Gold, silver and four want to change jobs, so we should seize the time to make up

  After the Spring Festival, the recruitment season is coming , I don't know if everyone is ready , Facing the recruitment season of gold, silver and four , If there is no careful preparation, I think it is irresponsible to myself ; Just us Java For the programmer , Most companies generally interview by introducing themselves + Project introduction + Project details / Difficult questions + Assessment of basic knowledge points + Algorithmic problem this flow down .

After seeing these hundreds of interview questions on niuke.com last week , It's so hard to see all the comments ！ It's too hard , I was deeply attracted by it , It took a week to parse them all out and make this document , Sent to fans of recent interviews , After the explosion, he was able to get several large factories Offer！

What I share today is the interview question bank most frequently used by Internet enterprises , After careful sorting , All questions have been updated with detailed answers , For those difficult to understand, technical documents have been specially made to facilitate everyone's reading and learning .

This sharing involves a total of knowledge points ：Java Basics 、 Multithreading 、JVM、Spring、SpringMVC、SpringCloud、Spring Boot、 High concurrency 、Redis、kafka、 Message middleware MQ、Dubbo、Tomcat、 Network protocol 、 data structure 、MySQL、MyBatis、 Design patterns 、 Algorithm etc. .

Catalog :

Because there are many questions , Space limitation , The interview questions in the article are not all shared with detailed analysis , But it's a detailed PDF file

Looking at the interview questions can be for an interview , It can also be a kind of leakage of what you have learned , Learn more about some core knowledge points

 MyBatis  Interview questions

1、 What is? Mybatis？

2、Mybaits The advantages of ：

3、MyBatis Disadvantages of the framework ：

4、MyBatis The frame is suitable for ：

5、MyBatis And Hibernate What are the differences ？

6、#{} and ${} What's the difference ？

7、 When the property name in the entity class is different from the field name in the table , What do I do ？

8、 Fuzzy query like How to write a sentence ?

The first 1 Kind of ： stay Java Add in code sql wildcard .

string wildcardname = “%smi%”;
 
list<name> names = mapper.selectlike(wildcardname);
 
<select id=”selectlike”>
 
select * from foo where bar like #{value}
 
</select>

...................MyBatis Interview questions 27 Avenue , Too much content , Try to be concise , Small partners who need the whole document can follow wechat official account 【 Qing Dynasty programmer 】 receive

ZooKeeper Interview questions

ZooKeeper Is an open source distributed coordination service , Created by Yahoo , yes Google Chubby Open source implementation . Distributed applications can be based on ZooKeeper Implementation such as data publishing / subscribe 、 Load balancing 、 Naming service 、 Distributed coordination / notice 、 Cluster management 、Master The election 、 Configuration maintenance , Name service 、 Distributed synchronization 、 Distributed lock and distributed queue .

• zookeeper Load balancing and nginx Load balancing difference
• Zookeeper Watcher Mechanism -- Data change notice
• Client registration Watcher Realization
• zookeeper How to ensure the order consistency of transactions ？
• Zookeeper For nodes watch Are monitoring notifications permanent ？ Why not forever ?
• zk How are node outages handled ？
   

Zookeeper It's also a cluster , The recommended configuration is no less than 3 Servers .Zookeeper We also need to ensure that when a node goes down , Other nodes will continue to provide services . If it's a Follower Downtime , also 2 Servers provide access , because Zookeeper There are multiple copies of the data on , Data is not lost ; If it's a Leader Downtime ,Zookeeper New ones will be elected Leader.ZK The mechanism of clustering is that as long as more than half of the nodes are normal , The cluster can provide services normally . Only in ZK Too many nodes , Only half or less of the nodes can work , Clusters fail . therefore 3 Of nodes cluster You can hang up 1 Nodes (leader You can get 2 ticket >1.5)2 Of nodes cluster You can't hang up on anything 1 There are nodes (leader You can get 1 ticket <=1)

Dubbo Interview questions

Spring Eureka From open source to closed source ,Consul Is on the rise , and Dubbo Start to update again . At present, there are still many companies using dubbo We also need to continue to learn .

