--- Problem:

client's request for compression is ignored.

The client sends the request for compression:

Sec-WebSocket-Extensions: permessage-deflate; client_no_context_takeover; client_max_window_bits\r\n

Webserver receives the client request,

org.springframework.web.socket.server.support.AbstractHandshakeHandler.java:

doHandshake function: try to see if requested extension is supported

String subProtocol = selectProtocol(headers.getSecWebSocketProtocol(), wsHandler);

List<WebSocketExtension> requested = headers.getSecWebSocketExtensions();

List<WebSocketExtension> supported = this.requestUpgradeStrategy.getSupportedExtensions(request);

List<WebSocketExtension> extensions = filterRequestedExtensions(request, requested, supported);

getSupportedExtensions calls into the following function, which always returns empty set for installed extensions.

io.undertow.websockets.jsr.ServerWebSocketContainer.java:

public Set<Extension> getInstalledExtensions() {

return Collections.emptySet();

}

My question is:

how to tell spring framework that the permessage-deflate extension is supported by undertow?

Environement:

Undertow 1.3.22 Final is used by springframework:

+- org.springframework.boot:spring-boot-starter-undertow:jar:1.3.5.RELEASE:compile

[INFO] | | +- io.undertow:undertow-core:jar:1.3.22.Final:compile

[INFO] | | +- io.undertow:undertow-servlet:jar:1.3.22.Final:compile

[INFO] | | +- io.undertow:undertow-websockets-jsr:jar:1.3.22.Final:compile

Thanks