Package net.fabricmc.fabric.api.networking.v1

Class ServerPlayNetworking

java.lang.Object

net.fabricmc.fabric.api.networking.v1.ServerPlayNetworking

public final class ServerPlayNetworking
extends Object

Offers access to play stage server-side networking functionalities.

Server-side networking functionalities include receiving serverbound packets, sending clientbound packets, and events related to server-side network handlers.

This class should be only used for the logical server.

Packet object-based API

This class provides a classic registration method, registerGlobalReceiver(Identifier, PlayChannelHandler), and a newer method utilizing packet objects, registerGlobalReceiver(PacketType, PlayPacketHandler). For most mods, using the newer method will improve the readability of the code by separating packet reading/writing code to a separate class. Additionally, the newer method executes the callback in the server thread, ensuring thread safety. For this reason using the newer method is highly recommended. The two methods are network-compatible with each other, so long as the buffer contents are read and written in the same order.

The newer, packet object-based API involves three classes:

• A class implementing FabricPacket that is "sent" over the network
• PacketType instance, which represents the packet's type (and its channel)
• ServerPlayNetworking.PlayPacketHandler, which handles the packet (usually implemented as a functional interface)

See the documentation on each class for more information.

See Also:

• ServerLoginNetworking

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ServerPlayNetworking.PlayChannelHandler
static interface	ServerPlayNetworking.PlayPacketHandler<T extends FabricPacket>	A thread-safe packet handler utilizing FabricPacket.

Method Summary

Modifier and Type	Method	Description
static boolean	canSend(ServerPlayerEntity player, PacketType<?> type)	Checks if the connected client declared the ability to receive a specific type of packet.
static boolean	canSend(ServerPlayerEntity player, Identifier channelName)	Checks if the connected client declared the ability to receive a packet on a specified channel name.
static boolean	canSend(ServerPlayNetworkHandler handler, PacketType<?> type)	Checks if the connected client declared the ability to receive a specific type of packet.
static boolean	canSend(ServerPlayNetworkHandler handler, Identifier channelName)	Checks if the connected client declared the ability to receive a packet on a specified channel name.
static Packet<ClientPlayPacketListener>	createS2CPacket(Identifier channelName, PacketByteBuf buf)	Creates a packet which may be sent to a connected client.
static Set<Identifier>	getGlobalReceivers()	Gets all channel names which global receivers are registered for.
static Set<Identifier>	getReceived(ServerPlayerEntity player)	Gets all the channel names that the server can receive packets on.
static Set<Identifier>	getReceived(ServerPlayNetworkHandler handler)	Gets all the channel names that the server can receive packets on.
static Set<Identifier>	getSendable(ServerPlayerEntity player)	Gets all channel names that the connected client declared the ability to receive a packets on.
static Set<Identifier>	getSendable(ServerPlayNetworkHandler handler)	Gets all channel names that a connected client declared the ability to receive a packets on.
static PacketSender	getSender(ServerPlayerEntity player)	Gets the packet sender which sends packets to the connected client.
static PacketSender	getSender(ServerPlayNetworkHandler handler)	Gets the packet sender which sends packets to the connected client.
static MinecraftServer	getServer(ServerPlayNetworkHandler handler)	Returns the Minecraft Server of a server play network handler.
static <T extends FabricPacket> boolean	registerGlobalReceiver(PacketType<T> type, ServerPlayNetworking.PlayPacketHandler<T> handler)	Registers a handler for a packet type.
static boolean	registerGlobalReceiver(Identifier channelName, ServerPlayNetworking.PlayChannelHandler channelHandler)	Registers a handler to a channel.
static <T extends FabricPacket> boolean	registerReceiver(ServerPlayNetworkHandler networkHandler, PacketType<T> type, ServerPlayNetworking.PlayPacketHandler<T> handler)	Registers a handler for a packet type.
static boolean	registerReceiver(ServerPlayNetworkHandler networkHandler, Identifier channelName, ServerPlayNetworking.PlayChannelHandler channelHandler)	Registers a handler to a channel.
static void	send(ServerPlayerEntity player, Identifier channelName, PacketByteBuf buf)	Sends a packet to a player.
static <T extends FabricPacket> void	send(ServerPlayerEntity player, T packet)	Sends a packet to a player.
static <T extends FabricPacket> @Nullable ServerPlayNetworking.PlayPacketHandler<T>	unregisterGlobalReceiver(PacketType<T> type)	Removes the handler for a packet type.
static @Nullable ServerPlayNetworking.PlayChannelHandler	unregisterGlobalReceiver(Identifier channelName)	Removes the handler of a channel.
static <T extends FabricPacket> @Nullable ServerPlayNetworking.PlayPacketHandler<T>	unregisterReceiver(ServerPlayNetworkHandler networkHandler, PacketType<T> type)	Removes the handler for a packet type.
static @Nullable ServerPlayNetworking.PlayChannelHandler	unregisterReceiver(ServerPlayNetworkHandler networkHandler, Identifier channelName)	Removes the handler of a channel.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

registerGlobalReceiver

public static boolean registerGlobalReceiver(Identifier channelName,
 ServerPlayNetworking.PlayChannelHandler channelHandler)

Registers a handler to a channel. A global receiver is registered to all connections, in the present and future.

