org.springframework.web.socket.messaging

Class SubProtocolWebSocketHandler

java.lang.Object

org.springframework.web.socket.messaging.SubProtocolWebSocketHandler

All Implemented Interfaces:

Lifecycle, Phased, SmartLifecycle, MessageHandler, SubProtocolCapable, WebSocketHandler

public class SubProtocolWebSocketHandler
extends Object
implements WebSocketHandler, SubProtocolCapable, MessageHandler, SmartLifecycle

An implementation of WebSocketHandler that delegates incoming WebSocket messages to a SubProtocolHandler along with a MessageChannel to which the sub-protocol handler can send messages from WebSocket clients to the application.

Also an implementation of MessageHandler that finds the WebSocket session associated with the Message and passes it, along with the message, to the sub-protocol handler to send messages from the application back to the client.

Since:

4.0

Author:

Rossen Stoyanchev, Andy Wilkinson

Constructor Summary

Constructors

Constructor and Description
SubProtocolWebSocketHandler(MessageChannel clientInboundChannel, SubscribableChannel clientOutboundChannel)

Method Summary

Modifier and Type	Method and Description
void	addProtocolHandler(SubProtocolHandler handler) Register a sub-protocol handler.
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.
protected SubProtocolHandler	findProtocolHandler(WebSocketSession session)
SubProtocolHandler	getDefaultProtocolHandler()
int	getPhase() Return the phase value of this object.
Map<String,SubProtocolHandler>	getProtocolHandlerMap() Return the sub-protocols keyed by protocol name.
List<SubProtocolHandler>	getProtocolHandlers()
List<String>	getSubProtocols() Return all supported protocols.
void	handleMessage(Message<?> message) Handle the given message.
void	handleMessage(WebSocketSession session, WebSocketMessage<?> message) Invoked when a new WebSocket message arrives.
void	handleTransportError(WebSocketSession session, Throwable exception) Handle an error from the underlying WebSocket message transport.
boolean	isAutoStartup() Return whether this Lifecycle component should be started automatically by the container when the ApplicationContext is refreshed.
boolean	isRunning() Check whether this component is currently running.
void	setDefaultProtocolHandler(SubProtocolHandler defaultProtocolHandler) Set the SubProtocolHandler to use when the client did not request a sub-protocol.
void	setProtocolHandlers(List<SubProtocolHandler> protocolHandlers) Configure one or more handlers to use depending on the sub-protocol requested by the client in the WebSocket handshake request.
void	start() Start this component.
void	stop() Stop this component, typically in a synchronous fashion, such that the component is fully stopped upon return of this method.
void	stop(Runnable callback) Indicates that a Lifecycle component must stop if it is currently running.
boolean	supportsPartialMessages() Whether the WebSocketHandler handles partial messages.

Methods inherited from class java.lang.Object

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

Constructor Detail

SubProtocolWebSocketHandler

public SubProtocolWebSocketHandler(MessageChannel clientInboundChannel,
                                   SubscribableChannel clientOutboundChannel)

Method Detail

setProtocolHandlers

public void setProtocolHandlers(List<SubProtocolHandler> protocolHandlers)

Configure one or more handlers to use depending on the sub-protocol requested by the client in the WebSocket handshake request.

Parameters:

protocolHandlers - the sub-protocol handlers to use

getProtocolHandlers

public List<SubProtocolHandler> getProtocolHandlers()

addProtocolHandler

public void addProtocolHandler(SubProtocolHandler handler)

Register a sub-protocol handler.

getProtocolHandlerMap

public Map<String,SubProtocolHandler> getProtocolHandlerMap()

Return the sub-protocols keyed by protocol name.

setDefaultProtocolHandler

public void setDefaultProtocolHandler(SubProtocolHandler defaultProtocolHandler)

Set the SubProtocolHandler to use when the client did not request a sub-protocol.

