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Featured Replies

Posted

I am recieving a NullPointerException when sending a packet to the client, but I'm not sure what is actually null.

I know that my pipeline works, as I have sent packets the other way without a problem.

 

My packet system uses the Mantle library to simplify things.

 

Exception:

Spoiler

[01:16:30] [Server thread/ERROR] [FML]: SimpleChannelHandlerWrapper exception
java.lang.NullPointerException
    at net.minecraftforge.fml.common.network.FMLOutboundHandler$OutboundTarget$4.selectNetworks(FMLOutboundHandler.java:135) ~[FMLOutboundHandler$OutboundTarget$4.class:?]
    at net.minecraftforge.fml.common.network.FMLOutboundHandler.write(FMLOutboundHandler.java:297) ~[FMLOutboundHandler.class:?]
    at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:658) ~[AbstractChannelHandlerContext.class:4.0.23.Final]
    at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:716) ~[AbstractChannelHandlerContext.class:4.0.23.Final]
    at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:651) ~[AbstractChannelHandlerContext.class:4.0.23.Final]
    at io.netty.handler.codec.MessageToMessageEncoder.write(MessageToMessageEncoder.java:112) ~[MessageToMessageEncoder.class:4.0.23.Final]
    at io.netty.handler.codec.MessageToMessageCodec.write(MessageToMessageCodec.java:116) ~[MessageToMessageCodec.class:4.0.23.Final]
    at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:658) ~[AbstractChannelHandlerContext.class:4.0.23.Final]
    at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:716) ~[AbstractChannelHandlerContext.class:4.0.23.Final]
    at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:706) ~[AbstractChannelHandlerContext.class:4.0.23.Final]
    at io.netty.channel.AbstractChannelHandlerContext.writeAndFlush(AbstractChannelHandlerContext.java:741) ~[AbstractChannelHandlerContext.class:4.0.23.Final]
    at io.netty.channel.DefaultChannelPipeline.writeAndFlush(DefaultChannelPipeline.java:895) ~[DefaultChannelPipeline.class:4.0.23.Final]
    at io.netty.channel.AbstractChannel.writeAndFlush(AbstractChannel.java:240) ~[AbstractChannel.class:4.0.23.Final]
    at net.minecraftforge.fml.common.network.simpleimpl.SimpleNetworkWrapper.sendTo(SimpleNetworkWrapper.java:254) [SimpleNetworkWrapper.class:?]
    at alpvax.characteroverhaul.network.CharacterNetwork.sendTo(CharacterNetwork.java:45) [CharacterNetwork.class:?]
    at alpvax.characteroverhaul.api.character.CharacterBase.addAbility(CharacterBase.java:291) [CharacterBase.class:?]
    at TestPerks$1.onLevelChange(TestPerks.java:220) [TestPerks$1.class:?]
    at alpvax.characteroverhaul.api.character.CharacterBase.setPerkLevel(CharacterBase.java:157) [CharacterBase.class:?]
    at alpvax.characteroverhaul.api.character.CharacterBase.deserializeNBT(CharacterBase.java:459) [CharacterBase.class:?]
    at alpvax.characteroverhaul.api.character.CharacterBase.deserializeNBT(CharacterBase.java:1) [CharacterBase.class:?]
    at alpvax.characteroverhaul.capabilities.CharacterCapabilityProvider.deserializeNBT(CharacterCapabilityProvider.java:48) [CharacterCapabilityProvider.class:?]
    at alpvax.characteroverhaul.capabilities.CharacterCapabilityProvider.deserializeNBT(CharacterCapabilityProvider.java:1) [CharacterCapabilityProvider.class:?]
    at net.minecraftforge.common.capabilities.CapabilityDispatcher.deserializeNBT(CapabilityDispatcher.java:135) [CapabilityDispatcher.class:?]
    at net.minecraft.entity.Entity.readFromNBT(Entity.java:2019) [Entity.class:?]
    at net.minecraft.server.management.PlayerList.readPlayerDataFromFile(PlayerList.java:317) [PlayerList.class:?]
    at net.minecraft.server.management.PlayerList.initializeConnectionToPlayer(PlayerList.java:120) [PlayerList.class:?]
    at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.completeServerSideConnection(NetworkDispatcher.java:265) [NetworkDispatcher.class:?]
    at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.access$100(NetworkDispatcher.java:73) [NetworkDispatcher.class:?]
    at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher$1.update(NetworkDispatcher.java:214) [NetworkDispatcher$1.class:?]
    at net.minecraft.network.NetworkManager.processReceivedPackets(NetworkManager.java:308) [NetworkManager.class:?]
    at net.minecraft.network.NetworkSystem.networkTick(NetworkSystem.java:195) [NetworkSystem.class:?]
    at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:817) [MinecraftServer.class:?]
    at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:698) [MinecraftServer.class:?]
    at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:156) [IntegratedServer.class:?]
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:547) [MinecraftServer.class:?]
    at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]

