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What are differences between JobIntentService and IntentService?

I do not understand what difference between those two APIs. I mean when to use the first one. Why is there JobIntentService ?
Thanks in advance

I would recommend to read this article explaining about the difference between intent service and job intent service. When we look for the first time at these terms Service, IntentService, JobIntentService they would look almost similar - in one way or other they would perform some operations in background (which user does not notice). But there is few difference in the way they operate,
Service - This runs on the same main thread which invokes this service and performs some background operation. For any long running operation happening on the main thread it is recommended to create a new thread and do the job (eg; Handler) by not impacting the main thread's performance.
Drawback : Runs on main thread
IntentService - Intent service also helps in doing some long running (indefinite) background task. The only difference is that it creates a new thread to perform this task and does not run on the main thread. Does the given job on it's onHandleIntent.
Drawback: The job given to the IntentService would get lost when the application is killed
JobIntentService - Job intent service is very similar to IntentService but with few benefits like the application can kill this job at any time and it can start the job from the beginning once the application gets recreated/up.
But from Oreo, if the app is running in background it's not allowed to start the service in background. Android asks us to start the service explicitly by context.startForegroundService instead of context.startService and when the service is started within 5 seconds it must be tied to the notification to have a UI element associated with it.
Reference : https://developer.android.com/about/versions/oreo/background.html

Both work same but the only difference with JobIntentService is that JobIntentService gets restarted if the application gets killed while the service was executing. OnHandleWork() get's restarted after the application get's killed.

Basically, the two follow the same role, the difference being that an IntentService it is a base class for Service that handles an explicit asynchronous request with Intent on demand, it is starts through the startService (passing the Intent of the service), from hence the service is started as you wish, from the Android Oreo JobIntentService it also performs work processing however it is able to keep running in older versions, it also makes a process simpler. More in fact the 2 APIs have the same follow up. For the Execution of the work from the Oreo uses if JobScheduler.enqueue already in the older versions of the platform, it will be used Context.startService
Hope this helps.

Android service and native threads

Given the limitations that are being imposed on background services in later versions of Android, how do you accomplish the following:
The application's JAVA background service and the native C++ threads which are started by the JAVA background service via JNI continue to run regardless of the phone's state (screen on or off) and regardless of the application's state (activity life cycle). If an activity has been destroyed, the background service must continue to run.
If the user clears the application from the task list (menu button), the background service continues to run and so does the C++ threads.
If the user presses the menu back button, the background service continues to run and so does the C++ threads.
If the user navigates to the OS settings (applications) and selects FORCE CLOSE/STOP for the application, then the application AND the background service is stopped/destroyed.
One of the native threads is responsible for listening and processing UDP data via a socket that listens for multicast data. It is critical that this continues to work regardless of phone/app state (unless the app is forcefully closed).

Not sure if I get your problem right, but all these points you mention, one can accomplish by using the Android Service Component like describede here: https://developer.android.com/guide/components/services.html
I worked with this some time ago and it did just these points you require.
Please correct me if I'm wrong.

How to kill a Service [duplicate]

I am developing an application in which a background service is created to collect sensor data. I am starting the service from my activity:
startService(new Intent(this, MyService.class));
I created the service so if the application is destroyed, the background service still continues to collect data. I tried this, and it worked to a certain extent. My problem is that when I kill the application, the service seems to restart because the onCreate() service and the onStart() methods are invoked. Is there any way with which the service isn't restarted please?
UPDATE:
As suggested in an answer below, I added the following method in the service but no luck.
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_NOT_STICKY;
}

It depends on the value returned in onStartCommand.
You must return START_NOT_STICKY
According to the documentation:
For started services, there are two additional major modes of operation they can decide to run in, depending on the value they return from onStartCommand(): START_STICKY is used for services that are explicitly started and stopped as needed, while START_NOT_STICKY or START_REDELIVER_INTENT are used for services that should only remain running while processing any commands sent to them
In short:
If you return START_STICKY the service gets recreated whenever the resources are available. If you return START_NOT_STICKY you have to re-activate the service sending a new intent.
Since all of this triggered my curiosity, I made a sample app to test this. You can find the zip with all the sources here
There are a startService button and a stopService button that do what you would expect from them.
The service returns START_NOT_STICKY in onStartCommand.
I placed toasts in onCreate, onStartCommand and onDestroy.
Here what happens:
If I press start, onCreate and onStart are called
If I press stop, onDestroy is triggered
If I press start twice, onCreate is called once and onStartCommand twice
So it behaves as one would expect.
If I start the service and kill the app as you described, onDestroy does not get called but neither onCreate or onStart.
If I get back to the app and I press start again, onCreate gets called which means that, as I wrote before, START_NOT_STICKY prevents the service to getting restarted automatically.
I guess you have something else in your app that starts the service again (maybe a pending intent).

