根据b站UP主狂神说JUC课程所写的个人学习笔记
视频地址:https://www.bilibili.com/video/BV1B7411L7tE?from=search&seid=14761503393031794075
什么是Stream流式计算
大数据:存储+计算
存储:集合,mysql本质就是存储东西的
计算都应该交给流来操作
//选出年龄必须大于23,id为偶数,用户名大写,倒着排序,只输出一个用户
public class Test {
public static void main(String[] args) {
User u1 = new User(1,21,"a");
User u2 = new User(2,22,"b");
User u3 = new User(3,23,"c");
User u4 = new User(4,24,"d");
User u5 = new User(6,25,"e");
//集合就是存储
List<User> users = Arrays.asList(u1, u2, u3, u4, u5);
//计算交给流
//链式编程
users.stream()
.filter(user -> {return user.getId()%2==0;})
.filter(user -> {return user.getAge()>23;})
.map(user -> {return user.getName().toUpperCase();})
.sorted((uu1,uu2)->{return uu2.compareTo(uu1);})
.limit(1)
.forEach(System.out::println);
}
}