public static String convertOMapToJSON(Map<?, ?> map) {
        System.out.println("DEBUG: requestJsons");
        ObjectMapper mapper = new ObjectMapper();
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte[] data;
        try {
            mapper.writeValue(out, map);
            data = out.toByteArray();
            return new String(data, "UTF-8");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }