1. Differences between final Finally Finalize

The synchronized keyword and when to use other locks in concurrent packages.

3. Have you ever encountered deadlock problems? (Deadlock principle and solution)

4. The implementation principle of HashMap and the difference between HashMap and Hashtable

5. Optimization of database and table

6. Generation of unique ID of distributed system (sequential ID needs distributed lock, optimization of sequential ID, non-sequential ID)

7. How does distributed system ensure data consistency

8. Implementation method of distributed lock

9, Redis memory model and why performance is so good (in-memory database, IO multiplexing)

Zookeeper is a process for saving data.

11, seven layer/five layer architecture, which layer is the router, TCP HTTP and other protocols which layer

12, TCP connection establishment process, disconnection process

After the second wave, a large number of packets are sent to the server. What will the server do

Java IO model

Java memory model. The role of volatile

16, Why is elasticSearch faster

17. Hbase and Hive underlying storage modes

Spring bean lifecycle, BeanFactory vs. ApplicationContext

19, The implementation principle of Spring AOP (what are the types of proxy, what is the default proxy)

Mybatis converts query results into class processes

21. What are the benefits of Springboot or SpringIOC

22. JVM garbage collector (not garbage collection algorithm), what is the garbage collector used in your project

Multithreaded communication

Threadlocal implementation principle, precautions and usage scenarios

What new technologies have you followed (new features in JDK1.8) or open source projects? What open source code have you read

How does message middleware implement remote call

27, thread pool implementation principle, several important parameters of thread pool, if the thread pool reaches the maximum number, how will the subsequent submit new task

28. Tomcat thread quantity configuration and optimization (IO intensive, CPU intensive, pressure measurement)

What is the reason why you choose kafka (kafka features), ask the deeper will ask kafka ISR mechanism, partition election

30. What are the most impressive problems or achievements you have encountered in the project

Mysql index optimization, index storage structure, execution plan

32, Redis data persistence mechanism, redis what data structure

33, CAP concept, analyze kakfa or other database types

What is CAS

35. Have you used the Spring prototype pattern

How is the Spring singleton pattern thread-safe

What kind of code is good code

Programming problem:

1, a total of 9 apples, there are 2 monkeys, a monkey take 2 apples, a monkey take 3 apples. If there were not enough apples left for each monkey, the two monkeys stopped picking apples. Simulate the above description with Java multithreading.

2. Reverse the numbers.

3. Tree traversal.

Design:

System A and system B need to interact, system A needs to update A large amount of data of system B, but the update failed, what is the solution?

The last

In view of the recent many people in the interview, I have also sorted out quite a lot of interview materials, there are also other big factories. I hope I can help you.

The answers to the above interview questions are documented in notes. Also sorted out some interview materials & the latest collection of some big factory interview questions in 2020 (all sorted into a document, a small part of the screenshots), there is a need to pay attention to the public below to obtain their own

 

The above is all the content of this article, I hope to help you learn, but also hope that you support. One key three link oh!