FullHttpResponse() — netty Function Reference

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocketServerHandshaker13.java lines 137–191

    @Override
    protected FullHttpResponse newHandshakeResponse(FullHttpRequest req, HttpHeaders headers) {
        HttpMethod method = req.method();
        if (!GET.equals(method)) {
            throw new WebSocketServerHandshakeException("Invalid WebSocket handshake method: " + method, req);
        }

        HttpHeaders reqHeaders = req.headers();
        if (!reqHeaders.contains(HttpHeaderNames.CONNECTION) ||
            !reqHeaders.containsValue(HttpHeaderNames.CONNECTION, HttpHeaderValues.UPGRADE, true)) {
            throw new WebSocketServerHandshakeException(
                    "not a WebSocket request: a |Connection| header must includes a token 'Upgrade'", req);
        }

        if (!reqHeaders.contains(HttpHeaderNames.UPGRADE, HttpHeaderValues.WEBSOCKET, true)) {
            throw new WebSocketServerHandshakeException(
                    "not a WebSocket request: a |Upgrade| header must containing the value 'websocket'", req);
        }

        CharSequence key = reqHeaders.get(HttpHeaderNames.SEC_WEBSOCKET_KEY);
        if (key == null) {
            throw new WebSocketServerHandshakeException("not a WebSocket request: missing key", req);
        }

        FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, HttpResponseStatus.SWITCHING_PROTOCOLS,
                req.content().alloc().buffer(0));
        if (headers != null) {
            res.headers().add(headers);
        }

        String acceptSeed = key + WEBSOCKET_13_ACCEPT_GUID;
        byte[] sha1 = WebSocketUtil.sha1(acceptSeed.getBytes(CharsetUtil.US_ASCII));
        String accept = WebSocketUtil.base64(sha1);

        if (logger.isDebugEnabled()) {
            logger.debug("WebSocket version 13 server handshake key: {}, response: {}", key, accept);
        }

        res.headers().set(HttpHeaderNames.UPGRADE, HttpHeaderValues.WEBSOCKET)
                     .set(HttpHeaderNames.CONNECTION, HttpHeaderValues.UPGRADE)
                     .set(HttpHeaderNames.SEC_WEBSOCKET_ACCEPT, accept);

        String subprotocols = reqHeaders.get(HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL);
        if (subprotocols != null) {
            String selectedSubprotocol = selectSubprotocol(subprotocols);
            if (selectedSubprotocol == null) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Requested subprotocol(s) not supported: {}", subprotocols);
                }
            } else {
                res.headers().set(HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL, selectedSubprotocol);
            }
        }
        return res;
    }