private static String getNamespaceId(final HttpServletRequest request) {
        String namespaceId = SYS_DEFAULT_NAMESPACE_ID;
        if (StringUtils.isNotEmpty(request.getParameter("namespaceId"))) {
            namespaceId = request.getParameter("namespaceId");
        }
        return namespaceId;
    }
get namespaceId.

@param request the request
@return the namespaceId
shenyu-admin/src/main/java/org/apache/shenyu/admin/listener/http/HttpLongPollingDataChangedListener.java