The handler runs on the network thread. After reading the buffer there, the world must be modified in the server thread by calling ThreadExecutor.execute(Runnable).

If a handler is already registered to the channel, this method will return false, and no change will be made. Use unregisterReceiver(ServerPlayNetworkHandler, Identifier) to unregister the existing handler.

For new code, registerGlobalReceiver(PacketType, PlayPacketHandler) is preferred, as it is designed in a way that prevents thread safety issues.

Parameters:

channelName - the id of the channel

channelHandler - the handler

Returns:

false if a handler is already registered to the channel

See Also:

• unregisterGlobalReceiver(Identifier)
• registerReceiver(ServerPlayNetworkHandler, Identifier, PlayChannelHandler)

registerGlobalReceiver

public static <T extends FabricPacket> boolean registerGlobalReceiver(PacketType<T> type,
 ServerPlayNetworking.PlayPacketHandler<T> handler)

Registers a handler for a packet type. A global receiver is registered to all connections, in the present and future.

If a handler is already registered for the type, this method will return false, and no change will be made. Use unregisterReceiver(ServerPlayNetworkHandler, PacketType) to unregister the existing handler.

Parameters:

type - the packet type

handler - the handler

Returns:

false if a handler is already registered to the channel

See Also:

• unregisterGlobalReceiver(PacketType)
• registerReceiver(ServerPlayNetworkHandler, PacketType, PlayPacketHandler)

unregisterGlobalReceiver

@Nullable
public static @Nullable ServerPlayNetworking.PlayChannelHandler unregisterGlobalReceiver(Identifier channelName)

Removes the handler of a channel. A global receiver is registered to all connections, in the present and future.

The channel is guaranteed not to have a handler after this call.

Parameters:

channelName - the id of the channel

Returns:

the previous handler, or null if no handler was bound to the channel

See Also:

• registerGlobalReceiver(Identifier, PlayChannelHandler)
• unregisterReceiver(ServerPlayNetworkHandler, Identifier)

unregisterGlobalReceiver

@Nullable
public static <T extends FabricPacket>
@Nullable ServerPlayNetworking.PlayPacketHandler<T> unregisterGlobalReceiver(PacketType<T> type)

Removes the handler for a packet type. A global receiver is registered to all connections, in the present and future.

The type is guaranteed not to have an associated handler after this call.

Parameters:

type - the packet type

Returns:

the previous handler, or null if no handler was bound to the channel, or it was not registered using registerGlobalReceiver(PacketType, PlayPacketHandler)

See Also:

• registerGlobalReceiver(PacketType, PlayPacketHandler)
• unregisterReceiver(ServerPlayNetworkHandler, PacketType)

getGlobalReceivers

public static Set<Identifier> getGlobalReceivers()

Gets all channel names which global receivers are registered for. A global receiver is registered to all connections, in the present and future.

Returns:

all channel names which global receivers are registered for.

registerReceiver

public static boolean registerReceiver(ServerPlayNetworkHandler networkHandler,
 Identifier channelName,
 ServerPlayNetworking.PlayChannelHandler channelHandler)

Registers a handler to a channel. This method differs from registerGlobalReceiver(Identifier, PlayChannelHandler) since the channel handler will only be applied to the player represented by the ServerPlayNetworkHandler.

The handler runs on the network thread. After reading the buffer there, the world must be modified in the server thread by calling ThreadExecutor.execute(Runnable).

For example, if you only register a receiver using this method when a ServerLoginNetworking.registerGlobalReceiver(Identifier, ServerLoginNetworking.LoginQueryResponseHandler) login response has been received, you should use ServerPlayConnectionEvents.INIT to register the channel handler.

If a handler is already registered to the channelName, this method will return false, and no change will be made. Use unregisterReceiver(ServerPlayNetworkHandler, Identifier) to unregister the existing handler.

For new code, registerReceiver(ServerPlayNetworkHandler, PacketType, PlayPacketHandler) is preferred, as it is designed in a way that prevents thread safety issues.

Parameters:

networkHandler - the handler

channelName - the id of the channel

channelHandler - the handler

Returns:

false if a handler is already registered to the channel name

See Also:

• ServerPlayConnectionEvents.INIT

registerReceiver

public static <T extends FabricPacket> boolean registerReceiver(ServerPlayNetworkHandler networkHandler,
 PacketType<T> type,
 ServerPlayNetworking.PlayPacketHandler<T> handler)

Registers a handler for a packet type. This method differs from registerGlobalReceiver(PacketType, PlayPacketHandler) since the channel handler will only be applied to the player represented by the ServerPlayNetworkHandler.

