Posted September 11, 201312 yr Hello, I'm trying to use a class that implements IExtendedEntityProperties to add a currency to the player. I initialize the class when the player entity is constructed like so: @ForgeSubscribe(priority = EventPriority.NORMAL) public void onEntityConstuct(EntityConstructing event) { if (event.entity instanceof EntityPlayerMP) { EntityPlayerMP ep = (EntityPlayerMP) event.entity; ep.registerExtendedProperties(PlayerProperties.IDENTIFIER, new PlayerProperties()); } } The PlayerProperties class looks like so: public class PlayerProperties implements IExtendedEntityProperties { public static final String IDENTIFIER = "playerproperties"; public static PlayerProperties fromPlayer(EntityPlayerMP player) { return (PlayerProperties) player.getExtendedProperties(IDENTIFIER); } int credits = 0; EntityPlayerMP player; @Override public void saveNBTData(NBTTagCompound compound) { compound.setInteger("credits", credits); } @Override public void loadNBTData(NBTTagCompound compound) { if (compound.hasKey("credits")) { this.credits = compound.getInteger("credits"); } else { this.credits = 30; } sendPacket(); } @Override public void init(Entity entity, World world) { player = (EntityPlayerMP) entity; } private void sendPacket() { PacketDispatcher.sendPacketToPlayer(new PropertiesPacket(credits).makePacket(), (Player) player); } } Where my PropertiesPacket class looks like so: public class PropertiesPacket extends BasePacket { int credits; public PropertiesPacket(int credits) { this.credits = credits; } public PropertiesPacket() { } @Override public void write(ByteArrayDataOutput out) { out.writeInt(credits); } @Override public void read(ByteArrayDataInput in) { credits = in.readInt(); } @Override public void execute(EntityPlayer player, Side side) { if (side.isClient()) { PlayerData.credits = credits; // PlayerData is just a static client side class which stores the data. } } } Where the BasePacket class looks like this: public abstract class BasePacket { public static final String CHANNEL = "MyPacket"; private static final BiMap<Integer, Class<? extends BasePacket>> idMap; static { ImmutableBiMap.Builder<Integer, Class<? extends BasePacket>> builder = ImmutableBiMap.builder(); builder.put(Integer.valueOf(0), PropertiesPacket.class); idMap = builder.build(); } public static BasePacket constructPacket(int packetId) throws ProtocolException, ReflectiveOperationException { Class<? extends BasePacket> clazz = idMap.get(Integer.valueOf(packetId)); if (clazz == null) { throw new ProtocolException("Unknown Packet Id!"); } else { return clazz.newInstance(); } } public static class ProtocolException extends Exception { public ProtocolException() { } public ProtocolException(String message, Throwable cause) { super(message, cause); } public ProtocolException(String message) { super(message); } public ProtocolException(Throwable cause) { super(cause); } } public final int getPacketId() { if (idMap.inverse().containsKey(getClass())) { return idMap.inverse().get(getClass()).intValue(); } else { throw new RuntimeException("Packet " + getClass().getSimpleName() + " is missing a mapping!"); } } public final Packet makePacket() { ByteArrayDataOutput out = ByteStreams.newDataOutput(); out.writeByte(getPacketId()); write(out); return PacketDispatcher.getPacket(CHANNEL, out.toByteArray()); } public abstract void write(ByteArrayDataOutput out); public abstract void read(ByteArrayDataInput in); public abstract void execute(EntityPlayer player, Side side); } and my packet handler is as so: public class PacketHandler implements IPacketHandler { @Override public void onPacketData(INetworkManager manager, Packet250CustomPayload packet, Player player) { try { EntityPlayer entityPlayer = (EntityPlayer) player; ByteArrayDataInput in = ByteStreams.newDataInput(packet.data); int packetId = in.readUnsignedByte(); BasePacket basePacket = BasePacket.constructPacket(packetId); basePacket.read(in); basePacket.execute(entityPlayer, entityPlayer.worldObj.isRemote ? Side.CLIENT : Side.SERVER); } catch (ProtocolException e) { if (player instanceof EntityPlayerMP) { ((EntityPlayerMP) player).playerNetServerHandler.kickPlayerFromServer("Protocol Exception!"); Logger.getLogger("DemoMod").warning("Player " + ((EntityPlayer) player).username + " caused a Protocol Exception!"); } } catch (ReflectiveOperationException e) { throw new RuntimeException("Unexpected Reflection exception during Packet construction!", e); } } } However, when this code is run, it throws a null pointer exception and the packet isn't sent. Every time I've used this method of sending packets previously it's worked a charm, but this time it doesn't. The stack trace is: 2013-09-11 21:30:37 [iNFO] [sTDERR] java.lang.NullPointerException 2013-09-11 21:30:37 [iNFO] [sTDERR] at cpw.mods.fml.common.network.PacketDispatcher.sendPacketToPlayer(PacketDispatcher.java:45) 2013-09-11 21:30:37 [iNFO] [sTDERR] at mods.SaberMod.SaberValues.sendPacket(SaberValues.java:147) 2013-09-11 21:30:37 [iNFO] [sTDERR] at mods.SaberMod.SaberValues.loadNBTData(SaberValues.java:76) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.entity.Entity.readFromNBT(Entity.java:1647) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.server.management.ServerConfigurationManager.readPlayerDataFromFile(ServerConfigurationManager.java:239) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.server.management.ServerConfigurationManager.initializeConnectionToPlayer(ServerConfigurationManager.java:113) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.server.integrated.IntegratedServerListenThread.networkTick(IntegratedServerListenThread.java:97) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.updateTimeLightAndEntities(MinecraftServer.java:689) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:585) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:129) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:482) 2013-09-11 21:30:37 [iNFO] [sTDERR] at net.minecraft.server.ThreadMinecraftServer.run(ThreadMinecraftServer.java:16) which points to this line in the packet dispatcher: public static void sendPacketToPlayer(Packet packet, Player player) { if (player instanceof EntityPlayerMP) { ((EntityPlayerMP)player).playerNetServerHandler.sendPacketToPlayer(packet); //<-- this one } } This suggests the player in its own variables is wrong, the player's missing the server handler or the packet is null. I'm assuming the packet is null, but I don't see why this one shouldn't work while the others do. What is the likely problem here?
September 11, 201312 yr Author How do I use breakpoints, I've inserted one on the line, generated the exception, but cannot find the values of variables etc. (Using eclipse IDE)
September 12, 201312 yr Author I've applied a conditional breakpoint for if the server handler is null and it is. How can I send the information to the player?
September 12, 201312 yr Author Yeah, thanks for that it really cleared up a load of my code and helped me get much more organized I'll look into that now EDIT: thanks this has now worked for me
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