iPhone RestKit如何加载本地JSON文件并将其映射到核心数据实体？

I'm building a two way dropbox sync app. I load objects from core data, convert them to JSON and send them over to dropbox. However, when I do sync, I compare a set of local JSON files to the dropbox JSON files. If a conflict is detected, a sync logic is applied. As a result of the sync logic, a remote JSON file may be downloaded and will replace the local JSON file.I'm building a two way dropbox sync app. I load