The app and the service live on the same process, which means when the app is killed so is your service. Changing the return value of onStartCommand doesn't affect this process. It simply tells the Service to either start/stop when you tell it or when it's finished doing what it needs to. As mentioned in your comment to your original post, setting it as a foreground process worked, but that's really just forcing the service to have a high priority, not solving the problem.
To change the Service so that it's killed separately and assuming it's a started service rather than a bound service due to the use of onStartCommand, specify a process name in the manifest for that Service.
From the Process and Threads Developer Guide:
The manifest entry for each type of component element— <activity>, <service>, <receiver>, and <provider>—
supports an android:process attribute that can specify a
process in which that component should run. You can set
this
attribute so that each component runs in its own process or so
that some components share a process while
others do not. You can also set android:process so that
components of different applications run in the same
process—provided that the applications share the same
Linux user ID and are signed with the same certificates.
Android might decide to shut down a process at some
point, when memory is low and required by other
processes that are more immediately serving the user.
Application components running in the process that's
killed are consequently destroyed. A process is started
again for those components when there's again work for them to do.
From <service> in Manifest File:
android:process
The name of the process where the service is to run.
Normally, all components of an application run in the default process
created for the application. It has the same name as the application
package. The element's process attribute can set a
different default for all components. But component can override the
default with its own process attribute, allowing you to spread your
application across multiple processes.
If the name assigned to this
attribute begins with a colon (':'), a new process, private to the
application, is created when it's needed and the service runs in that
process. If the process name begins with a lowercase character, the
service will run in a global process of that name, provided that it
has permission to do so. This allows components in different
applications to share a process, reducing resource usage.
Not sure why the other answer that mentioned this was down voted. I've used this method in the past and, today, created a simple one Activity app with a Service on a different process just to make sure I wasn't crazy. I used Android Device Monitor to kill the app's process. You can see both, separate processes in ADM and can see that when the app's process is killed, the Service's is not.

Start not sticky doesn't work above kitkat, and the other onTaskRemoved not working above Marshmellow.
onTaskRemoved could be used by handled some exceptions. Did not worked on that. But try that one.

If you are using an IntentService, it has an
onHandleIntent()
method where you should place the code that needs to be executed. It is executed in a separate thread (not a UI thread where your application runs) therefore your app shouldn't affect it. When the code has finished executing, the thread is terminated and the service is stopped automatically.

I ran into the same problem and was able to resolve it by making the service run in a global process. You do this by adding the following to the manifest tag:
process="com.myapp.ProcessName"
(Make up whatever name.)
When I did this I found that my service wasn't killed (and restarted) when the app is swiped off the list. Presumably this is because the app process is killed when you swipe it off, but global service processes are not.
The disadvantage of this is that communication between your app and service now has to be via the IBinder interface; you can't directly call functions in the application or service from the other one, because they're running in different processes.

I know its much late to answer this question, but may be it can be helpful to others. This really helped me for my Music Player App.
If there are services which can be disruptive or can affect the user experience like music etc , then in that case you have to use Notification and when service is started successfully, then create the Notification and use the function
startForeground(int Notification_id,Notification);
This will run your service in background without restarting and reinvoking its methods
https://developer.android.com/reference/android/app/Service.html

Prevent Android Service From Being Killed By OS

I have created a service that is returning START_STICKY at the onStartCommand. However, after sometime, I notice that my app has been killed by the OS.
Is there any method/piece of code that I can use to prevent the app from being killed by the OS? I know this may not fall under the best practices.
Or is there some other method that we can use like repeatedly check if the app is running, and to start the app if it is not?
Your insight on this is very much appreciated.
Cheers

The best way to stop a service being killed by android is to create a persistant notification. This will make android keep the service alive at all costs because it displays something visible.

You cannot prevent your process from being killed. If OS decide to kill your processes you will be killed. Period.
The START_STICKY will not do any magic os other answer incorrectly tells - docs about that value say:
If this service's process is killed while it is started (after
returning from onStartCommand(Intent, int, int)), then leave it in the
started state but don't retain this delivered intent. Later the system
will try to re-create the service. Because it is in the started state,
it will guarantee to call onStartCommand(Intent, int, int) after
creating the new service instance; if there are not any pending start
commands to be delivered to the service, it will be called with a null
intent object, so you must take care to check for this.

How to force an application to stay open?

I have seen apps like Lookout, JuiceDefender, and MagicJack run in the background indefinitely, unless force closed by a user directly through the task manager. (And even then, in Gingerbread, it wouldn't close unless you browsed to the application that was running under "Downloaded Apps" in the settings and force closed it once you were at the menu where you have options to manage the app like "Clear Memory" and "Force Close".
I am wondering how this is accomplished? I need to do something similar for an app of mine but I don't know how to avoid the Android OS's automatic task killing.. And don't say it's not possible because if that were true, JuiceDefender, MagicJack, and Lookout would not work.

What you can have is a service that stays alive indefinitely. You achieve that returning Service.START_STICKY on your Service's onStartCommand method.
Whenever the os needs resources and chooses to kill your app, your service will be respawned as soon as the resources are available again.
Bear in mind that having an application that is continuously alive will result in consuming the phone's battery. You should (at least) notify the user with a notification that your app is still alive in the background.
On top of that, you can register a broadcast receiver for the BOOT_COMPLETED event in order to restart your service while the device gets restarted. Yet, bear in mind that this could result in eating the phone's battery and so be careful on what you are doing in the service.

I believe these apps are launching a Service when their Activity get started (i.e when onCreate() is called).
A Service keeps running when the application get paused. When the Service is launched, you may return START_STICKY in your onStartCommand.
Also, to prevent a Service from being killed by Android's memory killer, you can specify that your Service is important to the user by calling startForeground(). Android Developers website states that :
A foreground service is a service that's considered to be something
the user is actively aware of and thus not a candidate for the system
to kill when low on memory.

I am creating an app and I have to use one or more of the following super functions inside OnCreate():
onDestroy()
onPause()
onResume()
onSaveInstanceState()
to close an app completely from the memory. And also do not use Activity.finish() method. Usually Android does a pretty good job in closing the app when memory is needed, called pop out of stack and not recommended to forcefully stay in memory, unless there is a very very good reason to. Hope it helps.
You can also check the Android DOC website for more information and examples to your request.

You need to start a service. Services runs in background and is useful to push alerts.
This some links about it:
http://developer.android.com/guide/components/services.html
http://www.vogella.com/articles/AndroidServices/article.html

In the service onStartCommand method return "START_STICKY".
http://developer.android.com/guide/components/services.html
/Thomas