Creating a Sync Adapter
The sync adapter component in your app encapsulates the code for the tasks that transfer data between the device and a server. Based on the scheduling and triggers you provide in your app, the sync adapter framework runs the code in the sync adapter component. To add a sync adapter component to your app, you need to add the following pieces:
Sync adapter class.
A class that wraps your data transfer code in an interface compatible with the sync adapter framework.
Bound Service.
A component that allows the sync adapter framework to run the code in your sync adapter class.
Sync adapter XML metadata file.
A file containing information about your sync adapter. The framework reads this file to find out how to load and schedule your data transfer.
Declarations in the app manifest.
XML that declares the bound service and points to sync adapter-specific metadata.
This lesson shows you how to define these elements
Create a Sync Adapter Class
https://developer.android.com/training/sync-adapters/creating-sync-adapter.html#CreateSyncAdapter