// Check signature.
String previousSignature = dsParams.getSignature();
if (responseStatus == null) {
if (!StringUtils.isEmpty(previousSignature) && (data != null)
&& (JsonRenderer.getSignature(data).equals(previousSignature))) {
responseStatus = new ResponseStatus(StatusType.ERROR, ReasonType.NOT_MODIFIED, null);
} else {
responseStatus = new ResponseStatus(StatusType.OK, null, null);
}
}
StatusType statusType = responseStatus.getStatusType();
sb.append(",status:'").append(statusType.lowerCaseString()).append("'");