What is the best pattern to follow on android for accessing internal storage being used as cache?

In Android, I've used DiskLruCache before and have always performed operations with it through services (to avoid accessing disk/cache on the UI thread). I've also used sql database for storing/accessing data for my applications and have used Loaders. I'm wondering when you would use a service vs a loader to read/write from cache and if there are any other better patterns to follow?