Service vs IntentService in the Android platform
android, android-intentservice, android-service, multithreading
Solution
Tejas Lagvankar wrote a nice post about this subject. Below are some key differences between Service and IntentService.
When to use?
The Service can be used in tasks with no UI, but shouldn't be too long. If you need to perform long tasks, you must use threads within Service.
The IntentService can be used in long tasks usually with no communication to Main Thread. If communication is required, can use Main Thread handler or broadcast intents. Another case of use is when callbacks are needed (Intent triggered tasks).
How to trigger?
The Service is triggered by calling method `startService()`.
The IntentService is triggered using an Intent, it spawns a new worker thread and the method `onHandleIntent()` is called on this thread.
Triggered From
- The Service and IntentService may be triggered from any thread, activity or other application component.
Runs On
The Service runs in background but it runs on the Main Thread of the application.
The IntentService runs on a separate worker thread.
Limitations / Drawbacks
The Service may block the Main Thread of the application.
The IntentService cannot run tasks in parallel. Hence all the consecutive intents will go into the message queue for the worker thread and will execute sequentially.
When to stop?
If you implement a Service, it is your responsibility to stop the service when its work is done, by calling `stopSelf()` or `stopService()`. (If you only want to provide binding, you don't need to implement this method).
The IntentService stops the service after all start requests have been handled, so you never have to call `stopSelf()`.
Problem
I am seeking an example of something that can be done with an `IntentService` that cannot be done with a `Service` (and vice-versa)? I also believe that an `IntentService` runs in a different thread and a `Service` does not. So, as far as I can see, starting a service within its own thread is like starting an `IntentService`. Is that correct?