java8 按对象属性值排序详解编程语言

//按id从小到大 
List<User> sortUser = list.stream().sorted((u1, u2) -> u1.getId().compareTo(u2.getId())).collect(Collectors.toList()); 
////按id从大到小 
List<User> sortUser = list.stream().sorted((u1, u2) -> u2.getId().compareTo(u1.getId())).collect(Collectors.toList());

public class HelloWorld { 
 
    public static void main(String[] args) { 
        List<User> list = new ArrayList<>(); 
        for(int i=1;i<=10;i++) { 
            User u = new User(i, "用户-" + i); 
            list.add(u); 
        } 
        //按id从大到小排序 
        List<User> sortUser = list.stream().sorted((u1, u2) -> u2.getId().compareTo(u1.getId())).collect(Collectors.toList()); 
 
        System.out.println("排序后：" + sortUser); 
    } 
    private static class User{ 
        Integer id; 
        String name; 
 
        public User(Integer id, String name) { 
            this.id = id; 
            this.name = name; 
        } 
 
        public Integer getId() { 
            return id; 
        } 
 
        public void setId(Integer id) { 
            this.id = id; 
        } 
 
        public String getName() { 
            return name; 
        } 
 
        public void setName(String name) { 
            this.name = name; 
        } 
 
        @Override 
        public String toString() { 
            return "User{" + 
                    "id=" + id + 
                    ", name='" + name + '/'' + 
                    '}'; 
        } 
    } 
 
}

[User { 
    id = 10, name = '用户-10' 
}, User { 
    id = 9, name = '用户-9' 
}, User { 
    id = 8, name = '用户-8' 
}, User { 
    id = 7, name = '用户-7' 
}, User { 
    id = 6, name = '用户-6' 
}, User { 
    id = 5, name = '用户-5' 
}, User { 
    id = 4, name = '用户-4' 
}, User { 
    id = 3, name = '用户-3' 
}, User { 
    id = 2, name = '用户-2' 
}, User { 
    id = 1, name = '用户-1' 
}]