local:E:a5af9013] logged in with entity id 236 at (799.4960941023224, 9.4884669234807, 153.51916685673305)

[22:02:51] [server thread/INFO]: ForgeDevName joined the game

[22:02:53] [Client thread/ERROR] [FML]: FMLIndexedMessageCodec exception caught

io.netty.handler.codec.DecoderException: java.lang.NullPointerException: Undefined message for discriminator 0 in channel MHFC

at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:99) ~[MessageToMessageDecoder.class:?]

at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111) ~[MessageToMessageCodec.class:?]

at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337) [DefaultChannelHandlerContext.class:?]

at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323) [DefaultChannelHandlerContext.class:?]

at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785) [DefaultChannelPipeline.class:?]

at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:169) [EmbeddedChannel.class:?]

at cpw.mods.fml.common.network.internal.FMLProxyPacket.processPacket(FMLProxyPacket.java:86) [FMLProxyPacket.class:?]

at net.minecraft.network.NetworkManager.processReceivedPackets(NetworkManager.java:247) [NetworkManager.class:?]

at net.minecraft.client.Minecraft.runTick(Minecraft.java:2152) [Minecraft.class:?]

at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1039) [Minecraft.class:?]

at net.minecraft.client.Minecraft.run(Minecraft.java:961) [Minecraft.class:?]

at net.minecraft.client.main.Main.main(Main.java:164) [Main.class:?]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_05]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_05]

at java.lang.reflect.Method.invoke(Method.java:483) ~[?:1.8.0_05]

at net.minecraft.launchwrapper.Launch.launch(Launch.java:134) [launchwrapper-1.9.jar:?]

at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_05]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_05]

at java.lang.reflect.Method.invoke(Method.java:483) ~[?:1.8.0_05]

at GradleStart.bounce(GradleStart.java:107) [start/:?]

at GradleStart.startClient(GradleStart.java:100) [start/:?]

at GradleStart.main(GradleStart.java:55) [start/:?]

Caused by: java.lang.NullPointerException: Undefined message for discriminator 0 in channel MHFC

at cpw.mods.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:73) ~[FMLIndexedMessageToMessageCodec.class:?]

at cpw.mods.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:17) ~[FMLIndexedMessageToMessageCodec.class:?]

at io.netty.handler.codec.MessageToMessageCodec$2.decode(MessageToMessageCodec.java:81) ~[MessageToMessageCodec$2.class:?]

at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:89) ~[MessageToMessageDecoder.class:?]

... 24 more

[22:02:53] [Client thread/ERROR] [FML]: There was a critical exception handling a packet on channel MHFC

io.netty.handler.codec.DecoderException: java.lang.NullPointerException: Undefined message for discriminator 0 in channel MHFC

at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:99) ~[MessageToMessageDecoder.class:?]

at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111) ~[MessageToMessageCodec.class:?]

at io.netty.channel.DefaultChannelHandlerContext.invokeChannelRead(DefaultChannelHandlerContext.java:337) ~[DefaultChannelHandlerContext.class:?]

at io.netty.channel.DefaultChannelHandlerContext.fireChannelRead(DefaultChannelHandlerContext.java:323) ~[DefaultChannelHandlerContext.class:?]

at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:785) ~[DefaultChannelPipeline.class:?]

at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:169) ~[EmbeddedChannel.class:?]

at cpw.mods.fml.common.network.internal.FMLProxyPacket.processPacket(FMLProxyPacket.java:86) [FMLProxyPacket.class:?]

at net.minecraft.network.NetworkManager.processReceivedPackets(NetworkManager.java:247) [NetworkManager.class:?]

at net.minecraft.client.Minecraft.runTick(Minecraft.java:2152) [Minecraft.class:?]

at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1039) [Minecraft.class:?]

at net.minecraft.client.Minecraft.run(Minecraft.java:961) [Minecraft.class:?]

at net.minecraft.client.main.Main.main(Main.java:164) [Main.class:?]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_05]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_05]

at java.lang.reflect.Method.invoke(Method.java:483) ~[?:1.8.0_05]

at net.minecraft.launchwrapper.Launch.launch(Launch.java:134) [launchwrapper-1.9.jar:?]

at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.9.jar:?]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_05]

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_05]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_05]

at java.lang.reflect.Method.invoke(Method.java:483) ~[?:1.8.0_05]

at GradleStart.bounce(GradleStart.java:107) [start/:?]

at GradleStart.startClient(GradleStart.java:100) [start/:?]

at GradleStart.main(GradleStart.java:55) [start/:?]

Caused by: java.lang.NullPointerException: Undefined message for discriminator 0 in channel MHFC

at cpw.mods.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:73) ~[FMLIndexedMessageToMessageCodec.class:?]

at cpw.mods.fml.common.network.FMLIndexedMessageToMessageCodec.decode(FMLIndexedMessageToMessageCodec.java:17) ~[FMLIndexedMessageToMessageCodec.class:?]

at io.netty.handler.codec.MessageToMessageCodec$2.decode(MessageToMessageCodec.java:81) ~[MessageToMessageCodec$2.class:?]

at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:89) ~[MessageToMessageDecoder.class:?]

... 24 more

[WorldsEnder]

Doesn't the wrapper take care of the proper direction/prevent sending in the wrong direction? Nope, he doesn't, the Client will attempt to send un Unregistered Message afaik and that will fail (?why is it called DecoderException then?) diesieben07's solution works... as most of the times