MongoDB.java

public String getMOTResultInJSON(String identifier) {
      long identifierLong;
      try {
          identifierLong = Long.valueOf(identifier);
          Bson byIdQuery = Filters.eq("vehicleid", identifierLong);
          testObj = testresults.find(byIdQuery).limit(1).first();
          if (testObj != null) {
              return testObj.toJson();
          }
      } catch (Exception e) {
          logger.error(e.getLocalizedMessage());
      }
      return "{ }"; // Not found
  }