数据去重,并统计数量
public static void main(String[] args) {
List<User> list = new ArrayList<>();
list.add(new User("一毛",23,"女"));
list.add(new User("二毛",26,"女"));
list.add(new User("三毛",24,"男"));
list.add(new User("四毛",26,"女"));
long count = list.stream().filter(s -> s.getSex().equals("女")).count();
System.out.println(count);
}