public static ArrayList<String>getSubURLs(String urlString){ArrayList<String>list = new?ArrayList<>();try{java.net.URL url =new java.net.URL(urlString);Scanner input =new Scanner(url.openStream());int current = 0;while(input.hasNext()){? String line = input.nextLine();current =line.indexOf("http",current);while(current>0){? int endIndex= line.indexOf("\",current);if(endIndex > 0){? ? list.add(line.substring(current,endIndex));? ? current = line.indexOf("http:",endIndex);}? ?else? ? ? ? ? current = -1;}}}}求大神指教每一行的意思，注意是每一行，采納必有謝謝！