Package org.springframework.web.socket.sockjs.transport.session

Class AbstractSockJsSession

java.lang.Object

org.springframework.web.socket.sockjs.transport.session.AbstractSockJsSession

All Implemented Interfaces:

Closeable, AutoCloseable, SockJsSession, WebSocketSession

Direct Known Subclasses:

AbstractHttpSockJsSession, WebSocketServerSockJsSession

public abstract class AbstractSockJsSession
extends Object
implements SockJsSession

An abstract base class for SockJS sessions implementing SockJsSession.

Since:

4.0

Author:

Rossen Stoyanchev, Sam Brannen

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DISCONNECTED_CLIENT_LOG_CATEGORY	Log category to use on network IO exceptions after a client has gone away.
protected static final Log	disconnectedClientLogger	Separate logger to use on network IO failure after a client has gone away.
protected final Log	logger
protected final Object	responseLock

Constructor Summary

Constructors

Constructor	Description
AbstractSockJsSession(String id, SockJsServiceConfig config, WebSocketHandler handler, Map<String,Object> attributes)	Create a new instance.

Method Summary

Modifier and Type	Method	Description
protected void	cancelHeartbeat()
final void	close()	Performs cleanup and notify the WebSocketHandler.
final void	close(CloseStatus status)	Performs cleanup and notify the WebSocketHandler.
final void	delegateConnectionClosed(CloseStatus status)	Invoked when the underlying connection is closed.
void	delegateConnectionEstablished()
void	delegateError(Throwable ex)
void	delegateMessages(String... messages)
void	disableHeartbeat()	Disable the SockJS heartbeat, presumably because a higher-level protocol has heartbeats enabled for the session already.
protected abstract void	disconnect(CloseStatus status)	Actually close the underlying WebSocket session or in the case of HTTP transports complete the underlying request.
Map<String,Object>	getAttributes()	Return the map with attributes associated with the WebSocket session.
String	getId()	Return a unique session identifier.
protected SockJsMessageCodec	getMessageCodec()
SockJsServiceConfig	getSockJsServiceConfig()
long	getTimeSinceLastActive()	Return the time (in ms) since the session was last active, or otherwise if the session is new, then the time since the session was created.
abstract boolean	isActive()	Polling and Streaming sessions periodically close the current HTTP request and wait for the next request to come through.
boolean	isClosed()
boolean	isNew()
boolean	isOpen()	Whether the underlying connection is open.
protected void	scheduleHeartbeat()
protected void	sendHeartbeat()
final void	sendMessage(WebSocketMessage<?> message)	Send a WebSocket message: either TextMessage or BinaryMessage.
protected abstract void	sendMessageInternal(String message)
String	toString()
void	tryCloseWithSockJsTransportError(Throwable error, CloseStatus closeStatus)	Close due to error arising from SockJS transport handling.
protected void	updateLastActiveTime()	Should be invoked whenever the session becomes inactive.
protected void	writeFrame(SockJsFrame frame)	For internal use within a TransportHandler and the (TransportHandler-specific) session class.
protected abstract void	writeFrameInternal(SockJsFrame frame)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.web.socket.WebSocketSession

getAcceptedProtocol, getBinaryMessageSizeLimit, getExtensions, getHandshakeHeaders, getLocalAddress, getPrincipal, getRemoteAddress, getTextMessageSizeLimit, getUri, setBinaryMessageSizeLimit, setTextMessageSizeLimit

Field Details

DISCONNECTED_CLIENT_LOG_CATEGORY

public static final String DISCONNECTED_CLIENT_LOG_CATEGORY

Log category to use on network IO exceptions after a client has gone away.

Servlet containers don't expose a client disconnected callback; see eclipse-ee4j/servlet-api#44. Therefore network IO failures may occur simply because a client has gone away, and that can fill the logs with unnecessary stack traces.

We make a best effort to identify such network failures, on a per-server basis, and log them under a separate log category. A simple one-line message is logged at DEBUG level, while a full stack trace is shown at TRACE level.

See Also:

• disconnectedClientLogger
• Constant Field Values

disconnectedClientLogger

protected static final Log disconnectedClientLogger

Separate logger to use on network IO failure after a client has gone away.

See Also:

• DISCONNECTED_CLIENT_LOG_CATEGORY

logger

protected final Log logger

responseLock

protected final Object responseLock

Constructor Details

AbstractSockJsSession

public AbstractSockJsSession(String id,
 SockJsServiceConfig config,
 WebSocketHandler handler,
 @Nullable
 Map<String,Object> attributes)

Create a new instance.