For example, if you only register a receiver using this method when a ServerLoginNetworking.registerGlobalReceiver(Identifier, ServerLoginNetworking.LoginQueryResponseHandler) login response has been received, you should use ServerPlayConnectionEvents.INIT to register the channel handler.

If a handler is already registered for the type, this method will return false, and no change will be made. Use unregisterReceiver(ServerPlayNetworkHandler, PacketType) to unregister the existing handler.

Parameters:

networkHandler - the network handler

type - the packet type

handler - the handler

Returns:

false if a handler is already registered to the channel name

See Also:

• ServerPlayConnectionEvents.INIT

unregisterReceiver

@Nullable
public static @Nullable ServerPlayNetworking.PlayChannelHandler unregisterReceiver(ServerPlayNetworkHandler networkHandler,
 Identifier channelName)

Removes the handler of a channel.

The channelName is guaranteed not to have a handler after this call.

Parameters:

channelName - the id of the channel

Returns:

the previous handler, or null if no handler was bound to the channel name

unregisterReceiver

@Nullable
public static <T extends FabricPacket>
@Nullable ServerPlayNetworking.PlayPacketHandler<T> unregisterReceiver(ServerPlayNetworkHandler networkHandler,
 PacketType<T> type)

Removes the handler for a packet type.

The type is guaranteed not to have an associated handler after this call.

Parameters:

type - the type of the packet

Returns:

the previous handler, or null if no handler was bound to the channel, or it was not registered using registerReceiver(ServerPlayNetworkHandler, PacketType, PlayPacketHandler)

getReceived

public static Set<Identifier> getReceived(ServerPlayerEntity player)

Gets all the channel names that the server can receive packets on.

Parameters:

player - the player

Returns:

All the channel names that the server can receive packets on

getReceived

public static Set<Identifier> getReceived(ServerPlayNetworkHandler handler)

Gets all the channel names that the server can receive packets on.

Parameters:

handler - the network handler

Returns:

All the channel names that the server can receive packets on

getSendable

public static Set<Identifier> getSendable(ServerPlayerEntity player)

Gets all channel names that the connected client declared the ability to receive a packets on.

Parameters:

player - the player

Returns:

All the channel names the connected client declared the ability to receive a packets on

getSendable

public static Set<Identifier> getSendable(ServerPlayNetworkHandler handler)

Gets all channel names that a connected client declared the ability to receive a packets on.

Parameters:

handler - the network handler

Returns:

true if the connected client has declared the ability to receive a packet on the specified channel

canSend

public static boolean canSend(ServerPlayerEntity player,
 Identifier channelName)

Checks if the connected client declared the ability to receive a packet on a specified channel name.

Parameters:

player - the player

channelName - the channel name

Returns:

true if the connected client has declared the ability to receive a packet on the specified channel

canSend

public static boolean canSend(ServerPlayerEntity player,
 PacketType<?> type)

Checks if the connected client declared the ability to receive a specific type of packet.

Parameters:

player - the player

type - the packet type

Returns:

true if the connected client has declared the ability to receive a specific type of packet

canSend

public static boolean canSend(ServerPlayNetworkHandler handler,
 Identifier channelName)

Checks if the connected client declared the ability to receive a packet on a specified channel name.

Parameters:

handler - the network handler

channelName - the channel name

Returns:

true if the connected client has declared the ability to receive a packet on the specified channel

canSend

public static boolean canSend(ServerPlayNetworkHandler handler,
 PacketType<?> type)

Checks if the connected client declared the ability to receive a specific type of packet.

Parameters:

handler - the network handler

type - the packet type

Returns:

true if the connected client has declared the ability to receive a specific type of packet

createS2CPacket

public static Packet<ClientPlayPacketListener> createS2CPacket(Identifier channelName,
 PacketByteBuf buf)

Creates a packet which may be sent to a connected client.

Parameters:

channelName - the channel name

buf - the packet byte buf which represents the payload of the packet

Returns:

a new packet

getSender

public static PacketSender getSender(ServerPlayerEntity player)

Gets the packet sender which sends packets to the connected client.

Parameters:

player - the player

Returns:

the packet sender

getSender

public static PacketSender getSender(ServerPlayNetworkHandler handler)

Gets the packet sender which sends packets to the connected client.

Parameters:

handler - the network handler, representing the connection to the player/client

Returns:

the packet sender

send

public static void send(ServerPlayerEntity player,
 Identifier channelName,
 PacketByteBuf buf)

Sends a packet to a player.

Parameters:

player - the player to send the packet to

channelName - the channel of the packet

buf - the payload of the packet.

send

public static <T extends FabricPacket> void send(ServerPlayerEntity player,
 T packet)

Sends a packet to a player.

Parameters:

player - the player to send the packet to

packet - the packet

getServer

public static MinecraftServer getServer(ServerPlayNetworkHandler handler)

Returns the Minecraft Server of a server play network handler.

Parameters:

handler - the server play network handler