you need to encode json to URL and then concatenate with service URL. Also you would need to quote key with "
.
String json_to_url=URLEncoder.encode("{\"expiredAt\":{\"$gte\":\"" + getCurrentDate() + "\"}}", "utf-8");
String serviceURL=context.getString(R.string.url) + "services/promotions?limit=10&where="+ json_to_url;
Better approach would be using POST
to submit data instead GET