src/main/java/com/netiq/websockify/WebsockifyProxyHandler.java
private void sendNotModified(ChannelHandlerContext ctx) {
        HttpResponse response = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.NOT_MODIFIED);
        setDateHeader(response);

        // Close the connection as soon as the error message is sent.
        ctx.getChannel().write(response).addListener(ChannelFutureListener.CLOSE);
    }
private void sendNotModified(ChannelHandlerContext ctx) {
        HttpResponse response = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.NOT_MODIFIED);
        setDateHeader(response);

        // Close the connection as soon as the error message is sent.
        ctx.getChannel().write(response).addListener(ChannelFutureListener.CLOSE);
    }
When file timestamp is the same as what the browser is sending up, send a "304 Not Modified"

@param ctx
Context