Synchronization with ASyncTask on android

I am thinking about implementation of synchronization in my android application with ASyncTask and AlarmManager. Tried to do the same with SyncAdapter, but it just complicates the process and has other disadvantages (ContentProvider is needed, manual sync seems to be impossible if automated is disabled, user is needed etc.).

So, the question I have now with ASyncTask - let's say, it is started every 24 hours. But in case if there is not internet connection at this time, synchronization will not happen开发者_如何学C. Next time attempt will happen after 24 hours again. What can I do to avoid this? I.e. if 24 hours are already passed, then any time internet connection appeared, the task should be run. After this moment next 24 hours to be counted. For ex.,

sync 1 - day 1 12:00 (successful)
sync 2 - day 2 12:00 (failed - no internet connection)
sync 3 - day 2 20:00 (successful, internet connection appeared)
sync 4 - day 3 20:00 (successful)

Believe, I can either run my task more often (for ex., each 30 minutes) and store time of last update somewhere. Or, I can listen for event when internet connection appears. What is the best approach? Or, is there some standard functionality for the same?

I would go with the BroadcastListener registered to do the syncing when internet connection is available. You could use the SharedPreferences to indicate for this listener, that sync is needed - because I guess you'd have to register this listener in the manifest, I think there's no way to handle this dynamically.

This way you can be sure that sync will happen if there's net connection available, while the 30-min-polling might miss the chance.