I'm having problem with scraping a URL with 'ö', so I found a possible solution here (implemented below)
String url = "https://www.ariva.de/deutsche_börse-aktie/bilanz-guv?page=0";
String encodedURL = URI.create(url).toASCIIString();
Document doc = Jsoup.connect(encodedURL).get();
However, I still get the error:
Exception in thread "main" org.jsoup.HttpStatusException: HTTP error fetching URL. Status=404, URL=http://www.ariva.de/deutsche_b%2525C3%2525B6rse-aktie/bilanz-guv?page=0