• Why use  Dubbo？

• What communication framework is used by default , Is there any other choice ?

• Is the service call blocking ？

• What kind of registration center do you usually use ？ Is there any other choice ？

• What serialization framework is used by default , What else do you know ？

• Dubbo What are the layers of the overall architecture design of ?

...............

Elasticsearch Interview questions

• elasticsearch To understand how much , Talk about your company es Cluster architecture of , Index data size , How many pieces are there , And some Tuning Tools .
• elasticsearch What to do if there is too much index data , How to tune , Deploy
• elasticsearch How to achieve master Elected
• Elasticsearch At deployment time , Yes Linux What are the optimization methods for the setting of
• Describe in detail Elasticsearch The process of updating and deleting documents .
• Elasticsearch At deployment time , Yes Linux What are the optimization methods for the setting of ？

...........

Redis Interview questions

With the development of applied R & D technology ,Redis Cache technology has become one of the necessary abilities for background research and development students . In the process of interview in many companies , All must be examined Redis The mastery of knowledge points .

• Use Redis What are the benefits ？
• Redis Single process, single thread ？
• Redis What is the persistence mechanism of ？ Advantages and disadvantages of each ？
• Redis Common abnormal problems and solutions （ An avalanche , through ...）
• redis Delete strategy of expired key ？
• Why? redis You need to put all the data in memory ？
• Redis What is the master-slave replication model of a cluster ？
• Redis key How to set the expiration time and permanent validity of ？
   

.......... Try to be concise , Small partners who need the whole document can follow wechat official account 【 Qing Dynasty programmer 】 receive

MySQL Interview questions

Nowadays, the Internet industry uses the most MySQL, But for advanced Web Interviewers , Especially for looking for 30k The next job seeker , quite a lot MySQL Relevant knowledge points will basically involve , If in an interview , Your relevant knowledge is vague and irrelevant , Most of the interviewers in better companies , I'm not interested in you , After all, a little bit of a big project , In the end, it will let you go deep into the database , And most of the final bottlenecks will first appear in the database .

• MySQL Related storage engines .
• MySQL Index implementation principle .
• MySQL The database lock .
• MySQL Of SQL tuning .
• MySQL Sub table sub database global ID.

...............

Java Concurrent programming

• stay java The difference between the local thread and the guard thread in ？
• What is context switching in multithreading ？
• Java What is the thread scheduling algorithm used in ？
• What is a thread group , Why is it Java Not recommended in ？
• stay Java in Executor and Executors The difference between ？
• Three elements of concurrent programming ？
• What is a thread pool ？ What are the ways to create ？

.........

 Spring Interview questions

1. Talk about right Spring IoC The understanding of the ？

2. Talk about right Spring DI The understanding of the ？

3. BeanFactory Interface and ApplicationContext What's the difference between interfaces ？

4. Please introduce what you are familiar with Spring Core class , And explain what it does ？

5. Introduce to you Spring The understanding of the affairs of ？

6. Introduce to you Spring The transaction implementation of ？

7. What is? Spring Dependency injection of ？

..........

Kafka Interview questions

• Kafka  With the traditional MQ There are three key differences between messaging systems

• Let me talk about it. kafka Of ack Three mechanisms of

• Consumer failure , How to solve the problem of live lock ？

• kafka Distributed （ It's not a single machine ） Under the circumstances , How to ensure the sequential consumption of messages

• kafka How not to consume duplicate data ？ For example, deduction , We can't repeat the button .

....

Reader benefits

Because there are many questions , Space limitation , The interview questions in the article are not all attached with detailed analysis , I hope all colleagues can understand it, but it has been sorted into a detailed PDF file . No more nonsense, you need more PDF You can reply by private letter after paying attention to “666” receive