org.springframework.web.socket

Interface WebSocketHandler

All Known Implementing Classes:

AbstractWebSocketHandler, BinaryWebSocketHandler, ExceptionWebSocketHandlerDecorator, LoggingWebSocketHandlerDecorator, PerConnectionWebSocketHandler, SockJsWebSocketHandler, SubProtocolWebSocketHandler, TextWebSocketHandler, WebSocketHandlerDecorator

public interface WebSocketHandler

A handler for WebSocket messages and lifecycle events.

Implementations of this interface are encouraged to handle exceptions locally where it makes sense or alternatively let the exception bubble up in which case by default the exception is logged and the session closed with SERVER_ERROR(1011). The exception handling strategy is provided by ExceptionWebSocketHandlerDecorator and it can be customized or replaced by decorating the WebSocketHandler with a different decorator.

Since:

4.0

Author:

Rossen Stoyanchev, Phillip Webb

Method Summary

Modifier and Type	Method and Description
void	afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) Invoked after the WebSocket connection has been closed by either side, or after a transport error has occurred.
void	afterConnectionEstablished(WebSocketSession session) Invoked after WebSocket negotiation has succeeded and the WebSocket connection is opened and ready for use.
void	handleMessage(WebSocketSession session, WebSocketMessage<?> message) Invoked when a new WebSocket message arrives.
void	handleTransportError(WebSocketSession session, java.lang.Throwable exception) Handle an error from the underlying WebSocket message transport.
boolean	supportsPartialMessages() Whether the WebSocketHandler handles partial messages.

Method Detail

afterConnectionEstablished

void afterConnectionEstablished(WebSocketSession session)
                         throws java.lang.Exception

Invoked after WebSocket negotiation has succeeded and the WebSocket connection is opened and ready for use.

Throws:

java.lang.Exception - this method can handle or propagate exceptions; see class-level Javadoc for details.

handleMessage

void handleMessage(WebSocketSession session,
                   WebSocketMessage<?> message)
            throws java.lang.Exception

Invoked when a new WebSocket message arrives.

Throws:

java.lang.Exception - this method can handle or propagate exceptions; see class-level Javadoc for details.

handleTransportError

void handleTransportError(WebSocketSession session,
                          java.lang.Throwable exception)
                   throws java.lang.Exception

Handle an error from the underlying WebSocket message transport.

Throws:

java.lang.Exception - this method can handle or propagate exceptions; see class-level Javadoc for details.

afterConnectionClosed

void afterConnectionClosed(WebSocketSession session,
                           CloseStatus closeStatus)
                    throws java.lang.Exception

Invoked after the WebSocket connection has been closed by either side, or after a transport error has occurred. Although the session may technically still be open, depending on the underlying implementation, sending messages at this point is discouraged and most likely will not succeed.

Throws:

java.lang.Exception - this method can handle or propagate exceptions; see class-level Javadoc for details.

supportsPartialMessages

boolean supportsPartialMessages()

Whether the WebSocketHandler handles partial messages. If this flag is set to true and the underlying WebSocket server supports partial messages, then a large WebSocket message, or one of an unknown size may be split and maybe received over multiple calls to handleMessage(WebSocketSession, WebSocketMessage). The flag WebSocketMessage.isLast() indicates if the message is partial and whether it is the last part.