Parameters:

id - the session ID

config - the SockJS service configuration options

handler - the recipient of SockJS messages

attributes - the attributes from the HTTP handshake to associate with the WebSocket session; the provided attributes are copied, the original map is not used.

Method Details

getId

public String getId()

Description copied from interface: WebSocketSession

Return a unique session identifier.

Specified by:

getId in interface WebSocketSession

getMessageCodec

protected SockJsMessageCodec getMessageCodec()

getSockJsServiceConfig

public SockJsServiceConfig getSockJsServiceConfig()

getAttributes

public Map<String,Object> getAttributes()

Description copied from interface: WebSocketSession

Return the map with attributes associated with the WebSocket session.

On the server side the map can be populated initially through a HandshakeInterceptor. On the client side the map can be populated via WebSocketClient handshake methods.

Specified by:

getAttributes in interface WebSocketSession

Returns:

a Map with the session attributes (never null)

sendMessage

public final void sendMessage(WebSocketMessage<?> message)
                       throws IOException

Description copied from interface: WebSocketSession

Send a WebSocket message: either TextMessage or BinaryMessage.

Note: The underlying standard WebSocket session (JSR-356) does not allow concurrent sending. Therefore sending must be synchronized. To ensure that, one option is to wrap the WebSocketSession with the ConcurrentWebSocketSessionDecorator.

Specified by:

sendMessage in interface WebSocketSession

Throws:

IOException

See Also:

• ConcurrentWebSocketSessionDecorator

sendMessageInternal

protected abstract void sendMessageInternal(String message)
                                     throws IOException

Throws:

IOException

isNew

public boolean isNew()

isOpen

public boolean isOpen()

Description copied from interface: WebSocketSession

Whether the underlying connection is open.

Specified by:

isOpen in interface WebSocketSession

isClosed

public boolean isClosed()

close

public final void close()
                 throws IOException

Performs cleanup and notify the WebSocketHandler.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface WebSocketSession

Throws:

IOException

close

public final void close(CloseStatus status)
                 throws IOException

Performs cleanup and notify the WebSocketHandler.

Specified by:

close in interface WebSocketSession

Throws:

IOException

getTimeSinceLastActive

public long getTimeSinceLastActive()

Description copied from interface: SockJsSession

Return the time (in ms) since the session was last active, or otherwise if the session is new, then the time since the session was created.

Specified by:

getTimeSinceLastActive in interface SockJsSession

updateLastActiveTime

protected void updateLastActiveTime()

Should be invoked whenever the session becomes inactive.

disableHeartbeat

public void disableHeartbeat()

Description copied from interface: SockJsSession

Disable the SockJS heartbeat, presumably because a higher-level protocol has heartbeats enabled for the session already. It is not recommended to disable this otherwise, as it helps proxies to know the connection is not hanging.

Specified by:

disableHeartbeat in interface SockJsSession

sendHeartbeat

protected void sendHeartbeat()
                      throws SockJsTransportFailureException

Throws:

SockJsTransportFailureException

scheduleHeartbeat

protected void scheduleHeartbeat()

cancelHeartbeat

protected void cancelHeartbeat()

isActive

public abstract boolean isActive()

Polling and Streaming sessions periodically close the current HTTP request and wait for the next request to come through. During this "downtime" the session is still open but inactive and unable to send messages and therefore has to buffer them temporarily. A WebSocket session by contrast is stateful and remain active until closed.

disconnect

protected abstract void disconnect(CloseStatus status)
                            throws IOException

Actually close the underlying WebSocket session or in the case of HTTP transports complete the underlying request.

Throws:

IOException

writeFrame

protected void writeFrame(SockJsFrame frame)
                   throws SockJsTransportFailureException

For internal use within a TransportHandler and the (TransportHandler-specific) session class.

Throws:

SockJsTransportFailureException

writeFrameInternal

protected abstract void writeFrameInternal(SockJsFrame frame)
                                    throws IOException

Throws:

IOException

delegateConnectionEstablished

public void delegateConnectionEstablished()
                                   throws Exception

Throws:

Exception

delegateMessages

public void delegateMessages(String... messages)
                      throws SockJsMessageDeliveryException

Throws:

SockJsMessageDeliveryException

delegateConnectionClosed

public final void delegateConnectionClosed(CloseStatus status)
                                    throws Exception

Invoked when the underlying connection is closed.

Throws:

Exception

tryCloseWithSockJsTransportError

public void tryCloseWithSockJsTransportError(Throwable error,
 CloseStatus closeStatus)

Close due to error arising from SockJS transport handling.

delegateError

public void delegateError(Throwable ex)
                   throws Exception

Throws:

Exception

toString

public String toString()

Overrides:

toString in class Object