I’ve had a hard interview for half a year. Last month, with this interview question, I won the offer of Ali, byte jump and JD!

Time:2020-11-26

preface

Recently, I have received a lot of private letters from fans, some of whom have worked for several years, and some of them are about to graduate. They all come to tell me that gold, silver and ten are coming soon. I want to go to a big factory for an interview and ask me if I have any related interview questions to share. After hearing this, I also hastened to sort out a copy for you, not much to say, full of dry goods are below, friendship tips, article space is complete, all dry goods slowly watch!!!

Redis

  • What is redis?
  • Data type of redis?
  • 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 a single process and single thread?
  • What is the maximum storage capacity of a string type value?
  • What are the persistence mechanisms of redis? What are their advantages and disadvantages?
  • Redis common performance problems and solutions:
  • How to delete the expired key of redis?
  • Redis’s recycling strategy (elimination strategy)?
  • Why does redis need to put all the data in memory?
  • Do you know 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 scheme cause the entire cluster to be unavailable?
  • Which Java clients are supported by redis? Which one is recommended by the government?
  • What are the advantages and disadvantages of jedis compared with redisson?
  • How does redis set and verify passwords?
  • What is the concept of redis hash slot?
  • What is the master-slave replication model of redis cluster?
  • Is there any write loss in redis cluster? Why?
  • How are redis clusters replicated?
  • What is the maximum number of nodes in the redis cluster?
  • How to select database for redis cluster?
  • How about redis connectivity?
  • How to understand redis transaction?
  • What are the commands related to redis transactions?
  • How to set the expiration time and permanent validity of redis key?
  • How does redis do memory optimization?
  • How does the redis recycle process work?
  • What are the ways to reduce the memory usage of redis?
  • What happens when redis runs out of memory?

MySQL

  • What kinds of locks are there in MySQL?
  • What are the different tables in MySQL?
  • The difference between myism and InnoDB in MySQI database
  • What are the four transaction isolation level names supported by inmnodb in MySQL and the differences between them?
  • What’s the difference between Chae and varchr?
  • What’s the difference between a primary key and a candidate key?
  • What is MYI samchk for?
  • What happens if a table has one column defined as timestamp?
  • How do you see all the indexes defined for the table?
  • What does the% and in the iik statement mean?
  • What is the column comparison operator?
  • What’s the difference between blob and text?
  • MySQL_ fetch_ Arr ay and MySQL_ fetch_ What is the difference between objects?
  • Where will the MyISAM table be stored and also provide its storage format?
  • How does MySQL optimize distinct?
  • How to display the first 50 lines?
  • How many columns can be used to create an index?
  • What is the difference between now() and current date()?
  • What are nonstandard string types?
  • What are general SQL functions?
  • Does MySQL support transactions?
  • What field type is good for recording currency in mysel
  • What are the MySQL tables about permissions?
  • What can be the string type of a column?
  • MySQI database is used as the storage of the publishing system, with an increase of more than 50000 items a day. It is estimated that the operation and maintenance will last for three years. How to optimize it?
  • Optimization strategy of lock

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 AP module
  • Explain the JBC abstraction and dad modules.
  • Explain the object / relation mapping integration module.
  • Explain the web module.
  • Spring file
  • What is the 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 spring’s dependency injection?
  • What are the different types of IOC (dependency injection) approaches?
  • Which dependency injection method do you recommend, constructor injection or setter method injection
  • What is spring beans?
  • What does a spring bean definition contain?
  • How to provide configuration metadata for spring container?
  • How do you define the scope of a class?
  • Explains the scope of several beans that spring supports.

Java core knowledge points

There are 29 technical modules in the core knowledge of Java, which are easy to understand and understand from different angles. The key and difficult points are interpreted in all aspects. The combination of graphics and text makes learning a kind of enjoyment.

