/** Handle an outbound Spring Message to a WebSocket client. */
@Override
public void handleMessage(Message<?> message) throws MessagingException {
String sessionId = resolveSessionId(message);
if (sessionId == null) {
logger.error("Couldn't find sessionId in " + message);
return;
}
WebSocketSessionHolder holder = this.sessions.get(sessionId);
if (holder == null) {
if (logger.isDebugEnabled()) {
// The broker may not have removed the session yet
logger.debug("No session for " + message);
}
return;
}
WebSocketSession session = holder.getSession();
try {
findProtocolHandler(session).handleMessageToClient(session, message);
} catch (SessionLimitExceededException ex) {
try {
if (logger.isDebugEnabled()) {
logger.debug("Terminating '" + session + "'", ex);
}
this.stats.incrementLimitExceededCount();
clearSession(session, ex.getStatus()); // clear first, session may be unresponsive
session.close(ex.getStatus());
} catch (Exception secondException) {
logger.debug("Failure while closing session " + sessionId + ".", secondException);
}
} catch (Exception e) {
// Could be part of normal workflow (e.g. browser tab closed)
logger.debug("Failed to send message to client in " + session + ": " + message, e);
}
}
/**
* When a session is connected through a higher-level protocol it has a chance
* to use heartbeat management to shut down sessions that are too slow to send
* or receive messages. However, after a WebSocketSession is established and
* before the higher level protocol is fully connected there is a possibility
* for sessions to hang. This method checks and closes any sessions that have
* been connected for more than 60 seconds without having received a single
* message.
*/
private void checkSessions() throws IOException {
long currentTime = System.currentTimeMillis();
if (!isRunning() || (currentTime - this.lastSessionCheckTime < TIME_TO_FIRST_MESSAGE)) {
return;
}
if (this.sessionCheckLock.tryLock()) {
try {
for (WebSocketSessionHolder holder : this.sessions.values()) {
if (holder.hasHandledMessages()) {
continue;
}
long timeSinceCreated = currentTime - holder.getCreateTime();
if (timeSinceCreated < TIME_TO_FIRST_MESSAGE) {
continue;
}
WebSocketSession session = holder.getSession();
if (logger.isErrorEnabled()) {
logger.error("No messages received after " + timeSinceCreated + " ms. " +
"Closing " + holder.getSession() + ".");
}
try {
this.stats.incrementNoMessagesReceivedCount();
session.close(CloseStatus.SESSION_NOT_RELIABLE);
}
catch (Throwable t) {
logger.error("Failure while closing " + session, t);
}
}
}
finally {
this.sessionCheckLock.unlock();
}
}
}
/**
* Handle an inbound message from a WebSocket client.
*/
@Override
public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {
WebSocketSessionHolder holder = this.sessions.get(session.getId());
if (holder != null) {
session = holder.getSession();
}
SubProtocolHandler protocolHandler = findProtocolHandler(session);
protocolHandler.handleMessageFromClient(session, message, this.clientInboundChannel);
if (holder != null) {
holder.setHasHandledMessages();
}
checkSessions();
}
@Override
public final void stop() {
synchronized (this.lifecycleMonitor) {
this.running = false;
this.clientOutboundChannel.unsubscribe(this);
for (WebSocketSessionHolder holder : this.sessions.values()) {
try {
holder.getSession().close(CloseStatus.GOING_AWAY);
} catch (Throwable t) {
logger.error("Failed to close '" + holder.getSession() + "': " + t.getMessage());
}
}
}
}
