In January 2020, the latest Java finishing the interview experience (one-time Network access your fill)

Foreword

Now in 2020, I believe many people are prepared to interview ,, how to get Offer favorite, enters the dream of manufacturers, to realize their career aspirations, well-off programmer.

This article describes Liu's brother a few times by January, (one-time Network access your fill),! (Thank Liu brother of content provided)

For the interview that several companies to hold off publication, we hope to understand.

The first (Zookeeper + micro-messaging middleware service + + high concurrency architecture design)

one side

• JVM data storage model, the new generation, old generation of construction?

• java GC algorithm, when it will trigger minor gc, when it will trigger the full gc?

• Reachability analysis which considered the GC GC ROOT?

• Are you familiar with the JVM tuning parameters, which used the tuning tool?

• Java What types of locks?

• Described processing flow in the thread pool?

• Class loading mechanism, a class is loaded into the virtual machine a total of several steps, the order of these steps which is fixed, which is not fixed, why not fixed?

• hashmap is thread safe, concurrenthashmap is thread-safe, thread-safe how to achieve?

• The volatile keyword to solve the problem, the principle is to achieve what?

• What is the difference, concurrent container and container have concurrent synchronous container

Two faces

• Matters at work, and pay attention to the optimization of SQL statements

• What library or framework to use NIO

• Spring has what kinds of injection method, under what circumstances with which, ioc implementation principle

• How to locate a slow query, a service a number of SQL how you quickly locate

• Clustered index and non-clustered indexes know? What happens with the clustered index what circumstances non-clustered index

• What storage structure Nosql engine use, relational databases and NoSQL what their strengths and weaknesses and how technology selection?

• Under the micro-service architecture, if there is an order system, an inventory system, how to ensure that the transaction?

• Distributed coherence protocols raft, paxos understand it

• Zookeeper ZAB in agreement, the main algorithm selected from

Three sides

• Self introduction

• Participate in concurrent projects, from design to deployment, in accordance with the process say it again.

• You used the project-related redis, with what scene, how to use?

• Principle mysql synchronization mechanism, which has several synchronous method

• How to achieve synchronization master-slave database, how to achieve affairs

• Talk about your understanding of SOA and micro-services, as well as adjustments and challenges involved in the application layer distributed architecture to.

• 阿里系中间件metaQ及原理与现有的kafka有什么异同

• 在阿里有了解过什么中间件吗？实现原理？与其他开源消息队列有什么特点？

• 为什么选择换公司？

• 三年到五年的职业规划？

• 你有想问我的?

第二家（幻影读+分段锁+Spring Cloud+秒杀）

一面

• 简短自我介绍

• 事务的ACID，其中把事务的隔离性详细解释一遍

• 脏读、幻影读、不可重复读

• 红黑树、二叉树的算法

• 平常用到哪些集合类？ArrayList和LinkedList区别？HashMap内部数据结构？ConcurrentHashMap分段锁？

• jdk1.8中，对hashMap和concurrentHashMap做了哪些优化

• 如何解决hash冲突的，以及如果冲突了，怎么在hash表中找到目标值

• synchronized 和 ReentranLock的区别？

• ThreadLocal？应用场景？

• Java GC机制？GC Roots有哪些？

• MySQL行锁是否会有死锁的情况？

二面

• 乐观锁和悲观锁了解吗？JDK中涉及到乐观锁和悲观锁的内容？

• Nginx负载均衡策略？

• Nginx和其他负载均衡框架对比过吗？

• Redis是单线程？

• Redis高并发快的原因？

• 如何利用Redis处理热点数据

• 谈谈Redis哨兵、复制、集群

• 工作中技术优化过哪些？JVM、MySQL、代码等都谈谈

三面

• Spring Cloud用到什么东西？如何实现负载均衡？服务挂了注册中心怎么判断？

• 网络编程nio和netty相关，netty的线程模型，零拷贝实现

• 分布式锁的实现你知道的有哪些？具体详细谈一种实现方式

• 高并发的应用场景，技术需要涉及到哪些？怎样来架构设计？

• 接着高并发的问题，谈到了秒杀等的技术应用：kafka、redis、mycat等

• 最后谈谈你参与过的项目，技术含量比较高的，相关的架构设计以及你负责哪些核心编码

第三家

一面(50分钟)

