How to parse JSON URL in Android Studio (SDK version 23)?

Question

Java

I googled everything, but did not achieve even an elementary result - the output of an array in the log.
Did the following. Based on this answer: stackoverflow.com/a/10501619/5640806
Added public String getJSON. Compiled. Everything is fine.
Then I wrote this in onCreate: Caught an error: MainActivity.java:30: MainActivity.java:54: This is where it got stuck ... For the first time, such problems with JSON arose, it’s even a shame to write this here ... But I really hope for your detailed clarification.
String data = getJSON(url, 16);

String data = getJSON(url, 16);
c.connect();