My app has a specific requirement of uploading files as multipart using retrofit and LiveData in the background(App Navigation works while uploading data to the server.). The app requires chained network requests on the bases of the response it gets. I've used the Foreground service for network requests. this procedure works well in Android 9,10,11.
UploadFragment.kt
class UploadFragment : BaseFragment() {
....
private fun uploadFilesToServer() {
val intent = Intent(requireActivity(), MyFileUploadingService::class.java)
ContextCompat.startForegroundService(requireActivity(), intent)
}
}
FileUploadService.kt
class FileUploadService : LifecycleService() {
....
private fun registerObservers() {
viewModel?.uploadLiveData!!.observe(this) { response ->
val dataResponse: DataUploadResponse = response.responseBody!!.data!!
if (dataResponse.error == null) {
....
// Repeat
} else {
stopSelf()
}
}
}
}
I'm getting an error while observing response using LiveData.
val dataResponse: DataUploadResponse = response.responseBody!!.data!!
Error Log
2022-08-24 13:08:59.792 26140-26140/com.myapp.demo E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.myapp.demo, PID: 26140
java.lang.NullPointerException
at com.myapp.demo.service.FileUploadService$registerObservers$1.onChanged(FileUploadService.kt:242)
at com.myapp.demo.service.FileUploadService$registerObservers$1.onChanged(FileUploadService.kt:54)
at androidx.lifecycle.LiveData.considerNotify(LiveData.java:133)
at androidx.lifecycle.LiveData.dispatchingValue(LiveData.java:151)
at androidx.lifecycle.LiveData.setValue(LiveData.java:309)
at androidx.lifecycle.MutableLiveData.setValue(MutableLiveData.java:50)
at androidx.lifecycle.LiveData$1.run(LiveData.java:93)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:201)
at android.os.Looper.loop(Looper.java:288)
at android.app.ActivityThread.main(ActivityThread.java:7870)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)