こんにちは、ParseObject から ParseUser オブジェクトを取得する方法を考えていました。ParseQuery は List を返すため、これを行う必要があります。これが私のコードです。助けてくれてありがとう!
        // get the currentUser
        currentUser = ParseUser.getCurrentUser();
        List<ParseObject> friendsList = currentUser.getList("friendsList");
        // search for the person the user wants to add as a friend
        List<ParseObject> userResults = new ArrayList<ParseObject>();
        ParseQuery otherUserQuery = ParseUser.getQuery();
        otherUserQuery.whereEqualTo("username", "jyo2");
        try {
            userResults = otherUserQuery.find();
        } catch (ParseException e1) {
            // fail
            e1.printStackTrace();
        }
        // get the friend from the query if there was one and add it to the
        // currentUser friends list
        if (userResults.size() != 0) {
            ParseObject currentObject = userResults.get(0);
            friendsList.add(currentObject);
            currentUser.put("friendsList", friendsList);
        }
        // save the update
        try {   
            currentUser.save();
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        // try to view the friends
        List<ParseObject> currentFL = currentUser.getList("friendsList");
        ParseObject currentPU = currentFL.get(0);
        System.out.println("THIS IS SIZE" + currentFL.size());
        System.out.println(currentPU.get("name"));