if (soLog.isDebugEnabled()) soLog.debug("Looking up authority by ID.");
descriptor = moServer.lookupById(authorityId, segment, bSigned);
}
if (descriptor == null) throw new ServerNotFoundException("Null descriptor returned.");
} catch(ServerNotFoundException ex) {
soLog.warn("Got no descriptor from server.", ex);
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;