Entity Mapper

    /**
     * Convert Google Datastore Entity into Json String. Each serialization failure results in
     * dispatch of error status and message to user.
     * @param   entity  The Google Datastore Entity to be serialized
     * @return  String  Json string representation of the entity
     */
    protected String toEntityMapString(Entity entity){
        String result = "";

        try{
            result = new ObjectMapper().writeValueAsString(entity.getProperties());
        }catch(JsonMappingException e){
            e.printStackTrace();
            databaseListener.OnQueryFinished("{\"status\":\"error\",message:\"Entity mapping failed (at com.artlogic.defaultserver.db.DBUser:toEntityMapString)\"}");
        } catch (JsonGenerationException e) {
            e.printStackTrace();
            databaseListener.OnQueryFinished("{\"status\":\"error\",message:\"Json string generation failed (at com.artlogic.defaultserver.db.DBUser:toEntityMapString)\"}");
        } catch (IOException e) {
            e.printStackTrace();
            databaseListener.OnQueryFinished("{\"status\":\"error\",message:\"IO exception raised (at com.artlogic.defaultserver.db.DBUser:toEntityMapString)\"}");
        }

        return result;
    }