private static Map<Integer, List<Integer>> getUserLikes() {
List<Rating> ratings = DB.getRatings();
Map<Integer, List<Rating>> userPartitionnedRatings = DataOperation.groupByUser(ratings);
Map<Integer, List<Integer>> userLikedMovies = new HashMap<Integer, List<Integer>>();
for (Entry<Integer, List<Rating>> entry : userPartitionnedRatings.entrySet()) {
Integer userId = entry.getKey();
userLikedMovies.put(userId, new ArrayList<Integer>());
for (Rating r : entry.getValue()) {
if (r.rating() > DB.likeThreshold()) {
userLikedMovies.get(userId).add(r.movie());
}
}
}
return userLikedMovies;
}