Parameters:

defaultProtocolHandler - the default handler

getDefaultProtocolHandler

public SubProtocolHandler getDefaultProtocolHandler()

Returns:

the default sub-protocol handler to use

getSubProtocols

public List<String> getSubProtocols()

Return all supported protocols.

Specified by:

getSubProtocols in interface SubProtocolCapable

isAutoStartup

public boolean isAutoStartup()

Description copied from interface: SmartLifecycle

Return whether this Lifecycle component should be started automatically by the container when the ApplicationContext is refreshed. A value of "false" indicates that the component is intended to be started manually.

Specified by:

isAutoStartup in interface SmartLifecycle

getPhase

public int getPhase()

Description copied from interface: Phased

Return the phase value of this object.

Specified by:

getPhase in interface Phased

isRunning

public final boolean isRunning()

Description copied from interface: Lifecycle

Check whether this component is currently running.

In the case of a container, this will return true only if all components that apply are currently running.

Specified by:

isRunning in interface Lifecycle

Returns:

whether the component is currently running

start

public final void start()

Description copied from interface: Lifecycle

Start this component. Should not throw an exception if the component is already running.

In the case of a container, this will propagate the start signal to all components that apply.

Specified by:

start in interface Lifecycle

stop

public final void stop()

Description copied from interface: Lifecycle

Stop this component, typically in a synchronous fashion, such that the component is fully stopped upon return of this method. Consider implementing SmartLifecycle and its stop(Runnable) variant in cases where asynchronous stop behavior is necessary.

Should not throw an exception if the component isn't started yet.

In the case of a container, this will propagate the stop signal to all components that apply.

Specified by:

stop in interface Lifecycle

See Also:

SmartLifecycle.stop(Runnable)

stop

public final void stop(Runnable callback)

Description copied from interface: SmartLifecycle

Indicates that a Lifecycle component must stop if it is currently running.

The provided callback is used by the LifecycleProcessor to support an ordered, and potentially concurrent, shutdown of all components having a common shutdown order value. The callback must be executed after the SmartLifecycle component does indeed stop.

The LifecycleProcessor will call only this variant of the stop method; i.e. Lifecycle.stop() will not be called for SmartLifecycle implementations unless explicitly delegated to within this method.

Specified by:

stop in interface SmartLifecycle

afterConnectionEstablished

public void afterConnectionEstablished(WebSocketSession session)
                                throws Exception

Description copied from interface: WebSocketHandler

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

Specified by:

afterConnectionEstablished in interface WebSocketHandler

Throws:

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

findProtocolHandler

protected final SubProtocolHandler findProtocolHandler(WebSocketSession session)

handleMessage

public void handleMessage(WebSocketSession session,
                          WebSocketMessage<?> message)
                   throws Exception

Description copied from interface: WebSocketHandler

Invoked when a new WebSocket message arrives.

Specified by:

handleMessage in interface WebSocketHandler

Throws:

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

handleMessage

public void handleMessage(Message<?> message)
                   throws MessagingException

Description copied from interface: MessageHandler

Handle the given message.

Specified by:

handleMessage in interface MessageHandler

Parameters:

message - the message to be handled

Throws:

MessagingException

handleTransportError

public void handleTransportError(WebSocketSession session,
                                 Throwable exception)
                          throws Exception

Description copied from interface: WebSocketHandler

Handle an error from the underlying WebSocket message transport.

Specified by:

handleTransportError in interface WebSocketHandler

Throws:

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

afterConnectionClosed

public void afterConnectionClosed(WebSocketSession session,
                                  CloseStatus closeStatus)
                           throws Exception

Description copied from interface: WebSocketHandler

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.

Specified by:

afterConnectionClosed in interface WebSocketHandler

Throws:

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

supportsPartialMessages

public boolean supportsPartialMessages()

Description copied from interface: WebSocketHandler

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 WebSocketHandler.handleMessage(WebSocketSession, WebSocketMessage). The flag WebSocketMessage.isLast() indicates if the message is partial and whether it is the last part.

Specified by:

supportsPartialMessages in interface WebSocketHandler