How to show a modal window in Android or JS if there is no internet connection?

Question

Java

I'm doing a project in Android Studio and the very essence of the question is - How to show a modal window with the error "You have no Internet, check your connection" if the user is disconnected from the Internet?

Answer 1

https://stackoverflow.com/questions/6362314/wifi-c...
https://stackoverflow.com/questions/25678216/andro...
And the like. Do not forget that there is still wired Internet