preface

Whether you’re just starting out or you’ve been working as a Java developer for a few years, interviewing for a job is something you’ll always have to face. First of all, comb their knowledge system, targeted preparation, there will be twice the result with half the effort. We tend to focus on the technology and ignore the personnel part. In fact, the personnel interview will also affect the final result. If we do every link well, the final result will not be bad. In this summary of some Java interview questions often asked in the interview, because too many answers to the text has been summarized into the document at the end of the claim!

And gold three silver four is coming soon, many engineer friends are ready to job-hopping, so now you can start to see more interview questions, I found two more complete interview questions on the Internet, in addition to the big factory interview all solutions.

Really comprehensive, from elementary to advanced, framework, database, concurrent knowledge, and multi-enterprise interview questions collation!

• 350 Java interview question manuals compiled by several companies in 2019. PDF

This one is mainly in the senior interview questions, read that 18K above no problem ah!

Follow me to add assistant VX: Yunduoa2019 or scan the qr code below to get the above learning materials and documents

 

Here are some commonly asked interview questions

1. Data structure and algorithm

1. Linked lists and arrays?
2. Queue and stack, money and push?
3. Delete, insert, reverse list?
4. What are the conflict resolution methods for the Hash function of the Hash table?
5. Bubbling, selection, insertion, hill, merge, fast platoon, stack, bucket platoon, principle of cardinality, average time complexity, worst time complexity, space complexity, stability?
6. Improvements to bubbling and quick drain?
7. Binary search, versus variant binary search?
8. Binary tree, B+ tree, AVL tree, red black tree, Huffman tree?
9. Premiddle and subsequent traversal of binary trees: recursive and non-recursive writing, sequential traversal?
10. KMP algorithm?
11. Permutation and combination problem?
12. Greedy algorithms, divide-and-conquer algorithms?

Second, concurrent programming

1. How is the implementation principle of ReentrantLock different from Synchronized?
2. So what is the AQS framework?
3. Compare Synchronized and ReentrantLock in as much detail as possible.
4. How does ReentrantLock achieve reentrancy?
5. Besides ReetrantLock, what other concurrency tools in JUC have you been exposed to?
6. Talk about ReadWriteLock and StampedLock.
7. How do I synchronize Java threads with each other? What synchronizers have you learned about? Please introduce them separately.
8. CyclicBarrier and CountDownLatch look very similar.
9. Has Synchronized ever been used? What’s the mechanism?
10. You mentioned a lock on an object. What exactly is this “lock”? How do I determine the lock of an object?
11. What is reentrant and why is Synchronized reentrant?
12. What optimization has the JVM made to Java’s native locking?
13. Why is Synchronized unfair?
14. What is lock elimination and lock coarsening?
15. Why is Synchronized a pessimistic lock? What is the implementation principle of optimistic lock? What is the
16. Is optimism lock necessarily good?
17. What is the Java memory model, and how do threads in Java see each other’s variables?
18. Talk about what is special about volatile, and why it makes variables visible to all threads?
19. Compare volatile to Synchronized.
20. How does ThreadLocal address concurrency security?
21. When using ThreadLocal, you need to be careful.
22. How is thread pooling implemented in Java?
23. How many core construction parameters to create a thread pool?
24. How are threads created in a thread pool?
25. How do I submit a thread in a Java thread pool?

Open source framework

1. What are IOC and DI?
2. What is Spring IOC’s understanding of its initialization process?
3. What’s the difference between BeanFactory and FactoryBean?
4. What’s the difference between BeanFactory and ApplicationContext?
5. The lifecycle of the ApplicationContext context?
6. Spring Bean lifecycle?
7. How does Spring AOP work?
8. How does Spring manage transactions, the transaction management mechanism?
9. What are the different transaction propagation behaviors of Spring?
10. What design patterns does Spring use?
11. How does Spring MVC work?
12. How does Spring address loop dependencies?
13. How does Spring secure Controller concurrency?

The database

1. Four characteristics of Transactions (ACID)?
2. Database isolation levels, what problems do each level cause, and what is mysql’s default level?
3. What is the difference between InnoDB and MyISam?
4. What is the difference between the two storage engines of MYSQL (transaction, lock level, etc.)?
5. The order in which different elements (WHERE, jion, limit, group by, Having, and so on) are executed?
6. Database optimization (SQL statement optimization and indexing)?
7. There are B+ indexes and hash indexes. What’s the difference?
8. What’s the difference between a B+ index data structure and a B tree?
9. Index classification (primary key index, unique index), left-most prefix principle, in which case index failure?
10. The difference between a clustered index and a non-clustered index
11. What locks (optimistic locks pessimistic locks), select how to add an exclusive lock?
12. What’s the difference between a relational database and a non-relational database?
13. Database three paradigm, according to a certain field fee design data table?
14. Database read/write separation, master/slave replication?
15. Optimize SQL and indexes with Explain?
16. How to solve long_query?
17. Deadlock determination principle and specific scenarios, deadlock how to solve?
18. How to use varchar and char?
19. How to resolve mysql concurrency (by transaction, isolation level, lock)?
20. What are the recovery mechanisms for transactions in the event of a database crash (REDO and UNDO logs)?

Micro service

1. What are microservices?
2. How do microservices communicate independently?
3. What are the differences between springCloud and Dubbo?
4. Springboot and SpringCloud, what do you understand about them?
5. What is microservice circuit breaker? What is service degradation?
6. What are the pros and cons of microservices? Talk about the problems you encountered during the project development?
7. What do you know about the microservices stack?
8. Both Eureka and ZooKeeper can provide service registration and discovery functions. Please explain the differences between them.

conclusion

Before the interview, prepare your answers to the interview questions in advance and review your work experience in your resume. During the interview, introduce yourself to show your enthusiasm, match with the position, as well as your highlights and interesting places, remember the WWHC, STAR principles, from the position, department, enterprise level questions to the interviewer; The state of mind is stable, do not in the technical interview because there is a knowledge point is not clear and in the back of the question is not good!

The last

In view of the interview questions mentioned above, I have summarized some architecture video materials and most of the interview questions and answers involved in the interview of Java programmers in Internet companies into a document and architecture video materials, as well as a complete high-definition Java advanced architecture learning mind map for free to share with everyone (including Dubbo, Redis, Netty, Zook Eeper, Spring Cloud, distributed, high concurrency and other architecture technology materials), hope to help you review before the interview and find a good job, but also save the time of searching information on the Internet to learn.

Follow me to add assistant VX: Yunduoa2019 or scan the qr code below to get the above learning materials and documents