import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Iterator;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

public class App {
    public static void main(String[] args) throws Exception {
        System.out.println("REST API olvasás");
        URL url = new URL("https://jsonplaceholder.typicode.com/users/");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.connect();

        int responseCode = conn.getResponseCode();

        if (responseCode != 200) {
            throw new RuntimeException("Http válasz: " + responseCode);
        }else {

            Object obj;
            JSONArray ja;

            try {
                JSONParser parser=new JSONParser();
                obj = parser.parse(new InputStreamReader(conn.getInputStream()));
                ja = (JSONArray) obj;
            } catch (  ParseException ex) {
                throw new IOException("JSON parser error, " + ex.getMessage(),ex);
            }            


            Iterator itr = ja.iterator();
            while(itr.hasNext()) {
                JSONObject obj2 = (JSONObject) itr.next();
                System.out.println( obj2.get("name") );
                System.out.println( ((JSONObject) obj2.get("address")).get("city") );
            }
           
        }
    }
}