I m working on a codebase with both Java and Kotlin code i i

Question

I m working on a codebase with both Java and Kotlin code i introduced Kotlin coroutines to help in running background tasks however i have a function in my repository marked with the keyword suspend and i call it from an Intent Service that is written in java to sync local db with remote However i can only call a suspend function from another suspend function or a coroutine builder I three options in mind Option 1 Use GlobalScope launch <http Dispatchers IO|Dispatchers IO> on the function so that i can call it from the Intent Service However GloablScope is not highly recommended in the android context Option 2 Make my repository extend Coroutine Scope create a public function called onCleared that cancels job then call this function when the service onDestroyed method is called or when the view model onCleared method is called This option is to try and cancel any running operations Option 3 Use the viewmodel scope to launch the coroutine in the repository then call the viewmodel from the service however the viewmodel should only be limited to an activity or fragment Option 4 Refactor the intent service to Kotlin and use coroutines

marstran · Answer

You could write a non suspending wrapper function in Kotlin that runs the function in the appropriate scope That function would be easier to call from Java

marstran · Answer

If you need to return a result then the wrapper function could take a callback parameter

louiscad · Answer

IntentService is deprecated You can use WorkManager CoroutineWorker instead or just run it while the user is using your app at the foreground

bdawg.io · Answer

Option 6 Have a wrapper Kotlin function that returns a CompletableFuture using the `future ` builder

gildor · Answer

future is not somehow better than GlobalScope it s essentially the same just exposed as CompletableFuture instead of Job Deffered

gildor · Answer

Tho I agree with Louis that IntentService is not the best solution I regret every time when decided to use it and with others who voted for option 4 but I would be careful with advise to rewrite it to own coroutine based solution or use WorkingManager IntentService has very strict sequential semantics and lifecycle of service also if if it Bindable or foreground it makes it even more different But it really depends what you want to achieve If you just need fast working solution I see no problem just use GlobalScope in your case just do not do anything in launch after repository method call to avoid leak Also IntentService is a background service that runs on working thread there is nothing bad to call runBlocking inside this is how intent service intended to use block until task is done and only after that it will start processing next intent Option 2 will work but you cannot anymore use this repository from suspend functions properly and await for result it will essentially background task which is what I would try to avoid So I would rewrite only if you know what exactly you want to achieve not to solve this particular case