protected final SubProtocolHandler findProtocolHandler(WebSocketSession session) {
String protocol = null;
try {
protocol = session.getAcceptedProtocol();
} catch (Exception ex) {
// Shouldn't happen
logger.error(
"Failed to obtain session.getAcceptedProtocol(). Will use the "
+ "default protocol handler (if configured).",
ex);
}
SubProtocolHandler handler;
if (!StringUtils.isEmpty(protocol)) {
handler = this.protocolHandlerLookup.get(protocol);
Assert.state(
handler != null, "No handler for '" + protocol + "' among " + this.protocolHandlerLookup);
} else {
if (this.defaultProtocolHandler != null) {
handler = this.defaultProtocolHandler;
} else if (this.protocolHandlers.size() == 1) {
handler = this.protocolHandlers.iterator().next();
} else {
throw new IllegalStateException(
"Multiple protocol handlers configured and "
+ "no protocol was negotiated. Consider configuring a default SubProtocolHandler.");
}
}
return handler;
}
