FullHttpResponse() — netty Function Reference

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocketServerHandshaker00.java lines 126–203

    @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);
        }

        // Serve the WebSocket handshake request.
        if (!req.headers().containsValue(HttpHeaderNames.CONNECTION, HttpHeaderValues.UPGRADE, true)
                || !HttpHeaderValues.WEBSOCKET.contentEqualsIgnoreCase(req.headers().get(HttpHeaderNames.UPGRADE))) {
            throw new WebSocketServerHandshakeException("not a WebSocket handshake request: missing upgrade", req);
        }

        // Hixie 75 does not contain these headers while Hixie 76 does
        boolean isHixie76 = req.headers().contains(HttpHeaderNames.SEC_WEBSOCKET_KEY1) &&
                            req.headers().contains(HttpHeaderNames.SEC_WEBSOCKET_KEY2);

        String origin = req.headers().get(HttpHeaderNames.ORIGIN);
        //throw before allocating FullHttpResponse
        if (origin == null && !isHixie76) {
            throw new WebSocketServerHandshakeException("Missing origin header, got only " + req.headers().names(),
                                                        req);
        }

        // Create the WebSocket handshake response.
        FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, new HttpResponseStatus(101,
                isHixie76 ? "WebSocket Protocol Handshake" : "Web Socket Protocol Handshake"),
                req.content().alloc().buffer(0));
        if (headers != null) {
            res.headers().add(headers);
        }

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

        // Fill in the headers and contents depending on handshake getMethod.
        if (isHixie76) {
            // New handshake getMethod with a challenge:
            res.headers().add(HttpHeaderNames.SEC_WEBSOCKET_ORIGIN, origin);
            res.headers().add(HttpHeaderNames.SEC_WEBSOCKET_LOCATION, uri());

            String subprotocols = req.headers().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);
                }
            }

            // Calculate the answer of the challenge.
            String key1 = req.headers().get(HttpHeaderNames.SEC_WEBSOCKET_KEY1);
            String key2 = req.headers().get(HttpHeaderNames.SEC_WEBSOCKET_KEY2);
            int a = (int) (Long.parseLong(BEGINNING_DIGIT.matcher(key1).replaceAll("")) /
                           BEGINNING_SPACE.matcher(key1).replaceAll("").length());
            int b = (int) (Long.parseLong(BEGINNING_DIGIT.matcher(key2).replaceAll("")) /
                           BEGINNING_SPACE.matcher(key2).replaceAll("").length());
            long c = req.content().readLong();
            ByteBuf input = Unpooled.wrappedBuffer(new byte[16]).setIndex(0, 0);
            input.writeInt(a);
            input.writeInt(b);
            input.writeLong(c);
            res.content().writeBytes(WebSocketUtil.md5(input.array()));
        } else {
            // Old Hixie 75 handshake getMethod with no challenge:
            res.headers().add(HttpHeaderNames.WEBSOCKET_ORIGIN, origin);
            res.headers().add(HttpHeaderNames.WEBSOCKET_LOCATION, uri());

            String protocol = req.headers().get(HttpHeaderNames.WEBSOCKET_PROTOCOL);
            if (protocol != null) {
                res.headers().set(HttpHeaderNames.WEBSOCKET_PROTOCOL, selectSubprotocol(protocol));
            }
        }
        return res;
    }