In just one autumn move, I won ByteDance. Ali, 3 offers a day, it all depends on me to gnaw this latest interview notes for 2020!

Preface

Whether it is school recruitment or social recruitment, various examinations and written examinations cannot be avoided. How to prepare for these skills is extremely important. Whether it is a written test or a test, there are rules to follow. What I mean by "rules to follow" is only to say that you can prepare in advance for technical tests. This is the principle of not fighting unprepared battles. The following is for everyone , Describes from interview preparation to the final offer and provides a very detailed list. It is recommended to read it from the beginning. If the foundation is good, you can also select the chapters you need to view

Redis

What is Redis?
Redis data type?
What are the benefits of using Redis?
What are the advantages of Redis over Memcached?
What are the differences between Memcache and Redis?
Is Redis single-process single-threaded?
What is the maximum capacity that a string value can store?
What is the persistence mechanism of Redis? Their advantages and disadvantages?
Common Redis performance problems and solutions:
Redis expired key deletion strategy?
Redis recycling strategy (elimination strategy)
Why does Redis need to put all data in memory?
Do you understand the synchronization mechanism of Redis?
What are the benefits of pipeline, why use pipeline?
Have you ever used Redis cluster, what is the principle of cluster?
Under what circumstances will the Redis cluster solution cause the entire cluster to be unavailable?
What are the Java clients supported by Redis? Which is the official recommendation?
What are the advantages and disadvantages of Jedis and Redisson?
How to set password and verify password in Redis?
Talk about the concept of Redis hash slot?
What is the master-slave replication model of Redis cluster?
Will there be write operations lost in the Redis cluster? Why?
How is replication between Redis clusters?
What is the maximum number of nodes in a Redis cluster?
How to choose a database for Redis cluster?
How to test the connectivity of Redis?
How to understand Redis transactions?
What are the commands related to Redis transactions?
How to set the expiration time and permanent validity of Redis key?
How does Redis optimize memory?
How does the Redis recycling process work?
Are there any ways to reduce Redis's memory usage?
What happens when Redis runs out of memory?

MySQL

What kind of locks are there in MySQL?
What are the different tables in MySQL?
Briefly describe the difference between MyISM and InnoDB in the MySQI database
The names of the four transaction isolation levels supported by InmnoDB in MySQL, and the difference between the levels?
What is the difference between CHAE and VARCHR?
What is the difference between primary key and candidate key?
What is myi samchk used for?
If a table has one column defined as TIMESTAMP, what will happen?
How do you see all the indexes defined for the table?
What does the% sum in the IIK statement mean?
What is the column comparison operator?
What is the difference between BLOB and TEXT?
What is the difference between MySQL_ fetch_ arr ay and MySQL_ fetch_ object?
Where will the MyISAM table be stored and also provide its storage format?
How does MySQL optimize DISTINCT?
How to display the first 50 rows?
How many columns can be used to create an index?
What is the difference between NOW () and CURRENT DATE ()?
What is a non-standard string type?
What are general SQL functions?
Does MySQL support transactions?
What field type is good for recording currency in MySeL
What are the MySQL tables related to permissions?
What can be the string type of the column?
The MySQI database is used for the storage of the publishing system, with an increase of more than 50,000 entries a day. It is expected to operate and maintain for three years. How to optimize?
Lock optimization strategy

Spring

What is spring?
What are the benefits of using the Spring framework?
What modules does Spring consist of?
Core container (application context) module.
BeanFactory-BeanFactory implementation example.
XMLBeanFactory
Explain the AP module
Explain the JBC abstraction and DAD module.
Explain the object/relational mapping integration module.
Explain the WEB module.
Spring configuration file
What is Spring IOC container?
What are the advantages of IOC?
What is the usual implementation of ApplicationContext?
What is the difference between Bean Factory and Applicati on contexts?
What does a Spring application look like?
What is dependency injection in Spring?
What are the different types of IOC (dependency injection) methods?
Which method of dependency injection do you recommend, constructor injection or Setter method injection? Spring Beans
What are Spring beans?
What does a Spring Bean definition contain?
How to provide configuration metadata to the Spring container?
How do you define the scope of the class?
Explain the scope of several beans supported by Spring.

The notes are shared with friends who need to interview and brush questions, and I wish everyone smoothly get the offer you want. This information mainly contains a lot of knowledge points, including basic knowledge, Java collections, JVM, multi-threaded concurrency, Spring principle, microservices, Netty and RPC, Kafka, diary, design pattern, Java algorithm, database, Zookeeper, distributed cache, data structure, etc.

Java core knowledge points

There are 29 technical modules in the Java core knowledge points, which are explained in a simple way from various angles, and the key and difficult points are interpreted in all aspects. The combination of pictures and texts is easy to understand, making learning a pleasure.

