java8 List Stream流去重复

根据list下标3的值去重复
List> collect1 = lists.stream().filter(distinctByKey(li -> li.get(3))).collect(Collectors.toList());

public static  Predicate distinctByKey(Function keyExtractor) {
    Map seen = new ConcurrentHashMap<>();
    return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
}