org.springframework.web.socket.messaging

Interface SubProtocolHandler

All Known Implementing Classes:

StompSubProtocolHandler

public interface SubProtocolHandler

A contract for handling WebSocket messages as part of a higher level protocol, referred to as "sub-protocol" in the WebSocket RFC specification. Handles both WebSocketMessages from a client as well as Messages to a client.

Implementations of this interface can be configured on a SubProtocolWebSocketHandler which selects a sub-protocol handler to delegate messages to based on the sub-protocol requested by the client through the Sec-WebSocket-Protocol request header.

Since:

4.0

Author:

Andy Wilkinson, Rossen Stoyanchev

Method Summary

Modifier and Type	Method and Description
void	afterSessionEnded(WebSocketSession session, CloseStatus closeStatus, MessageChannel outputChannel) Invoked after a WebSocketSession has ended.
void	afterSessionStarted(WebSocketSession session, MessageChannel outputChannel) Invoked after a WebSocketSession has started.
List<String>	getSupportedProtocols() Return the list of sub-protocols supported by this handler (never null).
void	handleMessageFromClient(WebSocketSession session, WebSocketMessage<?> message, MessageChannel outputChannel) Handle the given WebSocketMessage received from a client.
void	handleMessageToClient(WebSocketSession session, Message<?> message) Handle the given Message to the client associated with the given WebSocket session.
String	resolveSessionId(Message<?> message) Resolve the session id from the given message or return null.

Method Detail

getSupportedProtocols

List<String> getSupportedProtocols()

Return the list of sub-protocols supported by this handler (never null).

handleMessageFromClient

void handleMessageFromClient(WebSocketSession session,
                             WebSocketMessage<?> message,
                             MessageChannel outputChannel)
                      throws Exception

Handle the given WebSocketMessage received from a client.

Parameters:

session - the client session

message - the client message

outputChannel - an output channel to send messages to

Throws:

Exception

handleMessageToClient

void handleMessageToClient(WebSocketSession session,
                           Message<?> message)
                    throws Exception

Handle the given Message to the client associated with the given WebSocket session.

Parameters:

session - the client session

message - the client message

Throws:

Exception

resolveSessionId

@Nullable
String resolveSessionId(Message<?> message)

Resolve the session id from the given message or return null.

Parameters:

message - the message to resolve the session id from

afterSessionStarted

void afterSessionStarted(WebSocketSession session,
                         MessageChannel outputChannel)
                  throws Exception

Invoked after a WebSocketSession has started.

Parameters:

session - the client session

outputChannel - a channel

Throws:

Exception

afterSessionEnded

void afterSessionEnded(WebSocketSession session,
                       CloseStatus closeStatus,
                       MessageChannel outputChannel)
                throws Exception

Invoked after a WebSocketSession has ended.

Parameters:

session - the client session

closeStatus - the reason why the session was closed

outputChannel - a channel

Throws:

Exception