Question

i want to keep my app in sync with the Server. The communication between client (android app) and server is handled through JSON Objects / HTTP. What is the best strategy if the connection is not available anymore? It is important that the user can continue his work with the app. Does there even exist frameworks for such sync-problems?

i thought about a queue of transactions?! Any reccomendations or experiences?

Thanks

Answer 1

For fetching… I once wrote a caching URL manager that would load read the JSON from reply from the server and write it to the SD Card. When if the user did another request for the same URL a short time later, the URL manager would simply return the cached json from the filesystem as the JSON reply. This made the communication code somewhat transparent, in that I was always dealing with JSON replies, whether or not they were cached or real time.

For sending information to the server, you could write all information to the database, and use a background service that pushes the data to the server. That way the UI will always succeed in writing the information and your sync service would push data if there was a network connection. Using a Service you can simply pass the data in the Service intent and it can worry about the writing to db and syncing, etc.