list分组后统计
List<UserInfo> userList = Lists.newArrayList(); Map<String, Long> collect = userList.stream() .collect(Collectors.groupingBy(UserInfo::getId, Collectors.counting()));
待更新
待更新
list分组后统计
List<UserInfo> userList = Lists.newArrayList(); Map<String, Long> collect = userList.stream() .collect(Collectors.groupingBy(UserInfo::getId, Collectors.counting()));
待更新
待更新