Answer by Elye for How do I fix 'android.os.NetworkOnMainThreadException'?

As of 2018, I would recommend to use RxJava in Kotlin for network fetching. A simple example is below.

Single.fromCallable {
        // Your Network Fetching Code
        Network.fetchHttp(url) 
    }
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .subscribe {
        // What you need to do with your result on the view 
        result -> view.updateScreen(result) 
    }