JVM

  1. thread
  2. JM memory area
  3. JVM runtime memory
  4. Garbage collection and algorithm
  5. Reference type in Java 4
  6. GC generational collection algorithm vs partition collection algorithm
  7. GC garbage collector
  8. JAVA I0/NI0
  9. JVM class loading mechanism

Java multithreading / concurrency

  1. Java Concurrent knowledge base
  2. Java thread implementation / creation mode
  3. Four thread pools
  4. Thread life cycle (state)
  5. Four ways to terminate thread
  6. The difference between sleep and wait
  7. The difference between start and run
  8. Java background thread
  9. Java lock
  10. Thread basic method
  11. Thread context switch
  12. Synchronous lock and deadlock
  13. Thread pool principle
  14. Java blocking queue principle
  15. Usage of Cycli cbarrier, countdownlatch, semaphor e
  16. The role of volatile keyword (variable visibility, disallowing reordering)
  17. How to share data between two threads
  18. Threadloca1 function (thread local storage)
  19. The difference between synchr oni Ze reentr antlock
  20. Concurrent enthashmlap
  21. Thread scheduling used in Java
  22. Process scheduling algorithm
  23. What is CAS (compare and exchange optimistic lock mechanism lock spin)
  24. What is AQS (Abstract queue synchronizer)

Spring Boot

  • What is spring boot?
  • Why use spingr
  • What are the advantages of spring boot?
  • What are the core annotations of spring?
  • How many 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 to run in a separate container?
  • What are the monitors 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 stars in springboot
  • How many ways can SPR ingboot implement hot deployment
  • How to understand the loading sequence of spring boot configuration
  • What are the core configuration files of spring boot? What are the differences between them?
  • How to integrate spring boot and ActiveMQ
  • What is javaconfig?
  • How do I reload changes on spring boot without having to restart the server?
  • What are the monitors in spring boot?
  • How to disable activator endpoint security in spring boot?
  • How to run a spring boot application on a custom port?
  • What is yaml?
  • How to realize the security of spring boot application?
  • How to integrate spring boot and ActiveMQ?
  • How to use spring boot to achieve paging and sorting?
  • What is swagger? Have you implemented it with spring boot?

Microservices

  • What is the use of pact in 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 microservice architecture work?
  • What are the advantages and disadvantages of microservice architecture?
  • What is the difference between monolithic, SOA and microservice architecture?
  • What challenges do you face when using microservice architecture?
  • What are the main differences 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 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 are spring guided actuators?
  • What is spring cloud?
  • What problems does spring cloud solve?
  • What’s the use of webmvctest annotations in spring MVC applications?
  • Can you give us the main points about rest and micro service?
  • What are the different types of microservice testing?
  • What do you know about distributed transaction?
  • What is idempotent and where is it used?
  • What is bounded context?
  • What is two factor authentication?

Mybatis

  • What is mybatis?
  • Advantages of mybaits
  • Disadvantages of mybatis framework
  • Where mybatis framework applies
  • What are the differences between mybatis and Hibernate?
  • What to do when the attribute name in the entity class is different from the field name in the table?
  • How to write fuzzy query like statement?
  • Usually, an XML Mapping file will write a Dao interface corresponding to it. What is the working principle of this Dao interface? Can methods in Dao interface be overloaded when the parameters are different?
  • How to get the auto generated key value?
  • How to pass multiple parameters in mapper?
  • What is the use of mybatis dynamic SQL? How to execute it? What are the dynamic SQL?
  • In addition to the common select | insert | updse | delete tag in XML Mapping file, what are the other tags?
  • In the XML Mapping file of mybatis, can the ID of different XML mapping files be repeated?
  • Why is mybatis a semi-automatic ORM mapping tool? What is the difference between mybatis and fully automatic?
  • One to one and one to many associated queries?
  • Mybatis implementation – there are several ways of one? How to operate it?
  • How can mybatis implement one to many in several ways?
  • Does mybatis support delayed loading? If so, what is its implementation principle?
  • First level and second level cache of mybatis
  • What is the interface binding of mybatis? What are the implementation methods?
  • What are the requirements when calling mapper interface of mybatis?
  • How many ways to write mapper?

last

If you want to make a mistake in the interview, it is very important for me to pay attention to the failure in the interview. In addition, to remind you that full review is the key to eliminate your nervous state of mind, but if you review fully, you should have much more confidence in the process of natural interview.
All the learning materials and interview materials in the above contents are arranged in my official account.Bright futureI hope you can have a successful interview and get your favorite offer!