Here's what I did on API 29 & API 30:
1. I created a simple WiFiService class that will hold the connectivityManager:
class WifiService {
private lateinit var wifiManager: WifiManager
private lateinit var connectivityManager: ConnectivityManager
companion object {
val instance = WifiService()
}
fun initializeWithApplicationContext (context: Context) {
wifiManager = context.getSystemService(Context.WIFI_SERVICE) as WifiManager
connectivityManager = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
}
// Helper that detects if online
fun isOnline(): Boolean {
val capabilities = connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork)
if (capabilities != null) {
when {
capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> return true
capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> return true
capabilities.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET) -> return true
}
}
return false
}
}
2. Create the ConnectivityInterceptor to check for internet access:
class ConnectivityInterceptor: Interceptor {
override fun intercept(chain: Interceptor.Chain): Response {
if (!WifiService.instance.isOnline()) {
throw IOException("No internet connection")
} else {
return chain.proceed(chain.request())
}
}
}
3. Use it in Retrofit2 as follows:
class RestApi {
private val okHttpClient by lazy {
OkHttpClient.Builder()
.addInterceptor(ConnectivityInterceptor())
.build()
}
// Define all the retrofit clients
private val restApiClient by lazy {
Retrofit.Builder()
.baseUrl("http://localhost:10000")
.client(okHttpClient)
.addConverterFactory(GsonConverterFactory.create())
.build()
}
// ...
}
4. Finally initialize the WifiService as such:
class MainApplication: Application() {
companion object {
lateinit var instance: MainApplication
}
override fun onCreate() {
super.onCreate()
instance = this
setupServices()
}
private fun setupServices() {
WifiService.instance.initializeWithApplicationContext(this)
}
}
