PacketDispatcher

public class PacketDispatcher
{
    // a simple counter will allow us to get rid of 'magic' numbers used during packet registration
    private static byte packetId = 0;
    private boolean used;

    /**
     * The SimpleNetworkWrapper instance is used both to register and send packets.
     * Since I will be adding wrapper methods, this field is private, but you should
     * make it public if you plan on using it directly.
     */
    private static final SimpleNetworkWrapper dispatcher = NetworkRegistry.INSTANCE.newSimpleChannel(Reference.MOD_ID);


    /**
     * Call this during pre-init or loading and register all of your packets (messages) here
     */
    public static final void registerPackets() {

        registerMessage(SyncTeleporterContents.class);

        // Packets handled on CLIENT

        // Packets handled on SERVER
        //registerMessage(OpenGuiMessage.class);

        // If you don't want to make a 'registerMessage' method, you can do it directly:
        //PacketDispatcher.dispatcher.registerMessage(SyncPlayerPropsMessage.class, SyncPlayerPropsMessage.class, packetId++, Side.CLIENT);
        //PacketDispatcher.dispatcher.registerMessage(OpenGuiMessage.class, OpenGuiMessage.class, packetId++, Side.SERVER);

        // The following two packets are not used in this demo, but have been used in my other mods
        // I include them here simply for the sake of demonstrating packets that can be sent to both sides

        // Bidirectional packets:
        //registerMessage(PlaySoundPacket.class);
        //registerMessage(AttackTimePacket.class);
    }

    /**
     * Registers an {@link AbstractMessage} to the appropriate side(s)
     */
    private static final <T extends AbstractMessage<T> & IMessageHandler<T, IMessage>> void registerMessage(Class<T> clazz) {
        // We can tell by the message class which side to register it on by using #isAssignableFrom (google it)

        // Also, one can see the convenience of using a static counter 'packetId' to keep
        // track of the current index, rather than hard-coding them all, plus it's one less
        // parameter to pass.
        if (AbstractMessage.AbstractClientMessage.class.isAssignableFrom(clazz)) {
            PacketDispatcher.dispatcher.registerMessage(clazz, clazz, packetId++, Side.CLIENT);
        } else if (AbstractMessage.AbstractServerMessage.class.isAssignableFrom(clazz)) {
            PacketDispatcher.dispatcher.registerMessage(clazz, clazz, packetId++, Side.SERVER);
        } else {
            // hopefully you didn't forget to extend the right class, or you will get registered on both sides
            PacketDispatcher.dispatcher.registerMessage(clazz, clazz, packetId, Side.CLIENT);
            PacketDispatcher.dispatcher.registerMessage(clazz, clazz, packetId++, Side.SERVER);
        }
    }

    //========================================================//
    // The following methods are the 'wrapper' methods; again,
    // this just makes sending a message slightly more compact
    // and is purely a matter of stylistic preference
    //========================================================//



    /**
     * Send this message to the specified player's client-side counterpart.
     * See {@link SimpleNetworkWrapper#sendTo(IMessage, EntityPlayerMP)}
     */
    public static final void sendTo(IMessage message, EntityPlayerMP player) {
        PacketDispatcher.dispatcher.sendTo(message, player);
    }

    /**
     * Send this message to everyone.
     * See {@link SimpleNetworkWrapper#sendToAll(IMessage)}
     */
    public static void sendToAll(IMessage message) {
        PacketDispatcher.dispatcher.sendToAll(message);
    }

    /**
     * Send this message to everyone within a certain range of a point.
     * See {@link SimpleNetworkWrapper#sendToAllAround(IMessage, NetworkRegistry.TargetPoint)}
     */
    public static final void sendToAllAround(IMessage message, NetworkRegistry.TargetPoint point) {
        PacketDispatcher.dispatcher.sendToAllAround(message, point);
    }

    /**
     * Sends a message to everyone within a certain range of the coordinates in the same dimension.
     * Shortcut to {@link SimpleNetworkWrapper#sendToAllAround(IMessage, NetworkRegistry.TargetPoint)}
     */
    public static final void sendToAllAround(IMessage message, int dimension, double x, double y, double z, double range) {
        PacketDispatcher.sendToAllAround(message, new NetworkRegistry.TargetPoint(dimension, x, y, z, range));
    }

    /**
     * Sends a message to everyone within a certain range of the player provided.
     * Shortcut to {@link SimpleNetworkWrapper#sendToAllAround(IMessage, NetworkRegistry.TargetPoint)}
     */
    public static final void sendToAllAround(IMessage message, EntityPlayer player, double range) {
        PacketDispatcher.sendToAllAround(message, player.worldObj.provider.getDimensionId(), player.posX, player.posY, player.posZ, range);
    }

    /**
     * Send this message to everyone within the supplied dimension.
     * See {@link SimpleNetworkWrapper#sendToDimension(IMessage, int)}
     */
    public static final void sendToDimension(IMessage message, int dimensionId) {
        PacketDispatcher.dispatcher.sendToDimension(message, dimensionId);
    }

    /**
     * Send this message to the server.
     * See {@link SimpleNetworkWrapper#sendToServer(IMessage)}
     */
    public static final void sendToServer(IMessage message) {
        PacketDispatcher.dispatcher.sendToServer(message);
    }
}