YouTube page scraping using Jsoup
There is nothing special to say. This is a big bunch of procedural code. You can maybe improve it by keeping references to items or navigating in them instead of re-reading them from the root :

String userLink = body.getElementById("watch7-user-header").getElementsByAttributeValue("class", "yt-user-photo yt-uix-sessionlink      spf-link").attr("href");
String userPhoto = body.getElementById("watch7-user-header").getElementsByTag("img").attr("data-thumb");

// Can be 
Element user = body.getElementById("watch7-user-header");
String userLink = user.getElementsByAttributeValue("class", "yt-user-photo yt-uix-sessionlink      spf-link").attr("href");
String userPhoto = user.getElementsByTag("img").attr("data-thumb");


If you want to change the way you parse that, you can introduce a parsing object. (https://www.javacodegeeks.com/2018/03/dont-parse-use-parsing-objects.html)