I've seen some people with this same issue, however my case is a little bit different. The app must call a web service every X minutes no matter what fragment or activity is currently open. However all the cases I've seen here they give an option that works while on the same activity.
Edit: most work as a background job
You can use Firebase Jobdispatcher to implement what you need
Refer this
Related
i am currently trying to get code running as a background service.
what this code does is:
send request to server with current location of the user
receive response
parse response
save into model (singleton)
and this is set to happen in a 30 sec interval again and again.
now if my app stays in the background for too long, it will get disposed by the device and that code will not be executed anymore. what would be the right kind of background service for this usecase?
one of my main concernes is that i save my data in a singleton. but if my app is disposed this singleton will probably not exist anymore.
intent service doesnt make sense imho because it runs a one time tasks and has to be restarted from an app that might already be disposed at that point.
using the alarm manager would mean that i will have to save everything out of the app (sqllite for example) and then retrieve that data when the activity is started again which sounds rather complicated.
can someone please help me out here?
thanks in advance!
You sir needs the service of GCM
https://developers.google.com/cloud-messaging/
Thats exactly what you need for your desire ;)
But it's not less complicated as sticking to background services.
Also you can do a Hack: having two services watching your service to keep on running and itself...I swear when the User doesn't stop your app manually in the menu the System won't be able to stop them itself. Foolproof.
I do have a more general question, without any specific code. I will explain what my application does and how and what issues I can monitor. Maybe one of you had the same issues and can lead me to the problem.
The App:
It reads car diagnostic data (OnBoardDiagnostics) over Bluetooth and shows them in real-time in a ListView. I can start the update function by a "update Button".
How:
Everytime a new value is received via Bluetooth, a background Class (which handles the Stringforming) sends an Intentto notify the UI to update the ListView.
The Adapter Class of my ListView has the listening BroadcastReceiver registered and if it gets triggered, it will notify the ListView by notifyDataSetChanged().
Issues:
1.If I use an WakeLock to keep the screen on, the UI refreshing slows down after approx. 10 minutes.
2.If I press the power button, so the screen is off, it still slows down (I can see that, because I send the values to an webserver) but furthermore: If I turn the screen back on. I see the ListView stops for about 20-30 seconds and than normally continues with normal speed (not slow anymore).
So.. I think this is a very general question. I searched for WakeLock and sleep behaviour, but I couldn't find any similar issues. Maybe one of you can give me a hint, what the problem could be. Maybe one of you had a similar problem.
Any hint is appreciated!
EDIT 1:
Maybe the problem of the 2. issue is based on the lifecycles of my objects / activity.
If I press the update Button, an AsyncTask is started, which sends the Data (JSON, which contains one new value for all list items) to my Webserver. If the device screen is off, I still get the data every 2 seconds. If I turn on the screen, it stops for these 20-30 seconds as well as the UI. So I think my UI works fine. The Update Intents were sent right.
I have to check if I still receive new values in that background class, mentioned above.
Thanks to zapl
Thanks!
Except all possibilities I checked, i came across this article:
AsyncTasks for long running Operations
Short: There are some points you need to keep in mind if you are using AsyncTasks in very long running operations (>20min). My Problem was, that I used the AsyncTask as an inner Class. After a long period, when the Activity that created the Task was destroyed, the AsyncTask still kept a reference of this activity.
After I used a Bus, described in the article above, the UI worked fine!!
So, if anyone else noticed performance problems of your App, I recommend that article.
Thanks for all the other hints!
Have fun coding!
I am doing an application on Android that gets locations from a webservice and puts it on a map. The app should do it every 15 seconds. What is the best way to do this?The communicaton with the webservice is made using REST architecture and the webservice returns a JSON. Should i use a Service or AsyncTask? thanks
You'll for sure see different opinions around here regarding this topic, but I've been using ExecutorServices for a while and they work really nice. Don't forget to stop it whenever the activity pauses.
Remainder: if the application should be an always running thing (for example a GPS navigation, or some type of location based social gaming) then you might want to use a Service that will also use an ExecutorService and don't forget to put a Notification letting users know that it's still running and that they can cancel if they wish to.
Is there a way to cause my app to update itself at exactly midnight every night? I need the new content to be displayed on the app right when it hits midnight. I have an idea of how to accomplish this, but if it isn't in another thread and is in the onCreate and the app is running in the background next time it is opened it would just display the previous info and not the updated?
I could also use help accomplishing this same thing with iPhone as well.
I will clarify a bit. So all the information that is to be displayed on the app will be in the app already. I simply want the content (whats displayed) on the app to randomize and then display the new group of content only once per 24hours or at exactly midnight. Hope that makes it more clear.
Android:
You can set pre-determined times to update with AlarmManager
You can look at a snippet here: Android: How to use AlarmManager
iPhone:
With iPhone you probably have to download the content whenever you re-open the app.
Can't you just have the app update the content upon launch, or when entering the foreground in the appDelegate.
This question is very vague - but if I understand the requirements correctly you will need to serve the application's content dynamically via a content server (or some type of a CDN). In this case there could be various scenarios.
In the easiest possible implementation, you could have the application be powered by data (XML, JSON, etc...) from something like Amazon S3 and have logic within the application to know how to fetch the correct data depending on the current day.
This wouldn't be extremely difficult to implement, but it would require building some type of cross-platform framework that reads the same kind of data for each application.
Is the content available before midnight?
If so, can't you have the app download it in the background beforehand and then make it available exactly at midnight?
If not, there's surely going to be some delay anyway.
app can not update itself at least in iOS apps.
I am trying to implement a RESTful API in which I have to upload files that are relatively large for a mobile platform. The upload could take anywhere from 30 seconds to 5 minutes.
I would like my application to be completely usable while the upload takes place. I've been doing some research and I've come across a few methods from which I can't decide which is the correct solution to my problem.
These are the two things I have come across.
Using an IntentService -- handles the worker thread so I don't have to.
Using my own type of Service-- still need to implement an AsyncTask to handle the large process.
Implement an AsyncTask in a singleton file that would allow me to do all the work there but without using the service class.
My question is which method is the best -- if one isn't listed but is a more apt solution to my problem then I would appreciate suggestions.
After researching all these methods I am still also confused on one thing. Lets say I upload a 2MB files, but I want to know when it is done. For example, lets say I have a service that uploads an image and returns and imageID -- I need to be able to know when that service returns an imageID -- process that and then move on to the next upload until the rest are finished.
As always, thanks in advance.
EDIT: I forgot to specify that while uploading I want the app to be usable-- that means that I can switch activities and still have the same service run.
I used IntentService. It extends service so it basically has all the functions of the normal service, expect that it handles the threading for me so I don't have to worry about that. Its working very well at the moment.