• hashmap，怎么扩容，怎么处理数据冲突？怎么高效率的实现数据迁移？

• Linux的共享内存如何实现，大概说了一下。

• socket网络编程，说一下TCP的三次握手和四次挥手

• 同步IO和异步IO的区别？

• Java GC机制？GC Roots有哪些？

• 红黑树讲一下，五个特性，插入删除操作,时间复杂度？

• 快排的时间复杂度，最坏情况呢，最好情况呢，堆排序的时间复杂度呢，建堆的复杂度是多少

二面(40分钟)

• 自我介绍，主要讲讲做了什么和擅长什么

• 设计模式了解哪些？

• AtomicInteger怎么实现原子修改的？

• ConcurrentHashMap 在Java7和Java8中的区别？为什么Java8并发效率更好？什么情况下用- --

• HashMap，什么情况用ConcurrentHashMap？

• redis数据结构？

• redis数据淘汰机制？

三面（约1个小时）

• mysql实现事务的原理(MVCC)

• MySQL数据主从同步是如何实现的？

• MySQL索引的实现，innodb的索引，b+树索引是怎么实现的，为什么用b+树做索引节点，一个节点存了多少数据，怎么规定大小，与磁盘页对应。

• 如果Redis有1亿个key，使用keys命令是否会影响线上服务？

• Redis的持久化方式，aod和rdb，具体怎么实现，追加日志和备份文件，底层实现原理的话知道么?

• 遇到最大困难是什么？怎么克服？

• 未来的规划是什么？

• 你想问我什么？

第四家 （事务+集群+秒杀架构）

一面

• 常见集合类的区别和适用场景

• 并发容器了解哪些？

• 如何判断链表是否有环

• concurrentHashMap如何实现

• 集群服务器 如何application 共享

• JAVA网络编程中：BIO、NIO、AIO的区别和联系

• jvm内存模型jmm 知道的全讲讲

• JAVA的垃圾回收，标记算法和复制算法的区别，用在什么场合？

• http和https的区别，http1.x和http2.0的区别，SSL和TSL之间的区别

• GC、G1和ZGC的区别

• B+树和B树的区别，和红黑树的区别

• 内存泄漏与内存溢出的区别

• session的生命周期是多久

• 关于Mina框架了解多少？（因为我在项目里用到了Mina，所以提到了这个部分）

二面

• java cas原理

• JAVA线程池有哪些参数，如果自己设计一个线程池要考虑哪些问题？

• Java的lock的底层实现？

• mysql数据库默认存储引擎，有什么优点

• MySQL transaction isolation level, respectively, to resolve any problems.

• Four tables on track records, each around 100,000 records, how to find the best scores of the students

• Common load balancing algorithms which

• If there are 100 million Redis key, use the command keys will affect the online service

• Redis persistent way, aod and rdb, how to achieve specific, additional log and backup files, if the principle underlying implementation know what

Three sides

• Please complete draw a large site, distributed server cluster deployment diagram

• Multiple RPC request comes in, the server how to handle concurrency it

• Talk about Redis Sentinel mechanism

• Database sub-library sub-table is generally the amount of data it needs much?

• How to ensure consistent database cached and redis

• Project Message Queuing how to use? What specific business scenarios use?

• JVM-related analysis gon have used what? Specific performance tuning steps it?

• MySQL slow sql optimization in general how to do? In addition In addition there is any way to optimize?

• Line server monitoring indicators, which indicators do you think is most in need of attention? why?

• How do pressure test, compression means

• How spike module design

HR surface

• Self introduction

• How would you rate your previous three interviews

• How do you see yourself, what is your greatest core competence is

• The future of their career planning

• What kind of understanding of the technical atmosphere Ali, Ali's what open source library used

• How much salary expectations

• Finally, what do you want to know

The answer interview questions

Well Ladies and gentlemen, this article to end here! The answer questions about why the plane did not write it directly, I would say that the interview wrote down will seem very long article, (now very long ...) This will affect the readability of the article.

Well now finishing more than 1000 road company java face questions over 400-page pdf document, sub-themes have been collated.

There are hundreds of pages of Java core knowledge of PDF.

Welcome to forward, to my personal fan base (Java technology stack architecture: 644 872 653) can be obtained receive a free way, the way we seek to praise, a point of attention! Hehe