JVM

Thread
JM memory area
JVM runtime memory
Garbage collection and algorithms
Four reference types in JAVA
GC generational collection algorithm vs partition collection algorithm
GC garbage collector
JAVA I0 / NI0
JVM class loading mechanism

Java multithreading/concurrency

JAVA Concurrent Knowledge Base
JAVA thread implementation / creation method
4 types of thread pools
Thread life cycle (state)
4 ways to terminate threads
The difference between sleep and wait
The difference between start and run
JAVA background thread
JAVA lock
Basic thread method
Thread context switch
Synchronization and deadlock
Principle of Thread Pool
JAVA blocking queue principle
Usage of Cycli cBarrier, CountDownLatch, Semaphor e
The role of the volatile keyword (variable visibility, reordering prohibited)
How to share data between two threads
ThreadLoca1 function (thread local storage)
The difference between synchr oni ze Reentr antLock
Concur entHashMlap concurrency
Thread scheduling used in Java
Process scheduling algorithm
What is CAS (Compare and Exchange-Optimistic Lock Mechanism-Lock Spin)
What is AQS (Abstract Queue Synchronizer)

Spring Boot

What is Spring Boot?
Why use Spr ingBoot
What are the advantages of Spring Boot?
What is the core annotation of Spring Boot? Which annotations are mainly composed of?
What are the ways to run Spring Boot
How to understand Starters in Spring Boot?
How to run some specific code when Spring Boot starts?
Does Spring Boot need a separate container to run?
What is a monitor in Spring Boot?
How to use Spring Boot to implement exception handling?
How do you understand Starters in Spring Boot
What are the commonly used star ters in Springboot
What are the ways to implement hot deployment in Spr ingBoot
How to understand Spring Boot configuration loading order
What are the core configuration files of Spring Boot? What are their differences?
How to integrate Spring Boot and ActiveMQ
What is JavaConfig?
How to reload changes on Spring Boot without restarting the server?
What is a monitor in Spring Boot?
How to disable Actuator endpoint security in Spring Boot?
How to run Spring Boot application on a custom port?
What is YAML?
How to achieve the security of Spring Boot applications?
How to integrate Spring Boot and ActiveMQ?
How to use Spring Boot to implement paging and sorting?
What is Swagger? Have you implemented it with Spring Boot?

Microservice

What is the use of PACT in the microservice architecture?
What are the advantages of microservice architecture?
What are the characteristics of microservices?
What are the best practices for designing microservices?
How does the microservice architecture work?
What are the advantages and disadvantages of the microservice architecture?
What is the difference between monolithic, SOA and microservice architecture?
What challenges do you face when using microservice architecture?
What is the main difference between SOA and microservice architecture?
What are the characteristics of microservices?
What is domain-driven design?
Why do you need domain-driven design (DDD)?
What is the ubiquitous language?
What is cohesion?
What is coupling?
What is reST 1 RESTful and what is its purpose?
What do you know about Spring Boot?
What is a Spring boot actuator?
What is Spring Cloud?
What problems does Spring Cloud solve?
What is the use of WebMvcTest annotation in Spring MVC application?
Can you give some points about rest and microservices?
What are the different types of microservice testing?
What do you know about Distributed Transaction?
What is Idempotence and where is it used?
What is a bounded context?
What is two-factor authentication?

Mybatis

What is Mybatis?
Advantages of Mybaits
Disadvantages of MyBatis framework
MyBatis framework applicable occasions
What is the difference between MyBatis and Hibernate?
What should I do when the attribute name in the entity class is different from the field name in the table?
How to write a fuzzy query like statement?
Usually every Xml mapping file will write a Dao interface corresponding to it. May I ask, what is the working principle of this Dao interface? Can the method be overloaded when the parameters of the Dao interface are different?
How to get the automatically generated (live) key value?
How to pass multiple parameters in mapper?
What is the use of Mybatis dynamic sql? The principle of execution? What are the dynamic sql?
In the Xml mapping file, besides the common select |insert |updse |delete tags, what other tags are there?
In the Xml mapping file of Mybatis, can the id be repeated for different Xml mapping files?
Why is Mybatis a semi-automatic ORM mapping tool? What is the difference between it and fully automatic?
One-to-one, one-to-many related queries?
MyBatis implementation-there are several ways to one? How to operate?
How does MyBatis implement one-to-many in several ways?
Does Mybatis support lazy loading? If so, what is its implementation principle?
Mybatis's primary and secondary cache
What is the interface binding of MyBatis? What are the ways to implement it?
What are the requirements when using MyBatis's mapper interface to call?
What are the ways to write Mapper?

At last

All the learning materials and interview materials in the above content are shared with you for free. Friends in need can click here to download by themselves. Download code: csdn . For programmers, technical learning is "defensive". We Learning for the future, in order to apply in new projects, so you want to be able to have your own core competitiveness in the future market, occupy a certain position, persist in learning and constantly improve yourself is the real reason for being unbeaten in the interview!