Java stream根据对象某个字段过滤重复数据:distinctByKey
一、原生的distinct()不支持按照列表里的对象某个属性去重
二、对某个字段过滤重复数据:使用HashMap
private static <T> Predicate<T> distinctByKey(Function<? super T, ?> keyExtractor) { Map<Object, Boolean> seen = new ConcurrentHashMap<>(); return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null; }
list.stream().filter(distinctByKey(User::getId)).collect(Collectors.toList());
参考:
https://www.cnblogs.com/unknows/p/13534953.html