addAbility:

public void addAbility(Ability ability)
	{
		if(!MinecraftForge.EVENT_BUS.post(new AbilityEvent.Add(this, ability)))
		{
			UUID id = ability.getID();
			Preconditions.checkArgument(!abilities.containsKey(id), "Already an ability with that id: %s", id);
			ability.onEquip();
			abilities.put(id, ability);
			if(getAttachedObject() instanceof EntityPlayerMP)
			{
				CharacterNetwork.sendTo(new AbilityChangedPacket(id, ability), getAttachedObject());
			}
		}
	}

 

Packet:

public class AbilityChangedPacket extends AbstractPacket.Threadsafe
{
	UUID id;
	Ability ability;

	public AbilityChangedPacket()
	{}

	public AbilityChangedPacket(@Nonnull UUID id, @Nullable Ability ability)
	{
		this.id = id;
		this.ability = ability;
	}

	@Override
	public void fromBytes(ByteBuf buf)
	{
		id = new UUID(buf.readLong(), buf.readLong());
		String name = ByteBufUtils.readUTF8String(buf);
		System.err.println(name);//XXX
		/*if(!name.equals("ability.remove"))
		{
			ability = ClientObjectFactoryRegistry.createAbility(name, CharacterOverhaul.proxy.getClientCharacter());
			if(ability != null)
			{
				ability.readClientData(ByteBufUtils.readTag(buf));
			}
		}*/
	}

	@Override
	public void toBytes(ByteBuf buf)
	{
		buf.writeLong(id.getMostSignificantBits());
		buf.writeLong(id.getLeastSignificantBits());
		/*if(ability != null)
		{
			ByteBufUtils.writeUTF8String(buf, ability.getClass().getName());
			ByteBufUtils.writeTag(buf, ability.getNBTForClientSync());
		}
		else
		{*/
			ByteBufUtils.writeUTF8String(buf, "ability.remove");
		//}
	}

	/*@Override
	public IMessage handleClient(NetHandlerPlayClient netHandler)
	{
		FMLCommonHandler.instance().getWorldThread(netHandler).addScheduledTask(new Runnable()
		{
			@Override
			public void run()
			{
				//CharacterOverhaul.proxy.getClientCharacter().updateClientAbility(id, ability);
			}
		});
		return null;
	}
	
	@Override
	public IMessage handleServer(NetHandlerPlayServer netHandler)
	{
		throw new RuntimeException("AbilityChangedPacket recieved on server! How did this happen!");
	}*/

	@Override
	public void handleClientSafe(NetHandlerPlayClient netHandler)
	{
		//CharacterOverhaul.proxy.getClientCharacter().updateClientAbility(id, ability);
	}

	@Override
	public void handleServerSafe(NetHandlerPlayServer netHandler)
	{
		throw new RuntimeException("AbilityChangedPacket recieved on server! How did this happen!");
	}

}

 

  • Author

What is the recommended way to sync capability data if it needs to be synced each time the entity is loaded from NBT?

Edited by Alpvax
More detail

  • Author

I have a system which reads acquired perks from NBT, then sets the perk level accordingly. Setting the perk level could add abilities, and adding abilities sends a packet to the client to add them client-side.

 

What would be the best way of implementing this?

16 minutes ago, Alpvax said:

I have a system which reads acquired perks from NBT, then sets the perk level accordingly. Setting the perk level could add abilities, and adding abilities sends a packet to the client to add them client-side.

 

What would be the best way of implementing this?

diesieben's explanation should work for your system. The server reads its stored data from NBT when the player is read, then you can use PlayLoggedInEvent (and the others) to send that data to the client for an initial sync.

  • Author

What about supporting other entities? Would it be better to use the join world event?

 

EDIT: Clearly wasn't thinking straight, most people wouldn't try to send packets to the client who has connected as a creeper!

Edited by Alpvax
Stupid question

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